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dc.contributor.authorLai, Ingrid
dc.contributor.otherQueen's University (Kingston, Ont.). Theses (Queen's University (Kingston, Ont.))en
dc.date.accessioned2018-10-01T21:20:41Z
dc.date.available2018-10-01T21:20:41Z
dc.identifier.urihttp://hdl.handle.net/1974/24929
dc.description.abstractTotal body irradiation (TBI) is used in the treatment of certain types of blood cancers. It involves irradiating the whole body of the patient with high energy x-rays or gamma rays in order to kill cancer cells and suppress the immune system in preparation for a stem cell or bone marrow transplant. The challenge in TBI is delivering a uniform dose throughout the whole patient. Most conventional cancer treatment units are not able to provide a sufficiently large uniform radiation field to enable TBI without complex movement of the beam or the patient. Recently, a dedicated Co-60 TBI unit was developed in Canada by BEST Theratronics (Kanata, ON). It uses gamma radiation from a Co-60 source housed in an extended gantry to irradiate a stationary patient lying on a couch below the source. The radiation beam of the source needs to be modified by a filter between the source and the patient to ensure uniform irradiation over the whole patient length as the distance from source varies considerably over the treatment volume. The amount of filtration required may also change over time to ensure an appropriate dose rate is maintained as the source decays. To assist BEST Theratronics with filter design, Monte Carlo (MC) simulations for the TBI unit were run to test the effectiveness of filter shapes that they had calculated by hand. This was a time consuming, trial-and-error process which required specialised training. It was the motivation for the development of a filter optimisation program which uses a radiation transport model based on primary and first scatter dose contributions that is quicker and easy to use. It was found that the relative dose distributions calculated by this program matched the MC-calculated distributions within about 3%. The absolute dose calculated was accurate for a small field and phantom, but for the TBI unit and a large phantom, the absolute dose was underestimated by 24-38% because of the missing higher order scatter. However, the amount of underestimation is predictable, so it is possible to use the program to calculate acceptable beam flattening filter shapes for a particular desired dose rate.en_US
dc.language.isoenen_US
dc.relation.ispartofseriesCanadian thesesen
dc.rightsQueen's University's Thesis/Dissertation Non-Exclusive License for Deposit to QSpace and Library and Archives Canadaen
dc.rightsProQuest PhD and Master's Theses International Dissemination Agreementen
dc.rightsIntellectual Property Guidelines at Queen's Universityen
dc.rightsCopying and Preserving Your Thesisen
dc.rightsThis publication is made available by the authority of the copyright owner solely for the purpose of private study and research and may not be copied or reproduced except as permitted by the copyright laws without written authority from the copyright owner.en
dc.subjectMonte Carloen_US
dc.subjectmedical physicsen_US
dc.subjecttotal body irradiationen_US
dc.subjectradiation therapyen_US
dc.subjectflattening filteren_US
dc.subjectfirst scatteren_US
dc.subjectabsorbed doseen_US
dc.subjectradiation doseen_US
dc.subjectfilter optimisationen_US
dc.subjectEGSnrcen_US
dc.subjectdose rateen_US
dc.subjectcobalt-60en_US
dc.subjectCo-60en_US
dc.subjectradiation transporten_US
dc.titleMonte Carlo modelling and optimisation of flattening filters for a novel Co-60 total body irradiation uniten_US
dc.typeThesisen
dc.description.degreeMaster of Scienceen_US
dc.contributor.supervisorSchreiner, L. John
dc.contributor.supervisorJoshi, Chandra
dc.contributor.departmentPhysics, Engineering Physics and Astronomyen_US


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