Download or read book Readout of Polymer Gel Dosimeters Using a Prototype Fan-beam Optical Computed Tomography Scanner written by Warren Gerard Campbell and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: New radiation therapy (RT) techniques for treating cancer are continually under development. Our ability to demonstrate the safe and accurate implementation of new RT treatment techniques is dependent on the information provided by current dosimetric tools. Advanced dosimetric tools will become increasingly necessary as treatments become more complex. This work examines the readout of an advanced dosimeter -- the polyacrylamide, gelatin, and tetrakis (hydroxymethyl) phosphonium chloride (PAGAT) dosimeter -- using a prototype fan-beam optical computed tomography (CT) scanner.A number of developments sought to improve the performance of the optical CT device. A new fan-creation method (laser diode module) and new matching tank were introduced. Artefact removal techniques were developed to remove flask seam artefacts and ring artefacts via sinogram space. A flask registration technique was established to achieve reproducible placement of flasks in the optical CT scanner. A timing-correction technique was implemented to allow for the scanning of continuously rotating samples. A number of experiments examined factors related to the PAGAT dosimeter. Comparisons of post-irradiation scans to pre-irradiation scans improved dosimeter readout quality. Changes to the PAGAT dosimeter cooling/scanning routine provided further improvements to dosimeter readout. Evaluations of calibration curves showed that a linear calibration curve was less capable of describing PAGAT dose response than a quadratic calibration curve. Intra-gel calibration using another dose distribution was shown to be no less accurate than self calibration, but inter-gel calibrations saw a statistically significant increase in absolute readout errors.