Brent Foy (Advisor), Michael Gossman (Advisor), Thomas Skinner (Committee Member)
Master of Science (MS)
There exists a lack of accurate, reproducible three-dimensional dosimetry techniques for stereotactic radiosurgery (SRS) commissioning and quality assurance. This experiment evaluates the use of ClearView gel dosimeters as an alternative to current methods for small field dosimetry in SRS testing. ClearView differs from other gel dosimeters in that it uses tetrazolium salt in its chemical make-up in place of traditional Fricke-type compounds. Using a Varian TrueBeam radiotherapy system to deliver the radiation, three vials of ClearView gel dosimeter were tested in three different dose delivery scenarios. The first test examined the dosimeter's response to a static beam with the dose isocenter targeted to the centroid of the vial. The second evaluation consisted of a full rotational SRS delivery about the center of the dosimeter. Lastly, a complete end-to-end treatment plan was performed to evaluate the accuracy of the dosimeter in a full SRS procedure. The three dosimeters were then scanned to measure the dose distribution throughout the gel. Finally, the resulting data was compared to the initial treatment plan to determine the accuracy of the gel. According to the comparisons performed, the ClearView gel showed capability of sub-millimeter spatial accuracy across the three evaluations, with a maximum geometric uncertainty of 1.2 mm. Based on these results, ClearView gel shows promise for possible use in SRS dosimetry applications in clinical settings.
Department or Program
Department of Physics
Year Degree Awarded
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