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dc.contributor.authorOlding, Timothy
dc.contributor.otherQueen's University (Kingston, Ont.). Theses (Queen's University (Kingston, Ont.))en
dc.date2010-09-02 15:01:48.501en
dc.date.accessioned2010-09-02T20:22:29Z
dc.date.available2010-09-02T20:22:29Z
dc.date.issued2010-09-02T20:22:29Z
dc.identifier.urihttp://hdl.handle.net/1974/6019
dc.descriptionThesis (Ph.D, Physics, Engineering Physics and Astronomy) -- Queen's University, 2010-09-02 15:01:48.501en
dc.description.abstractThe complex dose distributions delivered by modern, conformal radiation therapy techniques present a considerable challenge in dose verification. Traditional measurement tools are difficult and laborious to use, since complete verification requires that the doses be determined in three dimensions (3D). The difficulty is further complicated by a required target accuracy of ± 5% for the dose delivery. Gel dosimetry is an attractive option for realizing a tissue-equivalent, 3D dose verification tool with high resolution readout capabilities. However, much important work remains to be completed prior to its acceptance in the clinic. The careful development of easily accessible, fast optical readout tools such as cone beam optical computed tomography (CT) in combination with stable and reliable low-toxicity gel dosimeters is one key step in this process. In this thesis, the performance capabilities and limitations of the two main classes of cone beam optical CT-based absorbing and scattering gel dosimetry are characterized, and their measurement improved through careful matching of dosimeter and scanner performance. These systems are then applied to the evaluation of clinically relevant complex dose distributions. Three-dimensional quality assurance assessments of complex treatment plan dose distributions are shown to be feasible using an optically absorbing Fricke-xylenol-orange-gelatin-based gel dosimeter. Better than 95% voxel agreement is achieved between the plan and the delivery, using 3% dose difference and 3 mm spatial distance-to-agreement gamma function comparison criteria. Small field dose delivery evaluations are demonstrated to be viable using an optically scattering N-isopropylacrylamide (NIPAM)-based polymer gel, with the same comparison criteria. Full treatment process quality assurance is also possible using a NIPAM dosimeter in-phantom, but is limited in its accuracy due to the inherent difficulty of managing the effects of stray light pertubation in the optical attenuation-to-dose calibration.en
dc.languageenen
dc.language.isoenen
dc.relation.ispartofseriesCanadian thesesen
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.subjectoptical computed tomographyen
dc.subjectgel dosimetryen
dc.subjectradiation therapyen
dc.subject3D doseen
dc.titleCONE BEAM OPTICAL COMPUTED TOMOGRAPHY-BASED GEL DOSIMETRYen
dc.typeThesisen
dc.description.degreePh.Den
dc.contributor.supervisorSchreiner, John L.en
dc.contributor.departmentPhysics, Engineering Physics and Astronomyen


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