DOCSLIB.ORG

13 Definition of Target Volume and Organs at Risk. Biological Target

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
13 Definition of Target Volume and Organs at Risk. Biological Target Defi nition of Target Volume and Organs at Risk. Biological Target Volume 167 13 Defi nition of Target Volume and Organs at Risk. Biological Target Volume Anca-Ligia Grosu, Lisa D. Sprague, and Michael Molls CONTENTS into consideration: the results of radiological and clinical investigations; tumour staging; surgical and 13.1 Introduction 167 histo-pathological reports; other additional treat- 13.2 Defi nition of Target Volume 168 13.2.1 Gross Target Volume 168 ments such as chemotherapy; immune therapy; the 13.2.2 Clinical Target Volume 168 patient’s history; the anatomy of the region to be irra- 13.2.3 Internal Target Volume 169 diated; and the acceptance of the patient concerning 13.2.4 Planning Target Volume 169 radiation treatment. But also the technique used for 13.2.5 Treated Volume 169 irradiation, including the patient’s positioning and 13.2.6 Irradiated Volume 169 13.3 Defi nition of Organs at Risk 169 fi xation, are of major importance. As a consequence, 13.4 New Concepts in Target Volume Defi nition: the complexity of the process when defi ning the tar- Biological Target Volume 170 get volume requires sound clinical judgement and 13.4.1 Where is the Tumour Located and Where Are the knowledge from the radiation oncologist. (Macroscopic) Tumour Margins? 170 Three-dimensional conformal treatment plan- 13.4.1.1 Lung Cancer 170 13.4.1.2 Head and Neck Cancer 172 ning in radiation oncology is based on radiological 13.4.1.3 Prostate Cancer 172 imaging, CT and MRI. These investigative techniques 13.4.1.4 Brain Gliomas 172 show the anatomical structures with a high accuracy. 13.4.2 Which Relevant Biological Properties of the Both CT and MRI image tumour tissue by taking ad- Tumour Could Represent an Appropriate Biological vantage of the differences in tissue density (or signal Target for Radiation Therapy? 173 13.4.3 What is the Biological Tumour Response to intensity in MRI), contrast enhancement or the abil- Therapy? 174 ity to accumulate water (oedema). But these signals 13.5 Conclusion 175 are not specifi c to tumour tissue alone. They can also References 176 be observed after a trauma or surgery, or infl amma- tory or vascular disease. This can hamper diagnosis and delineation of a tumour, and represents the most important limitation of these traditional radiological investigation techniques. 13.1 Biological imaging visualises biological pathways. Introduction Positron emission tomography (PET) and single photon computed emission tomography (SPECT) are The defi nition of the target volume and of critical characterised by visualising a tumour using radioac- structures is a crucial and complex process in three- tive tracers. These tracers have a higher affi nity for dimensional conformal radiation therapy. In a plan- tumorous tissue in comparison with normal tissue. ning system, based either on computed topography Magnetic resonance spectroscopy (MRS) imaging (CT) or magnetic resonance imaging (MRI), the ra- provides information on the biological activity of a diation oncologist is required to outline the target tumour based on the levels of cellular metabolites; volume to be irradiated, and the organs of risk to therefore, the information obtained from different be spared, because of possible side effects. In this imaging modalities is in general complementary by process, a multitude of information has to be taken nature. This chapter discusses the standard concepts de- fi ned in the ICRU report 50 (ICRU 50 1993) and the A.-L. Grosu, MD; L.D. Sprague, PhD; M. Molls, MD Department of Radiation Oncology, Klinikum rechts der Isar, ICRU report 62 (ICRU 62 1999). Additionally, we dis- Technical University Munich, Ismaningerstrasse 22, 81675 cuss the impact of biological investigations in target Munich, Germany volume delineation. 168 A.-L. Grosu et al. 13.2 sue and is surrounded by perifocal oedema. Based on Defi nition of Target Volume these radiological characteristics, the radiation oncol- ogist has to outline on each section the areas of gross Both ICRU report 50 from 1993 and ICRU report tumour tissue. The demarcation of the GTV needs 62 from 1999 standardised the nomenclature used profound radiological knowledge. The technique used for three-dimensional conformal treatment planning for the CT or MRI investigation and the window and and thus gave the community of radiation oncolo- level settings have to be appropriate for the anatomical gists a consistent language and guidelines for image- region. The volume of the gross tumour tissue visu- based target volume delineation. The following terms alised on CT or MRI should correspond to the volume were defi ned: gross tumour volume (GTV); the clini- of the actual macroscopic tumour extension. cal target volume (CTV); the internal target volume A major problem when delineating residual tu- (ITV); the planning target volume (PTV); the treated mour tissue in surgically treated patients is the rec- volume; and the irradiated volume (Fig. 13.1). ognition and differentiation of changes caused by surgery itself. But also contrast enhancement, oe- dema and hyper- or hypodensity (intensity) of the tissue can cause diffi culties, ultimately resulting in inaccurate GTV delineation. Sometimes it is extremely diffi cult or even impos- sible to delineate the gross tumour mass when using conventional radiological investigation techniques such as CT and MRI. An example is the visualisation of prostate cancer with current imaging methods (CT, MRI, sonography). In this case, for three-dimen- sional treatment planning, the radiation oncologist delineates the prostate encompassing the GTV and the clinical target volume (CTV). Fig. 13.1. Concepts used in target volume defi nition for radia- tion treatment. An accurate delineation of tumour tissue should focus the irradiation dose on the GTV and spare sur- rounding normal tissue. New investigative techniques, 13.2.1 such as positron emission tomography PET, SPECT Gross Target Volume and MRS, visualise tumour tissue with a higher speci- fi city. It seems likely that these techniques will help The gross tumour volume (GTV) is the macroscopic in the future to delineate tumour tissue with higher (gross) extent of the tumour as determined by radio- precision. The possibility to integrate these “biologi- logical and clinical investigations (palpation, inspec- cal” investigative techniques in GTV defi nition is dis- tion). The GTV-primary (GTV-P) defi nes the area of cussed in the section “Biological Target Volume”. the primary tumour and GTV-nodal (GTV-N) the macroscopically involved lymph nodes. The GTV is obtained by summarising the area outlined by the ra- 13.2.2 diation oncologist in each section, multiplied by the Clinical Target Volume thickness of each section. The extension of the GTV is of major importance for the treatment strategy: The GTV, together with the surrounding microscopic in many cases the gross tumour tissue is irradiated tumour infi ltration, constitutes the primary clinical with higher doses, as it is encompassed within the target volume CTV (CTV-P). It is important to men- boost volume. The GTV can represent the total vol- tion that the defi nition of the CTV-P also includes the ume of the primary tumour, the macroscopic residual tumour bed, which has to be irradiated after a complete tumour tissue after partial tumour resection or the macroscopic tumour resection, in both R0 (complete region of recurrence after either surgical, radiation microscopic resection) and R1 (microscopic residual or chemotherapeutic treatment. tumour on the margin of the tumour bed) situation. The delineation of the GTV is usually based on data Moreover, for CTV-P defi nition, anatomical tumour obtained from CT and MRI. In general, tumour tissue characteristics have to be considered, such as the likeli- shows contrast enhancement, has a different density hood of perineural and perivascular extension or tu- (CT) or intensity (MRI) compared with the normal tis- mour spread along anatomical borders. As the margins Defi nition of Target Volume and Organs at Risk. Biological Target Volume 169 between CTV and GTV are not homogenous, they have reduced and the dose applied to the GTV/CTV can to be adjusted to the probable microscopic tumour be escalated. spread. The CTV-nodal (CTV-N) defi nes the assumed microscopic lymphatic tumour spread, which has also to be included in the radiation treatment planning. 13.2.5 Treated Volume 13.2.3 The treated volume is the volume of tumour and Internal Target Volume surrounding normal tissue included in an isodose surface representing the irradiation dose proposed The internal target volume (ITV) is a term intro- for the treatment. As a rule this corresponds to the duced by the ICRU report 62. The ITV encompasses 95% isodose. Ideally, the treated volume should cor- the GTV/CTV plus internal margins to the GTV/CTV, respond to the PTV; however, in many cases the caused by possible physiological movements of or- treated volume exceeds the PTV. The coherence of gans and tumour, due to respiration, pulsation, fi ll- an irradiation plan can be described/illustrated as the ing of the rectum, or variations of tumour size and correlation between PTV and treated volume. shape, etc. It is defi ned in relation to internal ref- erence points, most often rigid bone structures, in an internal patient coordinate system. Observation 13.2.6 of internal margins is diffi cult, in many cases even Irradiated Volume impossible. Examples for reducing internal margins are the fi xation of the rectum with a balloon during The irradiated volume is a volume included in an irradiation of the prostate or body fi xation and ad- isodose surface with a possible biological impact on ministration of oxygen to reduce respiration move- the normal tissue encompassed in this volume; there- ments during stereotactic radiotherapy. fore, the irradiated volume depends on the selected isodose curve and the normal tissue surrounding the tumour.
Load more

Recommended publications
  • Technicolor Graphic Services, Inc SKYLAB I (1/2) SENSITOMETRIC SUMMARY
    TR 73-3 TECHNICAL REPORT NASA CR- -J SKYLAB I (1/2) SENSITOMETRIC SUMMARY Prepared Under Contract NAS 9-11500 Task Order HT-90 N75-16 7 9 5 rASA-CR-141605) SKYL B 1 (1/2) NSITOMETEIC SUMMARY (Technicolor Graphic rvices, Inc.) 75 p HC $4.25 CSCL E nclas G3/3 5 09919 Prepared By Mark S. Weinstein Photoscientist September 1973 NATIONAL AERONAUTICAL AND SPACE ADMINISTRATION LYNDON B. JOHNSON SPACE CENTER PHOTOGRAPHIC TECHNOLOGY DIVISION HOUSTON, TEXAS Technicolor Graphic Services, Inc SKYLAB I (1/2) SENSITOMETRIC SUMMARY This report has been reviewed and is approved. SUBMITTED BY: Ma$ S. Weinstein, Photoscientist APPROVED: /............... &erard E. Sauer, Supervisor Photo Science Office CONCURRENCE: Jo eph E. Nickerson, Operations Manager APPROVED: UJ.J\3 Noel T. Lamar, Technical Monitor CONCURRENCE: j.& R. a nnirnann,Chief Photographic Technology Division -4 CO ,< G"rm~ ,W F= t SKYLAB I (1/2) SENSITOMETRIC SUMMARY TABLE OF CONTENTS SECTION PAGE I Introduction................................. 1 II Skylab I (1/2) Film Radiation Summary...... 2 III Original Flight Film Sensitometry........... 5 A. S190A Experiment......................... 5 B. S190B Experiment...................... 53 C. Mag CI 08...........,................... 59 D. Mag CI 15.............................. 61 E. Mag MT 03.. .............................. 63 F. Mag CX 01.............................. 65 G. Mag CX 02................................ 69 H. Mag CX 03............................... 73 I. Mag CX 04............................. 77 J. Mag CX 05............................. 81 K. Mag CX 06 .............................. 85 L. Mag CX 23............................. 89 M. Mag BV 01............................. 93 N. Mag BV 02 ................................... 95 O. Mag BH 01............................. 97 P. Mag BH 02 ............................. 99 Q. S-056 Experiment....................... 101 R. S-183 Experiment ...................... 105 TABLE OF CONTENTS ...
    [Show full text]
  • Technical Guidelines for Head and Neck Cancer IMRT on Behalf of the Italian Association of Radiation Oncology
    Merlotti et al. Radiation Oncology (2014) 9:264 DOI 10.1186/s13014-014-0264-9 REVIEW Open Access Technical guidelines for head and neck cancer IMRT on behalf of the Italian association of radiation oncology - head and neck working group Anna Merlotti1†, Daniela Alterio2†, Riccardo Vigna-Taglianti3†, Alessandro Muraglia4†, Luciana Lastrucci5†, Roberto Manzo6†, Giuseppina Gambaro7†, Orietta Caspiani8†, Francesco Miccichè9†, Francesco Deodato10†, Stefano Pergolizzi11†, Pierfrancesco Franco12†, Renzo Corvò13†, Elvio G Russi3*† and Giuseppe Sanguineti14† Abstract Performing intensity-modulated radiotherapy (IMRT) on head and neck cancer patients (HNCPs) requires robust training and experience. Thus, in 2011, the Head and Neck Cancer Working Group (HNCWG) of the Italian Association of Radiation Oncology (AIRO) organized a study group with the aim to run a literature review to outline clinical practice recommendations, to suggest technical solutions and to advise target volumes and doses selection for head and neck cancer IMRT. The main purpose was therefore to standardize the technical approach of radiation oncologists in this context. The following paper describes the results of this working group. Volumes, techniques/strategies and dosage were summarized for each head-and-neck site and subsite according to international guidelines or after reaching a consensus in case of weak literature evidence. Introduction Material and methods Performing intensity-modulated radiotherapy (IMRT) The first participants (AM, DA, AM, LL, RM, GG, OC, in head and neck cancer patients (HNCPs) requires FM, FD and RC) were chosen on a voluntary basis training [1] and experience. For example, in the 02–02 among the HNCWG members. The group was coordi- Trans Tasman Radiation Oncology Group (TROG) nated by an expert head and neck radiation oncologist trial, comparing cisplatin (P) and radiotherapy (RT) (RC).
    [Show full text]
  • Gex Doc# 100-259 1.0 Purpose 2.0
    GEX DOC# 100-259 INVESTIGATION OF DOSIMETER MEASUREMENTS GEX Recommended Procedure Eff. Date: 09/21/10 Rev.: D Pg. 1 of 4 NOTICE: This document is version controlled and was produced as a part of the GEX Information Program which requires that all Series 100 documents be reviewed periodically to maintain currency and continuity of information. Appropriate Technical Memorandum are used to provide information detail in support of the Product Data Sheets as well as GEX Recommended Procedures and to provide technical information in support of GEX Marketing documents. 1.0 PURPOSE This procedure describes the GEX methods recommended for use in investigating and evaluating suspected outlier measurements or for investigation of dosimeter measurements that differ from the expected dose, including how to re-measure dosimeters. The methods may also be used to verify a prior result by re-measurement of any dosimeter. NOTE: Dosimeter measurement verification and investigation may be warranted for a variety of reasons and is considered a normal and vital activity associated with a quality dosimetry program. Keep in mind that any change to a measurement and its associated dose must be appropriately documented and supported by a strong rationale. A major advantage of using B3 radiochromic film dosimeters is that they are completely stable if properly heat treated after irradiation and can therefore be re-measured as part of an investigation with highly reproducible results. 2.0 MATERIALS 2.1 WINdose Dosimetry System 3.0 FREQUENCY 3.1 As needed. 4.0 PROCEDURE FOR INVESTIGATION 4.1 Obtain a copy of the specific dose report to be investigated along with the dosimeters from that run.
    [Show full text]
  • Hippocampus-Sparing Whole-Brain Radiotherapy: Dosimetric Comparison Between Non-Coplanar and Coplanar Planning
    11 Original Article Page 1 of 11 Hippocampus-sparing whole-brain radiotherapy: dosimetric comparison between non-coplanar and coplanar planning Li-Jhen Chen1, Ming-Hsien Li1,2, Hao-Wen Cheng1,3, Chun-Yuan Kuo1,3, Wei-Lun Sun1, Jo-Ting Tsai1,2 1Department of Radiation Oncology, Shuang Ho Hospital, Taipei Medical University, Taipei, Taiwan; 2Department of Radiology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan; 3School of Biomedical Engineering, College of Biomedical Engineering, Taipei Medical University, Taipei, Taiwan Contributions: (I) Conception and design: LJ Chen, MH Li; (II) Administrative support: JT Tsai; (III) Provision of study material or patients: JT Tsai, MH Li; (IV) Collection and assembly of data: LJ Chen, CY Kuo, HW Cheng, WL Sun; (V) Data analysis and interpretation: LJ Chen, CY Kuo, HW Cheng; (VI) Manuscript writing: All authors; (VII) Final approval of manuscript: All authors. Correspondence to: Jo-Ting Tsai, MD, PhD. Department of Radiation Oncology, Shuang Ho Hospital, Taipei Medical University, No. 291, Zhongzheng Rd., Zhonghe Dist., New Taipei City 235, Taiwan. Email: [email protected]. Background: To compare non-coplanar and coplanar volumetric-modulated arc therapy (VMAT) for hippocampal avoidance during whole-brain radiotherapy (HA-WBRT) using the Elekta Synergy and Pinnacle treatment planning system (TPS) according to the suggested criteria of the radiation therapy oncology group (RTOG) 0933 trial. Methods: Nine patients who underwent WBRT were selected for this retrospective study. The hippocampus was contoured, and the hippocampal avoidance regions were created using a 5-mm volumetric expansion around the hippocampus for each patient. Non-coplanar and coplanar VMAT plans were generated for each patient.
    [Show full text]
  • Portable Transmission Densitometer
    341C Portable Transmission Densitometer A Portable Densitometer Capable Of Measuring Density and Dot Area Applications Densities Greater than 5.00 The 341C can be used to make dot area and density The 341C Portable Transmission Densitometer concentrates measurements quickly and easily.The density function is useful the best features of a tabletop densitometer inside a compact, for evaluating and setting the exposure of any imagesetting portable, and economical hand-held unit. We designed the system, positive or negative. Use it to verify the Dmax of your 341C as a completely self-contained instrument able to take films, ensuring light-blocking film properties when making proofs measurements anywhere you need. or printing plates. A Solid Performer The dot area function is useful for verifying screen tint values from contact films, duplicate films, or originals. It can zero on the The X-Rite 341C includes a calibrated, internal light source. film base, and accurately measure from 0 to 100 percent. It is It meets global standards for geometry of a transmission handy and easy to use in linearizing or calibrating the tone value densitometer, including proper diffusion of the light source, of any imagesetter. enabling true measurement values. Consider pairing the 341C with our popular pressroom The 341C measures density and dot area with extraordinary handhelds, like 500Series or SpectroEye to create unique accuracy — in fact, it’s capable of measuring densities greater capabilities.This combined system has the ability to measure solid than 5.0D.The model 341C includes a calibration reference that and screened areas of your images on both film and paper.
    [Show full text]
  • Dmax) for 6 MV High-Energy Photon Beams Using Different Dosimetric 1School of Physics, Universiti Detectors Sains Malaysia, Penang, Malaysia
    Biohealth Science Bulletin 2010, 2(2), 38 - 42 Radaideh K M et al. 2010 Radaideh K M1, Alzoubi A S2 Factors impacting the dose at maximum depth dose (dmax) for 6 MV high-energy photon beams using different dosimetric 1School of Physics, Universiti detectors Sains Malaysia, Penang, Malaysia. Objectives: Deciding the tumorcidal dose is very important in radiation therapy as it is 2Advanced Medical & Dental limited by skin dose. The aims of this study were to investigate the impacts of using Institute, Universiti Sains physical wedge filter, different source to surface distances (SSD) and field sizes (FS) on the Malaysia, Penang, Malaysia dose at the depth of maximum dose (dmax) using 6 MV high-energy photon beams. Materials and methods: The measurements were made in Solid Water Phantom at (Received July 6th, 2010 Revised August different settings of SSD and FS for 6 MV high-energy photon beams using LiF: Mg; Ti TLD 25th, 2010 Accepted August 25th, 2010 and FC65-G Ionization Chamber. Published online Disember 22nd, 2010.) Results: It was observed that when physical wedge was used at reference settings, the doses at dmax decreased significantly as compared with open fields. Moreover, these Correspondence: Ahmad Saleem Salem doses decreased proportionally with an increase in the wedge angle until 45°, after which Alzoubi the dose increased slightly. The doses at dmax were also inversely related to SSD while it Email: [email protected] had an extrusive relationship with field size. Conclusion: This study shows that for high energy photon beams the doses at dmax are affected by the use of wedge filter, SSD and FS as confirmed by two different detectors.
    [Show full text]
  • Environment and Society
    Environment and Society Readings in Social and Environmental Studies The Faculty of Social and Environmental Studies Josai International University Gumyo 1, Togane City March 2015 Environment and Society Readings in Social and Environmental Studies The Faculty of Social and Environmental Studies Josai International University Gumyo 1, Togane City March 2015 Preface The Faculty of Social and Environmental Studies has established its educational goal as training global personnel who are of use in society by constructing “a sustainable society”, that balances society and the environment, under present circumstances marked by advancing global warming, the biodiversity crisis and other environmental issues that are appearing globally. Our faculty, is making use of its characteristic as an international university, to establish “The Global College” Programme based on an “All English” policy as a new faculty, and providing our students with diverse opportunities to take a second foreign language such as Germany or French, in order to improve their linguistic skills that are the foundation of English education, and in this way to promote global education. Furthermore, by cooperating with more than 140 overseas sister universities, we are nurturing a viewpoint that considers the environment from a global perspective by deepening international exchanges with foreign students and understanding of overseas cultures through short and long term overseas study and student exchanges. This textbook is an English summary of some of the results of education and research by our faculty edited mainly for students from abroad studying in our university to give them an accurate understanding of the contents of the education and research on the environment supplied by our faculty.
    [Show full text]
  • ACF-CG Agenda Item: 15-02-298 Charting Dmax (Service Volume)
    ACF-CG Agenda Item: 15-02-298 Charting Dmax (Service Volume) Proposed Addition from last meeting: DRAFT Order 8260.19H, paragraph 4-6-10j: f. GLS ground stations have varying service volumes, or what is known as “maximum use distance,” based on installation and siting. GLS “maximum use distance” is referred to as “Dmax.” Dmax is measured from the centroid of the ground GPS reference receiver antennas. Dmax is reported on the “Airport Details” Airport Datasheet. For GLS procedures, calculate where Dmax would occur on the procedure and include a waypoint (either existing or created to support this), which is at least 1 nm inside actual Dmax and annotate with “(DMAX)” label above the waypoint. This waypoint could be either a CNF or an existing waypoint. This waypoint is only for situational awareness and will be included on Form 8260-3/-7A so that it can be included on the approach chart. For example, “From MAKKO to KABBY (DMAX)” on Form 8260-3/-7A in the Terminal Routes section.” Federal Aviation 1 Administration ACF-CG Agenda Item: 15-02-298 Charting Dmax (Service Volume) (Continued) • AFS-400 Counter Proposal – Have criteria mandate procedure be developed to insure the intermediate segment is within the GLS service volume. – Since Intermediate Fix (IF) will always be within the GLS service volume, there is no need to specify Dmax location on the chart. – Similar concept as what is used for localizer service volume. – AIM/AIP and IPH guidance will be developed to explain application/concepts. Federal Aviation 2 Administration ACF-CG Agenda Item: 15-02-298 Charting Dmax (Service Volume) (Continued) • DRAFT Order 8260.58A, change 1, text: Federal Aviation 3 Administration .
    [Show full text]
  • Dosimetry for Food Irradiation
    Technical Reports Series No. 409 Dosimetry for Food Irradiation INTERNATIONAL ATOMIC ENERGY AGENCY, VIENNA, 2002 DOSIMETRY FOR FOOD IRRADIATION The following States are Members of the International Atomic Energy Agency: AFGHANISTAN GHANA PANAMA ALBANIA GREECE PARAGUAY ALGERIA GUATEMALA PERU ANGOLA HAITI PHILIPPINES ARGENTINA HOLY SEE POLAND ARMENIA HUNGARY PORTUGAL AUSTRALIA ICELAND QATAR AUSTRIA INDIA REPUBLIC OF MOLDOVA AZERBAIJAN INDONESIA ROMANIA BANGLADESH IRAN, ISLAMIC REPUBLIC OF RUSSIAN FEDERATION BELARUS IRAQ SAUDI ARABIA BELGIUM IRELAND SENEGAL BENIN ISRAEL SIERRA LEONE BOLIVIA ITALY SINGAPORE BOSNIA AND HERZEGOVINA JAMAICA SLOVAKIA BOTSWANA JAPAN SLOVENIA BRAZIL JORDAN SOUTH AFRICA BULGARIA KAZAKHSTAN SPAIN BURKINA FASO KENYA SRI LANKA CAMBODIA KOREA, REPUBLIC OF SUDAN CAMEROON KUWAIT SWEDEN CANADA LATVIA SWITZERLAND CENTRAL AFRICAN LEBANON SYRIAN ARAB REPUBLIC REPUBLIC LIBERIA TAJIKISTAN CHILE LIBYAN ARAB JAMAHIRIYA THAILAND CHINA LIECHTENSTEIN THE FORMER YUGOSLAV COLOMBIA LITHUANIA REPUBLIC OF MACEDONIA COSTA RICA LUXEMBOURG TUNISIA CÔTE D’IVOIRE MADAGASCAR TURKEY CROATIA MALAYSIA UGANDA CUBA MALI UKRAINE CYPRUS MALTA UNITED ARAB EMIRATES CZECH REPUBLIC MARSHALL ISLANDS UNITED KINGDOM OF DEMOCRATIC REPUBLIC MAURITIUS GREAT BRITAIN AND OF THE CONGO MEXICO NORTHERN IRELAND DENMARK MONACO UNITED REPUBLIC DOMINICAN REPUBLIC MONGOLIA OF TANZANIA ECUADOR MOROCCO UNITED STATES OF AMERICA EGYPT MYANMAR URUGUAY EL SALVADOR NAMIBIA UZBEKISTAN ESTONIA NETHERLANDS VENEZUELA ETHIOPIA NEW ZEALAND VIET NAM FINLAND NICARAGUA YEMEN FRANCE NIGER YUGOSLAVIA, GABON NIGERIA FEDERAL REPUBLIC OF GEORGIA NORWAY ZAMBIA GERMANY PAKISTAN ZIMBABWE The Agency’s Statute was approved on 23 October 1956 by the Conference on the Statute of the IAEA held at United Nations Headquarters, New York; it entered into force on 29 July 1957. The Headquarters of the Agency are situated in Vienna.
    [Show full text]
  • Airplane Flying Handbook (FAA-H-8083-3B) Chapter 15
    Chapter 15 Transition to Jet-Powered Airplanes Introduction This chapter contains an overview of jet powered airplane operations. The information contained in this chapter is meant to be a useful preparation for, and a supplement to, formal and structured jet airplane qualification training. The intent of this chapter is to provide information on the major differences a pilot will encounter when transitioning to jet powered airplanes. In order to achieve this in a logical manner, the major differences between jet powered airplanes and piston powered airplanes have been approached by addressing two distinct areas: differences in technology, or how the airplane itself differs; and differences in pilot technique, or how the pilot addresses the technological differences through the application of different techniques. For airplane-specific information, a pilot should refer to the FAA-approved Airplane Flight Manual for that airplane. 15-1 Jet Engine Basics Although the propeller-driven airplane is not nearly as efficient as the jet, particularly at the higher altitudes and cruising A jet engine is a gas turbine engine. A jet engine develops speeds required in modern aviation, one of the few advantages thrust by accelerating a relatively small mass of air to very the propeller-driven airplane has over the jet is that maximum high velocity, as opposed to a propeller, which develops thrust is available almost at the start of the takeoff roll. Initial thrust by accelerating a much larger mass of air to a much thrust output of the jet engine on takeoff is relatively lower slower velocity. and does not reach peak efficiency until the higher speeds.
    [Show full text]
  • Zulassungsantrag Der DMAX TV Gmbh & Co. KG Für Die
    Zulassungsantrag der DMAX TV GmbH & Co. KG für die Fernsehprogramme „Animal Planet”, „Discovery Channel”, „Discovery Geschichte” und „Discovery HD” Aktenzeichen: KEK 528 Beschluss In der Rundfunkangelegenheit der DMAX TV GmbH & Co. KG, vertreten durch die DMAX TV Verwaltungsgesell- schaft mbH, diese ihrerseits vertreten durch die Geschäftsführer Katja Hofem-Best und Magnus Kastner, Maximilianstraße 13, 80539 München, – Antragstellerin – Verfahrensbevollmächtigte: XXX... w e g e n Zulassung zur Veranstaltung der bundesweiten Fernsehspartenprogramme Animal Planet, Discovery Channel, Discovery Geschichte und Discovery HD hat die Kommission zur Ermittlung der Konzentration im Medienbereich (KEK) auf Vorlage der Bayerischen Landeszentrale für neue Medien (BLM) vom 03.11.2008 am 14.04.2009 unter Mitwirkung ihrer Mitglieder Prof. Dr. Sjurts (Vorsitzende), Prof. Dr. Huber (stv. Vorsit- zender), Albert, Dr. Bauer, Prof. Dr. Dörr, Prof. Dr. Gounalakis, Dr. Hege, Dr. Hornauer, Langheinrich, Dr. Lübbert und Prof. Dr. Schneider entschieden: Der von der DMAX TV GmbH & Co. KG mit Schreiben vom 20.10.2008 bei der Bayerischen Landeszentrale für neue Medien (BLM) beantragten Zulassung zur Veranstaltung der bundesweit verbreiteten Fernsehspartenprogramme Animal Planet, Discovery Channel, Discovery Geschichte und Discovery HD stehen Gründe der Sicherung der Meinungsvielfalt im Fernsehen nicht entgegen. 2 Begründung I Sachverhalt 1 Gegenstand der Anzeige Mit Schreiben vom 20.10.2008 haben die anwaltlichen Vertreter der Discovery Communications Deutschland GmbH („Discovery Communications Deutschland“) bei der BLM angezeigt, dass die Discovery Communications Deutschland auf Grundlage des Verschmelzungsvertrags vom 27.08.2008 und der Beschlüsse der Gesellschafterversammlung vom selben Tag auf die DMAX TV GmbH & Co. KG („DMAX TV“) verschmolzen wurde. Die Verschmelzung wurde am 06.10.2008 in das Handelsregister eingetragen.
    [Show full text]
  • Chapter 6 EXTERNAL PHOTON BEAMS
    Chapter 6 EXTERNAL PHOTON BEAMS: PHYSICAL ASPECTS E.B. PODGORSAK Department of Medical Physics, McGill University Health Centre, Montreal, Quebec, Canada 6.1. INTRODUCTION Radiotherapy procedures fall into two main categories: external beam radiotherapy and brachytherapy. In external beam radiotherapy the radiation source is at a certain distance from the patient and the target within the patient is irradiated with an external radiation beam. In brachytherapy (see Chapter 13) radiation sources are placed directly into the target volume (intracavitary or interstitial brachytherapy) or on to a target (surface mould or intraoperative radiotherapy). Most external beam radiotherapy is carried out with photon beams, some with electron beams and a very small fraction with more exotic particles such as protons, heavier ions or neutrons. This chapter deals with external photon beam radiotherapy. Photon external beams are all characterized by the same physical parameters, but fall into various categories depending on their origin, means of production and energy. There are two origins of photon beams: g rays, which originate from radioactive nuclei, and X rays, which originate in a target bombarded with energetic electrons. The X rays from a target consist of bremsstrahlung photons and characteristic photons. X rays are produced either in an X ray tube (super- ficial or orthovoltage X rays) or in a linac (megavoltage X rays). 6.2. QUANTITIES USED IN DESCRIBING A PHOTON BEAM Radiation dosimetry deals with two distinctly different entities: one describes the photon radiation beam itself in terms of the number and energies of photons constituting the photon beam and the other describes the amount of energy the photon beam may deposit in a given medium such as air, water or biological material.
    [Show full text]