Defense Date
2024
Document Type
Thesis
Degree Name
Master of Science
Department
Radiation Oncology
First Advisor
Siyong Kim
Second Advisor
William Song
Third Advisor
Chris Bartee
Abstract
Purpose:
In this work we test the Optically Stimulated Luminescent (OSL) film dosimeter’s different characteristics such as Monitor Unit (MU) linearity, dose rate dependence, and determined its viability for In Vivo Dosimetry (IVD).
Methods:
A prototype BaFBr OSL film was cut into 6 even pieces and the pieces were irradiated on a Trilogy 21EX Varian linac and tested for different characteristics. The standard setup was 6 MV photon beam, with gantry and collimator at 0,10 cm depth and 1.5 cm back scatter. The reader warmup time and fading were calculated, and a standard time was determined and used for the remainder of the tests.
Results:
Repeated measurements on the same film show up to a 1% error in reproducibility. Dose rate is consistent at 1% variation up to 600 MU/min. MU response is linear within 3.5% until 2000 MU. The sensitivity of the film varied depending on the section of film irradiated, leading to errors of up to 7% for different films. When tested for in vivo dosimetry, the percent error in the OSL film was 0.73% at 500 MU, compared to nanodot Optically Stimulated Luminescent Dosimeter (OSLD) which was 3.5% difference.
Conclusion:
The early stages of OSL film trials show promise in the future, but work needs to be done to make the accuracy and reproducibility better for clinical use. The issues that arose in the in vivo tests are upsetting, however that does not mean that this film is unusable in other areas of dosimetry in the future.
Rights
© The Author
Is Part Of
VCU University Archives
Is Part Of
VCU Theses and Dissertations
Date of Submission
5-6-2024