Date Approved

8-7-2022

Graduate Degree Type

Project

Degree Name

Health Sciences (M.H.S.)

Degree Program

Health Professions

First Advisor

Ina Sala

Academic Year

2021/2022

Abstract

In cases of breast radiation treatments via external beam radiation therapy, the incidence of radiation dermatitis has been reported. In prior studies, this acute radiation side-effect has been correlated with the immobilization devices in cases of prone breast irradiation. They attribute this to the bolus effect that occurs with the interaction of the incident photon beam at different projections causing an increase in measured surface dose. The type of radiation planning technique, and patient positioning during the undertaking of these techniques, have also shown to influence this bolus effect. This study focuses on these factors in treatment planning in order to reduce the issue of bolus effect in the inframammary fold. Standard 3D conformal, a non-coplanar, and IMRT techniques are employed to evaluate effectiveness in counteracting the inherent bolus effect. The resulting data recorded via MOSFET dosimeters failed to show a significant difference between standard 3D technique and non-coplanar technique. However, IMRT/VMAT technique showed significant differences between the 3D planning techniques, even with the alteration of patient positioning. These results show promise in utilizing IMRT planning techniques as a pre-emptive practice for reducing the chance of acute skin dermatitis in prone breast radiation therapy. Future studies should consider these findings, along with the discussed limitations, to examine potential improvements in research methods in evaluating increased surface dose during breast radiation therapy.

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