SUBJECT: M.S. Thesis Presentation
BY: Bashar Ziadat
TIME: Friday, April 19, 2024, 2:30 p.m.
TITLE: Assessment of Optimal Spoiler Thickness for Total Body Irradiation Utilizing Tomotherapy Technology
COMMITTEE: Dr. Chris Wang, Co-Chair (NRE)
Dr. Steven Biegalski, Co-Chair (NRE)
Dr. Farshad Mostafaei (Radiation Oncology)
Dr. Chulhaeng Huh (Radiation Oncology)


This study investigates the application of Monte Carlo (MC) simulation for optimizing dose distribution in radiotherapy treatments. A patient was simulated using a 35, 15-year-old male phantom from the National Institutes of Health (NIH) database and an ArcCHECK dosimeter. The study evaluated the dosimetric impact of Acrylic ring spoilers with varying thicknesses (0, 0.25, 0.375, and 0.625 inches) on a modified ArcCHECK dosimeter system. TOPAS software was utilized for MC simulations, allowing for comparison with treatment plans generated by a Treatment Planning System (TPS) incorporating the same spoiler configurations. The primary objective was to achieve an optimal dose distribution while minimizing irradiation of lung tissue. EBT3 films were used for dosimetric measurements of both lung and skin doses. Film dosimetry was performed using a dose calibration curve to convert the measured film response into absolute dose. Additionally, an ion chamber was integrated within the ArcCHECK dosimeter for independent measurement of lung dose.
This study contributes to the field of radiotherapy by investigating the potential of MC simulations for optimizing dose distributions and minimizing lung irradiation and maximizing the skin dose. the findings compare the lungs and skin dose obtained by each spoiler thickness to achieve the best dose distribution. The study also explores the use of EBT3 films for treatment verification and ion chamber measurements for in-situ lung dose assessment within the ArcCHECK dosimeter.