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

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