Biological Effects and Equivalent Doses in Radiotherapy: a Software Solution
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Time, Dose and Fractionation in Radiotherapy
2/25/2013 The introduction of Fractionation 2-13/13 Radiobiology lecture Time, Dose and Fractionation in Radiotherapy The Four Rs of Radiobiology Repair of Sublethal Damage • Cells exposed to sparse radiation experience • Efficacy of fractionation based on the 4 Rs: sublethal injury that can be repaired – Repair of sublethal damage • Cell killing requires a greater total dose when given –Repopulation in several fractions – Reassortment of cells within the cell cycle • Most tissue repair occurs in about 3 hours and up –Reoxygenation to 24 hours post radiation • Allows for repair of injured normal tissue and gives a potential therapeutic advantage over tumor cells Reoxygenation Redistribution • Oxygen stabilizes free radicals • Position in cell cycle at time of radiation • Hypoxic cells require more radiation to kill determines sensitivity •Hypoxic tumors • S phase is radioresistant – Temporary vessel constriction •G2 phase delay results in increased radiation – Outgrowth of blood supply and capillary collapse resistance • Tumor shrinkage reduces hypoxic areas • Fractionated RT redistributes cells • Reinforces fractionated dosing • Rapidly cycling cells like mucosa, skin are more sensitive • Slower cyclers like connective tissue, brain are spared 1 2/25/2013 Repopulation • Increased regeneration of surviving fraction Basics of Fractionation • Rapidly proliferating tumors regenerate faster • Determines the length and timing of therapy course • Dividing a dose into several fractions spares normal tissues • Accelerated Repopulation – Repair -
Nuclear Radiation 1. an Atom Contains Electrons, Protons and Neutrons
Nuclear Radiation 1. An atom contains electrons, protons and neutrons. Which of these particles a) are outside the nucleus b) are uncharged c) have a negative charge d) are nucleons e) are much lighter than the others? 2. Complete the table below. Name Symbol Charge What is it? Alpha particle β -1 Gamma ray An electromagnetic wave 3. How is an ionised material different from a material that is not ionised? National 5 Physics: Waves & Radiation 1 Absorption of Radiation 1. The figure below shows a Geiger tube used to detect radiation from a radioactive source. thick lead plate 0 4 2 5 start counter stop ON OFF reset Geiger tube radioactive source The following measurements were made using the apparatus above. Counts in 300 seconds Readings Average 1 No source present 102 94 110 2 Source present at fixed distance from tube a) No lead plate present 3466 3420 3410 b) Thick lead plate present 105 109 89 c) Aluminium sheet in place of the 1834 1787 1818 thick lead sheet a) Complete the table by calculating the average readings. b) Why are the readings on each line not the same? c) What can you say from the table about the effect on the radiation of: i. The lead plate? ii. The aluminium plate? d) Why is it possible to say from the readings that: i. gamma radiation is emitted by the source? ii. alpha and beta radiation might be emitted by the source? e) What further tests could you make using this arrangement to find out whether or not the source emits alpha radiation? National 5 Physics: Waves & Radiation 2 2. -
Copyright by Arthur Bryan Crawford 2004
Copyright by Arthur Bryan Crawford 2004 The Dissertation Committee for Arthur Bryan Crawford Certifies that this is the approved version of the following dissertation: Evaluation of the Impact of Non -Uniform Neutron Radiation Fields on the Do se Received by Glove Box Radiation Workers Committee: Steven Biegalski, Supervisor Sheldon Landsberger John Howell Ofodike Ezekoye Sukesh Aghara Evaluation of the Impact of Non -Uniform Neutron Radiation Fields on the Dose Received by Glove Box Radiation Workers by Arthur Bryan Crawford, B.S., M.S. Dissertation Presented to the Faculty of the Graduate School of The University of Texas at Austin in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy The University of Texas at Austin December, 2004 Dedication I was born to goodly parents Harvey E. Crawford and Johnnie Lee Young Crawford Acknowledgements I would like to express my gratitude to Dr. Sheldon Landsberger for his vision in starting a distance learning program at the University of Texas at Austin and for his support and encouragement on this quest. I would like to thank my advisor, Dr. Steven Biegalski, for his support and encouragement even though the topic area was new to him. I would like to thank the members of my dissertation committee for finding the time to review this dissertation. To the staff of the Nuclear Engineering Teaching Laboratory I say thank you for your kindness and support during those brief times that I was on cam pus. A special thanks to my past and present group leaders, David Seidel, Eric McNamara, and Bill Eisele and my Division Leader, Lee McAtee, at Los Alamos National Laboratory, for their support in being allowed to use time and material resources at the Lab oratory and for financial support in the form of tuition reimbursement and travel expenses. -
Radiobiology Is a Young Science and Is Solely Concerned with the Study Of
The Rockefeller Foundation and its support of Radiobiology up to the 1970s By Sinclair Wynchank Senior Lecturer University of Cape Town Rondebosch, South Africa [email protected] © 2011 by Sinclair Wynchank Radiation biology, or radiobiology, is a very young science, solely concerned with the study of the interactions between ionizing radiation and living matter. This science slowly became a recognized field of study after the discovery of ionizing radiation (i.e., X rays) in 1895. A broadly varied and evolving terminology has been applied to aspects of radiobiology and therefore, archival searches concerning it are complex. This report is a work in progress, which mainly recounts support given by the Rockefeller Foundation (RF) to radiobiology. The RF was a most important player in the early history of radiobiology and a crucial influence in ensuring that the science steadily matured during its first six decades. Time constraints prevented all relevant items from being accessed, but a clear idea of the RF‟s strong influence on radiobiology‟s early history has resulted. Examples of RF activities to verify this assertion are given below, in by and large chronological order. After a brief analysis of RF aid, there is a short account of why its support so strongly benefitted the young science. To my knowledge there is very little written about the history of radiobiology and nothing about the role that the RF or other philanthropic bodies played in this history. Inevitably, for an extensive time, individual radiobiologists first studied other fields of science before radiobiology. Even in 2011 there are only five universities in the U.S. -
General Guidelines for the Estimation of Committed Effective Dose from Incorporation Monitoring Data
Forschungszentrum Karlsruhe in der Helmholtz-Gemeinschaftt Wissenschaftliche Berichte FZKA 7243 General Guidelines for the Estimation of Committed Effective Dose from Incorporation Monitoring Data (Project IDEAS – EU Contract No. FIKR-CT2001-00160) H. Doerfel, A. Andrasi, M. Bailey, V. Berkovski, E. Blanchardon, C.-M. Castellani, C. Hurtgen, B. LeGuen, I. Malatova, J. Marsh, J. Stather Hauptabteilung Sicherheit August 2006 Forschungszentrum Karlsruhe in der Helmholtz-Gemeinschaft Wissenschaftliche Berichte FZKA 7243 GENERAL GUIDELINES FOR THE ESTIMATION OF COMMITTED EFFECTIVE DOSE FROM INCORPORATION MONITORING DATA (Project IDEAS – EU Contract No. FIKR-CT2001-00160) H. Doerfel, A. Andrasi 1, M. Bailey 2, V. Berkovski 3, E. Blanchardon 6, C.-M. Castellani 4, C. Hurtgen 5, B. LeGuen 7, I. Malatova 8, J. Marsh 2, J. Stather 2 Hauptabteilung Sicherheit 1 KFKI Atomic Energy Research Institute, Budapest, Hungary 2 Health Protection Agency, Radiation Protection Division, (formerly National Radiological Protection Board), Chilton, Didcot, United Kingdom 3 Radiation Protection Institute, Kiev, Ukraine 4 ENEA Institute for Radiation Protection, Bologna, Italy 5 Belgian Nuclear Research Centre, Mol, Belgium 7 Institut de Radioprotection et de Sûreté Nucléaire, Fontenay-aux-Roses, France 8 Electricité de France (EDF), Saint-Denis, France 9 National Radiation Protection Institute, Praha, Czech Republic Forschungszentrum Karlsruhe GmbH, Karlsruhe 2006 Für diesen Bericht behalten wir uns alle Rechte vor Forschungszentrum Karlsruhe GmbH Postfach 3640, 76021 Karlsruhe Mitglied der Hermann von Helmholtz-Gemeinschaft Deutscher Forschungszentren (HGF) ISSN 0947-8620 urn:nbn:de:0005-072434 IDEAS General Guidelines – June 2006 Abstract Doses from intakes of radionuclides cannot be measured but must be assessed from monitoring, such as whole body counting or urinary excretion measurements. -
The International Commission on Radiological Protection: Historical Overview
Topical report The International Commission on Radiological Protection: Historical overview The ICRP is revising its basic recommendations by Dr H. Smith Within a few weeks of Roentgen's discovery of gamma rays; 1.5 roentgen per working week for radia- X-rays, the potential of the technique for diagnosing tion, affecting only superficial tissues; and 0.03 roentgen fractures became apparent, but acute adverse effects per working week for neutrons. (such as hair loss, erythema, and dermatitis) made hospital personnel aware of the need to avoid over- Recommendations in the 1950s exposure. Similar undesirable acute effects were By then, it was accepted that the roentgen was reported shortly after the discovery of radium and its inappropriate as a measure of exposure. In 1953, the medical applications. Notwithstanding these observa- ICRU recommended that limits of exposure should be tions, protection of staff exposed to X-rays and gamma based on consideration of the energy absorbed in tissues rays from radium was poorly co-ordinated. and introduced the rad (radiation absorbed dose) as a The British X-ray and Radium Protection Committee unit of absorbed dose (that is, energy imparted by radia- and the American Roentgen Ray Society proposed tion to a unit mass of tissue). In 1954, the ICRP general radiation protection recommendations in the introduced the rem (roentgen equivalent man) as a unit early 1920s. In 1925, at the First International Congress of absorbed dose weighted for the way different types of of Radiology, the need for quantifying exposure was radiation distribute energy in tissue (called the dose recognized. As a result, in 1928 the roentgen was equivalent in 1966). -
Radiation and Cell Cycle
High Yield Summary Reviews in Radiation Oncology Radiation and Cancer Biology Gayle E. Woloschak, PhD Tuesday, June 18, 2019 11:00 a.m. – 1:00 p.m. Eastern Daylight Time June 25, 2019 Gayle E. Woloschak PhD Professor of Radiation Oncology, Radiology, and Cell & Molecular Biology Associate Dean for Graduate Student and Postdoctoral Affairs Northwestern University Feinberg School of Medicine June 25, 2019 Definitions • Bq-2.7x10-11 Ci—equal to one disintegration per sec • Ci—3.7x1010 disintegrations per sec • Gy—absorbed radiation dose, the quantity which deposits 1 Joule of energy per kg—1Gy=100rad • Sievert—dose equivalence—multiply absorbed dose in Gy by the Quality Factor (Q)— 1Sv=100rem • LET—measure of the rate of energy transfer from an ionizing radiation to the target material—keV of energy lost/micron track length Unit Conversion Factors: SI and Conventional Units • 1 Bq = 2.7 × 10–11 Ci = 27 pCi • 1 Ci = 3.7 × 1010 Bq = 37 GBq • 1 Sv = 100 rem • 1 rem = 0.01 Sv • 1 Gy = 100 rad • 1 rad = 0.01 Gy • 1 Sv Bq–1 = 3.7 × 106 rem μCi–1 • 1 rem μCi–1 = 2.7 × 10–7 Sv Bq–1 • 1 Gy Bq–1 = 3,7 × 106 rad μCi–1 • 1 rad μCi–1 = 2,7 × 10–7 Gy Bq–1 Biomolecular Action of Ionizing Radiation; Editor:Shirley Lehnert, 2007 Units Used in Radiation Protection • Equivalent dose—average dose x radiation weighting factor—Sv • Effective dose—sum of equivalent doses to organs and tissues exposed, each multiplied by the appropriate tissue weighting factor—Sv • Committed equivalent dose—equivalent dose integrated over 50 years (relevant to incroporated radionuclides)—Sv -
Proton Radiobiology
Cancers 2015, 7, 353-381; doi:10.3390/cancers7010353 OPEN ACCESS cancers ISSN 2072-6694 www.mdpi.com/journal/cancers Review Proton Radiobiology Francesco Tommasino 1 and Marco Durante 1,2,* 1 GSI Helmholtzzentrum für Schwerionenforschung, Department of Biophysics, Darmstadt 64291, Germany; E-Mail: [email protected] 2 Technische Universität Darmstadt, Institut für Festkörperphysik, Darmstadt 64291, Germany * Author to whom correspondence should be addressed; E-Mail: [email protected]; Tel.: +49-6159-71-2009. Academic Editor: Xiaodong Zhang Received: 3 December 2014 / Accepted: 9 February 2015 / Published: 12 February 2015 Abstract: In addition to the physical advantages (Bragg peak), the use of charged particles in cancer therapy can be associated with distinct biological effects compared to X-rays. While heavy ions (densely ionizing radiation) are known to have an energy- and charge-dependent increased Relative Biological Effectiveness (RBE), protons should not be very different from sparsely ionizing photons. A slightly increased biological effectiveness is taken into account in proton treatment planning by assuming a fixed RBE of 1.1 for the whole radiation field. However, data emerging from recent studies suggest that, for several end points of clinical relevance, the biological response is differentially modulated by protons compared to photons. In parallel, research in the field of medical physics highlighted how variations in RBE that are currently neglected might actually result in deposition of significant doses in healthy organs. This seems to be relevant in particular for normal tissues in the entrance region and for organs at risk close behind the tumor. All these aspects will be considered and discussed in this review, highlighting how a re-discussion of the role of a variable RBE in proton therapy might be well-timed. -
Overview and Basis of Design for NCRP Report
This Report was prepared through a joint effort of NCRP Scientific Committee 46-13 on Design of Facilities for Medical Radiation Overview & Basis of Design for NCRP Therapy and AAPM Task Group 57. Report 151 James A. Deye, Chairman James E. Rodgers, Vice Chair Raymond K. Wu, Vice Chair Structural Shielding Design and Evaluation for Peter J. Biggs Patton H. McGinley Megavoltage x- and Gamma-ray Radiotherapy Facilities Richard C. McCall Liaisons Kenneth R. Kase Marc Edwards Raymond K. Wu, PhD Consultants OhioHealth Hospitals Robert O. Gorson Jeffrey H. Kleck Nisy E. Ipe Columbus, OH Secretariat Marvin Rosenstein Eric E. Kearsley Learn • Calculation methods • W, U, T, IDR, TADR, RW, Rh, • Dose at maze door • Neutron, capture gamma at door • Laminated primary barrier This Report addresses the structural shielding design New Issues since NCRP # 49 and evaluation for medical use of megavoltage x- and gamma-rays for radiotherapy and supersedes related – New types of equipment, material in NCRP Report No. 49, Structural Shielding – Some with energies above 10 MV, Design and Evaluation for Medical Use of X Rays and Gamma Rays of Energies Up to 10 MeV, which was – Many new uses for radiotherapy equipment, issued in September 1976. – Dual energy machines, The descriptive information in NCRP Report No. 49 unique to x-ray therapy installations of less than 500 – Room designs without mazes, kV (Section 6.2) and brachytherapy is not included in – Varied shielding materials including composites, this Report and that information in NCRP Report No. 49 for those categories is still applicable. – More published data on empirical methods. -
Radiological Emissions-I
Radiological Emissions-I Ghulam Rasul Athar Applied Systems Analysis Group, Pakistan Atomic Energy Commission, P.O. Box 1114, Islamabad, Pakistan [email protected] IAEA Workshop on the ‘Use of the SimPacts Model for Estimating Human Health and Environmental Damages from Electricity Generation’ Trieste, Italy, May 12-23, 2003. Overview of the Presentation • Explanation of some terms used in radiation protection • Nuclear fuel cycle • NukPacts Becquerel (Bq) Becquerel is the basic unit of radioactivity. One Becquerel is equal to one disintegration per second. 1 Bq=2.7E-11 Ci One Ci = 3.7E+10 Bq Absorbed Dose When ionizing radiation interacts with the human body, it gives its energy to the body tissues. The amount of energy absorbed per unit weight of the organ or tissue is called absorbed dose. Absorbed dose is expressed in units of gray (Gy). One gray dose is equivalent to one joule radiation energy absorbed per kilogram of organ or tissue weight. Rad is the old and still used unit of absorbed dose. One gray is equivalent to 100 rads. (1 Gy = 100 rads) Equivalent Dose • Equal doses of all types of ionizing radiation are not equally harmful. • Alpha particles produce greater harm than do beta particles, gamma rays and x rays for a given absorbed dose. • To account for this difference, radiation dose is expressed as equivalent dose. • Equivqlent Dose is equal to "absorbed dose" multiplied by a "radiation weighting factor" (WR). • Equivalent Dose is measured in Sievert (Sv). • The dose in Sv (Equivalent Dose) = Dose x WR. • Prior to 1990, this weighting factor was referred to as Quality Factor (QF). -
Radiobiology
The Management of Gynecologic Cancers: Radiobiology Brian Marples PhD Beaumont Health Systems Overview of presentation • Assessment of normal tissue response • Radiobiology modeling • Role of HPV in tumor response • Hypoxic and tumor response Radiobiology and normal tissue response and tolerance • The Emami paper (IJROBP 21: 109–122 1991) – 1/3, 2/3, whole organs - some clinical, some laboratory data – Consensus of clinical experience and opinions – Concerns with delivered dose and measurements of dose – Out of date: Move from 2D to 3D treatment planning, higher energy beams, better penetration, improved ability to measure dose, increased use combined therapy • Quantitative – QUANTEC, CTCAE v4.0, LENT-SOMA, IIEF – Quantitative Analysis of Normal Tissue Effects in the Clinic – Updated guidelines published in Red Journal • IJROBP vol 76, No., 3 2010 (suppl.) – 16 organ-specific papers – Radiation dose-volume effects of the urinary bladder • Viswanathan et al. IJROBP 76: 3: S116–S122, 2010 • Cervix BRT: size of 60-Gy volume and dose rate have impact on late rectal complication BED = Biologically Effective Dose • BED commonly used for isoeffective dose calculations • BED is a measure of the true biological dose delivered by a particular combination of dose per fraction and total dose to a particular tissue characterized by a specific α/β ratio • BED is not Biologically Equivalent Dose • Biologically equivalent doses are calculated in 2-Gy equivalents using the EQD2 equation • Cumulative: brachytherapy dose added to the dose from external beam therapy Bentzen et al., Radiother Oncol 105: 266–268, 2012 Dale, Br J Radiol 58: 515–528, 1985 Biologically Effective Dose (BED) • BED compare effects fractionation schedules – need to know α/β ratio of the tissues concerned BED = total dose . -
National 5 Physics Unit 2 Waves & Radiation Section 2 Nuclear Radiation Problem Booklet
North Berwick High School Department of Physics National 5 Physics Unit 2 Waves & Radiation Section 2 Nuclear Radiation Problem Booklet Author: S Belford 2 Contents Topic Page Properties of Radiation 4 - 5 Activity 6 - 7 Half Life 8 - 9 Absorbed Dose 10 Equivalent Dose 11 - 13 Nuclear Fission and Fusion 14 Author: S Belford 3 Properties of Radiation 1. Describe the internal structure of the atom. 2. Describe what the following radiations are made up of. Include symbols. (a) Alpha (b) Beta (c) Gamma 3. What is the meaning of the term ‘ionisation’? 4. Copy and complete this table to show the absorption of radiation as they travel through different materials. Absorbing material Piece of 3 cm of 3 cm of Radiation 3 cm of Air Paper Aluminium Lead Alpha Beta Gamma Put a if the radiation will pass through the material. Put a x if the radiation will be absorbed by the material. 5. Give three safety precautions that should be followed when working with radioactive materials. 6. What is background radiation? Author: S Belford 4 7. What are the main sources of background radiation? 8. Is background radiation mostly naturally occurring or man-made? 9. What effect does radiation have on living cells? 10. Smoke alarms are made with an alpha source (Americium-241). Describe how a smoke alarm uses ionisation to warn people of a possible fire. 11. A radioactive tracer is a gamma emitting chemical compound that can be injected in to a patient in hospital. Describe how this can be useful in diagnosis of medical problems.