ISRS 2005 International Congress and Exhibition 11-15 September - Brussels, Belgium
2 0 s 0 l 5 se , I us www.isrs2005.com SRS in Br © ADAGP, Paris 2005 ISRS thanks the Magritte Foundation for its support
Under the High Patronage of Her Majesty the Queen Fabiola of Belgium
7th International Stereotactic Radiosurgery Society Congress
A multidisciplinary artistry for the brain and the body FINAL PROGRAM AND BOOK OF ABSTRACTS Congress Venue
The ISRS 2005 congress and exhibition take place in the heart of the business and commercial district of Brussels, place Rogier. The 2nd and 3rd floor of the Sheraton hotel have exclusively been reserved for the ISRS 2005.
Address Sheraton Hotel Brussels 3, Place Rogier • B-1210 Brussels Phone : +32.2.224.31.11 • Fax : +32.2.203.34.56 Website : www.sheraton.com/brussels
ISRS 2005 Floorplan Ground Floor Welcome and registration desks
1st Floor Speakers slide center : room Tempo
2nd Floor
3rd Floor
Organized by , International Congress and Events Organizers Table of Contents
FINAL PROGRAM
Congress Program Overview 4 Scientific Program 22 Introduction 22 Welcome Messages 8 Scientific Sessions Descriptions 22 Slide Center & Oral Presenters Guidelines 23 ISRS 2005 Committees & Organisers 10 Poster Presenters Guidelines 24 Disclaimer & Guest Editor 25 The ISRS Society 12 Daily Scientific Program 26 Sunday Sept. 11, 2005 26 Registration Information 13 Monday Sept. 12, 2005 27 Registration Desks 13 Tuesday Sept. 13, 2005 49 On-site Registration 14 Wednesday Sept. 14, 2005 57 Registration fees include 15 Thursday Sept. 15, 2005 79
Congress information & services 16 Exhibition 87 Book of abstracts 16 Description 87 Accreditation 16 Floorplan & List of Exhibitors 88 Awards 16 Badges 16 Sponsors & Exhibitors Activities 90 Bags Contents 16 Cancellation 17 Congress Social Program 97 Catering 17 Opening Ceremony & Welcome Reception 97 Certificate of Attendance 17 Gala Dinner & Concert of Toots Thielemans 97 Cloakroom 17 Disabled Persons 18 Tours & Accompanying Persons Program 99 Display Areas 18 Disclaimer 18 About Brussels 102 Dress Code 18 First Aid 18 Area Map 106 Hotels 18 Internet Area & Wi-fi 18 Language 19 Lost and Found 19 BOOK OF ABSTRACTS Lottery 19 Meeting Rooms 19 Oral Presentations Abstracts 107 Meeting Point 20 Posters Abstracts 201 Messages 20 Sponsored Sessions Abstracts 285 Parking 20 Personal Insurance 20 Photocopy & Fax 20 Press 20 Copyright: ISRS 2005, Brussels, August 2005 Security 21 The information and statements herein are believed to be reliable, but are not to be construed as a warranty or representation for which the authors Smoking 21 assume legal responsibility. No part of the editorial content may be trans- Special Needs 21 lated, transcribed or reproduced in any way without prior written permis- Vouchers 21 sion from ISRS 2005.
03
Congress Program Overview
Sunday 11/09/05 Monday 12/09/05
11h00 - 17h00 REGISTRATION DESKS 07h00 - 18h00 REGISTRATION DESKS
14h00 - 18h00 SLIDE CENTER - Tempo 07h00 - 17h30 SLIDE CENTER - Tempo
16h30 - 20h00 EXHIBITION 08h30 - 18h00 EXHIBITION BS1 - Rembrandt BS2 - Permeke BS3 - Willumsen Frameless Combined Radiosurgical Strategies Approaches Pathology of Brain 07h30 - 08h30 Tumors and Experimental Background PS1 - Nation Conformity & Selectivity, Lung Cancer, 08h45 - 10h00 Craniopharyngiomas, Spinal Metastases
10h00 - 17h30 POSTER VIEWING - Holbein/Turner/Foyer
10h00 - 10h30 COFFEE BREAK & EXHIBITION
P1 - POSTER SESSION - Holbein/Turner/Foyer General, Extracranial Radiosurgery,Vestibular 10h30 - 11h30 Schwannomas, Arteriovenous Malformations, Metastases, Gliomas, Radiobiology, Medical Imaging, Proton Therapy P1-1 to P1-70
PRE-CONGRESS OS1 - Nation OS2 OS3 - Willumsen SYMPOSIUM & LUNCH * Large Permeke/Rembrandt Gliomas Permeke/Rembrandt 11h30 - 12h30 Arteriovenous Radiobiology Organised by Accuray Malformations 12h30 - 16h30 Pioneering Techniques in CyberKnife Radiosurgery LUNCH & EXHIBITION 12h30 - 14h00 * Registration required Supported by BrainLAB
SPONSORED SEMINAR, by BrainLAB - Nation OPENING CEREMONY 13h00 - 13h45 Nation Novalis for Functional Neurosurgery Welcome Session The EU OS4 - Nation OS5 - Permeke/Rembrandt 17h00 - 18h00 14h00 - 15h00 Competitiveness Vestibular Schwannomas 1 Lung Tumors 1 and the Socio-economic Challenges of OS6 - Nation OS7 - Permeke/Rembrandt 15h00 - 16h00 Radiosurgery Vestibular Schwannomas 2 Lung Tumors 2
16h00 - 16h30 COFFEE BREAK & EXHIBITION
WELCOME RECEPTION OS8 - Nation OS9 - Permeke/Rembrandt 16h30 - 17h30 18h00 - 20h00 & OFFICIAL OPENING Vestibular Schwannomas 3 Other Tumors OF THE EXHIBITION FREE EVENING 04 Tuesday 13/09/05
REGISTRATION DESKS 07h00 - 13h00
SLIDE CENTER - Tempo 07h00 - 12h30
EXHIBITION 08h30 - 13h00
BS4 - Rembrandt BS5 - Permeke BS6 - Willumsen What Risk of Cancerogenesis Radiosurgery for Physics – New Technologies in Radiotherapy Arteriovenous Malformations 07h30 - 08h30 and Radiosurgery?
PS2 - Nation Data Blitz Update 1 Extracranial Radiosurgery 08h45 - 10h00 Data Blitz Update 2 Vestibular Schwannomas Brain metastases
POSTER VIEWING - Holbein/Turner/Foyer 10h00 - 12h30
COFFEE BREAK & EXHIBITION 10h00 - 10h30
OS10 - Nation OS11 - Permeke/Rembrandt OS12 - Willumsen Brain Metastases 1 Meningiomas 1 Physics – General 10h30 - 11h30
OS13 - Nation OS14 - Permeke/Rembrandt OS15 - Willumsen Brain Metastases 2 Meningiomas 2 Physics – Leakage 11h30 - 12h30
ISRS Board Meeting - Mezzo 12h30 - 14h00
FREE AFTERNOON
FREE EVENING 05 Congress Program Overview
Wednesday 14/09/05
07h00 - 18h00 REGISTRATION DESKS
07h00 - 17h30 SLIDE CENTER - Tempo
08h30 - 18h00 EXHIBITION
BS7 - Rembrandt BS8 - Permeke BS9 - Willumsen Epilepsy Brain Metastases Physics - Quality Assurance 07h30 - 08h30
PS3 - Nation Data Blitz Update 3 Brain Metastases 08h45 - 10h00 Data Blitz Update 4 Physics Comparative Technologies
10h00 - 17h30 POSTER VIEWING - Holbein/Turner/Foyer
10h00 - 10h30 COFFEE BREAK & EXHIBITION - Offered by BioScan & Dixi medical
P2 - POSTER SESSION - Holbein/Turner/Foyer Physics, Molecular Imaging, Meningiomas, Functional Radiosurgery, 10h30 - 11h30 Spinal Radiosurgery, Pituitary Tumors P2-1 TO P2-68
OS16 - Nation OS17 - Permeke/Rembrandt OS18 - Willumsen Functional Radiosurgery 1 Imaging Arteriovenous Extracranial Radiosurgery 1 11h30 - 12h30 Malformations
12h30 - 14h00 LUNCH & EXHIBITION - Supported by Medtronic
SPONSORED SEMINAR, by Medtronic - Nation 13h00 - 13h45 The Complementary Role of Intra Operative MRI and Radiosurgery
OS19 - Nation OS20 - Permeke/Rembrandt 14h00 - 15h00 Functional Radiosurgery 2 Physics – News
OS21 - Nation OS22 - Permeke/Rembrandt 15h00 - 16h00 Functional – Trigeminal Neuralgia 1 Physics – Quality Assurance
16h00 - 16h30 COFFEE BREAK & EXHIBITION
OS23 - Nation OS24 - Permeke/Rembrandt 16h30 - 17h30 Functional – Trigeminal Neuralgia 2 Spine
17h30 - 18h00 ISRS Business Meeting - Nation (for Society Members only) GALA DINNER Plaza Theater - Théâtre Le Plaza 19h30 - 23h00 Concert of Toots Thielemans 06 Thursday 15/09/05
REGISTRATION DESKS 07h00 - 13h30
SLIDE CENTER - Tempo 07h00 - 12h30
EXHIBITION 08h30 - 14h00
BS10 - Rembrandt BS11 - Permeke BS12 - Willumsen Spinal Stereotactic Vestibular Schwannomas Pituitary Tumors : Radiotherapy Hearing Preservation Radiosurgery 07h30 - 08h30 or Radiotherapy?
PS3 - Nation Data Blitz Update 5 Functional Radiosurgery 08h45 - 10h00 Data Blitz Update 6 Spinal Radiosurgery Combined Strategies, Trigeminal Neuralgia, Cancerogenesis
POSTER VIEWING - Holbein/Turner/Foyer 10h00 - 12h30
COFFEE BREAK & EXHIBITION 10h00 - 10h30
OS25 - Nation OS26 - Permeke/Rembrandt OS27 - Willumsen Arteriovenous Pituitary & MOLECULAR IMAGING - PET Malformations 1 Craniopharyngiomas 10h30 - 11h30
OS28 - Nation OS29 - Permeke/Rembrandt OS30 - Willumsen Arteriovenous Extracranial Radiosurgery 2 Imaging 2 Malformations 2 11h30 - 12h30
CLOSING SESSION - Nation Fabrikant Lecture, Young Neurosurgeon Award, Best Poster Award, 12h30 - 13h30 Lottery, Closing Speaches
CONGRESS AREAS SESSIONS CODES Meeting room Nation : 2nd floor PS: Plenary session Meeting rooms Rembrandt, Permeke, Willumsen : 3rd floor OS: Oral Session Slide center Tempo : 1st floor P: Poster session Exhibition & catering area : 2nd floor BS: Breakfast seminar Posters areas Holbein, Turner, Foyer : 3rd floor
07 Welcome Messages
A word from the Local Organising Committee of the ISRS 2005 Welcome to our ISRS 2005 Scientific Congress ! We are proud to welcome you to the 7th International Stereotactic Radiosurgery Society Congress, under the High Patronage of Her Majesty the Queen Fabiola of Belgium.
Welcome to Brussels, our city We are pleased to offer you as a setting for the congress, the city of Brussels with its special architectural charm and culinary specialties. But Brussels is not only that, it offers much more opportunities in term of social activity and has a tradition in hosting guests from all over the world. Moreover, it is a pleasure to welcome you in the year when Belgium is celebrating its 175th anniversary.
Welcome among the multidisciplinary attendants The unique multidisciplinary environment will allow you to meet attendees from various countries and to elevate and share your knowledge in the perpetually evolving field of Radiosurgery.
Thank you Special thanks to Prof. Jean Régis, Chairman of the scientific committee and to its members that have put together such a strong and well-balanced program covering scientific breakthroughs and key developments in the major fields of our activity.
Also, this diversified program was made possible by the many proposals for topics, lectures, speakers and posters covering a wide range of topics in cranial and extracranial pathologies, radiology, new technologies, physics, …
The ISRS 2005 congress would not have been possible without the support of the sponsors and the exhibitors, warmly recognized in this program and during the entire congress.
Your very attendance is of the greatest importance: thank you for being here in Brussels and demonstrating the value of communicating ideas in the field of Radiosurgery.
The congress is all yours !
Yours sincerely,
On behalf of the local organising and host committee
Professor Marc Levivier Professor Jacques Brotchi Chairman of the Congress Honorary Chairman Erasme Hospital, Brussels Erasme Hospital, Brussels
Professor Dirk Verellen Professor Paul Van Houtte Co-Chairman Co-Chairman AZ VUB, Brussels Bordet Institute, Brussels 08 Welcome Messages
A word from the President of the ISRS
On behalf of the organising committee and leadership of the International Stereotactic Radiosurgery Society, we welcome you to the 2005 meeting !
The venue for scientific interaction is superb and we know that you will enjoy all that Brussels has to offer.
The scientific program committee under Prof. Jean Régis and with the helpful contribution of David Wikler, has put together a program that will emphasize both brain and body radiosurgery, stereotactic imaging, new technologies, and fractionation approaches. So much is happening in our field, and this meeting will be a superb opportunity to evaluate clinical outcomes and new concepts.
I would like to thank the meeting committee under Prof. Marc Levivier and Prof. Jacques Brotchi, who have worked so hard to plan, develop, and administrate this meeting.
The meeting received a record number of innovative abstracts and authors of accepted abstracts are invited to submit formal manuscripts for consideration towards publication in Radiosurgery, the ISRS journal.
Take time to visit the exhibits and explore new technologies. If you are not an ISRS member, visit the registration area and obtain information on membership. On behalf of the ISRS board of directors, we welcome you to Belgium.
Douglas Kondziolka, M.D. ISRS President Pittsburgh, USA
09 ISRS 2005 Committees & Organisers
ISRS 2005 Local Organising Committee Marc Levivier Jacques Brotchi Chairman of the congress Honorary Chairman Neurosurgery Neurosurgery Erasme Hospital, Brussels Erasme Hospital, Brussels
Paul Van Houtte Dirk Verellen Co-Chairman Co-Chairman Radiation Oncology Radiation Oncology Bordet Institute, Brussels AZ VUB, Brussels
Nicolas Massager Danielle Balériaux Treasurer Medical Imaging Neurosurgery Erasme Hospital, Brussels Erasme Hospital, Brussels
Gyorgy Szeifert Jean D'Haens Neurosurgery Erasme Hospital, Neurosurgery Brussels and National Institute AZ VUB, Brussels of Neurosurgery, Budapest
Stéphane Simon Medical Physics Bordet Institute, Brussels
ISRS 2005 Scientific Committee Radiation Oncology Medical Imaging
Rita Enghenhart-Cabillic Wan-Yuo Guo Marburg, Germany Taipei, Taiwan
John C. Flickinger David Wikler, Secretaris Pittsburgh, PA, USA Brussels, Belgium
Minesh P. Mehta Madison, WI, USA
Neurosurgery Medical Physics
Seiji Fukuoka Frank J. Bova Sapporo, Japan Gainesville, FL, USA
Roberto Martinez Ingmar Lax Madrid, Spain Stockholm, Sweden
Jean Régis, President Marseille, France 10 ISRS 2005 Committees & Organisers
Scientific Secretariat
Local Organising Committee Scientific Committee
Professor Marc Levivier Professor Jean Régis Chair of the Congress Chairman of the Scientific Committee U.L.B. - Hôpital Erasme Service de Neurochirurgie Neurosurgery and Gamma Knife Center Fonctionnelle et Stéréotaxique c/o ISRS 2005 Hôpital d'adulte de la Timone 808, route de Lennik 264 bvd Saint Pierre 1070 Brussels, Belgium 13385 Marseille Cedex 05, France Phone: +32 (0) 2/555 82 50 Phone: +33 (0) 4/91 38 65 62 Fax: +32 (0) 2/555 82 51 Fax: +33 (0) 4/91 38 70 56 E-mail: [email protected] E-mail: [email protected]
Professional Congress Organiser
The official Professional Congress Organiser (PCO) appointed by the local organising committee of the ISRS 2005 to ensure the successful efficient administration of all nonscientific aspects of the congress is:
ICEO International Congress and Event Organisers 122 avenue de l'Atlantique 1150 Brussels, Belgium Phone: +32 (0) 2/779 59 59 Fax: +32 (0) 2/779 59 60 E-mail: [email protected] & [email protected] Website: www.iceo.be
You can find the team members of ICEO at the registration desks at the ground floor or in the congress venue (light blue lanyards & badge), they will be pleased to help you !
11 The ISRS Society
About the ISRS The International Stereotactic Radiosurgery Society was founded in 1991. It was organized to promote the development of the field of stereotactic radiosurgery as follows: • by encouraging mutual fellowship, goodwill and scientific collaboration between all physicians and scientists actively involved in the field of stereotactic radiosurgery; • by elevating and sustaining the education of all involved in radiosurgery; • by establishing and promoting high standards for the treatment of patients with radio- surgery; • and by encouraging the accurate reporting of the results of radiosurgery. Members of the International Stereotactic Radiosurgery Society - mostly neurosurgeons, radiation oncologists and medical physicists - convene every two years to share clinical and scientific progress in radiosurgery.
Visit our website : www.intlsrs.org
Officers Douglas Kondziolka Robert Smee Roberto Spiegelmann President Vice-President Treasurer USA Australia Israel Board Members Rita Engenhart-Cabillic, MD David Larson, MD, PhD John Buatti, MD Mike McDermott, MD Frank Bova, PhD Masaaki Yamamoto, MD John Sun, MD ISRS Congress 2007 The 2007 ISRS Congress, the 8th anniversary of the biennial congress, will be held in San Francisco, USA. This congress will include not to be missed scientific sessions and posters on all aspects in the field of stereotactic radiosurgery. There will be extensive exhibits as well as opportunities for meeting colleagues and experts from the world at large. San Francisco is considered by many to be the most beautiful and interesting of American cities. Plan now to be a part of this hallmark event ! More information will be available soon on the ISRS website www.intlsrs.org
ISRS Board Meeting Tuesday Sept. 12, 2005, 12h30-14h00, meeting room Mezzo (1st floor)
ISRS Business Meeting (for Society members only) Wednesday Sept. 13, 2005, 17h30-18h00, room Nation (2nd floor) 12 Registration Information
Registration Desks
The team will be pleased to help you with all queries regarding registration, congress mate- rials, hotel bookings, social arrangements, congress program and excursions. Do not hesitate if there is any way in which we can make your stay more enjoyable.
Location Ground Floor of the Sheraton hotel
Opening hours Sunday Sept. 11, 2005 11h00 - 17h00 Monday Sept. 12, 2005 07h00 - 18h00 Tuesday Sept. 13, 2005 07h00 - 13h00 Wednesday Sept. 14, 2005 07h00 - 18h00 Thursday Sept. 15, 2005 07h00 - 14h00
Services desks available
Pre-registered For participants (members, non-members, one-day, scientific presenters, students, session chairs & accompanying persons) who have already registered at the congress and paid their registration fee.
Payments & on-site registration For all type of participants who register and pay their registration fee on-site, for partici- pants already registered who still have a balance to settle.
Sponsors & exhibitors For sponsors and exhibitors (company staff members).
Hotels, social events & tours • For any hotel information through the congress organiser ICEO (bookings made in advance or on-site requests - subject to availability). • For tours through the congress organiser ICEO (bookings made in advance or on-site requests - subject to availability). • For any information in relation to the official congress social events (bookings made in advance or on-site requests - subject to availability). Payments for these activities will be performed from the payment & on-site registration desk.
Press For journalists, registrations, press material or any other related information.
Tourist information A representative of the Brussels tourist office is available for any question you may have about your host city. 13 Registration Information
On-site Registration
On-site registration will start on Sunday September 11th, 2005.
0n-site registration fees Type of participants or event Fees Members 600 Non-members 700 Medical students and assistants 300 Accompanying persons 100 One-day registration 250 Exhibitors 350 Gala dinner 90 The above fees are in EURO (E), Belgian VAT (21%) included.
Payments Payments are accepted only in EURO (E), by credit cards (Visa, Master/Eurocard and American Express, exclusively) or cash. Checks, personal checks or money orders are not accepted.
Specific requirements Students and assistants Fee available for medical students and assistants up to 28 years old at the time of congress. Document from department head to certify student status as well as a copy of the ID card with the complete registration form are required.
Non members If you are not listed on the ISRS membership list, the organisers reserve the right to apply the non-member registration fee.
14 Registration Information
Registration Fees Include a a a a (one day) (one day) (one day) (one day) (one day) (one day) (one day) One-day registrants a a a a a a a a a a a a a a persons Accompanying availability availability a a a a a a a a Exhibitors Upon Upon a a a a a a a a a a a a a a Members, and assistants non-members, medical students . ednesday ednesday ve social events and tours ternoon coffee breaks on Monday and W ossibility to reser articipation and admission to the scientific sessions P Congress bag and congress documentation Badge Final program and abstracts book Morning coffee breaks on 4 days Af Sponsored lunches on Monday and W Opening ceremony & walking reception Access to the posters sessions & areas Access to the exhibition Certificate of attendance P For on-site registrations, exhibitors and one-day registration the full congress documentation, final program & book of abstracts and the congress bags are subject to availability 15 Congress Information & Services
Book of Abstracts The abstracts are printed and listed in this final program. They are also available on-line through the website www.isrs2005.com.
Accreditation The ISRS Congress 2005 has applied for Belgian accreditation from INAMI/RIZIV (Institut national d'assurance maladie-invalidité / Rijksfonds voor verzekering tegen ziekte en inva- liditeit) to establish the congress as a Belgian CME activity. For more information regarding the credits, please contact the scientific secretariat at the slide center.
Awards Fabrikant, Young Neurosurgeon and Best Poster Awardees will be recognized and celebrated during the closing session, planned on Thursday September 15, 2005 at 12h30.
Badges Name badges are used as passes. Admission into the congress venue (slide center, whole 2nd and 3rd floors) is strictly restricted to registered participants wearing their badge. You are also kindly requested to wear your badge during the official congress social events. Exhibitors and accompanying persons are not entitled to enter in the conference rooms. If the badge is lost, please go to the registration desk. Lost badges can be replaced at a cost of 10 E per badge. The following badge colors are used at the congress : Transparent: Delegates (members, non-members, on-site, students) White: Accompanying persons Yellow: One day Red: Scientific presenters (oral and posters) Blue: Sponsors and exhibitors Black: Staff and organisers
Bags Contents The congress bag for delegates includes: the final program and book of abstracts, a notepad, a pen, documentation from the congress major sponsors, companies bag inserts, a city map and documentation about Brussels. 16 Congress Information & Services
The documentation for accompanying persons includes: touristic information, map of Brussels, a notepad and documentation about the social program and the tours. Please note that for on-site registrations, one-day registration and exhibitors, there is no guarantee of availability of the full congress documents and bags.
Cancellation A refund of the registration fee will be given after the congress minus a 20% administrative charge, provided that a written notification has been sent to the organising secretariat no later than 30th June 2005. No refunds will be given for cancellations after June 30th, 2005. Reimbursements will be made after the congress.
Catering Registered delegates have free access to the congress catering area organized, in the exhi- bition (2nd floor).
Coffee breaks 10h00-10h30 Monday Sept. 12, 2005 Tuesday Sept. 13, 2005 Wednesday Sept. 14, 2005 Thursday Sept. 15, 2005 16h00-16h30 Monday Sept. 12, 2005 Wednesday Sept. 14, 2005
Lunches 12h30-14h00 Monday Sept. 12, 2005 Wednesday Sept. 14, 2005
Certificates of Attendance Certificates of attendance can be collected at the registration desks as of Wednesday September 14, 2005 (during the desks opening hours).
Cloakroom A cloakroom is at your disposal on the 2nd floor during the congress opening hours. Please note that the organisers of the ISRS 2005 congress deny any responsibility in case of losses and/or theft. 17 Congress Information & Services
Disabled Persons Lifts can be used by participants to access all floors of the Sheraton hotel. For special requests, please contact the team at your disposal at the registration desks.
Display Areas Display areas are situated on the ground floor and on the 2nd floor.
Disclaimer The ISRS 2005 congress and/or its agent have the right for any reason beyond their control to alter or cancel, without prior notice, the congress or any of the arrangements, timetables, plans or other items relating directly or indirectly to the congress. ISRS 2005 congress and or its agent shall not, subject as after-mentioned, be liable for any loss, damage, expenditure or inconvenience caused as a result of such alternation or can- cellation.
Dress Code The dress code during the congress is business casual. The gala dinner dress code is business attire.
First Aid For any medical assistance or emergency service, please contact immediately the registra- tion desks (ground floor).
Hotels Most of the participants to the ISRS 2005 congress are accommodated in hotels near the congress venue in the center of the city. For further information regarding your hotel boo- king or availabilities, please come at the hotels, social events & tours desk (ground floor).
Internet Area & Wi-fi The ISRS 2005 internet area is at your disposal on the left side of exhibition entrance (2nd floor). To avoid long lines or waiting time, users are kindly required to limit the use of the work- station to 15 minutes per connection. 18 Congress Information & Services
In the Sheraton hotel, Wi-fi services cover the first floor as well as the restaurant of the hotel. More information regarding Wi-fi services is available from the Sheraton hotel receptions.
Language The official language of the ISRS 2005 congress is English. No simultaneous translation is provided in the conference rooms.
Lost and Found For lost and/or found items, please contact the registration desk (ground floor).
Lottery As published on the website at the time of the second announcement, delegates who have been visiting and registering on the website, www.isrs2005.com, before 31 March 2005, have a chance of being reimbursed of their registration fee. The winner drawing will be organized on Thursday September 14, 2005 during the closing session. The winner will be informed through the message board (2nd floor) on the same day as well as by email.
Meeting Rooms The ISRS 2005 congress scientific sessions and all related activities are exclusively held in the meeting rooms of the Sheraton Hotel. The sessions are organized in the following meeting rooms : Plenary sessions Nation (2nd floor) Oral sessions Nation (2nd floor) Permeke - Rembrandt (3rd floor) Willumsem (3rd floor) Breakfast seminars Rembrandt (3rd floor) Permeke (3rd floor) Willumsem (3rd floor) Poster sessions Holbein (3rd floor) Turner (3rd floor) Foyer (3rd floor) See maps on the inside front cover for the exact location of these meeting rooms. Wireless microphones are at your disposal in each meeting room. Participants wishing to take part in discussions should raise their hand to be acknowledged by the chairs of the session and go to the nearest microphone. Cellular phones should be switched off and video or tape recording is not permitted. 19 Congress Information & Services
Meeting Point The ISRS 2005 Congress meeting point is situated in the registration area (ground floor).
Messages Delegates have the opportunity to let messages to other participants at the message board on the 2nd floor, near the lift and stairs. You can pick up your message there.
Parking The Sheraton does not have a private parking. The nearest underground parkings are the Rogier parking or the Manhattan parkings (same building as the congress venue). The Manhattan Parking is open 24h/24h. For one hour the fare is 2 E. The whole day at the ISRS Congress, which is around 10 hours, will cost you around 13,50 E. The Rogier parking is open from Monday to Saturday form 7h00 to 23h30, closed on Sunday. For one hour the fare is 2,10 E. Between 9h00 and 24h00 parking time, the price is 13,80 E. Both parkings are equipped with automatic cash machine and credit card facilities. Also, many public parkings can be found in the surroundings.
Personal Insurance All participants should carry the proper travel and health insurance. The ISRS 2005 congress cannot accept liability for any accidents or injuries that may occur at the congress.
Photocopy & Fax A business center, where you can make photocopies and send fax is situated in front of the hotel reception desk (ground floor).
Press Pre-registered or on-site registrant journalists are invited to go at the press desk (ground floor) to collect the press materials. A press conference is organized at the congress venue on Thursday September 15, 2005. More information is available from the press desk.
20 Congress Information & Services
Security Access within the congress floors during the congress hours is controlled by the security of the ISRS 2005 Congress and it is limited to the participants wearing the congress badges. The Sheraton surveillance agents will ensure the general security of the hotel’s guests. The exhibition area will be locked during the night. Every reasonable precaution is taken in terms of safety and security. However, as in all major cities and public areas, people should take special care of their personal belongings. The responsibilities of the ISRS 2005 are limited.
Smoking For health and security reasons and as a courtesy to non-smoking participants, you are not allowed to smoke on the 2nd and 3rd floor of the Sheraton Hotel, as well as in the restaurant of the hotel. However the hotel lobby on the ground floor remains a smoking area.
Special Needs For any special needs or dietary requests please contact the on-site registration desks (ground floor). Special requirements for vegetarians or other diets can be arranged upon request.
Vouchers Vouchers for pre-registered delegates to the gala dinner or tours are distributed together with their badge.
21 Scientific Program
Introduction
The day by day scientific program is organized along calendar days in the following pages. The overview chart is on the inside back cover, at the beginning of this program. This detailed day by day program contains all information regarding day, time, session type, session number, meeting room, session title, chairmen, speakers and abstracts titles.
The book of abstracts is published at the end of this final program. It includes accepted papers, listed in the chronological order of their presentation.
Numbering of abstracts The abstracts have been numbered by session. Poster session abstracts have been grouped according to the poster session to which they relate.
Scientific Sessions Descriptions
BS / Breakfast seminars Parallel breakfast seminars are taking place on the 3rd floor, in the rooms Permeke, Rembrandt and Willumsen on : Monday Sept. 12, 2005 07h30 - 08h30 Tuesday Sept. 13, 2005 07h30 - 08h30 Wednesday Sept. 14, 2005 07h30 - 08h30 Thursday Sept. 15, 2005 07h30 - 08h30 A light continental breakfast is served in the respective meeting rooms to the attendees of these sessions.
PS / Plenary sessions Plenary sessions are all organized on the 2nd floor, in the meeting room Nation. They last 1h15 and are held by renowned experts on : Monday Sept. 12, 2005 08h45 - 10h00 Tuesday Sept. 13, 2005 08h45 - 10h00 Wednesday Sept. 14, 2005 08h45 - 10h00 Thursday Sept. 15, 2005 08h45 - 10h00
OS / Oral Sessions Oral sessions are located on the 2nd and 3rd floor, in the rooms Nation, Permeke, Rembrandt and Willumsen and will take place on : Monday Sept. 12, 2005 11h30 - 12h30 14h00 - 15h00 15h00 - 16h00 16h30 - 17h30 22 Scientific Program
Tuesday Sept. 13, 2005 10h30 - 11h30 11h30 - 12h30 Wednesday Sept. 14, 2005 11h30 - 12h30 14h00 - 15h00 15h00 - 16h00 16h30 - 17h30 Thursday Sept. 15, 2005 10h30 - 11h30 11h30 - 12h30
Poster Viewing Posters are displayed on the 3rd floor, in the rooms Turner, Holbein and Foyer as follows : Monday Sept. 12, 2005 10h00 - 17h30 Poster Session P1 Tuesday Sept. 13, 2005 10h00 - 12h30 Poster Session P1 Wednesday Sept. 14, 2005 10h00 - 17h30 Poster Session P2 Thursday Sept. 15, 2005 10h00 - 12h30 Poster Session P2
P / Poster Sessions During the following sessions organized in the poster areas on the third floor, you are able to meet the authors of the posters as well as some of the co-authors. A poster board with a position number for identification purposes is at the entrance of the poster rooms. Moreover, an ICEO team member will be there to assist you. P1 Monday Sept. 12, 2005 10h30 - 11h30 Topics: GENERAL, EXTRACRANIAL RADIOSURGERY, VESTIBULAR SCHWANNOMAS, ARTERIOVENOUS MALFORMATIONS, METASTASES, GLIOMAS, RADIOBIOLOGY, MEDICAL IMAGING, PROTON THERAPY
P2 Wednesday Sept. 14, 2005 10h30 - 11h30 Topics: PHYSICS, MOLECULAR IMAGING, MENINGIOMAS, FUNCTIONAL, RADIOSURGERY, SPINAL RADIOSURGERY, PITUITARY TUMORS
Slide Center & Oral Presenters Guidelines
Slide center opening hours Sunday Sept. 11, 2005 14h00 - 18h00 Monday Sept. 12, 2005 07h00 - 17h30 Tuesday Sept. 13, 2005 07h00 - 12h30 Wednesday Sept. 14, 2005 07h00 - 17h30 Thursday Sept. 15, 2005 07h00 - 12h30
23 Scientific Program
Location The slide center is located on the 1st floor, room Tempo for the arrangement and preview of presentations. A representative of the scientific secretariat will also be at your disposal in this room.
Guidelines All presentations should be downloaded at the slide center for distribution to the conference rooms. It is not allowed to bring your presentations directly to the technical assistants in the meeting rooms. Speakers are requested to be present in their presentation room 10 minutes before the start of the session. The presentations run with PowerPoint only. The technical equipment and software in the Slide Center is both PC and MAC compatible. In order to avoid any delay, speakers are kindly requested to hand in their presentation on an electronic support (CD-ROM, USB key, DVD, zip disc, floppy disk or folder) at the slide center at least two hours prior to their session. If your session starts early in the morning, please bring the presentation by 17h30 the day before (by 12h30 on Tuesday if your ses- sion is on Wednesday). If you have any questions, please contact the team of technicians at your disposal in the pre- view room.
Equipment in the meeting rooms All meeting rooms are equipped with a data projector and a computer. A technician is planned in each meeting room. Speakers do not need to bring their own laptop.
Poster Presenters Guidelines
At least one of the authors must be present during the entire poster session for which you are scheduled. We encourage you to come with many of your co-authors.
Awards During all poster sessions the scientific committee members will circulate and discuss poster subjects in order to select candidates for Poster Awards. Be prepared to discuss all aspects of your work.
Size and font The poster should be no larger than 90 cm (wide) by 150 cm (tall). As a courtesy to all poster presenters we ask the poster presenter to respect this size limit. A font size that is easily readable from a distance of up to two meters should be used. 24 Scientific Program
Posters setup Posters must be mounted on the first day of your presentation (according to the topic), between 07h30 and 09h30 in the morning. They must remain displayed until the end of your poster session (the 2nd day). Presenters should ensure that the poster is displayed on the correct poster board, according to the position number communicated. Please note that the provided stickers are the only method of mounting allowed in order not to damage the panels. Any damage will be charged to the poster presenter/author. Nothing should be written or painted on the poster boards.
Poster presenter help desk During the mantling time, an ICEO team member will be there to assist you with your poster board position and to provide you with poster stickers.
Dismantling The presenters are requested to take the poster down at the end of the 2nd day of their poster presentation. If the poster is not removed by the end of the poster viewing slots it will be taken down by the congress staff. The congress cannot accept liability for lost and damaged posters.
Disclaimer & Guest Editor
Disclaimer on the published scientific information This program and book of abstracts have been produced using the author-supplied copy, received by August 27, 2005. Every effort has been made to faithfully reproduce the abstracts as submitted. Editing has been restricted to some corrections of spelling and style where appropriate. ISRS 2005 assume no responsibility for any claims, instructions, methods or information con- tained in the abstracts and title: it is recommended that these are verified independently. Subscription cancellations may have been received after the publishing date. Therefore, some change may occur in the scientific program, on-site, or in the posters numbering. Missing numbers indicate abstracts either not submitted in time for publication, or those subsequently withdrawn.
Guest editor and contact The scientific program and book of abstracts have been organized and edited by the President and Secretaris of the scientific committee, Prof. Jean Regis and Ir. David Wikler, respectively . For any inquiries regarding published scientific information or for any other questions that arise after acceptance of a paper, please contact them by e-mail or inquire the scientific desk at the time of the congress, located in the speakers slide center. 25 Scientific Program Sunday 11/09/05 Daily Scientific Program
Sunday 11/09/05
PRE-CONGRESS SYMPOSIUM & LUNCH * 12h30 - 16h30
Organized by Accuray Room PIONEERING TECHNIQUES IN CYBERKNIFE RADIOSURGERY Permeke & Rembrandt Chairmen: Marc, Levivier; Berndt, Wowra; Peter, Levendag
Technology Innovations for Accurate Full Body Radiosurgery
Intracranial Indications
Spinal Indications
Soft Tissue Indications
Special welcome desk organized from 12h00 (distribution of the complete program of the session and bagdes)
Lunch planned for all attendees in the meeting room, from 12h30
* registration required
OPENING CEREMONY 17h00 - 18h00
THE EU COMPETITIVENESS AND THE SOCIO-ECONOMIC Room Nation CHALLENGES OF RADIOSURGERY Special guest speaker: Philippe Busquin (European Deputy and former Commissioner for Research at the European Commission)
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Monday 12/09/05 12/09/05 Monday
Breakfast seminars 7h30 - 8h30
FRAMELESS STRATEGIES BS1 Room Rembrandt
Frame-based versus frameless strategies BS1-1 Ingmar, Lax
Frame-based versus frameless radiosurgery : accuracy issues BS1-2 David, Wikler
Novalis system – What future for frameless strategies? BS1-3 Antonio, DeSalles
COMBINED APPROACHES BS2 Room Permeke
Combined strategies for large skull base meningiomas BS2-1 Seiji, Fukuoka
Rationale for combined micro- and radio-surgical approaches BS2-2 in the management of vestibular schwannomas and skull base meningiomas Pierre-Hugues, Roche
Neurosurgical image guidance in partial tumor removal BS2-3 for radiosurgery Marc, Levivier
RADIOSURGICAL PATHOLOGY OF BRAIN TUMORS BS3 AND EXPERIMENTAL BACKGROUND Room Willumsen
Radiosurgery: is it an immune stimulating weapon BS3-1 in brain tumor neurosurgery? Gyorgy, Szeifert
How do brain tumors respond to radiosurgery? BS3-2 Dave S, Atteberry
Brain vascular changes induced by radiosurgery in a rat model BS3-3 José, Lorenzoni 27 Scientific Program
PLENARY SESSION 8h45 - 10h00
CONFORMITY & SELECTIVITY, LUNG CANCER, PS1 CRANIOPHARYNGIOMAS, SPINAL METASTASES Room Nation Chairman: Marc, Levivier Monday 12/09/05 Enhanced conformality and selectivity using robotic radiosurgery PS1-1 L. Dade, Lunsford (1); Douglas, Kondziolka (1); Ajay, Niranjan (2); John C, Flickinger (1); Ann H., Maitz (3) (1) University of Pittsburgh Medical Center - Department of Neurological Surgery; (2) University of Pittsburgh Medical Center - Neurological Surgery; (3) University of Pittsburgh Medical Center - Image Guided Neurosurgery Pittsburgh, USA
Stereotactic radiotherapy for patients with inoperable PS1-2 early stage lung cancer. A retrospective study Pia, Baumann (1); Lars, Ekberg (2); Ulf, Isaksson (3); Karl-Axel, Johansson (4); Ingmar, Lax (1); Rolf, Lewensohn (1); Jan, Nyman (4); Suzanne, Rehn-Eriksson (5); Lena, Wittgren (2); Signe, Friesland (1) (1) Karolinska Institutet - Department of Oncology; (2) Malmö University Hospital - Department of Oncology and Hospital Physics; (3) Karolinska Institutet - Department of Neurosurgery; (4) Sahlgrenska University Hospital - Departments of Hospital Physics and Oncology; (5) Uppsala University Hospital - Departments of Hospital Physics and Oncology Stockholm, Sweden
Quality of life after stereotactic radiotherapy for stage I PS1-3 non-small cell lung cancer (NSCLC) Frank J., Lagerwaard (1); Ylanga G., van der Geld (1); Ben J., Slotman (1); Suresh, Senan (1) (1) VU Medical Center Amsterdam - Department of Radiation Oncology Amsterdam, The Netherlands
Role of radiosurgery in the multimodality management PS1-4 of craniopharyngiomas Ajay, Niranjan (1); Pramod Kumar, Pillai (2); L. Dade, Lunsford (3); Douglas, Kondziolka (3); John C, Flickinger (3) (1) University of Pittsburgh Medical Center - Neurological Surgery; (2) University of Pittsburgh Medical Center - Neurological Surgery; (3) University of Pittsburgh Medical Center - Department of Neurological Surgery Pittsburgh, USA
Image-Guided radiosurgery of single spinal metastasis PS1-5 Samuel, Ryu (1); Jack, Rock (2); Jian-Yue, Jin (3); Marilyn, Gates (2); Benjamin, Movsas (4); Jae Ho, Kim (5) (1) Henry Ford Hospital - Radiation Oncology; (2) Henry Ford Hospital - Neurosurgery; (3) Henry Ford Hospital - Radiation Oncology; (4) Henry Ford Hospital - Radiation Oncology; (5) Henry Ford Hospital - Division of Radiation Oncology Detroit, USA
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POSTER SESSION 10h30 - 11h30 12/09/05 Monday GENERAL, EXTRACRANIAL RADIOSURGERY, P1 VESTIBULAR SCHWANNOMAS, ARTERIOVENOUS Room Holbein, MALFORMATIONS, METASTASES, GLIOMAS, Turner & Foyer RADIOBIOLOGY, MEDICAL IMAGING, PROTON THERAPY
Clinical and radiobiological advantages of stereotactic light ion beam radiation therapy for large intracranial arteriovenous malformations P1-1 Bahram, Andisheh (1); Bengt, Lind (1); Mohammadali, Bitaraf (2); Panayiotis, Mavroidis (1); Anders, Brahme (1) (1) Karolinska Institutet - Department of Medical Radiation Physics; (2) Iran Medical Science Of University, Ali Asghar Hospital - Iran Gamma Knife Center Stockholm, Sweden
Gamma knife radiosurgery for cerebral arteriovenous malformation P1-2 Maheep Singh, Gaur (1) (1) VIMHANS Complex - Department of Gamma Knife Radiosurgery New Delhi, India
Management and outcomes of hemorrhage for cerebral arteriovenous malformations treated with radiosurgery P1-3 Tomoyuki, Kouga (1); Keisuke, Maruyama (1); Masahiro, Shin (1); Hiroki, Kurita (2); Nobutaka, Kawahara (1); Akio, Morita (1); Takaaki, Kirino (1) (1) University of Tokyo Hospital - Department of Neurosurgery; (2) Kyorin University Hospital - Department of Neurosurgery Tokyo, Japan
Follow-up to cure of intracranial arteriovenous malformations after gamma knife radiosurgery P1-4 Michael, Musacchio (1); Brian, Kuchay (1); Nimesh, Patel (1); Sepehr, Sani (1); Demetrius, Lopes (1) (1) Rush University Medical Center - Neurosurgery Chicago, USA
Fractionated stereotactic radiosurgery for large intracranial arteriovenous malformations P1-5 Shaan, Raza (1); Quoc-Anh, Thai (1); Salma, Jabbour (2); Gustavo, Pradilla (1); Lawrence, Kleinberg (3); Moody, Wharam (3); Daniele, Rigamonti (1) (1) Johns Hopkins University School of Medicine - Department of Neurosurgery; (2) The Johns Hopkins University School of Medicine - Department of Radiation Oncology and Molecular Radiation Sciences Baltimore, USA
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Fractionated stereotactic radiotherapy in residual or recurrent nasopharyngeal carcinoma P1-6 Mantana, Dhanachai (1); Puangtong, Kraiphibul (1); Lucksana, Pochanugool (1); Somjai, Dangprasert (1); Putipun, Puataweepong (1); Ladawan, Narkwong (1); Jiraporn, Laothamatas (1); Boonchu, Kulapraditharom (2); Veerasak, Theerapancharoen (3); Ekaphop, Sirachainan (4); Pornpan, Yongvithisatid (1); Prasert, Assavaprathuangkul (1) Monday 12/09/05 (1) Ramathibodi Hospital Mahidol University - Department of Radiology; (2) Ramathibodi Hospital Mahidol University - ENT; (3) Ramathibodi Hospital Mahidol University - Department of Surgery; (4) Ramathibodi Hospital Mahidol University - Medicine Bangkok, Thailand
Linac radiosurgery in extracerebral head and neck lesions P1-7 Miron, Sramka (1); Augustin, Durkovsky (2); Arpad, Viola (3); Yaroslav, Parpaley (1); Peter, Strmen (4) (1) St. Elisabeth Cancer Institute - Department of Radiosurgery; (2) St. Elisabeth Cancer Institute - Department of Radiology; (3) St. John's Hospital Budapest, Hungary - Department of Neurosurgery; (4) Comenius University hospital - Department of ophtalmology Bratislava, Slovakia
Endocavitary irradiation of glioma cysts with 90-Yttrium colloid solution P1-9 Arpad, Viola (1); Jeno, Julow (1); Balint, Katalin (2); Istvan, Nyary (3) (1) St. John's Hospital Budapest, Hungary - Department of Neurosurgery; (2) National Institute of Neurosurgery, Budapest, Hungary - Department of Pathology; (3) National Institute of Neurosurgery, Budapest, Hungary - Department of Neurosurgery Budapest, Hungary
Specific nurse attendance during routine Leksell Gama Knife radiosurgery in children P1-10 Elisabeth, Rioz Galvez (1); Benoit, Pirotte (2); Patricia, Palacio (1); Arlette, Dewil (1); Philippe, David (3); Daniel, Devriendt (4); Françoise, Desmedt (5); Michel, Baurain (6); Jacques, Brotchi (2); Marc, Levivier (7) (1) Hôpital Erasme - Centre Gamme Knife; (2) Hôpital Erasme - Neurochirurgie; (3) Hôpital Erasme - Neuroradiologie; (4) Institut J. Bordet - Radiothérapie; (5) Hôpital Erasme - Centre Gamme Knife; (6) Hôpital Erasme - Anaesthesiology Brussels, Belgium
Gamma knife radiosurgery in pediatric population. Early Mexican experience P1-11 Daniel Salvador, Ruiz Gonzalez (1); Ramiro, Del Valle (1); Salvador, De Anda Ponce de Leon (1); Miguel, Perez Pastenes (1); Juan, Ortiz Retana (1); Manuel, Martinez Lopez (1); Josue, Estrada (1) (1) Medica Sur SA de CV MSU 820125 T58 - Unidad Gamma Knife Mexico, Mexico
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Stereotactic radiosurgery for benign brain tumors 12/09/05
- A single institution experience P1-12 Monday George, Pissakas (1); V, Georgolopoulou (2); M, Kalogeridou (3); E, Andriotis (4); K, Doukaki (3); S, Kosmidou (3); S, Mourgela (5); G, Arhontakis (7); E, Pappas (2); V, Kouloulias (6); I, Kouvaris (10); A, Sotiropoulou (3) (1) ALEXANDRA Athens General Hospital - Radiation Oncology; (2) St.Savvas Hospital - Medical Physics; (3) St.Savvas Hospital - Radiation Oncology; (4) St.Savvas Hospital - Radiology; (5) St.Savvas Hospital - Neurosurgery; (6) University of Athens - Radiation Oncology Athens, Greece
Gamma knife radiosurgery for skull base tumors - Complications and outcome P1-13 Sujoy, Sanyal (1); Sandeep, Vaishya (2); Aditya, Gupta (2); S S, Kale (2); V S, Mehta (2) (1) All India Institute of Medical Sciences - Neurosurgery Department; (2) All India Institute of Medical Sciences - Neurosurgery Department Calcutta, India
Image guided micro radiosurgery for brain tumors to avoid underlining dysfunction of the surrounding vital structure: technical note P1-16 Motohiro, Hayashi (1); Jean, Regis (2); Taku, Ochiai (1); Koutaro, Nakaya (1); Mikhail, Chernov (1); Masahiro, Izawa (1); Tomokatsu, Hori (1); Kintomo, Takakura (1) (1) Tokyo Women's Medical University - Department of Neurosurgery; (2) CHU La Timone - Service de Neurochirurgie Tokyo, Japan
Preliminary experience with MMLC at the INNN in Mexico City. 804 patients treated in a singular facility P1-17 Miguel Angel, Celis-Lopez (1); Jose, Suarez-Campos (1); Sergio, Moreno (1); Leopoldo, Herrera (1); Jose M, Larraga (1); Amanda, Garcia G (1); Mariana, Hernandez B (1) (1) National Institute of Neurology and Neurosurgery - Radioneurosurgery Mexico City, Mexico
The use of tissue equivalent Super Stuff Bolus (TM) material to treat skull metastases with gamma knife radiosurgery P1-18 Lilyana, Angelov (1); Gennady, Neyman (2); Gene H, Barnett (3); Betty, Jamison (4); John H., Suh (5); Lilyana, Angelov (6) (1) Cleveland Clinic Foundation - Department of Neurosurgery; (2) Cleveland Clinic Foundation - Department of Radiation Oncology; (3) Cleveland Clinic Foundation - Brain Tumor Institute; (4) Cleveland Clinic Foundation - Brain Tumor Institute; (5) Cleveland Clinic Foundation - Gamma Knife Center; (6) Cleveland Clinic Foundation - Brain Tumor Institute Cleveland, USA
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Magnetic resonance image distortion: a phantom study with varying parameters for stereotactic radiosurgery P1-19 Sawwanee, Asavaphatiboon (1); Ladawan, Worapruekjaru (2); Jiraporn, Laothamatas (2); Pornpan, Yongvithisatid (2); Wiboon, Suriyajakyuthana (2); Lojana, Tuntiyatorn (2); Mantana, Dhanachai (2) (1) Ramathibodi Hospital Mahidol University - Radiology; (2) Ramathibodi Hospital Mahidol University - Department of Radiology Monday 12/09/05 Bangkok, Thailand
The use of T2 weighted MRI for post gamma knife follow-ups P1-20 Joel Y. C., Cheung (1); C.P., Yu (1); Robert TK, Ho (1) (1) Canossa Hospital - Gamma Knife Centre Hong Kong, Hong Kong
Effects of fiducial marker defects in image registration P1-21 Hyun-Tai, Chung (1); Dong Gyu, Kim (1) (1) Seoul National University Hospital - Department of Neurosurgery Seoul, Republic of Korea
The impact of different ways of image definition on the z-position of the target P1-22 Andreas, Mack (1); Stefan, Scheib (2); Marcus, Rieker (3); Dirk, Weltz (4); Robert, Wolff (5); Hans-Jürg, Kreiner (6); Volker, Seifert (7); Heinz, D., Böttcher (8) (1) Gamma Knife Center Frankfurt - Medical Physics; (2) Klinik im Park - Medical Radiation Physics; (3) PTGR- GmbH - Software Development; (4) PTGR-GmbH - Software Development; (5) Gamma Knife Center Frankfurt - Neurosurgery; (6) GKS-GmbH - Management; (7) Johann Wolfgang Goethe University - Neurosurgery; (8) Johann Wolfgang Goethe University - Radiotherapy Frankfurt, Germany
Hypofractionated stereotactic radiotherapy for lung tumors P1-23 Antje, Ernst-Stecken (1); Ulrike, Lambrecht (1); Rolf, Sauer (1); Oliver, Ganslandt (1); Gerhard, Grabenbauer (1) (1) Novalis Shaped Beam Surgery Center, University Hospital of Erlangen, Germany - Radiation Oncology Erlangen, Germany
Dose escalation in the treatment of lung cancer with CyberKnife without increasing the dose to the organs at risk: a treatment planning study compared to 3-D radiotherapy P1-24 Jean-Briac, Prévost (1); Joost, Nuyttens (2); John, Praag (1) (1) Erasmus MC-Daniel den Hoed Cancer Center - Radiation Oncology; (2) Erasmus MC - Radiotherapy Rotterdam, The Netherlands
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The combined stereotactic procedures for cystic cerebral 12/09/05
metastatic tumors: A possible pitfall in ‘one day double Monday procedures’ P1-25 In-Young, Kim (1); Jung, Shin (2); Tae-Young, Jung (1); sam-Suk, Kang (1) (1) Chonnam University Medical School - Brain Tumor Clinic & Gamma Knife Center, Department of Neurosurgery; (2) Chonnam University Medical School - Department of Neurosurgery Kwangju, Republic of Korea
The benefit of Gama Knife radiosurgery in the treatment of thalamic and brainstem metastases P1-26 Wolfgang, Kreil (1); Verena, Weigl (1); Josef, Luggin (1); Sandro, Eustacchio (1); Georg, Papaefthymiou (1); Oskar, Schröttner (1) (1) Medical University Graz - Dept. of Neurosurgery Graz, Austria
Clinical impact of high-resolution MRI on stereotactic radiosurgery for patients with brain metastases P1-27 Julian, Perks (1); William, Hall (1); Conrad, Pappas (1); James, Boggan (2); Robin, Stern (1); John, Hartman (3); Claus, Yang (1); Richard, Latchaw (6); Allan, Chen (1) (1) U.C. Davis Cancer Center - Radiation Oncology; (2) U.C. Davis - Neurosurgery; (3) U.C. Davis - Radiology Sacramento, USA
Evaluation of prognostic factors in patients affected by brain metastases from lung cancer treated with gamma knife radiosurgery P1-28 Piero, Picozzi (1); Alberto, Franzin (2); Silvia, Snider (2); Francesca, Marchesi (3); Luca, Attuati (2); Antonella, Del Vecchio (1); Vanessa, Gregorc (4) (1) Ospedale San Raffaele - Stereotactic Neurosurgery & Gamma Knife Department; (2) Ospedale San Raffaele - Neurosurgery Department; (3) Ospedale San Raffaele - Department of Oncology Milano, Italy
Linac based sterotactic radiosurgery (SRS) of brain metasases - 10 years experience P1-29 Martin, Chorvath (1); Martina, Skoknova (2); Yaroslav, Parpaley (2); Augustin, Durkovsky (3); Miron, Sramka (2); Juraj, Steno (4); Elena, Boljesikova (1) (1) St. Elisabeth Cancer Institute - Department of Radiotherapy; (2) St. Elisabeth Cancer Institute - Department of Radiosurgery; (3) St. Elisabeth Cancer Institute - Department of Radiology; (4) Faculty Hospital of the Comenius University - Department of Neurosurgery Bratislava, Slovakia
Gamma knife radiosurgery for brain metastasis. Analysis of survival and prognostic factors P1-30 Alberto, Franzin (1); Piero, Picozzi (1); Silvia, Snider (2); Camillo, Ferrari Da Passano (1); Lorenzo, Gioia (1); Massimo, Giovanelli (1) (1) Ospedale San Raffaele - Neurosurgery Department; (2) Ospedale San Raffaele - Stereotactic Neurosurgery & Gamma Knife Department Milano, Italy 33 Scientific Program
Stereotactic drainage and gamma knife radiosurgery of cystic brain metastasis P1-31 Alberto, Franzin (1); Micol, Valle (1); Massimo, Giovanelli (1) (1) Ospedale San Raffaele - Neurosurgery Department Milano, Italy Monday 12/09/05 Recurrent metastases following whole brain irradiation: hope for patients in RPA class III? P1-32 Markus, Gross (1); Steffi, Pracht (2); Klaus, Hamm (2); Rita, Engenhart-Cabillic (3) (1) Philipps University Marburg - Department of Radiotherapy; (2) Helios-Kliniken Erfurt - Department of stereotactic Neurosurgery and Radiosurgery; (3) Philipps University Marburg - Radiotherapy and Radiooncology Department Marburg, Germany
Gamma knife radiosurgery for the cavernous sinus metastases and invasion P1-33 Yoshiyasu, Iwai (1); Kazuhiro, Yamanaka (1); Masaki, Yoshimura (1) (1) Osaka City General Hospital - Department of Neurosurgery Osaka, Japan
Fatal intratumoral hemorrhage immediately after gamma knife radiosurgery for brain metastasis: Case report P1-34 Masahiro, Izawa (1); Mikhail, Chernov (1); Motohiro, Hayashi (1); Yuichi, Kubota (1); Hidetoshi, Kasuya (1); Tomokatsu, Hori (1) (1) Tokyo Women's Medical Univeristy - Department of Neurosurgery Tokyo, Japan
Gamma knife radiosurgery for metastatic alveolar soft part sarcoma : a case report P1-35 Jang, Jae-Won (1); In-Young, Kim (1); Jung, Shin (2) (1) Chonnam University Medical School - Brain Tumor Clinic & Gamma Knife Center, Department of Neurosurgery; (2) Chonnam University Medical School - Department of Neurosurgery Kwangju, Republic of Korea
Radiosurgery for the treatment of brain stem metastases: relationship between clinical status and survival P1-36 José, Lorenzoni (1); Daniel, Devriendt (2); Nicolas, Massager (3); Françoise, Desmedt (1); Stéphane, Simon (4); Paul, Van Houtte (2); Jacques, Brotchi (3); Marc, Levivier (1) (1) Hôpital Erasme - Centre Gamme Knife; (2) Institut J. Bordet - Radiothérapie; (3) Hôpital Erasme - Neurochirurgie; (4) Institut J. Bordet - Physique Brussels, Belgium
Stereotactic irradiation (STI) boost for multiple brain metastases P1-37 Hisato, Nagano (1); Takashi, Shuto (2); Yuji, Nakayama (2); Inomori, Shigeo (2) (1) Yokohama Rosai Hospital - Radiationoncology; (2) Yokohama Rosai Hospital - Neurosugery Yokohama Kanagawa, Japan 34 Scientific Program
Localized therapy for limited metastatic disease to the brain: 12/09/05
A Phase II study of surgery, stereotactic radiosurgery (SRS) Monday and stereotactic radiotherapy (SRT) in favorable patients P1-38 Lucien, Nedzi (1); John Wilson, Walsh (2); Roy, Weiner (3); Bryan R., Payne (4); Ellen, Zakris (1); Robert, Sanford (5); Timothy, Pearman (6); Paul, Rosel (7); Raja, Mudad (3); Anna, Hall (8); Judy, Weber (9) (1) Tulane University - Radiation Oncology; (2) Tulane University Medical Center - Department of Neurosurgery; (3) Tulane University - Department of Hematology/Oncology; (4) LSU School of Medicine at New Orleans - Department of Neurosurgery; (5) Tulane University - Radiation Oncology; (6) Tulane University - Psychology; (7) Tulane University - Radiology; (8) Tulane University Hospital and Clinic - Radiation Oncology; (9) New Orleans Regional Gamma Knife Center - Nursing New Orleans, USA
Gamma knife (GK) radiosurgery for small brain metastases P1-39 Ouzi, Nissim (1); Daniel, Devriendt (2); Nicolas, Massager (3); Philippe, David (4); Françoise, Desmedt (1); Olivier, Coussaert (1); Stéphane, Simon (5); Paul, Van Houtte (2); Jacques, Brotchi (3); Marc, Levivier (1) (1) Hôpital Erasme - Centre Gamme Knife; (2) Institut J. Bordet - Radiothérapie; (3) Hôpital Erasme - Neurochirurgie; (4) Hôpital Erasme - Neuroradiologie; (5) Institut J. Bordet - Physique Brussels, Belgium
Fractionated gamma knife radiotherapy for huge metastatic tumor P1-40 Ushikubo, Osamu (1) (1) Kasai cardiology and neurosurgery hospital - neurosurgey Tokyo, Japan
Stereotactic radiosurgery boost for metastatic brain tumors receiving WBRT P1-41 George, Pissakas (1); V, Georgolopoulou (2); K, Doukaki (3); S, Mourgela (4); E, Andriotis (5); M, Kalogeridou (3); S, Kosmidou (3); G, Arhontakis (4); E, Pappas (2); I, Kouvaris (6); A, Sotiropoulou (3) (1) Alexandra Athens General Hospital - Radiation Oncology; (2) St.Savvas Hospital - Medical Physics; (3) St.Savvas Hospital - Radiation Oncology; (4) St.Savvas Hospital - Neurosurgery; (5) St.Savvas Hospital - Radiology; (6) University of Athens - Radiation Oncology Athens, Greece
Stereotactic irradiation for metastatic brain tumors from hepatocellular carcinoma P1-42 Masao, Tago (1); Kenshiro, Shiraishi (1); Keiichi, Nakagawa (1); Keisuke, Maruyama (2); Hiroki, Kurita (3); Masahiro, Shin (4); Atsuro, Terahara (4); Shunsuke, Kawamoto (5); Kuni, Ohtomo (1) (1) University of Tokyo Hospital - Department of Radiology; (2) University of Tokyo Hospital - Department of Neurosurgery; (3) Kyorin University Hospital - Department of Neurosurgery; (4) Toho University Omori Hospital - Department of Radiology; (5) Dokkyo University School of Medicine - Department of Neurosurgery Tokyo, Japan
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Radiosurgical treatment of “radioresistant” cerebral metastases P1-43 Charles, Valery (1) (1) Hopital de la Pitie-Salpetriere - Service de neurochirurgie Paris, France
Repeated in-situ recurrence of brain metastases after Monday 12/09/05 radiosurgery and resection: dural contact as a risk factor P1-44 Dirk, Van Den Berge (1); Guy, Soete (1); Christine, Collen (2); Recai, Ates (3); Katrijn, Van Rompaey (4); Jean, D'Haens (4); Guy, Storme (1) (1) AZ VUB - Radiothérapie; (2) AZ-VUB - Radiotherapy; (3) AZ VUB - Neurochirurgie Brussels, Belgium
Paradigm shift in management of patients with multiple brain metastases: From whole brain radiotherapy to gamma knife radiosurgery P1-45 Masaaki, Yamamoto (1); Bierta, Barfod (1); Yoichi, Urakawa (1) (1) Katsuta Hospital - Mita Gamma House Hitaxhi-Naka, Japan
Repeated radiosurgery for local recurrences of brain metastases after gamma knife radiosurgery P1-46 Kazuhiro, Yamanaka (1); Yoshiyasu, Iwai (1); Yasuhiro, Matsusaka (1); Kazuhito, Nakamura (1); Toshihiro, Yasui (1); Masaki, Komiyama (1) (1) Osaka City General Hospital - Department of Neurosurgery Osaka, Japan
Gamma knife radiosurgery for large volume brain metastases: Acceptable volume response rate with marginal increase in toxicity P1-47 C.P., Yu (1); Joel Y. C., Cheung (1); Josie F. K., Chan (2); Samuel, Leung (3); Robert TK, Ho (1) (1) Canossa Hospital - Gamma Knife Center; (2) Canossa Hospital - Gamma Knife Center; (3) Queen Elizabeth Hospital - Department of Neurosurgery Hong Kong, Hong Kong
A comparison of Whole Brain Radiation Therapy (WBRT) and radiosurgery (RS) for the treatment of brain metastases: If the volume is prognostic factor influencing survival ? P1-48 Edyta, Wolny (1); Aleksandra, Grzadiel (2); Andrzj, Tukiendorf (3); Leszek, Miscyk (1) (1) Center of Oncology-MSC Memorial Institute Branch in Gliwice - Radiotherapy Department; (2) Center of Oncology-MSC Memorial Institute Branch in Gliwice - Treatment Planning Department; (3) Technical University of Opole - Mechanical Faculty Gliwice, Poland
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Gamma knife radiosurgery for skull base chordomas: 12/09/05
What is an adequate dose level? P1-49 Monday Marc, Goldman (1); Georg, Noren (1); Stephen C., Saris (1); Carla, Bradford (1); Melissa, Remis (1) (1) Rhode Island Hospital, Brown University - New England Gamma Knife Center Providence, USA
Stereotactic radiosurgery in the management of glomus jugulare tumors P1-50 Francisco, Mascarenhas (1); A, Gonçalves Ferreira (2); H, Carvalho (3); M, Santos (4); A, Almeida (5); M, Vacas (6); M, Sá da Costa (7); S, Germano (8) (1) Hospital de Santa Maria- Lisboa-Portugal - Radiotherapy Dpt; (2) Hospital de Santa Maria- Lisboa-Portugal - Neurosurgery Dpt; (3) Hospital de Santa Maria- Lisboa-Portugal - Neurosurgery Dpt; (4) Hospital de Santa Maria- Lisboa-Portugal - Radiotherapy Dpt; (5) Hospital de Santa Maria- Lisboa-Portugal - Radiology Dpt; (6) Hospital de Santa Maria- Lisboa-Portugal - Neurosurgery Dpt; (7) Hospital de Santa Maria- Lisboa-Portugal - Radiotherapy Dpt; (8) Hospital de Santa Maria- Lisboa-Portugal - Radiotherapy Dpt Lisboa, Portugal
Dramatic short term response of tumors of the pineal region to the gamma knife radiosurgery P1-51 Mazdak, Alikhani (1); Mohammad Ali, Bitaraf (1) (1) Iran Medical Science Of University, Ali Asghar Hospital - Iran Gamma Knife Center Tehran, Iran
Cyberknife radiosurgery in recurrent head and neck cancer P1-52 Seong Yul, Yoo (1) (1) Radiation Oncology Department Seoul, South Korea
Radiosurgery for glomus jugulare: late results P1-53 Vladimir, Zaccariotti (1) (1) Association Against Cancer of Goias - Department of Neurosurgery Goias, Brazil
Early experience with a cyberknife stereotactic radiosurgical program P1-54 Michael, Schulder (1); Brian, Beyerl (1); Richard Hodosh (1); Edward, Zampella (1); Elsbieta, Masur (1); Louis Dchwartz (1) (1) New Jersey Medical School, Newark NJ, Overlook Hospital, Summit NJ Newark, USA
37 Scientific Program
Final design, integration and testing of the dedicated proton SRS/SRT beamline at the NPTC P1-55 Marc R, Bussiere (1); Isaac, Mendelson (1); Hanne, Kooy (1); Jay, Flanz (1); Miles, Wagner (1); Bernie, Gotchalk (2); Paul, Chapman (3); Jay, Loeffler (1) (1) Massachusetts General Hospital - Department of Radiation Oncology; (2) Harvard University - Physics Department; (3) Massachusetts General Hospital - Pediatric Neurosurgery Department Monday 12/09/05 Boston, USA
Three year radiosurgery experience at the Northeast Proton Therapy Center P1-56 Marc R, Bussiere (1); Hanne, Kooy (1); Paul, Chapman (2); Jay, Loeffler (1) (1) Massachusetts General Hospital - Department of Radiation Oncology; (2) Massachusetts General Hospital - Pediatric Neurosurgery Department Boston, USA
History of proton beam radiosurgery P1-57 Mehryar, Mashouf (1); Elham, Bidabadi (2) (1) Guilan university of medical sciences - Department of neurosurgery; (2) Guilan university of medical sci- ences - Pediatric neurology Rasht, IRAN
Radiosurgery damage probability in target volume. - A proposal for a biological response model P1-58 Vinicio, Toledo-Buenrostro (1); Gabriel, Rodriguez-Hernandez (2) (1) Hospital San Javier - Radiation Oncology; (2) Hospital San Javier - Medical Physics and Radiation Protection Guadalajara, Mexico
Distal region cephalothorax map of Crayfish Procambarus clarkii. Magnetic resonance atlas for experimental gamma radiosurgery P1-59 Daniel Salvador, Ruiz Gonzalez (1); Ramiro, Del Valle (1); Salvador, Ponce de Leon (1); M.P., Torres Garcia (2); J.L., Bortolini Rosales (3); Manuel, Martinez Lopez (1); L., Mendoza Vargas (4); E, Muñoz Mancilla (5); Miguel, Perez Pastenes (1); JA., Viccon Pale (7) (1) Medica Sur SA de CV MSU 820125 T58 - Unidad Gamma Knife; (2) University National of Mexico - Invertebrate Laboratory; (3) University National of Mexico - Invertebrate Laboratory; (4) Metropolitan Autonomous University. Mexico - Temporal Structures in Functional Crustaces Mexico, Mexico
38 Scientific Program
Distal region cephalothorax map of Crayfish Procambarus clarkii. 12/09/05
Cerebroid ganglion and adjacent structures histological map: Monday basic model for gamma radiosurgery P1-60 Ramiro, Del Valle (1); Daniel Salvador, Ruiz Gonzalez (1); Salvador, De Anda Ponce de Leon (1); Miguel, Perez Pastenes (1); M.P., Torres Garcia (2); J.L., Bortolini Rosales (3); E, Muñoz Mancilla (6); Manuel, Martinez Lopez (1); L., Mendoza Vargas (4); JA., Viccon Pale (9); Juan, Ortiz Retana (1) (1) Medica Sur SA de CV MSU 820125 T58 - Unidad Gamma Knife; (2) University National of Mexico - Invertebrate Laboratory; (3) University National of Mexico - Invertebrate Laboratory; (4) Metropolitan Autonomous University. Mexico - Temporal Structures in Functional Crustaces Mexico, Mexico
Modulation of dose rate effects to minimize normal neural tissue toxicity while maximizing tumor control probability P1-61 Steven, Howard (1); James, Welch (1); Ian, Robbins (2); Wolfgang, Tome (1) (1) University of Wisconsin Medical School - Human Oncology Department; (2) University of Wisconsin Medical School - Medical Oncology Madison, USA
Vascular changes in the rat middle cerebral artery after gamma knife irradiation (preliminary results) P1-62 José, Lorenzoni (1); Gyorgy, Szeifert (2); Isabelle, Salmon (3); Françoise, Desmedt (1); Jacques, Brotchi (4); Marc, Levivier (1) (1) Hôpital Erasme - Centre Gamme Knife; (2) National Institute of Neurosurgery - Department of Neurosurgery; (3) Hôpital Erasme - Department of Pathology; (4) Hôpital Erasme - Neurochirurgie Brussels, Belgium
Comparison of late radiobiological effect of the brachytherapy and LINAC radiosurgery modalities on the normal brain tissue P1-63 Arpad, Viola (1); Jeno, Julow (1); Tibor, Major (2) (1) St. John's Hospital Budapest, Hungary - Department of Neurosurgery; (2) National Institute of Oncology and Radiation Therapy, Budapest, Hungary - Department of Radiation Therapy Budapest, Hungary
Treatment of acoustic neurinoma with stereotactic radiosurgery P1-64 Leoncio, Arribas Alpuente (1); ML, Chust (1); A, Menendez (1); V, Crispin (1); JL, Guinot (1); JL, Mengual (1); PP, Escolar (1) (1) Instituto Valenciano de Oncología - Radiation Oncology Valencia, Spain
Vestibular schwannomas (VS): intracanalicular extension and associated hearing loss. Volumetric analyses P1-65 Ouzi, Nissim (1); Nicolas, Massager (2); Carine, Delbrouck (3); Philippe, David (4); Daniel, Devriendt (5); Françoise, Desmedt (1); Jacques, Brotchi (2); Marc, Levivier (1) (1) Hôpital Erasme - Centre Gamme Knife; (2) Hôpital Erasme - Neurochirurgie; (3) Hôpital Erasme - Centre Gamme Knife; (4) Hôpital Erasme - Neuroradiologie; (5) Institut J. Bordet - Radiothérapie Brussels, Belgium 39 Scientific Program
Radiosurgery of cerebellopontine angle tumors. Optimization of treatment and outcomes evaluation P1-66 Yaroslav, Parpaley (1); Miron, Sramka (1); Augustin, Durkovsky (2) (1) St. Elisabeth Cancer Institute - Department of Radiosurgery; (2) St. Elisabeth Cancer Institute - Department of Radiology Bratislava, Slovakia Monday 12/09/05 Gamma knife radiosurgery for vestibular schwannomas P1-67 Selcuk, Peker (1); Turker, Kilic (1); Meric, Sengoz (2); Necmettin, Pamir (1) (1) Marmara University School of Medicine - Department of Neurosurgery; (2) Marmara University - Radiation Oncology Istanbul, Turkey
Limitation of size for the radiosurgical treatment of vestibular schwannomas. Comparison between 2D and 3D informations P1-68 Pierre-Hugues, Roche (1); Jean, Regis (2) (1) CHU La Timone - neurochirurgie; (2) CHU La Timone - Service de Neurochirurgie Marseille, France
Linac radiosurgery for acoustic neuromas: experience at the CHU of Liège P1-69 Isabelle, Rutten (1); Bruno, Kaschten (2); Snezana, Kotolenko (3); Achille, Stevenaert (2); Jean-Marie, Deneufbourg (1) (1) CHU Liège - Radiothérapie; (2) CHU Liège - Neurochirurgie; (3) C.H. de Luxembourg - Radiotherapy Liège, Belgium
Early detection of tiny vestibular schwannoma by FIESTA MR Images and treated with gamma knife radiosurgery P1-70 Chain-Fa, Su (1); Tzu-Wen, Loh (1); Chou Chin, Lee (2); Wen-Lin, Hsu (3); Shinn-Zong, Lin (1) (1) Buddhist Tzu-Chi Medical Center, Tzu-Chi University - Department of Neurosurgery; (2) Buddhist Tzu-Chi Medical Center, Tzu-Chi University - Department of Radiology; (3) Buddhist Tzu-Chi Medical Center, Tzu-Chi University - Department of Radiation Oncology Hualien, Taiwan
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ORAL SESSIONS 11h30 - 12h30 12/09/05 Monday LARGE ARTERIOVENOUS MALFORMATIONS OS1 Chairmen: Andras, Kemeny; Jason, Sheehan Room Nation
Staged gamma knife radiosurgery, with neither surgery OS1-1 nor embolization, for relatively large AVMs Masaaki, Yamamoto (1); Bierta E., Barfod (1); Yoichi, Urakawa (1) (1) Katsuta Hospital - Mita Gamma House Hitaxhi-Naka, Japan
Validation of a radiosurgery-based grading system OS1-2 for arteriovenous malformations Michael, Girvigian (1); John, Lee (1); Michael, Miller (1); Javad, Rahimian (1); Joseph, Chen (1); Hugh, Greathouse (1); Michael, Tome (1) (1) Kaiser Permanente Medical Center - Department of Radiation Oncology Los Angeles, USA
Radiosurgery of large cerebral arteriovenous malformations OS1-3 Dong Gyu, Kim (1); Seung-Yeob, Yang (1); Sun Ha, Paek (1); Hyun-Tai, Chung (1); Chul-Kee, Park (1); Dae Hee, Han (2) (1) Seoul National University Hospital - Department of Neurosurgery; (2) Seoul National University Hospital - Department of Neurosurgery Seoul, Republic of Korea
Staged volume radiosurgery for large arteriovenous OS1-4 malformations: indications and outcomes Douglas, Kondziolka (1); Sait, Sirin (1); John C, Flickinger (1); Niranjan, Ajay (1) (1) University of Pittsburgh Medical Center - Department of Neurological Surgery Pittsburgh, USA
RADIOBIOLOGY OS2 Chairmen: John, Flickinger; Ronald, Mc Garry Room Permeke & Rembrandt
Stereotactic pulmonary hilar radiation: an animal model OS2-1 of radiotoxicity Brent, Tinnel (1); Marc, Mendonca (2); Ronald, McGarry (3); Oscar, Cummings (4); Robert, Timmerman (5) (1) Indiana University Medical Center - Department of Radiation Oncology; (2) Indiana University Medical Center - Radiation and Cancer Biology; (3) Indiana University Medical Center - Department of Radiation Oncology; (4) Indiana University School of Medicine - Department of Pathology; (5) University of Texas Southwestern - Department of Radiation Oncology Indianapolis, USA 41 Scientific Program
Histopathologic changes in metastatic brain tumors OS2-2 seen after gamma knife radiosurgery: the Pittsburgh experience Dave, Atteberry (1); Gyorgy, Szeifert (2); Marta, Couce (3); Douglas, Kondziolka (1); L. Dade, Lunsford (1) (1) University of Pittsburgh Medical Center - Department of Neurological Surgery; (2) National Institute of Neurosurgery - Department of Neurosurgery; (3) University of Pittsburgh Medical Center - Pathology Pittsburgh, USA Monday 12/09/05
Early and late adverse effects of low-dose radiosurgery OS2-3 in MR area Hiroshi K., Inoue (1) (1) Institute of Neural Organization - Restorative Neurosurgery Fujioka, Japan
Alpha/beta ratios for radiosurgical target tissues OS2-4 Frederik, Vernimmen (1); Jacobus, Slabbert (2) (1) Stellenbosch University - Radiation Oncology; (2) iThemba LABS - Radiation Biophysics Tygerberg, South Africa
GLIOMAS OS3 Chairmen: Minesh, Mehta; Nicolas, Massager Room Willumsen
PET-related metabolic response of glial tumors OS3-1 after GK radiosurgery Nicolas, Massager (1); Bich-Ngoc-Thanh, Tang (2); Daniel, Devriendt (3); Ouzi, Nissim (4); David, Wikler (2); Françoise, Desmedt (4); Jacques, Brotchi (1); Serge, Goldman (2); Marc, Levivier (4) (1) Hôpital Erasme - Neurochirurgie; (2) Hôpital Erasme - PET Scan; (3) Institut J. Bordet - Radiothérapie; (4) Hôpital Erasme - Centre Gamme Knife Brussels, Belgium
Rationale for, and results of a 6-year experience of leading OS3-2 edge gamma knife Radiosurgery for Glioblastoma Multiforme: A Trend Toward Improved Outcome Christopher M., Duma (1); W. Michael, Shea (2); Jay, Tassin (2); Peter, Chen (2); Ralph, Mackintosh (2); Marianne, Plunkett (2) (1) Hoag Memorial Hospital - Department of Neurosurgery; (2) Hoag Memorial Hospital - Radiation Oncology Newport Beach, USA
Quantification of surrogate tracers for glioma radiosensitization OS3-3 Peter, Haar (1); William, Broaddus (1); Zhijian, Chen (1); Panos, Fatouros (2) (1) Medical College of Virginia - Division of Neurosurgery; (2) Medical College of Virginia - Radiation Physics and Biology Richmond , USA 42 Scientific Program
Role of gamma knife radiosurgery in malignant OS3-4 12/09/05
glioma treatment Monday Masaaki, Yamamoto (1); Bierta E. Barfod (1); Yoichi, Urakawa (1) (1) Katsuta Hospital - Mita Gamma House Hitaxhi-Naka, Japan
SPONSORED SEMINAR 13h00 - 13h45
NOVALIS FOR FUNCTIONAL NEUROSURGERY Room Nation Seminar and lunch sponsored by BrainLAB Chairman: Antonio AF De Salles Antonio AF De Salles, MD, PhD; Alessandra Gorgulho, MD; Paul Medin, PhD; Nzhyde Agazarian, PhD; Timothy Solberg, Ph.D.; Michael Selch, MD UCLA - Departments of Neurosurgery and Radiation Oncology, Los Angeles, USA
ORAL SESSIONS 14h00 - 15h00
VESTIBULAR SCHWANNOMAS 1 OS4 Chairmen: L. Dade, Lunsford; Roberto, Spiegelmann Room Nation
Estimating tumor definition variability in acoustic OS4-1 schwannoma radiosurgery, and how it affects dosimetry John, Flickinger (1); Ajay, Niranjan (2); Kaan, Oysul (1); Juan, Martin (3); Sait, Sirin (4); Ann H., Maitz (5); Douglas, Kondziolka (5); L. Dade, Lunsford (5) (1) University of Pittsburgh Medical Center - Department of Radiation Oncology; (2) University of Pittsburgh Medical Center - Neurological Surgery; (3) Department of Neurological Surgery - University of Pittsburgh; (4) University of Pittsburgh Medical Center - Department of Neurological Surgery; (5) University of Pittsburgh Medical Center - Image Guided Neurosurgery Pittsburgh, USA
Hearing preservation in vestibular schwannoma after gamma OS4-2 knife radiosurgery Dong Gyu, Kim (1); Seung-Yeob, Yang (1); Sun Ha, Paek (1); Hyun-Tai, Chung (1); Chul-Kee, Park (1); Hee-Won, Jung (1) (1) Seoul National University Hospital - Department of Neurosurgery Seoul, Republic of Korea
Hearing preservation after GK radiosurgery for vestibular OS4-3 schwannoma: Influence of intracanalicular dosimetric parameters Nicolas, Massager (1); Ouzi, Nissim (2); Carine, Delbrouck (3); Daniel, Devriendt (4); Philippe, David (5); Françoise, Desmedt (2); David, Wikler (6); Jacques, Brotchi (1); Sergio, Hassid (7); Marc, Levivier (2) (1) Hôpital Erasme - Neurochirurgie; (2) Hôpital Erasme - Centre Gamme Knife; (3) Hôpital Erasme - Centre Gamme Knife; (4) Institut J. Bordet - Radiothérapie; (5) Hôpital Erasme - Neuroradiologie; (6) Hôpital Erasme - PET Scan; (7) Hôpital Erasme - ENT Dept. Brussels , Belgium 43 Scientific Program
A prospective series of 1000 vestibular schwannomas treated OS4-4 by “low dose” radiosurgery: long term results Jean, Regis (1); Pierre-Hugues, Roche (2); Christine, Delsanti (3); William, Pellet (1) (1) CHU La Timone - Service de Neurochirurgie; (2) CHU La Timone - neurochirurgie; (3) CHU La Timone - Gamma Unit Marseille, France Monday 12/09/05
LUNG TUMORS 1 OS5 Chairmen: Ingmar, Lax; Paul, VanHoutte Room Permeke&Rembrandt
A prospective trial on stereotactic radiotherapy of limited OS5-1 stage non-small cell lung cancer Morten, Hoyer (1); Henrik, Roed (2); Anders, Traberg Hansen (1); Lars Peter, Ohlhues (2); Jorgen, Petersen (1); Hanne, Nellemann (3); Anne Kiil, Berthelsen (2); Cai, Grau (1); Sv. Aage, Engelholm (2); Hans, von der Maase (1) (1) Aarhus University Hospital - Department of Oncology; (2) Copenhagen University Hospital - Department of Oncology; (3) Aarhus University Hospital - Department of Diagnostic Radiology Aarhus C, Denmark
CT appearance of radiation injury of the lung and clinical OS5-2 symptoms after stereotactic radiation therapy (SRT) for lung cancers Tomoki, Kimura (1); Yuji, Murakami (2); Kanji, Matsuura (3); Yasutoshi, Hashimoto (4); Masahiro, Kenjo (5); Yuko, Kaneyasu (6); Koichi, Wadasaki (7); Yutaka, Hirokawa (8); Motoomi, Ohkawa (9); Katsuhide, Ito (10) (1) Kagawa University - Radiology; (2) Hiroshima University School of Medicine - Radiology; (3) Hiroshima University School of Medicine - Radiology; (4) Hiroshima University School of Medicine - Radiology; (5) Hiroshima University School of Medicine - Radiology; (6) Hiroshima University School of Medicine - Radiology; (7) Hiroshima University School of Medicine - Radiology; (8) Juntendo University - Radiology; (9) Kagawa University - Radiology; (10) Hiroshima University School of Medicine - Radiology Kagawa Prefecture, Japan
CT-guided stereotactic radiotherapy for stage I non-small OS5-3 cell lung cancers: 10-year experiences with the fusion of CT and Linac (FOCAL) unit Minoru, Uematsu (1); Akira, Shioda (2) (1) Keio University - Department of Radiology; (2) National Defense Medical College - Radiation Oncology Tokyo , Japan
Dose-response relationship in fractionated stereotactic OS5-4 radiotherapy (FSRT) for non small cell lung cancer (NSCLC) Hilde, Van Parijs (1); Jan, Van de Steene (1); Vincent, Vinh-Hung (1); Dirk, Verellen (2); Guy, Storme (1) (1) AZ VUB - Radiothérapie; (2) AZ VUB - Physique Brussels , Belgium 44 Scientific Program
ORAL SESSIONS 15h00 - 16h00 12/09/05 Monday VESTIBULAR SCHWANNOMAS 2 OS6 Chairmen: L. Dade, Lunsford; Roberto, Spiegelmann Room Nation
Radiosurgery of facial neurinoma - Long-term results OS6-1 and functional outcome Yoshihisa, Kida (1) (1) Komaki City Hospital - Department of Neurosurgery Komaki Aichi, Japan
Risk of malignancy in the radiosurgical management OS6-2 of Type 2 Neurofibromatosis (NF2) Jeremy, Rowe (1); Alison, Grainger (1); Lee, Walton (2); Aurelia, Kollova (1); Matthias Walter Richard, Radatz (3); Andras A, Kemeny (1) (1) Royal Hallamshire Hospital - National Centre For Stereotactic Radiosurgery; (2) University of Sheffield - Department of Medical Physics and Clinical Engineering; (3) Royal Hallamshire Hospital - Department of Neurosurgery Sheffield, United Kingdom
Histopathological observations on vestibular Schwannomas OS6-3 following gamma knife radiosurgery Gyorgy, Szeifert (1); Dominique, Figarella-Branger (2); Pierre-Hugues, Roche (3); Marc, Levivier (4); Jean, Regis (5) (1) National Institute of Neurosurgery of Budapest; (2) CHU La Timone - Department of Pathology and Neuropathology; (3) CHU La Timone - neurochirurgie; (4) Hôpital Erasme - Centre Gamme Knife; (5) CHU La Timone - Service de Neurochirurgie Marseille, France
Avoidance of facial nerve dysfunction after GK radiosurgery: OS6-4 modified dose planning technique Masaaki, Yamamoto (1); Bierta E. Barfod (1); Yoichi, Urakawa (1) (1) Katsuta Hospital - Mita Gamma House Hitaxhi-Naka, Japan
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LUNG TUMORS 2 OS7 Chairmen: Ingmar, Lax; Paul, VanHoutte Room Permeke & Rembrandt
Dosimetric validation of a breathing synchronized irradiation OS7-1
Monday technique for hypofractionated lung treatments 12/09/05 Dirk, Verellen (1); Koen, Tournel (2); Nadine, Linthout (3); Guy, Storme (4) (1) AZ VUB - Physique; (2) AZ-VUB - Radiotherapy; (3) AZ-VUB - Radiotherapy; (4) AZ-VUB - Radiotherapy Brussels, Belgium
Stereotactic body radiation therapy for lung metastases: OS7-2 Impact on overall survival Martin, Fuss (1); Charles R., Thomas Jr. (1); Bill J., Salter (2); Terence S., Herman (1) (1) UTHSC San Antonio - Radiation Oncology; (2) Cancer Therapy & Research Center - Medical Physics San Antonio , USA
Metabolic PET imaging for stereotactic body radiation OS7-3 therapy planning and therapy response assessment of pulmonary malignancies Martin, Fuss (1); Bill J., Salter (2); Terence S., Herman (1); Charles R., Thomas Jr. (1) (1) UTHSC San Antonio - Radiation Oncology; (2) Cancer Therapy & Research Center - Medical Physics San Antonio, USA
Computed tomographical analysis of radiation sequelae OS7-4 due to experimental stereotactic irradiation to normal rabbit lung Takatsugu, Kawase (1); Etsuo, Kunieda (2); M Deloar, Hossain (2); Satoshi, Seki (2); Akitomo, Sugawara (2); Tatsuya, Fujisaki (3); Akitoshi, Ishizaka (4); Atsushi, Kubo (2) ( 1 ) Keio University - Department of Radiation Oncology ,( 2 ) Keio University - Department of Radiology, (3) Ibaraki Prefectural University of Health Sciences - Department of Radiological Sciences , ( 4 ) Keio University - Department of Medicine
ORAL SESSIONS 17h00 - 18h00
VESTIBULAR SCHWANNOMAS 3 OS8 Chairmen: L. Dade, Lunsford; Jean, D’Haens Room Nation
Five session gamma knife treatment of acoustic neuromas OS8-1 Steven, Cobery (1); Melissa, Remis (2); Carla, Bradford (2); Georg, Noren (2) (1) Brown University - Department of Neurosurgery; (2) Rhode Island Hospital, Brown University - New England Gamma Knife Center Providence, USA
46 Scientific Program
Evaluation of ophthalmological consequences of gamma OS8-2 12/09/05
knife radiosurgery in vestibular Schwannomas Monday Manabu, Tamura (1); Noriko, Murata (2); Motohiro, Hayashi (3); Jean, Regis (4) (1) Timone University Hospital - Stereotactic and Fonctional Neurosurgery; (2) Timone University Hospital - Stereotactic and Fonctional Neurosurgery; (3) Tokyo Women's Medical Univeristy - Department of Neurosurgery; (4) CHU La Timone - Service de Neurochirurgie Marseille, France
Relative safety of gamma knife radiosurgey in CPA angle OS8-3 tumors with significant brainstem compression Mohammad Ali, Bitaraf (1); Mazdak, Alikhani (2); Mazyar, Azar (3); Frarid, Kazemi (4) (1) Tehran university of medical sciences - Neurosurgery; (2) Tehran university of medical sciences - Neurosurgery; (3) Iran university of medical sciences - neurosurgery; (4) Iran university of medical sciences - Neurosurgery Tehran, Iran
Hypofractionated stereotactic radiotherapy as primary OS8-4 treatment of acoustic neuroma: Interim results of the Johns Hopkins experience Ori, Shokek (1); Stephanie, Terezakis (1); Michael, Hughes (1); Lawrence, Kleinberg (1); Moody, Wharam (1); Daniele, Rigamonti (2) (1) The Johns Hopkins University School of Medicine - Department of Radiation Oncology and Molecular Radiation Sciences; (2) Johns Hopkins University School of Medicine - Department of Neurosurgery Baltimore, USA
OTHER TUMORS OS9 Chairman: Ingmar, Lax; Rita, Engenhart-Cabillic Room Permeke & Rembrandt
Epidermoid cyst treated with gamma knife radiosurgery OS9-1 Jeremy, Ganz (1); Ayman, Hafez (1); W A., Reda (1) (1) Cairo Nasser Institute - Gamma Knife Center Cairo, Egypt
Stereotactic radiation for cystic craniopharyngiomas OS9-2 Alessandra, Gorgulho (1); Carlos, Mattozo (1); Murisiku, Raifu (1); Katayoun, Tajik (1); Michael, Selch (2); Nzhde, Agazaryan (5); Timothy, Solberg (5); Daniel, Kelly (1); Antonio, De Salles (1) (1) UCLA Medical Center - Department of Neurosurgery; (2) UCLA Medical Center - Department of Radiation Oncology Los Angeles, USA
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Radiosurgery of epidermoid tumor - OS9-3 Trial for radiosurgical nerve decompression Yoshihisa, Kida (1) (1) Komaki City Hospital - Department of Neurosurgery Komaki Aichi, Japan
Fulminate peritumoral brain edema following radiosurgery OS9-4 for meningiomas: Report of two cases and review of the literature Guus, Koerts (1); Dirk, Van Den Berge (2); Christian, Raftopoulos (3); Jean, D'Haens (4) (1) Cliniques Universitaires Saint-Luc - Neurosurgery; (2) AZ VUB - Radiothérapie; (3) Cliniques Universitaires Saint-Luc - Neurochirurgie; (4) AZ VUB - Neurochirurgie Brussels, Belgium
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Tuesday 13/09/05
Breakfast seminars 7h30 - 8h30
WHAT RISK OF CANCEROGENESIS IN RADIOTHERAPY BS4 AND RADIOSURGERY? Room Rembrandt 13/09/05 Risks and relative risks of malignancy after cranial irradiation BS4-1 T Jeremy, Rowe uesday
A review of the literature on cancerogenesis after radiosurgery BS4-2 Jeremy, Ganz
Relative risk of cancerogenesis after fractionated BS4-3 and single-dose stereotactic irradiation John, Flickinger
RADIOSURGERY FOR ARTERIOVENOUS MALFORMATIONS BS5 Room Permeke
Challenges in AVM radiosurgery BS5-1 Douglas, Kondziolka
What strategy in large AVM? BS5-2 Andras, Kemeny
Lessons from the past. Issues for the future BS5-3 Federico, Colombo
PHYSICS - NEW TECHNOLOGIES BS6 Room Willumsen
Today’s technology and application of a dedicated BS6-1 neuro-radiosurgery system Franz, Krispel
Final design, integration and testing of the dedicated proton BS6-2 SRS/SRT beamline at the NPTC Marc R., Bussière
One year of Cyberknife radiosurgery BS6-3 Michael, Schulder 49 Scientific Program
PLENARY SESSION 8h45 - 10h00
PS2 Room Nation
DATA BLITZ UPDATE 1 PS2-1 Extracranial Radiosurgery Ingmar, Lax
DATA BLITZ UPDATE 2 PS2-2 Vestibular Schwannomas L. Dade, Lunsford uesday T 13/09/05 BRAIN METASTASES Chairman: Ingmar, Lax; L. Dade, Lunsford
Radiosurgery for the treatment of 239 patients with brain PS2-3 metastases: estimation of patients eligibility using three stratification systems Daniel, Devriendt (1); José, Lorenzoni (2); Nicolas, Massager (3); Philippe, David (4); David, Wikler (5); Daniel Salvador, Ruiz Gonzalez (6); Bruno, Vanderlinden (7); Paul, Van Houtte (1); Jacques, Brotchi (3); Marc, Levivier (2) (1) Institut J. Bordet - Radiothérapie; (2) Hôpital Erasme - Centre Gamme Knife; (3) Hôpital Erasme - Neurochirurgie; (4) Hôpital Erasme - Neuroradiologie; (5) Hôpital Erasme - PET Scan; (6) Medica Sur SA de CV MSU 820125 T58 - Unidad Gamma Knife; (7) Institut J. Bordet - Physique Brussels, Belgium
Long-term Survivors after gamma knife Radiosurgery PS2-4 for Brain Metastases Douglas, Kondziolka (1); Juan, Martin (2); John C, Flickinger (1); L. Dade, Lunsford (1) (1) University of Pittsburgh Medical Center - Department of Neurological Surgery; (2) Department of Neurological Surgery - University of Pittsburgh Pittsburgh, USA
A randomized trial of surgery and radiotherapy versus PS2-5 radiosurgery alone in the treatment of single metastasis to the brain Alexander, Muacevic (1); Berndt, Wowra (1); Joerg, Tonn (2); Hans-Jakob, Steiger (3); Friedrich, Kreth (1) (1) European Cyberknife Center Munich - Cyberknife Center; (2) Ludwig-Maximilians-University, Klinikum Großhadern - Department of Neurosurgery; (3) University Duesseldorf - Department of Neurosurgery Munich, Germany
50 Scientific Program
ORAL SESSIONS 10h30 - 11h30
BRAIN METASTASES 1 OS10 Chairmen: Masaaki, Yamamoto; Minesh, Mehta Room Nation
Recursive partitioning analysis of prognostic factors for OS10-1 patients treated with four or more intracranial metastases treated with radiosurgery 13/09/05
Ajay, Bhatnagar (1); Douglas, Kondziolka (2); L. Dade, Lunsford (2); John C, Flickinger (2) T (1) University of Pittsburgh Cancer Institute - Radiation Oncology; (2) University of Pittsburgh Medical Center uesday - Department of Neurological Surgery Pittsburgh, USA
Extracranial tumoractivity determines survival after OS10-2 gamma knife radiosurgery for brain metastases Patrick, Hanssens (1); Guus, Beute (2); Theo, Veninga (3); Suente, Lie (2); Koo, van Overbeeke (2); Danielle, Eekers (1) (1) Gamma Knife Center Tilburg - Radiation Oncology; (2) Gamma Knife Center Tilburg - Neurosurgery; (3) Gamma Knife Center Tilburg - Radiation Oncology Tilburg, The Netherlands
Diffusion magnetic resonance imaging as an early OS10-3 evaluation of the response of brain metastases treated by stereotactic radiosurgery Chuan-Fu, Huang (1) (1) Chung Shan Medical University Hospital - GammaKnife Center Taichung, Taiwan
Gamma knife radiosurgery alone as an alternative treatment OS10-4 for melanoma brain metastasis Xavier, Muracciole (1); Jean, Regis (2) (1) CHU La Timone - Service de Radiothérapie; (2) CHU La Timone - Service de Neurochirurgie Marseille, France
MENINGIOMAS 1 OS11 Chairmen: Hidefumi, Jokura; Robert, Smee Room Permeke & Rembrandt
Hypofractionated stereotactic radiotherapy for benign OS11-1 Michael, Dally (1); Louise, Gorman (1); Jeremy, Reuben (1); Robert, Myers (1) (1) The Alfred Hospital - Radiation Oncology Department Melbourne, Australia
51 Scientific Program
Stereotactic Radiosurgery and Fractionated Stereotactic OS11-2 Radiotherapy for Meningiomas Related to the Optic Apparatus Leonardo, Frighetto (1); Carlos, Mattozo (2); Alessandra, Gorgulho (3); Michael, Selch (4); Cynthia, Cabatan- Awang (3); Timothy, Solberg (4); Antonio, DeSalles (5) (1) University of California Los Angeles - Neurosurgery; (2) UCLA Medical Center - Neurosurgery; (3) UCLA Medical Center - Department of Neurosurgery; (4) UCLA - Radiation Oncology; (5) UCLA Medical Center - Neurosurgery Los Angeles, United States
Improvement in vision and other cranial neuropathies OS11-3 after stereotactic radiotherapy for the treatment of skull base meningiomas Tracy, McElveen (1); Kathleen, Settle (1); Beverly, Downes (2); Maria, Werner-Wasik (1); Wally, Curran (1); uesday
T David, Andrews (3) 13/09/05 (1) Thomas Jefferson University - Radiation Oncology/Neurosurgery; (2) Jefferson Hospital for Neuroscience - Department of Neurosurgery Philadelphia, USA
Optic nerve sheath meningiomas. OS11-4 The role for stereotactic radiotherapy Robert Ian, Smee (1); Margaret, Schneider (1); Janet, Williams (1) (1) University of New South Wales - Prince of Wales Hospital - Department of Radiation Oncology Randwick, Australia
PHYSICS – GENERAL OS12 Chairmen: Frank, Bova; Stephan G., Scheib Room Willumsen
Stereotactic IMRS for intracranial tumours OS12-1 Robert Ian, Smee (1); Margaret, Schneider (1) (1) University of New South Wales - Prince of Wales Hospital - Department of Radiation Oncology Randwick, Australia
Monte Carlo simulation for gamma knife radiosurgery OS12-2 using the Grid Vasu, Ganesan (1); Rami, Mehrem (2); John, Fenner (2); Lee, Walton (1) (1) University of Sheffield - Department of Medical Physics and Clinical Engineering; (2) Royal Hallamshire Hospital - National Centre For Stereotactic Radiosurgery Sheffield, United Kingdom
Artificial Droplets improves radiation dosimetry of IMRT OS12-3 Kevin, Khadivi (1); Robert, Comiskey (2); Timothy, Klapproth (3); Craig, Hansen (3) (1) Mercy Medical Center - Radiation Oncology; (2) Radionics, a division of Tyco HealthCar - Engineering; (3) Mercy Medical Center - Radiation Oncology Springfield, USA 52 Scientific Program
Standardization for CyberKnife Beam Dosimetry OS12-4 Hidetoshi, Saitoh (1); Toru, Kawachi (2); Mitsuhiro, Inoue (3); Atsushi, Myojyoyama (4); Tatsuya, Fujisaki (5); Shinji, Abe (5); Kimiaki, Saito (6) (1) Tokyo Metropolitan University of Health Sciences - Graduate School of Health Sciences; (2) Tokyo Metropolitan University - Graduate School of Health Sciences; (3) Midori Kai Neurosurgery Hospital - Yokohama CyberKnife Center; (4) Tokyo Metropolitan University - Graduate School of Health Sciences; (5) Ibaraki Prefectural University of Health Sciences - Department of Radiological Sciences; (6) Japan Atomic Energy Research Institute - Health Physics Tokyo, Japan 13/09/05 T ORAL SESSIONS 11h30 - 12h30 uesday
BRAIN METASTASES 2 OS13 Chairmen: Masaaki, Yamamoto; Minesh, Mehta Room Nation
Hypofractionated stereotactic radiotherapy for brain OS13-1 metastases not amenable to radiosurgery Antje, Ernst-Stecken (1); Ulrike, Lambrecht (1); Oliver, Ganslandt (1); Rudolf, Fahlbusch (1); Rolf, Sauer (1); Gerhard, Grabenbauer (1) (1) Novalis Shaped Beam Surgery Center, University Hospital of Erlangen, Germany - Radiation Oncology
Response rate and biologically effective dose correlation OS13-2 in stereotactic irradiation of adenocarcinoma brain metastasis Filippo, Grillo-Ruggieri (1); Paolo, Cavazzani (2); Massimo, Cardinali (3); Giovanna, Mantello (4); Stefania, Maggi (5) (1) Ospedali Galliera - Radioterapia; (2) Ospedali Galliera, Genova, Italy - Neurochirurgia; (3) Ospedali Riuniti, Ancona, Italy - Radioterapia; (4) Ospedali Riuniti, Ancona, Italy - Radioterapia; (5) Ospedali Riuniti, Ancona, Italy - Fisica Sanitaria Genova, Italy
Gamma knife surgery for large metastatic brain tumors OS13-3 to avoid developing severe peritumoral edema Motohiro, Hayashi (1); Taku, Ochiai (1); Masahiro, Izawa (1); Mikhail, Chernov (1); Koutaro, Nakaya (1); Tomokatsu, Hori (1) (1) Tokyo Women's Medical University - Department of Neurosurgery Tokyo, Japan
53 Scientific Program
Gamma knife surgery for metastatic brain tumors OS13-4 from lung cancer Toru, Serizawa (1); Yoshinori, Higuchi (2); Shinji, Matsuda (3); Junichi, Ono (4); Makoto, Sato (5); Toshihiko, Iuchi (6); Osamu, Nagano (7); Naokatsu, Saeki (8) (1) Chiba Cardiovascular Center - Department of Neurosurgery; (2) Chiba Cardiovascular Center - Department of Neurosurgery; (3) Chiba Cardiovascular Center - Department of Neurology; (4) Chiba Cardiovascular Center - Department of Neurosurgery; (5) Chiba Cardiovasucular Center - Department of Radiology; (6) Chiba Cancer Center - Division of Neurological Surgery; (7) Graduate School of Medicine, Chiba University - Department of Neurological Surgery; (8) Graduate School of Medicine, Chiba University - Department of Neurological Surgery Chiba, Japan
MENINGIOMAS 2 OS14 uesday Chairmen: Hidefumi, Jokura; Robert, Smee Room T 13/09/05 Permeke & Rembrandt
The Role of Radiosurgery in the Management OS14-1 of Petroclival Meningiomas Dong Gyu, Kim (1); Chul-Kee, Park (1); Hyun-Tai, Chung (1); Sun Ha, Paek (1); Hee-Won, Jung (1) (1) Seoul National University Hospital - Department of Neurosurgery Seoul, Republic of Korea
Gamma knife radiosurgery for cavernous sinus meningiomas - OS14-2 ten year follow-up period Martina, Stippler (1); John, Lee (2); John C, Flickinger (3); Douglas, Kondziolka (3); L. Dade, Lunsford (4) (1) University of Pittsburgh Medical Center - Neurological Surgery; (2) Hospital of the University of Pennsylvania - Neurosurgery; (3) University of Pittsburgh Medical Center - Department of Neurological Surgery; (4) University of Pittsburgh Medical Center - Image Guided Neurosurgery Pittsburgh, USA
Gamma knife radiosurgery of skull base meningiomas OS14-3 Roman, Liscak (1); Aurelia, Kollova (2); Vilibald, Vladyka (3); Gabriela, Simonova (1); Josef, Novotny Jr. (4) (1) Hospital Na Homolce - Stereotactic Neurosurgery Department; (2) Royal Hallamshire Hospital - National Centre For Stereotactic Radiosurgery; (3) Na Homolce Hospital - Stereotactic and Radiation Neurosurgery; (4) Hospital Na Homolce - Medical Physics Department Prague, Czech Republic
Linac Radiosurgery for the management of cavernous OS14-4 sinus meningiomas Salvador, Somaza (1) (1) La Floresta Medical Institute - Stereotactic Radiosurgery Unit Miami, USA
54 Scientific Program
PHYSICS – LEAKAGE OS15 Chairmen: Stephan G, Scheib; Stéphane, Simon Room Willumsen
Measurement of the exit dose to the neck from intracranial OS15-1 stereotactic radiotherapy, using the M3 mini MLC Dror, Alezra (1); Janna, Menhel (1); Rafael, Pfeffer (1); Roberto, Spiegelmann (2) (1) Sheba Medical Center - Department of Oncology; (2) Sheba Medical Center - Department of Neurosurgery Ramat Gan, Israel 13/09/05 T
Dosimetry of thyroid, parotid and ovarian glands in patients OS15-2 uesday undergoing gamma knife radiosurgery Mahmoud, Allahverdi (1); Aliakbar, Sharafi (2); Alireza, Nikoofar (3); Hadi, Hassanzadeh (4) (1) Tehran university of medical sciences - Cancer institute,radiotherapy physics; (2) Iran Medical Science Of University, Ali Asghar Hospital - Iran Gamma Knife Center; (3) Iran university of medical sciences - Medical Physics; (4) Iran university of medical sciences - Medical Physics Tehran, Iran
In vivo estimation of extracranial doses in stereotactic OS15-3 radiosurgery with the gamma knife and Novalis systems Thierry, Gevaert (1); Dirk, Verellen (2); Stéphane, Simon (3); Françoise, Desmedt (1); Bob, Schaeken (4) (1) Hôpital Erasme - Centre Gamme Knife; (2) AZ VUB - Physique; (3) Institut J. Bordet - Physique; (4) AZ Middelheim - Physique Brussels, Belgium
55 Scientific Program uesday T 13/09/05
56 Scientific Program
Wednesday 14/09/05
BREAKFAST SEMINARS 7h30 - 8h30
EPILEPSY BS7 Room Rembrandt
The Ruber Hospital experience in MLTE radiosurgery BS7-1 Roberto, Martinez
Radiosurgery for epilepsy: Preliminary experience BS7-2 of U.S. multi-centric trial David, Larson
Long-term clinical results and their teachings BS7-3 W 14/09/05
Jean, Regis ednesday
BRAIN METASTASES BS8 Room Permeke
Evidence supporting the use of radiosurgery in brain BS8-1 metastases Minesh, Mehta
Radiosurgery for multiple brain metastases BS8-2 Masaaki, Yamamoto
Role of hypofractionated stereotactic radiotherapy BS8-3 in brain metastases Stecken, Ernst
PHYSICS - QUALITY ASSURANCE BS9 Room Willumsen
Analyzing 3T MR-scanners for implementation BS9-1 in radiosurgery Andreas, Mack
New challenges for QA in radiosurgery BS9-2 Lee, Walton
QA in the use of non stereotactic images (PET, …) BS9-3 in radiosurgery Josef Novotny Jr. 57 Scientific Program
PLENARY SESSION 8h45 - 10h00
PS3 Room Nation
DATA BLITZ UPDATE 3 PS3-1 Brain Metastases Minesh, Mehta
DATA BLITZ UPDATE 4 PS3-2 Physics Frank, Bova
COMPARATIVE TECHNOLOGIES Chairmen: Minesh, Mehta; Frank, Bova
Patterns of practice in a radiosurgery center equipped PS3-3 with both gamma knife and Linear Accelerator Robin, Stern (1); Julian, Perks (1); Allan, Chen (1)
ednesday (1) U.C. Davis Cancer Center - Radiation Oncology 14/09/05 Sacramento, USA W
The Rotating Gamma System GammaART-6000: PS3-4 A review of the first 100 patient treatments Helenowski Tomasz K. Stereotactic Radiosurgery Institute - Neurosurgery Gurnee, USA
Interstitial stereotactic radiosurgery PS3-5 Christopher, Ostertag Freiburg, Germany
58 Scientific Program
POSTER SESSION 10h30 - 11h30
PHYSICS, MOLECULAR IMAGING, MENINGIOMAS, P2 FUNCTIONAL RADIOSURGERY, SPINAL RADIOSURGERY, Room Holbein, PITUITARY TUMORS Turner & Foyer
Stereotactic neurosurgery for central pain P2-1 Yong-sheng, Hu (1); Yong-Jie, Li (2) (1) Beijing Xuanwu Hospital - Department of Functional Neurosurgery, Xuan Wu Hospital, Capital University of Medical Sciences; (2) Beijing Xuanwu Hospital - Department of Functional Neurosurgery, Xuan Wu Hospital, Capital University of Medical Sciences Beijing, China
Cyberknife radiosurgery for hypothalamic harmatoma in patient with medically intractable epilepsy and precocious puberty P2-2 Kyung Jin, Lee (1); Kyung-Sool, Jang (2) (1) St Mary's Hospital - Department of Neurosurgery; (2) St.Mary's hospital - Neurosurgery W 14/09/05 Seoul, Republic of Korea ednesday
LINAC radiosurgery for hypothalamic hamartoma epilepsy P2-3 Vladimir, Zaccariotti (1) (1) Association Against Cancer of Goias - Department of Neurosurgery Goias, Brazil
Gamma knife radiosurgery for intracranial meningiomas: Relationship between shrinkage and symptom relief P2-4 Jeremy, Ganz (1); Amr, El Shehaby (1); Hafez, Ayman (1) (1) Cairo Nasser Institute - Gamma Knife Center Cairo, Egypt
A prospective multicenter study about tumor volume reduction after stereotactic radiotherapy of skull base meningiomas P2-5 Martin, Henzel (1); Markus W, Gross (1); Klaus, Hamm (2); Gunnar, Surber (3); Gabriele, Kleinert (3); Gerd, Strassmann (1); Rita, Engenhart-Cabillic (3) (1) Philipps University Marburg, Germany - Dept. of Radiation Oncology; (2) Helios Klinikum Erfurt, Germany - Dept. for Stereotactic Neurosurgery and Radiosurgery; (3) Philipps University Marburg - Radiotherapy and Radiooncology Department Marburg, Germany
Fractionated stereotatic radiotherapy of base of skull meningiomas: a preliminary comparison in the delineation of the gross target volume between 4 medical specialities P2-6 Carine, Mitine (1); Laurent, Gilbeau (2); Frederic, Dessy (2); Christelle, Pirson (2); Jean-Francois, Rosier (2); Marie-Therese, Hoornaert (2); Ludovic, Harzee (2); Anne, Doneux (2) (1) Jolimont hospital - Radiotherapy; (2) Hôpital de Jolimont - Radiotherapie Haine St Paul, Belgium 59 Scientific Program
Stereotactic radiation therapy for optic meningioma; an experience of Ramathibodi Hospital P2-7 Chomporn, Sitathanee (1); Mantana, Dhanachai (1); Putipan, Puataweepong (1); Lojana, Tuntiyatorn (1); Anuchit, Poonyathalang (2); Veerasak, Theerapanchareon (3) (1) Ramathibodi Hospital Mahidol University - Department of Radiology; (2) Ramathibodi Hospital Mahidol University - Ophthalmology; (3) Ramathibodi Hospital Mahidol University - Neurosurgery Department Bangkok, Thailand
Long-term follow-up of sellar and para-sellar meningiomas treated with stereotactic radiosurgery and fractionated stereotactic radiotherapy using the UCLA grading system P2-8 Carlos, Mattozo (1); Leonardo, Frighetto (2); Alessandra, Gorgulho (3); Cynthia, Cabatan-Awang (3); Timothy D., Solberg (4); Michael, Selch (5); Antonio, DeSalles (6) (1) UCLA Medical Center - Neurosurgery; (2) University of California Los Angeles - Neurosurgery; (3) UCLA Medical Center - Department of Neurosurgery; (4) UCLA Medical Center - Department of Radiation Oncology; (5) UCLA - Radiation Oncology; (6) UCLA Medical Center - Neurosurgery Los Angeles, USA
Decision tree software: stereotactic radiation X conventional surgery P2-9 Alessandra, Gorgulho (1); Antonio, De Salles (1); Martin, Pellinat (2) (1) UCLA Medical Center - Department of Neurosurgery; (2) Idego Methodologies - VisionTree Healthcare ednesday 14/09/05 Los Angeles, USA W
Quality of life after interdisciplinary treatment of cavernous sinus meningiomas P2-10 Markus, Gross (1); Ahmed, Farhoud (2); Martin, Henzel (1); Stefan, Heinze (2); Ulrich, Sure (2); Helmut, Bertalanffy (2); Rita, Engenhart-Cabillic (3) (1) Philipps University Marburg - Department of Radiotherapy; (2) Philipps University Marburg - Department of Neurosurgery; (3) Philipps University Marburg - Radiotherapy and Radiooncology Department Marburg, Germany
Stereotactic radiosurgery for atypical and anaplastic meningiomas P2-11 Hideyuki, Kano (1); JUn, Takahashi (2); Norio, Araki (3); Masumi, Hiraoka (3); Naohiro, Horii (4); Kasumi, Araki (1); Tetsuya, Ueba (1); Kosuke, Yamashita (1); Nobuo, Hashimoto (2) (1) Kishiwada City Hospital - Neurosurgery; (2) Kyoto University Graduate School of Medicine - Neurosurgery; (3) Kyoto University Graduate School of Medicine - Radiation Oncology Department; (4) Kishiwada City Hospital - Radiation Oncology Kishiwada, Osaka
Long-term experience of gamma knife radiosurgery for benign skull base meningiomas P2-12 Wolfgang, Kreil (1); Verena, Weigl (1); Sandro, Eustacchio (1); Josef, Luggin (1); Georg, Papaefthymiou (1) (1) Medical University Graz - Dept. of Neurosurgery Graz, Austria 60 Scientific Program
Gamma knife radiosurgery for the treatment of skull base meningiomas P2-13 Selcuk, Peker (1); Turker, Kilic (1); Meric, Sengoz (2); Necmettin, Pamir (1) (1) Marmara University School of Medicine - Department of Neurosurgery; (2) Marmara University - Radiation Oncology Istanbul, Turkey
Stereotactic LINAC-radiosurgery for meningiomas P2-14 Salvador, Somaza (1) (1) La Floresta Medical Institute - Stereotactic Radiosurgery Unit Miami, USA
LINAC radiosurgery in the management of parasagittal meningiomas P2-15 Roberto, Spiegelmann (1); Jacob, Zauberman (2); Janna, Menhel (3); Rafael, Pfeffer (3); Dror, Alezra (3) (1) Sheba Medical Center - Department of Neurosurgery; (2) Sheba Medical Center - Neurosurgery; (3) Sheba
Medical Center - Department of Oncology W 14/09/05
Ramat Gan, Israel ednesday
Optic nerve sheath meningioma : Comparison of 3D-conformal radiotherapy (3D-CRT), stereotactic radiotherapy (SRT), and intensity modulated radiotherapy (IMRT) P2-16 Pornpan, Yongvithisatid (1); Porntip, Thamwinitchai (2); Paitoon, Tawsagul (1); Mantana, Dhanachai (1); Sawwanee, Asavaphatiboon (3); Chumpoj, Kakanaporn (2); Wichan, Prasertsilpakul (1); Chirapha, Tannanonta (1); Jiraporn, Laothamatas (1); Prasert, Assavaprathuangkul (1); Kanjana, Boonpitak (1) (1) Ramathibodi Hospital Mahidol University - Department of Radiology; (2) Siriraj Hospital - Radiology; (3) Ramathibodi Hospital Mahidol University - Radiology Bangkok, Thailand
Does diffuse white matter change often seen after WBRT also occur after GK for multiple brain METs? P2-18 Masaaki, Yamamoto (1) (1) Katsuta Hospital - Mita Gamma House Hitaxhi-Naka, Japan
Stereotactic irradiation for choroidal melanoma in the elderly P2-19 Stéphanie, Bolle (1); Isabelle, Rutten (1); Jean-Marie, Deneufbourg (1) (1) CHU Liège - Radiothérapie Liège, Belgium
Conformal stereotactic radiotherapy in the management of the orbital hemangioma P2-20 F, Mascarenhas (1); M, Santos (1); I, Monteiro Grillo (1); A, Almeida (2) (1) Hospital de Santa Maria- Lisboa-Portugal - Radiotherapy Dpt; (2) Hospital de Santa Maria- Lisboa-Portugal - Radiology Dpt Lisboa, Portugal 61 Scientific Program
Accuracy in ophthalmic radiosurgery - eye fixation, imaging, dosimetry P2-21 Josef, Novotny Jr. (1); Josef, Novotny (2); Roman, Liscak (3); Vaclav, Spevacek (4); Jan, Hrbacek (5); Pavel, Dvorak (6); Tomas, Cechak (7); Josef, Vymazal (8) (1) Na Homolce Hospital - Medical physics; (2) Na Homolce Hospital - Medical physics; (3) Na Homolce Hospital - Stereotactic and radiation neurosurgery; (4) CTU in Prague, Faculty of Nuclear Science and Physical Engineering - Dosimetry and application of ionizing radiation; (5) CTU in Prague, Faculty of Nuclear Science and Physical Engineering - Dosimetry and application of ionizing radiation; (6) CTU in Prague, Faculty of Nuclear Science and Physical Engineering - Dosimetry and application of ionizing radiation; (7) CTU in Prague, Faculty of Nuclear Science and Physical Engineering - Dosimetry and application of ionizing radiation; (8) Na Homolce Hospital - Stereotactic and radiation neurosurgery Prague, Czech Republic
Combined positron emission tomography and magnetic resonance imaging in the dosimetry planning of radiosurgery using Leksell gamma knife for intracranial tumors in children. Preliminary experience P2-23 Benoit, Pirotte (1); Serge, Goldman (2); Philippe, David (3); Daniel, Devriendt (4); Jacques, Brotchi (1); Patrick, Van Bogaert (5); Marc, Levivier (6) (1) Hôpital Erasme - Neurochirurgie; (2) Hôpital Erasme - PET Scan; (3) Hôpital Erasme - Neuroradiologie; (4) Institut J. Bordet - Radiothérapie; (5) Hôpital Erasme - Paediatric Neurology; (6) Hôpital Erasme - Centre Gamme Knife ednesday
14/09/05 Brussels, Belgium W Integration of CT-PET and MRI images in stereotactic procedures using hardware coregistration P2-24 Piero, Picozzi (1); Luca, Attuati (2); Alberto, Franzin (2); Lorenzo, Gioia (2); Claudio, Landoni (3); V.V, Dolenc (4) (1) Ospedale San Raffaele - Stereotactic Neurosurgery & Gamma Knife Department; (2) Ospedale San Raffaele - Neurosurgery Department; (3) Ospedale San Raffaele - Dept. of Nuclear Medicine; (4) University of Ljubljana, Clinical Center - Department of Neurosurgery Milano, Italy
Role of positron emission tomography in stereotactic radiosurgery with gamma knife P2-25 Yoshimasa, Mori (1); Tatsuya, Kobayashi (1); Naoki, Hayashi (1); Yuta, Shibamoto (2); Jun, Yoshida (3) (1) Nagoya Kyoritsu Hospital - Gamma Knife Center; (2) Nagoya City University - Department of Radiology and Radiation Oncology; (3) Nagoya University School of Medicine - Department of Neurosurgery Nagoya, Japan
Tomotherapeutic intensity-modulated radiosurgery (IMRS): improving dose gradients and maximum dose after inverse optimization using ActiveRx P2-26 Martin, Fuss (1); Bill J., Salter (2) (1) UTHSC San Antonio - Radiation Oncology; (2) Cancer Therapy & Research Center - Medical Physics San Antonio, USA 62 Scientific Program
Radiosurgery, staged radiosurgery and fractionated radiosurgery: experiences of gamma knife and CyberKnife P2-27 Hiroshi K., Inoue (1) (1) Institute of Neural Organization - Restorative Neurosurgery Fujioka, Japan
Today’s technology and application of a dedicated neuro-radiosurgery systems P2-28 Franz, Krispel (1) (1) American Radiosurgery, Inc. - Research and Development San Diego, USA
Dynamic patient positioning using Leksell gamma knife P2-29 Stefan G, Scheib (1); Stefano, Gianolini (2); Friederike, Reich (3) (1) Klinik im Park - Gamma Knife Center; (2) Klinik im Park - Department of Medical Radiation Physics; (3) Unitversity of Applied Science Remagen - Department of Medical Engineering and Sports-Medical
Engineering W 14/09/05
Zürich, Switzerland ednesday
Extracranial stereotactic IMRT - A study of set-up reproducibility P2-30 Meg, Schneider (1); Robert, Smee (1); Lyn, Emanuel (2); John, Way (3); Karl, Chan (4) (1) Prince of Wales Hospital - Department of Radiation Oncology; (2) University of New South Wales - Prince of Wales Hospital - Department of Radiation Oncology; (3) Prince of Wales Hospital - Physics Department of Radiation Oncology Randwick, Australia
Implementation of A 6D robotic couch-top for the automation of image-guided brain SRS and spinal SRT P2-31 Almon, Shiu (1); Eric, Chang (2); Conjung, Wang (1) (1) The University of Texas M.D. Anderson Cancer Center - Radiation Physics; (2) The University of Texas M.D. Anderson Cancer Center - Radiation Oncology Houston, USA
Targeting accuracy of a novel image guided gating system for stereotactic body radiotherapy P2-32 Stephen, Tenn (1); Paul, Medin (1); Timothy D., Solberg (1) (1) UCLA Medical Center - Department of Radiation Oncology Los Angeles, USA
Comparison of five radiosurgery treatment planning techniques: Is it a case of "six of the one, half a dozen of the other?" P2-33 Hester, Burger (1); Audrey, Pentz (1) (1) Netcare Group of Hospitals - Medical Physics Division Johannesburg, South Africa 63 Scientific Program
Feasibility of implanted fiducial markers for patient positioning for cranial radiotherapy P2-34 Rosa, Cañon (1); Ignacio, Azinovic (2); Mario, Lobato (2); Francisco, Garcia-Cases (2); Maricarmen, Heredia (2); Jose, Navarro (3); Jose, Martinez (2) (1) Hospital San Jaime - Oncology Platform, Radiation Oncology; (2) Hospital San Jaime - Oncology Platform, Radiation Oncology; (3) Hospital San Jaime - Neurosurgery Torrevieja, Spain
Dynamic extracranial robotic radiosurgery by means of a real-time motion correction system: analysis of the reduction of the planning target volume compared to the static technique P2-35 Franco, Casamassima (1); Giovanni, Ambrosino (2); Paolo, Francescon (3); Carlo, Cavedon (3); Joseph, Stancanello (3); Stefania, Cora (3); Michele, Avanzo (3); Paolo, Scalchi (3) (1) University of Firenze - Department of Fisiopathology - section of Radiotherapy; (2) S. Bortolo Hospital - Vicenza - Italy - General Surgery Department; (3) S. Bortolo Hospital - Vicenza - Italy - Medical Physics Department Firenze, Italy
Monte Carlo simulation for stereostatic treatment with multiple fields P2-36 Karl, Chan (1) ednesday 14/09/05 (1) Prince of Wales Hospital - Physics Department of Radiation Oncology W Shatin, Hong Kong
The study of dose enhancement close to platinum implants for 4, 8, 14 and 18 mm collimator helmets in the gamma knife surgery P2-37 Joel Y. C., Cheung (1); C.P., Yu (1); Robert TK, Ho (1) (1) Canossa Hospital - Gamma Knife Centre Hong Kong, Hong Kong
Stochastic target approximation by auto-computation of spatial units for stereotactic radiosurgery P2-38 Kyoung-Sik, Choi (1); Seongjong, Oh (2); Hyun-Tai, Chung (3); Moon-Chan, Kim (4); Bo-Young, Choe (5); Suh, Tae-Suk (6) (1) The Catholic University of Korea, School of Medicine - Biomedical Engineering College of Medicine; (2) The Catholic University of Korea, School of Medicine - Biomedical Engineering College of Medicine; (3) Seoul National University Hospital - Department of Neurosurgery; (4) Kangnam St. Mary's Hospital - Neurosurgery; (5) The Catholic University of Korea, School of Medicine - Biomedical Engineering College of Medicine; (6) The Catholic University of Korea, School of Medicine - Biomedical Engineering Seoul, Korea
64 Scientific Program
Comparison of dose calculations and dose measurements near heterogeneities in gamma knife radiosurgery P2-39 Françoise, Desmedt (1); Stéphane, Simon (2); Bruno, Vanderlinden (2); Christophe, Vandekerkhove (2); Thierry, Gevaert (1); Bob, Schaeken (3); Daniel, Devriendt (4); Nicolas, Massager (5); Marc, Levivier (1) (1) Hôpital Erasme - Centre Gamme Knife; (2) Institut J. Bordet - Physique; (3) AZ Middelheim - Physique; (4) Institut J. Bordet - Radiothérapie; (5) Hôpital Erasme - Neurochirurgie Brussels, Belgium
Dynamic arc: useful or expensive toy for meningiomas treatment? P2-40 Frederic, Dessy (1); Carine, Mitine (2); Laurent, Gilbeau (1); Marie-Therese, Hoornaert (1) (1) Hôpital de Jolimont - Radiotherapie; (2) Jolimont hospital - Radiotherapy Haine Saint Paul, Belgium
Simultaneous SRS for multiple intracranial lesions with single isocenter using micromultileaf collimator P2-41
Junichi, Fukada (1); Etsuo, Kunieda (1); Osamu, Kawaguchi (1); Satoshi, Seki (1); Naoyuki, Shigematsu (1); W 14/09/05
Minoru, Uematsu (1); Atsushi, Kubo (1) ednesday (1) Keio University - Department of Radiology Tokyo, Japan
A new tool for quantitative evaluation of plan quality in Fractionated Stereotactic Radiotherapy P2-42 Janna, Menhel (1); Dror, Alezra (1); Rafael, Pfeffer (1); Roberto, Spiegelmann (2) (1) Sheba Medical Center - Department of Oncology; (2) Sheba Medical Center - Department of Neurosurgery Ramat Gan, Israel
Characterization of lung lesion doses in Stereotactic Body Radiation Therapy (SBRT) via Monte Carlo P2-43 Premavathy, Rassiah (1); Martin, Fuss (2); Bill J., Salter (3) (1) UTHSC San Antonio - Radiology; (2) UTHSC San Antonio - Radiation Oncology; (3) Cancer Therapy & Research Center - Medical Physics San Antonio, USA
In SRS treatment what factors affect the normal tissues receiving doses much less than prescription doses? P2-44 Ramaswamy, Sadagopan (1); Narayan, Sahoo (2) (1) M.D. Anderson Cancer Center - Radiation Oncology; (2) M.D. Anderson Cancer Center - Radiation Physics Houston, USA
Dosimetric verification of an IMRS dose delivery of the Novalis system P2-45 Dong-Joon, Lee (1); Moon-Jun, Sohn (1); Sung Rok, Han (1); Sang Won, Yoon (1); Gee Taek, Yee (1); C. Jin, Whang (1) (1) Inje University - Ilsan Paik Hospital - Department of Neurosurgery Goyang, Korea 65 Scientific Program
Multiple isocentric plan with Brain Lab microMLC for eight brain mets P2-46 Dinesh, Tewatia (1); S.K., Rout (1) (1) Indraprastha Apollo Hospital - Medical Physics New Delhi, India
An analysis of the impact of intrafraction internal anatomy motion on delivery of radiation therapy: a dosimetry analysis using a dynamic phantom system P2-47 Chung, Jin-Beom (1); Suh, Tae-Suk (2); Chung, Won-Kyun (3) (1) The Catholic University of Korea, School of Medicine - Biomedical Engineering; (2) The Catholic University of Korea, School of Medicine - Biomedical Engineering; (3) Seoul Health College - Radiation Science Seoul, Korea
Dynamic field shaping arc versus circular cones for treatment of AVM: a comparative study P2-48 Carole, Gallez (1); Dirk, Verellen (2); Koen, Tournel (3); Nadine, Linthout (4); Tom, Wauters (5); Jean, D'Haens (6); Guy, Storme (7) (1) VUB - ETRO; (2) AZ VUB - Physique; (3) AZ-VUB - Radiotherapy; (4) AZ-VUB - Radiotherapy; (5) AZ-VUB - Radiotherapy; (6) AZ-VUB - Neurosurgery; (7) AZ VUB - Radiothérapie Brussels, Belgium ednesday 14/09/05 Gamma knife surgery for functioning pituitary adenomas W extending into cavernous sinus: Advantages in robotized micro-radiosurgery with advanced MR iImaging P2-49 Motohiro, Hayashi (1); Masahiro, Izawa (1); Taku, Ochiai (1); Koutaro, Nakaya (1); Tomokatsu, Hori (1); Kintomo, Takakura (1); Jean, Regis (2) (1) Tokyo Women's Medical University - Department of Neurosurgery; (2) CHU La Timone - Service de Neurochirurgie Tokyo, Japan
Efficacy of gamma knife radiosurgery in patients with recurrent or residual functioning and non functioning pituitary adenomas P2-50 Mercedes, Heureux (1); Bich-Ngoc-Thanh, Tang (2); David, Wikler (2); Nicolas, Massager (3); Marc, Levivier (4); Bernard, Corvilain (1) (1) Hôpital Erasme - Endocrinology; (2) Hôpital Erasme - PET Scan; (3) Hôpital Erasme - Neurochirurgie; (4) Hôpital Erasme - Centre Gamme Knife Brussels, Belgium
66 Scientific Program
Clinical results of LINAC-based stereotactic radiosurgery and Fractionated Stereotactic Radiotherapy for pituitary adenomas P2-51 Putipun, Puataweepong (1); Mantana, Dhanachai (1); Puangtong, Kraiphibul (1); Lucksana, Pochanugool (1); Somjai, Dangprasert (1); Jiraporn, Laothamatas (1); Veerasak, Theerapancharoen (2); Suchart, Phuthichjaroenrat (3); Pornpan, Yongvithisatid (1); Kanjana, Boonpitak (1) (1) Ramathibodi Hospital Mahidol University - Department of Radiology; (2) Ramathibodi Hospital Mahidol University - Department of Surgery; (3) Prasat Neurological Institute - Pathology Bangkok, Thailand
Gamma surgery in the treatment of nonsecretory pituitary macroadenomas P2-52 Jason, Sheehan (1); Ladislau, Steiner (2); Vincezo, Mingione (3); Edward R., Laws Jr. (1); Mary Lee, Vance (2); Chun-Po, Yen (2); Melita, Steiner (2); Matei, Stroila (2) (1) University of Virginia - Department of Neurosurgery; (2) University of Virginia - neurosurgery; (3) University of Vienna - Department of Neurosurgery Charlottesville, USA W
Results of steretoactic radiosurgery in patients with functional 14/09/05 pituitary adenomas P2-53 ednesday Fabiola, Flores Vazquez (1); Pomponio, Lujan Castilla (2); Fiacro, Jimenez-Ponce (3); Francisco, Velasco (4); Mario, Enriquez (5); Luis, García (6); Eduardo, Arana (7) (1) Hospital General de Mexico - Radiotherapy; (2) Hospital General de Mexico - Radiotherapy; (3) Hospital General de Mexico - Neurosurgery; (4) Hospital General de Mexico - Neurosurgery; (5) Hospital General de Mexico - Radiotherapy; (6) Hospital General de Mexico - Neurosurgery; (7) Hospital General de Mexico - Radiotherapy Mexico City, Mexico
Gamma knife radiosurgery for secretory and non-secretory pituitary adenomas P2-54 Aditya, Gupta (1); Sandeep, Vaishya (1); S S, Kale (1); V S, Mehta (1) (1) All India Institute of Medical Sciences - Neurosurgery Department New Delhi, India
The radiosurgery for nonfunctioning pituitary adenomas P2-55 Yoshiyasu, Iwai (1); Kazuhiro, Yamanaka (1); Katsunobu, Yoshioka (1) (1) Osaka City General Hospital - Department of Neurosurgery Osaka, Japan
LINAC stereotactic radiosurgery for pituitary adenomas P2-56 Martin, Malacek (1); Juraj, Steno (2); Ludmila, Trejbalova (3); Augustin, Durkovsky (4) (1) St. Elisabeth Cancer Institute - Department of Radiosurgery; (2) Faculty Hospital of the Comenius University - Department of Neurosurgery; (3) Faculty Hospital of the Comenius University - Department of Endocrinology; (4) St. Elisabeth Cancer Institute - Department of Radiology Bratislava, Slovakia
67 Scientific Program
Using a small diode detector for a quick quality assurance (QA) test of the Cyberknife system P2-57 Anthony K., Ho (1); Steven D., Chang (2); John R., Adler Jr. (3); Cristian, Cotrutz (4); Iris, Gibbs (5) (1) Stanford University - Radiation Oncology; (2) Stanford University - Neurosurgery; (3) Stanford University - Neurosurgery; (4) Stanford University - Radiation Oncology; (5) Stanford University - Radiation Oncology Stanford, USA
Influence of different inhomogeneities on the geometric distortion in stereotactic magnetic resonance imaging P2-58 Josef, Novotny Jr. (1); Josef, Vymazal (2); Pavel, Chuda (3); Dusan, Urgosik (4); Josef, Novotny (5); Roman, Liscak (6) (1) Na Homolce Hospital - Medical physics; (2) Na Homolce Hospital - Stereotactic and radiation neuro- surgery; (3) Na Homolce Hospital - Medical physics; (4) Na Homolce Hospital - Stereotactic and radiation neu- rosurgery; (5) Na Homolce Hospital - Medical physics; (6) Na Homolce Hospital - Stereotactic and radiation neurosurgery Prague, Czech Republic
Repositioning accuracy - evolution of a fractioned stereotactic system for the head and neck region P2-59 John, Way (1); Margaret, Schneider (2); Robert Ian, Smee (2); Lyn, Emanuel (2); Karl, Chan (1) (1) Prince of Wales Hospital - Physics Department of Radiation Oncology; (2) University of New South Wales - Prince of Wales Hospital - Department of Radiation Oncology ednesday 14/09/05 Shatin, Hong Kong W Applications of polymer gel dosimetry in stereotactic radiosurgery P2-60 Panagiotis, Papagiannis (1); Pantelis, Karaiskos (2); Loukas, Sakelliou (1); Panagiotis, Sandilos (2); Michael, Torrens (3) (1) University of Athens - Physics; (2) Hygeia Hospital - Medical Physics; (3) Hygeia Hospital - Gamma Knife Neurosurgery Department Athens, Greece
Radiosurgery for vertebral angioma. Steretactic body frame P2-61 Luis, Larrea (1); E, Lopez (1); J, Bea (1); M.C., Banos (1) (1) Hospital NISA Virgen del Consuelo - Oncologia Radioterapica Valencia, Spain
Dosimetric effect of intra-fraction motion during spinal radiosurgery P2-62 Martin, J Murphy (1); Cihat, Ozhasoglu (2); Warren, Kilby (3); Derek, Olender (3); (1) Virginia Commonwealth University, Richmond VA; (2) University of Pittsburgh PA; (3) Accuray Incorporated, Sunnyvale CA Richmond, USA
68 Scientific Program
Implementation of helical tomotherapy for spinal radiosurgery P2-63 John, Fiveash (1); Richard, Popple (2); Jennifer, De Los Santos (2); James, Markert (3); Barton L., Guthrie (4); Chris, Dobelbower (2) (1) University of Alabama at Birmingham - Radiation Oncology; (2) University of Alabama at Birmingham - Radiation Oncology; (3) University of Alabama at Birmingham - Department of Neurosurgery Birmingham, USA
Spinal radiosurgery: the consequences of “segmental image fusion technique” and its clinical experiences P2-64 Moon-Jun, Sohn (1); Dong-Joon, Lee (1); Yoon-Joon, Hwang (2); Sang-Ryong, Jeon (3); Ho-Yeon, Lee (4); Sang-Ho, Lee (5); C. Jin, Whang (1) (1) Inje University - Ilsan Paik Hospital - Department of Neurosurgery; (2) Inje University Ilsan Paik Hospital - Department of Neuroradiology; (3) Asan Medical Center, College of Medicine, University of Ulsan - Department of Neurosurgery; (4) Wooridul General Hospital - Department of Neurosurgery Goyang, Korea
Non-invasive radiological evaluation of superior cerebellar W
artery after gamma knife radiosurgery for idiopathic trigeminal 14/09/05 neuralgia: preliminary results of a cohort study P2-65 ednesday José, Lorenzoni (1); Philippe, David (2); Nicolas, Massager (3); Daniel, Devriendt (4); Françoise, Desmedt (1); Paul, Van Houtte (4); Jacques, Brotchi (3); Marc, Levivier (1) (1) Hôpital Erasme - Centre Gamme Knife; (2) Hôpital Erasme - Neuroradiologie; (3) Hôpital Erasme - Neurochirurgie; (4) Institut J. Bordet - Radiothérapie Brussels, Belgium
Stereotactic radiosurgery for trigeminal neuralgia using a non-dedicated linear accelerator P2-66 Salvador, Somaza (1) (1) La Floresta Medical Institute - Stereotactic Radiosurgery Unit Miami, USA
The complication rates after gamma knife radiosurgery for facial pain are predicted by pre-treatment Burchiel classification pain type: results from 256 gamma knife radiosurgery procedures P2-67 Thomas, Ellis (1); Volker W., Stieber (2); Stephen, Tatter (1); Alan, deGuzman (2); Kenneth, Ekstrand (2); Michael, Munley (2); Daniel, Bourland (2); Kevin, McMullen (2); William, Huang (2); Lovato, James (3); Christopher, Balamucki (4); Charles, Branch (1); Edward G., Shaw (2) (1) Wake Forest University School of Medicine - Department of Neurosurgery; (2) Wake Forest University School of Medicine - Department of Radiation Oncology; (3) Wake Forest University School of Medicine - Public Health Sciences; (4) Wake Forest University - School of Medicine Winston Salem, USA
69 Scientific Program
The success of gamma knife radiosurgery for facial pain varies by pre-treatment Burchiel classification pain type: results from 256 gamma knife radiosurgery procedures for trigeminal neuralgia P2-68 Volker W., Stieber (1); Thomas, Ellis (2); Alan, deGuzman (1); Edward G., Shaw (1); Charles, Branch (2); Daniel, Bourland (1); Kevin, McMullen (1); Christopher, Balamucki (3); Michael, Munley (1); Kenneth, Ekstrand (1); Lovato, James (4); William, Huang (1); Stephen, Tatter (2) (1) Wake Forest University School of Medicine - Department of Radiation Oncology; (2) Wake Forest University School of Medicine - Department of Neurosurgery; (3) Wake Forest University - School of Medicine; (4) Wake Forest University School of Medicine - Public Health Sciences Winston Salem, USA
ORAL SESSIONS 11h30 – 12h30
FUNCTIONAL RADIOSURGERY 1 OS16 Chairmen: Douglas, Kondziolka; Motohiro, Hayashi Room Nation
Radiosurgery of cavernous malformations associated OS16-1 with intractable seizures Yoshihisa, Kida (1) (1) Komaki City Hospital - Department of Neurosurgery ednesday
14/09/05 Komaki Aichi, Japan W
Gamma knife radiosurgical thalamotomy for essential tremor : OS16-2 a six year experience John, Lee (1); Joseph, Ong (2); Douglas, Kondziolka (3) (1) Hospital of the University of Pennsylvania - Neurosurgery; (2) University of Pittsburgh Medical Center - Department of Neurosurgery; (3) University of Pittsburgh Medical Center - Department of Neurological Surgery Philadelphia, USA
Gamma knife radiosurgery - an alternative for intractable OS16-3 mesial temporal lobe epilepsy Sujoy, Sanyal (1); V P, Singh (2); V S, Mehta (2) (1) All India Institute of Medical Sciences - Neurosurgery Department; (2) All India Institute of Medical Sciences - Neurosurgery Department Calcutta, India
70 Scientific Program
Does dose rate affect efficacy ? OS16-4 The outcomes of 256 gamma knife radiosurgery procedures for facial pain as they relate to the half-life of cobalt Christopher, Balamucki (1); Thomas, Ellis (2); Alan, deGuzman (3); Edward G., Shaw (3); Michael, Munley (3); Stephen, Tatter (2); Kenneth, Ekstrand (3); William, Huang (3); Daniel, Bourland (3); Kevin, McMullen (3); Charles, Branch (2); Lovato, James (4); Volker W., Stieber (3) (1) Wake Forest University - School of Medicine; (2) Wake Forest University School of Medicine - Department of Neurosurgery; (3) Wake Forest University School of Medicine - Department of Radiation Oncology; (4) Wake Forest University School of Medicine - Public Health Sciences Winston-Salem, USA
IMAGING - ARTERIOVENOUS MALFORMATIONS OS17 Chairmen: Philippe, David; Enrico, Motti Room Permeke & Rembrandt
Imaging development for dose planning of radiosurgery: OS17-1 Three dimensional MR (DRIVE) images and MR angiography W 14/09/05 Hiroshi K., Inoue (1) ednesday (1) Institute of Neural Organization - Restorative Neurosurgery Fujioka, Japan
Integration of three-dimensional corticospinal tractography OS17-2 into treatment planning for gamma knife radiosurgery Keisuke, Maruyama (1); Kyousuke, Kamada (1); Masahiro, Shin (1); Daisuke, Itoh (2); Shigeki, Aoki (4); Yoshitaka, Masutani (4); Masao, Tago (4); Takaaki, Kirino (1) (1) University of Tokyo Hospital - Department of Neurosurgery; (2) University of Tokyo Hospital - Radiology Tokyo, Japan
Target definition in radiosurgery of AVMs using digital OS17-3 subtraction angiography time series Harald, Treuer (1); Moritz, Hoevels (1); Stefan, Hunsche (1); Mohamad, Maarouf (1); Jürgen, Voges (1); Martin, Kocher (2); R.-P., Müller (6); V., Sturm (1) (1) University of Cologne - Department of Stereotaxy; (2) University of Cologne - Klinik für Strahlentherapie Köln, Germany
Stereotactic radiosurgery patient response: 3-phase diary study OS17-4 Janet, Williams (1); Robert, Smee (2) (1) University of New South Wales - Prince of Wales Hospital - Department of Radiation Oncology; (2) Prince of Wales Hospital - Department of Radiation Oncology Randwick, Australia
71 Scientific Program
EXTRACRANIAL RADIOSURGERY 1 OS18 Chairmen: David, Larson; John, Buatti Room Willumsen
A prospective trial on stereotactic radiotherapy OS18-1 of colo-rectal metastases Morten, Hoyer (1); Henrik, Roed (2); Anders, Traberg Hansen (1); Lars, Ohlhuis (2); Jorgen, Petersen (1); Hanne, Nellemann (3); Anne Kiil, Berthelsen (2); Cai, Grau (1); Sv. Aage, Engelholm (2); Hans, von der Maase (1) (1) Aarhus University Hospital - Department of Oncology; (2) Copenhagen University Hospital - Department of Oncology; (3) Aarhus University Hospital - Department of Diagnostic Radiology Aarhus C, Denmark
Stereotactic body radiation therapy of early stage non-small OS18-2 cell lung carcinoma: phase I study update Ronald, McGarry (1); Robert, Timmerman (2); Lech, Papiez (3); Mark, Williams (4) (1) Indiana University Medical Center - Department of Radiation Oncology; (2) University of Texas Southwestern - Department of Radiation Oncology; (3) Indiana University Medical Center - Department of Radiation Oncology; (4) Richard L. Roudebush V.A. Medical Center - Pulmonary Division Indianapolis, USA
Stereotactic radiotherapy for liver tumours based on MRI OS18-3 and tumor markers ednesday 14/09/05 Alejandra, Mendez Romero (1); Wouter, Wunderink (2); Shahid M, Hussain (3); Peter JCM, Nowak (4); Ben W JM, Heijmen (5); Joost, Nuyttens (6); Rene P, Brandwijk (7); Jan NM, Ijzermans (8); Peter C, Levendag (9) (1) Erasmus MC - Radiotherapy; (2) Erasmus MC - Radiotherapy; (3) Erasmus MC - Radiology; (4) Erasmus MC - Radiotherapy; (5) Erasmus MC - Radiotherapy; (6) Erasmus MC - Radiotherapy; (7) Erasmus MC - Radiotherapy; (8) Erasmus MC - Surgery; (9) Erasmus MC - Radiotherapy Rotterdam, The Netherlands
Stereotactic radiation treatment (SRT) for advanced OS18-4 intra-abdominal tumours Vincent, Vinh-Hung (1); Frederik, Vandenbroucke (2); Zsuzanna, B Nagy (1); Hilde, Van Parijs (1); Maria, Voordeckers (1); Jan, Van de Steene (1); Guy, Soete (1); Dirk, Van Den Berge (1); Johan, De Mey (2); Guy, Storme (1) (1) AZ VUB - Radiothérapie; (2) AZ VUB - Radiologie Brussels, Belgium
72 Scientific Program
SPONSORED SEMINAR 13h00 - 13h45
THE COMPLEMENTARY ROLE OF INTRA OPERATIVE MRI Room Nation AND RADIOSURGERY Seminar and lunch sponsored by Medtronic Chairman: Jacques Brotchi
ULB Erasme experience of treating patients with PoleStar and gamma knife Prof. J. Brotchi Hôpital Erasme - Neurochirurgie, Brussels, Belgium
Complementary Use of intra operative MRI technique and Radio Surgery Dr. M. Schulder New Jersey Medical School - Department of Neurosurgery, Newark NJ, USA
ORAL SESSIONS 14h00 - 15h00 W 14/09/05 ednesday FUNCTIONAL RADIOSURGERY 2 OS19 Chairmen: Douglas, Kondziolka; Motohiro, Hayashi Room Nation
Gamma knife radiosurgery to the pituitary for thalamic OS19-1 pain syndrome: clinical evaluation of recent our institutional series Motohiro, Hayashi (1); Takaomi, Taira (2); Taku, Ochiai (1); Mikhail, Chernov (1); Shinichi, Goto (2); Koutaro, Nakaya (1); Masahiro, Izawa (1); Tomokatsu, Hori (1) (1) Tokyo Women's Medical University - Department of Neurosurgery; (2) Tokyo Women's Medical Univeristy - Department of Neurosurgery Tokyo, Japan
Gamma knife radiosurgery for symptomatic trigeminal OS19-2 neuralgia. How should we select the treatment strategy ? Hiroyuki, Kenai (1); M, Yamashita (1); T, Nakamura (1); T, Asano (1); M, Saino (1); H, Nagatomi (1) (1) Nagatomi Hospital - Department of Neurosurgery Oita, Japan
Influence on pain outcome of the neurovascular compresion OS19-3 anatomy on MRI in patients with idiopathic trigeminal neuralgia treated by gamma knife radiosurgery José, Lorenzoni (1); Philippe, David (2); Nicolas, Massager (3); Daniel Salvador, Ruiz Gonzalez (4); Françoise, Desmedt (1); Jacques, Brotchi (3); Marc, Levivier (1) (1) Hôpital Erasme - Centre Gamme Knife; (2) Hôpital Erasme - Neuroradiologie; (3) Hôpital Erasme - Neurochirurgie; (4) Medica Sur SA de CV MSU 820125 T58 - Unidad Gamma Knife Brussels, Belgium 73 Scientific Program
Different targets in the gamma knife treatment OS19-4 for intractable pain Dusan, Urgosik (1); Roman, Liscak (2); Josef, Novotny Jr. (3); Josef, Vymazal (4); Vilibald, Vladyka (5) (1) Na Homolce Hospital - Stereotactic and radiation neurosurgery; (2) Na Homolce Hospital - Stereotactic and radiation neurosurgery; (3) Na Homolce Hospital - Medical physics; (4) Na Homolce Hospital - Stereotactic and radiation neurosurgery; (5) Na Homolce Hospital - Stereotactic and Radiation Neurosurgery Prague, Czech Republic
PHYSICS - NEWS OS20 Chairmen: Frank, Bova; Dirk, Verellen Room Permeke & Rembrandt
Image-guided and frameless localization in cranial stereotactic OS20-1 radiotherapy Joachim, Bogner (1); Beverly, Downes-Phillips (2); Dietmar, Georg (3); David W., Andrews (2) (1) Medical University Vienna - Radiotherapy and Radiobiology; (2) Jefferson Hospital for Neuroscience - Department of Neurosurgery; (3) Medical University Vienna - Radiotherapy and Radiobiology Vienna, Austria
Treatment of ocular melanoma; X-Knife treatment planning OS20-2 with optimal immobilization ednesday 14/09/05 Sandra, de Vries (1) W (1) Otago University - Radiation Therapy Dunedin, New Zealand
Initial experience with a x-ray based respiratory gating OS20-3 system for lung and liver Franz, Gum (1); Reinhard, Wurm (1); Armin, Fuerst (2); Volker, Budach (1) (1) Charité University Medicine Berlin - Department of Radiation Oncology; (2) BrainLAB - Radiotherapy Berlin, Germany
Evaluating the localization accuracy of 6D Fusion software OS20-4 for the Novalis body image guided system and its clinical application for spinal radiosurgery Jian-Yue, Jin (1); Samuel, Ryu (1); Jack, Rock (2); Kathleen, Faber (1); Marilyn, Gates (3); Shidong, Li (1); Benjamin, Movsas (1) (1) Henry Ford Hospital - Radiation Oncology; (2) Henry Ford Hospital - Neurosurgery Detroit, USA
74 Scientific Program
ORAL SESSIONS 15h00 - 16h00
FUNCTIONAL - TRIGEMINAL NEURALGIA 1 OS21 Chairmen: Joseph C.T., Chen; Jean, Régis Room Nation
Longterm clinical results for trigeminal neuralgia treated OS21-1 by gamma knife radiosurgery Murata Noriko Noriko, Murata (1); Manabu, Tamura (2); Jean, Regis (3) (1) Timone University Hospital - Stereotactic and Fonctional Neurosurgery; (2) Timone University Hospital - Stereotactic and Fonctional Neurosurgery; (3) CHU La Timone - Service de Neurochirurgie Marseille, France
Outcome of patients undergoing gamma knife stereotactic OS21-2 radiosurgery for medically refractory idiopathic trigeminal neuralgia
Kostas, Fountas (1); Joseph, Smith (2) W 14/09/05 (1) The Medical Center of Central Georgia - Department of Neurosurgery; (2) Medical College of Georgia - ednesday Neurosurgery Macon, USA
Outcomes of gamma knife radiosurgery in trigeminal neuralgia OS21-3 David, Huang (1); Danielle, Rudolph (2); Deane, Jacques (3) (1) Cancer Care Consultants/ Northridge Hospital - Radiation Oncology; (2) Independent CRA - CRA; (3) Good Samaritan Hospital - Neurosciences Institute Northridge, USA
Gamma knife radiosurgery as primary surgery for patients OS21-4 with trigeminal neuralgia John, Lee (1); Jae Gon, Moon (2); Ricky, Madhok (3); Brian, Jankowitz (2); Joseph, Ong (3); Douglas, Kondziolka (4); John C, Flickinger (6); L. Dade, Lunsford (6) (1) Hospital of the University of Pennsylvania - Neurosurgery; (2) University of Pittsburgh Medical Center - Neurosurgery; (3) University of Pittsburgh Medical Center - Department of Neurosurgery; (4) University of Pittsburgh Medical Center - Department of Neurological Surgery Philadelphia, USA
75 Scientific Program
PHYSICS - QUALITY ASSURANCE OS22 Chairmen: Stephan G, Scheib; Frank, Bova Room Permeke & Rembrandt
Using the Winston Lutz test and EPID to compare OS22-1 stereotactic radiosurgery set using Radionics LTLF and BrainLab Target Positioner Robert, Myers (1); Ryan, Smith (1); Michael, Dally (1) (1) The Alfred Hospital - Radiation Oncology Department Melbourne, Australia
Assessment of the geometric accuracy in stereotactic OS22 –2 PET image definition Josef, Novotny Jr. (1); Karel, Nechvil (2); Josef, Novotny (3); Roman, Liscak (4) (1) Na Homolce Hospital - Medical physics; (2) Na Homolce Hospital - Medical physics; (3) Na Homolce Hospital - Medical physics; (4) Na Homolce Hospital - Stereotactic and radiation neurosurgery Prague, Czech Republic
Quality assurance in stereotactic imaging using the known OS22-3 target point method Stefan G, Scheib (1); Stefano, Gianolini (2); Nicoletta, Lomax (1); Andreas, Mack (3) ednesday 14/09/05 (1) Klinik im Park - Gamma Knife Center; (2) Klinik im Park - Department of Medical Radiation Physics; (3) W Gamma Knife Center Frankfurt - Medical Physics Zürich, Switzerland
Quality assurance in stereotactic radiosurgery according OS22-4 E-DIN 6875-1 Stefan G, Scheib (1); Stefano, Gianolini (2); Nicoletta, Lomax (1) (1) Klinik im Park - Gamma Knife Center; (2) Klinik im Park - Department of Medical Radiation Physics Zürich, Switzerland
76 Scientific Program
ORAL SESSIONS 17h00 - 18h00
FUNCTIONAL - TRIGEMINAL NEURALGIA 2 OS23 Chairmen: Joseph C.T., Chen; Jean, Régis Room Nation
Incidence of paresthesias after radiosurgery (SRS) OS23-1 for trigeminal neuralgia targeting at the root entry zone Alessandra, Gorgulho (1); Antonio, De Salles (2); David, McArthur (3); Zachary, Smith (4); Leonardo, Frighetto (5); Carlos, Mattozo (1); Steve, Lee (6); Michael, Selch (7); Timothy, Solberg (7) (1) UCLA Medical Center - Department of Neurosurgery; (2) UCLA - Neurosurgery; (3) UCLA - Neurosurgery; (4) UCLA - Neurosurgery; (5) UCLA - Neurosurgery; (6) UCLA Medical Center - Department of Radiation Oncology Los Angeles, USA
Robotized micro-radiosurgery for essential trigeminal neuralgia: OS23-2
Evaluation and analysis of over 100 patients experience W 14/09/05 with unique method ednesday Motohiro, Hayashi (1); Taku, Ochiai (1); Masahiro, Izawa (1); Mikhail, Chernov (1); Koutaro, Nakaya (1); Tomokatsu, Hori (1); Kintomo, Takakura (1) (1) Tokyo Women's Medical University - Department of Neurosurgery Tokyo, Japan
Trigemina neuralgia treatment with linear accelerator OS23-3 radiosurgery: results in 82 patients Michael, Girvigian (1); Joseph CT, Chen (2) (1) Kaiser Permanente Medical Center - Department of Radiation Oncology; (2) Kaiser Permanente Medical Center - Neurosurgery Los Angeles, USA
Complication of gamma knife surgery for trigeminal neuralgia OS23-4 Shinji, Matsuda (1); Toru, Serizawa (2); Yoshinori, Higuchi (3); Makoto, Sato (4); Junichi, Ono (5) (1) Chiba Cardiovascular Center - Department of Neurology; (2) Chiba Cardiovascular Center - Department of Neurosurgery; (3) Chiba Cardiovascular Center - Department of Neurosurgery; (4) Chiba Cardiovasucular Center - Department of Radiology; (5) Chiba Cardiovascular Center - Department of Neurosurgery Chiba, Japan
77 Scientific Program
SPINE OS24 Chairmen: Iris, Gibbs; Antonio, DeSalles Room Permeke & Rembrandt
Single fraction spinal radiosurgery for the treatment OS24-1 of spinal metastases Peter, Gerszten (1); Steven, Burton (2); Cihat, Ozhasoglu (3); William, Vogel (3); Annette, Quinn (3); William, Welch (4) (1) Shadyside Hospital - Department of Neurosurgery; (2) Shadyside Hospital - Radiosurgery Department; (3) Shadyside Hospital - Radiation Oncology Department; (4) University of Pittsburgh Medical Center - Department of Neurological Surgery Pittsburgh, USA
Decade of Cyberknife at Stanford University 1994-2004 OS24-2 Iris, Gibbs (1); Anthony K., Ho (2); Cristian, Cotrutz (3); Steven D., Chang (4); Christopher, King (5); Albert, Koong (6); John R., Adler Jr. (7) (1) Stanford University - Radiation Oncology; (2) Stanford University - Radiation Oncology; (3) Stanford University - Radiation Oncology; (4) Stanford University - Neurosurgery; (5) Stanford University - Department of Radiation Oncology; (6) Stanford University - Radiation Oncology; (7) Stanford University - Neurosurgery Stanford, USA ednesday 14/09/05 Importance of image fusion for spinal radiosurgery OS24-3 W Antonio, De Salles (1); Alessandra, Gorgulho (1); Paul, Medin (2); Nzhde, Agazaryan (3); Timothy, Solberg (3); Carlos, Mattozo (3); Leonardo, Frighetto (3); Cynthia, Cabatan-Awang (3); Michael, Selch (3) (1) UCLA Medical Center - Department of Neurosurgery; (2) UCLA Medical Center - Department of Radiation Oncology Los Angeles, USA
Image-guided radiosurgery of the spinal nerve: OS24-4 A pilot study in swine Paul, Medin (1); Bryan William, Goss (2); Dennis, Chute (3); Antonio, De Salles (1) (1) UCLA Medical Center - Department of Radiation Oncology; (2) UCLA - Radiation Oncology; (3) UCLA - Pathology Los Angeles, USA
78 Scientific Program
Thursday 15/09/05
BREAKFAST SEMINARS 7h30 - 8h30
SPINAL STEREOTACTIC RADIOTHERAPY BS10 Room Rembrandt
Challenges in spinal radiosurgery BS10-1 Ingmar, Lax
Dosimetric effect of intra-fraction motion during BS10-2 spinal radiosurgery Martin J., Murphy
Evaluation of segmental image fusion in spine radiosurgery BS10-3 Moon-Jun, Sohn
VESTIBULAR SCHWANNOMAS HEARING PRESERVATION BS11 Room Permeke
Hearing preservation with gamma knife radiosurgery BS11-1 Seiji, Fukuoka Thursday 15/09/05 Hearing preservation with stereotactic radiotherapy BS11-2 Daniele, Rigamonti
Hearing preservation with Linac-based radiosurgery BS11-3 John, Suh
PITUITARY TUMORS: RADIOSURGERY OR RADIOTHERAPY? BS12 Room Willumsen
Respective role of radiosurgery and radiotherapy BS12-1 in non-secreting adenomas Idefumi, Jokura
Respective role of radiosurgery and radiotherapy BS12-2 in secreting adenomas Nicolas, Massager
Pituitary gamma knife radiosurgery BS12-3 Roman, Liscak 79 Scientific Program
PLENARY SESSION 8h45 - 10h00
PS4 Room Nation
DATA BLITZ UPDATE 5 PS4-1 Functional radiosurgery Douglas, Kondziolka
DATA BLITZ UPDATE 6 PS4-2 Spinal radiosurgery Iris, Gibbs
COMBINED STRATEGIES, TRIGEMINAL NEURALGIA, CANCEROGENESIS Chairmen: Douglas, Kondziolka; Iris, Gibbs
Combination therapy of intentional partial resection PS4-3 followed by gamma knife radiosurgery for large skull base meningiomas Seiji, Fukuoka (1) (1) Nakamura Memorial Hospital - Department of Neurosurgery Sapporo, Japan
Incidence of trigeminal nerve dysfunction after trigeminal PS4-4 neuralgia radiosurgery: a comparison between 3 treatment strategies Nicolas, Massager (1); Noriko, Tamura (2); Ouzi, Nissim (3); Daniel, Devriendt (4); Françoise, Desmedt (3); 15/09/05 Thursday David, Wikler (5); Jacques, Brotchi (1); Marc, Levivier (3); Jean, Regis (6) (1) Hôpital Erasme - Neurochirurgie; (2) CHU La Timone - Gamma Knife center; (3) Hôpital Erasme - Centre Gamme Knife; (4) Institut J. Bordet - Radiothérapie; (5) Hôpital Erasme - PET Scan; (6) CHU La Timone - Service de Neurochirurgie Brussels, Belgium
Estimating the risk of malignancy after radiosurgery PS4-5 in the general population Jeremy, Rowe (1); Alison, Grainger (1); Lee, Walton (2); Aurelia, Kollova (1); Matthias Walter Richard, Radatz (3); Andras A, Kemeny (1) (1) Royal Hallamshire Hospital - National Centre For Stereotactic Radiosurgery; (2) University of Sheffield - Department of Medical Physics and Clinical Engineering; (3) Royal Hallamshire Hospital - Department of Neurosurgery Sheffield, United Kingdom 80 Scientific Program
ORAL SESSIONS 10h30 - 11h30
ARTERIOVENOUS MALFORMATIONS 1 OS25 Chairmen: Douglas, Kondziolka; Keisuke, Maruyama Room Nation
Usefulness of time resolved MR digital substracted OS25-1 angiography (MRDSA) in the follow-up of cerebral arterio-venous malformations (AVMs) after gamma knife radiosurgery: preliminary results Philippe, David (1); Patrice, Jissendi (1); Isabelle, Delpierre (1); Danièle, Balériaux (1); Nicolas, Massager (2); Daniel, Devriendt (5); Marc, Levivier (5); Boris, Lubicz (1) (1) Hôpital Erasme - Neuroradiologie; (2) Hôpital Erasme - Centre Gamme Knife Brussels, Belgium
Clinical implications of the latent period after AVM OS25-2 radiosurgery Aurelia, Kollova (1); Farouq, Din (1); Alison, Grainger (1); Jeremy, Rowe (1); Lee, Walton (2); Matthias Walter Richard, Radatz (3); Andras A, Kemeny (1) (1) Royal Hallamshire Hospital - National Centre For Stereotactic Radiosurgery; (2) University of Sheffield - Department of Medical Physics and Clinical Engineering; (3) Royal Hallamshire Hospital - Department of Neurosurgery Sheffield, United Kingdom
The risk of hemorrhage after radiosurgery for cerebral OS25-3 Thursday 15/09/05 arteriovenous malformations: what is angiographic obliteration? Keisuke, Maruyama (1); Nobutaka, Kawahara (1); Masahiro, Shin (1); Masao, Tago (2); Hiroki, Kurita (3); Akio, Morita (1); Takaaki, Kirino (1) (1) University of Tokyo Hospital - Department of Neurosurgery; (2) University of Tokyo Hospital - Radiology; (3) Kyorin University Hospital - Department of Neurosurgery Tokyo, Japan
Gamma knife radiosurgery as an alterative treatment OS25-4 for dural AV fistulas involving the transverse-sigmoid sinus David Hung-Chi, Pan (1) (1) Taipei Veterans General Hospital - Department of Neurosurgery Taipei, Taiwan
81 Scientific Program
PITUITARY & CRANIOPHARYNGIOMAS OS26 Chairmen: Ajay,Niranjan; Jeremy, Ganz Room Permeke & Rembrandt
Gamma knife surgery and dopamine agonists in combination OS26-1 in the treatment of the clinical effects of prolactinomas Jeremy, Ganz (1); W A., Reda (1); Ayman, Hafez (1) (1) Cairo Nasser Institute - Gamma Knife Center Cairo, Egypt
Gamma knife radiosurgery for non-functioning pituitary OS26-2 adenomas Hidefumi, Jokura (1); Jun, Kawagishi (1); Hidetoshi, Ikeda (2); Kou, Takahashi (1); Teiji, Tominaga (3) (1) Furukawa Seiryo Hospital - Jiro Suzuki Memorial Gamma House; (2) Tohoku University - Department of Neurosurgery Furukawa, Japan
New treatment strategy for craniopharyngioma using OS26-3 gamma knife radiosurgery Tatsuya, Kobayashi (1); Yoshimasa, Mori (1); Yoshihisa, Kida (2); Toshinori, Hasegawa (3); Naoki, Hayashi (1) (1) Nagoya Kyoritsu Hospital - Gamma Knife Center; (2) Komaki City Hospital - Department of Neurosurgery Nagoya, Japan
Biochemical assessment and long-term monitoring in patients OS26-4 managed by radiosurgery for growth hormone secreting pituitary adenomas Ajay, Niranjan (1); Pramod Kumar, Pillai (2); L. Dade, Lunsford (3); Douglas, Kondziolka (3); Sue, Challinor (4); John C, Flickinger (3) 15/09/05 Thursday (1) University of Pittsburgh Medical Center - Neurological Surgery; (2) University of Pittsburgh Medical Center - Neurological Surgery; (3) University of Pittsburgh Medical Center - Department of Neurological Surgery; (4) University of Pittsburgh Medical Center - Division of Endocrinology and Metabolism Pittsburgh, USA
MOLECULAR IMAGING - PET OS27 Chairmen: David, Wikler; Josef, Novotny Jr. Room Willumsen
Trials to introduce the coordinate system on PET-CT image OS27-1 during dose planning in gamma knife surgery Naoki, Hayashi (1); Yoshimasa, Mori (1); Tatsuya, Kobayashi (1); Yuta, Shibamoto (2) (1) Nagoya Kyoritsu Hospital - Gamma Knife Center; (2) Nagoya City University - Department of Radiology and Radiation Oncology Nagoya, Japan 82 Scientific Program
PET 11C-methionine for gamma knife radiosurgery targeting OS27-2 of recurrent pituitary adenomas Bich-Ngoc-Thanh, Tang (1); Marc, Levivier (2); David, Wikler (1); Mercedes, Heureux (3); Nicolas, Massager (4); Daniel, Devriendt (5); Philippe, David (6); Bernard, Corvilain (4); Serge, Goldman (1) (1) Hôpital Erasme - PET Scan; (2) Hôpital Erasme - Centre Gamme Knife; (3) Hôpital Erasme - Endocrinology; (4) Hôpital Erasme - Neurochirurgie; (5) Institut J. Bordet - Radiothérapie; (6) Hôpital Erasme - Neuroradiologie Brussels, Belgium
Changes in amino-acid metabolism of pituitary adenomas OS27-3 following GK radiosurgery evaluated by PET-methionine Nicolas, Massager (1); Bich-Ngoc-Thanh, Tang (2); David, Wikler (2); Daniel, Devriendt (3); Françoise, Desmedt (4); Jacques, Brotchi (1); Serge, Goldman (2); Marc, Levivier (5) (1) Hôpital Erasme - Neurochirurgie; (2) Hôpital Erasme - PET Scan; (3) Institut J. Bordet - Radiothérapie; (4) Hôpital Erasme - Centre Gamme Knife Brussels, Belgium
Positron emission tomography target segmentation OS27-4 methodology for radiosurgery treatment planning David, Wikler (1); Bich-Ngoc-Thanh, Tang (1); Daniel, Devriendt (2); Marc, Levivier (3); Serge, Goldman (1) (1) Hôpital Erasme - PET Scan; ( 2 ) Institut J. Bordet - Radiothérapie; ( 3 ) Hôpital Erasme - Center Gamme Knife Brussels, Belgium Thursday ORAL SESSIONS 11h30 - 12h30 15/09/05
ARTERIOVENOUS MALFORMATIONS 2 OS28 Chairmen: Serge, Blond; Christer, Linquist Room Nation
Long-term follow-up of quality of life after gamma knife OS28-1 radiosurgery treatment for Arteriovenous Malformations Michael, Musacchio (1); Brian, Kuchay (1); Nimesh, Patel (1); Bradley, Bagan (1); Sepehr, Sani (1); Demetrius, Lopes (1) (1) Rush University Medical Center - Neurosurgery Chicago, USA
Novalis® based radiosurgical treatment of AVMs. OS28-2 Our pre-eliminary results Recai, Ates (1); Maarten, Moens (1); Katrijn, Van Rompaey (1); Luc, Cavens (1); Cristo, Chaskis (1); Dirk, Vandenberge (2); Jean, D'Haens (1) (1) AZ VUB - Neurochirurgie; (2) AZ VUB - Radiothérapie Brussels, Belgium
83 Scientific Program
Clinical outcomes following gamma knife radiosurgery OS28-3 for arteriovenous malformations of the brain Sait, Sirin (1); Kaan, Oysul (2); Hulya, Sirin (2); Asli, Oysul (2); John C, Flickinger (1); Douglas, Kondziolka (1); L. Dade, Lunsford (1) (1) University of Pittsburgh Medical Center - Department of Neurological Surgery; (2) University of Pittsburgh Medical Center - Department of Radiation Oncology Pittsburgh, USA
Radiosurgery of cerebral arteriovenous malformations OS28-4 in the paediatric age group. About a series of 100 patients Nicolas, Reyns (1); Serge, Blond (1); G, Touzet (1); B, Coche (1); J.Y., Gauvrit (1); J.P., Pruvo (1); P, Dhellemmes (1) (1) Centre Hospitalier Régional et Universitaire de Lille - Centre Gamma Knife Lille, France
Neurological deficit rather than obliteration determines OS28-5 quality of life in patients treated with radiosurgery for AVMs Meera, Ramani (1); Yuri, Souza (2); Deirdre, Dawson (3); Daryl, Scora (4); May, Tsao (5); Michael, Schwartz (6) (1) University of Toronto - Division of Neurosurgery; (2) University of Toronto - Division of Neurosurgery; (3) University of Toronto - Psychology; (4) University of Toronto - Medical Physics; (5) University of Toronto - Radiation Oncology; (6) Sunnybrook Hospital - Neurosurgery Department Toronto, Canada
EXTRACRANIAL RADIOSURGERY 2 OS29 Chairmen: Morten,Hoyer; Gabriela, Simonova Room Permeke & Rembrandt
Stereotactic radiosurger y after external radiotherapy OS29-1 for nasopharynx carcinoma 15/09/05 Thursday Selcuk, Peker (1); Beste Melek, Atasoy (2); Meric, Sengoz (2); Ufuk, Abacioglu (2); Turker, Kilic (1); Necmettin, Pamir (1) (1) Marmara University School of Medicine - Department of Neurosurgery; (2) Marmara University - Radiation Oncology Istanbul, Turkey
Image guided conformation arc radiosurgery for prostate OS29-2 cancer: early clinical results Guy, Soete (1); Dirk, Verellen (2) (1) AZ VUB - Radiothérapie; (2) AZ VUB - Physique Brussels, Belgium
84 Scientific Program
PET predicts treatment failure of extracranial stereotactic OS29-3 radiosurgery before CT Volker W., Stieber (1); William, Kearns (1); William, Hinson (1) (1) Wake Forest University School of Medicine - Department of Radiation Oncology Winston Salem, USA
How can tumor effect and normal tissue effect be balanced OS29-4 in stereotactic body radiotherapy Wolfgang, Tome (1); John, Fenwick (1); Jack, Fowler (1); Minesh, Mehta (1) (1) University of Wisconsin Medical School - Human Oncology Department Madison, USA
IMAGING 2 OS30 Chairmen: John, Flickinger; Michael, McDermott Room Willumsen
How much does the addition of stereotactic T2 images OS30-1 affect tumor definition and treatment plans for acoustic schwannoma radiosurgery? John, Flickinger (1); Douglas, Kondziolka (2); Ajay, Niranjan (3); Ann H., Maitz (4); L. Dade, Lunsford (2) (1) University of Pittsburgh Medical Center - Department of Radiation Oncology; (2) University of Pittsburgh Medical Center - Department of Neurological Surgery; (3) University of Pittsburgh Medical Center - Neurological Surgery; (4) University of Pittsburgh Medical Center - Image Guided Neurosurgery Pittsburgh, USA Thursday 15/09/05 A CT scan and anatomical cadaveric study of the OS30-2 pterygopalatine ganglion for use in gamma knife treatment of Cluster Headache William, Olivero (1); Jorge, Alvernia (2); Dan, Spomar (3) (1) OSF Saint Francis Medical Center - Department of Neurosurgery; (2) University of Illinois - Neurosurgery; (3) University of Illinois - Neurosurgery Peoria, USA
Assessment of post-radiosurgical imaging studies: OS30-3 a volumetric algorithm and an estimation of its error Jason, Sheehan (1); John, Snell (2); Matei, Stroila (3); Ladislau, Steiner (1) (1) University of Virginia - Department of Neurosurgery; (2) University of Virginia - Lars Leksell Center for Gamma Knife Radiosurgery; (3) University of Virginia - neurosurgery Charlottesville, USA
Meningiomas after radiosurgery: OS30-4 When is recurrence expectable? Roberto, Spiegelmann (1); Janna, Menhel (2); Rafael, Pfeffer (2); Dror, Alezra (2) (1) Sheba Medical Center - Department of Neurosurgery; (2) Sheba Medical Center - Department of Oncology Ramat Gan, Israel 85 Scientific Program & Oral Presentations
CLOSING SESSION 12h30 - 13h30
2005 RECIPIENT OF THE JACOB I. FABRIKANT AWARD Room Nation Radiosurgery of arteriovenous malformations : evoluation of the technique Federico, Colombo Vincenza, Italy
YOUNG NEUROSURGEON AWARD, BEST POSTER AWARD, LOTTERY, CLOSING REMARKS 15/09/05 Thursday
86 Exhibition
Description
Companies display their products and services in the exhibition on the 2nd floor, where the lunches and coffee breaks are organized.
Exhibition Opening Hours Sunday Sept. 11, 2005 16h30 - 20h30 Monday Sept. 12, 2005 08h30 - 18h00 Tuesday Sept. 13, 2005 08h30 - 13h00 Wednesday Sept. 14, 2005 08h30 - 18h00 Thursday Sept. 15, 2005 08h30 - 14h00
87 Exhibition
Floorplan & List of Exhibitors
Exhibition map
88
Exhibition
Exhibitors List by alphabetical order
5 3D Line Medical Systems s.r.l. 13 Accuray 4 Alcis & Neuropace 15 American Radiosurgery 12 BrainLAB O Carl Zeiss Surgical GmBH 19 Dixi Medical / BioScan 11 Elekta 10B Foundation Against Cancer, Belgium 9 IBA Particle Therapy 1 inomed Medizintechnik GmBH 3 Medical Intelligence 18 Medtronic 10 Nomos Radiation Oncology - A Division of North American Scientific 2 Orfit industries NV 7 Philips 14 PTGR - Gmbh 8 Radionics, a Division of Tyco Healthcare Belgium N.V. 16 Siemens 17 TomoTherapy incorporated 6 Varian Medical Systems
89 Sponsors & Exhibitors Activities
The Organizers of the 7th ISRS Congress gratefully acknowledge the support of the following companies (listed by alphabetical order) : 3D Line Medical Systems s.r.l. 3D Line Medical Systems S.r.l. is active in the fields of Radiotherapy, Radiosurgery, Medical Physics and Neurosurgery with user- and patient-friendly innovations. Via Bernardo Rucellai 23 20126 Milan Italy www.3dline.com
Accuray The CyberKnife® Stereotactic Radiosurgery System is a non-invasive, 100% frameless, image-guided radiosurgery system that can ablate tumors and other lesions anywhere in the body without open surgery. It is the only system that integrates real time image-guidance and robotic delivery of radiation to deliver proven sub-millimeter total clinical accuracy. Tour Ariane 33e 5 Place de la Pyramide 92088 Paris La Défense Cedex France www.accuray.com Alcis & Neuropace ALCIS is an independent French company which develops and markets functional and stereotactic neurosurgery devices and instruments (Depth electrodes, stereotactic frame, percutaneous screws for stereotactic frame re-positioning). Chemin de Palente 8A 25000 Besançon France www.alcis.net American Radiosurgery American Radiosurgery, Inc, booth 15, presents the GammaART 6000™ Rotational Gamma System (RGS) for Radiosurgery, the EXPLORER-4D™ treatment planning system, and the newly released automatic head positioner. The RGS is produced exclusively in the United States. 16776 Bernardo Center Dr., # 203 San Diego, California USA 92128 www.radiosurgery.net
90 Sponsors & Exhibitors Activities
Amersham GE Healthcare GE Healthcare provides expertise in medical imaging which is dedicated to detecting disease earlier and tailoring individual treatment. More than 42,500 employees are committed to serving healthcare professionals and their patients in more than 100 countries. Kouterveldstraat 20B B-1831 Diegem Belgium www.gehealthcare.com
BioScan BioScan offers the last generation of real-time dynamic digital X and gamma rays imaging systems for low dose filmless diagnostic, interventional radiology, stereotactic radiosurgery, radiotherapy applications and non-destructive testing (NDT). 27, rue Pré Bouvier 1217 Meyrin/Geneva Switzerland www.bioscan.ch
BrainLAB BrainLAB is the leader in SRS solutions for cranial and extracranial indications. Our state-of- the-art products include Novalis Shaped Beam Surgery, m3 micro-MLC, xacTrac X-Ray with Adaptive Gating, and iPlan TPS. Ammerthalstrasse 8 85551 Heimstetten Germany www.brainlab.com
Carl Zeiss Surgical GmBH Radiation Dose Directly to the Target. INTRABEAM® is a complete proven system for the delivery of intraoperative radiation therapy (IORT) to tumors and tumor beds following re- section. For more information please contact: Carl Zeiss-strasse 73446 Oberkochen Germany www.zeiss.de/radiotherapy
91 Sponsors & Exhibitors Activities
Codali - Guebert Contrast for Life Rue Henri Dunant 31 1140 Brussels Belgium www.codali.be Dixi medical For over 20 years, we have developed and marketed a full range of electrodes and instru- ments intended to functional and stereotactic neurosurgery. We offer quality tools which perfectly suit the evolution of surgical techniques. 4 Chemin de Palente, BP 889 25025 Besançon France www.diximedical.com
Elekta Fighting serious disease Elekta is an international medical-technology Group, developing the world’s most advanced clinical solutions for high precision radiation treatment of cancer and for non- or minimally invasive treatment of brain disorders. Kungsstensgatan 18 - Box 7593 103 93 Stockholm Sweden www.elekta.com
Foundation Against Cancer, Belgium The Foundation against Cancer encourages the development of new radiotherapeutic approaches allowing more efficient and beneficial therapies. Chaussée de Louvain 479 Leuvensesteenweg 1030 Brussels Belgium www.cancer.be
92 Sponsors & Exhibitors Activities
IBA Particle Therapy IBA PARTICLE THERAPY is at the leading edge of technology in the fields of cancer diagno- sis and therapy. IBA PARTICLE THERAPY also offers innovative solutions ensuring the well- being, health and safety of many of our daily actions. It is listed on the pan-European stock exchange EURONEXT and is integrated into the NextEconomy market segment and belongs to BelSmall index. Avenue A. Einstein, 9 1348 Louvain-la-Neuve Belgium www.iba-worldwide.com Inomed Medizintechnik GmBH Inomed creates innovative products and Systems for Neuromonitoring, from the tailor-made probe and electrodes to the complete neuromonitoring system. Tullastrasse 5a 79331 Teningen Germany www.inomed.com S. Karger AG S. Karger AG is a leading international publisher of books and journals primarily in the basic and medical sciences. The largest medical and scientific publisher in Switzerland, Karger pro- duces 73 international specialty journals and approximately 60 yearly book titles covering all fields of research and practice. Medical and Scientific Publishers Allschwilerstrasse 10 4009 Basel Switzerland www.karger.com Medical Intelligence Medical Intelligence is a world leading supplier of innovative Radiation Oncology and inter- ventional guidance products for precise patient positioning and treatment. Our product lines include non-invasive immobilization systems and 6D robotic devices. Feyerabendstrasse 13 - 15 86830 Schwabmünchen Germany www.medint.de
93 Sponsors & Exhibitors Activities
Medtronic Medtronic is the world leader in medical technology providing lifelong solutions for people with chronic disease. Each year, 5 million patients benefit from Medtronic's technology. Route du Molliau 31 1131 Tolochenaz Switzerland www.stealthstation.com
Nomos Radiation Oncology - A Division of North American Scientific North American Scientific is manufacturing IMRT (PEACOCK® and CORVUS) and IGRT, (BAT and nTRAK(tm)) products and brachytherapy seeds (Prospera®). Over 500 sites worldwide are equipped with the Company's clinically proven products. A Division of North American Scientific Pastoor Cramerstraat 2 h6102 AC Echt The Netherlands www.nasmedical.com Orfit Industries NV Orfit Industries develops and produces thermoplastic materials for immobilization and fixa- tion purposes in medical applications. Vosveld 9a 2110 Wijnegem Belgium www.orfit.com Pfizer Partner for Better Health. Boulevard de la Plaine, 17, Pleinlaan 1050 Brussels Belgium www.pfizer.be
94 Sponsors & Exhibitors Activities
Philips Philips Radiation Oncology systems provide innovative solutions to manage patient treat- ment. These include imaging, localization, simulation and planning, miminally invasive, image-guided procedures and inverse planning, conformal external beam planning and IMRT. For more information : Philips Medical Systems Rue des Deux Gares 80 1070 Brussels Belgium www.medical.philips.com PTGR - GmbH A main focus of the activities of our company lies in the field of quality assurance in radio- surgery and stereotactic radiotherapy (RS, SRT, ISRS, ISRT) bearing in mind the new guide- line E-DIN 6875-1. PTGR-GmbH Eduard-Spranger Str. 27/2 72076 Tuebingen Germany www.ptgr.de Radionics, a Division of Tyco Healthcare Belgium N.V. Throughout the medical community, Radionics is synonymous with trusted accuracy. Radionics offers stereotactic radiotherapy technologies, including HDRT(tm)and XKnife(tm) systems, providing complete solutions for cranial, head, neck and body treatments. A division of Tyco Healthcare Belgium N.V. Koningin Elisabethlaan 45 9000 Gent Belgium www.radionics.com Schering As a successful pharmaceutical company. We develop drugs of high medical value so as to continuously improve the quality of life. We focus on our four strategic Business Areas: Gynecology & Andrology, Oncology and Diagnostic Imaging. J.E.Mommaertslaan, 14 1831 Diegem (Machelen) Belgium www.schering.be
95 Sponsors & Exhibitors Activities
Siemens Medical Solutions Siemens Medical Solutions - Oncology Care Systems - Your partner for treating tumors aggressively and patients gently. With leading-edge solutions that seamlessly connect the entire continuum of oncology care. Allowing you to make earlier diagnoses, deliver more aggressive therapies, and manage the entire process. Oncology Care Systems 4040 Nelson Avenue Concord, CA 94520 USA. www.SiemensMedical.com/oncology TomoTherapy Incorporated TomoTherapy's technology uniquely combines helical IMRT/IMRS with CT imaging for unsur- passed conformality and setup accuracy. TomoTherapy now offers the world's first Adaptive Planning module to ensure your prescription is met. 1240 Deming Way Madison, WI 53717 USA www.tomotherapy.com Varian Medical Systems Varian Surgical Sciences produces leading-edge tools for planning and delivering image- guided Radiosurgery. The company’s technologies encompass solutions for delivering both framed and frameless cranial and spinal IGRS treatments, using either multileaf collimators or cones. Varian Medical Systems International AG Chollerstrasse 38 6303 Zug Switzerland www.varian.com
96 Congress Social Program
Are you interested in one of the following activities and not yet registered? Come and visit us at the registration desks (ground floor).
Opening Ceremony & Welcome Reception
Sunday 11 September 2005, 17h00
Sheraton Hotel, 2nd floor, meeting room Nation
Ceremony, 17h00 - 18h00 Welcome Speeches : Prof. Marc Levivier (chair of the congress) Prof. Jean Regis (president of the scientific committee) Prof. Douglas Kondziolka (ISRS president) Prof. Jacques Brotchi (honorary chairman of the congress) Followed by a lecture by Philippe Busquin (European Deputy and Former European Commissioner for Research): "The EU competitiveness and the socio-economic challenges of radiosurgery".
Reception, 18h00 - 20h00, exhibition Official opening of the ISRS 2005 exhibition, walking cocktail and reception with all the participants and officials. The participation to this ceremony and to the reception is included in the registration fee. Although booking was highly recommended through the registration form, seats in the meeting room Nation will be subject to availability. The ceremony will be broadcasted on plasma screens in the exhibition. Participants are advised that they have to wear their badge at this event.
Gala Dinner & Concert of Toots Thielemans
Wednesday 14 September 2005, 19h30
Plaza Theater, Boulevard Adolphe Max, 126-128, 1000 Brussels The Theater is next to the Hotel Plaza and belongs to the same building. It is located very close to the Sheraton: a short walk of 3 minutes is sufficient to reach the venue. Build in 1930 in a unique Spanish-Arab-Moorish style. The theatre was restored in 1996 with the absolute decision to keep the original boxes, the genuine bracket-lamps, the stage, the rich sculptured wall ornaments as well as the graceful arches and fake balconies in Arab and Baroque styles. 97 Congress Social Program
This special evening will be composed of a welcome cocktail Photographer © Jos Knaepen and a sitting dinner in this magical place. During the dinner, a unique and exceptional concert will be held by the world famous harmonica jazzman Toots Thielemans.
Awards to be received at the closing session of Thursday will be announced during the gala dinner.
Members of the Quartet : Jean Toots Thielemans Lead Bert Van Den Brink Keyboard Bart De Nolf Contrabas Hans Van Oosterhout Drums This outstanding evening is supported by a grant from Belgacom. Price: A fee of 90 E (VAT included) is applied. Booking is compulsory. The nominative vouchers for pre-bookings for this evening as well as further infor- mation have been distributed together with the badge. If you are not yet registered, please come at the registration desk on Monday September 12, 2005 : a limited number of vouchers may still be available. Participants are advised to bring their voucher and badge at this event.
Program 19h30 Cocktail reception in the theater foyer 20h00 Open Doors 20h15 - 21h40 Dinner 21h45 - 22h30 “Toots Thielemans Quartet” 22h30 Dessert and Coffee
98 Tours & Accompanying Persons Program
Booking Instructions
The following tours have been proposed for the ISRS 2005 Congress. They include profes- sional guides as well as transportation and are designed to provide a memorable and com- fortable visit.
The departure will be organized from the meeting point in the congress venue (ground floor of the Sheraton hotel).
These tours have been pre-sold to participants and accompanying persons. However, a lim- ited number of tours will be available at the tour desk in the registration area (ground floor).
For delegates who have already registered, ICEO sent a written confirmation of selected tours.
Program Overview
Day Activity Date Price Sunday Brussels at a Glance 11/09/05 pm 33,25 E Monday Bruges 12/09/05 all day 110,00 E Tuesday Brussels at a Glance 13/09/05 pm 33,25 E Wednesday Antwerp 14/09/05 all day 113,30 E
All the tours proposed are offered on a first come first served basis. In case the minimum number of participants is not reached, the organisers reserve the right to cancel or modify the tours. Please contact the tours desk for an update of the program. Prices are including belgian VAT 21 %.
Description of the Tours
The program and its content may be subject to slight changes. Please visit us at the tours desk in order to receive the detailed program, visits & schedule.
Brussels This city tour gives a good overview of the city's evolution. It includes historical and current attractions as well as an introduction to the typical and popular sights of Belgian culture. Date Sunday, September 11, 2005 - Afternoon or Tuesday, September 13, 2005 - Afternoon 99 Tours & Accompanying Persons Program
Program 12h00 Meeting at the congress meeting point (ground floor) with your guide- lecturer and coach departs for city tour. By coach : Place Royale, Parc Royal (18th century), Palace of Justice (first part of 19th century), Avenue Louise, Horta House,- Cinquantenaire (end of 19th century), Walking tour of the Grand'Place, which is the birth place of Brussels in the early Middle Ages. During the guided tour you will get a overview of typical Belgian architecture (Gothic and Baroque), products (chocolate, lace, glasswork, tapestries, altar pieces,...) and popular characters (Manneken Pis, Tintin, Toone,...). ± 15h00 End of the tour. Price 33,25 E per person. The price includes Transport by coach, conference visit with multilingual guide in History, extra guide depending on the number for the walking tour, taxes coor- dination and services.
Bruges A stroll along the waters of the Minnewater, the canals, the white swans, the little white houses in the Beguinage. Here in Bruges, everything is poetry, romance and indefinable melancholy. Join us for a guided tour of a part of Bruges that few visitors take the time to discover: the city of the Hanseatic merchants who sell spices from the Orient, wines from the Rhine, furs from Russia. In the bustle of the docks you will find an atmosphere as cos- mopolitan as it was in the 16th century city : the largest port in the world ! Date Monday, September 12, 2005 - 1 day Program 08h45 Meeting at the congress meeting point (ground floor), departure with your guide in the city center. Arrival at Bruges and beginning of the tour. Town Hall, Holy Blood, Basilica, St Jean Hospital Church of Our Lady, Begijnhof,... Lunch. Continuation of the visit. Boat trip. End of the visit and free time. Departure. ± 17h00 Arrival in Brussels. Price 110 E per person. 100 Tours & Accompanying Persons Program
The price includes Coach transport, accompaniment and guided conference visits with multilingual guide, lunch (starter, main course, dessert, drinks), entrance fees, tips, taxes, reservation and coordination services.
Antwerp Belgium's 2nd city, Antwerp, is known as one of the largest ports in Europe which, over the centuries, became fabulously rich thanks to the commerce with distant countries. Antwerp is also an artistic centre. In addition, since the 15th century, it has been the largest diamond centre in the world with a worldwide reputation. Date Wednesday, September 14, 2005 - 1 day Program 08h45 Meeting with our guide at the congress meeting point (ground floor). Departure by coach. Introduction to the day’s theme. Arrival in Antwerp passing by the Jewish neighbourhood which is also the diamond centre. Visit of a diamond center, which will give you information about the different types of diamonds and methods of cut- ting in the world. Visit to the Cathedral. Lunch. Walk around the historical heart of the city : Town Hall, Corporations House, Rockox House, Saint Charles Borromée and Notre Dame,... Departure by coach to Brussels through the port or the Art Nouveau area. ± 16h00 Arrival to Brussels. Price 113,30 E per person. The price includes Transport by coach, accompaniment and guided conference visits with a multilingual guide, extra guides following number of persons, entrances, lunch (drinks included: 2 glasses of wine or beer and coffee, water), tips, taxes, reservation and coordination services.
101 About Brussels
City Description
In the capital of Europe, art-lovers can happily move around in their element. Art is very much in evidence here and always full of life. It occupies an extremely important place in the city, from its most classical forms of expression through to waves of avant-garde. Not to mention its well-known gems of surrealism and comic strip. Music-lovers are also spoilt for choice between famous symphony orchestras and the ever-inventive jazz; rock or world music bands.
From magnificent façades to strange buildings: although very much attached to its rich royal tradition, there is no uniform look to the city, either as a shrine to period architecture or as a futuristic megalopolis, accented here and there by countless Art Nouveau gems. Yet it’s also true that there’s “a little of all that” in Brussels. And many more treasures besides, some very much on show, others almost hidden away. But never inaccessible. Because the real ambassadors of the capital are, of course, the inhabitants themselves.
The national languages in Belgium are French, Dutch (Flemish) and German. In Brussels, French is more commonly used and Flemish is understood by almost everyone. As the cap- ital of Europe, English is of course often used and understood.
Touristic information At the registration area on the ground floor, a hostess from the Brussels Tourism Office will help you with any question regarding the city and its surroundings. Brochures are at your disposal at the same desk.
Climate
The weather in Brussels is a continental one. In summer, the weather is usually warm and dry. But who knows ? This time it may not be the case, so provide you with warm clothes and an umbrella in the case of rain showers. For more information about the weather forecast, have a look at the website : www.meteo.be
102 About Brussels
Credit Card & Currency Exchange
Major credit cards (VISA, American Express and MasterCard) are accepted in most shops, hotels and restaurants in Brussels. Automatic teller machines can be found in all parts of the city and cash withdrawals may be made using your credit card. The logos of accepted cards are shown on the machine. The currency of Belgium is the Euro E. Follow this conversion table in order to get an idea of exchange rates (information only, subject to changes).
Exchange Rates (1 E) (information only, subjected to change - made on August 30th, 2005) 1$ (USD) 1£ (GBP) 1Yen (JPY) 0,8195 E 1,4641 E 0,7364 E
In case of the loss or theft of your credit card, please call the following numbers (national numbers): Visa 24h/24h +32 (0) 70/344 344 Mastercard/Eurocard 24h/24h +32 (0) 70/344 344 American Express 24h/24h +32 (0) 2/676 26 26
Electricity
Electricity is supplied at 220V.
Restaurants and Places to Be
Belgium is well known for the quality of the food ! You will find a list of restaurants, bars and clubs in the “After Hours” guide available in your bag or better ask the tourist desk of the organisers for an good advise. Tipping is not obligatory as service and value-added tax (VAT) are included in hotel and restaurant prices. But if you're pleased with the service, add a little extra.
Shops Opening Hours
The banks open from Monday to Friday, 9h00-16h00. They close later on Friday. Some of them are open on Saturday morning. Post offices usually open from 9h00-12h00 and from 14h00-16h00 or from 9h00-17h00 in big shopping malls. 103 About Brussels
Most of the shops open from 9h00/10h00 and close around 18h00/19h00. Some big shop- ping centers are open until 20h00, 21h00 on Friday. In Brussels, the shops are closed on Sunday. However, some shops near the Grand Place and the night shops are open.
Telephones/Fax & Useful Numbers
Public telephones may be found on the 3rd floor of the Sheraton Hotel. Credit call cards can be purchased from any newsagent in the city. A business center, where you can send fax, is situated in front of the reception desk of the hotel.
Nearest pharmacy Rue du Progrès 29, Brussels +32 (0) 2/203 67 29 Duty pharmacy Pharmacie Rue de Louvain +32 (0) 2/511 32 93 Nearest Hospital Clinique Saint-Jean Boulevard du Jardin Botanique 32 1000 Brussels Phone : +32 (0) 2/221 91 11 Fax: +32 (0) 2/219 14 92 Police 101 (national call) Card stop (credit card lost or stolen) +32 (0) 70/344 344 Ambulances (transportation) +32 (0) 2/649 50 10 National Information Service in English 1405 in French 1307 in Dutch 1207 Taxis +32 (0) 2/349 49 49 STIB (www.stib.be) 0900 10 310 (national call) : local transportation SNCB (www.b-rail.be) +32 (0) 2/528 28 28 : train transportation Brussels Airport 0900 7 0000 (national call)
Transportation
The congress is organized right in the city center of Brussels ! Therefore, most of the places in the center are at walking distance. For any question, please ask the Registration area/Touristic desk. 104 About Brussels
Access by Train The nearest railway station is Brussels North (walking distance 8 minutes). There are daily international trains leaving from Brussels Midi to Amsterdam, Frankfurt, London, Paris, etc. Brussels Midi is located in the South of Brussels. For further information on timetables and availabilities of the trains, check the following website: www.b-rail.be To reach another place in Brussels, please be advised that transportation in the city itself is easiest by metro, tram, bus or taxi.
In the city by tram and metro From the Gare du Midi Metro station to go to the congress venue, you can take the metro line 2 direction Simonis and stop at Rogier Station. From the congress venue to the opposite side of the city center, you can take the trams num- ber 52, 55, 56, 81 or 3, direction Gare du Midi/ Zuidstation or Churchill. For further infor- mation on the Brussels public transportations by tram and metro, check the following web- site www.stib.be or at the information desks in most of the metro station.
In the city by taxi Taxis (metered) are available at the Rogier Place. If you need to order a taxi please contact the concierge at the Sheraton, he can answer your requests regarding transports 24h/24h. The fare between the centre of Brussels and the airport is normally around 30 E (according to your final destination) and the fare between the congress venue and the city center (Central Station, Grand Place) is around 10 E. Taxis Verts’ telephone number : + 32 (0) 2/349 49 49.
In the city by bus Different buses are available near the Place Rogier. They can lead you to the North Station and the Central Station. For further information, check the following website : www.stib.be The Brussels bus company STIB/MIVB operates a bus link between the railway station Brussels-Luxemburg and the Brussels Airport. This line operates one to three times per hour. The fare lasts about 35 minutes and cost around 3 E.
Any advise needed about our city ? A touristic information ? A nice place for a dinner or a simple drink ? … DO NOT HESITATE to contact us at the registration area, ground floor. YOU are our host in our city and we strive to make your stay enjoyable ! 105 About Brussels
1 Sheraton - Congress Venue 2 Tulip Inn Boulevard 3 President Nord 4 Colonies 5 NH Atlanta 6 Le Métropole 7 Royal Crowne Mercure 8 Crowne Plaza 9 Le Dôme 10 Le Plaza
A city map is included in your bag or is available at the touristic information desk.
106
Oral Presentations Abstracts
Monday 12/09/05
PLENARY SESSION 8h45 - 10h00
CONFORMITY & SELECTIVITY, LUNG CANCER, CRANIOPHARYNGIOMAS, SPINAL METASTASES PS1 Chairman: Marc, Levivier Room Nation
Enhanced conformality and selectivity using robotic radiosurgery PS1-1 L. Dade, Lunsford (1); Douglas, Kondziolka (1); Ajay, Niranjan (2); John C, Flickinger (1); Ann H., Maitz (3) (1) University of Pittsburgh Medical Center - Department of Neurological Surgery; (2) University of Pittsburgh Medical Center - Neurological Surgery; (3) University of Pittsburgh Medical Center - Image Guided Neurosurgery Pittsburgh, USA Robotic gamma knife radiosurgery using multiple isocenters results in superior dose conformality (the three dimensional conforming of isodose shells to the 3-D tumor geometry) and selectivity (the reduction of dose to tissues outside of the target). We reviewed the technical evolution of radiosurgery as it applies to management of acoustic neuroma. Methods and Materials Since 1987, 1,037 patients with acoustic neuromas have undergone gamma knife radiosurgery. During the most recent five years we used the robotic automated positioning system (Model C gamma knife). This technology provides submillimeter inter-shot repositioning in order to maximize dose conformality. The usage of small beam diameters (4 mm. and 8 mm.) provided high conformali- ty and significantly reduced the integral dose to surrounding structures (high selectivity) such as the brainstem, cochlea, and trigeminal nerve. Conformal stereotactic radiosurgery is associated with hearing preservation rates between 75 and 90% with a less than 1% risk of facial weak- ness. Discussion Robotic positioning with small isocenters significantly improved our ability to contour the effective dose to the irregular three-dimensional geometry of the tumor (high confor- mality). The usage of multiple small isocenters reduced integral dose to tissue outside of the tar- get volume (enhanced selectivity). Robotic stereotactic gamma knife radiosurgery (single proce- dure) is the preferred modality. When conformality is high but selectivity is poor, stereotactic hypofractionated radiation should be considered. When conformality and selectivity are both low, conventional fractionated radiation therapy, possibly enhanced by image guidance techniques, should be considered. Stereotactic radiosurgery using the gamma knife coupled with robotic inter- shot repositioning enhanced outcomes and facilitated dose delivery in a single procedure.
107 Oral Presentations Abstracts
Stereotactic radiotherapy for patients with inoperable early stage lung cancer. A retrospective study PS1-2 Pia, Baumann (1); Lars, Ekberg (2); Ulf, Isaksson (3); Karl-Axel, Johansson (4); Ingmar, Lax (1); Rolf, Lewensohn (1); Jan, Nyman (4); Suzanne, Rehn-Eriksson (5); Lena, Wittgren (2); Signe, Friesland (1) (1) Karolinska Institutet - Department of Oncology; (2) Malmö University Hospital - Department of Oncology and Hospital Physics; (3) Karolinska Institutet - Department of Neurosurgery; (4) Sahlgrenska University Hospital - Departments of Hospital Physics and Oncology; (5) Uppsala University Hospital - Departments of Hospital Physics and Oncology Stockholm, Sweden Background: Stereotactic radiotherapy (SRT) has in our clinics been used as an alternativ treat- ment for inoperable early stage lungcancer since the beginning of 1990. Materials and methods: Ninetyfive patients with inoperable NSCLC stage I (T1 53% and T2 47%) were treated with SRT during 1996-2003 in 4 different centres in Sweden. The cancer was cytologically verified in 68 % (65/95) of cases, 35% squamous cell carcinoma, 37% adenocarcinoma and 27% other. The patients were considered inoperable mainly because of insufficient lung function and/or cardio- vascular disease. Five patients refused surgery. The mean age was 73 years (range 56-89 y). Forty six were men and 49 women. SRT was delivered after immobilizing the patients in a stereotactic body frame (SBF). 3D conformal multifield technique was used. The patients were treated with doses from 30-45 Gy (at 65%) in 2-5 fractions. The mean gross tumour volume was 36 mm3 (3- 436), the planning target volume was 98 mm3 (13-719). Results: Medium follow up time was 29 months (4-89 m). The overall response rate (CR, PR, SD) was 93 % (88/95). Local tumour pro- gression was seen in 3 patients (0.03%). Four patients were not evaluable or lost for follow up. Distant metastases occured in 21 % (20/95) of the patients. Thirty one patients (57%) died of other causes than lung cancer. The 5-year overall survival was 33 %. Toxicity was mild and 54 % (50/92) of patients had no side effects. Conclusion: Radiotherapy given with ereotactic technique, represents a promising effectiv treatment option with high local control rates and very low toxic- ity for patients with inoperable early stage lung cancer. A Nordic multicenter prospective study using SRT in NSCLC stage I will be finished this year for further evaluation of hypofractionated high dose radiotherapy.
Quality of life after stereotactic radiotherapy for stage I non-small cell lung cancer (NSCLC) PS1-3 Frank J., Lagerwaard (1); Ylanga G., van der Geld (1); Ben J., Slotman (1); Suresh, Senan (1) (1) VU Medical Center Amsterdam - Department of Radiation Oncology Amsterdam, The Netherlands Background: Although surgery is the treatment of choice for early-stage lung tumors, the risks of complications and related mortality are substantial, particularly in older patients with poor pul- monary function and/or significant co-morbidity. It has been reported that the quality of life (QoL) is adversely affected in such patients [Sarna 04]. Stereotactic radiotherapy (SRT) is a valuable alternative to surgery for medically inoperable stage I NSCLC patients, and local control rates are in excess of 80% with low toxicity. This analysis describes the early toxicity and QoL in stage I NSCLC patients following SRT. Methods: Since 2003, 84 medically inoperable stage I NSCLC patients have been treated with SRT at our center. Data on QoL have been collected prospective- ly. Patients were asked to fill out EORTC-developed QLQ-C30 3.0 and QLQ-LC13 questionnaires 108 Oral Presentations Abstracts
prior to and at preset intervals after SRT. This analysis includes patients with at least 3 months follow up. Results: The QoL data of 61 patients were included. Data were available at baseline, 3 months, 6 months and 1 year follow up in 61, 46, 38 and 13 patients, respectively. The mean pre-treatment global health status score of this patient group was 63.8 ± 20.9, which was not significantly different from measurements at 3 months (66.1 ± 18.4), 6 months (64.9 ± 15.7) or 1 year (67.3 ± 14.6). The same applied for the functional (physical, emotional, social, cogni- tive and role behavior) and symptom scales. Thirty-two patients reported early toxicity including chest wall pain, dyspnea, nausea, radiation dermatitis, fatigue and coughing. In all but one cases side effects were mild to moderate, RTOG grade 1-2. One patient required hospitalization because of grade 3 radiation-induced pneumonitis. Conclusions: No significant change in Quality of Life following SRT was detected using QLQ-C30 and QLQ-LC13 questionnaires. The reported side effects did not influence QoL.
Role of radiosurgery in the multimodality management of craniopharyngiomas PS1-4 Ajay, Niranjan (1); Pramod Kumar, Pillai (2); L. Dade, Lunsford (3); Douglas, Kondziolka (3); John C, Flickinger (3) (1) University of Pittsburgh Medical Center - Neurological Surgery; (2) University of Pittsburgh Medical Center - Neurological Surgery; (3) University of Pittsburgh Medical Center - Department of Neurological Surgery Pittsburgh, USA OBJECTIVE: To evaluate the role of radiosurgery in the multimodality management of residual of recurrent craniopharyngiomas. METHODS: Twenty-nine patients (15 males and 14 females), with a median age of 19 years (range, 5 to 82) had gamma knife radiosurgery for recurrent or resid- ual craniopharyngioma during a seventeen-year interval. In addition to surgical resection, five patients received brachytherapy and three had fractionated radiation therapy prior to radio- surgery. The median interval between diagnosis and radiosurgery was 46.5 months. The medi- an tumor volume was 0.4 (range, 0.12- 6.36) cm3. One to nine isocenters of different beam diameters were used. The median dose to the tumor margin was 12.5 Gy (range, 9-20), and the maximum dose was 25 Gy (range, 21.8-40). The dose to the optic apparatus was limited to less than 8 Gy. RESULTS: Clinical and imaging follow-up data were obtained at a median of 24 months (range, 13 to 150) from radiosurgery. Overall, 14 of 29 tumors regressed or vanished, and 10 remained stable after radiosurgery. Further tumor growth was noted in five patients, of which 3 underwent surgical resection and one had repeat radiosurgery. Two additional patients needed management for cyst enlargement. One patient with prior visual defect had further vision deteri- oration 9 months after radiosurgery. No patient developed new-onset diabetes insipidus. CON- CLUSIONS: Multimodal management is often necessary for patients with solid and cystic cranio- pharyngiomas. Stereotactic radiosurgery is a valuable minimally invasive option for patients with small recurrent or residual craniopharyngiomas.
109 Oral Presentations Abstracts
Image-Guided radiosurgery of single spinal metastasis PS1-5 Samuel, Ryu (1); Jack, Rock (2); Jian-Yue, Jin (3); Marilyn, Gates (2); Benjamin, Movsas (4); Jae Ho, Kim (5) (1) Henry Ford Hospital - Radiation Oncology; (2) Henry Ford Hospital - Neurosurgery; (3) Henry Ford Hospital - Radiation Oncology; (4) Henry Ford Hospital - Radiation Oncology; (5) Henry Ford Hospital - Division of Radiation Oncology Detroit, USA Purpose: Precision and accuracy of image-guided spinal radiosurgery has been previously demon- strated. We used spinal radiosurgery to treat a single spinal metastasis. This study was carried out to determine the clinical efficacy of spinal radiosurgery for the treatment of spinal metastases with or without cord compression. Method: A total of 49 patients with 61 lesions of separate spinal metastases were treated with radiosurgery. All patients had pathologically-proven primary cancers and had either synchronous or metachronous metastasis to the spine. The majority of the patients presented with back pain. All patients received single dose radiosurgery to the involved spine only. The radiosurgery dose ranged 10-16 Gy. The dose was prescribed to the 90% isodose line that encompassed the target volume. Followup included patient questionnaires, neurological exam, and radiological studies. The primary endpoint was pain control, but outcomes in neuro- logical status and radiological tumor control were also assessed. Results: Precision of spine radio- surgery has been determined within 1.5 mm. The median time to pain relief was 14 days and the earliest time of pain relief was within 24 hours. Complete pain relief was achieved in 46%, partial relief in 18.9%, and stable in 16.2%. Neurological improvement of motor and sensory function was achieved with a median time for improvement 14 days. Radiological tumor control was seen in patients with epidural mass or soft tissue tumor component. The dose to the spinal cord was tolerable at 10 Gy to the anterior 10% of the spinal cord. There was no detectable acute or subacute radiation toxicity noted clinically during the followup time of longer than 36 months. Conclusion: Single dose radiosurgery achieves a rapid and durable pain relief and neurological improvement in patients with spinal metastasis with or without cord compression. The results indicate the clinical effectiveness of spinal radiosurgery for malignant tumors of the spine or cord.
ORAL SESSIONS 11h30 - 12h30
LARGE ARTERIOVENOUS MALFORMATIONS OS1 Chairmen: Andras, Kemeny; Jason, Sheehan Room Nation Staged gamma knife radiosurgery, with neither surgery nor embolization, for relatively large AVMs OS1-1 Masaaki, Yamamoto (1); Bierta, E. Barfod (1); Yoichi, Urakawa (1) (1) Katsuta Hospital - Mita Gamma House Hitaxhi-Naka, Japan Introduction: Little information is available on staged gamma knife (GK) radiosurgery with an interval of more than 3 years, with neither surgery nor embolization, for relatively large AVMs. Patients and Methods: Among 240 AVM patients treated using a GK by one of the authors (MY) during a 15 yr period (1998-2003), the courses of 24 (10 females, 14 males, mean age; 31 yr, range; 9-67yr), were studied. Mean nidus volume was 13.8 cc, range 3.1 to 33.3 cc. The most common presentation was bleeding (12 patients), followed by seizure (7), incidental (3) and oth- 110 Oral Presentations Abstracts
ers (2). Before GK radiosurgery, although embolization was performed in three patients and sur- gery in one, no significant volume reductions were achieved. In all 24 patients, relatively low doses (12-16 Gy at the lesion periphery) were intentionally employied for the first GK treatment. The second GK procedure was scheduled for at least 3 yrs later. Results: To date, 14 of the 22 patients have undergone the second procedure. Six of the 14 underwent DSA 3 yrs or more after the second GK treatment. Complete nidus obliteration was confirmed in five and nearly complete obliteration in one. Six patients (25.0%) experienced bleeding after the first GK treatment; thee mortalities, two morbidities. One (4.2%) patient had treatment-related complications 24 months after the second GK procedure. Conclusions: Although our final conclusion awaits further studies and patient follow-up, these results suggest GK radiosurgery to have certain benefits even for rel- atively large AVMs.
Validation of a radiosurgery-based grading system for arteriovenous malformations OS1-2 Michael, Girvigian (1); John, Lee (1); Michael, Miller (1); Javad, Rahimian (1); Joseph, Chen (1); Hugh, Greathouse (1); Michael, Tome (1) (1) Kaiser Permanente Medical Center - Department of Radiation Oncology Los Angeles, USA Purpose: The Spetzler-Martin grading system accurately predicts outcome after surgical resection of arteriovenous malformations (AVM); however, its application to radiosurgery is limited because of insensitivity to AVM volume and location. Recently, a radiosurgical grading system was devel- oped by the Mayo Clinic/University of Pittsburgh_ to predict outcomes for Gamma Knife® radio- surgery. This retrospective study seeks to independently validate the radiosurgery grading system and determine its application to linear accelerator-based radiosurgery. Methods and Materials: 20 patients were treated with Radionics XKnife™ LINAC-based radiosurgery for AVMs between 1990-2002 (median follow-up, 35 months). Outcomes based on obliteration rates and post-treat- ment neurological deficits were analyzed according to radiosurgical grade and Spetzler-Martin grade. The following equation describes the radiosurgery grading system: AVM score = (0.1)(AVM volume in cm2) + (0.02)(age in years) + (0.3)(location) with frontal/temporal = 0; parietal/occipital/intraventricular/corpus callosum/cerebellar = 1; or basal ganglia/thalamus/ brainstem = 2. Results: Overall, 65% had excellent outcomes, 0% good, 5% fair, 25% unchanged, and 5% poor. For AVM scores 0.6 – 1.3, 9 of 9 patients (100%) had excellent out- comes. For AVM scores 1.4 – 1.7, 3/6 (50%) excellent, 1/6 (17%) fair, and 2/6 (33%) unchanged. For AVM scores 1.9 – 2.4, 1/5 (20%) excellent, 3/5 (60%) unchanged, 1/5 (20%) poor. The Spetzler-Martin grade (SMG) inconsistently predicted outcomes. For SMG 1, 4 of 4 patients (100%) had excellent outcomes. For SMG 2, 5/9 (56%) excellent, 3/9 (33%) unchanged, 1/9 (11%) poor. For SMG 3, 4/5 (80%) excellent, 1/5 (20%) fair. For SMG 4, 1/2 (50%) fair, 1/2 (50%) unchanged. Two patients (10%), with AVM scores of 1.9 and 1.6, suffered radionecrosis. No post-radiosurgery hemorrhage or AVM-related deaths occurred. Conclusions: The radiosurgery grading system accurately predicted patient outcomes, thus validating this grading system and suggesting its applicability to linear accelerator-based radiosurgery for AVMs.
111 Oral Presentations Abstracts
Radiosurgery of large cerebral arteriovenous malformations OS1-3 Dong Gyu, Kim (1); Seung-Yeob, Yang (1); Sun Ha, Paek (1); Hyun-Tai, Chung (1); Chul-Kee, Park (1); Dae Hee, Han (2) (1) Seoul National University Hospital - Department of Neurosurgery; (2) Seoul National University Hospital - Department of Neurosurgery Seoul, Republic of Korea INTRODUCTION: The authors present the retrospective analysis of clinical results of large cerebral arteriovenous malformation (AVM) treated by radiosurgery. METHODS: Between 1994 and 2004, we managed 334 patients of cerebral AVM with radiosurgery and large AVM, more than 14cc in volume, was present in 52 cases. The number of patient followed up more than 3 years was 41 among 52 cases and only these patients were included in the analysis. LINAC radiosurgery was performed until 1996 and after then gamma knife (GK) was used. Mean age was 31 years and male to female ratio was 23:18. Twenty patients had undergone endovascular treatment before radiosurgery. The whole nidus was covered and the radiosurgery was repeated three years after the first radiosurgery if there was any residual nidus. Median volume was 30cc (14~180) and mean marginal dose was 14Gy (10~27). Magnetic resonance (MR) images were obtained every six months and trans-femoral cerebral angiography (TFCA) was performed at three years after radiosurgery. RESULTS: Follow-up TFCA was performed in 19 patients and complete obliteration was observed in seven patients (37%). Remaining 12 patients who had residual nidus received second radiosurgery. Three patients were followed up more than 3 years after second radio- surgery and complete obliteration was confirmed by TFCA in two patients and the nidus was not observed on MRI in remaining one. The mean volume of nidus in second radiosurgery was 7.2cc, and it was significantly different from initial volume (p=0.02). The patients with followed up only by MRI were 22 and the rate of volume reduction measured in MRI was 56%. Hemorrhage after radiosurgery was occurred in 4 patients and three patients received craniotomy. Delayed cystic cerebromalacia formation was found in two cases and asymptomatic high signal intensity on T2- weighted MR images in 5 cases. Embolization did not have an effect on obliteration. CONCLU- SION: Staged radiosurgery might be an alternative treatment option for inoperable large AVM, however, accumulation of cases and long term follow-up are mandatory.
Staged volume radiosurgery for large arteriovenous malformations: indications and outcomes OS1-4 Douglas, Kondziolka (1); Sait, Sirin (1); John C, Flickinger (1); Niranjan, Ajay (1) (1) University of Pittsburgh Medical Center - Department of Neurological Surgery Pittsburgh, USA The obliteration response of an arteriovenous malformation (AVM) to radiosurgery is strongly dependent upon dose and volume. For larger volumes, the dose must be reduced to maintain safety, but this compromises obliteration. In 1992, we began to stage anatomic components of the nidus in order to deliver higher single doses. Numerous centers have begun to use this tech- nique, but little is known regarding results. During a 17-year interval at the University of Pittsburgh, 1040 patients underwent radiosurgery for a brain AVM. Out of 135 patients who had multiple procedures, 39 patients underwent prospectively staged volume radiosurgery for symp- tomatic larger malformations. The median age was 34 years (range, 12-57 years). Twelve patients had prior hemorrhages and 17 patients had attempted embolization. Separate anatomic volumes 112 Oral Presentations Abstracts
were treated at 3-8 month (median 5 months) intervals in patients with AVMs larger than 15 ml. All patients except one (3 stages) had 2-stage radiosurgery. The median target volume was 12 ml. (range 4.3-26 ml.) at Stage I and 11 ml. (range, 4.1-29.5) at Stage II. The median margin dose was 16 Gy at both stages. The median duration of follow-up review after the last stage of radiosurgery was 26 months (range 3-92 months). In five patients (14.2%) a hemorrhage occurred after radiosurgery. Two patients died and three patients recovered with mild permanent neurologic deficits. New or increased neurologic deficits were seen in 7 patients. Seizure control was improved in three patients, stable in 20 patients and worse in two patients. Imaging showed peri-AVM edema in four patients (11%). Out of 17 patients followed for more than 36 months, 7 had total (41%) and 7 near total (41%) AVM obliteration. Prospective staged volume radio- surgery for large AVMs with results that appear better than single stage radiosurgery at lower doses. Further evaluation of this method is required.
RADIOBIOLOGY OS2 Chairmen: John, Flickinger; Ronald, Mc Garry Room Permeke & Rembrandt
Stereotactic pulmonary hilar radiation: an animal model of radiotoxicity OS2-1 Brent, Tinnel (1); Marc, Mendonca (2); Ronald, McGarry (3); Oscar, Cummings (4); Robert, Timmerman (5) (1) Indiana University Medical Center - Department of Radiation Oncology; (2) Indiana University Medical Center - Radiation and Cancer Biology; (3) Indiana University Medical Center - Department of Radiation Oncology; (4) Indiana University School of Medicine - Department of Pathology; (5) University of Texas Southwestern - Department of Radiation Oncology Indianapolis, USA Purpose/Objective: Stereotactic body radiation therapy uses high doses/few fractions of radiation to ablate lung cancers; however concerns have been raised about toxicity on normal large airways. We have developed a model of high dose, hypofractionated radiotherapy to the pulmonary hilum. Materials/Methods: Thirty-four Sprague-Dawley rats were subjected to focal irradiation of the uni- lateral lung hilum. CT simulation at 1 mm thickness was used to acquire target information. Cohort of three animals received single fractions of Gamma-Knife radiotherapy centered on the right main bronchus. The initial cohort received 10 Gy prescribed to the 50% isodose line, using two 4 mm collimated 'shots', differing by 1 mm in the Z axis only. Escalating doses of 20, 40 and 80 Gy in single fractions were performed. A second cohort was treated in the same fashion using an 8.0mm collimator. Results: Animals were observed for toxicity until sacrifice. No changes were seen on plain films or follow-up CT scans. On histopathologic analysis, only animals irradiated with 8-mm collimator and sacrificed at 6 months demonstrated any changes (7/34). Cellular atypia and inter- stitial pneumonitis were the most common findings. However, 3/7 showed clear bronchial dam- age and 2/7 showed vascular damage. One animal had atelectasis related to marked bronchial damage and vascular occlusion. Statistical analysis (Fisher's Exact Test) supports a volume effect (47% of the 8-mm Vs 0% of the 4-mm demonstrated changes, p=0.0001). The time interval from irradiation to any observed changes was also significant (0% in the 3-4 month groups had changes Vs 39% of the 6 month groups p=0.01). Conclusions: Small volume/high dose radiotherapy cen- tered on the bronchus is well tolerated in rats. However, our observation of severe histopatholo- 113 Oral Presentations Abstracts
gical changes suggests a dose/volume relationship with damage to the surrounding stroma may be important in the etiology of bronchial or hilar damage.
Histopathologic changes in metastatic brain tumors seen after gamma knife radiosurgery: the Pittsburgh experience OS2-2 Dave, Atteberry (1); Gyorgy, Szeifert (2); Marta, Couce (3); Douglas, Kondziolka (1); L. Dade, Lunsford (1) (1) University of Pittsburgh Medical Center - Department of Neurological Surgery; (2) National Institute of Neurosurgery - Department of Neurosurgery; (3) University of Pittsburgh Medical Center - Pathology Pittsburgh, USA Background: Radiosurgery for metastatic brain tumors is widely performed. Because of the effi- cacy of this treatment, craniotomy for resection of these lesions is rarely required. Therefore, little is known about the histologic changes that these tumors undergo after such treatment. This study aims to characterize the histopathologic changes in metastatic brain tumors after treatment with gamma knife radiosurgery. Methods: All patients with metastatic brain tumors who were treated at the University of Pittsburgh between June 1987 and July 2004 who underwent subsequent craniotomy for tumor resection were studied. Demographic variables such as age, gender, and radiosurgery-craniotomy time interval (RS-CR), type of tumor, and gamma knife treatment param- eters such as volume of tumor and isodose were collected. Routine histological and immunohis- tochemical investigations were carried out on the fixed surgical specimens. The pathologic spec- imens were categorized according to type of changes seen: acute-type (necrotic activity), suba- cute-type (resorptive activity), and chronic (reparative activity). Descriptive statistics were used to describe the findings of this case series. Results: The University of Pittsburgh radiosurgery series was 6, 500 patients by July 2004. Surgical pathology material was available in 11 patients (15 procedures), 4-59 months after radiosurgery (mean 15 months). The age range was 41-72 (mean 53), 55% were female. The lesions studied were of the following tumor types: non-small cell (NSC) lung cancer (CA) (9), breast CA (2), renal cell CA (2), melanoma (1), and small cell lung CA (1). Tumor volume varied from 268-23,600 mm3. Isodose prescriptions varied from 14 Gy/ 50% to 20 Gy/50%. Two lesions were classified as acute-type (1 NSC lung CA, 1 small cell lung CA), 11 were classified as subacute-type (8 NSC lung CA, 2 renal cell CA, and 1 melanoma), and 1 was classified as chronic (breast CA). The other breast CA lesion was classified as a mixture of acute and subacute types. The three histopathologic phenotypes were largely recognized in dif- ferent tumors irrespective of their ontogenetic nature. There was no significant relationship between morphologic characteristics and the RS-CR. Conclusions: This case series describes the histopathologic changes seen in metastatic brain tumors after gamma knife radiosurgery. The information gleaned from this study may help to elucidate the pathophysiologic mechanisms by which radiosurgery destroys tumor cells. The relative time and environment independence of the post-radiosurgery lesions may suggest either a vascular mechanism or a genetic origin that is pre- sumably induced by the ionizing energy of high dose irradiation.
114 Oral Presentations Abstracts
Early and late adverse effects of low-dose radiosurgery in MR area OS2-3 Hiroshi K., Inoue (1) (1) Institute of Neural Organization - Restorative Neurosurgery Fujioka, Japan Cranial nerve damages, cerebral edema, necrosis, arterial stenosis, intratumoral hemorrhage, cyst formation, radiation induced tumors, etc. are reported as the complications of radiosurgery. Those complications seem to be decreased in low-dose treatment because good functional preservation has been obtained in vestibular schwannomas treated with low-dose. It reviewed from the case followed more than 10 years after treatment. The object is example of 227 of AVMs (92), schwan- nomas (67), meningiomas (41), pituitary adenomas and so on which was treated mostly with low-dose by April, 1995. Cranial nerve symptoms which were directly related with lesions were excluded. Symptomatic early complications were extensive brain edema in two patients and hydrocephalus in two appeared 6 months after treatment. Delayed cyst formation was found in one patient as late complication 10 years after treatment. Asymptomatic complications were found as brain necrosis, stenosis of the internal carotid artery and intratumoral hemorrhage. Multiple tumors appeared in one patient 7 years after treatment. However, no complication-relat- ed death was recognized to date. High dose exposure including central dose may cause long- term effects to the brain parenchyma, artery and pathologies. Sensitivity of DNA damage and tumor genesis may be not related with dose amount of treatment.
Alpha/beta ratios for radiosurgical target tissues OS2-4 Frederik, Vernimmen (1); Jacobus, Slabbert (2) (1) Stellenbosch University - Radiation Oncology; (2) iThemba LABS - Radiation Biophysics Tygerberg, South Africa Objectives Arteriovenous malformations, skull base meningiomas, and acoustic neuromas can be successfully treated with one fraction of radiation (radiosurgery) when conventional surgery is not possible or desired. Extensive clinical experience with radiosurgery has been accumulated for these lesions and interest in giving the total radiation dose in a limited number of fractions (hypo- fractionated stereotactic radiotherapy) in certain cases is growing. The dose/fractionation sched- ules used in these treatments are based mainly on general clinical assumptions. In order to cor- rectly determine the optimum dose/fractionation schedule, the repair characteristics as quantified by the alpha/beta ratio of the specific radiation effect on the tissue in question has to be known. Design and methods Using clinical data from the proton therapy program at iThemba LABS as well as data from the literature, FE plots were constructed for specific end results. These relate dose per fraction given to the iso-effective dose for different treatment protocols. Data for skull base meningiomas and acoustic neuromas were analyzed for patients that achievement long term radiological control. Arteriovenous malformations were studied in patients obtaining obliteration. All three pathologies when treated at iThemba LABS received between 1 and 3 fractions, with the majority of patients treated in 3 fractions. These data formed the basis for this study. In addi- tion, data from the literature dealing with these same pathologies in terms of observed effect and size of lesions were also included in the analysis to help estimate repair constants. Results For long-term radiological control of skull base meningiomas an alpha/beta value of 3.7 Gy was determined. Long-term radiological control in acoustic neuromas is reflected in an alpha/beta 115 Oral Presentations Abstracts
value of 1.4 Gy. A higher then expected alpha/beta value of 9.4 Gy was found for the oblitera- tion of predominantly large cerebral AVMs. Conclusion The repair characteristics of AVMs appear to be considerable less from what is generally assumed based on clinical observations of this clas- sical radiosurgical target tissue. By contrast, alpha/beta ratios for meningiomas and schwanomas are more typical for lesions best treated in a hypo-fractionated manner. The values found in this study are most useful for use in calculating the optimum dose/fractionation schedule as well as to help indicate if hypo- fractionation is indeed likely to translate in therapeutic gain for such radiosurgical targets.
GLIOMAS OS3 Chairmen: Minesh, Mehta; Nicolas, Massager Room Willumsen
PET-related metabolic response of glial tumors after GK radiosurgery OS3-1 Nicolas, Massager (1); Bich-Ngoc-Thanh, Tang (2); Daniel, Devriendt (3); Ouzi, Nissim (4); David, Wikler (2); Françoise, Desmedt (4); Jacques, Brotchi (1); Serge, Goldman (2); Marc, Levivier (4) (1) Hôpital Erasme - Neurochirurgie; (2) Hôpital Erasme - PET Scan; (3) Institut J. Bordet - Radiothérapie; (4) Hôpital Erasme - Centre Gamme Knife Brussels, Belgium Objective: To evaluate the metabolic response of cerebral gliomas after gamma knife radiosurgery (GKR). Material & Methods: Between December 1999 and December 2004, 55 patients were treated by GKR in our center for a cerebral glioma using a combination of MR and PET guidance. One or multiple PET-scan were performed in the clinical follow-up for 38 patients, including 16 patients with a low-grade glioma (LGG) and 22 patients with a high-grade glioma (HGG). The PET radiotracer was FDG for 13 patients (including 10 patients with HGG) and methionine for 25 patients (including 13 patients with LGG). We analyzed the relation between modifications in the uptake of PET radiotracer after radiosurgery, histology and the volumetric and dosimetric param- eters of the GKR procedure. Results: One to 10 serial PET-scan was acquired during the follow-up of those patients, ranging from 3 months to 5 years (mean: 14 months). The PET-related metabol- ic activity of the tumor reduced significantly for 21 patients (55%), remained stable for 6 patients (16%) and increased for 11 patients (29%). Significant changes of tumor metabolism after GKR were more frequent with the use of methionine than FDG (64 vs 38%, respectively). For some patients, we have registered an initial reduction of tumor metabolism after radiosurgery, followed by an increase in metabolism. No statistically significant relation was found between histology, volumetric and dosimetric parameters of the radiosurgical procedure and the metabolic response of the tumor. For all patients, failure of tumor control occured by an increase in glioma metabo- lism assessed by PET prior to apparition of signs of tumor growth on MRI. Conclusion: PET-scan can help in the follow-up of patients with LGG and HGG after GKR. The metabolic response seems not to be related to any volumetric or dosimetric parameters of the GKR procedure.
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Rationale for, and results of a 6-year experience of “Leading Edge” gamma knife radiosurgery for glioblastoma multiforme: a trend toward improved outcome OS3-2 Christopher M., Duma (1); W. Michael, Shea (2); Jay, Tassin (2); Peter, Chen (2); Ralph, Mackintosh (2); Marianne, Plunkett (2) (1) Hoag Memorial Hospital - Department of Neurosurgery; (2) Hoag Memorial Hospital - Radiation Oncology Newport Beach, USA Glioblastoma multiforme (GBM) fails current therapies due to poor local control. The tumor is radi- ation sensitive, yet failure within the treatment area of involved field radiation therapy is usually the rule. We contend that GBM is a “local disease” that has spread in a predictable pattern down white matter tracts. For the past 6 years, we have targeted known tumor migration pathways using high-dose single-fraction radiosurgery distant from the enhancing margin of the tumor using MR-SPECT and MR FLAIR sequences for direction. Sixty-eight consecutive patients with newly diagnosed GBM were treated using up-front leading edge gamma knife radiosurgery (LEGKR). Ages ranged from 20 to 83 years (median: 58). The high-signal regions on MR FLAIR sequences and/or MR Spect-positive zones outside of the gadolinium-enhancing portion of the tumor were targeted. Forty percent had received IFXRT and 45% had received chemotherapy prior to their treatment. Nine patients had 2 LEGKRS treatments. An additional 23 patients with recur- rent disease were treated in the same fashion. Median age was 56 (24-78). Four patients had 2 LEGKR treatments. Ninety-five percent had IFXRT and 45% had chemotherapy pre-LEGKR. Median leading edge volume for the two groups was 26.5 cm3 (median diameter 3.7 cm.). Median dose was 11 Gy at the 50% isodose line. Follow-up for the up-front treated group ranged from 4 to 64 months after diagnosis (median: 8 months) and from 1 to 60 months (median: 10 months) after radiosurgery. The median projected survival using the technique of Kaplan and Meier for patients undergoing LEGKR as part of their initial treatment was 82.2 weeks. Median projected survival of patients treated for recurrent disease was 86 weeks from diagnosis and 26 weeks from LEGKR. Seven patients required hospitalization for intravenous mannitol and dexam- ethasone; 4 patients in the up-front group and none from the recurrent group required surgical debulking for mass effect. Eight patients (9%) are alive more than 3 years from diagnosis. The concept of radiosurgical treatment of the “leading edge” of these tumors is a novel one that has not been formally tested in earlier clinical studies. Based on these data further evaluation of this technique is clearly warranted, perhaps with a multi-institution study. We contend that radio- surgery does have a place in the treatment of GBM.
Quantification of surrogate tracers for glioma radiosensitization OS3-3 Peter, Haar (1); William, Broaddus (1); Zhijian, Chen (1); Panos, Fatouros (2) (1) Medical College of Virginia - Division of Neurosurgery; (2) Medical College of Virginia - Radiation Physics and Biology Richmond, USA PURPOSE: Glioma radiosensitization, in which an agent such as HSV-TK is delivered intratumoral- ly via direct positive-pressure infusion, has recently shown significant therapeutic potential. However, in order for radiosensitization to be used effectively with stereotactic radiosurgery, spa- tial concentration distributions of a delivered therapeutic agent must be accurately quantified throughout the brain. For these reasons, methods were explored to non-invasively quantify three- 117 Oral Presentations Abstracts
dimensional profiles of a gadolinium-based surrogate tracer in the setting of brain infusion. MATERIALS AND METHODS: Two studies were performed: first, an MRI method was calibrated to quantify a surrogate tracer in brain parenchyma; second, this method was used to observe, over time, brain distributions of a surrogate tracer following brain infusion. In the first study, solu- tions of three different concentrations of Gd-DTPA were infused over 50 minutes to the right cau- date-putamen of 15 rats. Changes in T1 relaxation rates, measured with magnetic resonance imaging (MRI), were compared to 1mm brain slice concentrations determined with inductively coupled plasma atomic emission spectroscopy (ICP-AES) to calculate the specific relaxivity of Gd- DTPA in brain. Additionally, samples of cerebrospinal fluid (CSF), blood and urine were analyzed to evaluate Gd-DTPA clearance from the brain. In the second study, a Gd-DTPA solution was infused over 50 minutes to the caudate-putamen in five rats, then allowed to diffuse for 80 min- utes. In each rat, computed T1 map data sets were acquired at thirteen time points throughout the duration of the experiment, and were used to calculate three-dimensional Gd-DTPA concen- tration distributions at each time point. The experimental results were evaluated statistically in terms of volume of distribution of tracer, total content of tracer in the brain, and average tissue concentrations of tracer. RESULTS: The relaxivity of the tracer Gd-DTPA following brain infusion was measured to be 5.34 (mM*s)^-1 in a 2.4 T field, a value considerably higher than previous estimates. Measurements of brain Gd-DTPA tissue concentrations using MRI and ICP-AES demon- strated a high degree of coincidence, indicating the accuracy of this quantification approach. Clearance of Gd-DTPA in the CSF, blood and urine was measured to be minimal at the time point immediately after infusion. The measured average volume of distribution increased linearly with a regression slope of 0.673 mm^3/minute during the infusion period, after which it leveled, with a slope not statistically different from 0 (p < 0.01). The average measured brain content of tracer similarly increased linearly during the infusion with a slope of 0.172 nanomoles/minute, reflecting the constant infusion flow rate. Following the end of infusion, the average tissue con- centrations of tracer declined at a rate of -0.0012 nanomoles/mm^3/minute, suggesting diffu- sive transport. CONCLUSIONS: These results demonstrate that MRI T1 mapping can be used effec- tively to measure surrogate tracer concentrations, allowing accurate, non-invasive visualization of infused medications. This surrogate tracer approach will allow radiosurgical doses to be precise- ly adjusted on the basis of known local drug concentrations and expected radiosensitivities.
Role of gamma knife radiosurgery in malignant glioma treatment OS3-4 Masaaki, Yamamoto (1); Bierta E. Barfod (1); Yoichi, Urakawa (1) (1) Katsuta Hospital - Mita Gamma House Hitaxhi-Naka, Japan Introduction: The clinical efficacy of gamma knife (GK) radiosurgery for managing patients with malignant gliomas is not yet fully understood. Treatment results for our series of patients who underwent GK radiosurgery are described. Patients: Among our consecutive series of 2426 patients who underwent GK radiosurgery from July, 1998 through June 2004, 84 whose tumors were histologically verified as malignant gliomas were selected for this study. The mean patient age was 57 years, range from 24 to 83 years. There were 32 females and 52 males. Histological diagnosis was grade III (gr-III) in 36 patients, grade IV (gr-IV) in the other 48. Results: When the medical records of the 84 patients were reviewed in mid-March of 2005, nine patients were alive 118 Oral Presentations Abstracts
and the other 75 were confirmed to be deceased. Causes of death were brain tumor progression in 69 and unrelated diseases in three. The remaining three had been found in a state of cardiopul- monary arrest, and could not be resuscitated. Median survival times (MSTs-months) from the time of GK until death caused by tumor progression were 12 in gr-III and 10 in gr-IV patients (p=. 0123). GK radiosurgery was performed as one of the initial treatment procedures in 28 patients. In this group, MSTs were 13 for gr-III and 12 for gr-IV (p=.6009). Although MSTs did not differ between two treatment strategies, GK only versus radiotherapy (RT) plus a GK booster, there was a significant MST difference between these treatments in a special group of patients who under- went more than 95% tumor removal; 30 for GK only and 16 for RT plus GK (p=.0165). Furthermore, if sufficiently high doses were given using GK only, the MST of 15 was essentially the same as that in patients undergoing RT plus GK (p=.3558). In contrast, in the other 56 of our 84 patients, GK radiosurgery was performed for recurrent tumors. In this group, MSTs were 11 for gr-III and 8 for gr-IV patients (p=.0061). Conclusion: GK radiosurgery may replace RT in the initial management of selected patients with malignant gliomas. GK radiosurgery is applica- ble to recurrent malignant gliomas.
ORAL SESSIONS 14h00 - 15h00
VESTIBULAR SCHWANNOMAS 1 OS4 Chairmen: L. Dade, Lunsford; Roberto, Spiegelmann Room Nation
Estimating tumor definition variability in acoustic schwannoma radiosurgery, and how it affects dosimetry OS4-1 John, Flickinger (1); Ajay, Niranjan (2); Kaan, Oysul (1); Juan, Martin (3); Sait, Sirin (4); Ann H., Maitz (5); Douglas, Kondziolka (5); L. Dade, Lunsford (5) (1) University of Pittsburgh Medical Center - Department of Radiation Oncology; (2) University of Pittsburgh Medical Center - Neurological Surgery; (3) Department of Neurological Surgery - University of Pittsburgh; (4) University of Pittsburgh Medical Center - Department of Neurological Surgery; (5) University of Pittsburgh Medical Center - Image Guided Neurosurgery Pittsburgh, USA Objective: Different physicians vary in what they define as tumor volumes for radiosurgery. We sought to define this variability in acoustic schwannomas and to assess how it affects assess- ments of treatment coverage by radiosurgery plans. Methods: Gross tumor volumes (GTV) were drawn after completion of gamma knife radiosurgery to ten unilateral acoustic schwannomas. Four physicians drew each contour three separate times. Prescription doses varied from 12-13 Gy (12.5 Gy in 7/10) to the 50-60 % isodose (median 50%) using 3-9 isocenters (median 6). To cre- ate uniformity in assessing the dosimetry for this study we normalized prescription doses to 12.5 Gy for the 3 cases prescribed to 12 or 13 Gy. Results: The mean GTV varied from 0.097-1.275 mL (median 0.271 mL). The mean per cent difference between individual GTV’s and the mean GTV for each tumor was 7.4 +/-5.9 % (range 0.13-28.9%), dropping to 2.1 +/-1.5 % for the average from one contour each from 3 different physicians. Mean tumor coverage by the prescrip- tion dose varied from 87.7-97.6 % (mean 94.3 +/-3.8 %). The mean difference between the individual tumor coverage percentages and the mean for each tumor was 1.5 +/-1.5 % (range 0-10.5 %), dropping to 0.7 +/-0.34 % for averaging one contour each from 3 physicians. Mean 119 Oral Presentations Abstracts
dose covering 99 % of the tumor (Dose@99%) varied from 8.2-12.5 Gy (median 10.9). The mean difference between the individual Doses@99% and the mean for each tumor was 0.43 +/-0.38 Gy (range 0-1.82 Gy), dropping to 0.16 +/-0.13 Gy for the average from 3 physicians. The mean absolute minimum tumor dose (Dmin) varied from 7.3-9.4 Gy (mean 8.3 +/-1.4 Gy). The mean difference between the individual Dmin values and the mean for each tumor was 0.84 +/-1.02 Gy (range 0-3.54 Gy), dropping to 0.29 +/-0.23 Gy for the average from 3 physicians. Conclusion: Variability in defining a tumor volume for radiosurgery leads to different estimates of tumor volume, per cent tumor coverage, Dose@99%, and absolute minimum tumor dose.
Hearing preservation in vestibular schwannoma after gamma knife radiosurgery OS4-2 Dong Gyu, Kim (1); Seung-Yeob, Yang (1); Sun Ha, Paek (1); Hyun-Tai, Chung (1); Chul-Kee, Park (1); Hee-Won, Jung (1) (1) Seoul National University Hospital - Department of Neurosurgery Seoul, Republic of Korea Introduction: To evaluate hearing preservation rate and its prognostic factors after gamma knife radiosurgery (GKS) in vestibular schwannoma, the authors analyzed the outcomes of the hearing after the GKS. Methods: Between 1998 and 2003, we managed 296 patients who were diag- nosed as vestibular schwannomas with GKS and among them, 46 patients in serviceable hear- ing with a sporadic vestibular schwannoma had been enrolled. Neurofibromatosis type 2 patients were excluded. The mean age was 48 years (21–71). Twenty eight patients were in the Gardner- Robertson (G-R) grade I and eighteen patients in G-R grade II before GKS. The median tumor vol- ume was 2.0cc (0.1-19) and mean prescription dose was 12.0 Gy (9-15) at an isodose line of 50%. Clinical assessments including neurological examination, audiometries, and neuroimaging studies were performed every six months after GKS. The median follow-up periods for audiome- try and MR images were 27 months (2-70) and 30 months (6-75), respectively. Results: Tumor control was achieved in 44 patients (96%), and tumor size was decreased in 27 patients, remained stable in 17 patients. Among the patients with tumor growth, one patient was observed without further treatment, and the other patient underwent microsurgery. New facial or trigeminal nerve dysfunction was not happened while the preexisting trigeminal nerve dysfunc- tion was aggravated in one patient. Serviceable hearing was remained in twenty seven(59%) patients and among them, fourteen (30%) patients remained in the same G-R grades as the pre- GK G-R grades. Multivariate analysis demonstrated that the G-R grade I, dose(less than 12 Gy), tumor volume(less than 4cc), and the absence of cystic portion were the factor associated with hearing preservation (p<0.05). Conclusion: GKS may be good for hearing preservation in small and solid vestibular schwannoma. The GKS is a good alternative modality for hearing preserva- tion in the patients with vestibular schwannoma.
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Hearing preservation after GK radiosurgery for vestibular schwannoma: Influence of intracanalicular dosimetric parameters OS4-3 Nicolas, Massager (1); Ouzi, Nissim (2); Carine, Delbrouck (3); Daniel, Devriendt (4); Philippe, David (5); Françoise, Desmedt (2); David, Wikler (6); Jacques, Brotchi (1); Sergio, Hassid (7); Marc, Levivier (2) (1) Hôpital Erasme - Neurochirurgie; (2) Hôpital Erasme - Centre Gamme Knife; (3) Hôpital Erasme - Centre Gamme Knife; (4) Institut J. Bordet - Radiothérapie; (5) Hôpital Erasme - Neuroradiologie; (6) Hôpital Erasme - PET Scan; (7) Hôpital Erasme - ENT Dept. Brussels, Belgium Objective: To analyze the relationship between hearing preservation after gamma knife Radiosurgery (GKR) treatment of vestibular schwannoma (VS) and the volumetric and dosimetric parameters of the intra- and extracanalicular parts of VS. Material & Methods: Between January 2000 and December 2004, 165 patients with a VS were treated by GKR in our center. Among these patients, we have selected 82 patients with the following characteristics: no NF2 disease, Gardner-Robertson hearing class 1-4 the day before the treatment, a margin dose of 12 Gy, and a radiological and audiological follow-up ¡_1 year post-GKR. On the radiosurgical planning of each patient, we measured the volume, the mean and the integrated dose delivered to both the entire tumor volume and the intracanalicular part of the tumor. We correlated those values to the auditory outcome of patients. Results: The mean hearing follow-up was 1.79y (range 1-4y); 52 patients (63.4%) had no hearing worsening on last audiological follow-up and 30 patients had an increase of ¡_1 class on the Gardner-Robertson classification. Mann-Whitney statistical test was used to analyze relation between audiological outcome and the median total tumor volume, intracanalicular tumor volume, ratio intracanalicular volume/total volume, conformity index, mean dose delivered to the total tumor volume and to the intracanalicular tumor volume, integrated dose delivered to the total tumor volume and to the intracanalicular tumor volume. Among the group of patients with hearing worsening after GKR, none had a entirely extracanalicular VS and 23.3% were entirely intracanalicular, compared to 9.6% and 17.3% respectively in the group with no hearing reduction after GKR. Conclusion: hearing preservation after GKR for VS is related to some volumetric and dosimetric parameters of the intracanalicular part of the tumor.
A prospective series of 1000 vestibular schwannomas treated by “low dose” radiosurgery: long term results OS4-4 Jean, Regis (1); Pierre-Hugues, Roche (2); Christine, Delsanti (3); William, Pellet (1) (1) CHU La Timone - Service de Neurochirurgie; (2) CHU La Timone - neurochirurgie; (3) CHU La Timone - Gamma Unit Marseille, France Background : Historical series of radiosurgery for acoustic are usually long term results for lesions treated with relatively high doses (>14Gy) at the margin. Long term results of radiosurgery with low marginal dosage remains poorly documented. Material and method : Since the 14th of july 1992, 1500 vestibular schwannomas have been treated and followed prospectively in Marseille Timone University hospital. We have analysed the results of the first 1000 patient treated with marginal doses lower than 14Gy with more than 3 years follow up (treated between july 1992 and January 2002). Results : According to the Koos topographical classification, there were pre- operatively 84 stage I, 538 stage II, 322 stage III, and 56 stage IV cases. A significant transient increase in tumor size was recorded in 15 % of the patients. Tumor control was achieved in 97% 121 Oral Presentations Abstracts
of cases. Transient facial palsy was observed in 0,7%. Among the 175 patients, with a VS and functional preoperative hearing (Gardner and Robertson 1 or 2) functional hearing preservation was achieved in 60% of the patients. Univariate and multivariate analysis have revealed param- eters which influence the probability of functional hearing preservation at 3 years. These param- eters include: a limited hearing loss (Gardner/Robertson stage 1), the presence of a tinnitus, younger age of the patient, and small lesion size. Functional hearing preservation at 3 years is 77.8% in patients with stage 1 hearing, 80% in patients with tinnitus as a first symptom, and 95% when the patient has both stage 1 hearing and tinnitus. Conclusion : Long term tumor con- trol in vestibular schwannomas treated with low dose radiosurgery appears satisfactory. This series confirm that a high rate of functional hearing preservation can be reached in selected can- didates with radiosurgery.
LUNG TUMORS 1 OS5 Chairmen: Ingmar, Lax; Paul, VanHoutte Room Permeke & Rembrandt
A prospective trial on stereotactic radiotherapy of limited stage non-small cell lung cancer OS5-1 Morten, Hoyer (1); Henrik, Roed (2); Anders, Traberg Hansen (1); Lars Peter, Ohlhues (2); Jorgen, Petersen (1); Hanne, Nellemann (3); Anne Kiil, Berthelsen (2); Cai, Grau (1); Sv. Aage, Engelholm (2); Hans, von der Maase (1) (1) Aarhus University Hospital - Department of Oncology; (2) Copenhagen University Hospital - Department of Oncology; (3) Aarhus University Hospital - Department of Diagnostic Radiology Aarhus C, Denmark Surgery is the principal treatment of patients with limited stage non-small cell lung cancer (NSCLC). However, a large proportion of patients are not suitable for thoracotomy due to severe co-morbidity. Stereotactic body radiotherapy (SBRT) have been used for treatment of patients with limited stage NSCLC who are unfit for resection. Forty patients with stage I NSCLC were included into a phase II trial. The patients were immobilized by the Elekta stereotactic body frame (SBF) or a custom made body frame. SBRT was given on standard LINAC with standard multi-leaf collima- tor. Central dose was 15 Gy x 3 within 5-8 days. Median follow-up time af the patients was 2,4 years. Eight (20%) patients obtained a complete response, 15 (38%) had a partial response and 12 (30%) had no change or could not be evaluated. Only 3 patients had a local recurrence and local control rate two years after SBRT was 85%. At two years, 54% were without local or dis- tant progression and overall survival was 47%. Within 6 months after treatment, one or more grade 2 reactions such as chest pain, skin reaction, increased used of analgesics, dyspnoea and deterioration in WHO performance status to 2 or higher was observed in 48% of the patients. Sixty-two percent and 63% of the patients experienced transient or permanent deterioration in lung function (grade>1) or performance status (WHO>1) during follow-up. SBRT in patients with limited stage NSCLC resulted in high probability of local control and promising survival rate. The toxicity after SBRT of lung tumours was moderate. However, deterioration in performance sta- tus, respiratory insufficiency and other side effects were observed.
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CT appearance of radiation injury of the lung and clinical symptoms after stereotactic radiation therapy (SRT) for lung cancers OS5-2 Tomoki, Kimura (1); Yuji, Murakami (2); Kanji, Matsuura (3); Yasutoshi, Hashimoto (4); Masahiro, Kenjo (5); Yuko, Kaneyasu (6); Koichi, Wadasaki (7); Yutaka, Hirokawa (8); Motoomi, Ohkawa (9); Katsuhide, Ito (10) (1) Kagawa University - Radiology; (2) Hiroshima University School of Medicine - Radiology; (3) Hiroshima University School of Medicine - Radiology; (4) Hiroshima University School of Medicine - Radiology; (5) Hiroshima University School of Medicine - Radiology; (6) Hiroshima University School of Medicine - Radiology; (7) Hiroshima University School of Medicine - Radiology; (8) Juntendo University - Radiology; (9) Kagawa University - Radiology; (10) Hiroshima University School of Medicine - Radiology Kagawa Prefecture, Japan (Purpose) The purpose of this study was to evaluate the CT appearance of radiation injury to the lung, clinical symptoms and the effect of pulmonary emphysema after SRT (stereotactic radiation therapy) for lung cancers. (Methods and Materials) In this analysis, 38 patients with 44 primary or metastatic lung cancers were enrolled. SRT was performed using 3D conformal method which delivers a single high dose to the tumor. We evaluated the CT appearance of acute radiation pneumonitis (within 6 months) and radiation fibrosis (after 6 months) after SRT. Clinical symptoms were evaluated by CTCAE ver.3.0. (Results) CT appearance of acute radiation pneumonitis was classified as follows ;1)diffuse consolidation in 16 lesions (36.4%), 2) patchy consolidation and ground-grass opacities (GGO) in 6 lesions (13.6%), 3) diffuse GGO in 6 patients (13.6%), 4) patchy GGO in 1 lesion (2.3%), 5) no evidence of increasing density in 15 lesions (34.1%). CT appearance of radiation fibrosis was classified as follows; 1) modified conventional pattern (con- solidation, volume loss and bronchiectasis similar to, but less extensive than conventional radia- tion fibrosis) in 23 lesions (52.7%), 2) mass-like pattern (focal consolidation limited around the tumor) in 10 lesions (22.7%), 3) scar-like pattern (linear opacity in the region of the tumor asso- ciated with volume loss) in 11 lesions (25.0%). Sixteen patients had pulmonary emphysema (42.1%) and its percentage was significantly high in patients who were classified into no evi- dence of increasing density or scar-like pattern (p=0.0002, 0.0003, respectively). (Conclusion) CT appearance after SRT was classified into five patterns of acute radiation pneumonitis and three patterns of radiation fibrosis. Most of patients who were classified into no evidence of increasing density or scar-like pattern had pulmonary emphysema and were not also diagnosed with more than grade 2 pneumonitis.
CT-guided stereotactic radiotherapy for stage I non-small cell lung cancers: 10-year experiences with the fusion of CT and Linac (FOCAL) unit OS5-3 Minoru, Uematsu (1); Akira, Shioda (2) (1) Keio University - Department of Radiology; (2) National Defense Medical College - Radiation Oncology Tokyo , Japan Stereotactic radiotherapy (SRT) is highly effective for brain metastases from non-small cell lung cancers (NSCLC). As such, primary lesions of NSCLC may also be treated well by similar SRT. Between 1994 and 2002, with the fusion of CT and Linac (FOCAL) unit, 100 patients with patho- logically proven T1-2N0M0 NSCLC were treated by CT-guided focal high-dose SRT at the National Defense Medical College in Japan. Of these 49 were medically inoperable, and remaining 51 were medically operable but refused surgery. In most patients, SRT was 50-60 Gy in 5-10 frac- 123 Oral Presentations Abstracts
tions over 1-2 weeks. Twenty-five patients also received conventional radiotherapy before SRT to reduce the tumor volume. With a median follow-up period of 62 months, the 5-year overall and cause-specific survival rate was 51% and 72%, respectively. The crude local progression free rate was 97%. There was one treatment-related death and the crude motality rate was 1%. The other adverse effects were not severe. Among 51 patients who were medically operable but refused surgery, the 5-year overall survival rate was 78% and as high as those following surgery. CT-guid- ed focal high-dose SRT was acceptably safe and effective for patients with stage I NSCLC. Since april 2004, treatment fees of this new approach was covered by the governmental health insur- ance in Japan.
Dose-response relationship in fractionated stereotactic radiotherapy (FSRT) for non small cell lung cancer (NSCLC) OS5-4 Hilde, Van Parijs (1); Jan, Van de Steene (1); Vincent, Vinh-Hung (1); Dirk, Verellen (2); Guy, Storme (1) (1) AZ VUB - Radiothérapie; (2) AZ VUB - Physique Brussels , Belgium Objective/Purpose: Our objective was to examen a possible dose-response relationship in frac- tionated stereotactic radiotherapy (FSRT) for NSCLC. Materials/Methods: Records of 25 patients from the AZ-VUB who received FSRT for NSCLC between July 2001 and May 2004 were reviewed. All patients were part of a hypofractionation study. Fractionation schemes ranged from 10 x 5 Gy to 2 x 20 Gy when curative intent, from 7 x 5 Gy to 3 x 10 when palliative. All doses mentioned are 2 Gy equivalence doses (2GyEQD), calculated with an a/b = 8. Included were 20 male and 5 female patients with NSCLC stage I (10), II (1), III (13) or IV (1). Treatment planning was per- formed with image fusion of CT and FDG-PET scan. The PET-scan integrates tumour-movement due to breathing. Treatment was delivered with X-ray image guidance (IGRT). IGRT was based on fiducial metallic markers (Fibered Platinum Coil, Boston Scientific/Target Therapeutics, Fremont, CA) implanted intra-tumouraly in 7 cases. IGRT was based on bone structures in the other 18 patients. PTV was enclosed by the 95%-isodose. The PTV-margins were 4-8 mm in case of mark- ers, 10-12 mm without marker. This population was devided into two groups: a low dose group receiving <= 66 Gy (14) and a high dose group receiving > 66 Gy (11). 11 patients (10 stage III, 1 stage I) received chemotherapy prior to FSRT (9 in the low dose and 2 in the high dose group). Results: The mean dose delivered was 61.7 Gy in the low dose group and 89.9 Gy in the high dose group. In the low dose cohort the results were: 4 CR, 7 PR, 2 SD and 1 PD. In the high dose cohort we observed 6 CR, 3 PR, 2 SD and 0 PD. The outcome was better with higher doses, the results were statistically significant (Chi_: P = 0.039). 8 patients had a local relapse, 6 in the low dose and 2 in the high dose group. Conclusion: There is a positive dose-response correlation for FSRT in NSCLC.
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ORAL SESSIONS 15h00 - 16h00
VESTIBULAR SCHWANNOMAS 2 OS6 Chairmen: L. Dade, Lunsford; Roberto, Spiegelmann Room Nation
Radiosurgery of facial neurinoma - Long-term results and functional outcome OS6-1 Yoshihisa, Kida (1) (1) Komaki City Hospital - Department of Neurosurgery Komaki Aichi, Japan Since 1991, fifteen cases of facial neurinoma have been treated with gamma knife. There are 6 males and 9 females, ages ranged from 28 to 70 years with a mean of 46 years. Many of them complained of facial palsy or hearing disturbance. Majority of the tumors are located in internal meatus(2), geniculate gangliona and middle fossa (8) or in CP angle (4). Some are extending into cavernous sinus (1). Tumor size at radiosurgery are ranged from 12 to 34 mm with a mean diam- eter of 20.5 mm(mean volume: 5.84 cc). At radiosurgery tumors were treated with a mean max- imum dose of 24.2 Gy and a marginal dose of 12.9 Gy (range:11-16 Gy). In the mean follow-up of 28.3 months, 8 cases showed PR, 2 cases disclosed MR and 5 cases are unchanged in size. Thus the response rate and the control rate are 53% and 100% respectively. Hearing disturbance are generally unchanged, but facial palsy are either improved(33%) or unchanged(53%) except for worsening in one case just after the treatment. As adverse effects, hydrocephalus and a wors- ening of facial palsy.were seen in one case each. In conclusion, radiosurgery for facial neurinoma is apparently useful and better than the results of operation in terms of tumor control as well as functional outcome. Small tumor less than 30 mm in mean diameter, recurrent or residual tumor after operation should be treated with radiosurgery.
Risk of malignancy in the radiosurgical management of Type 2 Neurofibromatosis (NF2) OS6-2 Jeremy, Rowe (1); Alison, Grainger (1); Lee, Walton (2); Aurelia, Kollova (1); Matthias Walter Richard, Radatz (3); Andras A, Kemeny (1) (1) Royal Hallamshire Hospital - National Centre For Stereotactic Radiosurgery; (2) University of Sheffield - Department of Medical Physics and Clinical Engineering; (3) Royal Hallamshire Hospital - Department of Neurosurgery Sheffield, United Kingdom Introduction: Whilst minimally invasive radiosurgical treatments are clearly an attractive manage- ment strategy in NF2, there is obvious concern about the use of radiation in a condition arising from tumour suppressor gene mutations. Clinical material: In our systematic study cross-referenc- ing radiosurgery patients with national mortality and cancer databases, we identified 118 patients with NF2, who underwent 144 radiosurgical treatments for 146 vestibular schwanno- mas (VS), 23 meningiomas and 4 other tumours. This constitutes 906 patient-years of follow-up from first radiosurgical treatment. The mean±SD age at diagnosis was 25±12 years, and at treatment 32±14 years. Results: Two new malignant intracranial tumours were reported after radiosurgery. One, previously reported, was a rapidly growing VS before radiosurgery, which at subsequent resection had malignant histology.[1] The other was a glioblastoma reported three 125 Oral Presentations Abstracts
years after VS radiosurgery. Discussion: The significance of detecting these malignant tumours is difficult to evaluate. One was rapidly growing before radiosurgery, and 4% of NF2 patients devel- op gliomas.[2] Furthermore, with an average interval between diagnosis and radiosurgical treat- ment of 7 years, and a mean follow-up from radiosurgery in excess of a further 7 years, these data nearly cover the natural history of the condition. The mean age at death in NF2 has been reported as 36 years, an average of 15 years from diagnosis, 98% of deaths being from NF2 relat- ed complications.[2] Certainly the incidence of malignancy is no greater than the 2.4% mortality quoted in the largest NF2 VS surgical series.[3] Considering these factors, we believe that radio- surgery remains a useful management option for selected NF2 patients. 1. Bari ME et al. Br J Neurosurgery 2002, 16:284-9. 2. Evans DGR et al. Q J Med 1992, 304:603-18. 3. Samii M et al. Neurosurgery 1997, 40:696-706.
Histopathological observations on vestibular Schwannomas following gamma knife radiosurgery OS6-3 Gyorgy, Szeifert (1); Dominique, Figarella-Branger (2); Pierre-Hugues, Roche (3); Marc, Levivier (4); Jean, Regis (5) (1) National Institute of Neurosurgery of Budapest; (2) CHU La Timone - Department of Pathology and Neuropathology; (3) CHU La Timone - neurochirurgie; (4) Hôpital Erasme - Centre Gamme Knife; (5) CHU La Timone - Service de Neurochirurgie Marseille, France Background: Although the number of treated cases has been increasing continuously we know relatively little about the biological effect of high dose irradiation on vestibular schwannomas (VSs) following radiosurgery. The purpose of this study was to analyze histopathological changes in VSs after Leksell gamma knife (LGK) radiosurgery. Methods: Surgical pathology material from 20 cases (17 from Marseille, 3 from Brussels) who underwent craniotomy following radiosurgery were studied. Routine histological and immunohistochemical investigations were performed on the tissue samples. Histopathological findings were compared with clinical and radiological fol- low-up data. Results: Coagulation necrosis in the central part of the schwannomas surrounded with a transitional zone containing loosened tissue structure of shrunken tumor cells covered with an outer capsule of vigorous neoplastic cells was the basic histopathological lesion. Granulation tissue proliferation with inflammatory cell infiltration, different extent of hemorrhages and scar tis- sue development was usually present. Endothelial destruction or wall damage of vascular chan- nels was a common finding. Analyzing the follow-up data it turned out that 7 patients out of the 20 were operated on because of radiological progression only without clinical deterioration and 4 of them was removed during the latency period after radiosurgery. Conclusion: Results of the present histopathological study suggest that radiosurgery works with double effect on VSs: it seems to destroy directly tumor cells (with necrosis or inducing apoptosis), and causes vascular damages as well. The loss of central contrast enhancement on CT and MR images following radiosurgery might be consequence of necrosis and vascular impairment. From clinical-patholog- ical point of view we think that patients should not undergo craniotomy just because of radiolog- ical progression of the tumor without clinical deterioration, mainly in the latency period.
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Avoidance of facial nerve dysfunction after GK radiosurgery: modified dose planning technique OS6-4 Masaaki, Yamamoto (1); Bierta E. Barfod (1); Yoichi, Urakawa (1) (1) Katsuta Hospital - Mita Gamma House Hitaxhi-Naka, Japan Introduction: GK radiosurgery is currently being used for primary or postoperative management in an increasing number of vestibular schwannoma (VS) patients. Early GK radiosurgery experi- ences included post-treatment facial nerve (VII) complication incidences of 3% or slightly more. In 1995, when the Leksell GammaPlan System (Elekta, AB, Stockholm) became available, the authors modified a dose planning technique to reduce VII dysfunction rates. Patients and Techniques: The greater part of a tumor is covered with a 12 Gy isodose gradient while the ante- rior part of the intracanal portion and a small anterior-superior region of the cisternal portion are covered with a 10 Gy isodose gradient. Using this modified dose-planning technique, the authors have treated 191 VS patients during the 10-year period since 1995. Results: In our initial series of 120 patients who underwent GK radiosurgery before March of 1992 (follow-up period of 3 years or more), rates of tumor control and a preservation of serviceable hearing were was 97.5% and 55.0%, respectively. A V-P shunt procedure was required for post-GK hydrocephalus in 5.8%. However, in the entire group of 191 patients, no additional permanent VII dysfunction occurred and only one experienced transient deterioration of VII function, which appeared after partial removal of the tumor but had subsided by the time of GK. Conclusion: Using this dose planning technique, the risk of postradiosurgical VII dysfunction can be virtually eliminated without increas- ing the risk of tumor control failure.
LUNG TUMORS 2 OS7 Chairmen: Ingmar, Lax; Paul, VanHoutte Room Permeke & Rembrandt
Dosimetric validation of a breathing synchronized irradiation technique for hypofractionated lung treatments OS7-1 Dirk, Verellen (1); Koen, Tournel (2); Nadine, Linthout (3); Guy, Storme (4) (1) AZ VUB - Physique; (2) AZ-VUB - Radiotherapy; (3) AZ-VUB - Radiotherapy; (4) AZ-VUB - Radiotherapy Brussels, Belgium Background and Purpose: Evaluation of the technical feasibility of a prototype developed for breathing synchronized irradiation in combination with intensity modulated radiation therapy. Material and Methods: DMLC-IMRT fluence patterns acquired on radiographic film, generated by the linac in non-gated and gated mode, have been imported into the initial TPS. The effect of pos- sible interplay between organ motion and leaf motion and the efficacy of a breathing synchro- nized irradiation technique (an adapted version of a commercially available image-guidance sys- tem: NOVALIS BODY / ExacTrac4.0, BrainLAB AG) has been evaluated using radiographic film mounted to a simple phantom simulating a breathing pattern of 16 cycles per minute and cover- ing a distance of 4 cm to obtain the resulting fluence maps. Additional ionization chamber meas- urements have been performed using the same cycling phantom. Two situations have been inves- tigated: (a) A tumor located close to the diaphragm to assess the influence of organ motion on the dose to the target volume as well as to the gastro-intestinal tract that presents a high risk at 127 Oral Presentations Abstracts
intersecting with the beam during the breathing cycle. (b) A thoracic lesion requiring complicat- ed fluence patterns to assess the possible interplay between leaf motion and organ motion. Results: Importing measured fluence maps yielded highly disturbed reconstructed dose distribu- tions in case of the non-gated delivery with the phantom in motion (both orthogonal and paral- lel to the leaf direction), whereas the measurements from the static (film fixed in space) and the gated delivery showed good agreement with the original theoretical dose distribution. These findings have been confirmed by the dose-volume histograms, corresponding tumor control prob- abilities (almost identical for the original, static and gated measurements; yet reduced with a fac- tor 2 for the “in motion and non-gated” delivery), conformity index and dose heterogeneity val- ues (increased with a factor 3 to 6 -depending on the case- when motion was induced, where- as again similar values have been obtained applying the original, static and gated fluence maps). The normal tissue complication probability seems to be affected to a lesser degree, which con- curs with the observation that the interplay effects result in a dose spread in the direction of motion. Ionization chamber measurements yielded a dose reduction exceeding 50% when motion is involved, which restored within 5% of the prescribed dose applying breathing synchro- nized irradiation. The applied breathing synchronization technique introduced an increased treat- ment time with a factor 3 to 4. Conclusions: The use of measured fluence fields, delivered by the linac in non-gated and gated mode, as imported fluence maps for the treatment planning system is an interesting quality assurance tool and revealed the dramatic impact of interplay between DMLC-IMRT dose delivery and organ motion, as well as the advantage of breathing synchroniza- tion to resolve this issue. The latter should, however, be outweighed against the increased treat- ment time.
Stereotactic body radiation therapy for lung metastases: Impact on overall survival OS7-2 Martin, Fuss (1); Charles R., Thomas Jr. (1); Bill J., Salter (2); Terence S., Herman (1) (1) UTHSC San Antonio - Radiation Oncology; (2) Cancer Therapy & Research Center - Medical Physics San Antonio , USA Hypofractionated or single dose stereotactic body radiation therapy (SBRT) for a limited number of lung metastases has been documented to be feasible and to yield excellent local tumor con- trol. The aim of this analysis was to determine if SBRT contributes to prolonged survival in a patient population with systemic disease manifestation. Between 8/01 and 11/04, 50 patients were treated by SBRT for lung metastases (1-4 metastases, median 1) with maximum diameter <6 cm. A sequential tomotherapeutic intensity-modulated radiation technique (Peacock IMRT, Nomos) was used to deliver 3 fractions of 12 Gy (total dose 36 Gy). Doses were prescribed as the minimum dose to the planning target volume (PTV) which included safety margins of 5 mm axi- ally and 10 mm cranio-caudally to the gross tumor volume (GTV). We analyzed overall survival in this population. Results: The median GTV and PTV treated was 16 and 43 cm3 (range GTV: 1- 135 cm3; PTV: 12-256 cm3). At a respective mean and median clinical follow-up of 10.2 and 7.4 months, 10 patients have expired. Median time to death was 3.6 months. Cause of death was new metastatic disease to lung, liver and/or brain. At the time of death, 8/10 patients had doc- umented local control of SBRT treated lesions. Follow-up in patients alive ranges from 2.5 to 34 months (mean 9.9, median 7.7 months). Of 41 patients treated at least 12 months prior to analy- 128 Oral Presentations Abstracts
sis, 31 were alive at last follow-up. Of those, 21 patients were alive with imaging confirmed sys- temic disease progression, including 2 with local recurrence or lack of response to SBRT. Conclusions: SBRT in patients with a limited number of pulmonary metastases results in encour- aging preliminary survival rates and may result in an increased intermediate-term survival for a subset of patients. However, cause of death in the majority of cases was systemic disease pro- gression indicating that SBRT can only be one tool in the multi-disciplinary disease management for this patient population.
Metabolic PET imaging for stereotactic body radiation therapy planning and therapy response assessment of pulmonary malignancies OS7-3 Martin, Fuss (1); Bill J., Salter (2); Terence S., Herman (1); Charles R., Thomas Jr. (1) (1) UTHSC San Antonio - Radiation Oncology; (2) Cancer Therapy & Research Center - Medical Physics San Antonio, USA Target delineation for lung SBRT is typically based on CT imaging. Metabolic tumor information derived from FDG-PET may allow to more accurately target pulmonary malignancies and to assess tumor response. Between 5/02 and 11/04, 38 patients underwent FDG-PET imaging in addition to CT simulation for lung SBRT. Tomotherapeutic IMRT was used to deliver 3x12 to 3x20 Gy (total doses: 36 Gy (metastases) and 48-60 Gy (stage 1 NSCLC). We analyzed the impact of metabolic image information on target delineation. Additionally, 30/38 patients had PET studies acquired at 4 to 12 weeks following SBRT, and 18 patients had additional PET studies acquired at 6 to 28 months of follow-up. A pathologic SUV of >3.0 at baseline was observed in 35/38 studies. FDG- PET metabolic information changed the GTV in 8/34 cases where tumor associated lung atelec- tasis or regional fibrosis was observed. Here, the FDG uptake region was used for GTV delin- eation. Changes in tumor SUV were observed as early as 4 weeks following SBRT. A decline to SUV <3.0 was consistently observed at 12 weeks (28/30 patients with PET follow-up, including 2/3 patients with low initial SUV showing minor decline). In long-term PET follow-up, further reduction in uptake to normal tissue levels was observed. Two patients who failed to show a decline in FDG uptake failed SBRT locally. Although the small patient number studied may limit our ability to comprehensively assess the value of implementing FDG-PET into SBRT treatment planning and therapy response assessment for pulmonary malignancies, our preliminary experi- ence supports three conclusions: (1) FDG-PET may be especially useful for SBRT planning of lesions masked by fibrosis, or atelectasis; (2) early decline in FDG uptake may prognosticate long- term local tumor control; (3) lack of SUV decline within 12 weeks may precede local failure.
Computed tomographical analysis of radiation sequelae due to experimental stereotactic irradiation to normal rabbit lung OS7-4 Takatsugu, Kawase (1); Etsuo, Kunieda (2); M Deloar, Hossain (2); Satoshi, Seki (2); Akitomo, Sugawara (2); Tatsuya, Fujisaki (3); Akitoshi, Ishizaka (4); Atsushi, Kubo (2) (1) Keio University - Department of Radiation Oncology, (2) Keio University - Department of Radiology, (3) Ibaraki Prefectural University of Health Sciences - Department of Radiological Sciences, (4) Keio University - Department of Medicine Background: Stereotactic irradiation (STI) to treat early non-small cell lung cancer in Japan may be a possible alternative to surgical treatment. We tried to establish an STI technique by irradiating 129 Oral Presentations Abstracts
normal rabbit lung and examining the radiation sequelae using computed tomography (CT) images. Materials and Methods: Institutional guidelines for the care and use of laboratory ani- mals were followed in all experiments, and the use of rabbits was approved. Seven Japanese White Rabbits were anesthetized and partial spherical volume of each left lung was stereotacti- cally irradiated with 4 MV of X-ray energy with a narrow beam of size 11mm x 11mm. Three non- coplanar arcs (couch rotation: 0 deg ± 45 deg) were employed for arc rotation. Each gantry rota- tion arc was 160 deg. Total irradiated dose of each rabbit was 21, 30, 39, 48, 60, 60, 60 Gy, respectively. After the irradiation, each rabbit was scanned with a CT scanner approximately biweekly. All rabbits were examined for 24 weeks after irradiation. Round regions of interest, cor- responding to the stereotactically irradiated area and the comparable part of the contralateral lung were delineated on CT image viewer. The ratio of CT values (irradiated part to comparable part of the contralateral normal lung) was calculated for each scanned rabbit lung image. Additionally the ratio after irradiation was divided by the ratio before irradiation and used to com- pare seven time course variations under the same conditions. Results: Localized attenuating opac- ities suggesting emphysematous change appeared consistently in the irradiated parts of several rabbits 7-14 weeks after irradiation. The findings persisted after then. The time course curve of the ratios was variable and indicated no significant regularity. Conclusions: Though the single dose of STI was high, the sequelae were subtle. Rabbit lung might be more tolerant to acute and subacute radiation effects than human lung.
ORAL SESSIONS 17h00 - 18h00
VESTIBULAR SCHWANNOMAS 3 OS8 Chairmen: L. Dade, Lunsford; Jean, D’Haens Room Nation
Five session gamma knife treatment of acoustic neuromas OS8-1 Steven, Cobery (1); Melissa, Remis (2); Carla, Bradford (2); Georg, Noren (2) (1) Brown University - Department of Neurosurgery; (2) Rhode Island Hospital, Brown University - New England Gamma Knife Center Providence, USA Purpose: To assess the tumor volume control and hearing preservation after gamma knife frac- tionated radiosurgery (GKFR) for acoustic neuroma. Methods: Between May 1999 and February 2004, 25 patients with unilateral acoustic neuromas underwent a fractionated radiosurgical pro- tocol using the Leksell gamma knife (Elekta Instruments, Inc., Norcross, GA). Mean tumor diam- eter ranged from 9.1 to 36.0 mm. The fractions were given daily over 5 consecutive days. The stereotactic coordinate frame was affixed prior to the first fraction on Day 1 and removed follow- ing the last fraction on Day 5. A fraction dose of 3 Gy was prescribed to 48 - 50%, for a total dose of 15 Gy. Conformality was assured through the use of multiple isocenters, averaging 22 isocenters per patient (range 5-44) per fraction. Tumor size was measured on preoperative and follow-up MRI. Gardner-Robertson (GR) scale was used to classify hearing. Followup, which entailed clinical examination by a physician, MRI, and audiometric testing, occurred at 6 month intervals for the first year and annually thereafter. Failure of local control of tumor size was defined as the need for any additional intervention, including open resection, additional radiosurgery/therapy, or any combination of the two. Results: Follow-up ranged from 12 to 64 130 Oral Presentations Abstracts
months postoperatively. Tumor control was achieved in 96% of cases. Hearing preservation in the serviceable range (Gardner Robertson scale of I or II) was achieved in 86% of cases. One patient experienced a transient, postoperative tinnitus, which resolved after a course of steroids. No facial or trigeminal neuropathy occurred postoperatively. Conclusion: GKFR may provide greater poten- tial for the preservation of hearing by ensuring precision and conformality not available with other stereotactic radiosurgical or radiotherapeutic systems. This fractionated radiosurgical procedure seems to offer increased protection of surrounding neural structures, particularly hearing system, in comparison to other techniques.
Evaluation of ophthalmological consequences of gamma knife radiosurgery in vestibular schwannomas OS8-2 Manabu, Tamura (1); Noriko, Murata (2); Motohiro, Hayashi (3); Jean, Regis (4) (1) Timone University Hospital - Stereotactic and Fonctional Neurosurgery; (2) Timone University Hospital - Stereotactic and Fonctional Neurosurgery; (3) Tokyo Women's Medical Univeristy - Department of Neurosurgery; (4) CHU La Timone - Service de Neurochirurgie Marseille, France Objective : Due to the synergic role of the facial nerve and the nervus intermedius in the mechan- ical protection of the eye, Vestibular Schwannomas (VS) and/or their treatment are dangerous for the visual function. Our goal is to evaluate the subjective and objective impact of the gamma knife Radiosurgery (GKS). Material and Method : A functional questionnaire evaluating among other items the patient complaints related to the eye has been addressed to a series of 100 patients 3 years after the GKS, of a unilateral VS and not previously operated. Schirmer’s test was addition- ally performed before GKS and more than 2 years after GKS to evaluate the injury of the lacrimal component of the nervus intermedius in 66 patients. Results : Among 68 patients responding to the questionnaire, 9 (13.2%) patients complained of dry eye, 10 (14.7%) pts. of burning eye, 1 (1.5%) pt. of crocodile tears and 10 (14.7%) pts. of eye crying after GKS. No patients had new facial motor palsy after GKS. In 64 patients with no facial palsy before (nor after) GKS, a dry eye is reported in 8 (12.5%), a burning eye in 9 (14.1%), crocodile tears in 1 (1.6%) and eye crying in 9 (14.1%) after GKS. Thus patients with no clinical signs of impairment of the VII motor nerve are presenting in 14% of cases sign of indicating the injury of the intermedius nerve. In the Schirmer test before GKS, 27 of 66 (40.9%) patients had already showed the abnormal lacrima- tion that means less lacrimation in the tumour side than the contra lateral side. As we followed the patients for 4.8 years after GKS, 51 patients resulted in normal lacrimation, while 15 cases (22.7%) remained abnormal function (4 cases) or deteriorated (11 cases), which indicates the patients of abnormal lacrimation decreased after GKS significantly (Chi-test, p=0.0249). We also examined the predictive factor that might cause the result of the Schirmer test after GKS in the treatment of VS. Among the variates before GKS, abnormal lacrimation, facial motor palsy, hypoesthesia, sex, tumour size, age, dose rate of GKS, tumour volume, peripheral and maximum dose of GKS were analyzed. Patients presenting with an infraclinical injuries of the lacrimal com- ponent of the intermedius nerve before GKS, have a higher possibility to suffer from a clinical signs specially dry eye after GKS (Chi-test, p=0.021). Conclusions : This study is the first demon- strating that Radiosurgery can improve or impair nervus intermedius function in non-rare percent- age of cases. Sub-clinical evaluation before GKS on the nervus intermedius predict the ocular symptom after GKS and must be part of all evaluation before and after radiosurgery in VS. 131 Oral Presentations Abstracts
Relative safety of gamma knife radiosurgey in CPA angle tumors with significant brainstem compression OS8-3 Mohammad Ali, Bitaraf (1); Mazdak, Alikhani (2); Mazyar, Azar (3); Frarid, Kazemi (4) (1) Tehran university of medical sciences - Neurosurgery; (2) Tehran university of medical sciences - Neurosurgery; (3) Iran university of medical sciences - neurosurgery; (4) Iran university of medical sciences - Neurosurgery Tehran, Iran Significant brain stem compression is considered to be a relative contraindication for radio- surgery,due the risk of possible brain stem radiation changes and also adverse effect of progres- sion and mass effect of tumor on the brain stem.In the present report we investigated 80 menin- gioma and acoustic schwanoma patients in whome moderate to sever compression of brain stem was present.Clinical studies showed that patients presented with a comparable spectrum of signs and symptoms regardless of th degree of compression possibly due to the plasticity of CNS neu- rons.Patients underwent radiosurgery using leksell model C gamma knife unit and were followed up for a median of six months. A grading system was develpoed and degree of brain stem dis- tortion was graded as a 1+ to 4+ grade. No case had pre-radiosurgery brain stem edema .Among the 95 patients, no pateints showed post-operative brain stem radiation changes.Clinical conditions of the pateints were either improved or unchanges following radiosurgery in 76 patients .In the relatively short period follow-up only 4 patient deveolped new signs or symptoms as a consequence of brain stem compression.One patient required urgent microsurgery 6 months after treatment despite tumor shrinkage in MRI.All four patients with new neurological symptoms were in grade 4 of brain stem compression according to our grading system.In the subset of patients with follow-up imaging,evidence of intratumor necrosis or reduction in tumor size was present in 85% of cases.Our results indicate that brain stem compression might be considered as a relatively safe alternative to the microsurgery specially in under-developed countries were skull base microsurgery poses multiple dilemmas.
Hypofractionated stereotactic radiotherapy as primary treatment of acoustic neuroma: Interim results of the Johns Hopkins experience OS8-4 Ori, Shokek (1); Stephanie, Terezakis (1); Michael, Hughes (1); Lawrence, Kleinberg (1); Moody, Wharam (1); Daniele, Rigamonti (2) (1) The Johns Hopkins University School of Medicine - Department of Radiation Oncology and Molecular Radiation Sciences; (2) Johns Hopkins University School of Medicine - Department of Neurosurgery Baltimore, USA Purpose/Objective: To report our institution’s experience in the primary treatment of acoustic neu- roma with hypofractionated stereotactic radiotherapy, specifically in regard to rates of local con- trol, hearing preservation, and facial nerve injury. Materials/Methods: Between November 1995 and March 2003, 375 radiographically diagnosed acoustic neuromas were treated in 373 evalu- able patients (two patients with type II neurofibromatosis received bilateral treatment). The medi- an age of the entire cohort was 53 yr (mean 53 yr; range 17–86 yr). Patients were treated with 6 MV or 10 MV linac stereotactic radiotherapy. Three fractionation protocols were utilized, and the choice of protocol was influenced by tumor dimensions, as follows: (a) The most common protocol, used in 333 tumors, was 25 Gy in five daily fractions. In patients treated using this pro- tocol, the median maximal tumor diameter was 15.0 mm (mean 15.6 mm; range 1.8–36 mm), 132 Oral Presentations Abstracts
and the median contoured volume was 0.69 cc (mean 1.8 cc; range 0.02–14.4 cc). (b) 30 Gy in 10 daily fractions was used in 37 tumors, with a median maximal tumor diameter of 31.0 mm (mean 32.0 mm; range 12–42 mm) and a median contoured volume of 10.7 cc (mean 11.1 cc; range 1.1–20.2 cc). (c) 40 Gy in 20 daily fractions was used in 4 tumors, with a median maximal tumor diameter of 37.5 mm (mean 36.5 mm; range 31–40 mm) and a median contoured tumor volume of 21.3 cc (mean 22.5 cc; range 21.1–26.3 cc). A single patient (whose tumor measured 10 mm/0.07 cc) did not complete treatment; she received 16.7 Gy in three fractions, and treat- ment was halted because of the on-treatment onset of CN VII palsy. Results: With a median fol- lowup interval of 21 months (mean 24 months; range 2–96 months), local regrowth was seen in 12 cases, documented at a median post-treatment interval of 28.1 months (mean 28.9 months; range 12.0–42.2 months). The median pre-treatment maximal diameter in these cases was 20.0 mm (mean 19.25 mm; range 9–31 mm; raw data 9, 13, 13, 15, 18, 20, 20, 22, 22, 23, 25, and 31 mm), and the median pre-treatment contoured volume was 1.95 cc (mean 3.47 cc; range 0.27–9.21 cc; raw data 0.27, 0.31, 0.69, 1.01, 1.15, 1.60, 2.29, 5.81, 6.22, 6.35, 6.74, and 9.21 cc). The Gardner-Robertson classification was used for audiologic evaluation. Pre- and post-treatment data were available for 212 patients, with a median audiologic followup of 15.8 months (mean 18.1 months; range 1–60 months). Serviceable hearing was defined as Gardner-Robertson class (GRC) 1 or 2. There were 150 patients with serviceable hearing pre-treat- ment, of whom 89 (59%) retained serviceable hearing post-treatment. There were 62 without serviceable hearing pre-treatment, of whom 8 (13%) gained serviceable hearing post-treatment. Those with pre-treatment GRC 1 (n = 106) had median change of -1 GRC (mean _1.0). Those with pre-treatment GRC 2 (n = 44) also had a median change of _1 (mean _1.0). Those with pre-treatment GRC 3 (n = 35) had a median change of zero (mean _0.5). Two patients with pre- treatment GRC 4 both gained 1 GRC. Those with pre-treatment GRC 5 (n = 25) had a median change of zero and a mean change of +0.9. Cranial nerve VII deficits were noted in eight patients and resolved in all except two. Conclusions: Hypofractionated stereotactic radiotherapy as primary treatment of acoustic neuroma, with interim followup, provides a high rate of local control, with moderate hearing preservation and rare facial nerve injury.
OTHER TUMORS OS9 Chairmen: Ingmar, Lax; Rita, Engenhart-Cabillic Room Permeke & Rembrandt
Epidermoid cyst treated with gamma knife radiosurgery OS9-1 Jeremy, Ganz (1); Ayman, Hafez (1); W A., Reda (1) (1) Cairo Nasser Institute - Gamma Knife Center Cairo, Egypt Objective: To recount the case history of the first patient with an epidermoid cyst to be treated with radiosurgery. Case Material: The patient was a 9 year old young lady who presented with a history of recurrent attacks of meningitis every 3 weeks. She was found to have a lesion between the pons, medulla and the clivus. This was operated twice but some cyst material had to be left behind because of adherence to nerves and blood vessels. Further surgery was considered inad- visable. A review of the literature produced one case with the same diagnosis, where a positive response to radiotherapy had been achieved. It was considered this little girl had nothing to lose 133 Oral Presentations Abstracts
by being treated. Results: The patient was treated on the September 2003. The 1.7 cm3 lesion received 12 Gy to the 55% isodose with 92% cover and a conformity index of 1.25. She has been followed for 15 months. Since treatment she has only had one attack of meningitis in November 2003 a few weeks after the gamma knife. Since then there have been no attacks. At follow up in September 2004 the lesion was smaller than at treatment and she was in good health and spir- its. Conclusion: This is a rare condition which may often be impossible to remove in toto because of its adherence to local tissues. In view of the response in this patient it is suggested that gamma knife radiosurgery may be an alternative management. However, it should be explained to the patient and / or family that this treatment is experimental at present and should only be used in patients for whom nothing else is available and who are suffering intolerable discomfort from the lesion.
Stereotactic radiation for cystic craniopharyngiomas OS9-2 Alessandra, Gorgulho (1); Carlos, Mattozo (1); Murisiku, Raifu (1); Katayoun, Tajik (1); Michael, Selch (2); Nzhde, Agazaryan (5); Timothy, Solberg (5); Daniel, Kelly (1); Antonio, De Salles (1) (1) UCLA Medical Center - Department of Neurosurgery; (2) UCLA Medical Center - Department of Radiation Oncology Los Angeles, USA Purpose: Craniopharyngiomas cysts are challenging since recurrence is very common with con- ventional approaches. This report evaluates cyst control after stereotactic radiation. Materials and Methods: Between July/1996-July/2003, 27 patients with craniopharyngiomas were treated with radiosurgery (SRS)/stereotactic radiation therapy (SRT) at UCLA. Fifteen had predominant cyst component (2 excluded due to incomplete follow-up). Mean age was 44.1 years (9-71y), 7 male:6 female. Eleven presented with visual deficits (84.62%), 8 headaches (61.54%), 4 mental confusion (30.77%), 2 hypopituitarism(15.38%). Nine (69.23%) underwent transnasal transphe- noidal surgery(TNTS), 7(53.85%) craniotomy, 5(38.46%) stereotactic drainage(SD) prior and/or after SRT. Two(15.38%) cases had radiological total resection confirmed. All but one received SRT. Mean SRT maximal dose of 45.8Gy (12.6-54Gy) was prescribed to mean 90±3.13 isodoseline. Mean fractions were 25.5±5.77 (8-30). SRS maximal dose was 22.86Gy. Mean initial tumor vol- ume was 14.86cc (1.77-47.45cc). Mean follow-up was 40.67±21.9 months (10-90 months). Results: Cyst control rate was 92.3%. Final mean cyst volume was 0.55±1.24cc while mean pre- radiation cyst volume was 9.41cc(0.95-41.32cc). Initial response was: 8(61.53%) decreased, 1(7.69%) stabilized, 4(30.8%) increased. Two of these patients underwent placement of Rickman reservoir, one had stereotactic followed by TNTS drainage. The fourth deceased 7 months after SRT. Mean volume aspirated was 16cc (2-25cc). Mean SRT-SD interval was 43.8 days (1-90days). Final cyst response was: 5 (38.46%) disappeared, 6(46.15%) decreased from which 2(15.38%) collapsed, 1(7.69%) remained stable and 1 increased (deceased patient). Time to final cyst response was 288.22±307.78 days (27-1029 days). Visual improvement occurred in 4 (31%) cases, 69% remained stable. Two (15.38%) developed hypopituitarism. One reservoir was removed due to infection. Conclusions: The excellent cyst control achieved suggests that stereo- tactic radiation should be the treatment of choice for residual/recurrent cysts, especially in a pop- ulation already submitted to multiple prior procedures. The radiation response is not always immediate, so drainage may be necessary until cyst is controlled. 134 Oral Presentations Abstracts
Radiosurgery of epidermoid tumor - Trial for radiosurgical nerve decompression OS9-3 Yoshihisa, Kida (1) (1) Komaki City Hospital - Department of Neurosurgery Komaki Aichi, Japan Long-term results of radiosurgery for epidermoid tumors are reported. There are 8 cases includ- ing 3 males and 5 females, ages ranging from 6 to 63 (mean: 37.8 years). At radiosurgery whole tumor was covered in 4 and partially covered in 4 for the attempt of relieving cranial nerve signs like trigeminal neuralgia (5 cases) and facial spasm (1 case). The mean maximum and marginal dose were 27.1 Gy and 14.6 Gy respectively. In the mean follow-up of 42.8 months, all the tumors showed a good tumor control without any progression and tumor shrinkage is confirmed in 2 out of 8 cases. Among them symptomatic trigeminal neuralgia improved or disappeared in all 5 cases who complanied of before radiosurgery, and facial spasm disappeared in one. No neu- rological deterioration was found in any case after the treatment. In conclusion it is apparent that epidermoid tumors do respond well to radiosurgery and the accompanying hyperactive dysfunc- tion of cranial nerves are significantly improved by gamma knife treatment either with entire or partial tumor coverage. Therefore the radiosurgical nerve decompression for epidermoid tumor is seemingly achieved by gamma-radiosurgery.
Fulminate peritumoral brain edema following radiosurgery for meningiomas: Report of two cases and review of the literature OS9-4 Guus, Koerts (1); Dirk, Van Den Berge (2); Christian, Raftopoulos (3); Jean, D'Haens (4) (1) Cliniques Universitaires Saint-Luc - Neurosurgery; (2) AZ VUB - Radiothérapie; (3) Cliniques Universitaires Saint-Luc - Neurochirurgie; (4) AZ VUB - Neurochirurgie Brussels, Belgium Introduction: Resection of skull base meningiomas remains difficult and is associated with signif- icant morbidity. Radiosurgery is an excellent alternative and high tumor control rates with mini- mal morbidity have been reported. Nowadays radiosurgery is also performed for superficially located meningiomas. We report two cases of fulminate edema after radiosurgery and review the literature analysing the risk factors. Case reports: The first patient had a recurrent parietal parasagittal meningioma despite postoperative fractionated radiotherapy. Three months post radiosurgery he developed headache and hemiparesis due to peritumoral edema. The second had an asymptomatic occipital parasagittal meningioma and was treated by radiosurgery on her request. Seven months later she developed peritumoral edema with hemiparesis and confusion. Both received 14Gy on the 80% isodose line and recovered completely after administration of steroids. Discussion: Several reports concerning tumor control (95%), outcomes, and complica- tions after meningioma radiosurgery have been published. Cranial nerve deficit or carotid artery stenosis are reported after radiosurgery for cavernous sinus meningiomas. Peritumoral brain edema following radiosurgery for skull base meningiomas is rare(1-6%). However in non-basal meningiomas( convexity) edema is reported in 5%-50% of cases. It typically appears after a laten- cy period 3-8 months. Duration and severity of symptoms can be troublesome but most patients will recover after administration of oral steroids. Radiosurgical parameters have been examined to explain this phenomenon. Tumor volume, tumor margin dose, tumor maximum dose, and dose 135 Oral Presentations Abstracts
to adjacent brain were not statistically correlated to edema post-radiosurgery. The only significant factor seems to be tumor location. Peritumoral edema is most prominent in convexity menin- giomas. Unlike skull base meningiomas,which are surrounded by cisterns, hemispheric menin- giomas lack any intervening arachnoid or cerebral spinal fluid barrier between the tumor and cor- tical surface. Conclusion: Radiosurgery of convexity meningiomas is not without complications and primary surgery should be considered whenever possible.
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Tuesday 13/09/05
PLENARY SESSION 8h45 – 10h00
PS2 Room Nation DATA BLITZ UPDATE 1 Extracranial Radiosurgery PS2-1 Ingmar, Lax
DATA BLITZ UPDATE 2 Vestibular Schwannomas PS2-2 L. Dade, Lunsford
BRAIN METASTASES Chairmen: Ingmar, Lax; L. Dade, Lunsford
Radiosurgery for the treatment of 239 patients with brain metastases: estimation of patients eligibility using three stratification systems PS2-3 Daniel, Devriendt (1); José, Lorenzoni (2); Nicolas, Massager (3); Philippe, David (4); David, Wikler (5); Daniel Salvador, Ruiz Gonzalez (6); Bruno, Vanderlinden (7); Paul, Van Houtte (1); Jacques, Brotchi (3); Marc, Levivier (2) (1) Institut J. Bordet - Radiothérapie; (2) Hôpital Erasme - Centre Gamme Knife; (3) Hôpital Erasme - Neurochirurgie; (4) Hôpital Erasme - Neuroradiologie; (5) Hôpital Erasme - PET Scan; (6) Medica Sur SA de CV MSU 820125 T58 - Unidad Gamma Knife; (7) Institut J. Bordet - Physique Brussels, Belgium Objective: To test three patients’ stratification systems, the recursive partitioning analyze (RPA), the score index for radiosurgery in brain metastasis (SIR) and a newly proposed Basic Score for Brain Metastases (BS-BM), as predictors of survival, that could help in patient’s selection. Materials and methods: Between December 1999 and May 2005, 239 patients with 606 brain metastases were treated with a gamma knife C. Median marginal prescription dose was 20 Gy, at a median 50% isodose. BS-BM was calculated evaluating 3 main prognostic factors: Karnofsky status 80 or more, control of primary tumor, and existence of extracranial metastases. Results: Median survival was 23 months for RPA class I, 13 months for class II and 3 months for class III, (p<0.0001). According to SIR system, median survival was 21 months, 11 months, 4 months and less than 3 months for scores 8 to 10, 5 to 7, 4 and 0 to 3 respectively, (p< 0.0001). Median survival was 23 months for patients with BSBM 3 points, 13 months with 2 points, 5 months with 1 point , (p<0.0001). Conclusion: RPA, SIR and BS-BM seem to be useful tools to estimate outcome. Among them, BS-BM system is a simple and useful tool for patient’s selection. These systems are also able to identify patients with short survival (SIR 0-3 , RPA III and BSBM 0-1).
137 Oral Presentations Abstracts
Long-term survivors after gamma knife radiosurgery for brain metastases PS2-4 Douglas, Kondziolka (1); Juan, Martin (2); John C, Flickinger (1); L. Dade, Lunsford (1) (1) University of Pittsburgh Medical Center - Department of Neurological Surgery; (2) Department of Neurological Surgery - University of Pittsburgh Pittsburgh, USA Object. Stereotactic radiosurgery, with or without whole brain radiation therapy, has become a valued management choice for patients with brain metastases, although median survivals remain limited. In patients with successful extracranial cancer care, patients who have controlled intracra- nial disease are living longer. We evaluated all brain metastasis patients who lived more than four years after radiosurgery to determine clinical and treatment patterns potentially responsible for their outcome. Methods. Six hundred and seventy-seven patients with brain metastases under- went 781 radiosurgery procedures between 1988 and 2000. We reviewed data from this entire series, and evaluated patients with at least four years survival for information on brain and extracranial treatment, symptoms, imaging responses, need for further care, and management morbidity. These patients were compared to a cohort who lived less than three months after radiosurgery (n=100). Results. Forty-four patients (6.5%) survived more than four years after radiosurgery (mean = 69 months with 16 patients still alive). The mean age at radiosurgery was 53 years (maximum, 72) and the median Karnofsky Performance Score, 90. Lung cancer (n=15), breast (n=9), kidney (n=7), and melanoma (n=6) were the most frequent primary sites. Two or more organ sites outside the brain were involved in 18 patients (41%), the primary plus nodal involvement in 10 (23%), the primary only in 9 (20%), and only the brain disease in 7 (16%), indicating that extended survival was possible even in patients with multi-organ disease. Serial imaging of 133 tumors showed that 99 were smaller (74%), 22 were unchanged (17%), and 12 were larger (9%). Four patients had a permanent neurological deficit after brain tumor manage- ment and six underwent a resection after radiosurgery. In comparison to patients with limited sur- vival (< 3 months), long-term survivors had higher initial Karnofsky Performance Score (p=.01), fewer brain metastases (p=.04), and less extracranial disease (p<.00005). Conclusion. Although the expected survival of patients with brain metastases may be limited, selected patients with effective intracranial and extracranial cancer care can have prolonged, good quality survivals. The extent of extracranial disease at the time of radiosurgery is predictive of outcome, but does not necessarily mean that patients cannot live for years if treatment is effective.
A randomized trial of surgery and radiotherapy versus radio- surgery alone in the treatment of single metastasis to the brain PS2-5 Alexander, Muacevic (1); Berndt, Wowra (1); Joerg, Tonn (2); Hans-Jakob, Steiger (3); Friedrich, Kreth (1) (1) European Cyberknife Center Munich - Cyberknife Center; (2) Ludwig-Maximilians-University, Klinikum Großhadern - Department of Neurosurgery; (3) University Duesseldorf - Department of Neurosurgery Munich, Germany Objective: To assess whether outpatient radiosurgery alone is as effective as surgery and whole brain irradiation (WBRT) for survival and neurologic control of disease in patients with single metastases to the brain. Methods: Sixty-four patients with a single metastasis with a diameter <=3 cm were randomly assigned to either microsurgery followed by whole brain radiotherapy (surgical group, 33 patients) or radiosurgery alone (radiosugery group, 31 patients). All patients 138 Oral Presentations Abstracts
had tumors eligible for radiosurgical treatment. Primary end point was survival, secondary end points were tumor response and local control rates, overall intracranial recurrence rates, cause of death, and quality of life measurements (QL). Survival time was analyzed with the Kaplan Meier method. Prognostic factors were obtained from the Cox model. QL was assessed using the European Organization for Research and Treatment of Cancer Quality of life Questionaire (EORTC QLQ-C30 (+3) and the Brain Cancer Module 20 (BCM20). There was no significant difference between the 2 groups in overall length of survival (9.5 months surgery group, 10.3 months radio- surgery group; p=0.8) and local tumor control (82% surgery group, 97% radiosurgery group; p=0.06). Patients in the radiosurgery group experience more often distant recurrences (p=0.04) which could be effectively controlled with additional radiosurgical treatments. By multivariate analysis survival was similar for RPA class 1 and 2 patients (p=0.12). Unfavorable predictor of survival was a diagnosis of lung cancer (p=0.045). The median neurological death rates were 29% (surgery group) and 16% (radiosurgery group) (p=0.8). Radiosurgery was associated with an improved quality of life 6 weeks after treatment. Overall morbidity were 21.2% (7 patients) in the resection group, and 19.3% (6 patients) in the radiosurgery group, respectively (p>0.1). Conclusions: In selected patients with cancer and single metastases to the brain radiosurgery should be considered as primary treatment option because it is as effective as surgery and radio- therapy and offers a good quality of life.
ORAL SESSIONS 10h30 - 11h30
BRAIN METASTASES 1 OS10 Chairmen: Masaaki,Yamamoto; Minesh, Mehta Room Nation
Recursive partitioning analysis of prognostic factors for patients treated with four or more intracranial metastases treated with radiosurgery OS10-1 Ajay, Bhatnagar (1); Douglas, Kondziolka (2); L. Dade, Lunsford (2); John C, Flickinger (2) (1) University of Pittsburgh Cancer Institute - Radiation Oncology; (2) University of Pittsburgh Medical Center - Department of Neurological Surgery Pittsburgh, USA Objective: The current prognostic recursive partitioning analysis (RPA) system for patients with intracranial metastases is based on prior RTOG trials which primarily involved patients with soli- tary brain metastasis who received whole brain radiation (WB-RT). The purpose of this study is to devise a new RPA classification for patients with four of more intracranial metastases treated with a single stereotactic radiosurgery procedure. Methods: 189 patients underwent gamma knife radiosurgery for four or more intracranial metastases (median = 5, range 4-18) during one session. The median total treatment volume was 6.8 cc (range 0.6-51.0 cc). Radiosurgery was used as sole management (17% of patients), or in combination with WB-RT (46%), or after fail- ure of WB-RT (38%). The median marginal radiosurgery dose was 16 Gy (range 12-20 Gy). Median follow up was 8 months. RPA assessed the effects of age, Karnofsky >70, extracranial disease, visceral metastases, number of metastases, total treatment volume, history of breast and melanoma primaries on survival. Results: The median overall survival after radiosurgery for all patients was 8 months. RPA identified a favorable subgroup of 78 patients (43 % of the entire 139 Oral Presentations Abstracts
series) with a total treatment volume <7 cc and < 7 brain metastases (Class 1), with a median survival of 13 months. The survival of this favorable subgroup was significantly better (p <0.00005) than the remaining patients (Class 2) (n=111) with a median survival of 6 months. Conclusion:The new RPA classification for multiple brain metastasis patients identified Class 1 patients who have a total treatment volume <7 cc and < 7 metastases (4-6) that represent a large subgroup with favorable survival after radiosurgery, who may be reasonable candidates for further clinical studies. Class 2 comprises the remaining patients who have a total treatment vol- ume > 7 cc and/or > 7 metastases who have a significantly poorer survival.
Extracranial tumoractivity determines survival after Gamma Knife radiosurgery for brain metastases OS10-2 Patrick, Hanssens (1); Guus, Beute (2); Theo, Veninga (3); Suente, Lie (2); Koo, van Overbeeke (2); Danielle, Eekers (1) (1) Gamma Knife Center Tilburg - Radiation Oncology; (2) Gamma Knife Center Tilburg - Neurosurgery; (3) Gamma Knife Center Tilburg - Radiation Oncology Tilburg, The Netherlands Objective: To evaluate survival and patterns of failure after radiosurgery for brain metastases (BM). Methods: 275 patients with BM were treated in our center between June 10, 2002 and June 30, 2004. The majority (145/275) had BM from a NSCLC, the second and third most com- mon primary tumor being breast cancer (36/275) and renal cell cancer (28/275). 80% of the patients had ¡Ü 4 BM. Treatment planning was based on T1 weighted MRI with triple dose gado- lineum. A dose of 18-25 Gy was prescribed to the isodose line encompassing ¡_ 90% of the tar- get volume. Radiosurgery was not combined with WBRT. Alle patients had follow-up MRI scans at 3 months interval until death or deterioration of their condition due to untreatable extracranial tumorprogression. If appropriate (no untreatable extracranial tumorprogression) , patients with recurrent intracranial tumor activity received salvage treatment (either surgery, repeated radio- surgery or WBRT). Results: Median survival of the group is 6,96 months with 71% of the patients dying due to extracranial progression. 29% of the patients died without clinical evidence of extracranial progression. The median time to extracranial and intracranial progression is 4,6 and 6,6 months respectively. Survival is significantly determined by onset and/or progression of extracranial tumor activity and not by the number of metastases treated. Patients with Karnofsky Index 100 without extracranial tumoractivity have a median survival of 22,3 months. The 1 and 2 year local control rate of radiosurgically treated BM is 78% and 75% respectively. The overall intracranial tumor control rate is significantly determined by the number of metastases. Conclusions: gamma knife radiosurgery yield high local control rates. Survival after radiosurgery is determined by extracranial tumoractivity. The number of BM determines the overall intracranial tumor control rate but not the survival, probably due to salvage treatment options in patients without untreatable extracranial tumorprogresion.
140 Oral Presentations Abstracts
Diffusion magnetic resonance imaging as an early evaluation of the response of brain metastases treated by stereotactic radiosurgery OS10-3 Chuan-Fu, Huang (1) (1) Chung Shan Medical University Hospital - GammaKnife Center Taichung, Taiwan Objective: Conventionally, treatment response of brain tumors is observed by comparison of sequential magnetic resonance imaging (MRI) or computed axial tomography (CAT), but it is rel- atively slow changing in volume and time consuming. This study utilized diffusion MRI to evalu- ate cellular changes of metastatic brain tumors treated with stereotactic radiosurgery (SRS) to search for a method to detect an earlier therapeutic response. Methods: We conducted a prospec- tive trial in 20 patients with 32 metastatic brain tumors treated by SRS with a 201 - source cobalt in our gamma knife center. Mean dose to tumor margin was 15.2 Gy (range 12-19.6 Gy). All patients received complete diffusion MRI before SRS, at 1 week, 1 month, and 3-month intervals following SRS. An apparent diffusion coefficient (ADC) map was calculated from echoplanar dif- fusion-weighted images and mean ADC values were compared with each other. MRI results and clinical outcome were evaluated at the same intervals. Results: ADC values for water of the metastatic tumors were 0.97 x 10-3 mm2/s ± 0.25 ´10-3. ADC significantly (P=0.009) increased 7 days after SRS continuing through the later one-month and 3-month interval follow- up period (p=0.0001). MRI results at 3-month intervals demonstrated stable or smaller tumor size in all patients except 2, whose tumors had enlarged due to tumor necrosis. Enhanced MRI was difficult to differentiate recurrence from radiation necrosis in those tumors, but ADC favored necrosis due to the high values. One patient with tumor regrew at 15 months after treatment also revealed pretreatment ADC level at same time and rose after retreament. Conclusion: ADC values of brain metastases after SRS kept upward trend it can be used to predict the successful treatment and differentiate radiation necrosis or recurrence.
Gamma knife radiosurgery alone as an alternative treatment for melanoma brain metastasis OS10-4 Xavier, Muracciole (1); Jean, Regis (2) (1) CHU La Timone - Service de Radiotérapie; (2) CHU La Timone - Service de Neurochirurgie Marseille, France PURPOSE: To assess the control rate of melanoma brain metastasis (BM) treated with Gamma- Knife radiosurgery alone (SRS) the factors that predicted best survival using this strategy. PATIENTS AND METHODS: 241 intracranial melanoma metastasis in 106 patients were consecu- tively treated by GK between juanary 1993 and december 2003. Overall survival and brain- metastasis-free survival from the date of first GK were calculated using the Kaplan-Meyer method. Relevant factors affecting survival were considered for univariate analysis, and multivariate analy- sis with classification and regression tree models were performed and compared RPA, SIR and BSBM pronostic classifications. RESULTS: Median age was 56 years (range, 26-82 years). Median Karnofsky index was 90. A total of 65 patients ( 61%) was treated for a single BM in which 18 had no extracranial metastasis (17%), 20 for 2 BM and 21 3 BM. Only 14 patients were free of history of extracranial metastasis. 80 patients presented an active extracranial metastasis at the time of RS. 98 patients were classified in RPA class 2 and , 45 with SIR 6-7 and 78 with BSBM. 141 Oral Presentations Abstracts
The median tumor volume was 1.2 cm3 (range, 0.4-33.5). The median marginal dose and iso- dose were 25 Gy (range, 14-40 Gy) and 50% (range, 40%-70%), respectively. The median fol- low-up was 4 months, 46 patients were still alive 6 months after GK, 25 after 9 months and 14 at 1 year. The 1-year local control (LC) for evaluated patients (54% of entire population) was 66% and 24/118 had recurred. The median distant brain metastasis-free survival and overall survival were 4 and 5 months respectively. Survival rate was 43% at 6 months, and 13% at 1 year. In multivariate analysis, Karnofsky Index > 90, absence of brain stem, central nuclei or cerebellum localisations, isolated and solitary BM, and SIR > 6 were independantly associated with a bet- ter survival rate. According to logistic regression, short term survival (> 6 months) was best pre- dicted by SIR > 6 (p=0.001) and solitary brain metastasis without other visceral metastasis (p=0.03). DISCUSSION : GK surgery alone obtained high local control as neurosurgery approach. Although prolonged survival is rare in this population, GK offered a significant quality of life in most patients with melanoma BM. In our series, BM were a late event in metastatic melanoma with a very poor outcome. Initial RC alone was an effective treatment modality for cortical cere- bral melanoma BM and should be considered in patients with SIR >6. A new pronostic classifi- cation was established with 4 classes taking into account Karnofski index, age and BM location, with a better accuracy (AUC =0.712) than the others classifications.
MENINGIOMAS 1 OS11 Chairmen: Hidefumi, Jokura; Robert, Smee Room Permeke & Rembrandt
Hypofractionated stereotactic radiotherapy for benign meningioma OS11-1 Michael, Dally (1); Louise, Gorman (1); Jeremy, Reuben (1); Robert, Myers (1) (1) The Alfred Hospital - Radiation Oncology Department Melbourne, Australia Aim: To examine the safety and efficacy of hypofractionated stereotactic radiotherapy with refer- ence to one particular scheme in the treatment of benign meningioma. Total dose of between 35 - 40 Gy in 15 fractions over 3 - 3.5 weeks were prescribed to the periphery of the tumour based on traditional hypofractionated radiotherapy as used at the Christie hospital in Manchester. Methods: 40 patients with a total of 41 tumours were treated between May 1997 and May 2004. The median dose prescribed was 37.5 Gy to the 80% isodose. Patients were followed prospectively with annual MRI and clinical assessment with mean and median follow-up of 35.4 and 28.7 months respectively. Results: 11 males and 29 females of median age 55 years received treatment. 16 tumours involving cavernous sinus and/or Meckel's cave and 17 involving the Petro-clinoid area were noted. Twenty-five patients had previously undergone a biopsy or partial resection. Two were treated after recurrence. The remaining 14 were diagnosed on radiological grounds alone. Where histology was available, grade 1 histology was noted for except two with atypical features. Malignant tumours and Hemangiopericytoma were excluded. Clinical follow-up noted no change or improvement in 33 patients. Temporary increase in speech and swallowing disturbance was noted in one patient with radiological evidence of radiation necrosis. A tempo- rary worsening of V2 paraesthesia or diplopia were observed in two patients without associated radiological changes. MRI scans showed no change in 29 patients, a reduction of tumour size in 142 Oral Presentations Abstracts
10. One patient had progression on MRI scan and received further treatment. Conclusion. Early data would suggest conventional hypofractionated radiotherapy schemes for benign CNS disease may be useful in conjunction with stereotactic techniques. Such schemes are attractive in terms of resource allocation and are an alternative to stereotactic radiosurgery where tumour size, posi- tion or cranial nerve tolerance is of concern.
Stereotactic radiosurgery and fractionated stereotactic radiotherapy for meningiomas related to the optic apparatus OS11-2 Leonardo, Frighetto (1); Carlos, Mattozo (2); Alessandra, Gorgulho (3); Michael, Selch (4); Cynthia, Cabatan- Awang (3); Timothy, Solberg (4); Antonio, DeSalles (5) (1) University of California Los Angeles - Neurosurgery; (2) UCLA Medical Center - Neurosurgery; (3) UCLA Medical Center - Department of Neurosurgery; (4) UCLA - Radiation Oncology; (5) UCLA Medical Center - Neurosurgery Los Angeles, United States Objective: To evaluate treatment outcomes of Stereotactic Radiosurgery (SRS) and Fractionated Stereotactic Radiotherapy (SRT) for meningiomas related to the optic apparatus regarding tumor control and optic toxicity. Materials and Methods: This study included 50 patients harboring meningiomas related to the optic apparatus treated at UCLA. There were 37 females (74%) and 13 males (26%). SRS was the treatment of choice in 15 (30%) and SRT in 35 (70%) patients. The median follow-up was 72 (6-141) and 44 (7-89) months respectively. The median dose for SRS was 1600 cGy (1200-2000) prescribed to a median isodose line of 50%. A median dose of 4860 cGy (2380-5040) prescribed to a median isodose line of 90%, was administered for SRT patients. Tumors were located with a maximal distance of 1.2 mm from the optic apparatus for patients treated with SRT and 2.5 mm for patients treated with SRS. Results: Tumor control was 93.3% for SRS and 97.1% for SRT. One SRS patient (6.6%) recurred at 57 months of follow-up requiring microsurgery. A patient treated with SRT (2.8%) presented with recurrence at 38 months and was treated with SRS. Side effects for SRS were limited to three patients (20%), one presenting with facial hypoesthesia and two with decrease in visual acuity. A patient treated with SRS for a cav- ernous sinus tumor presented with a stroke related to carotid artery stenosis by the tumor. Two patients submitted to SRT also presented with facial hypoesthesia and one complained of subjec- tive worsening of a previously existing diplopia. The overall rate of side effects for SRT was 8.5%. Visual improvement occurred in four patients (11.4%) in the SRT group. Conclusions: SRS and SRT were both effective in providing tumor control. An absence of visual acuity complications and the capability of visual improvement were observed when SRT was used for meningiomas related to the optic structures.
143 Oral Presentations Abstracts
Improvement in vision and other cranial neuropathies after stereotactic radiotherapy for the treatment of skull base meningiomas OS11-3 Tracy, McElveen (1); Kathleen, Settle (1); Beverly, Downes (2); Maria, Werner-Wasik (1); Wally, Curran (1); David, Andrews (3) (1) Thomas Jefferson University - Radiation Oncology/Neurosurgery; (2) Jefferson Hospital for Neuroscience - Department of Neurosurgery Philadelphia, USA Purpose: To evaluate the outcome of cranial neuropathies in patients treated with stereotactic radiosurgery for meningiomas in the anterior skull base. Patients and Methods: Two hundred and thirty nine patients were treated with fractionated stereotactic radiosurgery for meningiomas at the Jefferson Hospital for Neurosciences between 1994 and 2002. Of these patients, 117 had tumors located in the anterior skull base. All patients were immobilized using a GTC relocatable frame and underwent CT-MRI fusion for treatment planning. The mean target volume was 11.7cc (range 0.7 - 45.1cc). Patients were treated with a dedicated 6 MV linear accelerator using circu- lar collimators directed in noncoplanar arcs with an average of 2.6 isocenters (range 1 - 7). Dose was delivered in 1.8 Gy fractions to a median cumulative dose of 54.0 Gy (range, 9.0 - 56.0 Gy), during a 5-week period. The median follow-up time was 32 months (range 7 – 96 months). Patients were examined and imaged with MRI during the first 3 months after receiving SRT and every 6 months thereafter. Baseline cranial neuropathies were evaluated clinically and character- ized as stable, improved, resolved or progressive in the follow-up period. Pre- and post-radiother- apy serial radiographic evaluations, including MRI scans were compared to establish objective tumor response and local control. Results: Fifty-two patients had deficits in visual fields or acuity that were associated with their tumors and potentially reversible with treatment. At the latest fol- low up, eleven patients (21%) had a stable visual examination as measured by refraction, near card evaluation, confrontation or automated perimetry. Twenty-seven patients (52%) had docu- mented improvement in vision, and three patients (6%) had complete resolution of all visual deficits. The median time to visual improvement or resolution was 52 weeks by hazard plot. Seven patients (13%) experienced progressive vision loss after treatment, five of which corre- sponded to radiographic tumor progression. Six patients were lost to follow-up and visual out- comes are therefore unknown. Fifty-nine patients had cranial neuropathies, which did not involve the optic nerve. Of these, 18 patients (31%) had stable symptoms, 15 patients (25%) had improvement in their deficits and 11 patients (19%) had complete resolution of all cranial neu- ropathies. These results demonstrate a 68% chance of cranial nerve improvement by cumulative hazard plot. Nine patients (15%) had progressive cranial nerve findings, five of which were attrib- uted to progressive disease. Complete serial MRI evaluation was available on 107 patients and revealed stable disease in 88 patients (82%). Twelve patients (11%) showed tumor regression occurring at a median time of 52 weeks (range 12 - 261). Seven patients (6%) had radiographic progression of the treated lesion. Local control was 94% in our series. Conclusion: This report includes one of the largest series of anterior skull based meningiomas and confirms that fraction- ated stereotactic radiotherapy is a safe and effective treatment modality. Patients with tumor-asso- ciated cranial neuropathies have a high likelihood of improvement in their symptoms within the first year of treatment. Stereotactic radiotherapy provides excellent tumor control and offers preservation or improvement of function to patients with tumors in these challenging locations. 144 Oral Presentations Abstracts
Optic nerve sheath meningiomas. The role for stereotactic radiotherapy OS11-4 Robert Ian, Smee (1); Margaret, Schneider (1); Janet, Williams (1) (1) University of New South Wales - Prince of Wales Hospital - Department of Radiation Oncology Randwick, Australia PURPOSE: Primary orbital meningiomas are rare, the usual site of origin being the optic nerve sheath. These represent 1-2% of all meningiomas. This is a review of a single centre’s experience. MATERIALS AND METHODS: Between 1990 and February 2004 27 patients were referred and 17 patients were treated by radiotherapy (mean age 51 years). This retrospective study evaluated 17 patients – 18 tumours (1 patient with NF2 had bilateral optic nerve tumours). Nine patients were treated with newly diagnosed lesions, and 8 recurrent after prior treatment including radiothera- py for 2 patients. The median duration of symptoms to onset was 2 months. Treatment consist- ed of SRS (median dose 20Gy) where vision was not a consideration, and fractionated SRT (medi- an dose 5040Gy in 28fx) for vision preservation. RESULTS: Median follow up is 46.8 months. Each recurrence after SRT occurred in 1 patient leading to progressive disease and blindness, this new lesion was treated with SRS, the tumour controlled with subsequently some vision improve- ment. Only one other patient had progressive disease, thus for an ultimate local of 94%. For frac- tionated patients only the above patient had worse vision after treatment. CONCLUSION: Radiotherapy provides high local control, utilising fractionated treatment provided it covers the full length of the nerve, is necessary to have the option of preserving vision.
PHYSICS – GENERAL OS12 Chairmen: Frank, Bova; Stephan G., Scheib Room Willumsen
Stereotactic IMRS for intracranial tumours OS12-1 Robert Ian, Smee (1); Margaret, Schneider (1) (1) University of New South Wales - Prince of Wales Hospital - Department of Radiation Oncology Randwick, Australia PURPOSE: There is a size limit to the lesions that can be treated by SRS. To investigate whether using a MMLC will enable larger lesions to be treated in a single fraction. MATERIALS AND METH- ODS: Intensity Modulated Radiotherapy enables the definition of dose limiting structures, creat- ing a safer dose hierarchy relative to the tumour being treated. Sharper conformity provided by MMLC defines tumour borders, and thus can be used to exclude normal tissue. These two con- cepts can be wedded to provide single dose treatment for lesions too large for FRS. A rigid QA system is required to assure accuracy and precision. Over the last 3 years of 290 patients having SRS, this was delivered as IMRS in 32. The conditions treated were: meningioma 25, pituitary 3, AVM 2, Others 2 with a median dose of 14Gy. Median diameter was 3.5cm and the volume 15.4ccm. The only extra step was the QA procedure developing the fluence maps, with median treatment time of 25 minutes for 4000 monitor units. This is given as multiple fixed fields. The procedure itself was tolerated well with no added untoward side effects other than increased like- lihood of hair loss. All the meningiomas were controlled with no cranial nerve or brain stem relat- ed deficit. One of the 2 AVMs treated was obliterated after 2 years follow up. CONCLUSION: Large intracranial tumours may be able to be treated as a single fraction, to give local control and low morbidity, using IMRS. 145 Oral Presentations Abstracts
Monte Carlo simulation for gamma knife radiosurgery using the Grid OS12-2 Vasu, Ganesan (1); Rami, Mehrem (2); John, Fenner (2); Lee, Walton (1) (1) University of Sheffield - Department of Medical Physics and Clinical Engineering; (2) Royal Hallamshire Hospital - National Centre For Stereotactic Radiosurgery Sheffield, United Kingdom Objective: To validate the viability of the GRID resource for the Monte Carlo simulation of gamma knife radiosurgery plans. Introduction: Grid Enabled Medical Simulation Services (GEMSS) was a project developed by the European Union to validate the application of a Grid of powerful com- puters for the solution of complex medical computational problems. The GRID contains about 70 processors placed in Austria and Germany for the GEMMS applications. As one such application, Sheffield Teaching Hospitals in collaboration with Sheffield University tested the grid for the sim- ulation of gamma knife Dosimetry using Monte Carlo techniques. Materials and Methods: Leksell Gamma-Plan (LGP) the commercially available system for calculating the treatment plans gives a dose distribution with an assumption of a homogeneous medium using a simplistic algorithm. Monte Carlo techniques provide a more robust solution and will ultimately enable the incorpora- tion of in-homogeneity corrections (although for the purposes of this work a homogeneous medi- um is assumed presently). A Monte Carlo code called RAPT (Radiotherapy Application for Parallel Technology) code was used to simulate the beams of each of the 4 collimator sizes 4,8,14 and 18 mm of the Gamma knife. The dose distribution of a single collimator helmet (201 beams) pro- duced by a Leksell Gamma plan was compared with the Monte Carlo RAPT produced ones. Software was developed using MATLAB to simulate the patient’s head from the skull radii meas- ured using the bubble-head. This software enabled actual plans including single isocentre shots, multiple isocentric treatment plans, plans with combination of several collimator helmets and plans with plugging patterns. A Graphical User Interface (GUI) was developed using MATLAB to compare the treatment plans made by RAPT and LGP. The GUI gives a facility of overlaying and correlating the isodoses patterns produced by RAPT and LGP in all the three planes (Axial, coro- nal and sagittal). Also the treatment times were calculated and compared with the LGP treatment times. A study was made to optimise the no of photons required for the simulation. About 2-3 million photons per beam were used for the simulation. Results and Discussion: The GUI gives an excellent correlation of the isodoses produced by RAPT and LGP. A Monte Carlo simulation, which takes several hours with a single processor, was reduced using the GRID to less than an hour. It was found that 3 million photons will be required to simulate the 201 beams. And when some sources were made plugged, the number of photons was increased to compensate the flu- ence. About hundred actual radiosurgery treatment plans were compared with the RAPT pro- duced plans and found to be in very good agreement.
Artificial Droplets improves radiation dosimetry of IMRT OS12-3 Kevin, Khadivi (1); Robert, Comiskey (2); Timothy, Klapproth (3); Craig, Hansen (3) (1) Mercy Medical Center - Radiation Oncology; (2) Radionics, a division of Tyco HealthCar - Engineering; (3) Mercy Medical Center - Radiation Oncology Springfield, USA In an inverse-planned IMRT the judicious use of dose constraints in a “fake structure” minimizes dose to a sensitive structure. However, the shielding effect of the fake structures could adversely 146 Oral Presentations Abstracts
influence the dose coverage of the target. Artificial Droplet is a new technique that improves dosimetry of IMRT. XKnife TM RT was used to test phantom and clinical cases in Linac-based stereotactic radiation therapy planning. Instead of using a solid structure as a fake, the treatment planner would use a mesh structure, i.e., artificial droplets, with appropriate dose constraints. This approach provides shielding of the sensitive structure, e.g., cord, parotids, while permitting pencil beams to penetrate through the “droplets” and reach parts of the planning target volume that would have seen considerably less primary beam radiation. Further, the different sizes of the droplets may be spread at different distances to various drawn structures to promote a relocation of undesired radiation hot spots. The influence of pattern (i.e., degree of divergence of the mesh lines), size, and population density of the droplets have been studied. Moreover, the dosimetric response of different algorithm platforms to artificial droplets will be presented. The results of phantom studies and clinical cases demonstrating the favorable dosimetric influence of the artifi- cial droplets in complex head and neck IMRT will be presented.
Standardization for CyberKnife Beam Dosimetry OS12-4 Hidetoshi, Saitoh (1); Toru, Kawachi (2); Mitsuhiro, Inoue (3); Atsushi, Myojyoyama (4); Tatsuya, Fujisaki (5); Shinji, Abe (5); Kimiaki, Saito (6) (1) Tokyo Metropolitan University of Health Sciences - Graduate School of Health Sciences; (2) Tokyo Metropolitan University - Graduate School of Health Sciences; (3) Midori Kai Neurosurgery Hospital - Yokohama CyberKnife Center; (4) Tokyo Metropolitan University - Graduate School of Health Sciences; (5) Ibaraki Prefectural University of Health Sciences - Department of Radiological Sciences; (6) Japan Atomic Energy Research Institute - Health Physics Tokyo, Japan Purpose: In Japan, the number of the CyberKnife systems is increasing significantly for several years, and extracranial cancer might be a target before long. The CyberKnife system has unique treatment head structure and beam collimating system. Therefore the global standard dosimetry protocols have not been applied. To standardize dosimetry protocol, standard conditions of dosimetry, beam quality index and beam quality conversion factors were proposed. A summary of standard dosimetry protocol for CyberKnife beam in Japan will be reported. Methods and Materials: To obtain standard and variance, depth dose distributions of CyberKnives were inves- tigated. Then energy spectra of x-ray beams which agreed with the actual depth dose distribu- tions were simulated with conscientious geometry using OMEGA BEAMnrc code system. Furthermore, mean restricted mass stopping power and mass absorption coefficient for air, water and several wall materials were computed for CyberKnife beam. As a result, the relation between beam quality factor for several ionization chamber and TPR20,10 as beam quality index were determined. Results: In spite of absence of beam flattening filter causes softer photon energy spectra and smaller field than ordinary Linacs, the beam quality conversion factors were approx- imately similar as ordinary 6 MV Linacs. Field by 6 cm collimator was recommended as the refer- ence field because flat range of off-axis ratio was narrow.
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ORAL SESSIONS 11h30 - 12h30
BRAIN METASTASES 2 OS13 Chairmen: Masaaki, Yamamoto; Minesh, Mehta Room Nation
Hypofractionated stereotactic radiotherapy for brain metastases not amenable to radiosurgery OS13-1 Antje, Ernst-Stecken (1); Ulrike, Lambrecht (1); Oliver, Ganslandt (1); Rudolf, Fahlbusch (1); Rolf, Sauer (1); Gerhard, Grabenbauer (1) (1) Novalis Shaped Beam Surgery Center, University Hospital of Erlangen, Germany - Radiation Oncology Erlangen, Germany Purpose/Objective: Primary therapy for brain metastases (mets.) is surgical resection followed by whole brain radiotherapy (WBRT) or radiosurgery (RS) w/o WBRT. Nevertheless, in case of mets. located in eloquent regions, high volume, number >2, irregular contrast enhancement, these therapies may either not be practicable or not promising good results. This study evaluated radi- ological/clinical side effects and response to hypofractionated stereotactic radiotherapy (hfSRT) for mets. not amenable to surgery or RS. Materials and methods: From 1/2003 to 2/2005, 51 pts. with 72 mets. received either 5x6 Gy hfSRT plus WBRT (n=44 mets.) or 5x7 Gy without WBRT (n=28 mets.), prescribed to the 90%-isodose. Patient positioning and isocenter verification was done by ExacTrac at the Novalis System (BrainLAB, Heimstetten, Germany). Maximum number of mets. was 4 in 2 pts.. 16 mets. were irradiated by static beam, all others by dynamic conformal arc treatment. Results: Median FU is 7.2 mos..RTOG-quality assurance criteria were in all cases fullfilled with a median homogeneity, conformity index of 1.12 and 1.22 and a median coverage of 99%, respectively. Cause of death was brain failure in 27%, extracranial failure in 18%. 55% are alive or died due to other causes than tumor until last follow up. Brain-specific-survival/over- all-survival at median FU are 71% and 68%, respectively. The only significant parameters influ- encing both kinds of survival were gross tumor volume (GTV) and planning target volume (PTV) with a positive influence of GTV < 6 cc and PTV < 13 cc. Response of metas-tases was as fol- lows: no change 12.5%, partial response 18.1%, complete response 66.7% and progressive dis- ease 2.8%. Side effects as necrosis, increase in edema and time of steroid medication after hfSRT were influenced by the volume of normal brain treated > 4 Gy / fx. Conclusions: HfSRT is an effective treatment for large volume and ring enhancing metastases regardless their histology. Significant factors influencing survival are GTV and PTV. Side effects significantly correlate with the irradiated volume of normal brain tissue above 4 Gy per fraction.
148 Oral Presentations Abstracts
Response rate and biologically effective dose correlation in stereotactic irradiation of adenocarcinoma brain metastasis OS13-2 Filippo, Grillo-Ruggieri (1); Paolo, Cavazzani (2); Massimo, Cardinali (3); Giovanna, Mantello (4); Stefania, Maggi (5) (1) Ospedali Galliera - Radioterapia; (2) Ospedali Galliera, Genova, Italy - Neurochirurgia; (3) Ospedali Riuniti, Ancona, Italy - Radioterapia; (4) Ospedali Riuniti, Ancona, Italy - Radioterapia; (5) Ospedali Riuniti, Ancona, Italy - Fisica Sanitaria Genova, Italy Purpose. To compare Biologically Effective Dose (BED) and response rate in stereotactically irradi- ated adenocarcinoma brain metastasis. Material and Methods. 55 patients, 36 male, 19 female, 64 years (44-79), ECOG P.S. >= 60, with 67 MRI staged adenocarcinoma brain metastasis were treated using the same treatment planning system (Plato), 6 MV beam energy from Varian 2100 C/D linac, conical tertiary collimation with 10 mm (4 lesions), 15 mm (7), 20 mm (9), 22.5 mm (2), 25 mm (15), 27.5 mm (3), 30 mm (20), 35 mm (6) and 40 mm (1) diameters at isocenter, fixed or relocatable Leksell type frame, 4 to 6 arcs and prescribed isocenter dose with at least 90% isodose covering the PTV. The only main difference has been single dose (34 pts) versus fraction- ated dose (21 pts) stereotactic irradiation. Results. Total Doses from 16 to 25 Gy, transformed into Linear-Quadratic Model BED ( with 10 as alfa/beta ratio value for tumor), resulted into BED dose from 22,5 to 87,5 Gy10. In 61 lesions, evaluable with CE CT at three months follow up, BED <60 Gy10 (fractionated) resulted into 1 CR, 7 PR, 8 SD, 1 PD, while, after 60 Gy10 and > 70 Gy10 single fractions, 6 CR, 12 PR, 2 SD, 2 PD and 9 CR, 9 PR, 3 SD, 1 PD were obtained, respective- ly (P = 0.014). Conclusions. Pretreatment BED calculation could be used to increase the physical dose of fractionated stereotactic treatments to BED equivalent to single fractions, in order to prospectively achieve the same response rate, using a non invasive relocatable frame with better patient comfort.
Gamma knife surgery for large metastatic brain tumors to avoid developing to severe peritumoral edema OS13-3 Motohiro, Hayashi (1); Taku, Ochiai (1); Masahiro, Izawa (1); Mikhail, Chernov (1); Koutaro, Nakaya (1); Tomokatsu, Hori (1) (1) Tokyo Women's Medical University - Department of Neurosurgery Tokyo, Japan Rationale: In Gamma knife surgery (GKS), metstatic brain tumor is the most common indication in Japan. Majority of patients with metastasis maintained highly QOL even though a few days hospitalization. However, not few patients with large metastatic brain tumor experienced postop- erative complication, severe radiation injury, after GKS based on an inadequate dose planning. To the purpose of keeping patients’ QOL, we prefer not to perform over-irradiation to the surround normal brain tissue. Methods: We treated 542 cases with brain metastasis with GKS using model C-APS for these 2 years (since Jan 2003). We did use 16-24Gy, which was determined on tumor volume, as a prescription dose at 50% isodose. Our treatment strategy was tumor covering with highly conformity and homogeneity, in addition no putting each isocenter on the outer side of tumor edge. We calculated energy (mJ), unit energy (mJ/cc), and average dose (Gy) in both tumor and surround brain tissue for each patient. Results :Local tumor control rate was observed in 97.2% (527/542). 8.9% (48/542) of the patients experienced radiation injury, and 1.1% (6/542) 149 Oral Presentations Abstracts
of them developed radiation necrosis. On the other hand, prior to this methodology, radiation injury was observed in 16.7% in our institute on between Jan and Dec in 2002. The most impor- tant matter is that unit energy of surround brain tissue should be decreased as much as possible (< 7.0mJ/cc). Conclusions: We supposed the optimal dose planning for large metastatic tumors and evaluated clinical results taking account for patients’ QOL. Radiosurgery is not radiation ther- apy, so that we should pay attention to the location of each isocenter keeping not beyond to the surround normal barin tissue.
Gamma knife surgery for metastatic brain tumors from lung cancer OS13-4 Toru, Serizawa (1); Yoshinori, Higuchi (2); Shinji, Matsuda (3); Junichi, Ono (4); Makoto, Sato (5); Toshihiko, Iuchi (6); Osamu, Nagano (7); Naokatsu, Saeki (8) (1) Chiba Cardiovascular Center - Department of Neurosurgery; (2) Chiba Cardiovascular Center - Department of Neurosurgery; (3) Chiba Cardiovascular Center - Department of Neurology; (4) Chiba Cardiovascular Center - Department of Neurosurgery; (5) Chiba Cardiovasucular Center - Department of Radiology; (6) Chiba Cancer Center - Division of Neurological Surgery; (7) Graduate School of Medicine, Chiba University - Department of Neurological Surgery; (8) Graduate School of Medicine, Chiba University - Department of Neurological Surgery Chiba, Japan Purpose: This study was deigned to evaluate results of a local treatment protocol using gamma knife surgery (GKS) for brain metastases from lung cancer. Materials and Methods: Among 659 cases with brain metastases from lung cancer treated with GKS at Chiba Cardiovascular Center from 1998 through 2004, 608 consecutive patients who satisfied the following 4 criteria were analyzed: 1) no prior whole brain radiation therapy (WBRT), 2) a maximum of 5 tumors with a diameter of >=20 mm; 3) no cerebral dissemination (<=25); 4) no large (>35 mm) tumors. All lesions were treated with GKS without upfront WBRT. New distant lesions, detected with fol- low-up MRI every two to three months, were appropriately re-treated with GKS. Overall survival (OS), neurological survival (NS), qualitative survival (QS) and new lesion-free survival (NLFS) were calculated and the prognostic values of the covariates were obtained. Results: In total, 1204 sep- arate sessions were required to treat 6427 lesions. Median OS period was 8.9 months. In multi- variate analysis, significant prognostic factors for OS were systemic control (risk factor: uncon- trolled), initial KPS score (<70) and gender (male). NS and QS at 1 year were 88.6% and 81.3%, respectively. The only significant poor prognostic factor for NS was carcinomatous meningitis (CM). Lack of systemic control, poor KPS and CM were significant factors influencing QS. NLFS at 6 months and 1 year were 72.5% and 47.4%. Three hundred seventy-six (62%) patients did not require salvage treatment. WBRT was employed in 8 (1.3%) for cerebral dissemination. Patients with numerous (>10) tumors had a significantly poorer prognosis than those with <=10. Conclusion: Our local protocol, aggressively applying GKS, provides excellent results in selected patients with <=10 brain lesions and no CM.
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MENINGIOMAS 2 OS14 Chairmen: Hidefumi, Jokura; Robert, Smee Room Permeke & Rembrandt
The role of radiosurgery in the management of petroclival meningiomas OS14-1 Dong Gyu, Kim (1); Chul-Kee, Park (1); Hyun-Tai, Chung (1); Sun Ha, Paek (1); Hee-Won, Jung (1) (1) Seoul National University Hospital - Department of Neurosurgery Seoul, Republic of Korea INTRODUCTION. Experience with the management of petroclival meningiomas was analyzed to evaluate the optimal role of radiosurgery. METHODS. The records of 61 patients with petroclival meningioma were reviewed. Their mean age was 46.2 years. The population was divided into a surgery group (n = 49) and a radiosurgery group (n = 12). In the surgery group, the mean vol- ume of the tumor was 46.9cc (range 5.2-235.8). The tumor was completely resected in 10 patients. Eleven of the 39 patients with incomplete resections sequentially underwent adjuvant radiation therapy or radiosurgery. The median follow-up period was 86 months (range 48–210). The radiosurgery group was treated with gamma knife surgery. The mean volume of the tumor was 5.46cc (range 2.1-17.2) and the median follow-up period was 52 months (range 48–71). Management outcomes were evaluated with respect to tumor control rate, neurological deficit and functional status. RESULTS. In the surgical group, 11 patients (22.4%) eventually showed tumor progression. However, there was only one recurrence if adjuvant therapy was used after incomplete removal. The incidence of favorable outcomes for cranial neuropathies and function- al status were better in the incomplete resection group (69.2% and 76.9%) than for patients in the complete resection group (20% and 30%) significantly (p=0.032 and p-0,049). Besides, the disease was stable in all patients of radiosurgery group during the follow-up period, with func- tional status and cranial nerve function perfectly preserved in these patients. CONCLUSIONS. Because the growth rate of petroclival meningioma is low and good functional status can be guarantied, incomplete resection of large tumor should be considered as an acceptable treatment option. And adjuvant radiosurgery is useful in the control of residual tumors. Radiosurgery may also be appropriate as the primary treatment in small tumors. The selection of treatment should take into consideration the quality of life of the patients, as well as tumor control.
Gamma knife radiosurgery for cavernous sinus meningiomas - ten year follow-up period OS14-2 Martina, Stippler (1); John, Lee (2); John C, Flickinger (3); Douglas, Kondziolka (3); L. Dade, Lunsford (4) (1) University of Pittsburgh Medical Center - Neurological Surgery; (2) Hospital of the University of Pennsylvania - Neurosurgery; (3) University of Pittsburgh Medical Center - Department of Neurological Surgery; (4) University of Pittsburgh Medical Center - Image Guided Neurosurgery Pittsburgh, USA Introduction: The long term results after gamma knife radiosurgery for benign cavernous sinus meningiomas remain controversial. The authors retrospectively reviewed their experience with those patients who had a minimum of ten years possible follow-up. Methods: Eighty-one patients with cavernous sinus meningiomas were treated at the University of Pittsburgh from 1987 to 1995. Three patients were lost to follow-up. 49 patients (62%) had a prior craniotomy. Results: 151 Oral Presentations Abstracts
The median age for group at time of radiosurgery was 56 years (range 12-87 years). Fifty-nine patients (73%) were female. The median tumor volume was 6.5 cm3, and the median marginal dose was 15Gy. The median neuroimaging follow-up period for these patients was 79 months (range 2-169 months). Four patients have demonstrated increases in the size of their tumor, resulting in an overall actuarial tumor control rate of 96 ± 2.6% at five years and 85 ± 8.1% at ten years. Three of the four imaging-documented treatment failures occurred in patients who had prior craniotomies. The ten year actuarial tumor control rate in patients who have not had prior craniotomy is 96 ± 4.1%. Conclusion: Gamma knife radiosurgery is an effective procedure for patients with cavernous sinus meningiomas. The long-term results demonstrate a favorable con- trol rate with minimal complications.
Gamma knife radiosurgery of skull base meningiomas OS14-3 Roman, Liscak (1); Aurelia, Kollova (2); Vilibald, Vladyka (3); Gabriela, Simonova (1); Josef, Novotny Jr. (4) (1) Hospital Na Homolce - Stereotactic Neurosurgery Department; (2) Royal Hallamshire Hospital - National Centre For Stereotactic Radiosurgery; (3) Na Homolce Hospital - Stereotactic and Radiation Neurosurgery; (4) Hospital Na Homolce - Medical Physics Department Prague, Czech Republic Meningiomas are the most frequently treated benign tumors by gamma knife radiosurgery and the majority of them are located on the skull base. Between 1992 and 1999, 197 skull base- located meningiomas in 192 patients were treated by gamma knife in Prague. Contact with the chiasma or optic tract was not regarded as a contraindication for gamma knife radiosurgery and this contact was observed in 32% of the skull base meningiomas treated. 176 patients were monitored for a median of 36 months, of whom 73% showed a decrease in tumor volume, no change was observed in 25% and continued growth was observed in 2%. Neurodeficit improved in 63% of patients, temporary morbidity occurred in 11% and persistent morbidity remained in 4.5%. Radiosurgery induced edema in 11%. Significantly lower edema occurrence was observed after radiosurgery in patients with no history of edema prior to radiosurgery, where the tumor was located in the posterior skull base and where the dosage to the tumor margin was lower than or equal to 14 Gy. Radiosurgery of skull base meningiomas has been proven to be safe and efficient. We consider gamma knife treatment for skull base meningiomas to be the method of choice whenever tumors are within the volume limits and there is no need for an urgent decom- pressive effect from the open operation.
Linac radiosurgery for the management of cavernous sinus meningiomas OS14-4 Salvador, Somaza (1) (1) La Floresta Medical Institute - Stereotactic Radiosurgery Unit Miami, USA Introduction: The authors retrospectively reviewed their 5-year experience to evaluate the effica- cy of stereotactic Linac radiosurgery in patients with cavenous sinus meningiomas. Methods: Between July 2000 and September 2004, 63 patients with meningiomas were treated with linac radiosurgery at La Floresta Medical Institute. Twelve patients had cavernous sinus meningiomas. The median age for the subgroup was 46.5 y.o. (range 21 to 67 years). There were 9 women and 3 men. Two patients underwent partial surgical removal procedures. A mean radiation dose of 152 Oral Presentations Abstracts
14.22 Gy was delivered to the tumor margin. The median follow-up was 33.2 months (range 8 to 57 months). Results:Tumor control was achieved in all of the patients. Treatment-related com- plications included only one case with moderate facial hypoesthesia in V1 distribution. No other complications were noted. Improvement of existing cranial neuropathies was observed in 4 patients (25%). There is no mortality as a consequence of the treatment. Conclusions: Linac radio- surgery is a safe and effective procedure for patients with cavernous sinus meningiomas offering an excellent control for residual or recurrent tumors as well as for previously non-treated tumors.
PHYSICS - LEAKAGE OS15 Chairmen: Stephan G, Scheib; Stéphane, Simon Room Willumsen
Measurement of the exit dose to the neck from intracranial stereotactic radiotherapy, using the M3 mini MLC OS15-1 Dror, Alezra (1); Janna, Menhel (1); Rafael, Pfeffer (1); Roberto, Spiegelmann (2) (1) Sheba Medical Center - Department of Oncology; (2) Sheba Medical Center - Department of Neurosurgery Ramat Gan, Israel Introduction: The purpose of this study was to measure the exit dose to the neck from intracra- nial stereotactic radiation delivered using the BrainLab M3 mini MLC. The dose to the surface of the larynx was measured in-vivo in patients treated with either single fraction radiosurgery (SRS) or fractionated stereotactic radiotherapy (FSR). 4 to 5 conformal arcs were used to deliver SRS doses ranging from 13 Gy up to 20 Gy, FSR total doses were 50.4 Gy delivered in 28 fractions of 1.8 Gy. An ionization chamber was used to record the dose to the larynx. This dose was meas- ured above the larynx in order to represent the maximum dose to the thyroid gland which is the organ most likely to develop long term toxicity from the radiation. Additional studies were carried out with a phantom. Results: A significant difference was found in the exit dose to the larynx. This was more dependent on field size (jaws positions) and less on other parameters such as isocenter position and arc arrangement. The exit dose to the larynx is increasing significantly when the field size is 6x6 cm or larger. The dose to the larynx can change from 0.3% of the total dose in smaller fields to 2.5% in field’s larger then 6x6 cm. That relationship can be described by a simple function that estimates the exit dose to the neck. Conclusion: When planning single frac- tion stereotactic radiosurgery in which field sizes are usually below 5 x 5 cm the exit dose to the larynx and thyroid is usually below 0.3%, On the other hand when planning stereotactic fraction- ated irradiation where the field size is often significantly greater the use of a sagittal arcs which may exit through the neck and thyroid gland should be avoided in order to minimize the risk of hypothyroidism and radiation-induced malignancy, particularly in younger patients.
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Dosimetry of thyroid, parotid and ovarian glands in patients undergoing Gammaknife radiosurgery OS15-2 Mahmoud, Allahverdi (1); Aliakbar, Sharafi (2); Alireza, Nikoofar (3); Hadi, Hassanzadeh (4) (1) Tehran university of medical sciences - Cancer institute,radiotherapy physics; (2) Iran Medical Science Of University, Ali Asghar Hospital - Iran Gamma Knife Center; (3) Iran university of medical sciences - Medical Physics; (4) Iran university of medical sciences - Medical Physics Tehran, Iran The purpose of this study was to indentify the dose delivery to the parotid,ovaries and thyroid glands during the Gammaknife radiosurgery procedure. A three-dimensional,anthropomorphic phantom was developed using natural human bone material,paraffin and sodium chloride as the equivalant tissue.The Phantom was composed of a body,head and neck and hip.In the natural places of thyroid ,parotid (bilatreal sides) and the ovaries(midline ) some cavities were made to place the thermoluminescence dosimeters(TLDs). Three TLDs were inserted in a batch (probe) with 1cm space between the TLDs and each batch was instered into a single cavity. The final depth of TLDs was 3 cm from the surface for parotid and thyroid and was 15 cm for the ovarian glands.Similar probes were placed superficially on the phantom. The phantom was gamma irra- diated using Leksell model C Gammaknife unit .Subsequently ,the same probes were placed superficially over thyroid ,parotid and ovaries in 12 patients who were undergoing radiosurgery treatment for brain tumors.The mean dosage for treating these patients was 15.8 Gy in the 50% isodose curve. There was no signficant difference bwtween the superficial and deep probes in the phantom studies.The mean delivery dose to the parotid ,thyroid and ovaries in human subjects was 15.3 ± 8.9cGy ,9.2± 4.4 cGy and 0.6 ±0.3 cGy ,respectively. The data can be used in deci- sion making for special clinical situations such as treating pregnant patients who need radio- surgery for eradication of brain tumors.
In vivo estimation of extracranial doses in stereotactic radiosurgery with the gamma knife and Novalis systems OS15-3 Thierry, Gevaert (1); Dirk, Verellen (2); Stéphane, Simon (3); Françoise, Desmedt (1); Bob, Schaeken (4) (1) Hôpital Erasme - Centre Gamme Knife; (2) AZ VUB - Physique; (3) Institut J. Bordet - Physique; (4) AZ Middelheim - Physique Brussels, Belgium OBJECTIVE: The purpose of this work is to investigate the extracranial doses in vivo during intracranial treatments comparing the gamma knife-system with the Novalis-system for the same pathologies. The analysis is limited to single fraction stereotactic radiosurgeries. METHODS: Measurements were performed with TL dosimeters positioned on the lateral canthus, thyroid, breasts and gonads to obtain the dose received to these anatomical regions. Based on these observations, an estimate of the risk for cancer induction and detriment will be proposed. The measured doses were normalised to 24 Gy, and the influence of target maximum dose, reference isodose volume, equivalent treatment time (which is related to the activity of the cobalt-60 sources for the gamma knife) and distance on extracranial doses are analysed. RESULTS: The aver- age extracranial dose with a normalised prescription dose of 24 Gy is comparable for both machines.Gamma knife: For the lateral canthus, thyroid, breast and gonads the median doses were 435, 103, 47, and 5.9 mGy, respectively. Novalis: For the lateral canthus, thyroid, breast and gonads the median doses were 233, 83, 45 and 2.8 mGy, respectively. For the gamma knife- 154 Oral Presentations Abstracts
system as well as the Novalis-system no correlation could be found between maximum dose, ref- erence isodose volume and extracranial doses. On the other hand for the gamma knife-system the equivalent treatment time and distance have a significant influence on doses received on extracranial sites. For the Novalis-system only the distance and the geographical placement of the arcs will influence the extracranial dose. CONCLUSIONS: Doses to extracranial sites are small, ranging from 1,4 % of the prescribed dose (24 Gy) for the lateral canthus to 0,02 % for the gonads for the gamma knife and in the range of 0,97 % of the prescribed dose (24 Gy) for the lateral canthus, to 0,01 % for the gonads for the Novalis. According ICRP-60, the risk for cancer induction after a radiosurgical treatment is estimated to about 0,2 % for both the gamma knife and Novalis systems; the risk for detriment is estimated at 0,3 % for both systems. Although these risks are very small, they must be kept to a minimum value for long life expectancy patients, by choosing the appropriate treatment strategy.
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Wednesday 14/09/05
PLENARY SESSION 8h45 – 10h00
PS3 Room Nation DATA BLITZ UPDATE 3 Brain Metastases PS3-1 Minesh, Mehta
DATA BLITZ UPDATE 4 Physics PS3-2 Frank, Bova
COMPARATIVE TECHNOLOGIES Chairmen: Minesh, Mehta; Frank, Bova
Patterns of practice in a radiosurgery center equipped with both gamma knife and Linear Accelerator PS3-3 Robin, Stern (1); Julian, Perks (1); Allan, Chen (1) (1) U.C. Davis Cancer Center - Radiation Oncology Sacramento, USA Purpose: Due to the fundamental differences in treatment delivery, Linear-accelerator-based radio- surgery can be complementary to gamma knife for intracranial lesions. We reviewed the effect of adding gamma knife to an existing Linac-based radiosurgery practice and analyzed case selec- tions for the two modalities. Material and Methods: UC Davis Medical Center installed a Leksell gamma knife Model C in October 2003 to supplement an established Linac-based radiosurgery program. Radiosurgery indications for the 15 months before and after installation were com- pared. Results: Radiosurgery cases expanded by two-fold from sixty-eight patients before gamma knife installation to 139 after, with 106 treated by gamma knife and 33 by Linac. Besides a major increase for trigeminal neuralgia and a general growth for acoustic neuroma, meningioma and brain metastases, case numbers for glioma and AVM remained stable. Considering case selec- tions for Linac, glioma decreased from 28% to 18%, while meningioma and metastases increased from 9% to 24% and 38% to 46%, respectively. The Linac patients receiving fractionated treat- ment also increased from 37% to 61%. Conclusions: While the majority of patients were treated with gamma knife, a significant proportion was judged to be suited for Linac treatment. This lat- ter group included particularly patients who benefit from fractionated therapy. The availability of both delivery modalities accommodates the full range of intracranial stereotactic indications and allows treatment technique to be tailored to the individual patient's needs.
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The Rotating Gamma System GammaART-6000: A review of the first 100 patient treatments PS3-4 Tomasz K., Helenowski (1) (1) Stereotactic Radiosurgery Institute - Neurosurgery Gurnee, USA The GammaART-6000 Rotating Gamma System has been in use at the Rotating Gamma System Institute in Gurnee, IL, USA, for over a year. The first 100 cases treated with the system are dis- cussed. Treatments for benign tumors, malignant tumors, and trigeminal neuralgia have been performed with this new technology.
Interstitial stereotactic radiosurgery PS3-5 Christopher, Ostertag Freiburg, Germany
ORAL SESSIONS 11h30 – 12h30
FUNCTIONAL RADIOSURGERY 1 OS16 Chairmen: Douglas, Kondziolka; Motohiro, Hayashi Room Nation
Radiosurgery of cavernous malformations associated with intractable seizures OS16-1 Yoshihisa, Kida (1) (1) Komaki City Hospital - Department of Neurosurgery Komaki Aichi, Japan Since the installation of gamma knife in 1991, we have treated 147 cases of symptomatic cav- ernous malformations(CMs) with radiosurgery. Among them there are 25 cases of CM associated with intractable seizure, which occurred more than twice a week. Complex partial seizures were predominant and followed by simple partial seizures. The mean age of the patients was 30.4 years. Almost all the lesions are located supratentorially, chiefly in temporal and frontal lobes. The mean diameter of lesions was 16 mm and the lesions were treated by gamma knife with the mean maximum dose of 31.4 Gy and mean marginal dose of 17.3 Gy. In the mean follow-up period of 49 months, seizures disappeared in 7, considerably decreased in 7, and unchanged in 10. Meanwhile 11 lesions decreased and 14 were unchanged in size on follow-up MRIs. Four cases were operated on because of hemorrhage (2) and uncontrollable seizure(2). In conclusion, seizures associated with supratentorial CMs are improved after the radiosurgery in a half of the cases. Since the seizure focus which is available with MEG are always outside and adjacent to the lesions, these informations should be incorporated into the planning of radiosurgery in order to improve the seizure outcomes.
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Gamma knife radiosurgical thalamotomy for essential tremor: a six year experience OS16-2 John, Lee (1); Joseph, Ong (2); Douglas, Kondziolka (3) (1) Hospital of the University of Pennsylvania - Neurosurgery; (2) University of Pittsburgh Medical Center - Department of Neurosurgery; (3) University of Pittsburgh Medical Center - Department of Neurological Surgery Philadelphia, USA INTRODUCTION: Essential tremor is the most common adult movement disorder. Those affected are often forced to change jobs or retire early, since symptoms are typically progressive and dis- abling. For patients who fail medical management, surgical options include thalamic deep brain stimulation (DBS) and gamma knife thalamotomy. In this study we examine the effectiveness and safety of gamma knife thalamotomy in treating essential tremor. METHODS: We reviewed the medical and imaging records of 23 patients who underwent gamma knife thalamotomy for refrac- tory essential tremor over an 8-year interval. There were 12 men and 11 women with an aver- age age of 75 years. The average duration of tremor was 18 years. The target in all cases was the ventralis intermedius thalamic nucleus based on standard AC-PC line coordinates. Stereotactic radiosurgical thalamotomy was performed using the model U Leksell gamma knife. A central dose of 130 to 140 Gy was delivered with a single 4 mm isocenter. Items from the Fahn-Tolosa clini- cal tremor rating scale were used to grade tremor and handwriting before and after treatment. RESULTS: Three patients were lost to follow-up. The average follow-up period was 17 months. The mean preoperative Fahn-Tolosa tremor and scores was 3.8 ± 0.4, and after radiosurgery was 1.4 ± 1.2. The mean preoperative Fahn-Tolosa writing score was 2.6 ± 1.0, and after radio- surgery was 1.3 ± 1.1. Two patients had no significant tremor relief after the procedure. Two patients had post-procedure right arm weakness and dysarthria, and minor weakness persisted in both cases. There were no other complications associated with the procedure. CONCLUSIONS: gamma knife thalamotomy for essential tremor is effective and has an acceptable complication rate. For patients with essential tremor who fail medical management and are poor DBS candi- dates or refuse DBS, Gamma knife thalamotomy is a reasonable minimally-invasive alternative.
Gamma knife radiosurgery - an alternative for intractable mesial temporal lobe epilepsy OS16-3 Sujoy, Sanyal (1); V P, Singh (2); V S, Mehta (2) (1) All India Institute of Medical Sciences - Neurosurgery Department; (2) All India Institute of Medical Sciences - Neurosurgery Department Calcutta, India INTRODUCTION The investigation of radiosurgery in the management of intractable Mesial Temporal Lobe Epilepsy (MTLE) is part of the quest of identification of novel therapeutic strategies for intractable epilepsy. METHODS 5 patients with MTLE were treated with gamma knife (GK) after obtaining an informed consent. Age ranged from 23-44 years and the duration of seizures pre- GK ranged from 6-23 years with a seizure frequency of 1-4/wk. MRI revealed right mesial tem- poral sclerosis (MTS) in 3, left MTS in 1 and bilateral MTS (left>right) in 1. Video-EEG and SPECT corroborated MRI findings. In the 5th patient, VEEG and SPECT localized to the left side which was therefore treated. The target volumes of 6.9-7 cc encompassed the amygdala (sparing the supero-medial part), the head and anterior half of the hippocampal body and the anterior part of 158 Oral Presentations Abstracts
the parahippocampal gyrus. Two 18 mm collimators delivered a dose of 25 Gy to the 50% iso- dose which corresponded to the target volume margin. RESULTS 4 patients developed radiation reactions extending into the temporal lobe white-matter at 8, 12, 13 & 14 months respectively. 1 patient lost to follow-up did not develop a reaction till 10 months when seizures had decreased marginally. All 4 who developed a radiation reaction experienced a dramatic decrease in seizures at the same time and went on to complete seizure remission. They have been followed for 2 years and all remained seizure and aura free except 1 patient who had 1 seizure on aggressive drug withdrawal. Oral steroids were started at the time of appearance of the radiation reactions which were tapered depending on their resolution which took around 5-11 months. 1 patient devel- oped dysphasia with mild right facial paresis which recovered following administration of methyl- prednisolone. 1 other patient was symptomatic for the radiation changes with diplopia which recovered. None developed raised intracranial tension, cognitive deficits or visual field defects or any steroid-induced complications. CONCLUSIONS Radiosurgery seems to offer the option of seizure control while sparing normal brain tissue and function unlike most surgical procedures but requires more investigation. Though lower doses avoiding radiation reactions may be effective if followed for longer, the optimal dose for seizure control within a reasonable time-frame for MTS seems to be around 25 Gy to the target volume margin.
Does dose rate affect efficacy? The outcomes of 256 gamma knife radiosurgery procedures for facial pain as they relate to the half-life of cobalt OS16-4 Christopher, Balamucki (1); Thomas, Ellis (2); Alan, deGuzman (3); Edward G., Shaw (3); Michael, Munley (3); Stephen, Tatter (2); Kenneth, Ekstrand (3); William, Huang (3); Daniel, Bourland (3); Kevin, McMullen (3); Charles, Branch (2); Lovato, James (4); Volker W., Stieber (3) (1) Wake Forest University - School of Medicine; (2) Wake Forest University School of Medicine - Department of Neurosurgery; (3) Wake Forest University School of Medicine - Department of Radiation Oncology; (4) Wake Forest University School of Medicine - Public Health Sciences Winston-Salem, USA Introduction: A biological model taking into account repair and dose rate suggests that over the range of typical treatment times of 25-60 minutes, the biologically effective dose (BED) could vary up to 31%. We examined whether the decrease in dose rate and increase in treatment time over 4.6 years between cobalt source replacement at our institution affected the control rates of facial pain for patients undergoing GKRS. Clinical Material and Methods: Between September 1999 and March 2004, 326 GKRS procedures for patients with facial pain were performed. The outcomes for 256 evaluable patients were analyzed. The biological model used was that developed by Thames and Nilsson for continuous radiation. Logistic regression was used to model the logit of response as a function of treatment time. The resulting coefficient was converted to an estimat- ed probability of response at the range of typical treatment times, 25 and 60 minutes. These esti- mated probabilities were compared to yield the estimated difference of BED from 25 to 60 min- utes. This difference was used to back-calculate a clinical value for the nerve repair half-time (T _). Results: The statistical analysis of the dose rate accounted for changes in prescription dose over time in order to prevent prescription dose from being a confounding variable. Neither dose rate nor treatment time were significantly associated with either the control rate or degree of pain relief. The estimated difference of BED from 25 to 60 minutes (95% CI) was – 11%. Calculating 159 Oral Presentations Abstracts
backwards, this resulted in a T_ = 1.28 hours. Discussion: The model appeared to accurately predict that the relative biologic efficacy would remain constant for a fixed prescription dose, regardless of dose rate. The T_ we have calculated should be interpreted as a clinical value in the context of GKRS.
IMAGING - ARTERIOVENOUS MALFORMATIONS OS17 Chairmen: Philippe, David; Enrico, Motti Room Permeke & Rembrandt
Imaging development for dose planning of radiosurgery: Three dimensional MR (DRIVE) images and MR angiography OS17-1 Hiroshi K., Inoue (1) (1) Institute of Neural Organization - Restorative Neurosurgery Fujioka, Japan To avoid radiosurgical complications of vascular and cranial nerve insults, exact evaluation of these structures are necessary before dose planning. Three dimensional magnetic resonance (3D- MR) images and MR angiography are used for the evaluation of lesions and their relationship between arteries, cranial nerves and brain structures. 3D-MR images were reconstructed using 3D-MR angiogram (TOF), MR image of cisternal structures (DRIVE) and MR image of lesions obtained from Gd-enhanced images. MR images were transported with DICOM files to a person- al computer and 3D images were reconstructed and exported using the software of ExaVision (Ziosoft). Fusion images of MRA and DRIVE-image were made using the software of Gyroscan Intera (Philips). 3D-MR images were useful for detection of lesions in relation to vascular and neu- ral structures in the basal cistern, cavernous sinus, petrous and clivus bone. In trigeminal neural- gia, the exact point of vascular compression was visualized on 3D-MR images of nerves in rela- tion with the whole length of related vessels. Exact evaluation of structures was helpful for exclu- sion of the important part from prescribed isodose lines. 3D-MR DRIVE image and MRA TOF image are useful for dose planning of radiosurgery.
Integration of three-dimensional corticospinal tractography into treatment planning for gamma knife radiosurgery OS17-2 Keisuke, Maruyama (1); Kyousuke, Kamada (1); Masahiro, Shin (1); Daisuke, Itoh (2); Shigeki, Aoki (4); Yoshitaka, Masutani (4); Masao, Tago (4); Takaaki, Kirino (1) (1) University of Tokyo Hospital - Department of Neurosurgery; (2) University of Tokyo Hospital - Radiology Tokyo, Japan Object. In the radiosurgical treatment of critically located lesions, the effort to minimize the risk of complication is essential. In this study the integration of diffusion tensor (DT) imaging-based trac- tography was clinically applied to treatment planning for gamma knife radiosurgery (GKRS). Methods. Seven patients with cerebral arteriovenous malformations located adjacent to the cor- ticospinal tract (CST) underwent this technique. Data provided by DT imaging were acquired before the frame was affixed to the patient's head and the CST of DT tractography was created using our original software. Stereotactic three-dimensional imaging studies were obtained after frame fixation and then coregistered with the data from DT tractography. After image fusion of 160 Oral Presentations Abstracts
the two studies, the combined images were transported to a GKRS treatment-planning worksta- tion. The spatial relationship between the dose distribution and the CST was clearly demonstrat- ed within the 2 hours it took to complete the entire imaging process. The univariate logistic regression analysis of transient or permanent motor complications revealed a significant inde- pendent correlation with the volume of the CST that received 25 Gy or more and with a maxi- mum dose to the CST (p<0.05). Conclusions. The integration of DT tractography into the GKRS treatment planning was highly useful in confirming the dose to the CST during treatment plan- ning. (JNS 102: 673, 2005).
Target definition in radiosurgery of AVMs using digital subtraction angiography time series OS17-3 Harald, Treuer (1); Moritz, Hoevels (1); Stefan, Hunsche (1); Mohamad, Maarouf (1); Jürgen, Voges (1); Martin, Kocher (2); R.-P., Müller (6); V., Sturm (1) (1) University of Cologne - Department of Stereotaxy; (2) University of Cologne - Klinik für Strahlentherapie Köln, Germany Successful radiosurgery of arteriovenous malformations (AVMs) requires accurate and complete localization of the nidus. Although not full three-dimensional, two plane digital subtraction angiography (DSA) is the state of the art imaging modality for AVMs, mainly due to the high con- trast and high temporal resolution. Unfortunately, many treatment planning systems do not sup- port nidus localization on time series, but only on a very limited number of single time frames. We have developed a software tool that takes advantage of the high temporal resolution and the high contrast of DSA and minimizes some of the drawbacks of DSA, i.e. image distortion, poor visibility of the fiducials on subtraction images, and high image noise. The program automatical- ly imports and sorts dicom images into angiographic times series and calibration images. The cal- ibration images of a grid phantom are semi-automatically analyzed for image distortions and cor- responding patient images are appropriately unwarped. Then, for each time series the fiducials are segmented manually on the unsubtracted mask image. Now the nidus may be outlined, visu- alized and edited on any of the images of a time series. For noise reduction, temporal filtering is supported as well as cine mode display with adjustable speed. The ROIs of corresponding later- al and frontal image series are exported, together with the segmented fiducials, to our treatment planning software (STP3.5) for further processing. The program was put to clinical routine in Feb/2005 and readily accepted. Especially the availability of complete time series in the stereo- tactic treatment planning computer was found to be very helpful in target definition.
Stereotactic radiosurgery patient response: 3-phase diary study OS17-4 Janet, Williams (1); Robert, Smee (2) (1) University of New South Wales - Prince of Wales Hospital - Department of Radiation Oncology; (2) Prince of Wales Hospital - Department of Radiation Oncology Randwick, Australia PURPOSE: In Australia, 1400 people are diagnosed with a brain tumour every year. There are 40 major types of brain tumours including benign tumours, primary malignant neoplasms and second- ary malignancies arising from other primary sites. This ethics approved prospective study investi- gates the symptom profile and emotional functioning for patients undergoing stereotactic radio- surgery. This is a 3-phase study assessing patients at baseline (pre-radiosurgery), 1 week and 3 161 Oral Presentations Abstracts
months post SRS using diary format measuring mood state and physical symptoms using the Likert scale. MATERIALS AND METHODS: Questions included in this study were based on the experiences of 100 previously treated stereotactic patients. The purpose of this study is to assess the emotional and physical state of the patient at the time of SRS and measure the changes in their physical symp- toms in relation with their emotions. Phase 1 diary is to establish the physical and emotional pro- file of the patient at treatment, phase-2 is collected one week post SRS and assess the changes in their emotions with their physical symptoms. Phase-3 of the study at three months post SRS again assesses the fluctuations of the patient’s responses. It is anticipated that during the three month period post SRS, the emotional state of the patient will improve, the radiosurgery side effects will subside and the patient’s mood state will improve. It is anticipated that p=50 for initial analysis. RESULTS: Feedback from patients is encouraging and has confirmed that on reflection, the events of the day’s procedure were not as physically or emotionally draining as anticipated. CONCLUSION: At initial analysis it is anticipated there will be sufficient data to analyse the responses at the time of SRS treatment, changes in physical symptoms and responses to their emotions and evaluate the overall improvement of the emotional state and general health status of the patient.
EXTRACRANIAL RADIOSURGERY 1 OS18 Chairmen: David, Larson; John, Buatti Room Willumsen
A prospective trial on stereotactic radiotherapy of colo-rectal metastases OS18-1 Morten, Hoyer (1); Henrik, Roed (2); Anders, Traberg Hansen (1); Lars, Ohlhuis (2); Jorgen, Petersen (1); Hanne, Nellemann (3); Anne Kiil, Berthelsen (2); Cai, Grau (1); Sv. Aage, Engelholm (2); Hans, von der Maase (1) (1) Aarhus University Hospital - Department of Oncology; (2) Copenhagen University Hospital - Department of Oncology; (3) Aarhus University Hospital - Department of Diagnostic Radiology Aarhus C, Denmark Large retrospective studies have shown that resection of colo-rectal metastases (CRM) in the liver results in long term survival of 25-30% of the patients. Unfortunately, more than 80% of patients with CRM of the liver and even more patients with extrahepatic CRM are considered inoperable. Radio-frequency ablation and stereotactic body radiotherapy (SBRT) are alternatives to resection and they may increase the number of patients that can receive local treatment for CRM. We have tested the effect of SBRT in the treatment of patients with CRM in a phase II trial. Sixty-nine patients with each 1-6 CRM in liver, lung or suprarenal gland were included into the trial. The patients were immobilized by the Elekta stereotactic body frame (SBF) or a custom made body frame. SBRT was given on standard LINAC with standard multi-leaf collimator. Central dose was 15 Gy x 3 within 5-8 days. Preliminary results of the study showed that 82% of the tumours were controlled by SBRT. Only 75% of the patients had overall local control since they were treated for more than one tumour. Due to progression elsewhere, only 15% were without progression and 28% were alive 2 years after treatment. No difference in survival was observed between patient treated for hepatic- or extra-hepatic CRM. In general, toxicity was limited. However, 47% of the patients experienced grade> 1 toxicity within 6 months after SBRT. Most frequent side effects were nausea, diarrhoea, pain and skin reaction. SBRT in patients with CRM resulted in high prob- ability of local control and acceptable survival rate. The toxicity after SBRT of CRM was moderate. The final results with more than 2,5 years follow-up time will be presented at the meeting. 162 Oral Presentations Abstracts
Stereotactic body radiation therapy of early stage non-small cell lung carcinoma: phase I study update OS18-2 Ronald, McGarry (1); Robert, Timmerman (2); Lech, Papiez (3); Mark, Williams (4) (1) Indiana University Medical Center - Department of Radiation Oncology; (2) University of Texas Southwestern - Department of Radiation Oncology; (3) Indiana University Medical Center - Department of Radiation Oncology; (4) Richard L. Roudebush V.A. Medical Center - Pulmonary Division Indianapolis, USA Purpose ¨C a phase I dose escalation study of stereotactic body radiation therapy (SBRT) to assess toxicity and local control rates for patients with medically inoperable Stage I lung cancer. Materials and Methods - All patients had non-small cell lung carcinoma, stage T1a or T1b, N0, M0. All patients had significant cardiovascular and/or pulmonary pathology which prohibited surgical resection. Patients were immobilized in a stereotactic body frame and treated in escalating doses of radiotherapy beginning at 24 Gy total (three 8 Gy fractions) using 7-10 beams. Cohorts were dose escalated by 6.0 Gy total with appropriate observation periods. Most patients received PET scans as a staging evaluation and preliminary analysis will be available. Results - The maximum tolerated dose (MTD) was not achieved in the T1 stratum (maximum dose = 60 Gy), but within the T2 stratum, the MTD was realized at 72 Gy for tumors larger than 5 cm. Dose limiting toxic- ity included predominantly bronchitis, pericardial effusion, hypoxia, and pneumonitis. Local fail- ure occurred in 4/19 T1 and 6/28 T2 patients. 9 local failures occurred at doses ¡Ü16 Gy and only 1 at higher doses. Local failures occurred between 3-31 months from treatment. Within the T1 group, 5 patients had distant or regional recurrence as isolated events, where as 3 patients had both distant and regional recurrence. Within the T2 group, 2 patients had solitary regional recur- rences and the 4 patients who have failed distantly also failed regionally. A single patient autop- sy result showed only interstitial fibrosis in the treated are with no residual tumour. Conclusions - SBRT appears to be a safe, effective means of treating early stage lung cancer in medically inop- erable patients. Excellent local control was achieved at higher dose cohorts with dose-limiting toxicities achieved in patients with larger tumors.
Stereotactic radiotherapy for liver tumours based on MRI and tumor markers OS18-3 Alejandra, Mendez Romero (1); Wouter, Wunderink (2); Shahid M, Hussain (3); Peter JCM, Nowak (4); Ben JM, Heijmen (5); Joost, Nuyttens (6); Rene P, Brandwijk (7); Jan NM, Ijzermans (8); Peter C, Levendag (9) (1) Erasmus MC - Radiotherapy; (2) Erasmus MC - Radiotherapy; (3) Erasmus MC - Radiology; (4) Erasmus MC - Radiotherapy; (5) Erasmus MC - Radiotherapy; (6) Erasmus MC - Radiotherapy; (7) Erasmus MC - Radiotherapy; (8) Erasmus MC - Surgery; (9) Erasmus MC - Radiotherapy Rotterdam, The Netherlands Purpose: To evaluate tumor response based on serial pre-and post MRI imaging and tumor mark- er values as well as toxicity after treatment with Stereotactic Radiotherapy (SRT) for primary and metastatic liver tumours. Methods and Materials: Between October 2002 and March 2005, 17 patients with 32 lesions, not suitable for other local treatments, underwent SRT. The lesions included 8 hepatocellular carcinoma (HCC), 7 patients, and 22 metastases (Mets), 10 patients. Median follow-up is 14 months (range: 4-27). Median size was 4.5 cm (range: 0.5-7.2). Treatment schemes were 3 x 12.5 Gy at the 65% for liver metastases and HCC < 4 cm and 5 x 5 Gy or 3 fractions of 8-10 Gy at the 65% for HCC > 4 cm. All lesions were evaluated with MRI 163 Oral Presentations Abstracts
and tumour markers, carcinoembryonic antigen (CEA) or alpha-fetoprotein (AFP), before treat- ment and periodically after that. Local failure was defined as increase in tumor size and/or increas- ing tumor marker without evidence of new lesions, at any point during the follow-up. Acute tox- icity was scored following the Common Toxicity Criteria v 2.0 and late toxicity with the SOMA/ LENT classification. Results: Local failure was observed in 2 of 32 lesions ( 6.3%) in 2 of 17 (11.8%) patients. Both patients were treated with 5 x 5 Gy. Retreatment was performed with 3 x 8 Gy. One lesion stays in local control and the other one underwent surgery. Acute toxicity grade ¡_3 was seen in 1 HCC patient who presented liver decompensation together with an infection and died (grade 5). One late toxicity was observed in 1 patient with metastases who developed a portal hypertension syndrome with one episode of melena (grade 3) Conclusions: The results show that stereotactic radiotherapy for liver tumors offers the possibility of excellent local control with acceptable toxicity in otherwise untreatable patients.
Stereotactic radiation treatment (SRT) for advanced intra- abdominal tumours OS18-4 Vincent, Vinh-Hung (1); Frederik, Vandenbroucke (2); Zsuzanna, B Nagy (1); Hilde, Van Parijs (1); Maria, Voordeckers (1); Jan, Van de Steene (1); Guy, Soete (1); Dirk, Van Den Berge (1); Johan, De Mey (2); Guy, Storme (1) (1) AZ VUB - Radiothérapie; (2) AZ VUB - Radiologie Brussels, Belgium Purpose: To evaluate our experience with the Novalis SRT in advanced abdominal tumours. Methods: A search of our database for patients treated in 2000-2004 with SRT for inoperable pri- mary or metastatic abdominal tumours retrieved 91 cases. Survival estimates were computed by the product-limit method. Multivariate analyses used proportional hazards. Variables included were age, gender, tumour size, radiation treatment duration and doses. Results: Localizations were: liver 56 cases (62%), pancreas 7 (11%), other 28 (46%). Mean tumour size was 6.4 cm (range 1.8-12.5 cm). Mean number of sites treated was 1.5 (1-6). Fraction doses were mainly 4-10 Gy, 3-10 fractions, mean duration 6 days (2-48). Treatment was delivered under X-ray image guidance (XRG). XRG was based on implanted metal markers in 23 patients, based on bone structures in others. Overall survival (OS) was 25 months, local progres- sion free survival (PFS) 13 months, and time to response (TTR) 10 months. Use of markers was associated with better PFS (median 16 vs. 12 months without marker), and better TTR (median 4 vs. 10 months, P=0.008). In multivariate analyses, factors associated with improved survival and response were: higher radiation doses, P=0.001 for OS, P<0.001 for PFS, P=0.007 for TTR, and smaller number of fractions, P=0.05 for PFS, P=0.07 for TTR. Conclusion: The dose-effect relationship suggests that the utility of local control should not be dismissed in metastatic cases. Furthermore, improved time to response using markers indicates that palliative cases might benefit from high precision treatment.
164 Oral Presentations Abstracts
ORAL SESSIONS 14h00 - 15h00
FUNCTIONAL RADIOSURGERY 2 OS19 Chairmen: Douglas, Kondziolka; Motohiro, Hayashi Room Nation
Gamma knife radiosurgery to the pituitary for thalamic pain syndrome: clinical evaluation of recent our institutional series OS19-1 Motohiro, Hayashi (1); Takaomi, Taira (2); Taku, Ochiai (1); Mikhail, Chernov (1); Shinichi, Goto (2); Koutaro, Nakaya (1); Masahiro, Izawa (1); Tomokatsu, Hori (1) (1) Tokyo Women's Medical University - Department of Neurosurgery; (2) Tokyo Women's Medical Univeristy - Department of Neurosurgery Tokyo, Japan Rationale: Thalamic pain syndrome is one of represented intractable pain. However, there was one clinical report, it could be controlled with chemical hypophysectomy with developing to tran- siently diabetes insipidus. This historical evidence prompted us to perform Gamma knife radio- surgery (GKR) to the normal pituitary gland–stalk in aiming to try to control of this kind of intractable pain. Material and Method: An indication of this treatment for our proposal indication: 1) The pain should be typical thalamic pain syndrome, 2) No any other effective treatment prior to GKR, 3) Patients with poor condition, which means impossible to be treated under general anesthesia , 4) Main complaint is “pain”, not “numbness”. In our institutional series experience, we have treated 27 patients who were suffered from thalamic pain syndrome with GKR, whose onset was cerebral infarction/ hemorrhage in 26, and was malignant lymphoma in one. The tar- get was the just pituitary gland involving a part of the pituitary stalk with 8mm collimator. Prescribed maximum dose was 140 to 180Gy. We could follow up more than 6 months and eval- uate the 24 patients. Results: Initial significant pain reduction was observed in 70.8% (17/24). All effective cases experienced significant pain reduction within 4 days. Long term effective (>1 year) was observed in 25.0% (5/20). No any important postoperative complication was observed excluding only two patients who developed transiently diabetes insipidus. Conclusions: Thalamic pain syndrome is still too difficult to be cured with any treatment protocol. However, we have pro- vided significant pain reduction and overcoming daily life to the majority of the patients, who were treated by GKR to the pituitary. Otherwise, we should know why GKR to the pituitary is effective for this kind of pain on not only clinical but also experimental aspect. We suppose that GKR to the pituitary has an overestimated potential and will play an important role in the field of the management of intractable pain.
Gamma knife radiosurgery for symptomatic trigeminal neuralgia. How should we select the treatment strategy ? OS19-2 Hiroyuki, Kenai (1); M, Yamashita (1); T, Nakamura (1); T, Asano (1); M, Saino (1); H, Nagatomi (1) (1) Nagatomi Hospital - Department of Neurosurgery Oita, Japan Introduction For the treatment of essential trigeminal neuralgia(TN), Gamma knife radiosurgery(GKRS) is widely adopted now. But there are few reports about GKRS for symptomatic TN which caused by the tumor, AVM, etc.. Generally, pains of symptomatic TN are controlled ear- lier than essential TN by GKRS for the lesion. We also have experienced some symptomatic TN. 165 Oral Presentations Abstracts
Here we summarized the results of our cases and reviewed the strategy of GKRS for symptomatic TN. Methods From January 2001 to December 2004, seventeen patients suffering from sympto- matic TN were treated with GKRS in our institution. Of them, fourteen patients that could be fol- lowed for a minimum of 6 months were retrospectively examined. The mean follow-up was 23.9months. There were 4 men and 10 women with a mean age of 73.7years(range, 58-82). Results In 10 of 14 cases, pains could be controlled by GKRS for the lesion. But in some cases, pains could not be controlled in spite of the lesion control through GKRS. In these cases, pains could be controlled by adding GKRS of targeting the fifth nerve directly. And, in the cases that GKRS was not indicated for treatment of the lesion or in the cases of emergency, using or adding the same GKRS for essential TN from the first was effective. Conclusions We reviewed the strate- gy of GKRS for symptomatic TN from our experienced cases. In some symptomatic TN cases, pains could not be controlled only by the lesion control through GKRS. Although GKRS for symptomatic TN should be directed to the lesion rather than the trigeminal root originally, it was indicated that using or adding the same GKRS for essential TN was effective and safe for the treatment of symp- tomatic TN.
Influence on pain outcome of the neurovascular compresion anatomy on MRI in patients with idiopathic trigeminal neuralgia treated by gamma knife radiosurgery OS19-3 José, Lorenzoni (1); Philippe, David (2); Nicolas, Massager (3); Daniel Salvador, Ruiz Gonzalez (4); Françoise, Desmedt (1); Jacques, Brotchi (3); Marc, Levivier (1) (1) Hôpital Erasme - Centre Gamme Knife; (2) Hôpital Erasme - Neuroradiologie; (3) Hôpital Erasme - Neurochirurgie; (4) Medica Sur SA de CV MSU 820125 T58 - Unidad Gamma Knife Brussels, Belgium Objective: To study the relationship between the pain outcome and the anatomical characteristics of the neurovascular compression on MRI in patients with idiopathic trigeminal neuralgia treated by gamma knife Radiosurgery. Material and Methods: Analysis of the anatomy of trigeminal nerve, brain stem and the vascular structures related to the nerve was made in 100 consecutrive patients treated by Leksell gamma knife for ITN. One mm thick axial slices MRI (T1, T1 enhanced and T2 SPIR) with coronal and sagital reconstructions was viewed in a dynamic manner using the software GamaPlan. Three-dimensional reconstructions were made as well. Pain outcome was considered excellent if there was total pain remission and no medication was needed. 89 of these patients have follow up of 6 months or more. Results: In 93 patients (93%), one or more vascular struc- tures in contact with the trigeminal nerve or the brain stem near the nerve insertion were found. Superior cerebellar artery was in 71 cases (76%). Other vessels identified were the antero-inferior cerebellar artery, basilar artery, vertebral artery, and some veins. In 39 patients (42%), vascular con- tact was located proximally (less than 3mm to the brain stem) and in 42, (45%) in a distal loca- tion. Nerve dislocation by the vessel was observed in 30 cases (32%), and nerve atrophy in 25 (27%). The two variables associated with a poor outcome were a proximal nerve compression and a great vessel contacting the nerve (basilar or vertebral artery). The dose received by the nerve at the neurovascular compression as well as nerve atrophy or nerve dislocation by the vessel was not associated to pain outcome. Conclusions: The anatomical characteristics of trigeminal nerve com- pression could be important in predicting pain outcome in patients with ITN treated by radio- surgery. This approach could be ussefull also, for the planification of an open surgery for ITN. 166 Oral Presentations Abstracts
Different targets in the gamma knife treatment for intractable pain OS19-4 Dusan, Urgosik (1); Roman, Liscak (2); Josef, Novotny Jr. (3); Josef, Vymazal (4); Vilibald, Vladyka (5) (1) Na Homolce Hospital - Stereotactic and radiation neurosurgery; (2) Na Homolce Hospital - Stereotactic and radiation neurosurgery; (3) Na Homolce Hospital - Medical physics; (4) Na Homolce Hospital - Stereotactic and radiation neurosurgery; (5) Na Homolce Hospital - Stereotactic and Radiation Neurosurgery Prague, Czech Republic Introduction: Various pain syndromes require various therapeutic approaches. That was the rea- son, we used the different targets for gamma knife surgery (GKS) in different cases. Material and Methods: Since the end of 1995 we have used these targets for our pain patients: 1) The root entry zone (REZ) of trigeminal nerve for trigeminal neuralgia (TN), 2) ganglion sphenopalatinnum for sphenopalatine neuralgia, 3) ganglion inferior of the ninth cranial nerve for glossofaryngeal neuralgia, 4) ganglion ciliare for vegetative orbital pain, 5) medial parts of thalamus for thalam- ic pain and unilateral pain of other origin, 6) rostral parts of gyrus ciguli mainly for pain of malig- nant origin, 7) pituitary gland for pain caused by skeletal metastatis of different types of cancer. All targets were irradiated by Leksell gamma knife. In majority of anatomical structures we have used a 4 mm collimator and single shot, only for hypophysectomy 8 mm collimator has been applied and for cingulotomy four shots with 4 mm collimators. A maximal dose has ranged from 70 to 80 Gy in the case of cranial nerves irradiation, 150 Gy in the thalamic target, from 160 to 200 Gy in hypophysectomy and 150 Gy has been applied during cingulotomy. Results: The best initial pain relief (successful rate to 96%) was reached after GKS in REZ area for essential TN. Also hypophysectomy for cancer pain was successful (rate to 75%). Only partially satisfactory results were achieved after thalamotomy and cingulotomy (successful rate to 50 %). Conclusion: Versatility and accuracy of GKS allow us to treat the patients with various types of pain. GKS is the method of the first choice in TN patients and appropriate complementary method in other pain syndromes.
PHYSICS - NEWS OS20 Chairmen: Frank, Bova; Dirk, Verellen Room Permeke & Rembrandt
Image-guided and frameless localization in cranial stereotactic radiotherapy OS20-1 Joachim, Bogner (1); Beverly, Downes-Phillips (2); Dietmar, Georg (3); David W., Andrews (2) (1) Medical University Vienna - Radiotherapy and Radiobiology; (2) Jefferson Hospital for Neuroscience - Department of Neurosurgery; (3) Medical University Vienna - Radiotherapy and Radiobiology Vienna, Austria Purpose: The purpose of this study is to assess the accuracy of ExacTrac X-ray as a patient posi- tioning device for stereotactic radiosurgery (SRS) and fractionated stereotactic radiotherapy (FSRT) in cranial applications. Specifically, a new approach of frameless localization is commissioned for various stereotactic immobilization devices and compared to conventional stereotactic patient positioning with a target positioning box. Material and Methods: New software developments in BrainSCAN and ExacTrac X-ray enable direct transfer of isocenter coordinates and CT data sets of cranial patients. Thus, a comparison of isocenter position between the frameless localization of 167 Oral Presentations Abstracts
ExacTrac X-ray and the localization by means of a target positioning box is possible. Measurements were performed with a RANDO head phantom, which was fixated in three differ- ent stereotactic immobilization devices (head-ring for SRS, stereotactic mask and a bite-block sys- tem for FSRT). Based on spiral CT scans with 1.5 mm slice thickness two isocenters were set, resembling either a tumor position near optic structures or in a posterior, parietal position. In addi- tion a sequential CT scan with 2 mm slice thickness was recorded in order to check the influence of DRR quality to the resulting isocenter position and we studied the impact of different X-ray energies and DRR grey-scale parameters. Finally the response of the localization system to inten- tional couch translations in vertical, longitudinal and lateral directions starting from an optimized isocenter position was investigated. Results: Averaged over all tumor sites and fixation devices the difference between the isocenter determined by ExacTrac and the isocenter determined by tar- get positioning box is 0.10 ± 0.40 mm, 0.05 ± 0.31 mm, and -0.77 ± 0.42 mm in longitudi- nal, lateral and vertical direction, respectively. Angular deviations were -0.03 ± 0.23º, -0.06 ± 0.13º, and -0.01 ± 0.17º for the longitudinal, the lateral and the isocentric table axis, respec- tively. No significant difference in isocenter position was found employing either the 2 mm sequential or the 1.5 mm spiral CT sequence. For both tumor positions simulated the rather severe artefacts from the respective immobilization device in the X-ray images showed no signif- icant influence on target precision. The dependence of the ExacTrac precision on the parameters X-ray energy and DRR settings is small. Only complete lack of bony anatomy in either the X-ray image or the DRR leads to variations of isocenter position greater than 1 mm. The response of ExacTrac X-ray to intentional couch translation of 2 mm, 4 mm, and 6 mm was found to be exact within 0.25 mm on average. Conclusion: ExacTrac X-ray provides a new tool for frameless stereo- tactic patient positioning. The present study on various phantoms and immobilization devices can successfully demonstrate the high accuracy of the system to be well within the required tolerances for SRS/FSRT. A patient study comparing the repositioning accuracy of stereotactic mask and bite- block system with the help of ExacTrac X-ray is in progress.
Treatment of ocular melanoma; X-Knife treatment planning with optimal immobilization OS20-2 Sandra, de Vries (1) (1) Otago University - Radiation Therapy Dunedin, New Zealand In 2001 the first Stereotactic Radiotherapy treatment of an Ocular Melanoma was performed at the Dunedin Oncology department. Since then another 13 cases have been treated. The principal aim is to achieve tumour control and preservation of the eye without unduly compromising sight. The Gill-Thomas-Cosman relocatable headframe was used to accurately immobilize the head. To fixate the eye a light source was used and the treatment was given under video surveillance. X- Kife was used to plan the treatment. This presentation/poster will discuss the disease, diagnostic methods, current treatment options and the rationale for treatment with Stereotactic Radiotherapy. The presentation will also describe the immobilization of the eye and the technical difficulties encountered defining the tumour volume within stereotactic coordinates. The method of immobilization used in Dunedin results in delivery of a high dose of radiation to the eye that can be given with a relocation accuracy of 1mm. 168 Oral Presentations Abstracts
Initial experience with a x-ray based respiratory gating system for lung and liver OS20-3 Franz, Gum (1); Reinhard, Wurm (1); Armin, Fuerst (2); Volker, Budach (1) (1) Charité University Medicine Berlin - Department of Radiation Oncology; (2) BrainLAB - Radiotherapy Berlin, Germany Purpose/ Objective: A commercially available, x-ray based image guidance system (Novalis Body / ExacTrac X-Ray 6D, BrainLAB) has been modified to allow respiration triggered treatments. A commercially available, x-ray based image guidance system (Novalis Body / ExacTrac X-Ray 6D, BrainLAB) has been modified to allow respiration triggered treatments. Methods and Materials: The system features real-time tracking of the patients’ external breathing signal via infrared reflec- tive markers attached to the patients’ skin and an infrared tracking device. Additionally, stereo- scopic x-ray images are acquired at user-defined moments within the patient’s breathing cycle to image the position of an implanted marker. As such a relation between the externally detected breathing curve and internal tumor motion can be established to first set-up the moving target correctly and second establish a gating window. To verify system performance and accuracy a special gating phantom, simulating a breathing pattern was developed. The phantom consists of a moving platform, a slab-phantom with film inserts and integrated radio-opaque markers. The markers are used for positioning and tracking. The phantom was used to assess: (a) the ability and accuracy of positioning a moving target to a specific point within the breathing pattern. Positioning verification was undertaken via a Winston-Lutz test on the positioned marker (b) the real-time capabilities of the system by measuring system latency (c) the correctness of the trigger- ing of the linear accelerator by performing a triggered Winston-Lutz test and (d) the verification of a treatment plan delivered under gating, which was matched on the moving slab phantom. First clinical application of the gating prototype system was performed on lung and liver patients. Therefore radio-opaque gold markers (Visicoil, RadioMed Inc.) were implanted into the tumor under CT / ultrasound guidance. Gated treatments were performed and the system capabilities were assessed to: (a) usability on real patients (b) x-ray tracking accuracy of the implanted mark- er (c) treatment efficiency and accuracy. Results: The data measured on the phantom was in good agreement with the expected data. No measurable delay in the triggering of the linac was observed. Set-up accuracy of the moving target was within the mechanical tolerance and meas- urement accuracy of the phantom. System latency, important for the real-time capability of the system was in the order of 200 msec. Treatment plans under gated delivery showed good agree- ment with the original theoretical dose distribution with the deviations depending on the gating window size. Patient treatments demonstrated the capabilities and limitations of the system in clinical routine. System performance was significantly dependent on patient, indication and tumor location. A fairly stable relationship between the external breathing signal and internal tumor motion was detected in the area of exhalation, which was also chosen for treatment. Verification images acquired during treatment showed a good overall agreement of marker position, with the deviations being dependent on tumor location and the amount of the entire tumor motion. Treatment times were in a range of 30 to 40 min, depending on gating window size, which was in the order of 25 to 30 %. Conclusions: Phantom tests and first patient treatments for breathing synchronized irradiation showed promising results. Certainty in accurately delivering radiation to the target and therefore the ability to reduce safety margins are the most important factors. With this new gating technology safety margins could already be reduced by a significant factor. The 169 Oral Presentations Abstracts
biggest issues arose from the often unstable and varying breathing signals of the patients. Further investigations are planned to overcome these related problems. Conflict of interest: This work has been supported in part by BrainLAB AG.
Evaluating the localization accuracy of 6D Fusion software for the Novalis body image guided system and its clinical application for spinal radiosurgery OS20-4 Jian-Yue, Jin (1); Samuel, Ryu (1); Jack, Rock (2); Kathleen, Faber (1); Marilyn, Gates (3); Shidong, Li (1); Benjamin, Movsas (1) (1) Henry Ford Hospital - Radiation Oncology; (2) Henry Ford Hospital - Neurosurgery Detroit, USA Purpose: Accurate target localization is key for spine radiosurgery because the target is usually close to the spinal cord, which may suffer irreversible injury if a high radiation dose is received. Recently, a 6D fusion algorithm, which takes into account rotational setup error, was clinically released. This study evaluates the localization accuracy of this software and its application in spinal radiosurgery. Materials and Method: BrainLab ExacTrac 3.5 and the Novalis radiosurgery unit were used in this study. An anthropomorphic torso phantom was implanted with six 2-mm diameter metal balls in the vertebral region. The phantom was scanned in a CT scanner with slice thicknesses of 2 mm and 3 mm respectively. The centers of the 6 metal balls were identified in the CT images, and one of the centers was used as the isocenter for treatment. The phantom was then positioned in the treatment couch with intentional translational and rotational offsets to the isocenter. Two X-ray images were taken and fused with the simulation CT images using (1) 3D fusion algorithm, (2) 6D fusion algorithm, and (3) implanted marker algorithm. For 3D and 6D fusions, the image areas with implanted metal balls were excluded. Localization accuracy for each algorithm was evaluated by comparing the fusion results. The phantom position was then read- justed according to the 6D fusion results. Two kV X-ray images were taken for the new position, and localization accuracy was evaluated by comparing the X-ray system’s isocenter position to the center of the metal ball in the images. Two MV portal films were also taken to further evaluate the localization accuracy related to the linac’s isocenter system. Results: We have tested 6 isocen- ters in different positions in the vertebral region. The localization accuracy related to the X-ray sys- tem’s isocenter for 6D fusion algorithm is 0.56 ±0.25 mm and 0.74±0.27 mm for 2 mm and 3 mm CT slice thicknesses, respectively. The localization accuracy related to the Linac’s isocenter is 0.72 ±0.12 mm and 0.74±0.2 mm for 2 mm and 3 mm CT slice thickness, respectively. The localization accuracy related to the implanted marker system (assuming the implanted marker is the golden standard) is 0.57±0.32 mm and 2.44±0.73 mm for the 6D fusion and 3D fusion algorithms, respectively. We have also used the 6D fusion software to localize the target for over 40 spine radiosurgery patients. The localization accuracy can be easily evaluated by comparing anatomic structures in the overlying kV X-ray images and the DRRs of the patient. In addition, comparing AP and lateral MV port films with the DRRs using the vertebral bone structure yielded further confidence that accurate target localization was achieved. Conclusion: The 6D fusion soft- ware can achieve sub-millimeter localization accuracy, even when the patient has a rotational setup error (up to 4 degrees). Unlike the accuracy of 3D fusion, the accuracy of 6D fusion is inde- pendent of rotational offsets. 170 Oral Presentations Abstracts
ORAL SESSIONS 15h00 - 16h00
FUNCTIONAL - TRIGEMINAL NEURALGIA 1 OS21 Chairmen: Joseph C.T., Chen; Jean, Régis Room Nation
Longterm clinical results for trigeminal neuralgia treated by gamma knife radiosurgery OS21-1 Noriko, Murata (1); Manabu, Tamura (2); Jean, Regis (3) (1) Timone University Hospital - Stereotactic and Fonctional Neurosurgery; (2) Timone University Hospital - Stereotactic and Fonctional Neurosurgery; (3) CHU La Timone - Service de Neurochirurgie Marseille, France Objective : To evaluate the long-term effect of gamma knife Radiosurgery (GKS) for typical Trigeminal Neuralgia. Material and Methods : Between December 1992 and May 2005, 325 patients underwent radiosurgery for trigeminal neuralgia in Marseille Timone University hospital. A minimum follow up of 1 year is available for 260 patients. All these patients have been treat- ed with an anterior target/high dose strategy. A multiple sclerosis was diagnosed in 21 patients 8%. A previous surgical treatment of the TN was applied in 39,6% patients (103/260). Results : The median follow up (FU) was 3,2 years (range 1-12,5). The median distance between the cen- ter of the shot and the emergence was 8,35 mm (range 4,3-16,8). The median dose at the cen- ter of the single 4mm collimator was 85 Gy (range 70-90). The median delay for pain cessation was 14 days (range 0-150). The initial pain free rate is 88,5 % (among 230 patients). Among these patient the number of patient still free of pain at 1 year, 2 years, 3 years, 4 years, 5 years, 6 years, 7 years and at the last FU was respectively 63,9% (46/72); 71,7% (38/53); 72,4% (21/29); 76,0% (19/25): 75,0% (21/28): 92.3% (24/26): 62,5% (10/16). At the last follow up among the total population 183 were still pain free (69,8%) and 101 still pain free without any medication (38,8%). Due to failure an additional surgery was performed in 58 patients (22,3%). At the last follow up a new hypoesthesia was observed in 45 patients (17.3 %) of 260 patients. Conclusion : This study shows that gamma knife Radiosurgery applied to the cisternal anterior Trigeminal Nerve using high doses provided safe and effective for treatment of Trigeminal Neuralgia in the long-term.
Outcome of patients undergoing gamma knife stereotactic radiosurgery for medically refractory idiopathic trigeminal neuralgia OS21-2 Kostas, Fountas (1); Joseph, Smith (2) (1) The Medical Center of Central Georgia - Department of Neurosurgery; (2) Medical College of Georgia - Neurosurgery Macon, USA The role of stereotactic radiosurgery in the management of medically refractory trigeminal neural- gia has been well established in the literature. However, a significant variation exists between the reportable success rate among different clinical series. In our retrospective clinical study, we pres- ent our experience in treating patients diagnosed with idiopathic trigeminal neuralgia with gamma-knife. In our institution during the last five years (2000-2004) 77 patients (54 females and 23 males) with the diagnosis of idiopathic trigeminal neuralgia underwent gamma knife 171 Oral Presentations Abstracts
radiosurgery on outpatient basis. Their mean age was 67.3 years while their age range was 42- 81 years. Stereotactic radiosurgery via a gamma-knife unit was applied in all of them. The mode administered dose was 80Gy at 100% isodose. Our follow-up time ranged between 6-60 months while our mean follow-up time was 21.1 months. Fifty-two patients (67.5%) had no previous procedures while 25 patients (32.5%) had previously undergone one or more surgical or percu- taneous procedures. The mean pain-free period was 15.9 months (range 0-60 months). Interestingly, the mean pain-free period among patients with no previous procedures was 23.6 months while the respective one for patients with previous procedures was 10.1 months. No intraoperative or late major complications occurred in our series. Five patients (6.5%) developed local clinical symptomatic post-radiation necrosis, which was medically treated. Eleven patients (14.3%) developed moderate to severe, post-treatment facial numbness. Stereotactic gamma- knife surgery represents a safe alternative treatment for medically refractory trigeminal neuralgia. In our series the pain free period appears to be shorter than previously reported in the literature. Patients with no previous procedures responded significantly better to gamma-knife surgery.
Outcomes of gamma knife radiosurgery in trigeminal neuralgia OS21-3 David, Huang (1); Danielle, Rudolph (2); Deane, Jacques (3) (1) Cancer Care Consultants/ Northridge Hospital - Radiation Oncology; (2) Independent CRA - CRA; (3) Good Samaritan Hospital - Neurosciences Institute Northridge, USA PURPOSE: gamma knife Radiosurgery (GKRS) is a treatment option used to control pain in patients with medically refractory trigeminal neuralgia (TN). However, its efficacy is sometimes limited and recurrences may develop. This study was done to assess the overall outcomes and patient satisfaction with this modality. MATERIALS AND METHODS: Between 1992 and 2004, 371 patients were treated for TN with GKRS in a single institution. All patients were treated using one 4 mm shot, targeting the trigeminal nerve at the pontine junction. The median dose pre- scribed was 87.2 Gy (range 65- 98.1 Gy). In 2004, a questionnaire was sent to all treated patients to assess long term outcomes. 108 patients responded to the questionnaires. Median follow up was 44 months (range 6-120 months). RESULTS: Out of the 108 evaluable patients, 92 patients (85.2%) initially demonstrated excellent or good pain control (feeling no further pain, without or with medications respectively) Nine patients (8.3%) felt they had fair pain control (feel- ing less pain). Seven patients (6.5%) failed treatment. At last follow up, only 62 patients (57.4%) had excellent or good pain control and 23 patients (21.3%) had fair pain control. Twenty-three patients (21.3%) had failure to control pain. Some recurrences were treated with repeat SRS in 29 patients (26.9%). Of these, 10 patients (34%) had excellent pain control, 3 (10.3%) had good pain control, and 8 (27.6%) had fair pain control. Eight patients (27.6%) failed retreatment. Mild complications (numbness, weakness, or paresthesias) occurred in 17 patients (15.7%) after the first procedure. Nine patients experienced complications after a second procedure, and the over- all rate of complications was 24.1%. The overall satisfaction rate was 77.8%. CONCLUSIONS: Despite recurrences, complications, and the need for repeat treatments, overall degree of pain control and satisfaction rates remain good for GKRS used for TN.
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Gamma knife radiosurgery as primary surgery for patients with trigeminal neuralgia OS21-4 John, Lee (1); Jae Gon, Moon (2); Ricky, Madhok (3); Brian, Jankowitz (2); Joseph, Ong (3); Douglas, Kondziolka (4); John C, Flickinger (6); L. Dade, Lunsford (6) (1) Hospital of the University of Pennsylvania - Neurosurgery; (2) University of Pittsburgh Medical Center - Neurosurgery; (3) University of Pittsburgh Medical Center - Department of Neurosurgery; (4) University of Pittsburgh Medical Center - Department of Neurological Surgery Philadelphia, USA Introduction: Stereotactic radiosurgery is the least invasive surgical option for patients with trigeminal neuralgia. It mainly has been used for patients who have failed other procedures. To determine the effect of radiosurgery as the primary surgical management for patients with intractable trigeminal neuralgia, we studied those patients who had radiosurgery without any prior surgical treatments (microvascular decompression or percutaneous rhizotomy). Methods: Over a nine-year period, 480 patients underwent gamma knife radiosurgery for intractable trigeminal neuralgia at the University of Pittsburgh. 211 patients had radiosurgery as first-line treatment. 149 of the 211 patients had over six months of follow-up. Gamma knife radiosurgery was performed using a single 4-mm isocenter targeted to the trigeminal nerve, just proximal to its entry into the brainstem. A median maximum dose of 80 Gy was prescribed (70-90 Gy). The mean follow-up was 37 months (6-109 months). Pain relief was classified into three categories: pain-free with or without medications, partial pain relief (>50%), and little or no relief (<50%). Results: Three months after gamma knife radiosurgery, 87% of 149 patients described themselves as being pain-free. At final follow-up (mean=37 months after gamma knife radiosurgery), 63% of 149 patients described themselves as being pain-free. Eleven percent (23 of 211) of patients developed numbness in the trigeminal distribution. Three percent (6 of 211) of patients devel- oped paresthesia or dysesthesias. No patient developed corneal abrasion or keratitis. Conclusion: Gamma knife radiosurgery is a minimally invasive surgical option for patients with trigeminal neu- ralgia that can be used as a primary surgery for medically refractory patients.
PHYSICS - QUALITY ASSURANCE OS22 Chairmen: Stephan G, Scheib; Frank, Bova Room Permeke & Rembrandt
Using the Winston Lutz test and EPID to compare stereotactic radiosurgery set using Radionics LTLF and BrainLab Target Positioner OS22-1 Robert, Myers (1); Ryan, Smith (1); Michael, Dally (1) (1) The Alfred Hospital - Radiation Oncology Department Melbourne, Australia Using the Winston Lutz test and EPID to compare Stereotactic setup using Radionics LTLF and Brain Lab Target Positioner. Aim : To determine if there is any difference in the accuracy of patient set-up using the Radionics system alone or Radionics couch hardware and Brainscan (by Brainlab) computer generated Target Overlays used in conjunction with BrainLab Target Positioner fitted with printed target overlays. Method: A Rando Phantom with a 6.0mm bearing inserted in the left side of the cranium was set up for stereotactic treatment in the CRW head ring. A CT was per- 173 Oral Presentations Abstracts
formed and sent to the planning system. A spherical volume was placed around the bearing and a rectangular field 24mm square was formed with MLC leaves. The isocenter was positioned cen- trally within the bearing. Three fields were planned, a right lateral, left lateral and anterior. Routine William Buckland Radiothery Center (WBRC) stereotactic Quality Assurance (QA) was done and LTLF set for the isocenter coordinates generated by Brainscan in the usual fashion. The room Lasers were checked against LTLF without any micro adjustment. Films in all 3 projections were taken in 3 planes, as were EPID images. This was repeated after micro adjustment to the set up (micro adjustment positions the planned isocenter at the mechanical isocenter of the machine) was made. The alignment of the isocenter of the Brain Lab target overlays was com- pared to the LTLF isocenter before and after adjustment. Results. There was no discernable differ- ence between the LTLF and the Target Positioner with respect to alignment to the mechanical isocenter of the Linac after micro adjustment. It is the intention to repeat the test a number of times to measure reproducibility of the results.
Assessment of the geometric accuracy in stereotactic PET image definition OS22-2 Josef, Novotny Jr. (1); Karel, Nechvil (2); Josef, Novotny (3); Roman, Liscak (4) (1) Na Homolce Hospital - Medical physics; (2) Na Homolce Hospital - Medical physics; (3) Na Homolce Hospital - Medical physics; (4) Na Homolce Hospital - Stereotactic and radiation neurosurgery Prague, Czech Republic Aim of this study was to evaluate three different techniques used for stereotactic PET image def- inition. A special head phantom with spherically shaped glass test vessel simulating pathologic lesion was used to simulate patient stereotactic imaging procedures. The phantom and test ves- sel were filled with fluoro-deoxy-glucose (18F-FDG) in water solution. Leksell stereotactic MRI indicator box was filled with FDG water solution too. The head phantom underwent subsequent- ly following imaging procedures: 1) PET imaging with MRI stereotactic indicator filled with FDG, 2) PET imaging without any stereotactic indicator, 3) PET/CT imaging with CT stereotactic indica- tor, 4) CT imaging, 5) MRI imaging. All images were transferred into Leksell SurgiPlan software used for stereotactic planning and targetting procedures. Images performed with stereotactic indi- cator were defined according to standard procedures using fiducial markers presented on given image modality. Images without stereotactic indicator were co-registered by Leksell SurgiPlan software subsequently with CT and MRI stereotactic images. Stereotactic X,Y,Z coordinates of the center of the spherical vessel were determined for each PET image definition and compared with CT reference image. Measured deviations in X, Y, Z coordinates were as follows: 1) for PET with stereotactic radioactive markers 0.1±0.3 mm, 0.5±0.4 mm, 1.6±0.7 mm, 2) for PET co-regis- tered to MRI 0.1±0.4 mm, 0.2±0.3 mm, 0.4±0.5 mm and for PET co-registered to CT 0.4±0.4 mm, 0.6±0.5 mm, 0.6±0.6 mm, 3) for PET/CT with stereotactic non-radioactive markers 0.2±0.2 mm, 0.4±0.3 mm, 0.5±0.8 mm. All three evaluated stereotactic PET image definition techniques indicated very good geometric accuracy entirely accepted by clinical requirements.
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Quality assurance in stereotactic imaging using the known target point method OS22-3 Stefan G, Scheib (1); Stefano, Gianolini (2); Nicoletta, Lomax (1); Andreas, Mack (3) (1) Klinik im Park - Gamma Knife Center; (2) Klinik im Park - Department of Medical Radiation Physics; (3) Gamma Knife Center Frankfurt - Medical Physics Zürich, Switzerland Two roughly identical phantoms have been designed to determine known target points based on stereotactic imaging modalities and stereotactic localisation in order to determine the geometri- cal accuracy of stereotactic imaging modalities. Each phantom is made of 8 PMMA plates, which fits by means of a base plate into the Leksell stereotactic frame and is imaged together with the appropriate fiducal marker box in the typical patient set up. The CT/DSA phantom holds 45 steel spheres (diameter = 1 mm) positioned at known Leksell coordinates. The MR phantom holds 21 three dimensional cross hairs. Each cross hair consist of 5 individual glass vials positioned at a known Leksell coordinate. The positions of the phantom markers are known with a precision of better than 0.1 mm. After imaging, the data are imported into LGP where the stereotactic coor- dinates of the visible markers are determined and compared with the known coordinates. Depending on the MR imaging protocol (2D/3D) applied, increased deviations between measured and known coordinates are found near the stereotactic frame. The mean (max) value of the deter- mined deviation is between 0.3 (1.1) and 1.6 (3.6) mm. Dependent on the CT image acquisition (axial/helical) the mean (max) deviation found was between 0.37 (0.73) und 0.75 (1.35) mm. A maximum deviation of 2.5 mm was found in image intensifier based angiographic images, whereas the maximum deviation in plane films was less than 0.5 mm. Special attention must be paid to the geometrical accuracy of stereotactic imaging modalities, because their geometrical uncertainties usually dominate the overall geometrical accuracy of the treatment. The implemen- tation of adequate imaging protocols and quality assurance procedures are a prerequisite for pre- cise lesion targeting. The use of the described phantoms facilitate this task considerably. However, patient related artefacts, leading to geometrical targeting uncertainties cannot be monitored using this method.
Quality assurance in stereotactic radiosurgery according E-DIN 6875-1 OS22-4 Stefan G, Scheib (1); Stefano, Gianolini (2); Nicoletta, Lomax (1) (1) Klinik im Park - Gamma Knife Center; (2) Klinik im Park - Department of Medical Radiation Physics Zürich, Switzerland The E-DIN 6875-1 standard deals with QA criteria and test methods for linear accelerator and gamma knife based stereotactic radiosurgery (SRS)/radiotherapy (SRT). E-DIN 6875-1 covers func- tional performance characteristics, test conditions and test procedures to describe acceptance and regular constancy tests for SRS/SRT therapy systems. The aim of this standard is the comparabil- ity of functional performance characteristics for different irradiation devices for different manufac- turers. This DIN covers dosimetric and geometrical performance characteristics, treatment plan- ning, imaging accuracy and a system test to check the whole chain of uncertainties, from imag- ing through to irradiation based on the unknown target point method. Our existing QA program, based on dedicated phantoms and test procedures, has been refined to fulfil the demands of the new DIN. The radiological and mechanical isocenter correspond within 0.16 mm and the meas- 175 Oral Presentations Abstracts
ured 50 % isodose line is in agreement to within 1 mm. However, significant deviations between the measured and the calculated dose profiles have been found (up to 8 % in the shoulder region for the 8 mm collimator helmet). The measured absorbed dose is within 3 % using various dosimeters. The resultant output factors measured for the 14, 8 and 4 mm collimator helmet were 0.9870 +/- 0.0086, 0.9578 +/- 0.0057 and 0.8741 +/- 0.0202 respectively. For 170 consec- utive system tests using MR imaging the mean geometrical accuracy is 0.48 +/- 0.23 mm. This targeting uncertainty is dominated by the targeting uncertainty of the MR scanner. QA in radio- surgery is labour intensive and time consuming, but an essential basis for a successful clinical out- come. Besides QA phantoms and analysis software developed and tested in house, the use of commercially available dedicated tools facilitates and speeds up the QA according the E-DIN 6875-1 to which our results comply.
ORAL SESSIONS 17h00 - 18h00
FUNCTIONAL - TRIGEMINAL NEURALGIA 2 OS23 Chairmen: Joseph C.T., Chen; Jean, Régis Room Nation
Incidence of paresthesias after radiosurgery (SRS) for trigeminal neuralgia targeting at the root entry zone OS23-1 Alessandra, Gorgulho (1); Antonio, De Salles (2); David, McArthur (3); Zachary, Smith (4); Leonardo, Frighetto (5); Carlos, Mattozo (1); Steve, Lee (6); Michael, Selch (7); Timothy, Solberg (7) (1) UCLA Medical Center - Department of Neurosurgery; (2) UCLA - Neurosurgery; (3) UCLA - Neurosurgery; (4) UCLA - Neurosurgery; (5) UCLA - Neurosurgery; (6) UCLA Medical Center - Department of Radiation Oncology Los Angeles, USA Purpose: Evaluate the incidence and analyze possible correlations for the development of pares- thesias after SRS for Trigeminal Neuralgia (TN). Materials and Methods: From August/1995 to April/2003, 104 patients were treated with SRS for TN, 94 had comprehensive follow-up. Mean age was 64.45±13.25 (29-88) years, 44 female, 50 underwent previous treatment. Sixty-eight (72.34%) had Essential TN, 19 (20.21%) Secondary TN and 9 (9.57%) had Atypical TN. Doses prescribed were: 70Gy (13 patients), 75Gy (5 patients), 80Gy (3 patients), 85 Gy (1 patient), 90Gy (72 patients). Isocenter was placed with the 50% isodoseline (IDL) tangent to the brainstem sur- face. The 5mm collimator was used in 78(82.9%) cases. Results: Paresthesias were observed by subjective report and/or follow-up neurological examination in 50 (53.2%) patients, graded as severe in 3 (3.2%) cases. Good/Excellent outcomes were sustained in 55 (58%) cases at mean 23 months follow-up. Recurrence occurred in 4 cases (5.5-10 months post-SRS). No anesthesia dolorosa or ophthalmologic problems were noticed. TN etiology correlated with paresthesias after SRS (p= 0.02). Paresthesias also correlated with enhancement observed in follow-up MRIs scans (p=0.02), either the nerve or the pons. Patients presenting better pain control did not present a higher rate of paresthesias (p=0.4). No correlation was found between paresthesias and gender (p=0.67), any previous treatment (p=0.67), only previous radiofrequency rhizotomy (p=0.81) or microvascular decompression (p=0.27) or SRS (p=0.24) and prescribed dose (< 90 or 90 Gy) (p=0.4). Conclusions: A higher rate of paresthesias was observed in this series where the isocen- ter was placed closer to the brainstem and a high dose was delivered (90 Gy) for the absolute 176 Oral Presentations Abstracts
majority of the patients. Essential TN and Secondary TN were associated with more paresthesias after SRS than atypical TN. Enhancement noticed in follow-up MRI scans also correlated with paresthesias development. No additional factors correlated with paresthesias occurrence.
Robotized micro-radiosurgery for essential trigeminal neuralgia: Evaluation and analysis of over 100 patients experience with unique method OS23-2 Motohiro, Hayashi (1); Taku, Ochiai (1); Masahiro, Izawa (1); Mikhail, Chernov (1); Koutaro, Nakaya (1); Tomokatsu, Hori (1); Kintomo, Takakura (1) (1) Tokyo Women's Medical University - Department of Neurosurgery Tokyo, Japan Rationale: Gamma knife surgery (GKS) is a minimally invasive treatment for brain diseases, and is currently used for functional disorders. Moreover, refining new Gamma knife system, “Model C-APS (automatic positioning system)” has just been installed since 2002 in Japan. The advan- tage of this system is to provide us to automatically set every coordination with 0.1 mm level adjustment. We’d like to compare between the latest method using APS and the previous one using manual coordination, and evaluate the efficacy and safety of APS treatment for essential trigeminal neuralgia(eTGN). Methods: We have completed a retrospective study of 200 patients suffering from eTGN treated by GKS whose target was localized on the retro-gasserian portion of the nerve. Among the patients, the 152 could be followed up more than 3 months. We assigned into 3 groups according to the term; 1st group(27pts): patients were treated by Model B without completed fusion images (CFI) in between 1999 and 2001, 2nd group(19pts): treated by Model B with CFI in 2002, and 3rd group (104pts): treated by model C-APS with CFI since 2003. Results: Clinical result, initial severe pain(= electric discharge) free was observed in 62.9%(1st group), 85.7%(2nd group), 98.1% (3rd group), complete recurrence was observed in 11.8% (1st group), 5.2 % (2nd group), 0 % (3rd group), and postoperative complication was observed in 14.8% (1st group), 14.3% (2nd group), 9.6% (3rd group). In 3rd group, we found significant difference in between excellent results (rapidly effect without any pain) and fair results (late response with tem- porally recurrence) group, that higher unit energy to the nerve (median: 39.2 vs 33.9 mJ/cc) and lower dose to the Gasserian ganglia (median: 31.9 vs 70.6 Gy) were seen in the excellent group. Conclusions: We suppose, automatically coordinate system with 0.1 mm adustment, so called “Robotized Micoro-Radiosurgery” should be needed to obtain satisfied results. Additionally, in the dose planning, targeting to the nerve should be located on just a little bit more posterior from the trigeminal incisula with “pinpoint” irradiation after adjustment of positional distortion on MRI to provide the patients to relief from severe pain.
Trigemina neuralgia treatment with linear accelerator radiosurgery: results in 82 patients OS23-3 Michael, Girvigian (1); Joseph CT, Chen (2) (1) Kaiser Permanente Medical Center - Department of Radiation Oncology; (2) Kaiser Permanente Medical Center - Neurosurgery Los Angeles, USA Introduction: Radiosurgical treatment for trigeminal neuralgia has been well investigated with gamma-unit device. Few reports exist concerning the treatment of trigeminal neuralgia using lin- 177 Oral Presentations Abstracts
ear accelerator (LINAC)-based devices. In recent years these devices have reached the level of mechanical precision required for such functional treatments. We describe our initial experience with radiosurgical treatment for trigeminal neuralgia employing a BrainLAB Novalis LINAC device. Methods: A total of 82 patients were treated. The median age was 63 years (range 29-88). All patients were BNI grade IV or V prior to treatment. Three cases were complicated by multiple scle- rosis. Patients undergoing initial radiosurgical treatments were treated to the cisternal portion of the trigeminal nerve and received 85 to 90 Gy utilizing a 5 or 7 non-coplanar arc single isocen- ter plan with a 4 mm circular collimator. Cases involving radiosurgical repeat treatment received 60 Gy. Results: Overall good and excellent results (BNI level I, II or III) were obtained in 83%. Median time to pain relief was 4 weeks. Fair and poor results (BNI level IV or V) were seen in 17%. Three patients demonstrated new trigeminal dysfunction following treatment, but in no patient was the corneal reflex lost. No other complications were seen in this series. Responsiveness to anticonvulsant medication was a significant prognostic indicator for treatment success (p<0.05)
Complication of gamma knife surgery for trigeminal neuralgia OS23-4 Shinji, Matsuda (1); Toru, Serizawa (2); Yoshinori, Higuchi (3); Makoto, Sato (4); Junichi, Ono (5) (1) Chiba Cardiovascular Center - Department of Neurology; (2) Chiba Cardiovascular Center - Department of Neurosurgery; (3) Chiba Cardiovascular Center - Department of Neurosurgery; (4) Chiba Cardiovasucular Center - Department of Radiology; (5) Chiba Cardiovascular Center - Department of Neurosurgery Chiba, Japan Object: gamma knife surgery (GKS) is one of effective treatment options for intractable trigeminal neuralgia (TN). Majority of Complications were not severe. However, the incidence of complica- tion in recent reports was higher than that in pervious reports. We reviewed the results of our series and evaluated factors correlated with complications. Methods: Seventy-four medically refractory TN patients were treated with GKS between August 1998 and December 2004. Fifty- three patients received 80Gy at proximal trigeminal nerve root, and 21 received 90Gy at retro- gasserian portion with a single isocenter using 4-mm collimator. Follow-up was obtained by clin- ic visits every three or six months after GKS. Improvement, recurrence, complications and changes in magnetic resonance imaging were recorded. Relations between complication and patient’s characteristics, treatment techniques or pain relief were analyzed with univariate analysis. Results: The follow-up duration was 3-60 (mean 27) months. Forty-six patients showed excellent results (pain free without any medication), 18 patients good (pain free with some medication), 9 patients fair (50% or more decreased in pain), and 1 patient showed poor results (less than 50% improvement in pain). Nine patients suffered from recurrence of neuralgia. Complications were observed in 22 patients at 9 to 36 months after GKS. These patients complained of facial numb- ness, and hypoesthesia was found. Six of them complained their numbness was bothersome. Three of these 6 patients complained of “dry eye” with diminution or absence of corneal reflex. On univariate analysis, patient’s characteristics or treatment techniques were not associated with complications. Satisfactory pain control was significantly related to complications (p=0.003, Fisher’s exact test). Conclusion: In this study, complication was significantly related to good pain control. Trigeminal nerve damage following irradiation is important for both complication and pain control. If both of patients and clinician expect satisfactory pain control, mild numbness would be accepted. 178 Oral Presentations Abstracts
SPINE OS24 Chairmen: Iris, Gibbs; Antonio, DeSalles Room Permeke & Rembrandt
Single fraction spinal radiosurgery for the treatment of spinal metastases OS24-1 Peter, Gerszten (1); Steven, Burton (2); Cihat, Ozhasoglu (3); William, Vogel (3); Annette, Quinn (3); William, Welch (4) (1) Shadyside Hospital - Department of Neurosurgery; (2) Shadyside Hospital - Radiosurgery Department; (3) Shadyside Hospital - Radiation Oncology Department; (4) University of Pittsburgh Medical Center - Department of Neurological Surgery Pittsburgh, USA This study evaluated the effectiveness of radiosurgery for the treatment of spinal metastases. 450 patients were treated with single fraction radiosurgery (mean age 56 years; 206 men; 244 women) (69 cervical, 184 thoracic, 130 lumbar and 67 sacral) using the CyberKnife (Accuray, Inc., Sunnyvale, CA). The most common histologies were renal (n=80), breast (n=68), lung (n=64), colon (n=30) and melanoma (n=30). Three hundred eight lesions received prior external beam irradiation. All dose plans were calculated upon CT images using 1.25 mm slices. PTV was defined as radiographic tumor volume without margin. Radiosurgical circular cones ranged from 5 to 40 mm. Tumor dose was maintained at 12-25 Gy to the 80% isodose line (mean 18 Gy). The maximum intratumoral dose ranged from 15 to 25 Gy (mean 21 Gy). Tumor volume ranged from 0.16 to 298 cc (mean 31.3 cc). The spinal canal volume receiving greater than 8 Gy ranged from 0.0 to 1.7 cc (mean 0.3 cc). No radiation toxicity occurred during follow-up (3-48 months). Axial and/or radicular pain improved in 264 of 290 patients (91%). Twenty-nine of 34 patients (85%) with neurological deficits prior to treatment experienced improvement In the largest series of its kind to date, spinal radiosurgery was found safe and clinically effective for spinal metas- tases. Major potential benefits of radiosurgical ablation of spinal metastases are short treatment time in an outpatient setting with rapid recovery and good symptomatic response. This technique offers an important new alternative therapeutic modality for spinal tumors not amenable to open surgical techniques, in medically inoperable patients, lesions located in previously irradiated sites, or as an adjunct to surgery.
Decade of Cyberknife at Stanford University 1994-2004 OS24-2 Iris, Gibbs (1); Anthony K., Ho (2); Cristian, Cotrutz (3); Steven D., Chang (4); Christopher, King (5); Albert, Koong (6); John R., Adler Jr. (7) (1) Stanford University - Radiation Oncology; (2) Stanford University - Radiation Oncology; (3) Stanford University - Radiation Oncology; (4) Stanford University - Neurosurgery; (5) Stanford University - Department of Radiation Oncology; (6) Stanford University - Radiation Oncology; (7) Stanford University - Neurosurgery Stanford, USA Introduction: Stanford University has a long legacy of contributions to the field of radiation ther- apy. In 1994, the first Cyberknife prototype was introduced at Stanford University Medical Center. Since then, over 1900 lesions have been treated. Here we present a review of these treatments. Methods: We reviewed the records of all patients treated on the Stanford Cyberknife from 1994- 2004. The data are summarized according to type of lesion treated. Trends in the data are shown 179 Oral Presentations Abstracts
graphically and descriptively. Results: Between 1994 and 2004, over 1550 patients with more than 1900 lesions were treated including both intracranial and extracranial lesions. Fewer than 100 lesions were treated 1994-1999. However, by 2003 over 475 lesions were treated annual- ly. Though intracranial lesions constitute the majority of lesions, in the current year nearly one- third of the patients were treated for extracranial lesions. The most rapid rise in extracranial treat- ments was experienced for spine, pancreas, and prostate tumors. We show improved local con- trol in the nasopharynx, good palliation in pancreatic tumors, pain relief for metastatic spinal lesions, control of benign spinal tumors, and feasibility of radiosurgery in the prostate, liver, and recurrent rectal tumors. Conclusion: The Stanford Cyberknife radiosurgery program has been highly successful. We have expanded the flexibility of treating intracranial lesions and pioneered treatments of extracranial lesions of the spine, lung, pancreas, prostate, and liver. The trend toward treatment of extracranial neoplasms has paralleled the improvements dose rate, respira- tory tracking, and image-guidance.
Importance of image fusion for spinal radiosurgery OS24-3 Antonio, De Salles (1); Alessandra, Gorgulho (1); Paul, Medin (2); Nzhde, Agazaryan (3); Timothy, Solberg (3); Carlos, Mattozo (3); Leonardo, Frighetto (3); Cynthia, Cabatan-Awang (3); Michael, Selch (3) (1) UCLA Medical Center - Department of Neurosurgery; (2) UCLA Medical Center - Department of Radiation Oncology Los Angeles, USA Introduction: Dynamics of the spine must be taken in consideration during image acquisition for stereotactic radiation (SR). Materials and Methods: From July/2002 to April/2005, 32 patients were treated with single dose (SRS). There were metastases, neurofibromas, meningiomas and arteriovenous malformation. Lesions were cervical, thoracic and lumbar. Symptoms before SR were pain, paresthesias, weakness or no symptoms. Spine surgery and instrumentation were taken into account for imaging modality of choice. Multiset imaging fusion MRI, CT and Digital Plain films were used to ascertain spine stability and correlation of bone, cord and spinal nerve anatomy during planning and treatment. Patients who received conventional radiation before SRS were also scrutinized for maximal dose to the spinal cord. The dose of choice was 12Gy„b2.7Gy (8-21) prescribed to mean 90% isodoseline (85-97). Intensity Modulation was used when tumor embraced the spinal cord, dynamic multileaf and static beams were also used. Lesion volume var- ied from 0.75-91.8cc. Follow up ranged from 1 to 34 months. Results: Multiset fusion proved invaluable to define tumor and AVM volume and their relationship with structures needing spar- ing. The main symptomatic response was resolution of pain. Weakness improvement was also observed, new neurological deficits related to radiation damage or edema was not observed. Less than 50% of the lesions decreased in size, the majority remained the same and only few metastases progressed when receiving 12 Gy to the periphery of the lesion. Dose to the cord was limited to 8Gy. No complications of shaped-beam and IMRS/IMRT techniques were observed. Conclusions: Multiset imaging fused and visualized simultaneously during planning help ascer- tain spine stability, soft tissue relationships and precision of radiation delivery. The lack of com- plication suggests that higher doses can be delivered to improve the control rate in metastasis patients.
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Image-guided radiosurgery of the spinal nerve: A pilot study in swine OS24-4 Paul, Medin (1); Bryan William, Goss (2); Dennis, Chute (3); Antonio, De Salles (1) (1) UCLA Medical Center - Department of Radiation Oncology; (2) UCLA - Radiation Oncology; (3) UCLA - Pathology Los Angeles, USA Purpose: A pilot study was performed in two Yucatan minipigs to investigate the potential use of a non-invasive, image-guided spinal radiosurgery method to irradiate spinal nerves for the relief of dermatomal pain. Methods and Materials: Mature minipigs (41 kg, 40 weeks old) were used for their anatomical similarities to humans. A CT scan and multiple MRI sequences were acquired and fused for treatment planning. Two consecutive left-sided lumbar spinal nerves were targeted in each animal. ExacTrac infrared tracking and the Novalis Body kilovoltage image guidance sys- tem (BrainLAB, AG) were used for patient positioning. A maximum dose of 90 Gy was delivered to each target using a 5 mm diameter collimator directed through 8 noncoplanar arcs. Behavior and gait were monitored and crude sensory evaluation was performed up to eight months post- radiosurgery. MRI sequences were acquired at the study’s conclusion. Results: Both animals maintained normal behavior and gait throughout the study. One animal became non-responsive to pinching stimulation in its left hind leg four months post radiosurgery. No histological changes were seen in any DRG or spinal cord sections which received maximum doses of approximately 20 Gy and 9 Gy, respectively. Two of the three spinal nerves available for evaluation showed marked changes including a profound loss of myelinated axons and Wallerian degeneration. Conclusions: Axial CISS MRI (0.5 mm) provided the clearest visualization of the spinal nerve. The image guidance technique used is capable of positioning functional targets in the spine. Refinements in imaging and image-guidance may improve targeting. Numbness is a potential side effect of this procedure.
181 Oral Presentations Abstracts
Thursday 15/09/05
PLENARY SESSION 8h45 - 10h00
PS4 Room Nation DATA BLITZ UPDATE 5 Functional radiosurgery PS4-1 Douglas, Kondziolka DATA BLITZ UPDATE 6 Spinal radiosurgery PS4-2 Iris, Gibbs
COMBINED STRATEGIES, TRIGEMINAL NEURALGIA, CANCEROGENESIS Chairmen: Douglas, Kondziolka; Iris, Gibbs
Combination therapy of intentional partial resection followed by gamma knife radiosurgery for large skull base meningiomas PS4-3 Seiji, Fukuoka (1) (1) Nakamura Memorial Hospital - Department of Neurosurgery Sapporo, Japan Objective: The purpose of this study was to evaluate the efficacy of gamma knife radiosurgery (GKRS) when used as a treatment modality for skull base meningiomas (SBMs), with particular attention paid to whether or not a combination therapy of intentional partial resection (IPR) fol- lowed by GKRS constituted an appropriate method for larger SBMs. Method: Of the 101 SBM patients, 38 patients were classified as cavernous sinus meningiomas (CSMs), and 63 with pos- terior fossa meningiomas (PFMs). All patients were treated according to a set protocol. Small to medium sized SBMs (8 CSMs, 49 PFMs) were treated solely by GKRS. To minimize any risk of func- tional deficit, larger tumors were treated by a combination therapy of IPR followed by GKRS (11 CSMs, 8 PFMs). Residual or recurrent tumors in patients who had undergone extirpations prior to GKRS (19 CSMs, 6 PFMs) are not included in this treatment method. Results: The mean follow up period was 51.9 months (6 to 144 months). The tumor control rate was 95.5% in CSMs and 98.4% in PFMs. Almost all tumors treated solely by GKRS were well controlled without any deficits. Furthermore, none of the patients who had undergone prior surgeries experienced any new neurological deficits after GKRS. While newly appearing neurological deficits (total 7) occurred far less in the combination therapy, extirpations tended to be associated with a higher incidence of new deficits or worsening of already existing deficits. Forty six such deficits were identified, only 4 of which showed improvement after GKRS. Conclusion: This study indicates that GKRS can be recommended as a safe and effective treatment of SBMs with small to medium sized tumors. It also demonstrates that larger SBMs can be effectively treated, minimizing any possible functional damage, by this combination therapy. 182 Oral Presentations Abstracts
Incidence of trigeminal nerve dysfunction after trigeminal neuralgia radiosurgery: a comparison between 3 treatment strategies PS4-4 Nicolas, Massager (1); Noriko, Tamura (2); Ouzi, Nissim (3); Daniel, Devriendt (4); Françoise, Desmedt (3); David, Wikler (5); Jacques, Brotchi (1); Marc, Levivier (3); Jean, Regis (6) (1) Hôpital Erasme - Neurochirurgie; (2) CHU La Timone - Gamma Knife center; (3) Hôpital Erasme - Centre Gamme Knife; (4) Institut J. Bordet - Radiothérapie; (5) Hôpital Erasme - PET Scan; (6) CHU La Timone - Service de Neurochirurgie Brussels, Belgium Objective: The aim of this study was to analyze the incidence of facial numbness or dysesthesias following gamma knife radiosurgery (GKR) for trigeminal neuralgia (TN), when 3 different strate- gies of planning are used. Material & Methods: We reviewed the incidence of facial numbness in patients treated for TN in GKR centers of Marseilles and Brussels. In both centers the plexus tri- angularis target was used. For patients with a large perimesencephalic cistern, a maximum dose of 90 Gy was used (group 1, both centers). For patients with a small cistern, to reduce the dose delivered to the brainstem, either the maximum dose was reduced (group 2, Marseilles method), or plugs were used (group 3, Brussels method). We analyzed the mean dose delivered to the trigeminal nerve in those 3 groups. Results: The data of 358 patients were analyzed (group 1: 169 patients (Marseilles=109 +Brussels=60); group 2: 140 patients; group 3: 49 patients). The incidence of trigeminal nerve dysfunction was of 21% in group 1, 7% in group 2 and 49% in group 3. We found a statistically significant relation between induced trigeminal dysfunction and the use of plugs. For each patient, the mean dose and the integrated dose delivered to the trigem- inal nerve were calculated. We found a significant association between incidence of facial hypo/paresthesias and the mean dose delivered to the nerve: average values of the mean dose delivered to the trigeminal nerve were 38.01 Gy for group 1, 32.17 Gy for group 2 and 42.86 Gy for group 3. Conclusion: Use of plugs increases the mean dose delivered to the trigeminal nerve and is associated with an increased incidence of trigeminal nerve dysfunction. To reduce the irradiation of the brainstem during GKR for TN, reduction of the prescription dose seems to be a better option than beam channel blocking.
Estimating the risk of malignancy after radiosurgery in the general population PS4-5 Jeremy, Rowe (1); Alison, Grainger (1); Lee, Walton (2); Aurelia, Kollova (1); Matthias Walter Richard, Radatz (3); Andras A, Kemeny (1) (1) Royal Hallamshire Hospital - National Centre For Stereotactic Radiosurgery; (2) University of Sheffield - Department of Medical Physics and Clinical Engineering; (3) Royal Hallamshire Hospital - Department of Neurosurgery Sheffield, United Kingdom Introduction: To address frequently raised concerns, we attempted a systematic estimate of the risk of intracranial malignancy after stereotactic radiosurgery. Clinical material: From 1985-2004 the Sheffield Unit treated 5014 UK residents. From these, 118 neurofibromatosis patients were excluded. Records were cross-referenced against national mortality and cancer databases. This constitutes over 30,000 completed patient-years of data; 2372 patients having less than 5 years, 1476 patients 5-10 years, 740 patients 10-15 years and 308 patients more than 15 years of fol- 183 Oral Presentations Abstracts
low-up. The mean age at treatment was 45±17 years, there being an equal sex distribution. As a measure of ascertainment, 111 patients with cerebral metastases were treated in this period. Results: Of the 4896 patients, two possible new cases of malignant brain tumour were detected. One was an astrocytoma reported eight years after radiosurgery for a cavernoma. The second possible case was reported in 1994 as a malignant brain tumour, further details are currently being sought. Correcting for age, sex and follow-up, using national cancer incidence figures,[1] we would expect 2.14 cases of central nervous system malignancy to occur spontaneously. In terms of ascertainment, 90% of patients with cerebral metastases were detected by the cross-ref- erencing process. Conclusion With over 30,000 patient-years of data, more than 3,700 years of which was collected after a period of more than 10 years had elapsed since the time of radio- surgery, no excess incidence of intracranial malignancy could be detected. This clearly supports the long-term safety record of gamma knife stereotactic radiosurgery. 1. Cancer Incidences in Five Continents. Ed Parkin DM, Muir CS, Whelan SL, Gao Y-T, Ferlay J, Powell J. International agency for research on cancer. Lyon 1992.
ORAL SESSIONS 10h30 - 11h30
ARTERIOVENOUS MALFORMATIONS 1 OS25 Chairmen: Douglas, Kondziolka; Keisuke, Maruyama Room Nation
Usefulness of time resolved MR digital substracted angiography (MRDSA) in the follow-up of cerebral arterio-venous malformations (AVMs) after gamma knife radiosurgery: preliminary results OS25-1 Philippe, David (1); Patrice, Jissendi (1); Isabelle, Delpierre (1); Danièle, Balériaux (1); Nicolas, Massager (2); Daniel, Devriendt (5); Marc, Levivier (5); Boris, Lubicz (1) (1) Hôpital Erasme - Neuroradiologie; (2) Hôpital Erasme - Centre Gamme Knife Brussels, Belgium Purpose : To evaluate the usefulness of MRDSA in the follow-up of cerebral AVMs treated by gamma knife radiosurgery. Material and methodes: From december 2000 to february 2005, 76 patients were treated by gamma knife surgery for cerebral AVMs. Patient were prospectively fol- lowed at 6,12,18,24 and 36 month by MRI , MRA and MRDSA. When MRDSA concluded to a complete obliteration of the nidus a digital substracted angiography (DSA) was then performed. Results A total of 70 MRDSA allowed to study both size and dynamic evolution of the flow in the nidus. Until now, 14 patients presented a complete obliteration of the nidus on MRDSA. In all those cases DSA confirmed the total obliteration of the nidus. Conclusions : Those prelimary results illustrate the potential usefulness of MRDSA as a non invasive study of both size and flow in AVMs nidus after gamma knife radiosurgery.
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Clinical implications of the latent period after AVM radiosurgery OS25-2 Aurelia, Kollova (1); Farouq, Din (1); Alison, Grainger (1); Jeremy, Rowe (1); Lee, Walton (2); Matthias Walter Richard, Radatz (3); Andras A, Kemeny (1) (1) Royal Hallamshire Hospital - National Centre For Stereotactic Radiosurgery; (2) University of Sheffield - Department of Medical Physics and Clinical Engineering; (3) Royal Hallamshire Hospital - Department of Neurosurgery Sheffield, United Kingdom Introduction: In AVM radiosurgery, it is recognized that there is a latent period before throm- boobliteration occurs and the patient is protected from haemorrhage. To examine this, we reviewed the data of fatal haemorrhages from the database of Office of National Statistics of U.K. that occurred in our patient series. Clinical material: In 2990 treated AVM patients, 93 fatal bleeds were identified. The timing of these events and the radiosurgical and clinical characteristics of the AVMs were reviewed. Results: There was a striking temporal sequence, 48 fatal bleeds (52%) occurring within first two years, 18 bleeds occurring 2-4 years after the treatment and 27 bleeds between 4 and 14 years after radiosurgery. Of the 48 early deaths, 35 had had previous haem- orrhage. We have observed haemorrhages even after complete angiographic conclusion. The AVMs with fatal haemorrhage after radiosurgery were significantly ( p<0.001) larger than our general AVM population treated with radiosurgery: 8.8±8.1ccm compared with 4.8±6.9 ccm. The marginal dose was also significantly less (p<0.01), 22.5±2.7 Gy compared with 23.3±2.7 Gy. Discussion: The majority of fatal rebleeds occur relatively soon after radiosurgery. In our patient series we would however predict over 500 bleeds, given the length of follow-up and average AVM bleed rates. As the observed occlusion rate is less than 90%, this may suggest that radiosurgery provides some protection against haemorrhage, even if there is incomplete angio- graphic obliteration. It is clear, that AVM size is a major adverse factor in determining fatal bleeds, although the other treatment options for such malformations may of course be limited.
The risk of hemorrhage after radiosurgery for cerebral arteriovenous malformations: what is angiographic obliteration? OS25-3 Keisuke, Maruyama (1); Nobutaka, Kawahara (1); Masahiro, Shin (1); Masao, Tago (2); Hiroki, Kurita (3); Akio, Morita (1); Takaaki, Kirino (1) (1) University of Tokyo Hospital - Department of Neurosurgery; (2) University of Tokyo Hospital - Radiology; (3) Kyorin University Hospital - Department of Neurosurgery Tokyo, Japan Background: Angiography shows that stereotactic radiosurgery obliterates most cerebral arteri- ovenous malformations (AVMs) after a latency period of a few years. However, the effect of this procedure on the risk of hemorrhage is poorly understood. Methods: We retrospectively reviewed 500 patients with AVMs who underwent gamma knife radiosurgery. The rates of hemorrhage were assessed during three periods: before radiosurgery, between radiosurgery and angiograph- ic obliteration (latency period), and after angiographic obliteration. Results: Forty-two hemorrhag- es were documented before radiosurgery (median follow-up, 0.4 year) and 23 during the laten- cy period (median follow-up, 2.0 years). Six patients developed hemorrhage after obliteration (median follow-up, 5.4 years). Their histological findings showed occlusion of the AVM by thick- ening of the intimal layer with dense hyalinization as well as a small amount of residual AVM ves- 185 Oral Presentations Abstracts
sels and a tiny vasculature. As compared with the period between diagnosis and radiosurgery, the risk of hemorrhage decreased by 54% during the latency period (hazard ratio, 0.46; 95%CI, 0.26-0.80; P=0.006) and by 88% after obliteration (hazard ratio, 0.12; 95%CI, 0.05-0.29; P < 0.001). The reduction was similar in analyses that took into account the delay in confirming oblit- eration by means of angiography and analyses excluded data obtained during the first year after diagnosis. Conclusions: Radiosurgery significantly decreases the risk of hemorrhage in patients with AVMs, even before angiographic obliteration. The risk of hemorrhage is further reduced, although not eliminated, after obliteration. (NEJM 352:146, 2005 & JNS 102:844, 2005)
Gamma knife radiosurgery as an alterative treatment for dural AV fistulas involving the transverse-sigmoid sinus OS25-4 David Hung-Chi, Pan (1) (1) Taipei Veterans General Hospital - Department of Neurosurgery Taipei, Taiwan A retrospective analysis was performed in 41 patients with DAVFs involving the transverse-sig- moid sinus, who were treated by gamma knife radiosurgery (GKS) alone (24 cases) or combined with surgery and/or embolization (17 cases) between June 1995 and June 2004. The indications for GKS include progressive intolerable headache and bruits, increased intracranial pressure, hem- orrhage and failure of prior treatments. Based on the Cognard’s angiographic classification, there were 13 type I, 13 type IIa, 3 type IIb and 12 type IIa+b. Radiosurgery was performed using multiple (mean 11) shots irradiation to the involved segment of the dural sinus wall in which DAVF nidus located. The margin dose / maximum dose to the nidus ranged from 16.5-20 Gy / 25-36 Gy respectively. Median follow-up was 36 months (range 6-98 months). Of 22 patients who had undergone follow-up angiography, 19(86%) showed complete obliteration of DAVFs, other 3 (14%) showed subtotal or partial obliteration. Symptomatic cure was observed in 71% (29/41) of all patients. There was one complication (2.4%) caused by intracerebral venous hem- orrhage one week after GKS. Other 40 patients experienced smooth and gradually improved clin- ical course. Conclusion: GKS provides a safe and effective therapeutic option for the management of DAVFs. For those DAVFs with mild venous restriction, radiosurgery may be indicated as a pri- mary treatment. However, for some aggressive DAVFs with severe venous reflux and hyperten- sion, initial treatment with embolization or surgery for prompt elimination of aggressive compo- nent of the DAVF is necessary. Radiosurgery may provide an effective djuvant for futher manage- ment of such complex DAVFs.
PITUITARY & CRANIOPHARYNGIOMAS OS26 Chairmen: Ajay, Niranjan; Jeremy, Ganz Room Permeke & Rembrandt
Gamma knife surgery and dopamine agonists in combination in the treatment of the clinical effects of prolactinomas OS26-1 Jeremy, Ganz (1); W A., Reda (1); Ayman, Hafez (1) (1) Cairo Nasser Institute - Gamma Knife Center Cairo, Egypt Objective: gamma knife Surgery (GKS) for prolactinomas remains the subject of controversy. An 186 Oral Presentations Abstracts
attempt is made here to improve and define appropriate treatment measures and to manage these tumours as consistently as possible. This report is an early review of the results obtained in this way. Material and Methods: Fifteen patients with an endocrinopathy. The median follow up is 35 months (range 10 to 44 months). An attempt was made to treat all patients with 35 Gy to the 50% isodose with more than 90% coverage and a conformity index of less than 1.25. The dose to the visual pathway was kept below 8 Gy and this can require decreasing the prescription dose reducing the coverage in some patients. Thus the median prescription dose was 25 Gy (range 12 to 35 Gy). The median percentage cover was 91 (range 66% to 99%). A lower cover was always to avoid damaging the visual pathway. The median target volume was 2.2 cm3 (range 0.2 to 9.7 cm3) The median conformity index was 1.38 (range 1.19 to 2.63). One of 7 acromegalic patients had not been operated. Three of 14 patients with a prolactinoma had not been operated but all three had received dopamine agonists. Results: All patients were kept on dopamine agonists after radiosurgery. No tumour has grown and no visual field has deteriorat- ed. Prolactinomas are treated in combination with a dopamine agonist. In 10 cases the prolactin has normalised and in 2 it is falling. Five of 8 women have had a return of their menstruation. Four of the 7 men have an improvement in potency. In one female patient the prolactin has nor- malised but the periods have not returned. Failure to normalise a hyperprolactinaemia was not associated with dose, tumour volume or duration of follow up. In two patients it may have been due to lack of cooperation with medication. Conclusions: This work suggests that the clinical effects of endocrinopathies can be corrected in a substantial percentage of prolactinomas in a short time if dopamine agonists are not stopped after radiosurgery. Thus, GKS is an acceptable and safe secondary treatment in these conditions. It is suggested the dosimetry described here is crucial for good results. It is further suggested that continuing dopamine agonist treatment may be necessary for a substantial time after radiosurgery if the best clinical result is to be achieved.
Gamma knife radiosurgery for non-functioning pituitary adenomas OS26-2 Hidefumi, Jokura (1); Jun, Kawagishi (1); Hidetoshi, Ikeda (2); Kou, Takahashi (1); Teiji, Tominaga (3) (1) Furukawa Seiryo Hospital - Jiro Suzuki Memorial Gamma House; (2) Tohoku University - Department of Neurosurgery Furukawa, Japan Most of Non-functioning pituitary adenomas show their signs and symptoms by compressing sur- rounding structures like optic nerve and chasm. Immediate surgical decompression must be the choice of treatment in this situation, but complete surgical removal is often impossible when tumor invaded into cavernous sinus. We summarize our result of gamma knife radiosurgery for non-functioning pituitary adenomas after surgical decompression. Sixty-four patients had been treated between Novemer 1991 and March 2003. Twenty-seven were male and 37 were female. Age ranged between 30 to 75 years and the average was 52 years. All but two patients who were old and had medical risks had been operated prior to radiosurgery and in which 22 patients had been operated more than twice. Radiosurgery was performed at the time of recognition of regrowth of tumors in 47 and in 17 patients, immediately after the surgical decompression. Volume of tumor ranged from 0.2 to 21 ml and average was 3.3 ml. Tumor marginal dose ranged from 14 to 30 Gy and the average was 21.1 Gy. Follow up clinical information was available in all cases and MRI images 12 to 145 months after radiosurgery (average 60.5) were obtained all 187 Oral Presentations Abstracts
but 2 patients. During the follow-up, one patient died of parasellar aspergillosis. Surgical removal was needed in 2 patients 7 and 10 years after radiosurgery respectively and the tumor control rate at the last follow up was 97%. We saw no new permanent cranial nerve dysfunction includ- ing optic nerve. During the follow up period, steroid replacement started in one patient who had not been replaced at the time of radiosurgery and one other patient needed thyroid replacement adding to steroid. Gamma knife radiosurgery is very powerful and safe adjuvant for non-funci- tioning pituitary adenomas after adequate surgical removal.
New treatment strategy for craniopharyngioma using Gamma Knife radiosurgery OS26-3 Tatsuya, Kobayashi (1); Yoshimasa, Mori (1); Yoshihisa, Kida (2); Toshinori, Hasegawa (3); Naoki, Hayashi (1) (1) Nagoya Kyoritsu Hospital - Gamma Knife Center; (2) Komaki City Hospital - Department of Neurosurgery Nagoya, Japan The treatment of craniopharyngiomas has been controversial. Total removal is ideal but complete removal without deterioration of neuro-endocrinological functions has been difficult. By the com- bined treatment with partial removal and fractionated radiotherapy, cure or complete control of the tumor has also been difficult and late radiation injury can produce major side effects. Stereotactic radiosurgery has been found to be effective and safe for this tumor. New strategy of treating craniopharyngioma using gamma radiosurgery is needed and presented from our expe- riences of long-term results of 98 cases. The rational observations for a strategy are: 1).Nine-teen (19.4%) of 98 showed complete response (CR), which was stable and unchanged for mean of 75.1 months. 2).The favorable prognostic factors which gave rise to obtain CR by gamma knife radiosurgery were: tumor with adult patient, solid tumor, the mean diameter of 15.9 mm and mean marginal dose of 12.1 Gy. 3).The reduction of the marginal dose resulted in decreased responses and increased tumor progression, although the rate of visual and pituitary function loss also decreased. 4).The common site of residual and recurrent tumor was located at retro-chiasm and ventral stalk area, where should be avoided from total removal. Excellent outcome (cure) can be obtained by gamma knife radiosurgery of relatively small tumors at the retro-chiasm and ven- tral stalk area, using marginal doses of approximately 12 Gy, without neuro-endocrinological deficits.
Biochemical assessment and long-term monitoring in patients managed by radiosurgery for growth hormone secreting pituitary adenomas OS26-4 Ajay, Niranjan (1); Pramod Kumar, Pillai (2); L. Dade, Lunsford (3); Douglas, Kondziolka (3); Sue, Challinor (4); John C, Flickinger (3) (1) University of Pittsburgh Medical Center - Neurological Surgery; (2) University of Pittsburgh Medical Center - Neurological Surgery; (3) University of Pittsburgh Medical Center - Department of Neurological Surgery; (4) University of Pittsburgh Medical Center - Division of Endocrinology and Metabolism Pittsburgh, USA OBJECTIVE: To evaluate the effect of stereotactic radiosurgery on growth hormone (GH) secretion, in patients with newly diagnosed or residual GH secreting pituitary adenomas. METHODS: Twenty-Four patients (10 men, 14 women) who had gamma knife radiosurgery for growth hor- mone secreting pituitary adenoma and were followed at the University of Pittsburgh Medical 188 Oral Presentations Abstracts
Center were evaluated. Nineteen had prior transsphenoidal tumor resection and one had prior radiation therapy. The median tumor volume was 3.0 ml (range 1.2 – 8.4 ml) and the median tumor margin dose was 20 Gy (range 12.5 - 30 Gy) and median central dose was 40 Gy (range, 25-54.5). Median dose to optic apparatus was 6.5 Gy (range, 3-10). Selected beam blocking was used in 6 patients. All patients had serial clinical, radiological, and endocrine assessments. The cure was defined as a growth hormone value of less than 1 ng/ml along with normal IGF-1 (somatomedin C) levels. A complete pituitary hormone profile was requested to assess new hor- mone deficiency. RESULTS: Biochemical cure was achieved in 13 patients (54 %) at a median fol- low-up of 4 years (range, 1-12). Growth hormone and IGF-1 levels were normalized on medica- tion in additional 4 patients (17%) and decreased in seven patients (29%). New hormone defi- ciencies were detected in four patients (17%) one to three years after radiosurgery. No patient reported vision deterioration after radiosurgery. Radiological tumor control was achieved in all 24 patients. CONCLUSIONS: gamma knife radiosurgery is a valuable management option for GH secreting Pituitary adenomas. Regular endocrine follow-up is essential to define cure and detect new pituitary hormone deficiencies.
MOLECULAR IMAGING - PET OS27 Chairmen: David, Wikler; Josef, Novotny Jr. Room Willumsen
Trials to introduce the coordinate system on PET-CT image during dose planning in gamma knife surgery OS27-1 Naoki, Hayashi (1); Yoshimasa, Mori (1); Tatsuya, Kobayashi (1); Yuta, Shibamoto (2) (1) Nagoya Kyoritsu Hospital - Gamma Knife Center; (2) Nagoya City University - Department of Radiology and Radiation Oncology Nagoya, Japan We use magnetic resonance imaging (MRI) and/or computed tomography (CT) for dose planning in gamma knife stereotactic radiosurgery. Positron emission tomography (PET) provides useful additional information as functional image. However, spatial resolution of PET image is not good and voxel size is not fine enough for reference in dose planning of radiosurgery. PET-CT combines multi-slice CT system and PET scanner and generates high quality PET and CT images of a patient in a single study. Two image data sets are registered and fused to form a single image that shows the anatomical location from CT along with the metabolic activity of PET. In some brain tumor cases we take PET-CT with Leksell G-frame and fiducial indicator on the patient head to utilize the same stereotactic coordinate system as that of gamma knife dose planning. Because PET-CT is integrated modality of PET and CT, we can get the coordinates of a certain area on PET by calcu- lating with the fiducials on CT image. We can evaluate findings on PET images precisely with the same coordinates on MRI/CT used for dose planning. This method is useful to evaluate metabol- ic activity of the lesion in detail with coordinate information, especially when the target lesion is small, cystic or heterogeneous, for example, containing necrotic parts.
189 Oral Presentations Abstracts
PET 11C-methionine for gammaknife radiosurgery targeting of recurrent pituitary adenomas OS27-2 Bich-Ngoc-Thanh, Tang (1); Marc, Levivier (2); David, Wikler (1); Mercedes, Heureux (3); Nicolas, Massager (4); Daniel, Devriendt (5); Philippe, David (6); Bernard, Corvilain (4); Serge, Goldman (1) (1) Hôpital Erasme - PET Scan; (2) Hôpital Erasme - Centre Gamme Knife; (3) Hôpital Erasme - Endocrinology; (4) Hôpital Erasme - Neurochirurgie; (5) Institut J. Bordet - Radiothérapie; (6) Hôpital Erasme - Neuroradiologie Brussels, Belgium Purpose: Our purpose was to evaluate whether PET with 11C-methionine (PET-MET) improves the management of recurrent or residual pituitary adenoma (PA), and whether this metabolic infor- mation is a convenient method for guiding gammaknife radiosurgery (GKRS) treatment of PA. Methods: 33 patients with were PA evaluated post-operatively by PET-MET, either because of bio- logical evidence of active residual tumor or because of MRI demonstration of non-functional ade- noma growth. We studied 24 secreting adenomas and 9 non-functional adenomas. Results: In 30 patients, PET-MET detected abnormally hypermetabolic tissue. In 14 out of these, MRI did not differentiate between residual tumor and scar formation. In another group of 16 patients, both PET-MET and MRI detected abnormal tissue. In 1 case, neither MRI nor PET-MET detected PA. Finally, abnormal tissue was detected in 2 patients on MRI solely. Among the initial 33 patients included in the trial, a total of 18 patients were treated by a GKRS procedure planned on the basis of PET-MET and MRI stereotactic integration. Five categories of situations were encountered: i) target volume only defined on PET due to the absence of tumor signal on MRI (G1a; n=4); ii) MRI target initially non detectable, but apparent on PET-MRI co-registration (G1b; n=4); iii) tar- get volume on PET perfectly matches MRI target volume (G2a; n=2); iv) target volumes partial- ly match and consequently adjustments are made to define final therapy target (G2b; n=5); and v) target volume is only defined on MRI (G3; n=3). In our study, the overall success of GKRS was 16/18 89%). Conclusions: We suggest that PET-MET is a sensitive technique for the management of recurrent PA. Because of MRI limitations in detection these tumors, PET-MET provides decisive information to determine target volume in radiosurgical procedures, extending GKRS indications to more difficult cases in terms of lesion detection.
Changes in amino-acid metabolism of pituitary adenomas following GK radiosurgery evaluated by PET-methionine OS27-3 Nicolas, Massager (1); Bich-Ngoc-Thanh, Tang (2); David, Wikler (2); Daniel, Devriendt (3); Françoise, Desmedt (4); Jacques, Brotchi (1); Serge, Goldman (2); Marc, Levivier (5) (1) Hôpital Erasme - Neurochirurgie; (2) Hôpital Erasme - PET Scan; (3) Institut J. Bordet - Radiothérapie; (4) Hôpital Erasme - Centre Gamme Knife Brussels, Belgium Objective: To analyze modifications of the metabolism of methionine of pituitary adenomas (PA) induced by a gamma knife radiosurgery (GKR) procedure. Material & Methods: Between September 2000 and September 2004, 17 patients with a recurrent or residual PA after surgery were treated by GKR in our center using a combination of MR and PET-methionine guidance. There was 3 non-secreting PA, 7 prolactinoma, 6 ACTH-secreting PA and 1 GH-secreting PA. All these patients were followed biologically and by MRI after the GK procedure. A PET-scan with methionine was performed for all patients at 1 year after GKR. We have measured the difference 190 Oral Presentations Abstracts
in methionine metabolism of the PA between the PET-scan performed the day of the GKR and the PET-scan performed 1 year later. We have analyzed the relation between metabolic modification of the PA and biological parameters of the PA and dosimetric parameters of the GKR procedure. Results: Among 17 patients treated, 15 patients (88%) had a favourable biological and MRI-relat- ed outcome. Significant reduction of the metabolism of methionine 1 year after GKR was shown in 14 patients; 3 patients had no assessed modification in the uptake of methionine, including the 2 patients with unfavourable outcome following GKR. Conclusion: A significant reduction in the methionine uptake of PA seems to be related to a favourable biological and MRI-related response to GKR.
Positron emission tomography target segmentation methodology for radiosurgery treatment planning OS27-4 David, Wikler (1); Bich-Ngoc-Thanh, Tang (1); Daniel, Devriendt (2); Marc, Levivier (3); Serge, Goldman (1) (1) Hôpital Erasme - PET Scan; (2) Institut J. Bordet - Radiothérapie; (3) Hôpital Erasme - Centre Gamme Knife Brussels, Belgium The integration in gamma knife radiosurgery treatment planning of Positron Emission Tomography (PET) images is now possible. Our group has assessed in previous studies the clini- cal validity of the accuracy that can be achieved with both frame-based stereotaxic PET and frameless PET. However, in order to take advantage of the PET metabolic information in the spa- tial definition of the lesion, one must be able to accurately delineate the margins of the PET hyper- metabolic signal. As PET does not provide quantitative data and do present a low frequency spec- trum, the segmentation of the lesion boundaries is usually dependent on the sole nuclear physi- cian expertise. We propose a segmentation method based on the lesion average and maximum voxel values ratio. 13 lesions referred to gamma knife for previously untreated brain metastases underwent either stereotaxic (10) or frameless (3) PET Methionine investigation. For each patient, the lesion was segmented by two nuclear physicians according to a fusion with magnetic reso- nance imaging (MRI) T1 with transfer of magnetization contrast agent enhancement. Matching of physicians segmentation results was assessed by a statistically significant linear regression (R2=0.9934). For each lesion, the maximum and the average voxel values in the defined PET vol- umes were recorded. In order to identify whether a segmentation rule could be established out of these parameters, linear regression analysis was performed. A statistically significant (R2=0.9545) linear relationship between the maximum and the average voxel values of a PET Methionine hyper-metabolic volume of interest (VOI) was found (Mean (VOI) = 0.733 x Maximum (VOI) + 677.24). This linear relationship can therefore be used as a mean to automat- ically define the target volume for radiosurgery treatment. In the future, we plan to evaluate the validity of this expression for the delineation of low grade gliomas imaged by PET Methionine.
191 Oral Presentations Abstracts
ORAL SESSIONS 11h30 - 12h30
ARTERIOVENOUS MALFORMATIONS 2 OS28 Chairmen: Serge, Blond; Christer, Linquist Room Nation
Long-term follow-up of quality of life after gamma knife radiosurgery treatment for arteriovenous malformations OS28-1 Michael, Musacchio (1); Brian, Kuchay (1); Nimesh, Patel (1); Bradley, Bagan (1); Sepehr, Sani (1); Demetrius, Lopes (1) (1) Rush University Medical Center - Neurosurgery Chicago, USA Background: gamma knife Radiosurgery (GKR) is a standard treatment modality for intracranial arteriovenous malformations (AVMs). The efficacy and safety of this procedure is well accepted; yet, there is a relative lack of evidence in the literature to support its low morbidity. The goal of this study is to obtain quality of life and complication rate data at long-term follow-up on patients with AVMs treated by GKR. Methods: We independently reviewed 177 GKR procedures per- formed between 1989 and 2001 at a single institution for the treatment of intracranial AVM. Through chart review and direct patient contact, we attained greater than four year follow-up on 40 patients. Clinical outcome was evaluated using a Modified Rankin Scale. Linear regression and Kaplan-Meier survival curves were then employed to analyze the data. Results: Average follow- up was 100 months +/- 52.41 (range 48 to 188.5) with median follow-up of 68 months. Average pre-operative Rankin score was 1 +/- 0.6 (range 0 to 2), compared to average post-op Rankin score of 0.8 +/- 0.7 (p = 0.003). 33 (83%) patients had the same pre and post Rankin score, seven (17%) patients improved, and no patients worsened. Only two (5%) patients expe- rienced major complications requiring surgery for radiation necrosis. Four (10%) others suffered minor transient events including new onset of seizure (n = 2), transient hemifacial paresis (n = 1), and transient visual disturbance (n = 1). No correlation was found between outcome and AVM grade, location, radiation dose, method of presentation, or age of patient. Conclusion: GKR is a safe and effective modality for the treatment of AVM. The immediate impact of treatment on quality of life is minimal. However, we recommend extended follow-up of these patients for sur- veillance of potential long-term complications.
Novalis® based radiosurgical treatment of AVMs. Our pre-eliminary results OS28-2 Recai, Ates (1); Maarten, Moens (1); Katrijn, Van Rompaey (1); Luc, Cavens (1); Cristo, Chaskis (1); Dirk, Vandenberge (2); Jean, D'Haens (1) (1) AZ VUB - Neurochirurgie; (2) AZ VUB - Radiothérapie Brussels, Belgium Introduction: Between May 2000 and August 2003, 43 radiosurgical treatments, using the Novalis® linear accelerator equipped with an adjustable micro-multileaf collimator, were per- formed in a population of 42 patients carrying AVM’s. We report our experience and results of the treatment in 31 patients followed up correctly. Material and methods: The target is deter- mined after fusing MRi with stereotactical CT and biplanar angiographical images. A single dose of 20 Gy, exceptionally lower in giant AVM’s, was given to the margin of a single isocentre. 31 192 Oral Presentations Abstracts
patients, having an angiographical study available 2 years after radiosurgery or earlier if a MRi or CT-angio supposes an occlusion, are included in our study. The mean irradiated volume is 2.38cc. 42% of the AVM’s are located in an eloquent or deep region. We define a patient cured if no angiographical signs of the malformation are left. The slightest residual nidus is enough to define the patient as not cured. In our institution a non-occlusion is seen as definitive if there is no com- plete obliteration after 3 years follow up. Three groups were identified in which we can classify our patients: group1. complete angiographical occlusion, group2. non-occlusion after 3 years, group3. non-occlusion after 2 years, 3th year angiography not yet performed. Results: Group 1 contains 24 patients leading to an occlusion rate of 77.5%. We classify 3 patients in group 2 (9.7%) and 4 patients in group 3 (12.9%). As morbidity, we report two cases of a single epilep- tic insult shortly after radiosurgery and 1 case of temporary local alopecia. Re-bleeding due to incomplete obliteration (a volume of 0.55cc was reduced to 0.07cc) occurred in only one case. Headache was the only symptom from which this patient was suffering. Conclusion: Comparing the literature, our pre-eliminary occlusion rate with the Novalis® is very satisfactory. The proce- dure is very safe with a low morbidity, all temporary.
Clinical outcomes following gamma knife radiosurgery for arteriovenous malformations of the brain OS28-3 Sait, Sirin (1); Kaan, Oysul (2); Hulya, Sirin (2); Asli, Oysul (2); John C, Flickinger (1); Douglas, Kondziolka (1); L. Dade, Lunsford (1) (1) University of Pittsburgh Medical Center - Department of Neurological Surgery; (2) University of Pittsburgh Medical Center - Department of Radiation Oncology Pittsburgh, USA Stereotactic radiosurgery is now a well-accepted approach for patients with selected brain arteri- ovenous malformations (AVMs). We studied a long-term experience with AVM radiosurgery to evaluate clinical outcomes. Between August 1987 and October 2004, 906 patients with AVM underwent one or more stereotactic radiosurgeries. Of these patients, 145 (16%) had multiple procedures either for reirradiation of non-obliterated nidus or prospective staging for large AVMs. Patients presented with an intracranial hemorrhage in 47% and with a seizure in 23%. Two-hun- dred-forty-nine patients (27%) had at least one attempted embolization. The majority of patients (68%) had Spetzler-Martin Grade 3 or higher AVMs. Thalamus, basal ganglia, brainstem, corpus callosum, pineal region and intraventricular locations were seen in 258 patients (28%). The medi- an AVM volume was 3.4 ml (mean 4.83 ml, range 0.065-57.7 ml) and the median margin dose was 20 Gy (range, 13-32 Gy). Out of 602 patients followed more than 24 months, 445 (74%) had total obliteration confirmed either by magnetic resonance imaging (MRI) or angiography. Intracranial hemorrhage after treatment occurred in 38 (4%) patients during the latency period. Cyst formation or encephalomalacia as a late radiation effect was seen in 16 (1.7%) patients, whilst 8 (0.9%) patients developed persistent regions of increased signal on long-TR MRI. No sec- ondary cancer was observed in the follow-up. Analysis of a large group of AVM patients who underwent stereotactic radiosurgery demonstrated that radiosurgery is an effective approach for patients with AVM with an excellent long-term safety profile.
193 Oral Presentations Abstracts
Radiosurgery of cerebral arteriovenous malformations in the paediatric age group. About a series of 100 patients OS28-4 Nicolas, Reyns (1); Serge, Blond (1); G, Touzet (1); B, Coche (1); J.Y., Gauvrit (1); J.P., Pruvo (1); P, Dhellemmes (1) (1) Centre Hospitalier Régional et Universitaire de Lille - Centre Gamma Knife Lille, France OBJECTIVE In order to assess the safety and effectiveness of radiosurgery for arteriovenous mal- formations (AVMs) in the paediatric age group. METHODS We reviewed the data of 100 children (44F/56M) presenting 103 AVMs treated by Linear Accelerator radiosurgery between December 1988 and May 2002. Mean patients age was 12 years old (range 2-16). Around 70% of patients presented intracranial haemorrhage as the first symptom. Sixty seven AVMs (65%) were in func- tional locations and 30% were inoperable. Mean AVMs volume was 2.8 cc (range 0.9-21.3). Mean marginal dose was 23 Gy (range 15-25) requiring 1 to 4 isocenters. 50 patients had mul- timodal treatments with embolization and or surgery before and or after radiosurgery. Since 16 patients had 2 sessions and 1 patient had 3 sessions of radiosurgery, 119 radiosurgical treat- ments were delivered. Clinical and angiographical follow-up were longer than 36 months, unless earlier angiography showed complete disappearance of the AVM. Successive MRI were per- formed to document parenchymal modifications. All AVMs obliterations were confirmed by angiography. Univariate and multivariate analysis were performed to determine predictive factors of obliteration. RESULTS Complete obliteration was achieved in 72 AVMs (70%) with a mean delay to obliteration of 33 months. The morbidity rate was 4.2%, 3 patients presenting a radionecrosis, 1 patient a monocular cecity and 1 patient medically controled seizures. One patient died because of rebleeding. No patient presented bleeding after an angiographycally con- trolled AVM obliteration. Major predictive factors of obliteration were AVMs volume and no prior embolization. CONCLUSION Radiosurgery may be considered as a safety and effective treatment of AVMs in the pediatric age group. Obviously, its role must be discussed in a multidisiplinary approach and regurarly associated to embolization and/or surgery.
Neurological deficit rather than obliteration determines quality of life in patients treated with radiosurgery for AVMs OS28-5 Meera, Ramani (1); Yuri, Souza (2); Deirdre, Dawson (3); Daryl, Scora (4); May, Tsao (5); Michael, Schwartz (6) (1) University of Toronto - Division of Neurosurgery; (2) University of Toronto - Division of Neurosurgery; (3) University of Toronto - Psychology; (4) University of Toronto - Medical Physics; (5) University of Toronto - Radiation Oncology; (6) Sunnybrook Hospital - Neurosurgery Department Toronto, Canada Objective: There is a dearth of literature about the quality of life (QOL) of patients treated for brain arteriovenous malformations (AVMs). This study evaluates the factors that predict the QOL after radiosurgical treatment of patients with AVMs. Method: Between 1989-2000, 228 patients were treated at the University of Toronto using a LINAC system. 181 had a complete radiological and clinical follow-up, including 7 who died. Of the 174 remaining patients, it proved possible to noti- fy 113 by telephone that a three-part questionnaire consisting of questions concerning their neu- rological status before and after treatment and a Medical Outcomes Study questionnaire (SF-36) would be sent. Results: Of the 113 forms sent, 66 (58.4%) were adequately completed and returned. There were no significant differences in age, AVM location and volume between patients who returned the questionnaires, patients who didn’t return the questionnaires, and 194 Oral Presentations Abstracts
patients who could not be contacted. However, patients who returned the questionnaires had a higher rate of permanent deficit (10.6% vs. 8.1% and 4.4%) and a lower obliteration rate (54.2% vs. 68.8% and 70.3%) than those who didn’t return the questionnaires, and those who could not be contacted, respectively. In a multivariate analysis, the most important predictor of quality of life was permanent deficit. In order of importance, permanent deficit affected the various aspects of QOL as follows: role physical, physical functioning, social functioning and vitality (P= 0.000, 0.006, 0.040, 0.049, respectively). AVM obliteration was not a predictor of QOL, even for the emotional scales. Conclusion: Permanent deficits were associated with a lower quality of life and this should be considered a strong end-point in the choice among treatment modalities. Surprisingly, AVM obliteration was not a predictor of the quality of life for these patients.
EXTRACRANIAL RADIOSURGERY 2 OS29 Chairmen: Morten, Hoyer; Gabriela, Simonova Room Permeke & Rembrandt
Stereotactic radiosurgery after external radiotherapy for nasopharynx carcinoma OS29-1 Selcuk, Peker (1); Beste Melek, Atasoy (2); Meric, Sengoz (2); Ufuk, Abacioglu (2); Turker, Kilic (1); Necmettin, Pamir (1) (1) Marmara University School of Medicine - Department of Neurosurgery; (2) Marmara University - Radiation Oncology Istanbul, Turkey The aim of this study is to evaluate the efficacy of gamma knife radiosurgery on nasopharynx car- cinoma which had external radiotherapy. There were 10 patients (6 male, 4 female) in this series. The median age of the patients was 56. Gamma knife radiosurgery was performed as a boost in 4 patients, and for recurrent disease in the others. Median dose to the periphery of the tumor was 11 Gy (7-20 Gy). In 7 patients the local control of the tumor was achieved. One patient was died due to the local invasion of the tumor. 2 patients were died due to the distant metastasis. One year survival rate was found to be 33% (median 12 months) and local growth control rate was 75%. Gamma knife radiosurgery seem to be partly effective on local growth control of nasopharynx carcinoma.
Image guided conformation arc radiosurgery for prostate cancer: early clinical results OS29-2 Guy, Soete (1); Dirk, Verellen (2) (1) AZ VUB - Radiothérapie; (2) AZ VUB - Physique Brussels, Belgium Purpose: To evaluate clinical results in prostate cancer patients treated with image guided confor- mation arc radiosurgery using a minimultileaf collimator and daily X-ray assisted patient position- ing. Methods and Materials: Between May 2000 and November 2004, 238 cT1-T3N0M0 tumors were treated. Isocenter dose was 70 or 78 Gy, depending on the risk group the patient belonged to. Seventy patients in addition received neoadjuvant and/or concurrent hormonal treatment. Median follow-up is 18 months (range: 4-55 months). Acute side effects were scored using the RTOG/EORTC criteria. Late side effects were assessed using a modified ("clinical") SOMA scale. The 195 Oral Presentations Abstracts
ASTRO consensus definition was used to define biochemical failure. Freedom from late toxicity and biochemical control were calculated with the Kaplan-Meier method. Results: Grade 1, 2 and >2 acute side effects occurred in 19, 6 and 0% (gastrointestinal) and 37, 16 and 0% (genitouri- nary) of the patients. No relation between radiation dose and early side effects was observed. Four-year freedom from ¡_ grade 2 late GI side effects was 98.9%. Four-year freedom from ¡_ grade 2 late GU side effects was 99.2%. Four-year freedom from biochemical failure was 95.2%. Conclusion: Patients treated with image guided conformation arc radiosurgery experience a low rate of grade 2 (i.e. requiring medication) early side effects. The evaluation of late side effects and biochemical control requires further follow-up.
PET predicts treatment failure of extracranial stereotactic radiosurgery before CT OS29-3 Volker W., Stieber (1); William, Kearns (1); William, Hinson (1) (1) Wake Forest University School of Medicine - Department of Radiation Oncology Winston Salem, USA Purpose/Objectives: Extracranial Stereotactic Radiosurgery delivers a single inhomogenous dose to a lesion in the body. We present the imaging results of a subgroup of patients who underwent PET imaging on an ongoing Phase I/II study. Materials/Methods: Eligibility criteria included a well- circumscribed malignant tumor with a maximum diameter of 6 cm. Patients had to be age >= 18 years with a life expectancy >= 3 months. No chemotherapy was allowed 3 weeks prior to or planned for 4 weeks after treatment. The Primary Endpoints were acute toxicity using NCI Common Toxicity Criteria 3.0 (Phase I) and local control by CT RECIST (PD/SD/PR/CR) criteria (Phase II). Results: 28 patients have so far been enrolled. Two dose escalations have been com- pleted. 12 (43%) patients have undergone PET imaging. For this group, median follow-up so far is 377 days. Median survival has not yet been reached. 3 deaths have occurred. For these 3 patients, median survival from time of treatment was 250 days. Local control at 3 months was 100 %. The median change in tumor diameter at 3 months was -14% for a median RECIST = SD. The median corrected SUV change at 3 months was -57%. At last follow-up, 8 patients have had no PD. For 7/8, the SUV decreased and had not increased by the last follow-up. 4 patients have had PD by RECIST. 3/4 had a corresponding rise in correct SUV, which preceded the RECIST progression by a median of 71 days. The median time to RECIST failure for these patients was 238 days. Overall, the correlation between RECIST control and PET control was 0.71. Discussion: In the late phase, (> 3 months) PET progression appears to precede RECIST PD by 2.4 months. This may have implications for the initiation of subsequent therapy (e.g. chemotherapy).
How can tumor effect and normal tissue effect be balanced in stereotactic body radiotherapy OS29-4 Wolfgang, Tome (1); John, Fenwick (1); Jack, Fowler (1); Minesh, Mehta (1) (1) University of Wisconsin Medical School - Human Oncology Department Madison , USA Methods for selection of an appropriate dose fractionation schedule for stereotactic body radio- therapy that has both an equivalent tumor effect for lesions of varying size and at the same time ensures an acceptable risk of clinically manifest radiation pneumonitis have not been adequately addressed. We have developed a model-based methodology for selection of an appropriate dose 196 Oral Presentations Abstracts
fractionation schedule for radioablation of peripheral T1/T2 N0 M0 lung tumors that lets one achieve a progression free survival at 30 months of larger or equal to 80% while keeping the inci- dence of significant radiation pneumonitis below 20%. Because of the short schedules used in SBRT, accelerated repopulation is not a concern and therefore a schedule that has a BED10 ≥ 100 Gy10 is projected to achieve greater than 80% of progression free survival at 30 months. Our modeling shows that in order to keep the mean normalized total dose to the residual healthy lung (both lungs – PTV) below 19Gy3, the dose at which the risk of pneumonitis would be acceptable, the selection of a dose fractionation schedule depends on both the ratio of the Prescription Isodose Volume (PIV) to the residual healthy lung volume and the late local damage BED3 associated with this fractionation schedule within the PIV one is willing to tolerate for a tar- geted 30 month progression free survival of 80% or higher. The model, its background, and clin- ical implementation will be discussed.
IMAGING 2 OS30 Chairmen: John, Flickinger; Michael, McDermott Room Willumsen
How much does the addition of stereotactic T2 images affect tumor definition and treatment plans for acoustic schwannoma radiosurgery? OS30-1 John, Flickinger (1); Douglas, Kondziolka (2); Ajay, Niranjan (3); Ann H., Maitz (4); L. Dade, Lunsford (2) (1) University of Pittsburgh Medical Center - Department of Radiation Oncology; (2) University of Pittsburgh Medical Center - Department of Neurological Surgery; (3) University of Pittsburgh Medical Center - Neurological Surgery; (4) University of Pittsburgh Medical Center - Image Guided Neurosurgery Pittsburgh, USA Objective: We sought to assess the effect of using stereotactic T2 imaging in addition standard T1 contrast-enhanced images to define the contours of acoustic schwannomas for radiosurgery. Methods: After completion of gamma knife radiosurgery to ten unilateral acoustic schwanno- mas,.tumor contours were drawn first using T1 contrast-enhanced images alone, and a second time using T1 and T2 images. This process was repeated two more times to create three pairs of images using T1 alone versus T1 plus T2 images. The contours of the cochlea and vestibule were drawn using T2 images. Four tumors were purely intracanalicular and six extended into the cere- bellar pontine angle. Prescription doses varied from 12-13 Gy (12.5 Gy in 7/10) to the 50-60 % isodose (median 50%) using 3-9 isocenters (median 6). We created inverse treatment plans with- out manual adjustments from contours drawn for T1 images alone versus T1 plus T2 imaging for an unbiased assessment of the effects on the treatment plan and doses to the cochlea and vestibule. Results: In all cases, we reduced tumor volumes from T1 images alone after reviewing T2 images. Volume reductions occurred at the lateral tip of the tumor close to the cochlea and at interphases with blood vessels and meninges. The median volume reductions and % reductions for the intracanalicular schwannomas were 7.3 mm3 (range: 5-25.6) and 6.7 % (3.4-13.6), com- pared to 19.1 mm3 (12.3-39.9) and 3.7 % (1.2-8.7) for the extracanalicular tumors. Planning tar- get volumes were smaller with T2 imaging in 7/10 cases for a median difference of 5.0 % (range: -7.7 to 28.1 %). T2 imaging lead to reductions in mean cochlear dose in 9/10 patients as well as maximum cochlear, mean and maximum doses to the vestibule in 8/10 patients (p=0.060, 0.033, 0.052, 0.095 paired t-tests respectively, with mean dose reductions of 25, 18, 35, and 25 197 Oral Presentations Abstracts
% respectively) . Conclusion: Adding T2 imaging to standard T1 stereotactic imaging for acoustic schwannoma radiosurgery results in a reduction in treatment volume that results in a decreased dose to inner ear structures in the vast majority of cases.
A CT scan and anatomical cadaveric study of the pterygopalatine ganglion for use in gamma knife treatment of cluster headache OS30-2 William, Olivero (1); Jorge, Alvernia (2); Dan, Spomar (3) (1) OSF Saint Francis Medical Center - Department of Neurosurgery; (2) University of Illinois - Neurosurgery; (3) University of Illinois - Neurosurgery Peoria, USA Objectives: Gamma knife radiosurgery is used to treat patients with Cluster Headaches. Both the trigeminal root and the pterygopalatine ganglion(PPG) have been targeted. However, there are no clear-cut anatomical landmarks on CT scan or MRI that accurately identify the PPG. Therefore, we performed microsurgical dissections on injected cadaver heads to expose the PPG and corre- lated the findings with thin slice axial CT scans with 3D reconstruction on the same heads to determine how best to target the PPG. Methods: Three cadaver heads(5 sides) previously inject- ed with colored latex were dissected in order to identify the PPG and surrounding structures. Then measurements to different bony landmarks such as the foramen rotundum, vidian canal etc. were made. The PPG was marked with a radiopaque marker then thin slice CT scans performed on the cadaver heads to attempt to develop some CT correlates that could be used to identify where the PPG is located on CT scan. Results: The PPG was clearly identified in all specimens with an aver- age diameter of 3.58 mm +/-0.6mm. The PPG was always located in the same plane (lat and vertical) as the vidian canal and was on average 2.7 mm anterior to the end of the canal. The vidian canal was clearly identified on the coronal reconstructed CT scan with a diameter of 3.05mm. Conclusion: There was a constant relationship between the PPG and vidian canal. The vidian canal is easily identified on coronal reconstructed CT scan and can be used as a landmark to target the PPG with gamma knife.
Assessment of post-radiosurgical imaging studies: a volumetric algorithm and an estimation of its error OS30-3 Jason, Sheehan (1); John, Snell (2); Matei, Stroila (3); Ladislau, Steiner (1) (1) University of Virginia - Department of Neurosurgery; (2) University of Virginia - Lars Leksell Center for Gamma Knife Radiosurgery; (3) University of Virginia - neurosurgery Charlottesville, USA Objective: The gamma knife is playing an increasingly important role in the treatment of neuro- surgical patients. The goal of the tool is not necessarily to totally obliterate a tumor but to induce its control. During planning, dose-volume histograms require accurate volumetric analysis of the lesion. Also, accurate follow-up volumetric analysis is important to compare to the lesion volume at the time of radiosurgery . Methods: The accuracy of the estimation of volume or volume change of anatomical structures as they appear in medical imagery is limited by a number of error sources. We consider the sampling geometry of tomographic modalities and its contribution to volumetric error through a simulation framework. In addition to providing empirical bounds on volumetric error, this approach provides a tool for guiding the specification of imaging protocols 198 Oral Presentations Abstracts
when a specific volumetric accuracy, or volume change sensitivity, for particular structures is sought a priori. Results: Using computational geometry techniques, the error associated with vol- umetry was shown to be dependent upon the number of slices through the region of interest and lesion volume. With a minimum of five slices through the region of interest, the volume of a lesion between 0.1 to 15 cc could be computed accurately with less than a 10% error. When fewer than 5 tomographic slices through the region of interest were obtained, then the potential difference between the actual and computed volume increased substantially. Conclusions: These volumet- ric tools are particularly relevant for radiosurgical treatment planning and follow-up analysis. Through the application of this volumetric methodology and a better understanding of the error associated with it, a more accurate assessment of the treatment result is probable.
Meningiomas after radiosurgery: When is recurrence expectable? OS30-4 Roberto, Spiegelmann (1); Janna, Menhel (2); Rafael, Pfeffer (2); Dror, Alezra (2) (1) Sheba Medical Center - Department of Neurosurgery; (2) Sheba Medical Center - Department of Oncology Ramat Gan, Israel During a 12-year period 312 meningiomas at different locations were treated with LINAC radio- surgery at our center. 55 tumors with less than 2 y follow up were discarded. 6 patients died early after treatment, 3 had surgery due to radiation injury. 59 patients did not have adequate follow- up (19%). 189 patients had follow-ups ranging from 24 to 144 months (mean 54/median 48 months). Recurrence defined as persistent growth of more than 20% of the original volume was observed in 11 tumors (5.8%). All of them occurred between 15-48 months after treatment. No tumor growth was observed in 75 patients followed for 5 years or more (mean 81 months/medi- an 72 months). Volume reduction was observed in 117 tumors (62%) overall. Tumor shrinkage incidence tend to increase over time (48% at 2 years, 60% at 3 years, 72% at 5 years, 54% at 6-8 years, and 78% at 9-12 years). While recurrence of meningiomas after conventional surgery peaks at 3-4 years, it may be observed at random even 2 decades after surgery. Recurrence after radiosurgery as per this series was only observed during the first 4 years following treatment.
199 200 Posters Abstracts
Monday 12/09/05
POSTER SESSION 1 10h30 - 11h30
GENERAL, EXTRACRANIAL RADIOSURGERY, VESTIBULAR SCHWANNOMAS, ARTERIOVENOUS MALFORMATIONS, METASTASES, GLIOMAS, RADIOBIOLOGY, MEDICAL IMAGING, PROTON THERAPY
Clinical and radiobiological advantages of stereotactic light ion beam radiation therapy for large intracranial arteriovenous malformations P1-1 Bahram, Andisheh (1); Bengt, Lind (1); Mohammadali, Bitaraf (2); Panayiotis, Mavroidis (1); Anders, Brahme (1) (1) Karolinska Institutet - Department of Medical Radiation Physics; (2) Iran Medical Science Of University, Ali Asghar Hospital - Iran Gamma Knife Center Stockholm, Sweden Objective: The special characteristics of high linear energy transfer (LET) light ion beams offer sev- eral advantages over photon and proton beams for single dose stereotactic radiation therapy of intracranial arteriovenous malformations (AVMs). These include more favorable depth dose-dis- tribution in tissue, almost negligible lateral scattering, a sharper penumbra as well as a steep dose fall-off beyond the Bragg peak. A comparison between different radiation modalities has been made with the effectiveness of Bragg peak radiosurgery. These features include higher flex- ibility in designing optimal treatment plans for intracranial lesions, so that critical structures, could be avoided. Methods and Materials: Dose Volume Histograms (DVHs) and peripheral doses for large AVMs from different centers were collected and dose-response parameters derived by a maximum likelihood fitting of the Binomial model to these data. The present Binomial model quantitates the effective number of crucial vessels such as feeding arteries in AVM. Results: A bet- ter angiographic obliteration rate as well as lower complication rate and lower white matter necrosis for stereotactic radiosurgery with heavy charged particles was observed which followed with more favorable clinical outcome. For larger AVMs a higher number of effective vessels was predicted which complies with the fact that a large AVM typically has more compartments with more feeding arteries and draining veins. Conclusion: The better dose distribution of Ion beams and the dose homogeneity in the target volume is an advantage over conventional photon radi- ation modalities. The unique physical and biological characteristics of light ion beams are of con- siderable advantage for the treatment of large AVMs. Bragg peak radiation therapy has been rec- ommended for most large and irregular AVMs and for the treatment of lesions located in front of or adjacent to sensitive and functionally important brain structures. The binomial model based on the effective number of crucial vessels in the AVM predicts AVM obliteration probability for small and large AVMs quite well both for photon and light ions.
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Gamma knife radiosurgery for cerebral arteriovenous malformation P1-2 Maheep Singh, Gaur (1) (1) VIMHANS Complex - Department of Gamma Knife Radiosurgery New Delhi, India Introduction: Aim of the study is to assess efficacy of gamma knife Radiosurgery for management of cerebral Arteriovenous malformation as single primary modality. Method: We have treated 148 patients with cerebral arteriovenous malformation between April 1998 and April 2005. Of these 123 patients were followed for a year or more. No patient was operated and 5 patients had par- tial emoblization elsewhere. Forty seven patients had AVMs located deep or in eloquent areas. Sixty one [50%] patients presented with hemorrhage, 48 [39%] with seizures and rest 13 [11%] were incidental or with other deficit. Mean Treatment volume was 6.86cc [0.1-49.2]. None of the patients were advised emobilization or surgery irrespective of size or location. Mean prescription does was 22.07 Gy covering 99.42% [94-100] treatment volume, with a mean prescription iso- dose of 47.48% [40-60] . Mean dose at maximum was 46.59 Gy [30-65.5]. Results: Twenty-six percent patients obliterated in first year, 53.6 %in 1.5 years, and 12.4% by the end of second year. Over all 92% obliteration by the end of two years. Two patients had bleed and died. Two patients develop cyct formation at 2 year and 3-year follow up Conclusion: Gamma knife radiosurgery can be adopted as primary treatment for cerebral Arteriovenous malformation without emobilization
Management and outcomes of hemorrhage for cerebral arteriovenous malformations treated with radiosurgery P1-3 Tomoyuki, Kouga (1); Keisuke, Maruyama (1); Masahiro, Shin (1); Hiroki, Kurita (2); Nobutaka, Kawahara (1); Akio, Morita (1); Takaaki, Kirino (1) (1) University of Tokyo Hospital - Department of Neurosurgery; (2) Kyorin University Hospital - Department of Neurosurgery Tokyo, Japan OBJECTIVE: Appropriate management of hemorrhage after radiosurgery for cerebral arteriovenous malformations (AVMs) is poorly understood. METHODS: Among 467 patients followed for 1 to 154 months (median 69 months) after radiosurgery, 32 patients suffered a hemorrhage. Hemorrhage developed even after angiographic obliteration in 5 (2.1%) out of 239 patients fol- lowed at a median of 75 months post-obliteration. They had been treated according to their pathological condition. Management results of them and their outcomes were retrospectively reviewed. RESULTS: As a management for pre-obliteration hemorrhage, intracerebral hematoma along with an AVM nidus was removed in four patients, and chronic encapsulated hematoma was removed in three. Among 11 patients conservatively managed, AVMs were finally obliterat- ed in five, including three who received repeated radiosurgery. Intracerebral hematoma from angiographically obliterated AVMs was radically resected in two patients, including one who also underwent an aspiration of accompanying symptomatic cyst. Intraoperative bleeding was easily controlled in these patients. Outcomes after hemorrhage measured with modified Rankin scale scores was significantly better in patients with post-obliteration hemorrhage than those with pre- obliteration hemorrhage (P<0.05). CONCLUSION: Various types of hemorrhagic complications after radiosurgery for AVMs could properly be managed by understanding each pathological con- dition. Although a small risk of bleeding remains after obliteration, surgery for such AVMs was 202 Poster Abstracts
safe, and their outcomes were more favorable. Radical surgical resection to prevent further hem- orrhage is recommended for ruptured AVMs after obliteration, because such AVMs can cause repeated hemorrhages.
Follow-up to cure of intracranial arteriovenous malformations after gamma knife radiosurgery P1-4 Michael, Musacchio (1); Brian, Kuchay (1); Nimesh, Patel (1); Sepehr, Sani (1); Demetrius, Lopes (1) (1) Rush University Medical Center - Neurosurgery Chicago, USA Background: Gamma knife radiosurgery (GKR) is a well accepted treatment modality for intracra- nial arteriovenous malformations (AVMs) based on the excellent results and low morbidity asso- ciated with this procedure. In particular, stereotactic radiosurgery is of primary importance in the treatment of AVMs located in deep or eloquent brain, as well as in AVMs of high Spetzler-Martin grade. Reports in the literature, however, on nidus obliteration rates after GKR vary significantly. The goal of this study is to analyze factors associated with angiographic cure of AVM after GKR. Methods: We performed an independent review of 177 GKR procedures done over a period of 11 years at a single institution for the treatment of intracranial AVM. Only 109 charts were avail- able to us for review, and we selected only those patients who had angiographic follow-up for analysis. Angiographic follow-up was performed on 67 patients at a range of 11 to 138 months (median was 23mos.). The remainder of the patients were followed with CT, MRI, or no imaging at all. AVM cure was defined as angiographic confirmation of complete nidus obliteration. We constructed a Kaplan-Meier survival cure to analyze the probability of AVM cure as a function of time. Using logistic regression, we evaluated multiple factors as indicators of AVM cure including clinical presentation, AVM location, AVM grade, pre-operative imaging used for dose planning, maximum radiation dose, peripheral radiation dose, number of shots delivered, and patient age at time of GKR. Results: AVM cure was determined on angiography in 43 (65%) of the 67 patients with adequate follow-up in this series. Median time to angiographic cure was 26.5 months (range 11 to 38 mos.). Patients chosen for GKR therapy of their AVM were found to be well-select- ed against surgical intervention as evidenced by a high percentage of AVMs located in eloquent brain (73%) and median Spetzler-Martin grade of 3 at presentation. The Spetzler-Martin grade distribution was as follows: I-3(5%), II-11(16%), III-27(40%), IV-16(24%), V-3(5%), indetermi- nate-7(10%). We constructed a Kaplan-Meier survival cure to plot angiographic cure of AVM and found that the probability of AVM cure in patient’s who had follow-up angiography approaches 90% over extended follow-up. Although many factors contribute to treatment modality selection in patients with AVM, we found no correlation between probability of AVM cure and clinical pres- entation, location, grade, dose, imaging used for dose planning or age of the patient at time of GKR. Only dose delivered to the periphery of the target approached marginal significance (p=0.11). Conclusions: We conclude that the probability of AVM nidus obliteration in our popu- lation of patients who had angiographic follow-up after treatment of high grade AVMs located primarily in eloquent brain tissue is superior to obliteration rates associated with other treatment modalities given similar grade and location of AVM. Furthermore, the length of clinical follow-up correlated to angiographic follow-up achieved in this study speaks for the durability of GKR in the treatment of AVM. We found no influence of patient condition at presentation, location and grade of AVM, level of dose delivered or patient age at time of GKR on cure rate of AVM after GKR. Raza Shaan 203 Poster Abstracts
Fractionated stereotactic radiosurgery for large intracranial arteriovenous malformations P1-5 Shaan, Raza (1); Quoc-Anh, Thai (1); Salma, Jabbour (2); Gustavo, Pradilla (1); Lawrence, Kleinberg (3); Moody, Wharam (3); Daniele, Rigamonti (1) (1) Johns Hopkins University School of Medicine - Department of Neurosurgery; (2) The Johns Hopkins University School of Medicine - Department of Radiation Oncology and Molecular Radiation Sciences Baltimore, USA OBJECTIVE: The treatment of high grade (Spetzler-Martin III-V) arteriovenous malformations (AVM) remains a challenge. There is a paucity of literature addressing the efficacy of radiosurgery in the management of this group. We review our experience with fractionated radiosurgery of large intracranial AVMs. METHODS: Between 1989 and 2004, 15 patients with large AVMs deemed to be non-operative candidates were treated with fractionated radiosurgery. Patients were treated either on a LINAC or gamma knife based system at 2-3 year intervals. Treatment doses were chosen based on Flickinger graphs predicting the chance of symptomatic radiation necrosis, or the volume receiving 12 Gy or more for a particular location in the brain. Patients who did not receive their full treatment course or follow-up at the institution were excluded. RESULTS: The complete obliteration rate was 33% while the remaining 66% experienced partial response (Mean volume reduction 53%). Mean follow-up was 18 months. Twenty percent of grade III and 50% of grade IV experienced cure. Treatment complications included: two post-treatment hem- orrhages (2 patients), persistent headaches (2 patients). One patient died as a result of hemor- rhage. No statistical difference was noted between the obliterated and partially obliterated groups with regards to mean pre-treatment volume (24.87 cm3), median Spetzler-Martin grade (IV), mean follow-up, total delivered dose (3550 cGy), mean dose/fraction (13 Gy), median num- ber of fractions (2) or mean interval between treatment fractions (40 months). CONCLUSION: The present study demonstrates the potential role of fractionated radiosurgery in the treatment of this cohort when compared to the published data in the context of our short follow-up. The benefits of staged therapy could be derived from using lower doses per session and staged targeting of the lesion in an effort to increase response and decrease complication rates. It is evident that staged stereotactic radiosurgery could be employed in the treatment of large intracranial AVMs in the framework of a multimodality approach with surgery and embolization.
Fractionated stereotactic radiotherapy in residual or recurrent nasopharyngeal carcinoma P1-6 Mantana, Dhanachai (1); Puangtong, Kraiphibul (1); Lucksana, Pochanugool (1); Somjai, Dangprasert (1); Putipun, Puataweepong (1); Ladawan, Narkwong (1); Jiraporn, Laothamatas (1); Boonchu, Kulapraditharom (2); Veerasak, Theerapancharoen (3); Ekaphop, Sirachainan (4); Pornpan, Yongvithisatid (1); Prasert, Assavaprathuangkul (1) (1) Ramathibodi Hospital Mahidol University - Department of Radiology; (2) Ramathibodi Hospital Mahidol University - ENT; (3) Ramathibodi Hospital Mahidol University - Department of Surgery; (4) Ramathibodi Hospital Mahidol University - Medicine Bangkok, Thailand Purpose: To evaluate results of fractionated stereotactic radiotherapy (FSRT) in patients with resid- ual or recurrent nasopharyngeal carcinoma (NPC) in terms of local progression-free and overall survival rate and complications after treatment Methods: From August 1998-March 2004 there 204 Poster Abstracts
were 32 residual or recurrent NPC patients treated with FSRT using linac-based radiosurgery sys- tem. Time from the previous radiotherapy to FSRT was 1-165 (median,15) months. Two patients were treated for the second and one for the third recurrence. Thirteen patients also received chemotherapy with FSRT. Tumor volume ranged from 6.2-215 (median,44.4) cc. Average FSRT dose was 17-59.4 (median,34.6) Gy in 4-25 (median,6) fractions in 1-5.5 (median,3) weeks. Results: Follow up time ranged from 3-56 (median,21) months. Local progression-free survival rate at 1 and 3 years after FSRT was 67.4% and 31.4%. Overall survival rate at 1 and 3 years was 89.1% and 70.3%. If all patients who were lost to follow up were assumed death the over- all survival rate at 1 and 3 years would be 73.8% and 39.4%. Eight patients had complications after FSRT (more trismus in 4, decreased hearing in 4, transient ischemic brain symptoms in 1, dysphagia and hoarseness in 1, and headache in 1). Conclusion: FSRT was useful for patients with residual or recurrent NPC and was well tolerated.
Linac radiosurgery in extracerebral head and neck lesions P1-7 Miron, Sramka (1); Augustin, Durkovsky (2); Arpad, Viola (3); Yaroslav, Parpaley (1); Peter, Strmen (4) (1) St. Elisabeth Cancer Institute - Department of Radiosurgery; (2) St. Elisabeth Cancer Institute - Department of Radiology; (3) St. John's Hospital Budapest, Hungary - Department of Neurosurgery; (4) Comenius University hospital - Department of ophtalmology Bratislava, Slovakia Purpose: Malignant eye melanomas are one of difficult topics of contemporary ophthalmology. Using of mini- invasive radiosurgery opens new perspectives for treatment of patients with absolute or partial contraindications for surgery or brachyterapy.Advantage of the treatment by Linac in comparison with gamma knife is in better ability to focus on marginal areas. Since 1992 we have operated 627 patients with Linac . 25 patients of them had extracerebral cranial lesions. Methods: We have selected patients with malignant uveal melanoma, who had tumor elevatiuon more than 8 mm or the localization on posterior retina. Eye fixation was made by ophthalmogist through extraocular muscles by stitches, direct eye muscles at stereotactic frame to have the eye in the same position during MRI and CT examination and radiation. Low set of stereotactic frame gives possibility to treat extracerebral lesions like chemodectomas under skull base to treat extrac- erebral lesions like chemodectomas under skull base to level C3 with radiosurgery. Results: We operated 16 patients with uveal melanoma and 10 patients with chemodectomas. Two patients had combination of intracranial and extracranial lesions, which were operated together in the same time. Therapeutic dose at margin of the tumor was 35 and 38 Gy for melanomas and 16 – 18 Gy for chemodectomas. Complications after stereotactic radiosurgery like cataract and secondary glau- coma are possible. Conclusions: Long term results show us, that radiosurgery is an effective method of treatment of eye uveal melanoma and is comparable with brachyterapy , gamma knife or proton beam therapy or as a first step procedure before intravitreal endoresection. Our experi- ence shows that linac radiosurgery is an effective method for treatment of extracerebral cranial lesions and enables treatment of pathological lesions of neck eye and maxilofacial area.
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Endocavitary irradiation of glioma cysts with 90-Yttrium colloid solution P1-9 Arpad, Viola (1); Jeno, Julow (1); Balint, Katalin (2); Istvan, Nyary (3) (1) St. John's Hospital Budapest, Hungary - Department of Neurosurgery; (2) National Institute of Neurosurgery, Budapest, Hungary - Department of Pathology; (3) National Institute of Neurosurgery, Budapest, Hungary - Department of Neurosurgery Budapest, Hungary Objective: To evaluate the role of stereotactic endocavitary irradiation of glioma cysts, we retro- spectively reviewed our experience with 17 patients (8 female, 9 male). Methods: All 17 patients had one or more CT or MR imaging guided, stereotactic cyst endocavitary 90 Yttrium colloid irra- diation. Eight patients had low grade and 9 patients had high grade gliomas. The mean cyst vol- ume was 40 cm3 (4.8 – 115). The cysts’ wall dose ranged from 300 Gy to 350 Gy. Results: In the immediate postoperative period, 12 out of the 17 (70 %) patients experienced symptomatic improvement. No procedure-related morbidity was encountered. In high-grade gliomas the ben- efit of possible shrinkage and/or disappearance of the cyst was vanished by solid tumor progres- sion. In low grade gliomas more than 50 % of the cysts disappeared and 25 % of them shrunk- en up to one third of starting volume. Conclusion: The low surgical invasiveness, the absence of severe side effects and good therapeutic results induce us to propose this as a primary treatment in inoperable expanding cysts of gliomas.
Specific nurse attendance during routine Leksell Gama Knife radiosurgery in children P1-10 Elisabeth, Rioz Galvez (1); Benoit, Pirotte (2); Patricia, Palacio (1); Arlette, Dewil (1); Philippe, David (3); Daniel, Devriendt (4); Françoise, Desmedt (5); Michel, Baurain (6); Jacques, Brotchi (2); Marc, Levivier (7) (1) Hôpital Erasme - Centre Gamme Knife; (2) Hôpital Erasme - Neurochirurgie; (3) Hôpital Erasme - Neuroradiologie; (4) Institut J. Bordet - Radiothérapie; (5) Hôpital Erasme - Centre Gamme Knife; (6) Hôpital Erasme - Anaesthesiology Brussels, Belgium Objective. To define the characteristics of the nurse attendance specific to Leksell Gamma-Knife radiosurgery (LGK) in children. Methods. In the 2000-2005 period, a total of 1033 LGK procedures were performed at Erasme Hospital, Brussels, Belgium. Among them, 24 were performed in chil- dren (9 females and 15 males; aged 6 < 5 years; 9 between 5 and 10 years; 9 > 10 years). The underlying disease was either an arterio-venous malformation (n=8) or an intracranial tumor (n=16) (3 ependymomas, 3 pilocytic astrocytomas, 3 glioblastomas, 2 choroid plexus carcinomas, 2 schwanomas, 1 craniopharyngioma, 1 meningioma, 1 hamartoma). All radiosurgical procedures used the LGK model C and were based on combined Computed Tomography (CT) and Magnetic Resonance (MR) imaging. Positron Emission Tomography (PET) images were performed in 8 chil- dren with tumors and were combined to MR images in the dosimetry planning according to a methodology described elsewhere. The characteristics of the nurse attendance specific to children were studied. Conclusions. In all cases, the PET/CT/MR/selective angiography images were acquired in frame-based stereotactic conditions on the same day as the radiosurgical procedure. All procedures were performed under general anesthesia (GA) with the attendance of a senior anaesthesiologist. The main characteristics specific to LGK treatment in children appeared to be the long duration of the GA (from 6 to 8 hours), especially in PET-guided procedures and the 206 Poster Abstracts
potential devastating morbidity from patient’s inaccurate positioning during long-lasting GA. All potential sources of complications due to the positioning and to the technical devices (imaging, therapeutic and anesthetic) were checked systematically. Inaccurate positioning might generate prolonged compression of numerous structures and cause: 1) ischemic (cutaneous); 2) hemody- namic (low cardiac outflow, increased venous pressure); 3) traumatic (tendinous elongation, cer- vical spine subluxation) lesions. Hypothermia should not be underestimated. A practical check-list for routine use by the nurse team is presented. This study emphasized the important routine role of the nurse team for avoiding morbidity which is not acceptable nowadays.
Gamma knife radiosurgery in pediatric population. Early Mexican experience P1-11 Daniel Salvador, Ruiz Gonzalez (1); Ramiro, Del Valle (1); Salvador, De Anda Ponce de Leon (1); Miguel, Perez Pastenes (1); Juan, Ortiz Retana (1); Manuel, Martinez Lopez (1); Josue, Estrada (1) (1) Medica Sur SA de CV MSU 820125 T58 - Unidad Gamma Knife Mexico, Mexico Radiosurgery is a highly technified stereotactic procedure that applies a single session of ionizing radiation guiding its effect to a target I specify sparing the normal adjacent structures. This pro- cedure is used frequently to treat different types from cerebral diseases. The indications for its use have been increasing with the passage of time, initially the main indication was the treatment of vascular malformation, at the moment is indicated to treat different types of benign and malig- nant tumor and functional pathology. Initially Radiosurgery was used in adult patients, later Atschuler et al. (1989) published their clinical experience with radiosurgery in the pediatric pop- ulation. The outcomes are related to the specific disease. As we know the conventional radiother- apy produce important side effects mainly on neurocognitive function, the more severe the younger is the patient. Also as we know the side effects of the radiotherapy appear between 2 – 3 years after the treatment. In the present work we showed our early experience and results in the pediatrics patients treated with gamma knife radiosurgery for benign and malignant tumors, vascular and functional disease.
Stereotactic radiosurgery for benign brain tumors - A single institution experience P1-12 George, Pissakas (1); V, Georgolopoulou (2); M, Kalogeridou (3); E, Andriotis (4); K, Doukaki (3); S, Kosmidou (3); S, Mourgela (5); G, Arhontakis (7); E, Pappas (2); V, Kouloulias (6); I, Kouvaris (10); A, Sotiropoulou (3) (1) ALEXANDRA Athens General Hospital - Radiation Oncology; (2) St.Savvas Hospital - Medical Physics; (3) St.Savvas Hospital - Radiation Oncology; (4) St.Savvas Hospital - Radiology; (5) St.Savvas Hospital - Neurosurgery; (6) University of Athens - Radiation Oncology Athens, Greece Purpose/Objective: Stereotactic radiosurgery (SRS) is applied for the treatment of specific intracra- nial lesions in an increasing number of centers worldwide. A linac-based radiosurgery program is implemented in our hospital since 2000. The current study presents our experience from using SRS to treat patients with acoustic neuromas and meningiomas. Materials/Methods: SRS treatments are applied in our hospital using a 6 MV linac beam, a floorstand isocentric subsystem attached to the linac gantry, circular collimators and a dedicated workstation for image fusion and treat- ment planning. Patients having received treatment for benign tumors in the interval between May 207 Poster Abstracts
2000 and October 2003, were 17 acoustic neuroma cases (14% males, 76% females, age range: 50 to 80 years, median 64, lesion size range: 0.78-15 cc, median: 6.0) and 14 with meningioma lesions (30% males, 70% females, age range: 35-83 years, median: 65, lesion size range from 3.1 to 12 cc, median: 6.1). Neuromas were treated with a surface dose of 11-13 Gy using single or multiple isocentres depending on their shape (median maximum tumor dose: 22.5 Gy). The dose given to the surface of the meningiomas ranged from 14 to 17.5 Gy with 1-6 isocenters depending on the shape of the lesion (median maximum tumor dose: 23.7 Gy). Results: In the acoustic neuroma patient group follow up times range from 5 to 45 months (median: 21). MRI/CT images of the treated area taken 6 months and yearly after treatment show local control in all patients. From the 15 patients that have completed follow up times longer than one year, none has shown tumor growth, central necrosis is seen in ten cases and lesion reduction in three. Hearing preservation was not an issue as all patients selected to undergo treatment suffered from loss of hearing. In one patient facial weakness appeared 13 months after treatment. The follow up times in the meningioma patient group range from 11 to 39 months (median: 25). Imaging of the treated area indicates local control for all patients. For two patients a reduction in tumor size is observed one year after treatment. One patient suffered from transient facial weakness 10 months after treatment. Conclusion: These relatively early results are comparable to published results from centers with longer follow up times and larger patient series and support the evidence that radiosurgery is a useful therapeutic technique for the treatment of benign brain tumors.
Gamma knife radiosurgery for skull base tumors - Complications and outcome P1-13 Sujoy, Sanyal (1); Sandeep, Vaishya (2); Aditya, Gupta (2); S S, Kale (2); V S, Mehta (2) (1) All India Institute of Medical Sciences - Neurosurgery Department; (2) All India Institute of Medical Sciences - Neurosurgery Department Calcutta, India Introduction Gamma-knife-radiosurgery has become popular for skull-base-tumors because it yields good functional preservation of the patient. Our objective was to evaluate complications and outcome following radiosurgery for skull-base-tumors with a relatively low 12-Gy margin- dose (except for glomus-tumors). Materials and methods We treated 129 acoustic-neuromas (including 11 NF-2 patients), 119 skull-base-meningiomas, 21 5th-nerve and 14 lower-cranial- nerve(LCN)-neurofibromas with a mean volume of 4.5-cc, with a 12-Gy median margin-dose generally prescribed to the 50%-isodose volume. Multiple isocentres were used to ensure confor- mal planning. We also treated 8 glomus-jugulare-tumors with a mean volume of 12.65-cc, with 12-20 Gy to the tumor-periphery (mean margin-dose of 15.6-Gy). Results We have a median clin- ical-follow-up of 25.6-months. Among 33 acoustic-neuromas with pre-gamma-knife functional- hearing, 2 improved, 4 deteriorated while 27 remained same yielding a hearing-preservation-rate of 88%. The hearing-preservation-rate among NF-2-patients was 50% only. Among skull-base- meningiomas, only one had hearing deterioration with facial paresis. Hearing was preserved among all patients of glomus and 5th/LCN-neurofibromas. Among acoustic-neuromas, only one case each of trigeminal and transient-LCN-dysfunction (due to perilesional-edema) was observed. Two patients with sphenoid-wing-meningiomas developed trigeminal-neuralgia. Three patients of 5th–nerve-neurofibromas had improved facial-sensation while one developed 3rd-nerve palsy and another developed gait-ataxia due to perilesional-cerebellar-edema. Careful planning 208 Poster Abstracts
ensured no visual complications. One acoustic-neuroma-associated-cyst recurrently increased leading to ataxia and trigeminal-neuralgia requiring repeated cyst-tapping. Hydrocephalus devel- oped/worsened in 3 skull-base-meningiomas. Radiological-follow-up is available at a median of 26-months. Among the non-NF-2 acoustic-neuromas, 9 decreased, 2 increased, and 34 remained stable. Among 10-NF2 patients, 2 had one-sided-increase, 1 had one-sided-decrease while 7 had stable tumor-size yielding a tumor- growth-control-rate of 80% in NF-2-patients and 95% in non- NF2-patients. Among skull-base-meningiomas, 2 increased (surgery revealed a malignant-menin- gioma and a hemangiopericytoma), 10 decreased while 50 remained stable yielding a tumor- growth-control-rate of 97%. Among 5th /LCN-neurofibromas, 4 decreased, 14 remained same while 1 increased yielding a tumor-growth-control-rate of 95%. Among glomus-tumors, two receiving 12-Gy and 18-Gy to the tumor-periphery decreased while 2 receiving 15-Gy and 18-Gy remained same. One tumor treated primarily as a fifth-nerve-neurofibroma increased and was operated revealing a mesenchymal-chondrosarcoma. Another treated primarily as a cavernous- sinus-meningioma developed multiple lesions suggestive of metastases. This exposes an inher- ent drawback of primary gamma-knife-radiosurgery based on imaging diagnosis. Conclusions Cranial-nerve preservation following radiosurgery has undergone a quantum jump with the adoption of MR-based multiple-isocentric lower-dose conformal-planning. However improved functional outcome using a 12Gy margin-dose needs long-term analysis to ensure good tumor- control although preliminary results seem encouraging. As for glomus-jugulare-tumors, more analysis is needed for arriving at a suitable treatment-dose.
Image guided micro radiosurgery for brain tumors to avoid underlining dysfunction of the surrounding vital structure: technical note P1-16 Motohiro, Hayashi (1); Jean, Regis (2); Taku, Ochiai (1); Koutaro, Nakaya (1); Mikhail, Chernov (1); Masahiro, Izawa (1); Tomokatsu, Hori (1); Kintomo, Takakura (1) (1) Tokyo Women's Medical University - Department of Neurosurgery; (2) CHU La Timone - Service de Neurochirurgie Tokyo, Japan Rationale: gamma knife surgery is one of “Image guided surgery” for brain tumors. Precisely tumor visualization should be needed to complete dose planning to control tumor progeression. In particular, the surrounding vital structures also should be defined more clearly for the tumors which were adjacent to them to keep their underlining function. Recently, we selected the spe- cial sequence of MRI dedicated to skull base and suprasellar tumors. We’d like to report the use- fulness technical point of view and evaluate clinically. Method and Results: Normally, we are using high quality of MRI and CT for tumor radiosurgery. For skull base and suprasellar tumors, additionally, we prefer to use dedicated sequence, “3D heavily T2WI axial 0.5mm thickness with gadolinium enhancement” according to Timone university method (supervised by prof REGIS). Each structure which was adjacent to the tumor could be visualized more clearly than that with- out gadolinium, because tumor became lucid on the MRI without change the findings of sur- rounding structures after injection of gadolinium. For acoustic tumors, we could visualize 5th, 7th, and 8th nerves in not only cisternal portion but also intrameatal portion, which could be distin- guished the tumor. For cavernous sinus tumors, we could visualize optic nerve, pituitary gland, lateral wall of the sinus, and the other nerves which were located in the cistern which also could 209 Poster Abstracts
be distinguished the tumor. And for suprasellar tumors, we could completely distinguish between tumor and adjacent optic pathway. Finally, we could perform optimal dose planning in every tumor to keep highly conformity and selectivity to keep their underlining function. Conclusions: We demonstrate to establish optimal dose planning for brain tumors with dedicated special sequence of MRI. In the nearest future, we hope that most majority of patients who are treated by Gamma knife will experience no complaint of new neurological deterioration and overcome their still existed neurological deficit.
Preliminary experience with MMLC at the INNN in Mexico City. 804 patients treated in a singular facility P1-17 Miguel Angel, Celis-Lopez (1); Jose, Suarez-Campos (1); Sergio, Moreno (1); Leopoldo, Herrera (1); Jose M, Larraga (1); Amanda, Garcia G (1); Mariana, Hernandez B (1) (1) National Institute of Neurology and Neurosurgery - Radioneurosurgery Mexico City, Mexico INTRODUCTION: We present preliminary results of the first radiosurgical LINAC exclusively dedi- cated for neurosurgical diseases. This is a the first Novalis (BrainLab, Inc) coupled with a 3T MRI (GE) for novel imaging planning with this system, furthermore every patient was evaluated and socioeconomic considerations were made in the case of a financial assistace was needed. METH- ODS:The treatment planning was performed with Brain Scan V.5.2 (BrainLab,Inc,2002) based on CT imaging with head frame for single fraction or a mask for fractionated radiotherapy, image fusion with 3T MRI (angio-MRI or Conventional angio for AVM`s)Treatment delivery was per- formed with the Novalis micromultileaf system (m3-mMLC (R) by statis conformal beams, dynam- ic arcs or Intensity Modulated Radiation Surgery Therapy (IMRS/IMRT)RESULTS:From decembeer 2002 to april 2005 a total of 804 patients were treated. Ages ranged from 2 to 77 years old. were Pathologieswere benign tumors 429 (53%), gliomas 143 (18%), vascular 136 (17%) Funcional 31 (4%)A team of social workers evaluated the social conditions of every patient in order to give support to those patients with special needs. In this way a large recuitment was obtained in a short period of time. CONCLUSIONS: This a preliminary experience and longer fol- low up in neccesary .
The use of tissue equivalent Super Stuff Bolus (TM) material to treat skull metastases with gamma knife radiosurgery P1-18 Lilyana, Angelov (1); Gennady, Neyman (2); Gene H, Barnett (3); Betty, Jamison (4); John H., Suh (5); Lilyana, Angelov (6) (1) Cleveland Clinic Foundation - Department of Neurosurgery; (2) Cleveland Clinic Foundation - Department of Radiation Oncology; (3) Cleveland Clinic Foundation - Brain Tumor Institute; (4) Cleveland Clinic Foundation - Brain Tumor Institute; (5) Cleveland Clinic Foundation - Gamma Knife Center; (6) Cleveland Clinic Foundation - Brain Tumor Institute Cleveland, USA Introduction: Gamma Plan(TM) software is known to inaccurately calculate surface dose as its computation algorithm does not take into account the surface build-up region. This can lead to gross underdosing of the skin and near surface regions of the head. We present a novel approach to the treatment of skull metastases within 5 mm of the scalp surface using gamma knife radio- surgery. Method: A patient with a history of a T1N0M0 adenocarcinoma of the lung, metastatic 210 Poster Abstracts
to the brain status post whole brain radiation therapy, presented 3 years later with a solitary occipital calvarial lesion and no other evidence of systemic disease. Since the lesion was very superficial, we decided to use tissue equivalent Super Stuff Bolus(TM) material applied to the affected calvarial area to prevent underdosing. The problem of immobilizing the bolus material was effectively solved with the use of a snug fitting elasticized swimming cap. Results: The Super Stuff Bolus(TM) material could be effective molded to the patient’s head and held in place with the swimming cap. The Leksell frame was placed, pinning through the bathing cap. The patient tolerated the bolus material and bathing cap well during the entire treatment and the radiosurgi- cal treatment proceeded in the standard manner. These measures allowed for improved accuracy in the planning and delivery of the treatment. The accuracy was confirmed using the Lucy(TM) 3D+ Universal QA Phantom and direct experimental measurement of surface dosing with and without tissue equivalent surface buildup. Preliminary results using the QA Phantom suggest that without the use of Super Stuff Bolus Material(TM) superficial lesions can be underdosed as much as 50%. Conclusion: Our study shows that Super Stuff Bolus(TM) material immobilized with a bathing cap allows for an innovative, simple and more accurate treatment of very superficial lesions using gamma knife radiosurgery.
Magnetic resonance image distortion: a phantom study with varying parameters for stereotactic radiosurgery P1-19 Sawwanee, Asavaphatiboon (1); Ladawan, Worapruekjaru (2); Jiraporn, Laothamatas (2); Pornpan, Yongvithisatid (2); Wiboon, Suriyajakyuthana (2); Lojana, Tuntiyatorn (2); Mantana, Dhanachai (2) (1) Ramathibodi Hospital Mahidol University - Radiology; (2) Ramathibodi Hospital Mahidol University - Department of Radiology Bangkok, Thailand MR image distortion is one of the main factors, affecting the accuracy of stereotactic target local- ization. Image distortions result from inhomogeneity of the main magnetic field, non-linearity of magnetic gradients and eddy current effects, the severity of which depends on the type of pulse sequence and parameters. Therefore, we assessed the image distortions of the cylindrical phan- tom with three techniques, SE, FSE and 3DFSPGR seqyences, providing T1W contrast; with vary- ing parameters (TR, TE, phase encoding, bandwidth and NEX) using a 1.5T magnet (GE Medical system, USA). Using computed tomographic data as the reference standard, the studies showed that the greatest distortion was found around the periphery zone especially in 3DFSPGR at the position +60mm from the center and the least distortion was present in the middle zone. In all techniques, when the slice position was far from the center (Position=0), the image distortion will be greater. The maximal values of the displacement in the periphery zone when using SE, FSE, and 3DFSPGR were 1.5 mm (range,0-1.5mm), 1mm(range,0-1mm) and 2mm(range,0-2mm) respectively while the maximal values of the displacement in the middle zone, when using Spin- echo(SE), Fast- spin echo(FSE), and 3D spoil Gradient echo(3DFSPGR) were 0.5 mm (range,0- 0.5mm), 0.5mm(range,0-0.5mm) and 1mm(range,0-1mm), respectively. For all parameters, bandwidth is a single parameter affecting image distortion. We conclude that for all techniques, the accuracy of target localization for SRS can be achieved within the center of the image. The image distortion will be decreased by increasing bandwidth.
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The use of T2 weighted MRI for post gamma knife follow-ups P1-20 Joel Y. C., Cheung (1); C.P., Yu (1); Robert TK, Ho (1) (1) Canossa Hospital - Gamma Knife Centre Hong Kong, Hong Kong Introduction: The blood-brain barrier prevents low-life forms (such as toxins) that make it into the blood stream from tainting the brain's pristine nerve cell habitat. However, the blood-brain barrier of normal brain tissues close to the treated tumour may break down after gamma knife surgery. Therefore, some abnormal contrast enhancement surrounding the treated tumour may appear on T1 weighted MR images with contrast injection. An apparent increase of tumour volume in post gamma knife follow-up MR scans may result. Methodology: A T2 weighted MR scan without con- trast injection before a routine T1 weight MR scan with contrast injection was done with the same FOV for the post gamma knife follow-ups. There must be no re-centring of slides between the T2 and the T1 scans. Therefore, the coordinate relationship between these two scans was maintained. A coordinate system was assigned for these two MR scans by using the non-fiducial based tech- nique (Cheung et al 1998). A mapping using GammaPlan v3.x on the T2 slides could be project- ed on the T1 slides. Discussion and Conclusions: The projection of the mapping of an selected gamma knife follow-up patient showed discrepancy between the T2 and the T1 images. The dis- crepancy was due to the abnormal contrast enhancement surrounding the treated tumour on the T1 MR images. The contrast enhancement was explained by the breaking down of blood-brain barrier after gamma knife surgery. We suggested that it always performs the T2 weighted MR scan without contrast injection for the post gamma knife follow-ups, in order to provide an additional information. Reference: Cheung Y. C. Joel, Yu C. P., Ho T. K. Robert, Tweaked GammaPlan for tar- get volume measurement in non-fiducial based images: a simple routine for follow up assessment, Stereotactic & Functional Neurosurgery, Vol. 70, Suppl. 1, 1998, pp. 243-248.
Effects of fiducial marker defects in image registration P1-21 Hyun-Tai, Chung (1); Dong Gyu, Kim (1) (1) Seoul National University Hospital - Department of Neurosurgery Seoul, Republic of Korea Introduction: Defects in fiducial markers in stereotactic radiosurgery images are usually ignored in image registration procedure. The authors assessed the effects of defects in fiducial markers using a software generated virtual phantom method. Methods: Virtual phantom images with six fidu- cial markers of Leksell G-frame® were generated using IDL® v6.0. A virtual phantom consisted of 81 slices of thickness 1.0mm(z=-40.0 to 40.0). Image resolution was 256x256 and field of view was 256mm. Each slice had six fiducial markers in square shape with length 3.0mm. In addition to fiducial markers, the phantom had three slices which had nine check points at z=30.0, 0.0, and -30.0, respectively. These 27 points were used to measure the errors in posi- tion calculation. Several types of defects in fiducial markers were generated in three consecutive slices and images were registrated using Leksell Gamma Plan® v5.40. The errors in fiducial mark- er registration and in position calculation of the check points were evaluated. Results: The maxi- mum errors in image registration varied from 0.2mm to 1.4mm depending on type of defects in fiducial markers while the mean error were 0.1mm. The error was most severe when only small part of a fiducial marker was included in registration. Virtual phantoms with missing fiducial mark- 212 Poster Abstracts
ers had less error than phantoms with deformed markers. When images with deformed markers were excluded, the resulting error was same with phantoms with missing markers. Ordinary mean errors in position of check points was 0.1+/-0.1mm. The image set with largest image reg- istration error showed 0.2+/-0.1mm error in position calculation. Conclusion: The image regis- tration was affected by defects in fiducial markers. The effect was most severe when only small portion of fiducial markers (largest defects) were included. Though resulting error in position measurement is small, it is better to exclude images with defective fiducial markers in image reg- istration process.
The impact of different ways of image definition on the z-position of the target P1-22 Andreas, Mack (1); Stefan, Scheib (2); Marcus, Rieker (3); Dirk, Weltz (4); Robert, Wolff (5); Hans-Jürg, Kreiner (6); Volker, Seifert (7); Heinz, D., Böttcher (8) (1) Gamma Knife Center Frankfurt - Medical Physics; (2) Klinik im Park - Medical Radiation Physics; (3) PTGR- GmbH - Software Development; (4) PTGR-GmbH - Software Development; (5) Gamma Knife Center Frankfurt - Neurosurgery; (6) GKS-GmbH - Management; (7) Johann Wolfgang Goethe University - Neurosurgery; (8) Johann Wolfgang Goethe University - Radiotherapy Frankfurt, Germany Purpose/Introduction: Given the high mechanical accuracy of the Leksell gamma knife, the most sensitive technical factor having an influence on the overall precision of radiosurgery is the imag- ing (mainly MRI) study. When checking the accuracy of the 3D-sequence with dedicated phantoms we observed inconsistencies when defining the images in different ways. Material and Methods: Different phantoms and patient studies were used to evaluate this phenomenon. A cylindrical phantom with an embedded equidistant grid was used as well as a known target phantom with embedded cross vials at known geometrical positions related to the stereotactic coordinate sys- tem of the Leksell frame. Automatic and manual defintion (at different positions of the image stack) were performed. Further on a independent software was used to analyze the images. Results: Different ways of defining images lead to different z-values of the images within the stack. Deviations up to 5 mm can be observed for the representations of images of the upper skull (low z-values). By defining the image stack manually in the upper region of the image stack, this shift can be reduced. In spite of superior resolution and contrast we have to keep in mind that due to physical aspects (z-gradients, volume exciting direction, etc.) the 3D-sequences are much more sensitive to potential z-shifts than the corresponding 2D-sequences. For the treatment of multiple metastases it is recommended to check the defined targets with a 2D-sequence or CT.
Hypofractionated stereotactic radiotherapy for lung tumors P1-23 Antje, Ernst-Stecken (1); Ulrike, Lambrecht (1); Rolf, Sauer (1); Oliver, Ganslandt (1); Gerhard, Grabenbauer (1) (1) Novalis Shaped Beam Surgery Center, University Hospital of Erlangen, Germany - Radiation Oncology Erlangen, Germany Purpose/Objective: Given the possibility of highly conformal dose application, extracranial stereo- tactic radiotherapy (eSRT) offers radiation dose escalation, which should be the primary intention in curative treatment of unresectable lung cancer / lung oligometastases. Since 2/2003 our insti- tution performs eSRT at the Novalis® (BrainLAB, Heimstetten, Germany). This phase-II-study was intended to find out feasibility, side effects and clinical response after eSRT. Materials/Methods: 213 Poster Abstracts
From 2/2003 to 05/2005, 20 pts. with up to 5 lung tumors (3 pts. with non small cell lung can- cer, 17 pts. with oligometastases, n=39 PTVs) received either 5x7 Gy or 5x8 Gy hypofractionat- ed stereotactic radiotherapy combined with abdominal pressure after ExacTrac® positioning and isocenter verification. Radiation dose was prescribed to the 90%-isodose, covering a median GTV and PTV of 8.43 and 35.34 cc. All but one (conformal beam) were treated by dynamic arc tech- nique. Results: The irradiation technique could perfectly fit the following RTOG-quality assurance guidelines (med, mean, min, max): Homogeneity 1.16 1.16 1.02 1.36 Conformity 1.29 1.38 1.12 1.98 Coverage 97.82 % 96.64 % 86.60 % 100 % Median doses to the normal lung tissue (right/left lung) was per fraction 6%/12% of total lung volume >2Gy, 2%/6% >4Gy and 1%/3% >6Gy. 26 /39 cases showed grade-1 lung toxicity, 4 grade-2 after a median FU of 66 d, after 124 d only 8 cases with grade 1 tox.. CR, PR, NC/PD was found in 25, 10, 4 cases with no significant difference between dose concepts. Conclusion: Extracranial hypofractionated stereotactic radio- therapy with up to 5x8 Gy is a safe and effective treatment. Dose limiting toxicity was not reached.
Dose escalation in the treatment of lung cancer with CyberKnife without increasing the dose to the organs at risk: a treatment planning study compared to 3-D radiotherapy P1-24 Jean-Briac, Prévost (1); Joost, Nuyttens (2); John, Praag (1) (1) Erasmus MC-Daniel den Hoed Cancer Center - Radiation Oncology; (2) Erasmus MC - Radiotherapy Rotterdam, The Netherlands Dose escalation in the treatment of lung cancer with CyberKnife without increasing the dose to organs at risk: a treatment planning study compared to 3-D radiotherapy. Purpose: The CyberKnife is a 6 MV linear accelerator, mounted on a multi-jointed robotic arm, allowing flexible delivery of (non-)coplanar beams. This frameless stereotactic radiotherapy system enables auto- matic correction for respiratory motion based on synchronic respiratory tracking. To investigate the capacity to deliver high doses to the tumor while respecting the tolerance dose of the organs at risk (OAR) we compared the treatment plans of the CyberKnife with three dimensional radio- therapy (3-D RT). Methods and materials: Ten patients with T1-2 N0 M0 lung cancer and previ- ously treated with 3-D RT were selected. All patients were replanned with the CyberKnife treat- ment planning system. The tumor was contoured as the GTV. The CTV was equal to the GTV + 5mm margin in all directions and the PTV = CTV + 3 mm margin in all directions. The constraints were set to minimize the dose to the lung and adjacent OAR. A total dose of 45 Gy in 3 fractions was prescribed to the 80% isodose line. For the 3-D RT planning, a GTV was defined with a slow scan. A GTV mobile was determined by adding 5mm to the GTV slow. A margin of 10 mm was added to the GTV mobile to create the PTV. A dose of 60 Gy (20 fractions) was specified accord- ing to ICRU 50. The analysis of the treatment plan was performed using dose volume histograms (DVH) of PTV and OAR. To enable comparison, the doses of both treatment plans were calculat- ed to equivalent doses in 2 Gy fractions (EQD2) using the linear quadratic model with an a/b ratio of 3 Gy for the organs at risk and 10 Gy for the tumor. Results: The mean of the minimum EQD2 administered to the PTV by the CyberKnife and the 3-D RT was respectively 95.5 Gy and 61 Gy (p<0.05). A mean of the maximum EQD2 of 134.6 Gy and 69 Gy was administered to the PTV by respectively the CyberKnife and 3-D RT. The V20 of the lung, calculated after substracting the PTV, of the CyberKnife and 3-D RT was respectively 8.3% and 6.8% (p=0.0001). The dose to the other OAR was below tolerance level. Conclusions: With the CyberKnife, a much higher biologi- 214 Poster Abstracts
cal dose can be administered to the PTV compared to 3-D RT, with respect of the tolerance dose to the OAR (e.g. V20). Current experiments in the tracking of lung tumors with the CyberKnife are conducted.
The combined stereotactic procedures for cystic cerebral metastatic tumors: A possible pitfall in ‘one day double procedures’ P1-25 In-Young, Kim (1); Jung, Shin (2); Tae-Young, Jung (1); sam-Suk, Kang (1) (1) Chonnam University Medical School - Brain Tumor Clinic & Gamma Knife Center, Department of Neurosurgery; (2) Chonnam University Medical School - Department of Neurosurgery Kwangju, Republic of Korea Objectives Although surgery has been a predominant choice in cases of cystic metastatic tumors, stereotactic aspiration and consecutive stereotactic radiosurgery has also been tried for specific cases, Two procedures are considered to be convenient for both patients and physician, because they could be carried out in a day with one frame application. However, a possible pitfall in one day double procedures is that they might not be very successful in reducing the tumor volume. Materials & Methods Two patients with cystic metastatic tumors underwent stereotactic aspiration and catheter insertion for postoperative cystic fluid drainage with the guidance of neuronavigation. On the same day, after the confirmation that there was no more cystic fluid into the drainage bag, computed tomography (CT) was performed to verify if there was no remained cystic fluid. The gamma knife radiosurgery (GKR) was performed on the next day. The follow up MRI was under- taken three months after these procedures. Results The preoperative tumor volumes were 60.8, 56.5, 13.4 mm3, respectively. The volumes after stereotactic aspiration and full drainage were 44.7, 33.6, 9.8 mm3 according to the CT, and we found that some remained cystic fluid in the low density areas in the targeted lesions. On the next day, we observed that there was an additional cystic fluid drainage during the night. The amount of drained cystic fluid during the night was about 13 cc, 8 cc, 1 cc, respectively. GKR was performed after catheter removal. The volumes at the time of GKR were reduced to 40.1, 31.1, 9.5 mm3, and the prescription doses were 12 Gy, 18 Gy, 20 Gy, respectively. The magnetic resonance images after three months showed a remarkable marked volume reduction of those tumors. Conclusion Considering the requirement of minimized volume of the cystic tumors at the time of GKR, the confirmation of the full drainage of cystic fluid prior to GKR is essential in the stereotactic cyst aspiration and consecutive GKR.
The benefit of Gama Knife radiosurgery in the treatment of thalamic and brainstem metastases P1-26 Wolfgang, Kreil (1); Verena, Weigl (1); Josef, Luggin (1); Sandro, Eustacchio (1); Georg, Papaefthymiou (1); Oskar, Schröttner (1) (1) Medical University Graz - Dept. of Neurosurgery Graz, Austria Introduction: The role of gamma knife radiosurgery (GKR) in the treatment of metastatic lesions located in the brainstem and thalamus is investigated in order to examine the risk benefit ratio of this method. Whereas surgical removal or fractionated radiation are associated with severe neu- rological deterioration of the patient, GKR has proved to be a favorable alternative treatment. Materials and methods: 22 patients with metastases in the brainstem area, treated by GKR 215 Poster Abstracts
between 1992 and 2002, are reviewed regarding their neurological outcome and the tumors´ response to the treatment. Tumor locations included the thalamus (8), pons (7), midbrain(4) and medulla oblongata (3). The median dose to the tumor margin was 17 Gy (range 12 – 25). The median follow up time in these patients was 7,1 months (range 1 – 30,5). Results and Conclusions: Tumor progression was controlled in all patients. No patient died or developed a new neurological deficit from growth of a radiosurgically treated tumor. There was no evidence of delayed adverse radiation effects in any patient. Up to now, at least in literature, little atten- tion has been paid to the management of patients with brainstem and thalamic metastasis, prob- ably because of their poor prognosis. But, regarding the local control rate in the tumors and the neurological outcome especially the Karnofsky Index, patients seem to achieve effective palliation by GKR of brainstem metastases.
Clinical impact of high-resolution MRI on stereotactic radiosurgery for patients with brain metastases P1-27 Julian, Perks (1); William, Hall (1); Conrad, Pappas (1); James, Boggan (2); Robin, Stern (1); John, Hartman (3); Claus, Yang (1); Richard, Latchaw (6); Allan, Chen (1) (1) U.C. Davis Cancer Center - Radiation Oncology; (2) U.C. Davis - Neurosurgery; (3) U.C. Davis - Radiology Sacramento, USA In the evaluation and treatment of intracranial metastatic disease, the radiosurgery team at UCDMC has at times found more metastatic lesions on the treatment day than noted in the work up process. To this end, over an 18-month period, the first 63 patients with metastatic lesions were analysed. Patients were categorized by age, gender, KPS, control, primary, and previous radiotherapy. The number of lesions noted prior to the day of treatment, the number treated and whether all present lesions could be treated were recorded. The MRI scan performed for the refer- ral was also categorized in terms of slice thickness and contiguity. The referral pattern matched well with general radiosurgery practice, in terms of primary, age range, control etc. Whole-brain radiotherapy was given prior in 23 cases. Nine patients had prior radiosurgery. On average, patients had two lesions (mean 2.08, range 1-8, median 1) at referral but had three treated (mean 2.95, range 0-13, median 2). Significantly, there were 11 cases (17%) where treatment was compromised as not all excess lesions could be treated with the original frame placement and further treatment was necessary. Analysis of all contributing factors shows that the resolu- tion (slice thickness) of the referral imaging study (not just the time interval between referral MRI and treatment) is the major determining factor for the number of lesions encountered. This data clearly demonstrates an increase in the number of lesions treated compared to those shown at referral. A full patient work up should determine as accurately as possible the number of metas- tases that will be encountered in order to optimally plan treatment, avoid patient distress and the need for additional treatment. Our conclusion is that that the imaging study used for the referral is critical and should ideally match the parameters used on the day of treatment.
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Evaluation of prognostic factors in patients affected by brain metastases from lung cancer treated with gamma knife radiosurgery P1-28 Piero, Picozzi (1); Alberto, Franzin (2); Silvia, Snider (2); Francesca, Marchesi (3); Luca, Attuati (2); Antonella, Del Vecchio (1); Vanessa, Gregorc (4) (1) Ospedale San Raffaele - Stereotactic Neurosurgery & Gamma Knife Department; (2) Ospedale San Raffaele - Neurosurgery Department; (3) Ospedale San Raffaele - Department of Oncology Milano, Italy INTRODUCTION: standard treatments in patients with lung cancer brain metastasis are surgery, WBRT and radiosurgery. We analyzed our consecutive series of patients to assess the role of GammaKnife Radiosurgery and evaluate the major prognostic factors in such population. MATE- RIALS AND METHODS: between December 1993 and April 2004, 227 (180 male and 47 female) patients were treated in our centre for brain metastasis from lung cancer with GammaKnife. Mean age at treatment was 61 years. In most of them (70%) histology samples of primary tumour was adeno-ca. In 129 patients (56,8%) a systemic illness control was not obtained, otherwise in 40 pts (17,62%) the tumour resulted stable, in 58 pts (25,55%) there was no strumental evidence of illness. 82 pts were also affected by other metastasis. Every patient was ranked in RPA and SIR classification. 35 resulted in RPA class I, 185 pts in class II, 7 in class III. 116 pts presented with a single lesion, the rest with multiple brain metastasis. Mean dose to tumour was 22.6 ± 3.5 Gray to 50% isodose. Mean lesion volume was 4,6 mm3 ± 5,4. Survival curves were obtained with Kaplan-Meyer method, prognostic factors were assessed trough Cox proportional hazard ratio. Univariate and multivariate analysis were performed to evaluate prognostic factors. RESULTS: Mean survival rate was 8.3 months. One, two and three years survival rate was 38%, 15% and 7%. Local tumour control was not achieved in 103 pts, who underwent a second line treatment (GammaKnife, surgery or WBRT). In univariate testing, KPS, age, SIR and RPA ranking, volume of metastasis are significantly associated with outcome. In multivariate analysis, only RPA has shown to be affordable in predicting the outcome, with an independent Hazard Ratio of 1.75. This study supports the use of GammaKnife in this group of patients, especially those in good general condition.
Linac based sterotactic radiosurgery (SRS) of brain metasases - 10 years experience P1-29 Martin, Chorvath (1); Martina, Skoknova (2); Yaroslav, Parpaley (2); Augustin, Durkovsky (3); Miron, Sramka (2); Juraj, Steno (4); Elena, Boljesikova (1) (1) St. Elisabeth Cancer Institute - Department of Radiotherapy; (2) St. Elisabeth Cancer Institute - Department of Radiosurgery; (3) St. Elisabeth Cancer Institute - Department of Radiology; (4) Faculty Hospital of the Comenius University - Department of Neurosurgery Bratislava, Slovakia Purpose: SRS is a well-accepted method for treatment of brain metastases. We reported data of patients who underwent Linac based SRS in a period from 1992 - 2002 at Radiotherapy Dept. St. Elisabeth Cancer Institute as a retrospective study. Material and Methods: From 1992 to 2002 we treated with SRS 80 patients with brain metastases. Five patients had more than three lesions. The follow-up for 15 patients was lost. 60 patients (34 male, 26 female) were included into sur- vival analysis with up to three lesions in brain. The age of patients varied between 30 - 81 years. 217 Poster Abstracts
The primary site of tumors were as follows: 14 pts with lung carcinoma 23,3%, 10 pts with renal carcinoma 16,6%, 10 pts with unknown primary site 16,6%, 9 pts with colorectal carcinoma 15%, 6 pts with mammary carcinoma 10%, 4 pts with malignant melanoma 6.6%. The volume of metastases varied from 0.1 cm3 to 22,5 cm3. SRS was applied with Clinac 2100 Varian 6 MV X. The treatment dose was calculated on 80% isodose. The minimal tumor dose TD min. ranged from 12.0 Gy to 24.0 Gy, average 17.0 Gy. The maximal tumor dose TD max. ranged from 14.25 Gy to 31.0 Gy, average 24.0 Gy. Cumulative survival of all patients was calculated by the method of Kaplan - Meier. Results: Overall survival (OS) was 6.2. months for all patients. We observed shortest OS in patients with brain metastases of malignant melanoma: 3.8 months and unknown primary site: 4.1 months. The longest OS we observed in patients with brain metastases from mammary carcinoma was 23 months. OS in patients with brain metastases of pulmonary and col- orectal carcinoma were 16 and 15 months respectively. No significant difference between OS of patients in the group with single metastases and in a group with two or three metastases was observed (log rank 0.5)Conclusions: SRS is an efficient, accessible and non-invasive method reducing radiotherapy-induced side effects, with a promising potential to increase survival of patients with up to three metastases of malignant tumors in brain.
Gamma knife radiosurgery for brain metastasis. Analysis of survival and prognostic factors P1-30 Alberto, Franzin (1); Piero, Picozzi (1); Silvia, Snider (2); Camillo, Ferrari Da Passano (1); Lorenzo, Gioia (1); Massimo, Giovanelli (1) (1) Ospedale San Raffaele - Neurosurgery Department; (2) Ospedale San Raffaele - Stereotactic Neurosurgery & Gamma Knife Department Milano, Italy Introduction: Standard treatments for patients with brain metastasis are surgery, whole brain radiotherapy (WBRT) and stereotactic radiosurgery (RS). Single treatment is not alweays afford- able in case of large cystic tumors. This study asseses the role of stereotactic drainage followed by gamma knife radiosurgery (GKRS) in the treatment of large cystic brain metastasis. Patients and Methods: Inclusive criteria of the study were: no prior whole-brain radiation therapy or surgical resection, a maximum number of 4 lesions on MRI, a tumour diameter <4 cm, one cystic lesion, KPS ? 60, minimum follow-up period of 6 months after GKRS. Between February 2001 and March 2004, 15 patients with 33 tumours (18 cystic tumour and 15 solid), fulfilled the eligibility criteria and were included in this study (9 male, 6 female; mean age 60 yrs; range 38-75 yrs). The pri- mary cancer was lung (NSCLC) in 8 pts (57%), breast in 2 pts (13%), parotid in 1 pt (6,5%), melanoma in 1 pt (6,5%), kidney in 1 pt (6,5%), colon in 1 pt (6,5%), unknown in 1 pt (6,5%). Before stereotactic drainage the mean cystic tumour volume was 19,95 ml (ranging between 3,8 and 48 ml). At the end of stereotactic drainage, before GKRS, mean tumour volume was 9,59 ml (1,2–18 ml). Mean prescription dose to the tumour margin was 19,6 Gy (range 16 - 25 Gy); at 50% isodose. MRI follow up was performed every three months. We analysed survival period and local tumor control rate. Results: Mean follow-up period was 10 months. Local tumour con- trol was achieved always in the cystic tumours. Two patients died in the first month after the treat- ment: one for carcinomatosis meningitis and one for pulmonary embolia. Conclusions: This study supports the use of stereotactic drainage approach in case of large-volume multiple and cystic brain metastasis. 218 Poster Abstracts
Stereotactic drainage and gamma knife radiosurgery of cystic brain metastasis P1-31 Alberto, Franzin (1); Micol, Valle (1); Massimo, Giovanelli (1) (1) Ospedale San Raffaele - Neurosurgery Department Milano, Italy Introduction: Standard treatments for patients with brain metastasis are surgery, whole brain radiotherapy (WBRT) and stereotactic radiosurgery (RS). Single treatment is not alweays afford- able in case of large cystic tumors. This study asseses the role of stereotactic drainage followed by gamma knife radiosurgery (GKRS) in the treatment of large cystic brain metastasis. Patients and Methods: Inclusive criteria of the study were: no prior whole-brain radiation therapy or surgical resection, a maximum number of 4 lesions on MRI, a tumour diameter <4 cm, one cystic lesion, KPS > 60, minimum follow-up period of 6 months after GKRS. Between February 2001 and March 2004, 15 patients with 33 tumours (18 cystic tumour and 15 solid), fulfilled the eligibility criteria and were included in this study (9 male, 6 female; mean age 60 yrs; range 38-75 yrs). The primary cancer was lung (NSCLC) in 8 pts (57%), breast in 2 pts (13%), parotid in 1 pt (6,5%), melanoma in 1 pt (6,5%), kidney in 1 pt (6,5%), colon in 1 pt (6,5%), unknown in 1 pt (6,5%). Before stereotactic drainage the mean cystic tumour volume was 19,95 ml (ranging between 3,8 and 48 ml). At the end of stereotactic drainage, before GKRS, mean tumour volume was 9,59 ml (1,2–18 ml). Mean prescription dose to the tumour margin was 19,6 Gy (range 16 - 25 Gy); at 50% isodose. MRI follow up was performed every three months. We analysed survival period and local tumor control rate. Results: Mean follow-up period was 10 months. Local tumour con- trol was achieved always in the cystic tumours. Two patients died in the first month after the treat- ment: one for carcinomatosis meningitis and one for pulmonary embolia. Conclusions: This study supports the use of stereotactic drainage approach in case of large-volume multiple and cystic brain metastasis.
Recurrent metastases following whole brain irradiation: hope for patients in RPA class III? P1-32 Markus, Gross (1); Steffi, Pracht (2); Klaus, Hamm (2); Rita, Engenhart-Cabillic (3) (1) Philipps University Marburg - Department of Radiotherapy; (2) Helios-Kliniken Erfurt - Department of stereotactic Neurosurgery and Radiosurgery; (3) Philipps University Marburg - Radiotherapy and Radiooncology Department Marburg, Germany Background: Radiosurgery is an effective therapy for brain metastases, but has failed to show a substantial survival benefit in patients suffering from recurrent metastases after whole brain radiotherapy (WBRT) so far. Therefore, we evaluated the prognostic factors derived from the RTOG recursive partitioning analysis (RPA) to identify patient subgroups deriving a benefit from this method. Patients and Methods: A total of 46 patients with 70 recurrent cerebral metastases pre- viously treated with WBRT underwent single-dose linac radiosurgery. All patients were classified into the three RPA prognostic classes based on age, performance score, and presence of extracra- nial tumour manifestations. The impact of prognostic factors on survival of these patients and the prognostic value of RPA classes in this collective was determined. Results: In RPA class I (Karnofsky performance score ≥ 70, primary tumour controlled, no other metastases, age < 65 years), radiosurgery resulted in a median survival of 11.5 months (n = 11) which was signifi- 219 Poster Abstracts
cantly longer than for RPA class III (Karnofsky performance score < 70) (n = 22, 3.7, p<0.005), or RPA class II (all other patients) (n=14, 4.0, p<0.05). No significant difference in survival between RPA class II and RPA class III was seen (p>0.5). Significant favourable prognostic fac- tors affecting survival were Karnofsky performance score, absence of extracerebral tumour, lesion volume < 4 ml, encompassing dose > 18 Gy, and neurological symptoms prior to radiosurgery. Conclusion: Radiosurgery in patients with recurrent cerebral metastases results in a substantial survival benefit preferably in patients in with a low systemic and cerebral tumour burden. However, there was even a survival of about 4 months in patients of RPA class III, therefore jus- tifying radiosurgery for these patients, as well.
Gamma knife radiosurgery for the cavernous sinus metastases and invasion P1-33 Yoshiyasu, Iwai (1); Kazuhiro, Yamanaka (1); Masaki, Yoshimura (1) (1) Osaka City General Hospital - Department of Neurosurgery Osaka, Japan Background: We evaluated the efficacy of gamma knife radiosurgery for cavernous sinus metas- tases and invasion. Method: We treated and followed 21 patients with cavernous sinus metas- tases and invasion using gamma knife radiosurgery. Nine of these patients had nasopharyngeal cancer and 12 had distant metastases from other cancers. The volume of tumors ranged from 2.9 to 50.0 ml (median: 9.9 ml) and the radiation dose to the tumor margin was 10 to 21 Gy (medi- an: 14 Gy). Results: The median follow-up period was 9 months. Clinical symptoms were improved in 48 % of the patients after treatment, and tumor growth control was obtained in 67 % of the patients at their final follow-up. The actual one - year and two - year tumor growth con- trol rates were 68% and 43%, respectively. The mean survival time was 13 months. No patient suffered radiation injury. Conclusion: Gamma knife radiosurgery is a very useful therapeutic option for the treatment of cavernous sinus metastases and invasion, either as initial treatment or as an adjunct treatment for recurrences even in preirradiated patient.
Fatal intratumoral hemorrhage immediately after Gamma Knife radiosurgery for brain metastasis: Case report P1-34 Masahiro, Izawa (1); Mikhail, Chernov (1); Motohiro, Hayashi (1); Yuichi, Kubota (1); Hidetoshi, Kasuya (1); Tomokatsu, Hori (1) (1) Tokyo Women's Medical Univeristy - Department of Neurosurgery Tokyo, Japan OBJECTIVE: Radiosurgical treatment of brain tumors is sometimes considered free from significant acute complications or adverse effects. We report a rare case of fatal intratumoral hemorrhage immediately after gamma knife Radiosurgery (GKR) for brain metastasis. CASE PRESENTATION: A 61-year-old woman with lung cancer complicated by systemic dissemination, experienced an acute episode of headache, speech disturbances, and right-side hemiparesis. She had no history of arterial hypertension or coagulation disorders. CT and MRI disclosed 2 brain metastases. The largest tumor had a diameter of 4 cm and was located in the left frontal lobe, whereas the other one with a diameter of 1.5 cm was located in the left cerebellar hemisphere. The supratentorial neoplasm was removed microsurgically without any complications. GKR for infratentorial lesion was done in overall 3 weeks after manifestation of the cerebral disease. Marginal dose corre- 220 Poster Abstracts
sponded to 50% prescription isodose line and constituted 22 Gy, maximal dose was 44 Gy. No complications were marked during frame fixation, treatment by itself, or frame removal. Fifteen minutes after the end of GKR session the patient acutely fell into deep coma with cardiac arrest. Immediate resuscitation resulted in recovery of the cardiac rhythm, and urgent CT disclosed mas- sive intracerebellar hemorrhage in the vicinity to radiosurgically treated tumor. The family reject- ed surgical treatment. Despite intensive therapy the patient remained deeply comatose and died 4 days later. Autopsy confirmed hemorrhage in the brain metastasis and herniation syndrome. CONCLUSION: GKR for metastatic brain tumors should not be considered as absolutely risk free procedure. As shown in the described case, while rare, even fatal complications can occur, and their probability should be discussed with a patient and his or her family members during obtain- ing the informed consent for radiosurgical treatment.
Gamma knife radiosurgery for metastatic alveolar soft part sarcoma : a case report P1-35 Jang, Jae-Won (1); In-Young, Kim (1); Jung, Shin (2) (1) Chonnam University Medical School - Brain Tumor Clinic & Gamma Knife Center, Department of Neurosurgery; (2) Chonnam University Medical School - Department of Neurosurgery Kwangju, Republic of Korea Objectives Brain metastasis from alveolar soft part sarcoma (ASPS) is very rare, and there has been no report on the radiosurgery for the cerebral metastasis of ASPS. We used gamma knife radio- surgery (GKR) as a palliative treatment, and report the results. Materials & Methods A 32-year- old female visited our hospital due to progressive headache. Two years ago, she had underwent an operation to remove the parietal mass, and the histological diagnosis had turned out to be ASPS. The 3000cGy whole brain radiation treatment had been performed postoperatively. After the admission the magnetic resonance images (MRI) showed multiple lesions, and the first GKR was performed to the largest five lesions. The second GKR was performed three months later to the new largest six lesions at the time. The latest follow-up imaging was computed tomography ten months after first GKR. Results The mean diameter of the tumors was 16.8 mm (range 9.1- 30.7 mm). The prescription doses ranged from 12 Gy to 16 Gy. In ten tumors out of eleven, local tumor control was observed: size reduction 7, no increase in size 3. The size increase was observed only one tumor, but we had already observed the size reduction in that tumor six months after first GKR. The patient has been followed up regularly for one year, and the Karnofsky performance status became worse to 60 because of a number of newly developed cerebral lesions and systemic metastasis. Conclusion We report the experience of GKR in cerebral metasta- tic ASPS which is very rare. Similar to other cerebral metastatic tumors including sarcomas, the palliative effect of GKR is thought to be satisfactory in cerebral metastatic ASPS.
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Radiosurgery for the treatment of brain stem metastases: relationship between clinical status and survival P1-36 José, Lorenzoni (1); Daniel, Devriendt (2); Nicolas, Massager (3); Françoise, Desmedt (1); Stéphane, Simon (4); Paul, Van Houtte (2); Jacques, Brotchi (3); Marc, Levivier (1) (1) Hôpital Erasme - Centre Gamme Knife; (2) Institut J. Bordet - Radiothérapie; (3) Hôpital Erasme - Neurochirurgie; (4) Institut J. Bordet - Physique Brussels, Belgium Objective: To study results and survival of patients with brain stem metastases treated with radio- surgery. Material & Methods: Among 160 patients treated for brain metastases between December 1999 and December 2003, there were 15 patients (9.4%) with 17 brain stem metas- tasis. Volume of the lesions ranged from 0.012 to 2.4 cc (mean 0.56 cc). Treatment was per- formed with Leksell gamma knife C, with a median peripheral dose of 18 Gy (ranging from15 to 24 Gy) at a median isodose of 50% (ranging from 50 to 68%). Stratification of patients was done using the Recursive Partitioning Analyze (RPA), the Score Index for Radiosurgery in BM (SIR) and the basic score for brain metastases (BS-BM). Results: The primary tumor was lung in 8 patients, breast in 4, and other in 3. Nine lesions were located in the pons, 5 in the mesencephalon, and 3 in the medulla. All patients were followed clinically; radiological follow-up was available in 10 patients (67%). Tumor control was achieved in all but one followed lesion. There were no com- plications related to treatment. Median survival of patients with brain stem metastasis was 10.8 months, and was not different than the median survival of patients with metastases in other brain locations (13,3 months, p= 0.15). BS-BM score differentiates 2 groups of patients with different survival; RPA and SIR had borderline p values. Conclusions: Radiosurgery is an effective treatment of brain stem metastases. As for other intracranial locations, survival is determined by the clinical status at the time of treatment.
Stereotactic irradiation (STI) boost for multiple brain metastases P1-37 Hisato, Nagano (1); Takashi, Shuto (2); Yuji, Nakayama (2); Inomori, Shigeo (2) (1) Yokohama Rosai Hospital - Radiationoncology; (2) Yokohama Rosai Hospital - Neurosugery Yokohama Kanagawa, Japan Combination of whole brain irradiation (WBI) and Stereotactic irradiation (STI) is still a hot argu- ment especially when a patient has more than five metastatic brain tumors. Uncomplicated Control (UC); (k-NTCP)*TCP, which was advocated by Gerald J. Kutcher (1996), will give a way out of this difficulty. NTCP (normal tissue complication probability) was calculated by Flickinger’s inte- grated logistic formula, and TCP (tumor control probability) was derived from Colombo’s formula to make account of dose inhomogeneity of STI. One shot was set in the phantom brain and UC was calculated in two conditions, with WBI and without WBI. Then additional shot was set and calculation was performed. Another shot would add till the value of UC with WBI became larger than that of UC without WBI. This number of shots was gained with every collimator of gamma knife; 8, 14, 18mm collimator. When constant k was assumed 0.39 and the dose of WBI was 30Gy/10fxs/2wks, more than 16, 4, 3 shots made the UC value larger than the value without WBI, if the collimator size was 8, 14, 18mm respectively. This means that when tumors of patient were more then one centimeter in size and number of the tumors was more then five, WBI should be delivered concomitantly with STI. Combination of WBI and STI boost should be recommend- ed in these conditions. 222 Poster Abstracts
Localized therapy for limited metastatic disease to the brain: A Phase II study of surgery, stereotactic radiosurgery (SRS) and stereotactic radiotherapy (SRT) in favorable patients P1-38 Lucien, Nedzi (1); John Wilson, Walsh (2); Roy, Weiner (3); Bryan R., Payne (4); Ellen, Zakris (1); Robert, Sanford (5); Timothy, Pearman (6); Paul, Rosel (7); Raja, Mudad (3); Anna, Hall (8); Judy, Weber (9) (1) Tulane University - Radiation Oncology; (2) Tulane University Medical Center - Department of Neurosurgery; (3) Tulane University - Department of Hematology/Oncology; (4) LSU School of Medicine at New Orleans - Department of Neurosurgery; (5) Tulane University - Radiation Oncology; (6) Tulane University - Psychology; (7) Tulane University - Radiology; (8) Tulane University Hospital and Clinic - Radiation Oncology; (9) New Orleans Regional Gamma Knife Center - Nursing New Orleans, USA Background: Surgery, SRS and SRT are local therapies for selected patients with a limited number of brain metastases. Occasional patients are treated with a combination of these therapies, but this has not been studied prospectively. Purpose: To determine the feasibility and efficacy of sur- gery, SRS and SRT in favorable patients with 1-4 brain metastatses. Materials and Methods: In 2001-2004, 23 patients with 1-4 intraparenchymal brain metastases and KPS>= 70%were enrolled in an institutional review board approved clinical trial. Treatment for each lesion was determined based on tumor size. Tumors <=2cm received SRS; tumors >2cm received either Surgery+SRT(25Gy/5) or SRS+SRT(25Gy/5), depending on patient and physician preference. Patients were followed with MRI scans every three months. Additional brain metastases detect- ed in follow-up were treated on study if KPS>=70% at the time of detection. Results: Five out of 23 patients were found to be ineligible: two for >4 metastases at treatment; two for extra- parenchymal location; one for no metastasis at treatment. Primary site was as follows: 8 breast; 6 lung; 2 unknown; 1 anal; 1 kidney. Median KPS was 80% (70-100%). Eight (44%) had a soli- tary metastasis, eight (44%) had no extracranial disease and four (22%) had radiographically pro- gressive metastases more than three months following whole brain radiotherapy (WBRT). Forty- seven lesions in 18 patients were treated on study: 42 SRS; 2 SRS+SRT; 3 SRT. No lesion was treated surgically. Median SRS tumor volume was 0.3cc (0.02-12). Median SRS dose was 20Gy (16.2-24) prescribed to the 65% (45-80) isodose. The median minimum target dose was 21.6Gy (13.7-33.2). Among 10 SRS targets >1cc, the median conformity index was 1.5(1.1-2.5). The median SRT target volume, dose and isodose were 28.3cc (8.7-59.6), 25Gy and 85% (80-89), respectively. The median SRT conformity index was 1.4 (1.3-1.7). With a median follow-up of 6.2 months (0.6-20.5), 12 patients have died: 11 with progressive disease, one from a steroid-relat- ed GI bleed. There have been six intracranial failures: three local failures, two treated off study with surgery and one treated off study with SRS+surgery; two elsewhere brain failures treated on study with SRS; one leptomeningeal failure. Conclusions: SRS and SRT are prospectively fea- sible in patients with 1-4 brain metastases and KPS>=70%. A clinical trial remains ongoing.
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Gamma knife (GK) radiosurgery for small brain metastases P1-39 Ouzi, Nissim (1); Daniel, Devriendt (2); Nicolas, Massager (3); Philippe, David (4); Françoise, Desmedt (1); Olivier, Coussaert (1); Stéphane, Simon (5); Paul, Van Houtte (2); Jacques, Brotchi (3); Marc, Levivier (1) (1) Hôpital Erasme - Centre Gamme Knife; (2) Institut J. Bordet - Radiothérapie; (3) Hôpital Erasme - Neurochirurgie; (4) Hôpital Erasme - Neuroradiologie; (5) Institut J. Bordet - Physique Brussels, Belgium Introduction: With the advent of high-resolution magnetic resonance (MR) imaging and tighter follow up, small and often multiple brain metastases (BM) are detected. Radiosurgery plays an important role, together with conventional microsurgery and whole brain radiotherapy, in a com- prehensive treatment strategy for these patients. Here, we evaluate the efficacy of GK radio- surgery in controlling small BM while considering the potential effect of various maximal radia- tion doses on response. Methods: Between 2000 and 2004, 281 patients harboring BM were treated with GK radiosurgery. A subgroup of 134 small lesions (56 patients) measuring up to 100 mm_ in volume, received maximal doses of 24.5 to 53.3 Gy (18 to 24 Gy to the 45- 85% iso- dose line). Follow-up with sequential MR, MR spectroscopy and positron emission tomography (PET) imaging evaluated changes in tumor size. Results: Sixty-four lesions were followed up, 3- 43 (median 10) months after treatment. The one year tumor control rate was 91% (43 % reduc- tion and 48% stabilization in size). Increased lesion volume was recorded 4-10 months post treat- ment in 3 patients. One had two lesions, inactive by PET scan. In another patient, one lesion expanded initially and later decreased in volume. A second lesion enlarged 7 and 10 months after treatment. MR spectroscopy suggested inactive tumor. In a third patient, 3 lesions expanded 4 and 6 months after treatment. All melanoma patients responded to treatment but difference in response could not be attributed to other pretreatment parameters or to maximal dose delivered. Conclusions: GK radiosurgery for patients with small BM can achieve high tumor control rate irre- spective of the maximal dose delivered. It can be administered in one session, treating simulta- neously lesions of different size and location, and serves as an important adjunct to multi-modal- ity treatment of these patients.
Fractionated gamma knife radiotherapy for huge metastatic tumor P1-40 Ushikubo, Osamu (1) (1) Kasai cardiology and neurosurgery hospital - neurosurgey Tokyo, Japan OBJECT; The purpose of this study was to evaluate the safety and efficacy of gamma knife radio- therapy for the treatment of huge metastatic brain tumor. Methods; Fifteen lesions of ten patients harboring metastatic brain tumors were treated GKRT . As for one, primary lesion was not clear in them. Tumor max diameter was more than 3cm in 11lesions. One lesion was recurrence of pre- viously irradiated lesion. Two tumors were located in near brainstem. The tumor volume ranged from 1900 to 28600 mm3. (median 20800 mm3) The peripheral dose to the tumor margin was 10Gy and the whole tumor was covered. The treatment went three times every 2weeks. The tumor control rate was 73%. We had to do craiotomty for one patient whose tumor was received previously irradiation. Pathology was tumor necrosis. Three lesions of two patients progressed following therapy. Conclusions; It was investigation phase, but it was suggested that one of the 224 Poster Abstracts
therapies for giant metastatic brain tumor could get possible to be optional by this fractionated gamma knife radiotherapy.
Stereotactic radiosurgery boost for metastatic brain tumors receiving WBRT P1-41 George, Pissakas (1); V, Georgolopoulou (2); K, Doukaki (3); S, Mourgela (4); E, Andriotis (5); M, Kalogeridou (3); S, Kosmidou (3); G, Arhontakis (4); E, Pappas (2); I, Kouvaris (6); A, Sotiropoulou (3) (1) Alexandra Athens General Hospital - Radiation Oncology; (2) St.Savvas Hospital - Medical Physics; (3) St.Savvas Hospital - Radiation Oncology; (4) St.Savvas Hospital - Neurosurgery; (5) St.Savvas Hospital - Radiology; (6) University of Athens - Radiation Oncology Athens, Greece Purpose: Stereotactic radiosurgery (SRS) is nowadays an option for increasing the dose received by patients with brain metastases after WBRT has been completed. This study presents the expe- rience of our institution from applying linac based SRS as a boost treatment to selected patients undergoing WBRT. Materials/Methods: Between March 2000 and February 2004, forty-nine patients with metastatic tumors were selected to undergo an SRS boost after their WBRT. Criteria were 1 to 3 lesions, age 18 years or older and good performance status (KPS>70). For stereo- tactic treatments we use the 6 MV beam of an Elekta SL18 linac to which a floorstand isocentric subsystem is attached. The WBRT was given at 250 cGy/fraction to 3750 cGy in 3 weeks or at 300 cGy/fraction to 3000 cGy in 2 weeks. The single fraction SRS dose followed one month after completion of radiotherapy and was tumor-size dependent ranging from 1300 to 2000 cGy. Our series comprised of 36 male and 13 female patients, ages ranging from 34 to 79 years (median: 54) with a median KPS of 90 (range: 70-100). Lesion volume ranged from 0.134 to 11.1 cc (medi- an 1.66cc) and solitary tumors were present in 67% of our cases. Follow-up time ranged from 2 to 34 months (median: 6). Results: The one-day SRS procedure, involving frame fitting under local anesthesia, CT scan with a localizer and irradiation after a few hours of waiting for image fusion and treatment planning to be prepared, was received well by all patients without any complica- tions. Patient follow-up, 4 months after treatment, indicated elimination of lesions in 32% of our cases, stable size in 8% and volume reduction in 60%. 7 months after treatment, these rates were reduced to 27%, 7% and 51%, respectively, since 3% of our patients showed local relapse at the treated area and 8% developed new lesions. The remaining 4% of our cases, that initially showed a reduction in tumor size, recurred at subsequent follow-ups with increasing lesion volume. Conclusion: SRS is a useful method for boosting the dose received by metastatic brain tumors and achieving good local control rates.
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Stereotactic irradiation for metastatic brain tumors from hepatocellular carcinoma P1-42 Masao, Tago (1); Kenshiro, Shiraishi (1); Keiichi, Nakagawa (1); Keisuke, Maruyama (2); Hiroki, Kurita (3); Masahiro, Shin (4); Atsuro, Terahara (4); Shunsuke, Kawamoto (5); Kuni, Ohtomo (1) (1) University of Tokyo Hospital - Department of Radiology; (2) University of Tokyo Hospital - Department of Neurosurgery; (3) Kyorin University Hospital - Department of Neurosurgery; (4) Toho University Omori Hospital - Department of Radiology; (5) Dokkyo University School of Medicine - Department of Neurosurgery Tokyo, Japan Introduction: We retrospectively analyzed the outcomes of stereotactic irradiation (STI) for metastatic brain tumors from hepatocellular carcinoma (HCC). Materials and Methods: Eleven patients with 22 metastatses from HCC were treated by STI at our hospital since 1991. We eval- uated nine patients (eight males and a female) with 20 tumors who have undergone at least one follow-up visit. The median and mean tumor sizes were 13.8 mm and 14.6 mm, respectively (range: 2.0 - 27.7 mm). Thirteen tumors were treated by stereotactic radiosurgery using 15 to 25 Gy to the margin, the remainder were irradiated between 34 and 38 Gy in 5 fractions at the mar- gin (all received 40 Gy in 5 fractions at the isocenter). Results: The median clinical follow-up peri- od was 5.2 months (range: 1.7 - 19.7 months). Six patients died, and three were alive at the last follow-up. The median survival was 5.8 months after STI. The actuarial 1-year survival rate was 42 %. The median radiological follow-up period was 2.2 months (range: 0.7 - 15.4 months). 16 of 20 tumors (80%) were controlled at the last imaging study. The actuarial 1-year control rate was 57 %. Progression in four tumors was observed between three and four months after the treatment, which were irradiated lower biological effective doses. Conclusions: STI provides rea- sonable effect for brain metastases from HCC. Higher dose may be necessary for long-term tumor control.
Radiosurgical treatment of “radioresistant” cerebral metastases P1-43 Charles, Valery (1) (1) Hopital de la Pitie-Salpetriere - Service de neurochirurgie Paris, France Treatment of secondary cerebral lesions that were previously considered as radioresistant (RR) with fractionated regimen is now possible using radiosurgery. We reviewed datas of patients treated between 1994 -2002 for kidney or melanoma brain metastases. Median follow-up was 10 months . Among the 35 patients presenting 85 secondary melanoma lesions, mean age was 52 (25-73), initial cancer was controled in 46% of the cases. The score index (SIR) was of 1 in 4 cases, of 2 in 19 cases, of 3 in 12 cases. Median volume of lesions was 1,58 cm3 (0.04-63.6), minimum delivered dose was 14.4 Gy (10-19.4) and maximum dose was 22.8 Gy (13.7-47.8). Among the 31 patients presenting 70 secondary lesions of kidney, mean age was 58 (38-75), ini- tial cancer was controled in 22.6% of the cases. The SIR was of 1 in 3 cases, of 2 in 20 cases, of 3 in 8 cases. Median volume was 1.36 cm3 (0.02-31.6), minimum delivered dose was 14.8 Gy (10.8-19) and maximum dose was 22.1 Gy (14.3-39.5). Kaplan-Meier analysis showed a medi- an survival of 200 days for melanoma and of 266 days for kidney. Local control at 3, 6 and 12 months was 98, 92, 75.3% respectively for melanoma, and 98, 89.6, 89.6% respectively for kid- ney. The rate of grade>2 RTOG complications was 6%. Survival predicting factors for RR lesions were : histology (p=0.05) and SIR index (p=0.01). Multivariate analysis of survival predictors 226 Poster Abstracts
performed separately for each histology showed no significant factors for melanoma. Age (p=0.04), disease control (0.01) and SIR (p= 0.01) were found significant for kidney. No factor was found for prediction of the risk of relapse in a univariate analysis. Additional WBRT (35% cases) did not influence cerebral control (p=0.5). Radiosurgery alone is a safe, non invasive and efficient technique for patients presenting radioresistant cerebral metastases.
Repeated in-situ recurrence of brain metastases after radiosurgery and resection: dural contact as a risk factor P1-44 Dirk, Van Den Berge (1); Guy, Soete (1); Christine, Collen (2); Recai, Ates (3); Katrijn, Van Rompaey (4); Jean, D'Haens (4); Guy, Storme (1) (1) AZ VUB - Radiothérapie; (2) AZ-VUB - Radiotherapy; (3) AZ VUB - Neurochirurgie Brussels, Belgium The widespread use of stereotactic radiotherapy as well as the improvement of systemic treat- ments has changed the passive and fatalistic attitude towards patients with metastasis to the brain. In a small subgroup of patients impressive survival times in excellent quality of life can now be achieved, but al but a few patients ultimately succumb to their disease either due to extracra- nial progression, development of new intracranial disease or repeated recurrence of previously treated brain metastases. In this retrospective study we looked in our database covering the last decennium for repeated in-situ recurrence of brain metastases in patients surviving more than one year. The presence of contact with, or frank invasion of the dura was almost universal in this group of patients. In some cases multiple metastases recurred selectively in lesions with meningeal contact and not in others. This data suggest that, especially in patients with otherwise good prognostic factors, measures should be taken to treat such lesions more aggressively by combining modalities, taking larger resection / irradiation margins or increasing dose.
Paradigm shift in management of patients with multiple brain metastases: From whole brain radiotherapy to gamma knife radiosurgery P1-45 Masaaki, Yamamoto (1); Bierta, Barfod (1); Yoichi, Urakawa (1) (1) Katsuta Hospital - Mita Gamma House Hitaxhi-Naka, Japan Gamma knife (GK) radiosurgery is now the primary treatment in an increasing number of patients with brain metastases (METs), both radiosensitive and radioresistant, single and multiple. New, not yet widely known, concepts pertaining to GK radiosurgery for brain METs are presented based on our personal series of 1206 patients (1596 procedures, 10,557 tumors) with brain metastases who underwent GK treatment (1992 – 2004). The most common primary tumor was lung (61.5%), fol- lowed by breast (10.1%), colon-rectum (8.7%), kidney (5.1%), stomach (2.9%) others (8.8%) and unknown (2.9%). In our experience, GK is a safe and effective treatment even in patients with 30- 40, or more, tumors. Though lesion size is a limitation, high tumor control rates are possible when lesions are irradiated with at least 18 Gy. Recurrence and radiosurgical complications are rare in such cases. Symptomatic complications, i.e. radionecrosis of normal brain tissues, are slightly more common in long-surviving cases. However, in more than 85% of patients, death is due to diseases brain metastatic. Thus, most do not survive long enough for complications to manifest. Therefore, good brain function is generally maintained till death. Factors predicting longer survival are youth, 227 Poster Abstracts
better performance status, fewer tumors and absence of active non-brain disease. Although some investigaters report re-treatment for new lesions to be less frequent when whole brain radiother- apy (WBRT) is combined with surgery or GK radiosurgery, in our experience neither survival nor local recurrence rates improve significantly with WBRT. Advantages of GK over WBRT include brief hospitalization, higher control rates, earlier symptom palliation, all MRI-detected lesions can be treated, other treatments (e.g. radiotherapy) can be postponed, GK-irradiation can be repeated, the incidence of radiation-induced dementia is far lower and more tumors (30+) can be treated in one session. We advocate meticulous MRI follow-up to detect recurrence and assess tumor necrosis. All detectable tumors should be irradiated, in any patient wishes to continue receiving treatment.
Repeated radiosurgery for local recurrences of brain metastases after gamma knife radiosurgery P1-46 Kazuhiro, Yamanaka (1); Yoshiyasu, Iwai (1); Yasuhiro, Matsusaka (1); Kazuhito, Nakamura (1); Toshihiro, Yasui (1); Masaki, Komiyama (1) (1) Osaka City General Hospital - Department of Neurosurgery Osaka, Japan We evaluated the treatment results of repeated radiosurgery for recurrences of brain metastases after gamma knife radiosurgery (GKS). Fifty one patients with 63 brain metastases were treated repeatedly because of recurrent tumors after GKS. The mean age of these patients was 60 (range: 37 - 76). The most common primary site was the lung (76%). The mean tumor volume was 5.9 ml (0.02 - 20.8 ml) and the mean delivered dose to the tumor margin was 19.3 Gy (range: 12 - 25 Gy) in the first GKS. The interval between the first and the second GKS was 9.9 months. In principle, methionine-PET was carried out before repeated GKS. The mean follow up period was 8.2 months (1 - 42 months) after second GKS. The median survival time was 24 months after the first GKS and 12 months after the second GKS. Twenty seven patients died and the causes of death were 8 (30%) brain tumors, 13 (48%) systemic extracranial disease, and 2 (7%) meningeal carcinomatosis. Thirty eight lesions (62%) were controlled after the second GKS and the cumula- tive 50 % control duration was 12 months. Symptomatic radiation injury including transient episodes appeared in 9 (14.8%) patients. Repeated GKS for recurrences of brain metastases after GKS was useful especially for limited survival patients.
Gamma knife radiosurgery for large volume brain metastases: Acceptable volume response rate with marginal increase in toxicity P1-47 C.P., Yu (1); Joel Y. C., Cheung (1); Josie F. K., Chan (2); Samuel, Leung (3); Robert TK, Ho (1) (1) Canossa Hospital - Gamma Knife Center; (2) Canossa Hospital - Gamma Knife Center; (3) Queen Elizabeth Hospital - Department of Neurosurgery Hong Kong, Hong Kong Objective: To analyze the volume response rate and toxicity of large volume brain metastases (LVBM) treated by gamma knife radiosurgery. Methods: We arbitrarily defined LVBMs as lesion(s) larger then 8 cc. We treated LVBMs prospectively with a separate protocol: 18 Gy margin dose with a very high central dose at 45-60 Gy, assuming the more hypoxic and necrotic centre was more radio-resistant. For comparison, we treated the small volume lesions (<8 cc) using a mar- gin dose of 18 Gy with central dose at 36 Gy. We performed sequential MR volume mapping at 228 Poster Abstracts
3 months interval to assess tumor volume response and regular clinical follow up for outcome assessment. Results: Between 1995 and 2004, 137 patients harboring 568 brain metastases underwent gamma knife surgery. We only included those patients with at least 3 MRI follow-ups for this analysis. 68 patients with 316 lesions formed the database of this study. 42 lesions from 31 patients were larger than 8 cc and were treated according to the LVBM protocol. Mean vol- ume of these lesions was 16.9 cc +/- 8.4. During follow up, we observed tumor volume shrink- age in 36 out of 42 (86%) lesions. 28 (66.6%) showed progressive and permanent shrinkage. 8 (19%) developed increase in volume after an initial decrease. 3 of these were local recurrence at 12 months, 23 months, and 36 months, all proven by open surgery. The other 5 were diagnosed as radiation necrosis. In comparison, all small lesions responded with volume shrinkage. 49 (18%) developed radiation necrosis or local recurrence. Median survival of patients harboring LVBM was similar to those with small volume lesions. 6 patients with LVBMs (16 patients with small lesions) survived more than 2 years. Conclusion: Although patients harboring LVBMs are traditionally excluded for radiosurgery, many patients are not candidates for open surgery. gamma knife radiosurgery remains a viable treatment option. 86% of the lesions responded with volume shrinkage (versus 100% for small lesions). Incidences of radiation necrosis plus tumor recurrence were comparable between the LVBMs and small lesions. Survival figures were also similar. gamma knife surgery can be recommended to patients with LVBMs who were unsuitable for open resection, despite a slightly lower response rate when compared to small lesions.
A comparison of Whole Brain Radiation Therapy (WBRT) and radiosurgery (RS) for the treatment of brain metastases: If the volume is prognostic factor influencing survival? P1-48 Edyta, Wolny (1); Aleksandra, Grzadiel (2); Andrzj, Tukiendorf (3); Leszek, Miscyk (1) (1) Center of Oncology-MSC Memorial Institute Branch in Gliwice - Radiotherapy Department; (2) Center of Oncology-MSC Memorial Institute Branch in Gliwice - Treatment Planning Department; (3) Technical University of Opole - Mechanical Faculty Gliwice, Poland PURPOSE: The comparison of radiosurgery and whole brain radiotherapy of patients with brain metastases and evaluation of tumor volume impact on survival. MATERIALS AND METHODS: 155 patients (102 men and 53 women, age 32-81) suffering from brain metastases, treated with WBRT and RS between April 2001 and April 2004. 70 patients were treated with WBRT alone, 61 with RS, and 24 with WBRT and RS boost. The most frequent primary tumor was histologi- cal confirmed lung cancer [96 patients - 62% (55 non-small-cell and 41 small-cell-cancer)], 22 patients (14%) had lung tumor without histological confirmation,18 patients (12%) had non evi- dence of primary tumor,12 patients (8%) suffered from breast cancer and 7 (4%) from renal can- cer. Solitary brain metastases had 33 (21%) and multiple 117 (79%) patients RS was performed using linear accelerator (peripherial dose range was 12-20 Gy) and WBRT was performed using five fractions delivered to total of 20 Gy. The volume of the largest treated lesion varied from 0.5 cm_ to 65 cm_. The performance status in ZUBROD scale was estimated and varied from 0 to 3. RESULTS: The tumor volume increase of about 1cm_ enhanced failure risk of 1,2% (SD 0,54%). The increase in ZUBROD score about one degree enhanced failure risk of 41%.(SD 18%). The estimation of survival time median (weeks) is: 229 Poster Abstracts
for lung tumor: 17.9(SD3.8) - WBRT, 15.8(SD4.2) - RS, 35.4(SD11.4) - WBRT+RS; for lung cancer: 41.1(SD9.8) - WBRT, 35.9(SD9.2) - RS, 81.2(SD 27.6) - WBRT+RS; for breast cancer: 37.8(SD13.9) - WBRT, 32.9(SD12.1) - RS, 74.6(SD32.9) - WBRT+RS; for renal cancer: 42.1(SD20.8) - WBRT, 36.9(SD18.7) - RS, 81.4(SD41.8) - WBRT+RS; for unknown primary site: 32.9(SD10.5) - WBRT, 28.3(SD7.4) - RS, 3.7(SD21.3) - WBRT+RS. CONCLUSION: WBRT in combination with radiosurgery seems to be most effective brain metas- tases treatment modality. Clinical success appears to be dependent on the total intracerebral tumor mass and performance status.
Gamma knife radiosurgery for skull base chordomas: What is an adequate dose level? P1-49 Marc, Goldman (1); Georg, Noren (1); Stephen C., Saris (1); Carla, Bradford (1); Melissa, Remis (1) (1) Rhode Island Hospital, Brown University - New England Gamma Knife Center Providence, USA PURPOSE: Given the critical location and locally aggressive nature of skull base chordomas, they pose a formidable management challenge. Other studies have demonstrated the need to deliver high doses of radiation to affect the growth of chordomas. Gamma knife radiosurgery was used as sole treatment after either subtotal surgical resection or diagnostic biopsy to control the growth. We compared the efficacy of different dose levels in this and other studies. MATERIALS AND METHODS: We evaluated five patients with chordomas who underwent gamma knife radio- surgery as sole adjunct to subtotal surgical resection (three patients) or diagnostic biopsy (two patients). Patient age was 27-57 years (mean 40). The treated tumor volumes were 2.3 to 29.3 cm3 (mean 13.1 cm3) with tumor margin dose range 10-25 Gy (mean 19.2 Gy) and a maximum tumor dose mean of 43 Gy. The follow-up time was 24-84 months (mean 50.4 months). Post radiosurgery tumor volume was calculated from serial MRI imaging performed at regular inter- vals. Patients were seen in follow-up to assess for any focal neurological findings related to either gamma knife treatment or tumor progression. RESULTS: Four patients had stable disease or tumor shrinkage. Only one patient had tumor progression, which was out-of-field. This patient had a prescription dose of 10 Gy to the tumor margin due to proximity of the optic apparatus. Remarkably, this patient also developed cranial nerve deficits. The remaining four patients had a minimum of 20 Gy to the tumor margin and had improvement or no change in pretreatment symptoms. CONCLUSION: Skull base chordomas over a wide range of volumes may be effective- ly treated with gamma knife radiosurgery following biopsy or subtotal resection with low risk of side effects. Precise target definition and planning and a minimum dose of 20 Gy seem to be nec- essary to achieve these results.
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Stereotactic radiosurgery in the management of glomus jugulare tumors P1-50 Francisco, Mascarenhas (1); A, Gonçalves Ferreira (2); H, Carvalho (3); M, Santos (4); A, Almeida (5); M, Vacas (6); M, Sá da Costa (7); S, Germano (8) (1) Hospital de Santa Maria- Lisboa-Portugal - Radiotherapy Dpt; (2) Hospital de Santa Maria- Lisboa-Portugal - Neurosurgery Dpt; (3) Hospital de Santa Maria- Lisboa-Portugal - Neurosurgery Dpt; (4) Hospital de Santa Maria- Lisboa-Portugal - Radiotherapy Dpt; (5) Hospital de Santa Maria- Lisboa-Portugal - Radiology Dpt; (6) Hospital de Santa Maria- Lisboa-Portugal - Neurosurgery Dpt; (7) Hospital de Santa Maria- Lisboa-Portugal - Radiotherapy Dpt; (8) Hospital de Santa Maria- Lisboa-Portugal - Radiotherapy Dpt Lisboa, Portugal ABSTRACT Purpose: This retrospective study evaluate the efficacy and toxicity of stereotactic radiosurgery (SRS) in the management of the glomus jugulare tumors (GTJ). Methods: Fifteen patients were submitted to SRS with a 6 MV linac at the Hospital Santa Maria in Lisbon between July 1997 and February 2005. Median age was 55.4 years (range 30 to 77) of twelve females and three males. Six pts have failed to previous treatment modalities. Reasons to treating with SRS included residual or recurrent tumors after surgery and embolization(6), geriartric/medically unsuitable for surgery (5) and patient preference (4). The tumor volume ranged from 2.3 to 10.4 cc (mean, 6.3 cc). The median marginal dose was 13.8 Gy (range, 12 to 15 Gy) prescribed to 80% isodose line. Results: The median time from date of SRS to the last follow-up was 47.3 months (range 2 to 92 months) including 6 and 9 pts with more than 60 and 36 months respec- tively. Improvement of the symptoms and cranial nerve disfuntions were presented in all patients. After surveillance magnetic imaging eight tumors were reduced and the others were stable being considered a local control in all pts. No acute or late toxicity was documented. Conclusions: Our experience in this series presenting excellent tumor control rate and a favorable toxicity profile support the effectiveness of SRS for patients with glomus jugulare tumors.
Dramatic short term response of tumors of the pineal region to the Gammaknife radiosurgery P1-51 Mazdak, Alikhani (1); Mohammad Ali, Bitaraf (1) (1) Iran Medical Science Of University, Ali Asghar Hospital - Iran Gamma Knife Center Tehran, Iran The optimal management of lesions arising from th pineal region has been a subject of debate.Fifteen cases of pineal region tumors were treated by stereotactic radiosurgery in a 15 months period in Iran gammaknife center . The tumor diagnosis was confirmed by biopsy,tumor markers and MRI imaging.All th patients had a history of increased ICP and V-P shunt insertion.The mean radiation dosage was 20 Gy at 50% isodose.Follow-up data was available for 7 patients at 6 months follow-up period . Five patients had more than 90% decrease in tumor volume and 2 patients had stable tumor size.Six patients experienced an improvement in clinical signs and symptoms.Four patients became symptom free with no neurological deficit. One patient developed intradural seeding of tumor to the spine despite a decrease in tumor size and clinical improvement.Our results indicate that gammaknife radiosurgery might be regarded as an impor- tant treatment modality as adjunct or primary management of pineal region tumors.
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Cyberknife radiosurgery in recurrent head and neck cancer P1-52 Seong Yul, Yoo (1) (1) Radiation Oncology Department Seoul, South Korea Purpose : Locally recurred head and neck cancer after radiation therapy with presentation of gross disease in the field of previous radiotherapy has no effective option of treatment when the sal- vage surgery has limited. In this study cyberknife radiosurgery was used in the treatment of tumors for the palliative aim to remove gross tumor again in expectation of local control. Materials and Methods : Among the 53 patients, a total of 71 sites were treated by radiosurgery at KIRAMS. Squamous cell carcinoma was 59 sites in 41 patients. Distribution of the region was 23 nasopharynx, 15 metastatic neck, 12 paranasal sinuses, 8 oropharynx, 2 parotid and so on. 14 sites received single irradiation with dose of 12 to 23 Gy. 57 sites received 15 to 39 Gy dev- ided by 3 fractions. Median GTV was 18 cm3(0.4 – 457.1 cm3). Results : Median follow-up peri- od is 8 months (3 – 27 months). Including the number of patients showing partial response who alive more than 6 months until the time of evaluation, the total number of response was 44 sites (62.0 %) out of 71. Response rate by site was 73.9 % in nasopharynx (17/23), 86.7 % in metastatic neck (13/15), 66.7 % in PNS (8/12) and 37.5 % in oropharynx (3/8), etc. Response rate by volume was 82.4 % (28/34) when the tumor is smaller than 3 cm in diameter and 37.8 % (14/37) in larger than 3 cm. No difference of response was found between squamous cell car- cinoma and non-squamous cell carcinoma, and between single and 3 fractions treatment. Grade 3 and 4 complication of normal tissue damage was in 2 (4.6%) in responded sites and 6 (21.4%) in non-responded sites. The patients with NED state until now are 17 (32.1%) in number from the total of 53 patients. For the 36 patients failed to be controlled, local recurrence or no response was in 26 (49.0 %), local recurrence and distant metastasis in 1, and distant metastasis only in 5. Conclusion : Radiosurgery is a reliable palliative treatment to the patients who recurred at the site of previous irradiation in head and neck region. Recurrences in the neck and nasopharynx which show the tumor size of less than 3 cm in diameter are good candidate.
Radiosurgery for glomus jugulare: late results P1-53 Vladimir, Zaccariotti (1) (1) Association Against Cancer of Goias - Department of Neurosurgery Goias, Brazil Glomus Jugulare is a slow growing hypervascular tumor with a complex localization that has been treated to date with microsurgery alone or associated with radiation therapy. In the last decade radiosurgery has been employed to control tumor grow. Objective: The objective is to analyze the late results of radiosurgery alone in the treatment of glomus jugulare. Material and Methods: Three patients with complex glomus jugular tumor were submitted to radiosurgery as primary therapy, 2 men and one woman, with 78, 60 and 23 yeas old. The volume of the lesions were 3.06, 4.92 and 19.6 cc. The primary symptoms were pain and there was no cranial nerve dysfunction. The patients received 20, 18 and 16Gy at 90 % isodose line, using a LINAC with conformal shaped bean collimator. Results: All tree patients had important relief of the pain (no more medication necessary) and a follow up of 47, 43 and 53 month showed slight reduction of the lesion in all thee patients. The women developed a new glomus jugular in the contralateral side and were submitted again to radiosurgery. Conclusion: Despite of the small number of cases, 232 Poster Abstracts
long term follow-up showed that radiosurgery is safe and effective control tumor grow and reduce pain associated with glomus jugulare.
Early Experience with a CyberKnife Stereotactic Radiosurgical P1-54 Program Michael, Schulder (1); Brian, Beyerl (1); Richard Hodosh (1); Edward, Zampella (1); Elsbieta, Masur (1); Louis Dchwartz (1) (1) New Jersey Medical School, Newark NJ, Overlook Hospital, Summit NJ Newark, USA INTRODUCTION: We report our neurosurgical experience after a year of Cyberknife radiosurgery (CKR). METHODS: A Cyberknife stereotactic radiosurgery unit (Accuray Inc.) was installed at Overlook Hospital (Summit, NJ) in August 2004. Data were collected retrospectively for all patients with intracranial and spinal tumors that have undergone CKR. Seventy-seven patients with 84 tumors were treated. Diagnoses included 32 patients with metastatic tumors (including 8 in the spine), 16 with acoustic neuromas, 15 with meningiomas and 14 with high grade astro- cytomas. RESULTS: Treatment planning was done using MRI registered to CT scans. The prescrip- tion isodose line ranged from 75% to 85%. Intracranial tumor volumes ranged between 0.058 and 34 cc (median 1.4 cc) with dosing between 1500 and 2500 cGy (median 2000cGy). Spinal tumor volumes ranged between 11 and 99 cc (median 56 cc) with dosing between 1800 and 2500 (mean 2100 cGy). The number of treatment fractions ranged from 1 to 5 for patients with malignant tumors (mean 2.4) and 2 to 5 fractions (mean 4.6) for those with benign lesions. Twenty-seven of the patients with 30 tumors have been followed for more than 6 months (mean of 7 months). Imaging has demonstrated tumor control in 64% of patients with malignant tumors and all with benign tumors. CONCLUSION: We were able to treat patients with a wide variety of intracranial and intraspinal pathology in our first year of CKR, including patients with large tumor volumes. A higher number of fractions were used to treat patients with benign tumors.
Final design, integration and testing of the dedicated proton SRS/SRT beamline at the NPTC P1-55 Marc R, Bussiere (1); Isaac, Mendelson (1); Hanne, Kooy (1); Jay, Flanz (1); Miles, Wagner (1); Bernie, Gotchalk (2); Paul, Chapman (3); Jay, Loeffler (1) (1) Massachusetts General Hospital - Department of Radiation Oncology; (2) Harvard University - Physics Department; (3) Massachusetts General Hospital - Pediatric Neurosurgery Department Boston, USA Since the start of the NPTC clinical operation in November 2001 the demand for treatment slots have gradually increased. Foreseeing further demand for the facility prompted the design of an additional horizontal beamline to be used in conjunction with the proven reliability and precision of the STAR patient positioner. Planning for the new beamline started in October 2002 with an original goal of clinical operation in fall 2004. Design and integration has primarily been done in- house resulting in longer turnaround than anticipated. Design guidelines for the system include: a single scattering system with an SAD of 450 cm, maximum penetration of 20 g•cm-2 and max- imum field radius of 5 cm with dose uniformity of ± 2.5%. The scattering system integrates range and modulation control using a lamination approach. This system is designed with simplicity and robustness in mind. A binary absorber stack provides fine and course steps to achieve flat SOBP. 233 Poster Abstracts
The nozzle incorporates a retractable axial x-ray tube, monitor chambers, light field device as well as a retractable and rotating nozzle. The nozzle provides a mount compatible with either colli- mating cones or the Radionics Inc. mMLC. The integration and testing of the nozzle and scatter- ing system are discussed
Three year radiosurgery experience at the Northeast Proton Therapy Center P1-56 Marc R, Bussiere (1); Hanne, Kooy (1); Paul, Chapman (2); Jay, Loeffler (1) (1) Massachusetts General Hospital - Department of Radiation Oncology; (2) Massachusetts General Hospital - Pediatric Neurosurgery Department Boston, USA Massachusetts General Hospital (MGH) physicians have been treating patients using proton radi- ation therapy since 1961. Until November 2001 proton radiation was delivered at the Harvard Cyclotron Laboratory (HCL). Prior to the transition from the HCL to the Northeast Proton Therapy Center (NPTC) program patient throughput at the Harvard facility were around 24 daily-fraction- ated cases, 5 daily-fractionated ocular cases and an average of two weekly radiosurgery cases. The NPTC treatment day is eight hours with a current throughput of 42 daily-fractionated cases, 5 daily-fractionated ocular cases and one weekly radiosurgery case. The reduction in proton radiosurgery cases has been dictated by the reduction in proton SRS treatments slots due to the high demand for fractionated proton treatments. The MGH is fortunate to have been able to absorb the radiosurgery workload through its Linac based radiosurgery program. The proton radiosurgery program’s current capacity issues will soon be history with the implementation of a dedicated proton SRS/SRT beamline that is currently being commissioned. Despite the reductions in proton radiosurgery cases there have been over 170 patients treated with proton radiosurgery using the gantries at the NPTC. The program’s diagnosis profile is discussed and compared to that of the HCL. Treatments using the NPTC gantry system have provided us with an opportunity to expand on the radiosurgery techniques used at the HCL. Treatment techniques and rational are discussed. A variety radiosurgery cases treated at the NPTC, including some extra-cranial cases are presented. Intra-cranial cases include pituitary adenomas, acoustic neuromas and AVMs. Extra-cranial targets have included solitary lesions contained in the L, T spinal bodies as well as a lung lesion.
History of proton beam radiosurgery P1-57 Mehryar, Mashouf (1); Elham, Bidabadi (2) (1) Guilan university of medical sciences - Department of neurosurgery; (2) Guilan university of medical sci- ences - Pediatric neurology Rasht, IRAN In 1946, Wilson first proposed the clincial use of charged-particle beams because of their unique characteristics. Lars Leksell adressed the theoretical and many practical aspects of stereotactic radiosurgery in 1951.9Using the Uppsala University cyclotron Leksell and Borje Larsson, a radio- biologist, used a cross fired proton beam in intial experiments in animals and in the first treat- ments of human patients. In 1954, John Lawrence began to use the Berkely cyclotron's Bragg peak to irradiate the pituitaries of patients with metastatic breast cancer for hormonal suppres- sion.. In 1961 Raymond Kjellberg began treating patients using the Bragg peak of protons from 234 Poster Abstracts
the Harvard Cyclotron Laboratory. This was soon followed by similar efforts led by V.S. Koroshkov in Moscow. Stereotactic treatment of arteriovenous malformations began in 1963 and was based on a stereotactic guidance device and angiograms.6 Some tumors including skull base lesions could be adequately localized by pneumoencephelography. Leksell performed the first such treat- ment, radiating a vestibular schwannoma in 1969.
Radiosurgery damage probability in target volume. - A proposal for a biological response model P1-58 Vinicio, Toledo-Buenrostro (1); Gabriel, Rodriguez-Hernandez (2) (1) Hospital San Javier - Radiation Oncology; (2) Hospital San Javier - Medical Physics and Radiation Protection Guadalajara, Mexico Introduction Radiosurgery is not commonly used as a fractionated modality in the treatment of intracranial lesions, some experience is emerging in relation to fractionation in various types of intracranial lesions and had been reported, however the lack of statistically significant morbidity information limits the widening of the practice outside of clinical trials. Material and methods Cell death mechanisms and predictive assays were reviewed before mathematically modeling late tox- icity for fractionated radiosurgery. As had been referred the effect is dose-volume dependent and hierarchical and non hierarchical tissues had different latency period for functional and morpho- logical changes. We assumed then these variables can predict end point tissue toxicity. Dp = [(df/v) á/â ] / N / i Damage probability (Dp), df (dose per fraction), v (volume), á/â (alfa/beta ratio from QLM), N (number of fractions administred) and i (interval between fractions). Hypothesis Radiation induced damage probability in gross tumor volumes and his surrounding tissues in radiosurgery could be higher than estimated in most clinical settings, with equal volumes and equal conformal index, for fractionated radiosurgery there should be a minor probability of toxi- city than one fraction radiosurgery. Assuming for healthy tumor surrounding tissues á/â ratio to be equal to 3 (1 to 6, late responding tissues) and 10 for tumor cells (early responding). The model compares one fraction radiosurgery with fractionated treatments. No equivalent dose response has been developed in interfractionation schemes between single, two and three frac- tions, tables for Biological Equivalent Dose in damage probability in alfa/beta ratio 3 and 10 were developed following our proposal for comparison. Conclusion The dose standardization is the goal in whatever instrumentation and technique are applied, mathematical models simplifies the decision making process in identified benign intracranial diseases to be treated with RS. We assume Dp model can be appied and clinically correlate with outcome in patients, results will encourage investigation in valid clinical settings for developing intercomparative treatment schemes in one and multiple fraction radiation administration with radiosurgery.
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Distal region cephalothorax map of Crayfish Procambarus clarkii. Magnetic resonance atlas for experimental gamma radiosurgery P1-59 Daniel Salvador, Ruiz Gonzalez (1); Ramiro, Del Valle (1); Salvador, Ponce de Leon (1); M.P., Torres Garcia (2); J.L., Bortolini Rosales (3); Manuel, Martinez Lopez (1); L., Mendoza Vargas (4); E, Muñoz Mancilla (5); Miguel, Perez Pastenes (1); JA., Viccon Pale (7) (1) Medica Sur SA de CV MSU 820125 T58 - Unidad Gamma Knife; (2) University National of Mexico - Invertebrate Laboratory; (3) University National of Mexico - Invertebrate Laboratory; (4) Metropolitan Autonomous University. Mexico - Temporal Structures in Functional Crustaces Mexico, Mexico Uncoupling of the present circadian rhythm in pairs organs has been an effective instrument to obtain information about its behavior. In the crayfish of genus Procambarus the possibility has been opened to obtain this uncoupling in the circadian rhythm of the chelipeds motor activity, by means of the gamma surgery in one of the protocerebrum hemiganglia. By that, it was necessary to pre- viously establish the histological map and magnetic resonance of the distal region cephalothorax was selected as a target. In order to obtain the map with resonance: crayfish at time to be immo- bilized for its cephalothorax using stereotactic device for radiation and this one introduced to the resonance camera (Sigma eco-speed, Platform 9.1, teslas 1.5), were obtained from the stereotac- tic atlas in two sequences of axial cuts, T1 and T2. After, these images were amplified to 200 µm and it shows a map and is compared with the obtained one through conventional histology.
Distal region cephalothorax map of Crayfish Procambarus clarkii. Cerebroid ganglion and adjacent structures histological map: basic model for gamma radiosurgery P1-60 Ramiro, Del Valle (1); Daniel Salvador, Ruiz Gonzalez (1); Salvador, De Anda Ponce de Leon (1); Miguel, Perez Pastenes (1); M.P., Torres Garcia (2); J.L., Bortolini Rosales (3); E, Muñoz Mancilla (6); Manuel, Martinez Lopez (1); L., Mendoza Vargas (4); JA., Viccon Pale (9); Juan, Ortiz Retana (1) (1) Medica Sur SA de CV MSU 820125 T58 - Unidad Gamma Knife; (2) University National of Mexico - Invertebrate Laboratory; (3) University National of Mexico - Invertebrate Laboratory; (4) Metropolitan Autonomous University. Mexico - Temporal Structures in Functional Crustaces Mexico, Mexico Astacid´s central nervous system, is compound of a cerebroid ganglion and paired longitudinal ventral nerve cord, under digestive tract, in the cephalothoracic region, connected to the sube- sophageal ganglion. Anatomical differences exist with other species of decapods like the acces- sory lobes, that in Procambarus they are the bigger structures in the central nervous system and recognized like the centers of sensorial integration. Of there the importance to know the anato- my and histology these structures to understand roll that plays within all the organization of the nervous system. Objective of this research is to establish the normal histological frame of the cere- broid ganglion and adjacent structures of P. clarkii. Adult organisms were fixed with Davidson´s and RF´s solutions by 48-72 hours, later were dissected and including in paraffin (56-58 °C melt- ing point), obtaining cross and longitudinal sections with a 7 µm thickness of cerebroid ganglion region. Slides were stained by Hematoxylin-Eosin, Lendrum, Mallory and Masson techniques. The different cellular types were observed that they conform to nervous system in the anterior region of cephalothorax and adjacent tissues. Photomicrographs on light field was taken in Microscope Olympus Provis AX70. 236 Poster Abstracts
Modulation of dose rate effects to minimize normal neural tissue toxicity while maximizing tumor control probability P1-61 Steven, Howard (1); James, Welch (1); Ian, Robbins (2); Wolfgang, Tome (1) (1) University of Wisconsin Medical School - Human Oncology Department; (2) University of Wisconsin Medical School - Medical Oncology Madison, USA Radiotherapy delivered below standard dose-rates reduces normal tissue toxicity and can induce significant tumor regression in some tumor types but not others. Early clinical studies suggested that fractionated reduced dose-rate external beam radiotherapy can achieve an improved thera- peutic ratio. The factors and mechanisms that determine the response of normal cells and tumors to low dose-rate irradiation remain largely unknown. In conventional radiotherapy a dose of 2 Gy is delivered at a dose rate of 4-6 Gy/min, which means that the delivery of this dose requires only a few minutes. By reducing the effective dose-rate and increasing the treatment time, it becomes possible for repair processes to be active during irradiation. This reduction in dose-rate can result in a therapeutic advantage because repair of sub-lethal damage is greater for late complications than for tumors and there may be some accumulation of tumor cells in a sensitive phase of the cell cycle such as G2. A low dose-rate can either be obtained by using a continuous low dose- rate irradiator which is economically not very feasible, or by dividing the standard 2 Gy fraction into a number of equal sub-fractions that are delivered in a pulsed manner separated by a fixed time interval. Thus, allowing for repair during each sub-fraction. This pulsed approach will pref- erentially protect normal tissue and have almost the same effect in terms of tumor cell kill because repair capacity is greater in late responding normal tissues than tumors. We have developed model-based methodology using reduced dose-rate external beam radiotherapy in the re-treat- ment of recurrent glioma patients that have received prior radiotherapy. Re-treatment will be delivered using daily 2 Gy fractions administered in 20 cGy pulses at a dose rate of 100 MU/min every three minutes for a time averaged dose-rate of 6.67 cGy/min. The model, its background, clinical implementation and preliminary clinical results will be discussed.
Vascular changes in the rat middle cerebral artery after Gamma Knife irradiation (preliminary results) P1-62 José, Lorenzoni (1); Gyorgy, Szeifert (2); Isabelle, Salmon (3); Françoise, Desmedt (1); Jacques, Brotchi (4); Marc, Levivier (1) (1) Hôpital Erasme - Centre Gamme Knife; (2) National Institute of Neurosurgery - Department of Neurosurgery; (3) Hôpital Erasme - Department of Pathology; (4) Hôpital Erasme - Neurochirurgie Brussels, Belgium Purpose: To study the effect of a single dose of gamma irradiation in a great intracranial vessel in rats at different doses and intervals. Material & Methods: 125 male Wistar rats were irradiated in a gamma knife using a stereotactic frame designed for small animals. The target was the right middle cerebral artery and coordinates were calculated according to Paxinos rat brain atlas. Doses delivered to the artery were 15, 30, 50, 70, 90, 120 and 160 Gy. And rats were sacrificed at 24 hours, 7 days, 21 days, 2 months, 6 months, 1 and 2 years. Others non irradiated rats served as controls. Basic staining were used, as well as specific ones for endothelial layer, smooth muscle cells, fibroblasts, and apoptosis. Results: Vasoconstriction was detected at 24 hours until 7 days; this phenomenon affected in a diffuse way the vessels of the polygon and was observed even at 237 Poster Abstracts
low doses. In a second step there was a damage of the endothelium that was dose dependent and finally appeared changes in the vessel wall. Apoptotic markers were employed trying to cor- relate apoptosis induction by radiation and structural changes observed. Conclusions: Radiosurgery is able to induce changes in great intracranial vessels in rats. Most of these changes seem to be dose and time dependent. This animal model could be useful in estimating vascular risk in radiosurgical treatments, especially those using high dose irradiation.
Comparison of late radiobiological effect of the brachytherapy and LINAC radiosurgery modalities on the normal brain tissue P1-63 Arpad, Viola (1); Jeno, Julow (1); Tibor, Major (2) (1) St. John's Hospital Budapest, Hungary - Department of Neurosurgery; (2) National Institute of Oncology and Radiation Therapy, Budapest, Hungary - Department of Radiation Therapy Budapest, Hungary Purpose: The goal of this study was the comparison of the dose distributions, the radiological effi- ciency of 125 Iodine brachytherapy and the LINAC radiosurgical procedure. Methods and mate- rials: For the irradiation of the 37 brain tumors we prepared plans of 125 Iodine brachytherapy and plans for LINAC radiosurgical irradiation. For each of the brachytherapy plans, we determined the amount of normal tissue in relation to a given percentage of the target volume, which received doses of 8, 12, 20-100 Gy. For the equivalent volumes, we found dose values referenced back to the LINAC plan. We recounted the LINAC doses into brachytherapy doses according to the dose-time formula of the linear quadratic (LQ) model. We attributed two brachytherapy doses to each volumetric value, this gave a comparison of late radiobiological effect of the brachyther- apy and LINAC plans on the normal tissue. Results: At higher doses brachytherapy is significant- ly more advantageous regarding the normal tissues than LINAC irradiation. Better conformality has been achieved at the plans for brachytherapy than at the plans for LINAC irradiation, with no significant difference. In dose homogeneity, LINAC has proved to be significantly better than brachytherapy (p<0.01). Conclusion: In order to achieve a balance between better tumor control and protection of the normal tissues, the comparison of the results of stereotactical irradiation methods may be useful.
Treatment of acoustic neurinoma with stereotactic radiosurgery P1-64 Leoncio, Arribas Alpuente (1); ML, Chust (1); A, Menendez (1); V, Crispin (1); JL, Guinot (1); JL, Mengual (1); PP, Escolar (1) (1) Instituto Valenciano de Oncología - Radiation Oncology Valencia, Spain Acoustic neurinoma is a benign tumor arising from Schwann cells, usually located in the vestibu- lar portion of the vestibulocochlear nerve. Surgery has been the classical treatment but, despite the advances developed recently in surgical approaches, a significant rate of complications per- sits for a majority of patients. Radiosurgery has been used during last years as an effective and non invasive treatment for small and medium sized acoustic neuromas achieving an excellent local control with less complications than surgery .We analize retrospectively patients with diag- nosis of acoustic neuroma treated with stereotactic radiosurgery in our deparment. Methods and materials Since February 1998 to October 2003, the treatment of 86 patients was revised ( medi- an follow-up 51 months ; range 13-87 ). All of them have been diagnosed according to MRI and 238 Poster Abstracts
CT images and audiogram. Thirty- five patients were men and fifty-one women with a median age of 65 years old ( range 19 – 87 ). Unilateral hearing loss was the most common symptom followed by tinnitus and dizziness. Radiological images showed that the tumor was intracanalic- ular in 14 patients, in 65 had both intracanalicular and cerebellopontine angle components, in 4 patients tumor was cystic and in 3 we had to make an angiography in order to differenciate from meningioma. Pretreatment clinical hearing evaluation was performed according to Gardner- Robertson classification: class I, 4 patients; class II, 23; class III, 23; class IV, 6; class V, 15. Facial neuropathy was also evaluated ( House- Brackmann ): minimal 6 patients; moderate 4 and palsy in 1 patient. Five patients had trigeminal neuropathy ( decrease sensation or paresthesias ). Fourteen patients had hydrocephalus before treatment with stereotactic radiosurgery and five of them needed surgical derivation. Radiosurgery was the first treatment in 74 patients; in eleven patients surgery was previously performed and one patient received external beam radiotherapy and radiosurgery. We used Professor Barcia-Salorio’s stereotactic frame. MRI and CT were per- formed to determinate radiosurgery target volume. Planning was made with PLATO 3D LINE sys- tem. Treatment was delivered in LINAC , 6 Mv photons using a noncoplanar multiple arcs tech- nique witn circular collimators. The median dose at isocenter was 18 Gy ( range 9 Gy- 30 Gy ); median marginal dose 12 Gy (range 6 Gy- 16 Gy); median isodose prescription 80% ( range 40%- 100%). Results Forty-seven patients remained with stable desease; 31 showed tumor size decreased and in four patients complete response was achieved. Three patients experienced enlargement of tumor sie. Absolute local control was 96.4%. Five years actuarial local control was 95%. Two out of three patients who failed to radiosurgery recieved salvage surgery achieving ultimate local control. In the third patient a second radiosurgery was performed with tumor pro- gression 9 months later, receiving than salvage surgery. Acute complications: two patients devel- oped transient trigeminal neuropathy , one minimal transient facial neuropathy and 1 patient headache. Cronic complications: four patients developed LCR cyst and in two of them surgery was required. Seven patients presented hydrocephalus . Treatment with derivation was per- formed in three of them. Postreatment hearing evaluation was made in 48 patients: 16 / 23 with grade I-II previous to radiosurgery (69%) and 13/25 with previous level III / IV (20%) remained stable or improved their functional level. Conclusion Streotactic radiosurgery achieve a rate of local control with a low rate of complications and a high probability of preserving functional hear- ing. We have more incidence of cyst an hydrocephalus than is reported in the literature perhaps because in almost fifty per cent of this patients the tumor size was greater than 3 cm and they were older than 70.
Vestibular schwannomas (VS): intracanalicular extension and associated hearing loss. Volumetric analyses P1-65 Ouzi, Nissim (1); Nicolas, Massager (2); Carine, Delbrouck (3); Philippe, David (4); Daniel, Devriendt (5); Françoise, Desmedt (1); Jacques, Brotchi (2); Marc, Levivier (1) (1) Hôpital Erasme - Centre Gamme Knife; (2) Hôpital Erasme - Neurochirurgie; (3) Hôpital Erasme - Centre Gamme Knife; (4) Hôpital Erasme - Neuroradiologie; (5) Institut J. Bordet - Radiothérapie Brussels, Belgium Introduction: While tumor size affects the ability to achieve hearing preservation during micro- surgery for VS, no clear association exists between tumor size and the degree of hearing loss (HL). It has been previously reported that parameters related to internal acoustic canal (IAC) extension 239 Poster Abstracts
are predictors of severity of hearing deficit, but in their analyses investigators have largely relied on two dimensional measurement of tumor size. Utilizing our gamma knife (GK) workstation for VS treatment planning, considerable inter-individual variability in the shape of the IAC was observed. With the capability to define and measure IAC bony and tumor volumes we attempted to identify predictors of degree of HL. Methods; Between 2000-2005, 150 patients with VS were treated at our GK center. There were 57 females and 93 males aged 11 to 89 (median 55) years. Prior to treatment, Gardner Robertson class (GRc) scores were evaluated and patients underwent computed tomography (CT) and magnetic resonance (MR) imaging (T1 with and without gadolin- ium and T2, 1 mm contiguous sequences). There were 33% GRc I, 23% GRc II, 20% GRc III, 2% GRc IV and 22% GRc V patients.Using the workstation software, intra and extracanalicular tumor and bony IAC volumes and dimensions were measured and the IAC tumor to canal volume ratio was calculated. Results; Tumor volume ranged from 46-8300 (median 1100) mm3 . The intra- canalicular component measured 22-732 (median 174.5) mm3 and the canal volume was 110- 862 (median 243) mm3. The canalicular tumor to canal ratio ranged from 0.15-1.0 (median 0.79). Preliminary analysis suggests an association between Grc and canalicular tumor/canal volume ratio and not with absolute tumor volumes. Conclusion; The results suggest that in considering disease progression and the possible adverse effects VS have on hearing, relative intracanalicular tumor size and growth rather than absolute tumor size should be evaluated.
Radiosurgery of cerebellopontine angle tumors. Optimization of treatment and outcomes evaluation P1-66 Yaroslav, Parpaley (1); Miron, Sramka (1); Augustin, Durkovsky (2) (1) St. Elisabeth Cancer Institute - Department of Radiosurgery; (2) St. Elisabeth Cancer Institute - Department of Radiology Bratislava, Slovakia Statement of study purpose Radiosurgery of cerebellopontine angle tumors during last 10 years is using strict dose parameters, showing good results in tumor control and neurological deficit pre- vention in multiple studies. However further improvement of planning, precise evaluation of tumor changes as also tracing cranial nerve function are needed. Methods After tumor and brainstem 3D visualization we did planning with surface dose 12-14 Gy (70%-80% of maximum) and conform- ity factor 1,2-1,8. We use 2 to 6 ovoid isocenters, control dose at risk structures and maximum dose location. For evaluation of tumor control we use volumetric study with full tumor contouring on T1 2 mm MRI scans 6 months and annually after radiosurgery, fused with MRI from planning. For evaluation of V, VII and VII cranial nerves function we used questionnaire based on House- Brackman and Gardner-Robertson scales, clinical neurological investigation, audiometry and elec- tromyography. Results We evaluated patients after LINAC radiosurgery on our institution from 1993 to 2005 with acoustic neuromas (79) and cerebellopontine meningiomas (76). Mean fol- low-up 56 months. Clinical results was evaluated by 56 patients with acoustic neuromas and 36 patients with meningiomas with 52 monts mean follow-up. Tumor control rate is 93,8% by neu- romas and 84,5% by meningiomas. Hearing preservation rate was 92,7% and facial nerve preser- vation 94,5%. Cases with postoperative facial nerve neuropathy and hearing loss correlated with higher maximum dose in tumor tissue. Tinnitus appeared in 4% of patients, trigeminal neuralgia n. V. in 2% of cases. Conclusions LINAC radiosurgery of common cerebellopontine angle tumors is providing high percent of tumor control by rare cranial nerve complications also by long-term 240 Poster Abstracts
evaluation. Improvement of planning technique and automated isocenter positioning opens new horizons for LINAC radiosurgery with cylindrical collimators. 3D volumetric study is precise tool for tumor control evaluation giving early information about continuing growth of tumor.
Gamma knife radiosurgery for vestibular schwannomas P1-67 Selcuk, Peker (1); Turker, Kilic (1); Meric, Sengoz (2); Necmettin, Pamir (1) (1) Marmara University School of Medicine - Department of Neurosurgery; (2) Marmara University - Radiation Oncology Istanbul, Turkey The aim of this study is to evaluate the efficacy of gamma knife radiosurgery on vestibular schwan- nomas. We reviewed the records of 110 patients with more than 2 years of follow-up. There were 61 (55%) female and 49 (45%) male with median age 49. Mean volume of the tumours was 7.3 cc. Mean marginal dose to the tumor was 12.96 Gy. In 12 patients there were no hearing before gamma knife treatment. In 30 (33%) patients the hearing level was decreased after treatment. Only 1 patient had temporary facial paresis. The tumor growth control rate was found to be 98%. gamma knife radiosurgery is an effective treatment for vestibular schwannomas.
Limitation of size for the radiosurgical treatment of vestibular schwannomas.Comparison between 2D and 3D informations P1-68 Pierre-Hugues, Roche (1); Jean, Regis (2) (1) CHU La Timone - neurochirurgie; (2) CHU La Timone - Service de Neurochirurgie Marseille, France When managing vestibular schwannomas (VS), tumor size is an important limitation for the radio- surgical treatment. Considering that each posterior fossa is of individual morphology, the relation- ship between the tumor volume (TV) and posterior fossa volume (PFV) is a relevant parameter to individually evaluate the tumor mass effect. Stereotactic fused CISS MR and CT scan images were obtained from 58 adult patients harbouring an unilateral VS. Tumors were classified as Koos II in 25, Koos III in 21 and Koos IV in 12 cases. Using a Gammaplan working station, the following parameters were screened: intracisternal anteroposterior, transverse, craniocaudal and maximum diameters of the VS. The computarized TV, the parenchymal volume, the cisternal volume were also calculated. Correlations between the actual tumor volume and the tumor diameters were assessed with the Spearman’s correlation coefficient. The prediction of brain compression follow- ing the aforementioned measured parameters was studied using the ROC anlysis. The simplest method to approximate the tumor volume was the maximum intracisternal diameter of the VS (Spearman’s Rho = 0.94). The simplest measurement to predict the brain compression was the transverse intracisternal tumor diameter. Using a 80% threshold value for the sensitivity and specificity, neuroagressiveness could be predicted for a TV cut-off value of more than 1997 cubic millimeters, and for a more than 14.5 mm transverse diameter cut-off value. This study indicates that sophisticated 3D measures like the ratio TV/PFV are not more accurate to predict brain shift than the intracisternal transverse diameter of the VS. Since it is our believe that radiosurgical treat- ment is not the first stair option for large VS, these study provide quantitative informations regard- ing the limitation of tumor size for the gamma knife radiosurgical treatment.
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Linac radiosurgery for acoustic neuromas: experience at the CHU of Liège P1-69 Isabelle, Rutten (1); Bruno, Kaschten (2); Snezana, Kotolenko (3); Achille, Stevenaert (2); Jean-Marie, Deneufbourg (1) (1) CHU Liège - Radiothérapie; (2) CHU Liège - Neurochirurgie; (3) C.H. de Luxembourg - Radiotherapy Liège, Belgium We present a retrospective analysis of the results of linac radiosurgery performed on 27 patients with an acoustic neuroma between 1995 and 2001. We focused on tumour control, preservation of hearing, and of function of trigeminal and facial nerves. The median follow-up was 51 months (range 16-96 months). Only evolutive tumours were treated. Their median size was 18 mm (range 9-30 mm). Patients were immobilized with a BRW model headframe. Treatment planning was performed with a Radionics X-knife v. 4. An arc technique was used with a 6 MV Linac. Single doses were 12-14 Gy at the 80% isodose. Results can be summarized as follows.
Early detection of tiny vestibular schwannoma by FIESTA MR Images and treated with gamma knife radiosurgery P1-70 Chain-Fa, Su (1); Tzu-Wen, Loh (1); Chou Chin, Lee (2); Wen-Lin, Hsu (3); Shinn-Zong, Lin (1) (1) Buddhist Tzu-Chi Medical Center, Tzu-Chi University - Department of Neurosurgery; (2) Buddhist Tzu-Chi Medical Center, Tzu-Chi University - Department of Radiology; (3) Buddhist Tzu-Chi Medical Center, Tzu-Chi University - Department of Radiation Oncology Hualien, Taiwan Purpose: Gamma knife radiosurgery (GKRS) has been proven as an effective treatment for vestibu- lar schwannoma less than 3 cm in diameter. In addition, Fast Imaging Employing STeady-state Acquisition (FIESTA) image of brain MR can present the fine anatomical structures in the internal acoustic canal without contrast enhancement. We report our preliminary experience in GKRS after early detection of tiny vestibular schwannoma by FIESTA MR images. Materials and Methods: Between January and December of 2004, FIESTA images were routinely added to all patients for MR study of brain in Tzu-Chi Medical Center, Hualien, Taiwan. Sixteen patients (11 women and 5 men, age ranged from 45 to 85 years with a mean of 61) were diagnosed as tiny vestibular schwannoma (less than 0.5 c.c. in tumor volume). Tumors were calculated between 0.013 c.c. and 0.4 c.c. with a median volume of 0.155 c.c. Fourteen patients had serviceable hearing before GKRS. In GKRS, only 4 mm collimators were used. The median marginal dose was 12.5 Gy (range: 11-14) at an isodose line 50-70 %. Results: In this short-term follow-up (mean 8.9 mos, range: 3.9-15.6 mos), no tumor progression, no hearing deterioration and no new cranial neuropathy could be detected. Conclusions: With the application of FIESTA image, tiny vestibular schwanno- ma can be early detected. Because the low dose (12-14 Gy) GKRS was proven to be effective for long-term control of tumor with preservation of hearing function, it is worthy to use FIESTA to detect the tiny vestibular schwannoma and treated by GKRS. Long-term follow up is still needed.
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Wednesday 14/09/05
POSTER SESSION 2 10h30 - 11h30
PHYSICS, MOLECULAR IMAGING, MENINGIOMAS, FUNCTIONAL RADIOSURGERY, SPINAL RADIOSURGERY, PITUITARY TUMORS
Stereotactic neurosurgery for central pain P2-1 Yong-sheng, Hu (1); Yong-Jie, Li (2) (1) Beijing Xuanwu Hospital - Department of Functional Neurosurgery, Xuan Wu Hospital, Capital University of Medical Sciences; (2) Beijing Xuanwu Hospital - Department of Functional Neurosurgery, Xuan Wu Hospital, Capital University of Medical Sciences Beijing, China Objective: A study on Stereotactic Neurosurgery for the treatment of central pain. Methods: 12 patients with central pain have been investigated clinically including 6 cases of thalamus or pon- tine infarction, 2 cases of thalamus haemorrhage, one case of thalamus necrosis and 3 cases of spinal pathology. The mesencephalotomy and bilateral anterior cingulotomy was co-performed in 8 patients with central pain. Other targets included the mesencephalon tract, the ventralis pos- terolateralis nucleus of thalamus (VPL) and the cingulate gyrus respectively. The visual analog scale (VAS) and the McGill pain questionnaire (MPQ) were evaluated for preoperative and post- operative pain status of each patient. The visual analog scale (VAS) and the McGill pain question- naire (MPQ) were used for preoperative and postoperative evaluation of the pain status of each patient. Statistical analyses were conducted using paired-samples t test. Results: The short-term (1 month) follow-up results indicated a significant reduction in patients’ pain scales (p<0.05). The daily narcotic dosage of all patients decreased obviously. In the long-term follow-up period, the relieve pain effect of the co-operation of mesencephalotomy and bilateral anterior cinguloto- my was better than the lesion of mesencephalon, the ventralis posterolateralis nucleus of thala- mus and the cingulate gyrus respectively. There were no serious complication and surgery-relat- ed mortality. Conclusion: Stereotactic neurosurgery procedure is effective in relieving central pain. The co-operation of mesencephalotomy and bilateral anterior cingulotomy is more beneficial to the patients with central pain.
Cyberknife radiosurgery for hypothalamic harmatoma in patient with medically intractable epilepsy and precocious puberty P2-2 Kyung Jin, Lee (1); Kyung-Sool, Jang (2) (1) St Mary's Hospital - Department of Neurosurgery; (2) St.Mary's hospital - Neurosurgery Seoul, Republic of Korea Background: hypothalamic harmatoma represent well-known cause of central precocious puber- ty and gelastic epilepsy. Although Conventional microsurgical resection is used in hypothalamic harmatoma, often associated with morbidity. In this case present, cyberknife radiosurgery was applied as a safe and noninvasive to obtain seizure control. Methods : A 6-year-old boy present- 243 Poster Abstracts
ed with medically intractable gelastic epilepsy and increased episodes of secondary generalized seizures. Abnormal violent behavior and precocious puberty were also presented. Magnetic res- onance imaging of brain revealed hypothalamic harmatoma measured 10 and 12mm. Cyberknife radiosurgical treatment was performed with marginal dose of 14 Gy 73 % of isodose areas. Results : After follow-up periods of 6 months, progressive decreased in both seizure frequency and intensity was noted. After 10 months, seizure was disappeared. This patient was able to learn. Follow-up Magnetic resonance imaging has slight decresed changes in size of the lesions. Conclusions : Cyberknife radiosurgery can be an more effective and safe than conventional micro- surgery for achieving good seizure control in patient with hypothalamic harmatoma.
LINAC radiosurgery for hypothalamic hamartoma epilepsy P2-3 Vladimir, Zaccariotti (1) (1) Association Against Cancer of Goias - Department of Neurosurgery Goias, Brazil Radiosurgery for the treatment of hypothalamic hamartoma epilepsy has achieved very good results with low rate of complications in the literature. At our institution we performed radio- surgery in three patients with classical epilepsy secondary to hypothalamic hamartoma. To achieve the best dose distribution, according to the structure of the lesion, using a LINAC, con- ventional or shaped beam collimator was used. Objective: Describe three cases of LINAC radio- surgery for hypothalamic hamartoma epilepsy. Material and Methods: Three male patients, 3, 8 and 21 years, with medically untreated epilepsy secondary to hypothalamic hamartoma, and daily typical gelastic, were submitted to LINAC radiosurgery. The fist and the second patients were previously operated with partial resection and showed no change in the epilepsy profile. Results: After four months a remarkable reduction on the number of crisis was noted on all three patients. At the end of the 8th, until the 30th follow-up month, complete control of the epilepsy was achieved on the fist patient, with no more medications. The second and the third patients with a follow up of 22 and 12 months still present rare seizure, less then one per month. There was no neurological deficit secondary to radiosurgery. Conclusion: Hypothalamic hamartoma epilepsy can be successfully treated with LINAC radiosurgery.
Gamma knife radiosurgery for intracranial meningiomas: Relationship between shrinkage and symptom relief P2-4 Jeremy, Ganz (1); Amr, El Shehaby (1); Hafez, Ayman (1) (1) Cairo Nasser Institute - Gamma Knife Center Cairo, Egypt Objective: It is a common assumption that clinical relief following radiosurgery accompanies tumour shrinkage. A prospective study was undertaken to see if this assumption was valid. Materials and methods: From June 2001, 151 consecutive patients underwent gamma knife Surgery (GKS) for a total of 163 meningiomas. The mean follow up has been 13.4 months (range 3 to 36 months). One hundred and twenty-seven tumours (84%) were basal and 24 (16%) were non basal. The commonest location for basal meningiomas was in and around the cavernous sinus (43%). The commonest location for non-basal meningiomas was parasagittal (50%). The mean age was 49 years (range 20 to 75 years). The male : female ratio was 1:3. The prescrip- tion dose used was 12 Gy for all cases except three. The mean tumour volume was 9.5 cm3 (range 244 Poster Abstracts
0.58 - 43.2 cm3). The mean conformity index was 1.15. The mean prescription isodose was 48% (range 30% to 75%). The mean percentage cover was 90% (range 54 to 100%). A cover of less than 90% was used in 22 patients in 21 of whom it was used to protect vision. Results: The var- ious ways of defining shrinkage are also discussed. Clinical improvement was significantly relat- ed to tumour shrinkage (p<0.0005). However 40% of tumours which had not shrunk demon- strated clinical improvement, Almost all the symptoms which improved were related to basal meningiomas. There were changes of visual function in 13 patients. In 11 it improved and in two there was deterioration. Diplopia improved in 22 patients and was unchanged in 11. Headache improved in 15 patients and was unchanged in 5. Three patients had tumour swelling with tem- porary neurological deficit which was easily managed with dexamethasone with no permanent sequelae. Epilepsy was present in 9 basal and 11 non basal locations. Improvement of the epilep- sy had no relation to location or previous surgery. The most usual factor associated with lack of improvement following GKS was the patient not taking the medication as instructed (p < 0.01). The mean follow up of tumours which have shrunk was 17 months while for this which had not it was 12.4 months (p < 0.005). Conclusion: The findings are in keeping with those published elsewhere. However, there are three interesting new observations. Clinical improvement can occur without tumour shrinkage in a fair number of patients. Reduction in volume seems to begin consistently after about 15 months. Lack of improvement of epilepsy may often be due to the patients’ mismanagement of their medication. This should be considered when the effects of any treatment are measured against epilepsy control.
A prospective multicenter study about tumor volume reduction after stereotactic radiotherapy of skull base meningiomas P2-5 Martin, Henzel (1); Markus W, Gross (1); Klaus, Hamm (2); Gunnar, Surber (3); Gabriele, Kleinert (3); Gerd, Strassmann (1); Rita, Engenhart-Cabillic (3) (1) Philipps University Marburg, Germany - Dept. of Radiation Oncology; (2) Helios Klinikum Erfurt, Germany - Dept. for Stereotactic Neurosurgery and Radiosurgery; (3) Philipps University Marburg - Radiotherapy and Radiooncology Department Marburg, Germany Introduction: Fractionated stereotactic radiotherapy (SRT) is well established in the treatment of skull base meningiomas. Data for radiological regression are very heterogenous according to dif- ferent definitions. Therefore, aims of this prospective study are to analyse tumor volume (TV) shrinkage and to calculate determinant factors. Methods: 94 patients suffering from a WHO I° meningioma were examined under equal conditions before and every 6 months after SRT. Fat sat- urated axial T1-weighted contrast-enhanced MRI scans with a 1-3 mm slice thickness were used. After image fusion TV was drawn in each slice for analysing TV shrinkage 3-dimensionally by the planning system. Prognostic factors like histological subtypes, prescribed dosis, age, gender, pre- operations and initial TV were calculated. Results: Initially the mean TV was 12.8 ml (median 8.5 ml). A decreasing mean TV shrinkage was seen 6, 12, 18 and 24 months after SRT: 18.1% (p<0.0001), 26.2% (p<0.0001), 30.3% (p<0.0001) and 39.4% (p=0.05). Patients younger/older than 55 years revealed a significant mean shrinkage of 29.7%/20.0% (p<0.05). Smaller TV tented to an increased shrinkage: TV < 8.5 ml 26.5% and TV >8.5 ml 23.7% shrink- age (p=0.11). There was no correlation between TV shrinkage vs. improvement of the symptoms, vs. prescribed dosis vs. histological subtypes. Conclusion: SRT is a very effective method for the 245 Poster Abstracts
treatment of skull base meningiomas. More than 30% TV shrinkage is seen 2 years after irradia- tion. Younger age and previous operations are determinant factors. Smaller TV and females tent to an increased shrinkage. Prescribed dosis or histological subtypes do not affect TV shrinkage.
Fractionated stereotatic radiotherapy of base of skull meningiomas: a preliminary comparison in the delineation of the gross target volume between 4 medical specialities P2-6 Carine, Mitine (1); Laurent, Gilbeau (2); Frederic, Dessy (2); Christelle, Pirson (2); Jean-Francois, Rosier (2); Marie-Therese, Hoornaert (2); Ludovic, Harzee (2); Anne, Doneux (2) (1) Jolimont hospital - Radiotherapy; (2) Hôpital de Jolimont - Radiotherapie Haine St Paul, Belgium Purpose: To study the interobserver variability of base of skull meningiomas delineation on com- puted tomography. Methods and materials: A group of 8 physicians working in the same centre (2 neurosurgeons, 2 neuroradiologists, 2 radiation oncologists and 2 medical oncologists) were asked to delineate the gross tumour volume of two patients on sequential CT slices. All observers were provided with the same clinical information. Results of the delineation by the 4 specialities are compared to each other. The mean of the volumes delineated by all observers are calculated. To determine the variation in the anatomical position of the target volume, a 3D comparison between an arbitrary point determined in the tumour and the most distant point of the tumour in the three directions. For the interobserver variability, the coefficient of variance is used. Results: Large differences are observed between the 8 physicians both for the estimation of the tumour volume and its anatomical position: the ratio of the largest to the smallest defined volumes varies by factors 8.8 for the first patient and 3.3 for the second. This ratio becomes 1.19-1.66 for the medical oncologists, 1.07-1.57 for the neuroradiologists, 1.07-1.08 for the neurosurgeons and 1.14-6.5 for the radiation oncologists. The intersecting volumes (on which all physicians agree) represented only 32 % and 34 % of the mean volume for the two patients. Compared to radia- tion and medical oncologists, neurosurgeons and neuroradiologists tend to delineate slightly smaller volumes; the results for the radiation group need to be taken cautiously because of the large delineation of one of the two observers. Lowest COVs, indicator of a smallest interobserv- er variation, are found for the group of neurosurgeons and neuroradiologists. Conclusions: The first step of 3D treatment planning, the delineation of base of skull meningiomas tumour, neces- sitates a good cooperation with a multidisciplinary team by using different imaging modalities as NMR and methionine PET. Difference between radiation oncologists and other specialities could be unconscious integration of geometrical uncertainties relevant in radiotherapy as the set-up variation, organ motion…
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Stereotactic radiation therapy for optic meningioma; an experience of Ramathibodi Hospital P2-7 Chomporn, Sitathanee (1); Mantana, Dhanachai (1); Putipan, Puataweepong (1); Lojana, Tuntiyatorn (1); Anuchit, Poonyathalang (2); Veerasak, Theerapanchareon (3) (1) Ramathibodi Hospital Mahidol University - Department of Radiology; (2) Ramathibodi Hospital Mahidol University - Ophthalmology; (3) Ramathibodi Hospital Mahidol University - Neurosurgery Department Bangkok, Thailand Background and objective: To report on technique and results of 12 patients with optic menin- gioma treated with stereotactic radiotherapy or stereotic radiosurgery at Ramathibodi Hospital. Patients and methods: Between November 1998 and January 2005, 12 patients (10 females, 2 males; age 25-67) with optic meningioma were treated with stereotactic radiation therapy. Five patients had no vision before starting radiation, 6 had impaired vision with or without proptosis or decreased facial sensation, and 1 had proptosis and lateral rectus palsy. All except one were treated with fractionated stereotactic radiotherapy (SRT) with an average dose of 51.6 to 59 Gy (mean 55.7), 1.8 Gy/fraction, prescribed at 90% isodose, delivered in 5-6 weeks. Stereotic radio- surgery (SRS) was used in one patient who had no vision. The dose of SRS was 15 Gy prescribed at 80% isodose. Results: After a median follow-up of 30 months (range 3-66), no tumor progres- sion was observed. There was no visual improvement in all 5 patients who were blind before radiation. Vision remained stable in 2, and improved in 4 patients. Vision became worse in one patient who had uncontrolled DM and hypertension. This patient developed vitreous hemorrhage 2 years after radiation and underwent surgery. Proptosis was stable or improved as well as facial sensation. One patient had decreased vision 4 months after radiation completion but fully recov- ered after steroid treatment. No complication was observed in other patients. Conclusion: Stereotactic radiation therapy is an effective treatment option for patients with optic meningioma. It results in good tumor control and improved or stable vision in the majority of patients who still have useful vision before treatment without serious complication.
Long-term follow-up of sellar and para-sellar meningiomas treated with stereotactic radiosurgery and fractionated stereotactic radiotherapy using the UCLA grading system P2-8 Carlos, Mattozo (1); Leonardo, Frighetto (2); Alessandra, Gorgulho (3); Cynthia, Cabatan-Awang (3); Timothy D., Solberg (4); Michael, Selch (5); Antonio, DeSalles (6) (1) UCLA Medical Center - Neurosurgery; (2) University of California Los Angeles - Neurosurgery; (3) UCLA Medical Center - Department of Neurosurgery; (4) UCLA Medical Center - Department of Radiation Oncology; (5) UCLA - Radiation Oncology; (6) UCLA Medical Center - Neurosurgery Los Angeles, USA Objectives: To evaluate the long-term follow-up of sellar and para-sellar meningiomas treated with Stereotactic Radiosurgery (SRS) and Fractionated Stereotactic Radiotherapy (SRT) according to the UCLA grading system. Materials and Methods: Treatment outcomes of 35 patients submit- ted to SRS and SRT at UCLA for sellar and parasellar meningiomas were retrospectively analyzed according to the UCLA grading system. Grade I meningiomas were limited to the cavernous sinus (Total: 4, SRS: 4), Grade II extended to the clivus or petrous bone (Total: 3, SRS: 3), grade III had compression of the optic structures (Total: 17 SRS: 7, SRT: 10), grade IV compressed the brain- stem (Total: 9, SRS: 7, SRT: 2)and Grade V had bilateral extension to the cavernous sinuses (Total: 247 Poster Abstracts
2, SRT: 2). There were 9 males (25.7%) and 26 females (74.3%) with a median age of 52 years (31-78). The median follow-up was 92.5 (57-141) for SRS and 60.5 (48-89) for SRT. Median doses were 1600 cGy (1200-2000) for SRS prescribed to the 50% (50-90) isodose line and 4680 cGy (2380-5040), prescribed to the 90% (50-95) for SRT. Results: Tumor control was 100% (14/14) for SRT patients and 85.7% (18/21) for SRS (p=.329, Pearson Chi-Square), for a total control of 91.4%. Two patients submitted to SRS presented with decrease in vision (9.5%). All other side-effects were minor and included 6 cases (28.5%) treated with SRS (assymptomatic brain edema in one, facial hypoesthesia in 3 and stroke related to carotid stenosis in other two). Only one patient submitted to SRT presented with asymptomatic brain edema (7.1%). Side-effects occurred in 6 high grade tumors (66.6%), comparing to three low-grade tumors (I and II). There were more side-effects in high grade tumors treated with SRS (p= 0.056, Fischer exact test). Conclusion: The current results suggest a trend towards increase in safety when SRT is used in high grade sellar and parasellar meningiomas.
Decision tree software: stereotactic radiation X conventional surgery P2-9 Alessandra, Gorgulho (1); Antonio, De Salles (1); Martin, Pellinat (2) (1) UCLA Medical Center - Department of Neurosurgery; (2) Idego Methodologies - VisionTree Healthcare Los Angeles, USA Introduction: Currently, multiple treatment options and physician bias to the most familiar approaches require a tool to help patients organize information and take appropriate decision. Materials and Methods: Seventeen patients facing the dilemma stereotactic radiation(SR) vs con- ventional surgery(CS) used VisionTree Healthcare software. SR and CS had been recommended when they used the decision-making software. Diagnosis was: cranial nerve neuroma(6), supra- tentorial tumor(4), pituitary adenoma(2), trigeminal neuralgia(2), chordoma/glomus jugularis/spinal tumor(1 each). Mean age was 58.68±12.73 (39-77) years, 12 male. Effectiveness/complications/recovery time/number of visits/specific relevant issues were rated by a physician, using literature data and personalized risks factors. Priorities were graded from 1- 10(10=best). Personal values (like death/sequelae/fear) were included. Evaluation survey was completed by 1-5 scale (5=best). Software calculates a normalized score (0-100%) reflecting patient’s priorities, likelihood/willingness ratings (scale:0–10) for options. This score represents to what degree (in percentage) the option met the patient’s rated criteria. Results: Scores in order of preference were obtained. For the analysis between stereotactic radiation and open surgery, only the first and last scores were compared. Intermediate scores concerning other minimally invasive options (SRSxSRT, SRSXradiofrequency) were not considered. The mean score for first option was 87±9 versus 43.4±18.43 for last option. Survey mean rates were: 4.7±0.6 for friendliness nav- igation, 4.5±0.8 for recommendation to others, 4.41±0.9 for satisfaction. Treatment option rankings were the expected in all but one patient who was unable to make a decision. All but this patient took the first treatment option. All first options had a score above 70. Conclusions: Decision-making software use is an innovative concept to help patients maximize expectations/priorities. Patients expressed satisfaction. VisionTree was particularly helpful evalu- ating therapeutic options in a clear/organized fashion. All available options are presented and patients are able to objectively review, evaluate and confirm their option. Data is stored electron- ically as record of the patient’s informed consent. 248 Poster Abstracts
Quality of life after interdisciplinary treatment of cavernous sinus meningiomas P2-10 Markus, Gross (1); Ahmed, Farhoud (2); Martin, Henzel (1); Stefan, Heinze (2); Ulrich, Sure (2); Helmut, Bertalanffy (2); Rita, Engenhart-Cabillic (3) (1) Philipps University Marburg - Department of Radiotherapy; (2) Philipps University Marburg - Department of Neurosurgery; (3) Philipps University Marburg - Radiotherapy and Radiooncology Department Marburg, Germany Background: Despite advances in microsurgical techniques, meningiomas involving the cav- ernous sinus often require multidisciplinary treatment including stereotactic radiotherapy either as a primary treatment, or to control residual or recurrent tumors after previous surgery. Goal of this study was to evaluate quality of life (QOL) after different interdisciplinary tumor treatment. Methods: 104 patients (20 men, 84 women) harboring cavernous sinus meningiomas were ret- rospectively analyzed to evaluate post-treatment QOL, as well as morbidity and outcome. QOL was assessed by Short Form 36 (SF36), measuring 8 different health domains. Follow-up was achieved in 96 patients. In operated patients it was 44 months, in patients treated by radiother- apy alone 24 months. The study group was divided into 3 therapeutic categories: patients treat- ed surgically only (group I, 22 patients), patients treated with stereotactic fractionated radiother- apy (group II, 34 patients), and patients who were treated with both modalities, surgery and radiotherapy (group III, 40 patients). Results: 75% of tumors in group I could be excised totally. There was no mortality in this series. Post-operative cranial nerve impairment occurred in 47% of surgical patients, 12% remained permanent, one patient suffered from angular gyrus infarction. After irradiation acute toxicity was seen rarely (3%). Clinically significant late morbidity and new neurological palsies were not encountered. No tumor progression or regrowth was observed in group I and III, in group II one tumor progress occured. No statistically significant difference in QOL was found between the 3 groups and compared with values of normal USA population. However, patients in group II had the best QOL in all but one health domains. Conclusion: Gross total excision provides a long-term recurrence free survival with acceptable morbidity. Quality of life (QOL) after stereotactic radiotherapy is excellent, as well, therefore offering an important alter- native treatment option.
Stereotactic radiosurgery for atypical and anaplastic meningiomas P2-11 Hideyuki, Kano (1); JUn, Takahashi (2); Norio, Araki (3); Masumi, Hiraoka (3); Naohiro, Horii (4); Kasumi, Araki (1); Tetsuya, Ueba (1); Kosuke, Yamashita (1); Nobuo, Hashimoto (2) (1) Kishiwada City Hospital - Neurosurgery; (2) Kyoto University Graduate School of Medicine - Neurosurgery; (3) Kyoto University Graduate School of Medicine - Radiation Oncology Department; (4) Kishiwada City Hospital - Radiation Oncology Kishiwada, Osaka Introduction: Atypical and anaplastic meningiomas frequently recur in the relatively short-term after surgery, even if they are radically resected. We have followed such postoperative cases by short-interval repeated MRI and have performed stereotactic radiosurgery (SRS) toward progres- sive tumors as a salvage therapy. The objective of this report was assessment of the degree of tumor control, the risk of complications, and the presence of variables that predict outcome in patients treated with SRS for high-grade meningiomas. Methods: We reviewed 12 high-grade 249 Poster Abstracts
meningioma patients with 30 lesions treated by Linac-based SRS at Kyoto University Hospital between 1997 and 2002, all of which underwent initial surgery and received SRS for tumor pro- gression. They included 10 atypical meningiomas and 2 anaplastic ones according to the WHO classification. A mean tumor volume was 6.35cc and a mean marginal dose of SRS was 18.0Gy (12-20Gy). Results: After a mean follow-up period of 37.3 months (6-84 months), 13 lesions had tumor progression within the SRS field and 6 lesions had out of the SRS field. Nine of 16 lesions, which were treated by SRS with marginal dose of less than 20Gy, had local recurrence in the radi- ation field with the median time to progression (TTP) of 6 months. In contrast, the mean TTP was 21 months in 14 lesions treated with marginal dose of 20Gy. The marginal dose less than 20Gy was a statistically significant factor for a short-term progression in high-grade meningiomas (P<0.0139). Five-year progression-free survival ratio in lesions treated with SRS below 20Gy and 20Gy were 29.4% and 63.1%, respectively. Conclusion: High-grade meningiomas were recom- mended to receive SRS with marginal dose of more than 20Gy. And MRI follow-up in the close interval will be effective on growth inhibition of high grade meningiomas because SRS can be achieved toward small-sized targets.
Long-term experience of gamma knife radiosurgery for benign skull base meningiomas P2-12 Wolfgang, Kreil (1); Verena, Weigl (1); Sandro, Eustacchio (1); Josef, Luggin (1); Georg, Papaefthymiou (1) (1) Medical University Graz - Dept. of Neurosurgery Graz, Austria Objectives. As most of the Gamma knife reports are related only to short- or mid-term results we have evaluated the effectiveness and toxicity of radiosurgical treatment for benign skull base meningiomas in 200 patients with a follow-up of 5 to 12 years in order to define the role of GKRS for basal meningiomas and to provide further data for comparison with other treatment options. Methods. Ninety-nine patients were treated with a combination of microsurgical resection and GKRS. In 101 patients GKRS was performed as the sole treatment option. Tumour volumes ranged from 0.38 ccm - 89.8 ccm (median 6.5 ccm) and doses of 7 Gy to 25 Gy (median 12 Gy) were given to the tumour borders at covering isodose volume curves (range: 20 % - 80 %, median 45 %). Results. The actuarial progression-free survival rate was 98.5 % at 5 years and 97.2 % at 10 years. Passing radiation-induced oedema occurred in two patients (1 %). The neurological status improved in 83 cases (41.5 %), remained unaltered in 108 patients (54 %) and deteriorated in 9 cases (4.5 %). Worsening was transient in 7 patients (3.5 %) and unrelated to tumour or treat- ment in one single patient (0.5 %). Repeated microsurgical resection was performed in five patients following GKRS (2.5 %). Conclusions. GKRS has proved to be an effective alternative to microsurgical resection, radiotherapy and Linac-based radiosurgery for adjunctive and primary treatment of selected patients with basal meningiomas. Due to the excellent long-term tumour control rate and low morbidity associated with GKRS this treatment option should be used more frequently in the therapeutic management of benign skull base meningiomas.
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Gamma knife radiosurgery for the treatment of skull base meningiomas P2-13 Selcuk, Peker (1); Turker, Kilic (1); Meric, Sengoz (2); Necmettin, Pamir (1) (1) Marmara University School of Medicine - Department of Neurosurgery; (2) Marmara University - Radiation Oncology Istanbul, Turkey The aim of this retrospective study is to show the efficacy of the gamma knife radiosurgery for skull base meningiomas. We reviewed the records of 190 meningioma patients treated with gamma knife radiosurgery between 1997 and 2001. Skull base meningiomas were 64% (122 cases) of all meningioma patients. Cavernous sinus were (60 cases) the prominent localisation and the remaining skull base meningioma areas were mostly petrous apex, petroclival region, sphenoid wing and tentorium. Patient age ranged from 18 to 80 years and the follow-up period for patients ranged 4 to 8 years. We used median 9 isodose area and median dose at the tumor 50% isodose line was 14 Gy (ranged between 12 to 20 Gy). The tumor growth control was achieved in 110 cases (90%) and only 12 cases' tumors carried on growing. Subclinical, neuro- radiologically seen neural tissue changes revealing after medical therapy were seen in 6 patients. Gamma knife radiosurgery is an effective and safe treatment modality for skull base located meningiomas especially the ones invading cranial nerves and vascular structures.
Stereotactic LINAC-radiosurgery for meningiomas P2-14 Salvador, Somaza (1) (1) La Floresta Medical Institute - Stereotactic Radiosurgery Unit Miami, USA Object: To present the experience treating 63 patients with meningiomas using stereotactic Linac- Radiosurgery Material and methods: We presented our experience in the management of 63 patients with meningiomas which were treated using stereotactic Linac-radiosurgery technique. During the first 60 months of operation of the first radiosurgical unit in Venezuela since February 2000, 430 patients with vascular malformations, tumors and trigeminal neuralgia were treated. Of these, 63 patients ( 48 women and 15 men, age 21 to 86 years) had meningiomas. The mean follow-up period was 38 months (range 4 to 54 months). The tumor volume was 8.49 cc (range 1.14 – 47.71 cm3). The mean prescription dose was 14.5 Gy (range 12 – 18.75 Gy). The mean peripheral isodose was 80%. Results Tumor control was obtained in 58/59 patients. Fifty nine patients were evaluated with serial post-operative MR images performed at 6, 12, 18, 24, 36, 48 months, etc., by protocol after radiosurgery. Eighteen tumors showed a loss of central contrast enhancement on MR images. We saw no change in the size of 35 tumors; twenty one tumors decreased in size. Patients were clinically stable without evidence of any new neurological deficits and 27 patients improved. One patient died in the course of follow-up due to another condition not related to his treated meningioma. No immediate post-operative complications or periopera- tive seizures occurred. Temporary new neurologic deficits developed in 2 patients at 14 and 18 months. They presented transient trigeminal hypoesthesia. Conclusion: Stereotactic Linac- Radiosurgery in our experience has proved to be a safe and effective therapy for patients with subtotal resected or recurrent meningiomas. Linac-Radiosurgery is also an effective primary alter- native treatment for patients with advanced age, deteriorated medical conditions or high-risk tumor location that preclude a microsurgical approach 251 Poster Abstracts
LINAC radiosurgery in the management of parasagittal meningiomas P2-15 Roberto, Spiegelmann (1); Jacob, Zauberman (2); Janna, Menhel (3); Rafael, Pfeffer (3); Dror, Alezra (3) (1) Sheba Medical Center - Department of Neurosurgery; (2) Sheba Medical Center - Neurosurgery; (3) Sheba Medical Center - Department of Oncology Ramat Gan, Israel Parasagittal meningiomas have a relatively high incidence of recurrence after conventional sur- gery due to their attachment to the sagittal sinus. Patients frequently require repeat operations throughout their life. Radiation treatment has been effective in the past to control meningiomas. Radiosurgery is an appealing alternative to avoid radiation exposure of normal brain. At our cen- ter, 49 parasagittal meningiomas were managed by radiosurgery during a 10-year period (1993- 2003). They represented 18% of our meningioma series. Thirty eight patients had one or sever- al previous microsurgical resections. The mean dose to the tumor margins was 1400 cGy. Two patients with malignant tumors died early after treatment. Eight patients were lost to follow-up. The remaining 39 patients were available for analysis after a mean follow-up of 39 months (12- 132). 22 tumors were smaller, 10 were stable, and 5 had grown. Three of the latter required repeat surgery. Of 6 patients with histologically-proven aggressive tumors (atypical/malignant) only 1 was controlled at 2-year follow-up. The actuarial tumor control rate for the series is 87%. MRI changes compatible with radiation injury were observed in 6 patients (15%); five were symp- tomatic. Only 2 patients remained with persistent deficits. Conclusion: LINAC radiosurgery was highly effective in the control of benign parasagittal meningiomas in this series. Failures were observed outside of the treatment margins. Better definition of intrasinusal components will like- ly improve tumor control.
Optic nerve sheath meningioma : Comparison of 3D-conformal radiotherapy (3D-CRT), stereotactic radiotherapy (SRT), and intensity modulated radiotherapy (IMRT) P2-16 Pornpan, Yongvithisatid (1); Porntip, Thamwinitchai (2); Paitoon, Tawsagul (1); Mantana, Dhanachai (1); Sawwanee, Asavaphatiboon (3); Chumpoj, Kakanaporn (2); Wichan, Prasertsilpakul (1); Chirapha, Tannanonta (1); Jiraporn, Laothamatas (1); Prasert, Assavaprathuangkul (1); Kanjana, Boonpitak (1) (1) Ramathibodi Hospital Mahidol University - Department of Radiology; (2) Siriraj Hospital - Radiology; (3) Ramathibodi Hospital Mahidol University - Radiology Bangkok, Thailand Purpose: To assess the efficacy of different radiotherapy planning techniques (3D-CRT, SRT, and IMRT) in patients with optic nerve sheath meningioma Methods: Twelve cases with optic nerve sheath meningioma who were treated with SRT technique during 1995-2004 were replanned using the 3D-CRT and IMRT planning system. Contrast-enhanced computed tomography(CT) data with 1.5-mm slice thickness was used. Plans from the three techniques were compared with respect to dose conformity, dose uniformity, dose volume histogram(DVH), dose to organs at risk(OAR), and dose distribution. The prescribed dose was 50 Gy in 25 fractions. Results: IMRT plan was superior to 3D-CRT and SRT in terms of target dose conformity and uniformity. There was no major difference of the target coverage among the three techniques. Regarding the spar- ing of OARs, IMRT was not different from SRT and both were better than 3D-CRT. Conclusion: IMRT and SRT gave lesser dose to the surrounding normal organs compared with 3D-CRT in 252 Poster Abstracts
patients with optic nerve sheath meningioma. Further studies are needed to establish the true clinical advantage of each technique.
Does diffuse white matter change often seen after WBRT also occur after GK for multiple brain METs? P2-18 Masaaki, Yamamoto (1) (1) Katsuta Hospital - Mita Gamma House Hitaxhi-Naka, Japan Does diffuse white matter change often seen after WBRT also occur after GK for multiple brain METs? Masaaki Yamamoto , Bierta Barfod, Yoichi Urakawa Katsuta Hospital Mito GammaHouse We assessed whether diffuse white matter change (DWMC), often seen after WBRT and consid- ered to represent a possible risk for future dementia, occurs after GK treatment for patients with multiple brain METs. Among the more than 1200 patients who have undergone GK radiosurgery for brain METs in our facility since 1998, we selected 60 (the original tumor was lung cancer in 40) with 5 or more lesions for this study. Follow-up MR images were obtained more than 6 months after treatment in these 60 patients. The mean and maximum tumor numbers were 13 and 48, respectively. There were 40 females and 20 males. Mean age at the time of radiosurgery was 60 years, range 35 to 82. MR images obtained 7-56 (mean; 14) months after treatment demonstrated no DWMC in any of the 60 patients. For comparison with WBRT for brain METs, we also analyzed 45 (the original tumor was lung cancer in 29) patients referred to us who had undergone WBRT during the same period. There were 22 females and 23 males. Mean age at the time of radiosurgery was 58 years, range 19 to 83. MR images obtained 6-42 (mean; 16) months after WBRT demonstrated DWMC in 21 (47%) of these 45 patients. DWMC occurred in 8%, 50%, 63% and 84% of the patients, respectively, 6, 12, 18 and 24 months after WBRT. The incidence of DWMC was higher in elderly (_„60 years, 50%) than in younger patients (33%), though the difference did not reach statistical significance. Although DWMC incidence correlated significantly with irradiation doses in younger patients (p_ƒ.0001), this was not the case in the elderly group (p__.5541). In conclusion, it is reasonable to assume that GK radiosurgery for mul- tiple METs would not have an adverse effect on mental function in long-term survivors.
Stereotactic irradiation for choroidal melanoma in the elderly P2-19 Stéphanie, Bolle (1); Isabelle, Rutten (1); Jean-Marie, Deneufbourg (1) (1) CHU Liège - Radiothérapie Liège, Belgium Aim: To evaluate the role of stereotactic radiotherapy (SRT) in the management of choroidal melanoma in the elderly. Methods: A retrospective study of 4 patients with choroidal melanoma ineligible for enucleation or brachytherapy for reason of large tumor size, poor general status, med- ical contraindication to anaesthesia or important visual deficit treated with SRT during 1996 and 1997. Median age was 79 years. Three patients presented medium-size choroidal melanoma and the last one large-size. The prescribed dose was one to three fractions of 10-12,5 Gy (one frac- tion/week). Median follow-up was 43 months. Results: No acute side effect was observed except slight conjunctival irritation related to eye fixation by the ophtalmologist. Three patients had par- tial tumor response and one a complete response. No enucleation was required for recurrence or 253 Poster Abstracts
complication. No radiation induced late effect was detected. At last ophtalmological follow-up, lack of pain and absence of tumor progression was observed; visual acuity was reduced of 2 lines. Side effects of radiation and their impact on visual function were difficult to estimate regarding other pre-existing ophtalmologic diseases (macular degeneration, cataract, glaucoma, retinal detachment). Three deaths occured respectively at 7, 50 ant 79 months and were not tumor relat- ed. Conclusions: SRT for choroidal melanoma in the elderly is feasible, well tolerated and tumor control can be obtained by such a method. However, the available data are not sufficient to eval- uate long term side effects and future clinical studies are necessary to optimise dose and fraction- ation. Currently, we believe that SRT can at least be proposed as palliative treatment for the elder- ly who are unsuitable for enucleation or conservative treatment owing to medical reasons.
Conformal stereotactic radiotherapy in the management of the orbital hemangioma P2-20 F, Mascarenhas (1); M, Santos (1); I, Monteiro Grillo (1); A, Almeida (2) (1) Hospital de Santa Maria- Lisboa-Portugal - Radiotherapy Dpt; (2) Hospital de Santa Maria- Lisboa-Portugal - Radiology Dpt Lisboa, Portugal Background: Surgical resection and corticosteroid therapy have been the most commonly used methods of treatment in the management of orbital hemangioma. Conventional external radio- therapy has been traditionally deferred face to those modalities by the high incidence of late ocu- lar complications. The modern techniques of conformal stereotactic radiotherapy (CSR) can achieve high local control rate and substantial clinical improvement with a minimal radio-induced morbidity. Material and Methods: A case of recurrent orbital hemangioma previously submitted to surgery and corticoesteroid therapy is described. The clinical presentation, diagnostic charac- terization and treatment protocol are reviewed. Comparative evaluation previous and 2 years after treatment are presented. The patient was treated with 6 Mv photons CSR receiving a total dosis of 20 Gy in 10 fractions. Results: This recurrent lesion causing marked symptoms as right orbital pain, diplopia and proptosis had a complete clinical improvement 3 to 4 weeks after treat- ment. The follow-up 30 months after CSR has revealed a significant and persistent reduction of the lesion with no moderate or severe radiation-induced secondary effects. Conclusions: This case is illustrative from the efficacy of CSR and supports this modality as an alternative treatment in the unresectable orbital hemangioma preserving the organ and its function and providing the local tumor control and a better quality of life with minimal morbidity.
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Accuracy in ophthalmic radiosurgery - eye fixation, imaging, dosimetry P2-21 Josef, Novotny Jr. (1); Josef, Novotny (2); Roman, Liscak (3); Vaclav, Spevacek (4); Jan, Hrbacek (5); Pavel, Dvorak (6); Tomas, Cechak (7); Josef, Vymazal (8) (1) Na Homolce Hospital - Medical physics; (2) Na Homolce Hospital - Medical physics; (3) Na Homolce Hospital - Stereotactic and radiation neurosurgery; (4) CTU in Prague, Faculty of Nuclear Science and Physical Engineering - Dosimetry and application of ionizing radiation; (5) CTU in Prague, Faculty of Nuclear Science and Physical Engineering - Dosimetry and application of ionizing radiation; (6) CTU in Prague, Faculty of Nuclear Science and Physical Engineering - Dosimetry and application of ionizing radiation; (7) CTU in Prague, Faculty of Nuclear Science and Physical Engineering - Dosimetry and application of ionizing radiation; (8) Na Homolce Hospital - Stereotactic and radiation neurosurgery Prague, Czech Republic Following issues concerning the accuracy of the ophthalmic radiosurgery were addressed: stabil- ity and reliability of eye fixation, accuracy of stereotactic imaging, absolute and relative dosime- try. Stability and reliability of eye fixation was checked by two subsequent magnetic resonance imaging (MRI) performed in at least two hours interval. Accuracy of stereotactic imaging was assessed by a special phantom for image distortion evaluation. Since patient is usually treated in prone position comparison between MRI done in prone and supine patient position was done as well. Special water filled head phantom was used for measurements to assess accuracy of absolute and relative dosimetry in eye lesion. Altogether six different treatments were simulated and evaluated. Polymer-gel dosimeter evaluated by nuclear magnetic resonance was used to assess the accuracy of relative dosimetry. Small ion chamber was used to assess the accuracy of absolute dosimetry. Clinically important inaccuracies were observed neither in eye fixation nor in MRI of the eye. Typical image distortion for selected MRI sequence was not higher than 1.0 mm (mean value 0.5 mm). Deviations observed between two subsequent MRIs done in at least two hours interval as well as for MRIs done in prone and supine patient position were typically with- in 0.5 mm. A comparison of calculated dose profiles from the treatment planning system and those measured by the polymer-gel dosimeter in all three axes demonstrated a very good agree- ment. Typical deviations between measured and calculated absolute dose were within 5 % for depths larger than 10 mm. For depths smaller than 10 mm there was observed up to 15-20% deviation compare to the treatment planning system calculations.
Combined positron emission tomography and magnetic resonance imaging in the dosimetry planning of radiosurgery using Leksell gamma knife for intracranial tumors in children. Preliminary experience P2-23 Benoit, Pirotte (1); Serge, Goldman (2); Philippe, David (3); Daniel, Devriendt (4); Jacques, Brotchi (1); Patrick, Van Bogaert (5); Marc, Levivier (6) (1) Hôpital Erasme - Neurochirurgie; (2) Hôpital Erasme - PET Scan; (3) Hôpital Erasme - Neuroradiologie; (4) Institut J. Bordet - Radiothérapie; (5) Hôpital Erasme - Paediatric Neurology; (6) Hôpital Erasme - Centre Gamme Knife Brussels, Belgium Objective. To evaluate the integration of Positron Emission Tomography (PET) images into the radiosurgical treatment planning of intracranial tumors in children. Methods. Between 2000 and 2005, PET images using [18F]fluorodeoxyglucose (FDG) and [11C]methionine (Met) were com- 255 Poster Abstracts
bined to magnetic resonance (MR) images in the dosimetry planning of radiosurgery of intracra- nial tumors in 8 children at Erasme Hospital, Brussels, Belgium. All radiosurgical procedures used the Leksell gamma knife° (LGK) model C. These 8 children (5 males/3 females; aged from 2 to 12 years) presented tumor residue that were judged inaccessible for surgical excision (2 ependymo- mas, 2 pilocytic astrocytomas, 3 glioblastomas and one choroid plexus carcinoma). The frame fix- ation, the images acquisition and the radiosurgical procedures were performed the same day under general anesthesia and under the attendance of a senior anaesthesiologist in all cases. Both PET and MR images were then acquired in frame-based stereotactic conditions according to a methodology previously described for PET-guided neurosurgical procedures. FDG-PET was used in one case, Met-PET in 6 and PET with both tracers in one). Level and distribution of PET tracer uptake in the tumor were analyzed to define tumor contours allowing to build a PET volume. PET volume was subsequently projected on MR images and compared to MR data (MR volume) in order to define a final target volume for the dosimetry planning of radiosurgical treatment. Maximal tumor volume was irradiated in each case, with the intention to treat the entire abnor- mal metabolic area comprised in the radiosurgical planning. Pre- and post-operative analysis of MR and PET images evaluated whether integrating PET data in the radiosurgical planning con- tributed to improve the tumor volume definition and the radiosurgical treatment. Conclusions. Independent and complementary metabolic data on tumor heterogeneity or extent were useful for planning the radiosurgical treatment. In all procedures, PET data helped to assess tumor extent and contributed to define a final target volume different from that obtained with MR alone. These preliminary results are promising and suggest that PET-guidance could help to optimize the tumor volume definition and to target radiosurgical treatment to tumor portions which present the highest evolving potential.
Integration of CT-PET and MRI images in stereotactic procedures using hardware coregistration P2-24 Piero, Picozzi (1); Luca, Attuati (2); Alberto, Franzin (2); Lorenzo, Gioia (2); Claudio, Landoni (3); V.V, Dolenc (4) (1) Ospedale San Raffaele - Stereotactic Neurosurgery & Gamma Knife Department; (2) Ospedale San Raffaele - Neurosurgery Department; (3) Ospedale San Raffaele - Dept. of Nuclear Medicine; (4) University of Ljubljana, Clinical Center - Department of Neurosurgery Milano, Italy INTRODUCTION: Metabolic information could be an useful instrument to further improve the accuracy of stereotactic procedures, nevertheless integration of PET data in stereotaxy is cumber- some, as the current version of GammaPlan does not accept them. We developed a method that needs only the CT indicator box to co-register PET images within CT study and integrates this information with MRI imaging. MATERIALS AND METHODS: The study was performed using a PET/CT scanner. A standard CT bed adapter was attached to the scanner couch, on which the patient, with the stereotactic frame fixed, was positioned. Images can be acquired using any radioisotope. CT and PET images were exported in DICOM 3 standard and then reconstructed from spiral acquisition data (FOV 35 mm): • CT: 512x512 matrix (pixel size 0.9766 mm, 5 mm slice thickness, 4.25 mm gap). • PET: 128x128 matrix (1.9531 mm, 4.25 slice thickness, Hann and Ramp filters). A homemade software, based on MatLab, was created to fuse PET and CT studies. From PET images, pixels showing an intensity value less than 30% of the maximum were threshold to zero to exclude “background” noise. In a new study, PET remaining pixels, belong- 256 Poster Abstracts
ing to the brain, were overwritten to the correspondent ones in CT images. So, CT head struc- tures were replaced with the corresponding PET ones, maintaining the stereotactic markers. Accuracy of hardware co-registration was checked to be ~ 1 mm by a quality control: maximal value of misalignment was 0.8 mm (20 cm from FOV centre). The new study was then transferred to our Gamma Plan analysis workstation. RESULTS: Using CT indicator box simplifies the proce- dure and needs no operator interaction during matching. No radioactive spilling is necessary. This method was tested on a phantom and on patients. Localization accuracy of the PET images is lim- ited by the slice thickness.
Role of positron emission tomography in stereotactic radiosurgery with gamma knife P2-25 Yoshimasa, Mori (1); Tatsuya, Kobayashi (1); Naoki, Hayashi (1); Yuta, Shibamoto (2); Jun, Yoshida (3) (1) Nagoya Kyoritsu Hospital - Gamma Knife Center; (2) Nagoya City University - Department of Radiology and Radiation Oncology; (3) Nagoya University School of Medicine - Department of Neurosurgery Nagoya, Japan We usually use magnetic resonance imaging (MRI) and/or computed tomography (CT) for dose planning of stereotactic radiosurgery because MRI and CT precisely show us anatomical structures including brain lesions. On the other hand, positron emission tomography (PET) and single pho- ton emission CT (SPECT) give us valuable functional information, though spatial resolution of these images is not good. FDG (18F-fluolo-2-deoxy-D-glucose)-PET is useful to evaluate tumor extension in skull base tumors. In a patient with renal cell carcinoma FDG-PET showed a petrous bone metastasis as a remarkable uptake area in the cold surrounding structures. During follow- up after radiosurgery we sometimes have difficulties in differentiating tumor recurrence from radi- ation necrosis, because both types of lesions look alike on MRI as regrowing irregular-shaped well-enhanced areas. PET images provide additional metabolic information in such cases. We treat the regrowing lesions again by repeat radiosurgery in three cases of brain metastases because high uptake of FDG implied viable recurrent tumors. After repeat radiosurgery they were shrunk successfully. In glioma cases PET provides complementary information that contribute to the optimization of the treatment of tumors. Metabolic and functional information of PET can be used for diagnosis, guidance of therapies, and treatment monitoring in stereotactic radiosurgery with gamma knife.
Tomotherapeutic intensity-modulated radiosurgery (IMRS): improving dose gradients and maximum dose after inverse optimization using ActiveRx P2-26 Martin, Fuss (1); Bill J., Salter (2) (1) UTHSC San Antonio - Radiation Oncology; (2) Cancer Therapy & Research Center - Medical Physics San Antonio, USA Intensity-modulated radiosurgery (IMRS) for brain metastases and AVM using the Nomos Peacock system has been delivered in >150 cases in our institution over the last 4 years. A new software tool provided within the Corvus planning software (ActiveRX)allows for post inverse planning re- optimization and individualization of the dose distribution. We analyzed this tool with respect to increasing the steepness of the dose gradient and dose inhomogeneity while maintaining dose conformity. Fifteen radiosurgery plans for solitary brain metastases that were clinically delivered 257 Poster Abstracts
during the last two months were analyzed. All plans were copied and ActiveRX, a tool available during plan review, was opened. The toolset in ActiveRX includes an eraser, a pencil to redefine isodose lines and a drag and drop tool, allowing reshaping of isodose lines. To assess changes in the steepness of the dose gradient and dose homogeneity, the 100%, 90%, 50% and 25% iso- dose volume, the volume of the target, maximum dose and mean dose to the target were sam- pled. Target volumes ranged from 0.6 to 14.1 cm3 (mean/median 3.9/1.8 cm3). Mean RTOG con- formity index (CI) of plans delivered was 1.23±0.31, and mean homogeneity index (HI) was 115±5%. Using ActiveRX, the mean CI was slightly improved to 1.14±0.1, with associated increase in HI to 141±10%. The respective average Ian Paddick CI for the 100%, 90% 50% and 25% isodose lines were 0.79 vs.0.83, 0.44 vs. 0.59, 0.12 vs. 0.19, and 0.04 vs. 0.07 (all p<0.05), with significant improvements using ActiveRx post-optimization. A post inverse plan- ning optimization tool for IMRS plans allowed for statistically significant improvements in the steepness of the dose gradient, and increased maximum and mean target doses compared to clinically delivered plans that were already considered excellent. Gains were especially pro- nounced in the reduction of normal brain tissue included into the 90%, and 50% isodose lines. We have since made this process part of the clinical routine for all cranial IMRS procedures.
Radiosurgery, staged radiosurgery and fractionated radiosurgery: experiences of gamma knife and CyberKnife P2-27 Hiroshi K., Inoue (1) (1) Institute of Neural Organization - Restorative Neurosurgery Fujioka, Japan The technical development of radiosurgery expanded treatment indications for cranial and extracranial lesions. Benefits of gamma knife and CyberKnife are reported based on own experi- ences. Gamma knife provides 201 focused beams at a point. High dose treatment to small lesions is sharp and rapid. No hair loss appears even in the treatment of multiple metastases more than 10 lesions. Fractionation (3 times of low-dose radiosurgery) is also possible during 3 to 5 days of frame fixation (Stereotact Funct Neurosurg, 1995). Small lesions, multiple lesions and functional disorders are good indications for gamma knife. CyberKnife is based on frame-less stereotaxy and has large collimators to 60mm. 50 to 100 beams are usually used for a lesion by conformal dose planning. Staged or fractionated radiosurgery for large lesions is able to perform painlessly. Intensity modulated radiation therapy is also possible for malignant invasive tumors. Large lesions, invasive lesions and peripherally situated pathologies are good indications for CyberKnife. It is concluded that development of radiosurgery may provide further indications, improved results and minimal complications.
Today’s technology and application of a dedicated neuro-radiosurgery systems P2-28 Franz, Krispel (1) (1) American Radiosurgery, Inc. - Research and Development San Diego, USA Radiosurgery as a Neurosurgical procedure has established itself over the last 40 years. Even that the basic principle is still the same today, the advances in technology for diagnosis and therapy has driven this procedure to a very high precision. The increased knowledge in detailed Neuro 258 Poster Abstracts
anatomy and physiology allows now to fully utilize this precision to the benefit of the patient. The Gamma ray based rotating system “GammaART-6000™ “ employs newly patented technologies, taking full advantage of today’s precision diagnostic. Together with the advanced “4 D” comput- er planning system, this neuro-radiosurgical Instrument marks the latest innovation in this field. 30 needle beams rotate around the target in non overlapping circles. The sources are arranged in one hemispheric sector and can be turned off at any time during treatment. This new technique allows “a-symmetric” application of radiation, leading to better conformance and smaller targets. Very small lesions as well as un- symmetric larger targets can be treated with high precision. The first machine of this kind is now operational since 1 _ years in USA. The technology is protected by US patent US 6,512,813B1, US 5,528,653 and US 5,757,886. Clinical results are given elswhere at this conference. A descriptions of the system and its relation to small structure Neuroanatomy is given.
Dynamic patient positioning using Leksell gamma knife P2-29 Stefan G, Scheib (1); Stefano, Gianolini (2); Friederike, Reich (3) (1) Klinik im Park - Gamma Knife Center; (2) Klinik im Park - Department of Medical Radiation Physics; (3) Unitversity of Applied Science Remagen - Department of Medical Engineering and Sports-Medical Engineering Zürich, Switzerland In order to investigate the potential benefit of dynamic patient positioning within the radiation focus using the gamma knife, which is not possible with the current version of the APS, a proto- type of a triple axis scanner was build and used together with gamma knife B. The stereotactic frame is fixed to this scanning system, which is able to move the frame whilst the patient couch remains in the treatment position. Each of the three orthogonal linear axes can be operated inde- pendently. The system is connected to a PC where all parameters are visualised in real time. The positioning reproducibility is less than 1/10 mm and the range of the axes enable the whole stereotactic space to be covered. The scanning speed for each axis can be chosen up to 2.5 mm/s. The frame can be moved in 3D either by using constant velocities for each axis (drive mode), by varying velocities for each axis (dynamic mode), or by stepping a given increment along each axis (stepping mode). Dedicated dose distributions can be applied using appropriate dose optimisa- tion algorithms. This could comprise homogeneous dose distributions throughout the target, intended dose inhomogeneities in selected areas within the target, or selected dose gradients at peripheral target regions. Using the scanning device in the drive mode together with the 4 mm collimator allows the application of homogeneous dose distributions. In order to produce 3D opti- mised dose distributions a dose optimisation algorithm is implemented. The flexibility of the scan- ning system allows to explore the potential benefit of a scanning gamma knife. Calculated and measured dose distributions are compared to those using standard gamma knife technique.
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Extracranial stereotactic IMRT - A study of set-up reproducibility P2-30 Meg, Schneider (1); Robert, Smee (1); Lyn, Emanuel (2); John, Way (3); Karl, Chan (4) (1) Prince of Wales Hospital - Department of Radiation Oncology; (2) University of New South Wales - Prince of Wales Hospital - Department of Radiation Oncology; (3) Prince of Wales Hospital - Physics Department of Radiation Oncology Randwick, Australia INTRODUCTION: Three patients with vertebral body lesions were treated with a stereotactic IMRT technique. Accuracy and reproducibility in the set-up are paramount, as all three patients had received previous radiation, with the spinal cord being the organ at risk. METHODS: All patients were set-up using the Body Fix System (Radionics/Medical intelligence). This system comprises a full body vacuum bag attached to an indexed carbon fibre base-board, to which a stereotactic localiser is attached. It also allows the use of a double vacuum system, which is intended to achieve a high level of reproducibility and restriction of internal organ motion. Xknife RT 3 plan- ning software was used for planning, and a set of DRR’s (pa and lateral) was calculated for each patient. At treatment, a pa and lateral port film were taken second daily, which were then com- pared to the DRR’s that were produced by the planning system. Deviations in three dimensions were then measured (AP, LAT and Vertical) and evaluation was then recorded. These results will be presented. The time required to produce the initial mould was measured, as well as set-up and treatment times. RESULTS: The initial results are encouraging, but data is still being collect- ed. Results will be presented and discussed. CONCLUSION: The production of the vacuum bag was no longer than other immobilisation modalities used in radiotherapy. With experienced RT’s, it was actually quicker and simpler than production of a thermoplastic mask, which is a common- ly used technique in head and neck irradiation. Treatment set-up times compared favourably with other conformal radiotherapy techniques.
Implementation of A 6D robotic couch-top for the automation of image-guided brain SRS and spinal SRT P2-31 Almon, Shiu (1); Eric, Chang (2); Conjung, Wang (1) (1) The University of Texas M.D. Anderson Cancer Center - Radiation Physics; (2) The University of Texas M.D. Anderson Cancer Center - Radiation Oncology Houston, USA This study is focused on the implementation of a 6D Robotic couch-top for the image-guided brain SRS and spinal SRT. A robotic couch-top is replaced the existing couch-top on our LINAC/CT- on-rails unit. This couch-top consists of two platforms, are connected by six linear, length adjustable cylinders. The system is capable of moving the upper platform relative to the lower one in all three axes in space. The couch-top movements can be directed via the tracking and positioning software and the dead-man switch on the control panel. The software along with 3 infrared LED cameras system allows positioning the couch-top automatically. To automatically setup the patient accurately, first, the 3 cameras were calibrated to ensure the cameras covered 1 m2 area near isocenter. Setup the MIS to ensure the lasers aligned with the radiation isocenter. Then the calibration cube was used to define the daily isocenter. Finally, the localizers for body frame, CRW frame, and couch-top leveling device with sphere markers were created for the spine, brain and conventional treatments, respectively. The body frame localizer with sphere markers was tested first without the patient to assess the accuracy of positioning the couch-top automat- 260 Poster Abstracts
ically. The accuracy in positioning at AP-, LAT-, and SI-direction is within 0.2 mm. Two spinal patient’s setup on L4 –L5 and T11-T12 were also evaluated. The accuracy in positioning the updated isocenter in all directions is less than 0.5mm. The CRW head frame localizer with sphere markers was also evaluated with a head phantom. The accuracy of positioning the target isocen- ter to coincide with the radiation isocenter at different couch positions is less than 0.5mm. Using the leveling device, the couch-top could be leveled to be within 0.1 degree in tilt, yaw and roll directions for the patients received the treatment at the various anatomic sites.
Targeting accuracy of a novel image guided gating system for stereotactic body radiotherapy P2-32 Stephen, Tenn (1); Paul, Medin (1); Timothy D., Solberg (1) (1) UCLA Medical Center - Department of Radiation Oncology Los Angeles, USA INTRODUCTION: Targeting accuracy was evaluated for a novel image guided gating system (BrainLAB AG, Heimstetten, Germany) for stereotactic body radiotherapy (SBRT). METHOD: A solid water phantom containing five 2mm lead BBs was imaged with CT and reconstructed with 3mm slice thickness. CT data was used for planning and generation of digitally reconstructed radi- ographs (DRR). For irradiation, the phantom was placed on a platform capable of 2-dimensional movement (1.8cm superior-inferior and 1.2cm anterior-posterior) mimicking thoracic tumor motion. Infra-red reflecting spheres placed on the phantom were used by the system to track phantom movement. The moving phantom was localized at 3 different positions (10%, 50% and 90% anterior-posterior peak-to-peak amplitude) in the simulated breathing cycle using digital stereoscopic kV radiographs triggered appropriately by the gating system. Localization was done by fusing BBs in the kV radiographs with those in DRRs. Film was placed horizontally inside the phantom and exposed by our linac using a 5mm SRS cone under gated conditions. Fiducial pin marks in the films allowed the position of the gated fields to be compared to those of fields exposed in a non-moving phantom positioned by the same stereoscopic kV radiography system. The effect of both fast (3.6 second period) and slow (5.7 second period) motions on accuracy was investigated. RESULTS: Difference in average superior-inferior position between the static fields and the gated fields are as follows: 0.7mm for 10% level and slow motion, 1.1mm for 10% level and fast motion, 0.1mm for 50% level and slow motion, 0.1mm for 50% level and fast motion, 0.2mm for 90% level and slow motion, and 0.0mm for 90% and fast motion. The standard devi- ation of the difference is 0.1mm for all measurements. CONCLUSION: Our study demonstrates very high accuracy of this system which is necessary for SBRT of moving targets.
Comparison of five radiosurgery treatment planning techniques: Is it a case of "six of the one, half a dozen of the other?" P2-33 Hester, Burger (1); Audrey, Pentz (1) (1) Netcare Group of Hospitals - Medical Physics Division Johannesburg, South Africa Introduction: Planning comparison studies assess theoretical differences in treatment plans. The volume of normal tissue included in and immediate adjacent to the prescription isodose line, inte- gral dose to the brain, dose inhomogeneity and dose to critical structures may all contribute to the risk of complications. Five techniques were evaluated: Circular arc (collimators), conformal 261 Poster Abstracts
static beam, conformal arc, dynamic conformal arc and intensity modulated radiosurgery (micro- multileaf collimator). Methods: Eight cases were selected, based on shape and diameter: Roughly spherical < 3 cm, complex < 3 cm, complex > 3 cm and multiple lesions. Two were planned with all five techniques and the remainder with the conformal techniques only. A target volume was drawn in by the oncologist. Plans were renormalized to deliver 18 Gy to at least 99% of the target volume, with the exception of plan 5 (95%). The PITV, VNT50%, VNT25%, MDPD and DVHs were calculated. Plan 5 was rated by 31 oncologists and planners, indicating whether iso- dose data, DVH data or RTOG indices were used for evaluation. Results: Apart from the expect- ed difference in MDPD between multiple and single isocenter techniques, only small differences were observed, mainly with regard to VNT50% and VNT25%. Analysis indicated that 42% of oncologists based their assessment primarily on DVH data, 40% on isodose distributions and only 18% on RTOG criteria. Conclusion: Limited information can be obtained with the RTOG criteria alone. More detailed radiobiological analysis, combined with training, coordinated follow-up and observation of actual complications is required. A project has been launched to register all patients within the Netcare Group in South Africa on a national database to record predicted vs. actual complications. Cognitive testing using the Brain Resource Centre’s IntegNeuro system will assist in the assessment of cognitive function.
Feasibility of implanted fiducial markers for patient positioning for cranial radiotherapy P2-34 Rosa, Cañon (1); Ignacio, Azinovic (2); Mario, Lobato (2); Francisco, Garcia-Cases (2); Maricarmen, Heredia (2); Jose, Navarro (3); Jose, Martinez (2) (1) Hospital San Jaime - Oncology Platform, Radiation Oncology; (2) Hospital San Jaime - Oncology Platform, Radiation Oncology; (3) Hospital San Jaime - Neurosurgery Torrevieja, Spain Purpose: To assess the feasibilty and reliability of fiducial marker implantation for precise set-up and real-time positioning in patients with brain tumours treated with external beam radiothera- py. Methods and Materials: Between October 2003 and October 2004, 12 patient (p) with intracranial tumors were treated with external radiotherapy using implanted cranial gold markers. The procedure consisted in the insertion of 3 gold markers of 2 mm in diameter in the skull. Before treatment planning, immobilization with a thermoplastic mask was performed . Routine CT scan with intravenous contrast and Magnetic Resonance Imaging registration was used to identify the target volume. Before each fraction the patient was positioned on the treatment table and 2 orthogonal portal images were performed using an amorphous silicon panel to localize the 3 gold seeds and the target position was calculated using a comerzialized computer program (ISOLOC software, MED-TEC). This program provides the couch movements required to move the target to the isocentre. Results: Gold markers were implanted in 12 patients (5 women and 7 men, medi- an age 50,5 years range 28 – 74). Tumor histology was: 6 (50%) gliomas (primary 4 and 2 relapse after surgery, chemotherrapy and radiotherapy, then 2 re-irradiations), in 5 (41.7%) cases were brain metastases and 1 acoustic neurinoma. Patients were treated using 6 MV photons with 5 (3 – 7) non-coplanar beams, with conventional fractions in 4p (33,3%), hypofractionation in 6p (50%) and hyperfractionation in 2 p. When the setup error was corrected using the coordinates of the 3 markers, the final movements has been less than 2 mm in all cases. No serious compli- cations related to the gold markers insertion were noted. One patient treated with simoultaneous 262 Poster Abstracts
intracarothid chemotherapy suffered an unilateral aseptic meningitis, with complete resolution after the treatment. Conclusions: The use of 3 implanted fiducial is an optimal technique for pre- cise set-up in patients with brain tumors treated with external radiotherapy. This commercial sys- tem is highly suitable for fractionated stereotactic irradiation. Final adjustments are low using the current methodology based in anatomical references.
Dynamic extracranial robotic radiosurgery by means of a real-time motion correction system: Analysis of the reduction of the planning target volume compared to the static technique P2-35 Franco, Casamassima (1); Giovanni, Ambrosino (2); Paolo, Francescon (3); Carlo, Cavedon (3); Joseph, Stancanello (3); Stefania, Cora (3); Michele, Avanzo (3); Paolo, Scalchi (3) (1) University of Firenze - Department of Fisiopathology - section of Radiotherapy; (2) S. Bortolo Hospital - Vicenza - Italy - General Surgery Department; (3) S. Bortolo Hospital - Vicenza - Italy - Medical Physics Department Firenze, Italy Introduction: Spatial accuracy in extracranial radiosurgery is affected by organ motion. Static tech- niques require to enlarge the planning target volume (PTV) in order to guarantee tumour cover- age; PTV enlargement however implies irradiation of bigger volumes of organs at risk (OAR). Two possible solutions exist: 1) gated techniques, which allow smaller volumes to be irradiated but negatively affect treatment times; 2) dynamic strategies that can reduce irradiated volumes and preserve treatment times. In this work we report on initial experience in the use of the Synchrony dynamic device, an extension of the Cyberknife system. Method: We selected 7 extracranial treat- ments (2 liver, 4 lung, and 1 pancreas) performed before use of Synchrony for which we delin- eated the tumor volume in CT scans acquired in inspiration and expiration phases. We fused the two datasets and we delineated the PTV after join of the two contours. After acquisition of the Synchrony system we revaluated the plans by taking into account only one of the contours and we calculated 1) PTV volume differences, 2) 50% isodose volume differences and 3) difference in NTCP for organs at risk, using the Lyman model with correction for fractionation. Results: Volume reductions were 38% (average) for liver lesions, 43.9% (average) for lung targets and 8.5% for the pancreas treatment. Volumes of 50% isodose surfaces underwent similar percentage reduc- tion. NTCP reduction depends on the type of OAR. For lung NTCP was reduced from 2.5% to 0.1% (average), while for liver cases NTCP varied from 32% to 21% (average). Differences for the pancreas case were negligible. Conclusion: Significant volume reduction is obviously attained for targets located in proximity of the diaphragm. Reduced dose to OARs can be achieved by means of a real-time motion correction device, which opens the way to dose escalation. We estimated an advantage for OARs with parallel architecture, even if major differences could be expected for serial organs.
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Monte Carlo simulation for stereostatic treatment with multiple fields P2-36 Karl, Chan (1) (1) Prince of Wales Hospital - Physics Department of Radiation Oncology Shatin, Hong Kong The stereostatic treatment plans from Radionics Xknife RT3.0 are compared with Monte Carlo sim- ulation. The arc treatment is simulated by using multiple fields. Different cone sizes , Jaws and Non-jaws algorithm will be compared. Measurement results will be presented as well. The Monte Carlo code called MCBEAM from Fox Chase Cancer Centre in USA is used in this project. MCBEAM is EGS4 based code modified from BEAM code of NRCC. A computer program has been written to generate the multiple fields for the arc. Beam can be placed every 0.25°, 0.5° or 1.0° of the gantry. In this study, half-degree intervals was found to be a good approximation of the arc treatment.
The study of dose enhancement close to platinum implants for 4, 8, 14 and 18 mm collimator helmets in the Gamma Knife surgery P2-37 Joel Y. C., Cheung (1); C.P., Yu (1); Robert TK, Ho (1) (1) Canossa Hospital - Gamma Knife Centre Hong Kong, Hong Kong Introduction: Platinum objects are sometimes implanted into a human brain, such as the Guglielme Detachable Coil system, the Auditory Brainstem Implant, and the Deep Brain Stimulation. For patients who undergo gamma knife Surgery and who have platinum implants inside their brains within the treatment target, no specific guidelines or recommendations to min- imize the undesired effects to the surrounding critical structures were given. In this work, we cal- culated the dose enhancement close to a 4 mm diameter platinum implant when a single shot irradiation was made using the 4, 8, 14 and 18 mm collimator helmets. Methodology: The PRES- TA (Parameter Reduced Electron-Step Transport Algorithm) version of the EGS4 (Electron Gamma Shower version 4) MC computer code was employed. The platinum implant was placed at the unit centre point (UCP) and the single shot isocentre targeted at the UCP. Energy depositions sur- rounding the implant were scored and gave the absorbed dose. Results and Discussion: For the 8, 14 and 18 mm collimator helmets, the dose enhancements obtained are similar, which can be explained by the similar beam profiles with and without the platinum implant in the region from the maximum down to the platinum-phantom interface. On the other hand, the dose enhance- ment for the smallest 4 mm collimator helmet is higher than those using the 8, 14 and 18 mm collimator helmets, which can be explained by the rapid fall-off of the steep gradient of the dose profile without the platinum implant.
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Stochastic target approximation by auto-computation of spatial units for stereotactic radiosurgery P2-38 Kyoung-Sik, Choi (1); Seongjong, Oh (2); Hyun-Tai, Chung (3); Moon-Chan, Kim (4); Bo-Young, Choe (5); Suh, Tae-Suk (6) (1) The Catholic University of Korea, School of Medicine - Biomedical Engineering College of Medicine; (2) The Catholic University of Korea, School of Medicine - Biomedical Engineering College of Medicine; (3) Seoul National University Hospital - Department of Neurosurgery; (4) Kangnam St. Mary's Hospital - Neurosurgery; (5) The Catholic University of Korea, School of Medicine - Biomedical Engineering College of Medicine; (6) The Catholic University of Korea, School of Medicine - Biomedical Engineering Seoul, Korea An optimization plan can be generated using approximation algorithm with an improved tech- nique commonly applicable in a Linear accelerator and gamma knife for stereotactic radiosurgery. The two modalities in the radiosurgical plan were optimized by the conjunctions of many beam parameters in three dimensional space. In stereotactic radiosurgery, the dose distribution to adjust an intracranial tumor is produced from the spheres set on the unit isocenter or shot. This work mainly focused on two beam parameters of the isocenter location, the collimator size and points. One used a small collimator size considering the irregular boundary regions between the tumor and the normal tissue. In the other, an irregularly shaped tumor was approximated as a rectangular coverage and cubic structure to find the statistical distribution based on a 1„e1„e1 mm3 voxel. The results of applying the four imaginary targets fully acceptable to a radiosurgical plan conforming to Radiation Oncology Therapy Group (RTOG) guidelines; the prescription iso- dose line surrounding the targets was included in a more than 50% isodose curve. The dose con- formity was ordinarily acceptable and the dose homogeneity was always satisfied for various tar- gets (less than 2.0). This approach using stochastic algorithm is a useful radiosurgical plan with- out restrictions in the various tumor shapes and the different modalities.
Comparison of dose calculations and dose measurements near heterogeneities in gamma knife radiosurgery P2-39 Françoise, Desmedt (1); Stéphane, Simon (2); Bruno, Vanderlinden (2); Christophe, Vandekerkhove (2); Thierry, Gevaert (1); Bob, Schaeken (3); Daniel, Devriendt (4); Nicolas, Massager (5); Marc, Levivier (1) (1) Hôpital Erasme - Centre Gamme Knife; (2) Institut J. Bordet - Physique; (3) AZ Middelheim - Physique; (4) Institut J. Bordet - Radiothérapie; (5) Hôpital Erasme - Neurochirurgie Brussels, Belgium Purpose. The software used in gamma knife radiosurgery (Leksell GammaPlan®) doesn’t take into account the presence of heterogeneities in the skull. A linear attenuation coefficient of 0.063 cm-1 (water) is applied in dose calculation. But sometimes, targets are located close to bone structures or sinus cavities. The purpose of this study is to estimate if dose calculations are in good agreement with measurements in such areas. Methods. Measurements were performed on the head of an anthropomorphic phantom in stereotactic conditions. A CT scan was preliminary done and TL and Alanine detectors were placed in intracranial holes close to bone and aeric cav- ities. Different doses were prescribed on these areas, which were then irradiated in the gamma knife. Results. Preliminary measurements with TL dosimeters near bone structures give a meas- ured dose of 0.974 +/- 0.087 Gy for a prescribed dose of 1 Gy on a volume equivalent to TL detectors. The same measurements were performed with Alanine detectors for a prescribed dose 265 Poster Abstracts
of 10 Gy also near bone structures. The measurements give a dose of 11.304 +/- 0.127 Gy. Conclusion. Preliminary results show that TL measurements are in good agreement with dose cal- culations. Contrary to TL detectors, Alanine dosimeters are tissue equivalent which gives a better choice for phantom measurements. It is therefore interesting to perform an experimental compar- ison between these detectors. Temporarily, dose measurements with alanine are less close to dose calculations but more measurements have still to be performed and also close to aeric struc- tures. It might be also interesting to compare not only absolute doses but also the shape of cal- culated isodoses and measured isodoses on Gafchromic® films near heterogeneities.
Dynamic arc: useful or expensive toy for meningiomas treatment? P2-40 Frederic, Dessy (1); Carine, Mitine (2); Laurent, Gilbeau (1); Marie-Therese, Hoornaert (1) (1) Hôpital de Jolimont - Radiotherapie; (2) Jolimont hospital - Radiotherapy Haine Saint Paul, Belgium Purpose: To quantitatively compare treatment techniques: static, conformal fields and dynamic arc in stereotatic fractionated radiotherapy for meningiomas. Materials and methods: we report a case of a temporo-parietal meningioma (WHO grade 2) which occurred in a 64-year-old women. She was treated by fractioned radiotherapy using a Linac after a subtotal resection. The median target volume is 95, 6 cm3 and the dose delivered 57.6 Gy by fractions of 1.8 Gy five times week- ly. Stereotatic fractionated radiotherapy is delivered by a Varian clinac 2100C/D with a 120 leafs MLC photon beam 6 MV. The planning software is BrainScan 5.3. The drawing of all the struc- ture is made in Iplan 2 from BrainLab.Before the treatment of a patient using such a technique, we also realise a quality control of the dynamic arc module of the BrainScan 5.3 software. Using the IMRT Omnipro phantom form scanditronix and Kodak EDR-2 film. The planning is mapped to the phantom filled with slab of film, treated and the film was compare to the calculated dose using the Gamma factor as evaluation method. The dose distribution is planned in order to cover at least 95% of the target’s volume with the prescription isodose. The patient will be planned with the three different options (static filed, conformal arc and dynamic arc). In the fixed-field option and conformal arc, the MLC leaves remain static during the irradiation and in the dynam- ic arc technique, the leaves are dynamically moving to match the changing shape of the target projection. We will study the difference in DVH for the total irradiated volume, PTV and critical organs (brainstem, chiasma, cranial nerves) and also use the of conformity index, minimum tar- get dose for different plan corresponding to the following specification. We also study the influ- ence of the prescription isodose (50 %, 80 % and 90%) on the different PTV.
Simultaneous SRS for multiple intracranial lesions with single isocenter using micromultileaf collimator P2-41 Junichi, Fukada (1); Etsuo, Kunieda (1); Osamu, Kawaguchi (1); Satoshi, Seki (1); Naoyuki, Shigematsu (1); Minoru, Uematsu (1); Atsushi, Kubo (1) (1) Keio University - Department of Radiology Tokyo, Japan Introduction: Most of multileaf collimator devices consist of only one layer of leaves so that it is difficult to produce multiple “holes” in one treatment field. Micromultileaf collimator (MMLC)) which has two banks of leaves perpendicular to each other is capable of producing a treatment 266 Poster Abstracts
field with multiple “holes” corresponding to multiple targets, though it has limitations to some extent. Therefore, it is possible to treat multiple lesions adjacent to one another with one isocen- ter. We report some cases in which multiple close lesions were treated with stereotactic radio- surgery simultaneously with a single isocenter. Cases and methods: 4 cases with multiple lesions were treated with a single isocenter. They included three cases of metastatic brain tumors and one case of atypical meningioma. One case of metastatic brain tumor and one case of meningo- ma had undergone surgical removal previously. A 6-MV linear accelerator (Linac, ML15MV: Mitsubishi Electric Corp. Tokyo, Japan) was used to produce the x-ray beam. An MMLC module (AccuLeaf: Alayna Enterprises Corporation, Paris, France) was mounted on the linac gantry-head. MMLC has leaves arranged on two levels perpendicular to each other. The effective leaf width of the inner pairs is 2.6mm at the isocenter while it is 4.5mm for the outer pairs. We treated 2 lesions simultaneously in one case of metastatic brain tumor and postoperative meningioma. We treated 3 lesions with a single isocenter in two cases of metastatic brain tumors. Estimated tar- get volume of 4 cases are 8.91cc, 3.27cc, 3.49cc, 0.90cc. We simulated planning, treating each target independently, measuring the distance from one target center to another, and evaluating the homogeneity and conformity indices. Results: All treatments were completed with no adverse events. The treatment time can be shortened. Distance between one target center and another ranged form 41.7 mm to 8.1mm. Simultaneous SRS showed acceptable results in homogeneity and conformity, though lower conformity was observed in the simultaneous SRS for 3 lesions. Conclusion: If multiple lesions are adjacent to one another, simultaneous SRS were able to com- plete safely with MMLC and achieve sufficient conformity. With simultaneous SRS, we can treat in shorter time and reduce patients burden and deal with multiple lesions. From that aspect, simultaneous SRS has clinical efficacy.
A new tool for quantitative evaluation of plan quality in Fractionated Stereotactic Radiotherapy P2-42 Janna, Menhel (1); Dror, Alezra (1); Rafael, Pfeffer (1); Roberto, Spiegelmann (2) (1) Sheba Medical Center - Department of Oncology; (2) Sheba Medical Center - Department of Neurosurgery Ramat Gan, Israel Objective: To evaluate differences between IMRT and Dynamic Arcs (DA) for Fractionated Stereotactic Radiotherapy (FSR) using a novel approach for plan evaluation. Methods: 17 cases of cavernous sinus meningioma were evaluated. In all cases the tumor compressed the optic pathways, the major organ at risk (OAR). DA consisted of 4 dynamic arcs and IMRT included 12 beams (BrainLab ver. 5.21). Optic pathway dose was aimed to be limited to 2 Gy/fraction. The comparison analysis included both dose and volume–related target coverage (dTC and vTC), PITV (RTOG, 1993), Conformity Index (CI, Lomax) and Conformation Number (CN, Van't Riet) values. We developed and implemented a novel evaluation criterion, Critical Organ Scoring Index (COSI), defined as: [1-VTol/vTC], where VTol is the partial volume of OAR receiving over tolerance dose. This parameter approaches unity when the critical structure is completely spared, and target cov- erage is 100%. Deviations will yield lower values of COSI. We present a new 2D graphical rep- resentation of COSI versus CI, which improves our ability to assess trade-offs of the different plans in a simple visual way. Results: For optic pathway volume, receiving over 50Gy average COSI val- ues for DA and IMRT were 0.889 and 0.896 respectively. There were no significant differences in any scoring indices between the two approaches. However, COSI-CI plots revealed that IMRT was 267 Poster Abstracts
superior in 47% and inferior in 17.5% of cases. For the remainder, both treatment approaches were equivalent. Conclusions: For all conformity score functions plan quality was acceptable for both DA and IMRT approaches. The novel COSI method we developed proved to be consistent with other conformity score functions, and was highly efficient in assessing specific structure spar- ing. COSI-CI plots can be expanded to include multiple OARs, as relevant for a particular treat- ment site, enabling reliable visual assessment of different plans.
Characterization of lung lesion doses in Stereotactic Body Radiation Therapy (SBRT) via Monte Carlo P2-43 Premavathy, Rassiah (1); Martin, Fuss (2); Bill J., Salter (3) (1) UTHSC San Antonio - Radiology; (2) UTHSC San Antonio - Radiation Oncology; (3) Cancer Therapy & Research Center - Medical Physics San Antonio, USA Stereotactic Body Radiation Therapy (SBRT) represents an exciting new delivery paradigm in which hypofractionated, extremely conformal dose distributions is delivered. Determining the optimal dose and fractionation scheme, requires an understanding of the true delivered radiation dose and, thus, an accurate understanding of the dosimetry in the inhomogeneous and very low- density-environment of the lung. This study attempts to accurately characterize the doses received by static targets located in the lung, as well as doses to critical structures for the serial tomother- apeutic intensity-modulated delivery method used for SBRT in our clinic. 76 NSCLC patients have been treated with SBRT between 2001–2004 with, a standard prescription dose for lung metas- tases of 36 Gys in 3 fractions delivered every 48 hours and primary lung neoplasms (stage 1 NSCLC) between 3 times 16 Gy to 3 times 20 Gy. Dose distributions previously planned on a con- ventional planning system were recalculated using a Monte Carlo (Peregrine pre-release version) which is accurate to better than .3% in an anthropomorphic phantom. 10 of the 76 SBRT patient data sets are presented here. The mean CTV volume of the lesions presented here is 40.1 cm3 (4.7 cm3 –99.8 cm3). The conventional algorithm overestimates the mean dose to the CTV for all lesion volumes by an average of 14.1 % of prescribed dose (range: 6.6 %- 25.1 %) compared to MC calculation. This overestimation is greater for small lesions, where the 25.1 % of over-pre- diction corresponds to the smallest lesion (4.7 cm3), demonstrating that an accurate modeling of electronic equilibrium conditions is most important for small lesions. The largest discrepancies exist for both the Maximum and Minimum doses to critical structures (lungs, spinal cord, esoph- agus and the major airways), with mean doses in better agreement. Statistical analysis of all 76 patients is underway and will be presented.
In SRS treatment what factors affect the normal tissues receiving doses much less than prescription doses? P2-44 Ramaswamy, Sadagopan (1); Narayan, Sahoo (2) (1) M.D. Anderson Cancer Center - Radiation Oncology; (2) M.D. Anderson Cancer Center - Radiation Physics Houston, USA In this study, we investigate two factors that influence the volume of normal tissues receiving low doses, specifically, 70,50 and 30% of the prescription dose. The two factors that studied were the target volumes and the average depth of the target. A plastic head phantom filled with water was used with speherical targets of various sizes simulating the typical metastatic lesions seen in 268 Poster Abstracts
radiosurgery treatments. Treatment plans were done using Radionics treatment planning soft- ware resulting in four 90 degree arcs at four different couch angles. The planning process used is simillar to that employed in our clinic, aiming for minimum achievable TVR, isodose coverage with atleast 80% dose with respect to isocenter. However, the presence of critical structures is ignored in this study. As expected, our study indicated that the volumes of tissues receiving 70, 50 and 30% prescription dose is correlated directly with tumor volume and the relationship is not linear. A fourth order polynomial seems to fit all 70,50 and 30% dose volume with target volume with a coefficient of variation ( r^2) 0.998 or better. The volumes of normal tissues receiving low doses did not vary with the average depth of target as it varied from 8cm to 4cm.
Dosimetric verification of an IMRS dose delivery of the Novalis system P2-45 Dong-Joon, Lee (1); Moon-Jun, Sohn (1); Sung Rok, Han (1); Sang Won, Yoon (1); Gee Taek, Yee (1); C. Jin, Whang (1) (1) Inje University - Ilsan Paik Hospital - Department of Neurosurgery Goyang, Korea INTRODUCTION IMRS(Intensity Modulated Radiosurgery) is an effective treatment option that has been applied in OAR(Organ At Risk) closed lesion. We evaluate the dosimetric accuracy in the process of IMRS commissioning of Novalis (BrainLAB AG, Heimstetten, Germany) METHODS A small water phantom(SWP) include well shape target lesion was designed for evaluate the dose delivery and distributions of the prescribed IMRS plan. To verify the dose delivery, special dosime- ters were placed at the OAR region and 20 Gy dose was delivered to the isocenter. Farmer type ionchamber (0.6cc) and 9 number of TLDs were irradiated to determine the absorbed dose in a few typical points. And the monochromic films(GAFCHROMIC Dosimetry Type MD-55, Victoreen, USA) were irradiated in the SWP to verify the 3D dose distribution. And MapCheck 1175 2D- diode array was used for the planned 9 beam fields to verify the dose distributions. The several treatment plan techniques including IMRS were adopted and compared for this study. Non-copla- nar 9 beams were used for IMRS treatment and the intensity modulated beams were delivered through the sliding window technique using mMLC. RESULTS The experimental set up of SWP allows to evaluate the dose delivery and dose distribution. Spatial localization accuracy was found to be smaller than ±1.0 mm and the dose delivery difference of measured dose and cal- culated dose was within ±1.5 %. And dose–difference distribution of superimposed isodose (measurement-calculation) values were within ±5.0 %. CONCLUSION For the comparison of using other treatment plan technique, only the IMRS treatment plan can save the OAR complete- ly. And dosimetric accuracy of the IMRS plan using single slice delivery showed that dose distri- bution was good agreement in high dose and low dose gradient regions.
Multiple isocentric plan with Brain Lab microMLC for eight brain mets P2-46 Dinesh, Tewatia (1); S.K., Rout (1) (1) Indraprastha Apollo Hospital - Medical Physics New Delhi, India In this paper we have evaluated the possibility of treating multiple brain mets with the help of BrainLab microMLC(52 leaf). The patient after receiving 40Gy of whole brain dose came with mul- 269 Poster Abstracts
tiple brain mets(eight) for irradiation. The treatment of choice for the patient was Sterotactic Conformal beams(SRT) with the help of BrainLab M3 system. Treatment plan for the patient gen- erated with combination of both coplanar and noncoplanar beams. The goal treatment planning was to encompass 90% dose to PTV while minimizing dose to other critical structers and normal brain.The following parameters are evaluted: target conformity,target homoginiety,normal tissue receieving doses>80%,>50%,and >20%.The plan showed a good confomity of the dose dis- tribution with all brain mets.In this study static conformal beam showed significant dosimetric inprovement than conformal dynamic arc planning.
An analysis of the impact of intrafraction internal anatomy motion on delivery of radiation therapy: A dosimetry analysis using a dynamic phantom system P2-47 Chung, Jin-Beom (1); Suh, Tae-Suk (2); Chung, Won-Kyun (3) (1) The Catholic University of Korea, School of Medicine - Biomedical Engineering; (2) The Catholic University of Korea, School of Medicine - Biomedical Engineering; (3) Seoul Health College - Radiation Science Seoul, Korea Respiratory motion in the thorax and abdomen is an important limiting factor in high-precision radiation therapy. The lung tumor and tumors (liver, pancreas, stomach) in abdomen therefore are internal motion due to breathing. We will perform to measurement and analysis of a delivered dose distributions for these moving tumors. In preliminary study, we investigated the displace- ment of moving tumors in the abdominal regions such as liver, lung with previously reported papers. With analytical motion model described by Lujan et al., internal motion of organ was reproduced with phantom and moving control device (MCD), which appear three dimensional (3- D) motions such as x, y and z axis. The Dynamic phantom system was used to assess the deliv- ered dose distribution of organ with and without internal motion under similar condition, although there are not the same internal organ motion. In this study, Kodak X-Omat film was used to measure dose distributions. Difference of dose distribution to motion of internal organ was observed. Little difference appeared in maximum doses. But minimum doses of difference in dose distribution irradiated on moving tumor are apparently higher than 10%. The dose distribution for moving organ was also increased more than 10 mm of the penumbra region during respira- tion. In future, we will obtain the exact evaluation of dose distributions if improved in programed software of moving control device and measure precise internal motion using image modality such as fluoroscopy, simulator in based on this study.
Dynamic field shaping arc versus circular cones for treatment of AVM: a comparative study P2-48 Carole, Gallez (1); Dirk, Verellen (2); Koen, Tournel (3); Nadine, Linthout (4); Tom, Wauters (5); Jean, D'Haens (6); Guy, Storme (7) (1) VUB - ETRO; (2) AZ VUB - Physique; (3) AZ-VUB - Radiotherapy; (4) AZ-VUB - Radiotherapy; (5) AZ-VUB - Radiotherapy; (6) AZ-VUB - Neurosurgery; (7) AZ VUB - Radiothérapie Brussels, Belgium Background and Purpose: To investigate the influence of beam collimation in linac-based stereo- tactic radiosurgery (SRS) of arteriovenous malformations (AVM) comparing circular cones and micro multileaf collimation (mMLC). Material and Methods: A comparative planning study 270 Poster Abstracts
(BrainSCAN v 5.2, BrainLAB, Germany) has been performed on 2 types of AVM: (a) a spherical lesion (0.78 cm3) and (b) an irregular shaped lesion (11.11 cm3). A prescription dose of 20 Gy (80%) has been defined to encompass the target volume. A single isocentric dynamic field shap- ing arc therapy (DFSAT) technique using a mMLC has been compared to single and multi-isocen- tric arc techniques (2,3,4 and 5 isocenters, with varying cone diameters) using circular cones (CCT). A linac dedicated for radiosurgery (NOVALIS system, BrainLAB, Germany) has been used for all planning simulations. The total amount of Monitor Units (MU), Conformity Index (CI: defined as the ratio of target volume encompassed by the 80% prescription isodose with the total volume of tissue encompassed by the 80% prescription isodose) and Dose Heterogeneity (DH: defined as the ratio of the difference of the maximum dose and the minimum dose to the target volume to the median dose to the target volume) have been evaluated. Results: For the spherical lesion, comparable results have been obtained between both treatment techniques with a slight advan- tage for CCT (respectively for CCT and DFSAT: CI 4.70 and 5.34; DH 0.10 and 0.16; 3499 MU and 3550 MU). For the irregular shaped lesion, the CI seemed superior for CCT compared to the DFSAT (on average 1.31 compared to 3.25) due to underdosage of the lesion (minimal target dose between 10.75Gy and 16.50Gy for CCT versus 20.50Gy for DFSAT). This is confirmed in the DH: ranging between 0.88 and 1.14 for CCT and 0.26 for DFSAT. The latter is also reflected in the max- imum dose: ranging between 37.25Gy and 49.00Gy for CCT versus 26.75Gy for DFSAT. The sin- gle isocentric DFSAT required 3360 MU whereas a 5 isocenter CCT required 15026 MU for the same target dose. Conclusions: For spherical lesions the CCT and DFSAT yield comparable results with a slight advantage for the CCT. The CCT is significantly inferior compared to DFSAT for the irregular shaped lesion, both with respect to treatment efficiency and target coverage.
Gamma knife surgery for functioning pituitary adenomas extending into cavernous sinus: Advantages in robotized micro-radiosurgery with advanced MR iImaging P2-49 Motohiro, Hayashi (1); Masahiro, Izawa (1); Taku, Ochiai (1); Koutaro, Nakaya (1); Tomokatsu, Hori (1); Kintomo, Takakura (1); Jean, Regis (2) (1) Tokyo Women's Medical University - Department of Neurosurgery; (2) CHU La Timone - Service de Neurochirurgie Tokyo, Japan Rationale: Tumors which are extending into the cavernous sinus (CS) are difficult to be safely removed by microsurgery. Gamma knife surgery (GKS) has played important role as an alternative treatment for CS tumors without any significant complication. Since 1999, new gamma knife sys- tem with APS (Automatic Positioning System) has been refined with advantages. Additionally, sequences of MRI have developed dramatically, that 0.5-1.0mm thickness with the highest qual- ity can be possible to perform, and provided us to complete more accurate dose planning for pitu- itary functioning adenomas to suppress tumor progression and activity. Method: Frame applica- tion should be parallel to the optic pathway. We should select some original sequences of MRI dedicated to the pituitary adenomas extending into the CS. In the treatment of functioning ade- nomas, precisely tumor visualization must be the most important, and relationship to the vital structures should be also elucidated. Adenomas should be involved perfectly within 50% isodose line with highly conformity/selectivity in avoidance to the excessive irradiation dose to the not only optic pathway, but also normal pituitary glands and lateral wall of CS with 0.1mm level 271 Poster Abstracts
adjustment. Consequently, we should pay attention for the occupied percentage of 80% isodose line area to be as much as possible to expect tumor shrinkage and improve /normalize endocrino- logically. Results: We have treated 50 cases with pituitary adenomas using only new GKS with APS. 26 adenomas, including 16 functioning adenomas, could be evaluated at least 1 year fol- low-up. Tumor control rate achieved in 100%, and observed much shrinking in 62.5%. 75% patients experienced endocrinological improvement, and observed nearly normalization (only base line value) in 43.8%. In particular, the patients with Cushing disease experienced more effec- tive than before, in spite of quite short time follow-up. No patient has complained any complica- tion. Conclusions: We have demonstrated to establish the optimal dose planning with APS. Of course, longer term follow-up should be need. But, we already experienced some satisfied results with the treatment concept and strategy as “Robotized Micro-radiosurgery”.
Efficacy of gamma knife radiosurgery in patients with recurrent or residual functioning and non functioning pituitary adenomas P2-50 Mercedes, Heureux (1); Bich-Ngoc-Thanh, Tang (2); David, Wikler (2); Nicolas, Massager (3); Marc, Levivier (4); Bernard, Corvilain (1) (1) Hôpital Erasme - Endocrinology; (2) Hôpital Erasme - PET Scan; (3) Hôpital Erasme - Neurochirurgie; (4) Hôpital Erasme - Centre Gamme Knife Brussels, Belgium The goal of this study was to examine the potential benefit of gamma knife radio surgery (GKS) in postoperative patients with recurrent or residual functioning and non functioning pituitary adeno- mas. 20 cases of residual pituitary adenoma visualised by RMN and/or PET with 11C-methionine (PET-Met) and treated with GKS were analysed. 5 were non functioning adenomas, 6 adrenocor- ticotropic adenomas, 7 prolactinomas, 1 somatotropic adenomas and 1 plurihormonal adenomas (GH+PRL). The treatment was justified either by the persistence of uncontrolled hypersecretion or by the regrowth of the residual tumour. PET-MET was combined with MRI for GKS targeting. The mean tumour volume was 2.76 ± 2.32 cm3 (range 0.15-6.7). The mean dose was 18.6 Gy (range14-20) for non functioning pituitary adenomas and 28.2 Gy (range 18-35) for functioning pituitary adenomas. The mean follow-up duration was 36 ± 17months (range 15-57). We assessed the effects of GKS on (1) tumour growth (2) control of hormone hypersecretion (3) occur- rence of pituitary insufficiency. Adequate follow up was unavailable in 2 patients. Tumour growth (defined as no further growth) was controlled in 94.1 % of the cases and tumour shrinkage (defined as tumour decreased) occurred in 76.4%. Reduction of hormonal hypersecretion was observed in 69.2 % of the cases and 14.2 % of cases were considered as cured. The results were not different according to the type of hypersecretion. 2 patients had panhypopituitarism before GKS. After irradiation, patient endocrine function was studied every 12 months. Some level of pituitary insufficiency was observed in 7/16 patients (43.7 %). This was mainly observed in patients treated for large residual pituitary tumours. In this small series, the most vulnerable axis is the somatotropic axis, followed by the gonadotropic, the corticotropic and thyrotropic axis. No other adverse effects were observed. In conclusion, this study suggests that GKS is a safe and effective therapy in selected patients with residual and recurrent pituitary adenomas. Longer fol- low-up is required for a more complete assessment of late toxicity and treatment efficacy.
272 Poster Abstracts
Clinical results of LINAC-based stereotactic radiosurgery and Fractionated Stereotactic Radiotherapy for pituitary adenomas P2-51 Putipun, Puataweepong (1); Mantana, Dhanachai (1); Puangtong, Kraiphibul (1); Lucksana, Pochanugool (1); Somjai, Dangprasert (1); Jiraporn, Laothamatas (1); Veerasak, Theerapancharoen (2); Suchart, Phuthichjaroenrat (3); Pornpan, Yongvithisatid (1); Kanjana, Boonpitak (1) (1) Ramathibodi Hospital Mahidol University - Department of Radiology; (2) Ramathibodi Hospital Mahidol University - Department of Surgery; (3) Prasat Neurological Institute - Pathology Bangkok, Thailand ABSTRACT Objective : To evaluate the clinical results of stereotactic radiosurgery (SRS) and frac- tionated stereotactic radiotherapy (FSRT) for pituitary adenomas with regard to tumor control and complications of the treatment. Methods: There were 51 patients with pituitary adenoma who underwent SRS or FSRT between November 1997 and October 2003. Of these, 12 received SRS and 39 received FSRT. The median tumor volume was 1.6 ml for SRS and 11.3 ml for FSRT. Ten of the SRS and 11 of the FSRT patients were hormonally active at the time of the initial diagno- sis. Both SRS and FSRT was performed using a Linac-based radiosurgery system. Median average dose was 15.8 Gy for SRS and 54.6 Gy for FSRT. Result : Median follow-up time was 4.7 (1.5- 7.4) years. The five-year overall tumor control rate was 96% (92% for SRS and 97% for SRT). Two patients with ACTH secreting adenomas had local failure, one had an endocrinologic and radio- logic recurrence 15 months after SRS and subsequently had repeat surgery followed by FSRT. The other one had endocrinologic recurrence 20 months after FSRT which required additional bilater- al adrenalectomy. Hormonal normalization was achieved in 61%. Both SRS and FSRT showed similar responses with the average time to hormonal normalization of 12 months. There were no late severe complications except for pituitary deficiency. The incidence of endocrinologic adverse effects was similar in the two groups. The 3- year rate of freedom from newly initiated hormon- al replacement was 80%. Conclusion : Both SRS and FSRT achieved a similar high local control rate without severe complication.
Gamma surgery in the treatment of nonsecretory pituitary macroadenomas P2-52 Jason, Sheehan (1); Ladislau, Steiner (2); Vincezo, Mingione (3); Edward R., Laws Jr. (1); Mary Lee, Vance (2); Chun-Po, Yen (2); Melita, Steiner (2); Matei, Stroila (2) (1) University of Virginia - Department of Neurosurgery; (2) University of Virginia - Neurosurgery; (3) University of Vienna - Department of Neurosurgery Charlottesville, USA Objective: A retrospective analysis of the imaging and clinical outcomes following Gamma sur- gery in 100 nonsecretory pituitary macroadenomas is presented. Methods: From June 1989 to March 2004, 100 consecutive patients with nonsecretory pituitary macroadenoma were treated at the Lars Leksell Center for Gamma Surgery at the University of Virginia. Ninety-two tumors were macroadenoma residuals following one or multiple surgical procedures; in 8 patients, the Gamma surgery was the primary treatment. Ten patients received conventional fractionated radiotherapy before gamma knife. Sixty-nine patients had replacement therapy for one or more hormonal deficits. Peripheral doses between 5 to 25 Gy (mean 18.5 Gy) were given. The dose to the visu- al pathway never exceeded 8 Gy. Results: Imaging and endocrine follow-up was available in 90 patients ranging from 6 to 142 months (mean 44.9 months) and 6 to 127 months (mean 47.9 273 Poster Abstracts
months), respectively. Tumor volume decreased in 59 patients (65.6%), remained unchanged in 24 (26.7%) and increased in 7 (7.8%). The minimum effective peripheral dose was 12 Gy. Peripheral doses above 20 Gy did not seem to provide additional benefit. The median time for shrinkage of the tumor was 9 months. Following Gamma surgery, of 69 patients with a partially or fully functioning pituitary gland, 12 (19.7%) developed new hormonal deficits. For patients with endocrine follow-up longer than 2 years, the rate of new deficits was 25%. Conclusions: Present experience suggests that Gamma surgery is an appropriate management in aggressive nonsecretory pituitary macroadenoma residuals or recurrences following microsurgery and as a primary treatment in selected patients.
Results of steretoactic radiosurgery in patients with functional pituitary adenomas P2-53 Fabiola, Flores Vazquez (1); Pomponio, Lujan Castilla (2); Fiacro, Jimenez-Ponce (3); Francisco, Velasco (4); Mario, Enriquez (5); Luis, García (6); Eduardo, Arana (7) (1) Hospital General de Mexico - Radiotherapy; (2) Hospital General de Mexico - Radiotherapy; (3) Hospital General de Mexico - Neurosurgery; (4) Hospital General de Mexico - Neurosurgery; (5) Hospital General de Mexico - Radiotherapy; (6) Hospital General de Mexico - Neurosurgery; (7) Hospital General de Mexico - Radiotherapy Mexico City, Mexico Oversecretion of hormones from pituitary adenomas result in significant morbidity and reduce life expectancies for affected patients. surgical resection , is able to normalize hormone levels rapid- ly for 57 a 91% of patients. Unfurtunately, patients with persistent or recurrent endocrinopathies after surgical resection achieve biochemical remission less frecuently after repeated surgery. frac- tioned external beam radiation therapy results in clinical remission of symptoms for many patiens with hormone secreting tumors. nevertheless, radiotherapy frecuently causes hypothalamopitu- itary dysfunction, and is associated with the risk of radiation - induced neoplasms. methods: between 2000 - 2002, 14 patients with functional pituitary adenomas underwent radiosurgery: 11 patients with tumors that produced prolactina, and 3 with growth hormone producing tumors. in the prolactinoma patients, the mean target volume was 2.7 cm. In the acromegalic patients, the mean target volume was 2.9 cm.The mean patient age was 36 years. 100% had undergone surgery earlier. the median follow up period after radiosurgery was 36 months. Results: endocrine normalization or "cure", was definided as the finding of normal or below normal hormone levels. In 10 patients there was normalization of hormones secretion within the first 12 months, all this patients had prolactinoma tumors, 4 mores patients improved and normalized within the next six months. The mean radiation dose directed to the tumor was 20 Gy. calculated dose to the adja- cent optic apparatus was less 8 Gy . after 36 months of follow up 6 patients, with prolactinomas less than 40 mm in diameter underwent an elevation from hormone levels. A new anterior pitu- itary deficiency developed in3 patientes (21%). Conclusions: surgical resection should remain the initial primary treatment for the majority of patients with hormone productin pituitary adenomas. Nonetheless, radiosurgery provides biochemical remission for many patients with persistent or recurrent hormone oversecretion syndromes caused by tumors size or location.
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Gamma knife radiosurgery for secretory and non-secretory pituitary adenomas P2-54 Aditya, Gupta (1); Sandeep, Vaishya (1); S S, Kale (1); V S, Mehta (1) (1) All India Institute of Medical Sciences - Neurosurgery Department New Delhi, India Gamma knife Radiosurgery is widely used for the treatment of a variety of brain lesions. In this study we evaluated the efficacy of gamma knife Radiosurgery for primary and adjunctive treat- ment of pituitary adenomas, both hormonally secretory as well as non-secretory. 150 patients with pituitary adenomas were treated starting 1997 May. Of these, 40 were treated primarily and the rest (except one) had undergone surgical decompression prior to gamma knife. Non-function- ing adenomas constituted the largest group, with 60 patients. The secreting adenomas were treated with a mean margin dose in the range of 27-35 Gy whereas the nonfunctional ones were given margin doses in the range of 10-12 Gy. RESULTS: In the Non-functional group, follow up was available for 36 patients, of whom 19 had reduction or disappearance of tumor with the tumor remaining stable in the rest 17 patients. In the GH secreting tumors, the endocrine follow up was available for 26 patients of which all had decline or normalization in levels except 2. The radiologic follow up in this group was available for 14 patients, 9 of which showed a shrinking or disappeared tumor. In the Prolactinoma group, endocrine follow up was available for 18 patients of which 10 demonstrated significant decrease or normalization. Radiologic follow up was available for 15 patients all of whom showed a decrease in size or disappearance. In the ACTH group, follow up was available for 4 patients, 2 of which demonstrated both a decline in ACTH levels as well as tumor size. The 2 remaining patients had a stable tumor size with high ACTH levels. No significant side effects or radiation induced complications were seen in any patient. CONCLUSIONS: gamma knife Radiosurgery provided safe and effective treatment for both secretory and non-secretory pituitary adenomas treated primarily or adjunctively.
The radiosurgery for nonfunctioning pituitary adenomas P2-55 Yoshiyasu, Iwai (1); Kazuhiro, Yamanaka (1); Katsunobu, Yoshioka (1) (1) Osaka City General Hospital - Department of Neurosurgery Osaka, Japan Object: We evaluated the effectiveness of gamma knife radiosurgery in the treatment of nonfunc- tioning pituitary adenomas. Methods: We treated 34 patients with nonfunctioning pituitary ade- nomas between January 1994 and December 1999. Thirty-one of these patients were followed for greater than 30 months. The mean age was 52.9 years. All patients underwent resection prior to radiosurgery. In four patients, treatment was performed with staged radiosurgery. The treat- ment volume was 0.7 to 36.2 cm3 (median 2.5 cm3). The treatment dose ranged from 8 to 20 Gy (median 14.0 Gy) to the tumor margin. In 15 patients (48.4%), the tumor either compressed or was attached to the optic apparatus. The maximum dose to the optic apparatus was from 2 to 11 Gy (median 8 Gy). Results: Patients were followed for 30 to 108 months (median 59.8 months). The tumor size decreased in 18 patients (58.1%), remained unchanged in 9 patients (29.0%), and increased in four patients (12.9%). The 5-year actual tumor growth control rate was 93%. Among patients with tumor growth, two cases were secondary to cyst formation. Two patients (6.5%) required adrenal and thyroid hormonal replacement during the follow-up period after radiosurgery due to radiation-induced endocrinopathy. None of the patients suffered from 275 Poster Abstracts
new cranial nerve deficits, which included optic neuropathy. Conclusion: In this series, radio- surgery had a high tumor growth control rate during the long-term follow-up period. Furthermore, we observed a low morbidity rate with endocrinopathies and optic neuropathies. This low rate even included cases in which the tumor compressed or was attached to the optic apparatus. We emphasize the necessity of long-term follow-up to evaluate late complications.
LINAC stereotactic radiosurgery for pituitary adenomas P2-56 Martin, Malacek (1); Juraj, Steno (2); Ludmila, Trejbalova (3); Augustin, Durkovsky (4) (1) St. Elisabeth Cancer Institute - Department of Radiosurgery; (2) Faculty Hospital of the Comenius University - Department of Neurosurgery; (3) Faculty Hospital of the Comenius University - Department of Endocrinology; (4) St. Elisabeth Cancer Institute - Department of Radiology Bratislava, Slovakia Material/methods: 54 patients underwent the LINAC radiosurgery (LRS) for pituitary adenoma (PA): 23 endocrine-inactive PA, 19 growth hormone secreting PA (GH-PA), 8 adrenotorticotropic hormone secreting PA (ACTH-PA = 6 Cushing’s diseases, 2 Nelson’s syndromes) and 4 prolactin- omas during 12 years. In 17 cases with GH-PA we irradiated residual tumor (after pituitary sur- gery), 2 patients underwent primary radiosurgery, one of them without complete irradiation of the target volume. Thus only 18 cases with GH-PA are discussed. In other patients, we irradiat- ed residual tumor. The mean marginal dose was 17.8 (12–28) Gy, the irradiation of visual path- ways never exceeded 8 Gy. The mean follow-up was 62.3 months. During the clinical examina- tions, radiological changes of tumor, elevated hormone-response rate (RR), pituitary function and vision were observed. Results: The tumor growth was controled in 96.3% of patients. Three worsenings of previously deteriorated vision and 5 deteriorations of postsurgically preserved pitu- itary function were found during the follow-up period. Complete GH-RR or a partial one with “safe” GH serum levels (under 2 ng/ml) were found in 38.9 % (7patients) and the partial GH-RR only with “unsafe” GH serum levels (more than 2 ng/ml) in 61.1 % (11patients). One LRS had to be repeated (finally with complete GH-RR). Only partial ACTH-RR has been achieved in all cases with Cushing’s disease. Their overall follow-up was shortened due to two deaths. The prolactine- RR was also only partial. Conclusion: LRS is safe supplemental treatment of pituitary surgeries. The tumor growth control is good. 39.9 % of partial GH-RR with “safe” GH serum levels, 100% of partial ACTH-RR and prolactine-RR are less satisfactory. Some elevation of marginal doses could improve our results.
Using a small diode detector for a quick quality assurance (QA) test of the Cyberknife system P2-57 Anthony K., Ho (1); Steven D., Chang (2); John R., Adler Jr. (3); Cristian, Cotrutz (4); Iris, Gibbs (5) (1) Stanford University - Radiation Oncology; (2) Stanford University - Neurosurgery; (3) Stanford University - Neurosurgery; (4) Stanford University - Radiation Oncology; (5) Stanford University - Radiation Oncology Stanford, USA INTRODUCTION: Routine QA is done regularly for our Cyberknife System, using both thermolumi- nescence detectors (TLD) and Gafchromic films. Although both methods do a good job, it takes a few hours to perform the procedure. As a result, a faster method is needed for testing the whole system. METHODS: A small diode approximately 3 mm length and 3 mm diameter is used in this study. A hole was drilled in a small tissue equivalent cube (6.35cm x 6.35cm x 6.35cm) to accom- 276 Poster Abstracts
modate the diode, and three fiducials were implanted in the cube for tracking purposes. A small 5 mm collimator is used, and treatment planning is done with only 5 beams to deliver approxi- mately 100 cGy to the diode. RESULTS: Tests were first done to determine if this QA test is feasi- ble. 100 cGy was delivered to the approximate center of the diode. The block that housed the diode was then moved 1 mm from that center. The diode readings for those points 1 mm away from the center were about 90% of the reading at the center. This indicates that it is possible to use the setup to determine the accuracy of delivery the dose to within about 1 mm. Since diode sensitivity decreases with cumulated dose, a jig is used to calibrate the diode every time this QA procedure is done, with a 60 mm collimator. The readings using the mini phantom are normal- ized. CONCLUSIONS: The present study shows that this particular diode can detect system accu- racy to within 1 to 2 mm, and the QA procedure can be done in less than 10 minutes. This method of using a small diode can be used for routine or quick check of the entire Cyberknife system. This one procedure checks treatment planning, the robot, imaging system, and dose delivery.
Influence of different inhomogeneities on the geometric distortion in stereotactic magnetic resonance imaging P2-58 Josef, Novotny Jr. (1); Josef, Vymazal (2); Pavel, Chuda (3); Dusan, Urgosik (4); Josef, Novotny (5); Roman, Liscak (6) (1) Na Homolce Hospital - Medical physics; (2) Na Homolce Hospital - Stereotactic and radiation neuro- surgery; (3) Na Homolce Hospital - Medical physics; (4) Na Homolce Hospital - Stereotactic and radiation neu- rosurgery; (5) Na Homolce Hospital - Medical physics; (6) Na Homolce Hospital - Stereotactic and radiation neurosurgery Prague, Czech Republic Aim of this study was to evaluate influence of different inhomogeneities on the geometric image distortion in the stereotactic brain magnetic resonance imaging. Cylindrical perspex phantom secured to the base of the Leksell stereotactic frame with special insert consisting of glass solid rods organised in a regular grid was used for the assessment of stereotactic MRI geometric accu- racy. Following inhomogeneities were studied as potential source of MRI stereotactic image geo- metric distortion: air, fat, bone, contrast agent, silver surgical clip, Yasargil surgical clip, ventricu- lar shunt and five different dental materials. The phantom was sequentially stereotactically inves- tigated according to normal imaging procedures done for patients. The images were transferred into the treatment planning system and deviations between stereotactic coordinates based on MRI and real geometrical rod positions were evaluated for each study and further investigated as a function of presented inhomogeneity. Impact of inhomogeneities was studied in two ways: 1) entire stereotactic image geometric distortion (shift in fiducials) and 2) stereotactic image geomet- ric distortion in a volume of the immediate vicinity of the inhomogeneity location. Introduced inhomogeneities caused no additional distortion on the entire stereotactic MRI image and results for these measurements reflected results performed with the phantom with no inhomogeneity (mean image distortion 0.2 mm). The influence on stereotactic image geometric distortion in a volume of the immediate vicinity of the inhomogeneity location was observed only for Yasargil clip and ventricular shunt. The image distortion was observed within about 15 mm distance from the inhomogeneity location in this case. No other studied inhomogeneities showed significant effect on the image distortion. 277 Poster Abstracts
Repositioning accuracy - evolution of a fractioned stereotactic system for the head and neck region P2-59 John, Way (1); Margaret, Schneider (2); Robert Ian, Smee (2); Lyn, Emanuel (2); Karl, Chan (1) (1) Prince of Wales Hospital - Physics Department of Radiation Oncology; (2) University of New South Wales - Prince of Wales Hospital - Department of Radiation Oncology Shatin, Hong Kong INTRODUCTION: Over three years more than twenty patients with head and neck lesions were treated with a stereotactic IMRT technique. Accuracy and reproducibility in the set-up are para- mount. Analysis of the standard deviation of depth probe measurements was done during the evolution of the methods used to immobilise these patients. METHODS: All patients were set-up using the HNL system [Radionics]. Initially the default Support frame assembly system was used. Some patients were uncomfortable with this system, so an alternative was devised. The Med-Tec Uni-frame system was used with the mask base supplied by Radionics. After a trial with standard masks was done, thicker IMRT masks sometimes in combination with a mouthpiece (Precise Bite) were incorporated along with improved posterior support i.e. Accuform cushions or vac-bags. Changes to approaches used to immobilise patients warranted analysis. Standard deviation of depth probe measurements were calculated and displayed in graph form. RESULTS: By analysis of the standard deviation of depth probe measurements, changes to our methods of immobilisation resulted in more accurate repositioning. Results will be presented and discussed. This poster will cover some of limitations encountered with repositioning accuracy and the methods used to over- come these limitations. CONCLUSION: Radiation Therapists should strive to improve techniques especially where known limitations exist. Many past papers discuss these limitations. A combina- tion of methods is usually necessary due to the individual nature of each patient’s treatment.
Applications of polymer gel dosimetry in stereotactic radiosurgery P2-60 Panagiotis, Papagiannis (1); Pantelis, Karaiskos (2); Loukas, Sakelliou (1); Panagiotis, Sandilos (2); Michael, Torrens (3) (1) University of Athens - Physics; (2) Hygeia Hospital - Medical Physics; (3) Hygeia Hospital - Gamma Knife Neurosurgery Department Athens, Greece The advantages of the polymer gel – MRI method and particularly its ability to measure with high spatial resolution 3D dose distributions in a water equivalent material, make it ideal for SRS appli- cations. This work discusses the feasibility of adapting the method for tasks ranging from accept- ance testing to treatment plan verification and the calculation of correction factors in dosimetry using conventional systems. Different polymer gel filled vials were accommodated in a in a cus- tom made head phantom and irradiated on a model 4C Leksell gamma knife® unit according to plans generated by the GammaPlan® software. These plans included single shot delivery at the unit center point (UCP) with each of the four collimators, a plan with multiple, different collima- tor shots resembling a highly conformal, single target treatment as well as a plan resembling the treatment of four brain metastases with four 8 mm collimator shots using different prescription isodose lines and different prescription doses. Measurements were compared to corresponding GammaPlan® calculations in the form of relative dose profiles, planar distributions as well as 3D plan evaluation criteria including the target volume DVH, target coverage and conformity indices. 278 Poster Abstracts
The comparison yielded agreement within experimental uncertainties which are also discussed. Relative dose distributions measured for the 4 mm and 8 mm collimators were averaged for grad- ually expanding cubic volumes centred at the UCP. This allowed for the calculation of appropri- ate volume averaging correction factors of conventional detectors used for output factor determi- nation of the available collimators. Preliminary results support the accuracy of gamma knife poly- mer gel dosimetry using two echo TSE MR sequences which achieve a 60-fold reduction in scan time relative to commonly used multi-echo CPMG sequences. Thus, results of this study combined with the availability of MR scanners in SRS departments support the introduction of the gel dosimetry method in the clinical setting.
Radiosurgery for vertebral angioma. Steretactic body frame P2-61 Luis, Larrea (1); E, Lopez (1); J, Bea (1); M.C., Banos (1) (1) Hospital NISA Virgen del Consuelo - Oncologia Radioterapica Valencia, Spain SBF Setup protocol Objectives: -High target doses -Treatment biologically aggressive -Accurate localization -Better inmovilisation -Better reproducibility -High levels of geometrical accuracy in dose deliver CTV nearby or inside critical organs -Hypofractionated irradiation -Better biological response Treatment requirements: -Immovilitation -Reproducibility -3D coordinates system -3D planning sistem -Conformal beam delivery SBF characteristics Box -wood -Wooded bed (materi- al-rigid) -56*35*120 cm Thickness: very low attenuation Fiducials for CT Easy reproducibility (sta- tistical margin) Immovilisation devices -Diaphragmatic compressor -Vacuum pillow Marks for reposition -External and chest marks -Knee mark SBF Setup protocol Before each CT acquisition session: - Test of geometric and dosimetric parameters (isocenter scales and coordinate system, laser accuracy, CT numbers (HU) (Fig shows: Accuracy and reproducibility of Body Frame align- ment in CT unit, phantom repositioning in CT unit and also in Body Frame. Äz in CT unit is con- sidered as one-half CT-slice thickness.) Patient CT simulation and deviations may be know, we make: -3 times CT scan in different days in one week -CTV*3 and surrounding tissues -Easy anatomical structures*3 PTV determination: GTV margins are determined as the addition of the incertitude of the following contributions: -Internal moving and breathing. -Repositioning of patient inside of BF -Repositioning of BF in the table unit -Incertainty evaluated from LINAC geo- metric parameters Incertainties are evaluated for each patient. GTV position and volume incert- tainties are considered. Breathing, patient repositioning and Body Frame alignment are also stud- ied. Treayement steps: 3D previous dosimetric planning (6 to 8 coplanar or non coplanar beams) On site verification of beams clearance Definitive 3D dosimetric calculation: - DVH in order to evaluate dose in CTV, PTV and risk structures, focusing in Y axis in order to stimate maximal spinal dose. - Exported DRR to i-view to estimate accuracy of isocenter Quality assurrance Periodic LINAC checks and specific test of geometrical and dosimetric parameters previous each treatment ses- sion Patient CT virtual simulation and deviations 3D planning On site verification for beams clear- ance Treatment delivery Find individual margins for PTV Standard beams DVH for tumour, PTV and critical organs Treatement protocol Spine-vertebra 12 Gy single dose SBF Clinical Experience Hospital NISA Virgen del Consuelo. Valencia 5 patientes all with pain remision.
279 Poster Abstracts
Dosimetric effect of intra-fraction motion during spinal radiosurgery P2-62 Martin, J Murphy (1); Cihat, Ozhasoglu (2); Warren, Kilby (3); Derek, Olender (3); (1) Virginia Commonwealth University, Richmond VA; (2) University of Pittsburgh PA; (3) Accuray Incorporated, Sunnyvale CA Richmond, USA PURPOSE: Intra-fraction organ motion causes uncertainty in the delivery of all external beam radi- ation treatments. Radiosurgery has traditionally minimized motion with rigid fixation devices but skeletally-fixated stereotactic frames developed for spinal radiosurgery have not been widely used. Instead the patient is usually restrained using combinations of head mask or frame, cervi- cal spine collar, and vacuum-formed body cast, depending on the target location. These devices allow for potentially significant intra-fraction movement, which introduces to radiosurgery the issue of planning with a motion margin. In image-guided robotic radiosurgery the beam alignment is adjusted repeatedly during treat- ment to minimize the effect of intra-fraction movement. However, there is a residual uncertainty from target motion occurring between corrections. This study has evaluated observed patterns of movement during spine radiosurgery and used these data to assess the dosimetric impact of motion on treatment delivery both with and without periodic motion correction. METHOD: The intra-fraction imaging records of 35+ image-guided spinal radiosurgery treat- ments were reviewed. The distributions of position changes were calculated for all six translation- al and rotational degrees of freedom. Statistical analysis was used to compare the offset distri- butions along each axis, and also the impact of intra-fraction motion correction. Records were evaluated individually to determine the frequency of systematic offsets among the population (defined as a mean translational offset ≥ ±1 mm in at least one axis). Sample treatment plans were recalculated with each group of beams moved relative to the patient by an amount sam- pled from the observed offset distributions, both with and without motion correction. The dosi- metric effects of random, and combined random and systematic offsets, were evaluated. The resulting treatment plans were compared in terms of target volume and spinal cord DVHs. RESULTS: The population offset data shows intra-fraction motion in all axes of translation and rotation. The most significant translational motion was left-right and the most significant rotation was about the superior-inferior axis. The effect of motion correction was to significantly (p<0.01) reduce the observed offsets for all six degrees of freedom. The mean radial translation was reduced by a factor of approximately 2. Systematic offsets were detected in approximately 20% of cases without motion correction, reducing to zero when motion correction was applied. The treatment plan results show that the primary effect of uncorrected random intra-fraction motion is to reduce coverage of the target volume by the prescription isodose. This effect was significant- ly reduced when motion correction was applied. Uncorrected systematic motion was shown to also potentially increase the dose delivered to the spinal cord. The magnitude of these effects depends upon the treatment geometry and the relative direction of motion. CONCLUSIONS: Intra-fraction motion correction removes systematic targeting offsets and reduces random offsets. Therefore, assuming equivalent patient immobilization and pre-treatment align- ment, image-guided robotic spinal radiosurgery can improve upon the targeting accuracy achiev- able with other techniques that do not correct for intra-fraction motion. The treatment plan results demonstrate that this increased accuracy improves target volume coverage in all cases and 280 Poster Abstracts
reduces risk of spinal cord overdose in some cases. This study suggests that motion correction can reduce the required safety margin by approximately a factor of 3.
Implementation of helical tomotherapy for spinal radiosurgery P2-63 John, Fiveash (1); Richard, Popple (2); Jennifer, De Los Santos (2); James, Markert (3); Barton L., Guthrie (4); Chris, Dobelbower (2) (1) University of Alabama at Birmingham - Radiation Oncology; (2) University of Alabama at Birmingham - Radiation Oncology; (3) University of Alabama at Birmingham - Department of Neurosurgery Birmingham, USA Purpose: To evaluate helical tomotherapy for single fraction spinal radiotherapy (radiosurgery). Materials and Methods: Treatment plans from four clinical cases of primary or metastatic paraspinal tumors were generated utilizing two different inverse treatment planning and delivery systems: Eclipse/Helios with Varian 120-MLC (Varian Medical Systems, dMLC) and Tomotherapy Hi-Art2 (TOMO). Varian dMLC plans were developed using a standard, clinically proven technique comprised of seven posterior axial beams spaced 20 degrees apart. Tomotherapy Hi-Art2 helical tomotherapy plans were generated utilizing a 1 cm beam width. The plans were normalized such that the prescription point received the same dose as the clinical plans. Optimization planning goals were maximal spinal cord sparing in the high dose region and maximum dose less than 140%. Plans that were not acceptable due to another organ at risk were rejected. The feasibility of megavoltage CT imaging for determination of intrafraction motion was studied in a clinical tomotherapy patient. Results: Dose heterogeneity was slightly better in the TOMO plans with a mean maximum PTV dose of 133.6% vs 139.9% with dMLC. TOMO also produced plans with a lower volume of spinal cord receiving the higher doses of RT. The average dMLC plan produced a 33% higher dose to 0.5 cc of spinal cord than TOMO. Pre and post treatment CT scans were fused without difficulty on the clinical TOMO console to determine intrafraction motion including translation and rotation. Conclusions: The Tomotherapy Hi-Art system contains all the essential elements for spinal radiosurgery: dose conformality, accurate image guidance for initial target localization, and the ability to determine intrafraction motion, although not in real-time. Our pre- clinical studies suggest that there may be a dosimetric advantage for helical tomotherapy over other MLC delivery systems in some selected cases depending upon how plan quality is meas- ured. An ongoing clinical trial will determine intrafraction motion and then study the efficacy and toxicity of single fraction radiosurgery in patients with paraspinal tumors.
Spinal radiosurgery: the consequences of “segmental image fusion technique” and its clinical experiences P2-64 Moon-Jun, Sohn (1); Dong-Joon, Lee (1); Yoon-Joon, Hwang (2); Sang-Ryong, Jeon (3); Ho-Yeon, Lee (4); Sang-Ho, Lee (5); C. Jin, Whang (1) (1) Inje University - Ilsan Paik Hospital - Department of Neurosurgery; (2) Inje University Ilsan Paik Hospital - Department of Neuroradiology; (3) Asan Medical Center, College of Medicine, University of Ulsan - Department of Neurosurgery; (4) Wooridul General Hospital - Department of Neurosurgery Goyang, Korea To investigate the optimum coordination method of image discrepancy affected by changes in body position for image fusion and clinical results in spinal radiosurgery. Twenty patients with spinal tumors underwent image-guided spinal stereotactic radiosurgery and their clinical results 281 Poster Abstracts
were evaluated. To optimize the coordination of different diagnostic image sets, the segmental image fusion method was used. Thin multi- sliced MR images were obtained from the segments of interest in a perpendicular angle without spacing. Then, multiple segmented MR images were correlated onto the CT images integrated with stereotactic localizer by defining the objects as anatomical landmarks. The consequence of image fusion was evaluated by using volumetric measurements of targets on each image modality and by analyzing optimal dose planning and proper image fusion. : Differences of gross tumor volume (GTV) between CT and MR based plan- ning compared with GTV of CT-MR image fusion were 30.5 + 4.8 % and 14.5 + 3.3 %, respec- tively. Measured value of GTV in CT-MRI image fusion was 14.06 cm3 and GTV of CT versus MR based planning was 11.64 cm3 vs. 11.72 cm3, respectively. Positional discrepancy of two image sets was minimized with this segmental image fusion method. Mean tumor volume and pre- scribed dose of benign and metastatic spinal tumors were 3.54 cm3 vs. 24.47 cm3 and 17.6Gy vs. 26.4 Gy at 80% isodose line in 1.6 vs. 2.9 fractions, respectively. The pain was remarkably reduced within two weeks. Most of the tumors were stable or reduced in their volume during fol- low-up period. : Image fusion was successfully performed using segmental fusion technique. Segmental image fusion method provides better identification of spinal structures and significant improvement on precise radiosurgical treatment planning.
Non-invasive radiological evaluation of superior cerebellar artery after gamma knife radiosurgery for idiopathic trigeminal neuralgia: preliminary results of a cohort study P2-65 José, Lorenzoni (1); Philippe, David (2); Nicolas, Massager (3); Daniel, Devriendt (4); Françoise, Desmedt (1); Paul, Van Houtte (4); Jacques, Brotchi (3); Marc, Levivier (1) (1) Hôpital Erasme - Centre Gamme Knife; (2) Hôpital Erasme - Neuroradiologie; (3) Hôpital Erasme - Neurochirurgie; (4) Institut J. Bordet - Radiothérapie Brussels, Belgium Objective: To study non-invasive radiological changes on Superior Cerebellar Artery (SCA) after gamma knife radiosurgery on patients suffering Idiopathic trigeminal Neuralgia (ITN) using a dis- tal targeting treatment protocol. Material and Methods: A measure of the maximal dose received by SCA was performed studying the treatment planning for all patients treated radiosurgically for ITN. In those patients with a dose received by the SCA was 10 Gy or more, a prospective cohort study was designed. This study considers high resolution MRI, including T1, T1 Gad, T2 , Proton density, and 3D TONE based angio MRI sequences. The end points were the existence of any infarction in the SCA territory or any obstruction or stenosis of the SCA. Results: 16 patients have been included in this study. Mean dose received by the SCA was 57.5 Gy. (15 – 87 Gy.) And the mean radiological follow up was 25 months, (12 – 42 months). Until now, no patient in the study have presented radiological changes, neither in the permeability of the SCA, nor in the cerebellar parenchyma. Conclusions: SCA can receive a high dose of radiation after a radiosurgical treatment of ITN, and although this study hasn’t shown any vascular change at this level, it could be prudent to keep in mind a potential complication and to consider, perhaps, the SCA as one structure at risk.
282 Poster Abstracts
Stereotactic radiosurgery for trigeminal neuralgia using a non-dedicated linear accelerator P2-66 Salvador, Somaza (1) (1) La Floresta Medical Institute - Stereotactic Radiosurgery Unit Miami, USA Introduction: The authors evaluate the efficacy and safety associated with the use of Stereotactic Radiosurgery for trigeminal neuralgia (TN) with a non-dedicated linear accelerator Methods: Between March 2003 and March 2005, 10 patients were treated with a non-dedicated linear accelerator for trigeminal neuralgia. The median age was 55.1 y.o. (range 48-73 years). All patients had essential TN. Five patients had undergone previous surgical procedures. In one of them, five radiofrequency procedures were performed. Radiation doses were 80 Gy in 4 cases and 90 Gy in the other six patients. A 4-mm collimator was used in all treatments. A isodoses curve of 50% was used focusing the treatment on the entry zone. Results: Initial results showed pain relief in all cases. Pain relief was experienced at an average of 1.14 months (range 15 days to 4 months) after the procedure. The mean follow-up period was 14 months (range 4 to 24 months). At the last follow-up, 9 patients had sustained significant pain relief. Six patients were pain free without medication and three patients had a significant reduction in pain with low doses of medication. One patient had persistent pain. This patient had a concurrent facial hemis- pasm. No patient experienced new numbness post-radiosurgery or other complications. Conclusions: Stereotactic Radiosuregery using a non-dedicated linear accelerator is a safe, effec- tive and precise treatment for TN
The complication rates after gamma knife radiosurgery for facial pain are predicted by pre-treatment Burchiel classification pain type: results from 256 gamma knife radiosurgery procedures P2-67 Thomas, Ellis (1); Volker W., Stieber (2); Stephen, Tatter (1); Alan, deGuzman (2); Kenneth, Ekstrand (2); Michael, Munley (2); Daniel, Bourland (2); Kevin, McMullen (2); William, Huang (2); Lovato, James (3); Christopher, Balamucki (4); Charles, Branch (1); Edward G., Shaw (2) (1) Wake Forest University School of Medicine - Department of Neurosurgery; (2) Wake Forest University School of Medicine - Department of Radiation Oncology; (3) Wake Forest University School of Medicine - Public Health Sciences; (4) Wake Forest University - School of Medicine Winston Salem, USA Introduction: Facial pain is a spectrum of conditions of varying clinical behavior. Burchiel has sug- gested a pain classification scheme (BPC) for seven different types of facial pain. We analyzed the complication rates of 256 gamma knife radiosurgery procedures for facial pain based on their pre- treatment BPC. Clinical Material and Methods: Between 09/99 and 03/04, 326 GKRS procedures for patients with facial pain were performed. Typically the 50% isodose line was placed tangen- tial to the brainstem, with the shot isocenter targeted at the proximal trigeminal nerve root. The radiation dose was prescribed at the 100% isodose line. Patients self reported pain control data via a detailed questionnaire. Results: 6/7 types of BPC were represented (no patients had deaf- ferentation pain). 240 patients were treated with one 4 mm isocenter. 49%, 20%, and 25%, received 90 Gy, 85 Gy, or 80 Gy, respectively. Dose was prescribed at the 100 % isodose line. Patients with typical TN aka Type 1 experienced the lowest incidence of complications: 38% 283 Poster Abstracts
described facial numbness, 20% described tingling or prickling, and 4% described a burning sen- sation after treatment. Among patients with TN Type 2, 41%, 20%, and 19%, experienced the above post-treatment symptoms, respectively. Among patients with somatoform pain disorder, 35%, 40%, and 10%, experienced the above post-treatment symptoms, respectively. Among patients with multiple sclerosis, 38%, 25%, and 13%, experienced the above post-treatment symptoms, respectively. Among patients with neuropathic pain, 38%, 13%, and 24%, experi- enced the above post-treatment symptoms, respectively. The worst outcome was seen with pos- therpetic neuralgia patients, of whom 67%, 17% and 50%, experienced the above post-treat- ment symptoms, respectively. Conclusion: This study demonstrates that the pre-treatment BPC predicts for post-GKRS complications. This allows the clinician to assess the risk-benefit ratio for each sub-classification of facial pain.
The success of gamma knife radiosurgery for facial pain varies by pre-treatment Burchiel classification pain type: results from 256 gamma knife radiosurgery procedures for trigeminal neuralgia P2-68 Volker W., Stieber (1); Thomas, Ellis (2); Alan, deGuzman (1); Edward G., Shaw (1); Charles, Branch (2); Daniel, Bourland (1); Kevin, McMullen (1); Christopher, Balamucki (3); Michael, Munley (1); Kenneth, Ekstrand (1); Lovato, James (4); William, Huang (1); Stephen, Tatter (2) (1) Wake Forest University School of Medicine - Department of Radiation Oncology; (2) Wake Forest University School of Medicine - Department of Neurosurgery; (3) Wake Forest University - School of Medicine; (4) Wake Forest University School of Medicine - Public Health Sciences Winston Salem, USA Introduction: Facial pain is a spectrum of conditions of varying clinical behavior. Burchiel has sug- gested a pain classification scheme (BPC) for seven different types of facial pain. We analyzed the outcomes of 256 gamma knife radiosurgery procedures for facial pain based on their pretreat- ment BPC. Clinical Material and Methods: Between 09/99 and 03/04, 326 GKRS procedures for patients with facial pain were performed. Typically the 50% isodose line was placed tangential to the brainstem, with the shot isocenter targeted at the proximal trigeminal nerve root. The radi- ation dose was prescribed at the 100% isodose line. Patients self reported pain control data via a detailed questionnaire. Results: 6/7 types of BPC were represented (no patients had trigeminal deafferentation pain). 240 patients were treated with one 4 mm isocenter. 49 %, 20 %, and 25%, received 90 Gy, 85 Gy, or 80 Gy, respectively. Dose was prescribed at the 100 % isodose line. Independently of prescription dose, a significant association between the type of facial pain and the pain control rate after GKRS was observed in the study (Pearson; p<0.001). Patients with typical TN aka Type 1 (n=172) experienced the best results from GKRS: 90 % had pain relief, 80 % reported improved quality of life, median time to improvement was 4 weeks, and pain recurred in only 19 % with a median pain-free interval of 1.25 years. The worst outcome was seen with postherpetic neuralgia (n=6), with no patients experiencing pain relief or an improvement in their quality of life. Conclusion: This study demonstrates that Burchiel classification of the facial pain affects facial pain outcome post-GKRS, allowing for proper patient selection, especially of “atypi- cal” facial pain types.
284 Sponsored Sessions Abstracts
LUNCH SEMINAR BRAINLAB 12/09/05
NOVALIS FOR FUNCTIONAL NEUROSURGERY Room Nation Chairman: Antonio AF, De Salles
Novalis for functional neurosurgery Antonio AF De Salles, MD, PhD; Alessandra Gorgulho, MD; Paul Medin, PhD; Nzhyde Agazarian, PhD; Timothy Solberg, Ph.D.; Michael Selch, MD UCLA - Departments of Neurosurgery and Radiation Oncology, Los Angeles, USA INTRODUCTION: Functional changes in the central nervous system (CNS) are possible via destruc- tion of pathways, nuclei or modification of cellular function. Precise, fast and homogeneous dose delivery becomes important in modern Functional Radiosurgery. METHODS: From December 1997 to April 2005 several approaches to Functional Radiosurgery were tested using the Novalis. Animal experimentation conducted for Parkinson’s disease, Epilepsy and Chronic Pain supported the clinical use of Novalis in Trigeminal Neuralgia (176 patients), Cluster Headache (4 patients), Essential Tremor (3 patients), Chronic Pain (3 patients) and Epilepsy (5 patients). Homogeneous plans using the shaped-beam technique were devel- oped to completely envelope mesial temporal structures related to Temporal Lobe Epilepsy. RESULTS: Modification of cell function was observed electrophysiologically and histologically in animal models for epilepsy and Parkinson’s disease. Obliteration of pathways and nuclei were observed when targeting the spinal dorsal root ganglion, the root entry zone of the trigeminal nerve, the thalamus, and the subthalamic nucleus. Functional changes related to pain improve- ment were observed in patients with cluster headache by observing symptomatic relief. Homogeneous plans to the level of 10% from the center to the periphery were observed in plan- ning for mesial temporal lobe structure modification. CONCLUSIONS:This experience shows that the Novalis technology is precise and capable of deliv- ering high doses (150Gy) for tissue ablation, as well as low doses (15 Gy) tightly, conformally, and homogeneously for functional modification without radiation necrosis.
LUNCH SEMINAR MEDTRONIC 14/09/05
THE COMPLEMENTARY ROLE OF INTRA OPERATIVE MRI AND RADIOSURGERY Room Nation Chairman: Jacques, Brotchi
ULB Erasme experience of treating patients with PoleStar and gamma knife Prof. J. Brotchi Dept. of Neurosurgery, Erasme Hospital, Université Libre de Bruxelles, Brussels, Belgium Image-guided neurosurgery has gained broad acceptance as this technology has defined new standards for minimally invasive procedures. However, accuracy issues still hamper success for 285 Sponsored Sessions Abstracts
complex brain tumor resection interventions. The main confounding factor is due to anatomical deformations during the course of the surgery resulting from CSF leakage and retraction and abla- tion of tissue. As part of a phase 1 study on the integration of preoperative images used for navigation with iMRI controls, we have coupled the current PoleStar hardware with the addition of a StealthStation (Medtronic SNT, Boulder, Co) computer. The current PoleStar software interface is used for all scanning functions, while the StealthStation application is used to load preoperative images and merge them with the intra-operative images. Since June 2004, we have applied this protocol to 20 patients, aiming at the development of an image processing scheme for robust and accurate registration between the image modalities. These cases demonstrate the benefits of the integration of low field intra-operative imaging system with pre-operative imaging within the context of neuronavigation and its potential role as an adjunct for combined therapy with partial tumor removal followed by radiosurgery.
Complementary use of intra operative MRI technique and radiosurgery Dr. M. Schulder New Jersey Medical School, Department of Neurosurgery, Newark NJ, USA Introduction. Surgery and stereotactic radiosurgery (SRS) are often presented as mutually exclu- sive options for patients with intracranial tumors. However, many patients may be best served by a planned strategy of subtotal resection followed by planned adjuvant SRS. Intraoperative MRI (iMRI) may be used to ensure that in such cases the surgical goals have been reached – i.e. that the residual lesion is small enough for safe and effective SRS. Methods. In 20 twenty patients, iMRI-guided resection and adjuvant SRS was planned. Diagnoses included meningioma in 11 patients (9 skull base, 2 parasagittal), pituitary adenoma in 6, schwannoma in 2, and craniopharyngioma in 1. IMRI was acquired with the PoleStar sys- tem (Odin/Medtronic Surgical Navigation Systems, Louisville CO, USA). Images were obtained before surgery and when the surgical goals were though to be achieved. Surgical planning was done with the integrated infrared surgical navigation tool. Results. A complete resection was done in 3 patients. IMRI led to additional resection in 6 patients, while in another 7 unnecessary dissection was avoided when images showed that the surgical goals had been reached. In 13 patients, a suitable target for SRS remained after surgery. Five patients underwent SRS while 8 chose observation and followup imaging. Progression was seen in only one patient who proved to have a malignant meningioma. Stereotactic radiation therapy was used to treat 2 patients and 3D conformal RT for the remaining 2 patients. Conclusions. Images acquired with iMRI had an impact on 13/20 patients in whom the preoper- ative surgical plan was subtotal resection plus adjuvant SRS. In such patients, a complete surgi- cal resection remains ideal and should be pursued if safely possible. The appropriate timing of SRS after subtotal resection is still uncertain, and observation remains an option for patients with benign tumors.
286 Sponsors and Exhibitors Acknowledgements
The scientific committee, the local organising committee, the officers and the board members of the ISRS 2005 congress wish to kindly acknowledge the following companies for their confidence, their precious support and their active collaboration (listed by alphabetical order). ISRS 2005 Major Sponsors and Exhibitors BrainLAB Elekta Sponsors and Exhibitors Accuray American Radiosurgery Dixi medical / BioScan IBA Particle Therapy Medtronic 3D Line Medical Systems s.r.l. Exhibitors Alcis & Neuropace Carl Zeiss Surgical GmBH Foundation Against Cancer, Belgium inomed Medizintechnik GmBH Medical Intelligence Nomos Radiation Oncology - A Division of North American Scientific Orfit Industries NV Philips PTGR-GmbH Radionics, a Division of Tyco Healthcare Belgium N.V. Siemens TomoTherapy Incorporated Varian Medical Systems Contributors Codali-Guerbet GE Healthcare Pfizer S. Karger AG NV Schering SA Academic Sponsors Belgacom Bruxelles Capitale Communauté Française FNRS
Additional thanks from the Local Organization Committee to the Magritte Foundation and Brussels International.