Date Approved
8-6-2025
Graduate Degree Type
Project
Degree Name
Medical Dosimetry (M.S.)
Degree Program
Health Professions
First Advisor
Sarah Johnson
Second Advisor
Kristen Vu
Academic Year
2024/2025
Abstract
Introduction: Hypo-Fractionated Radiation Therapy (HFRT) of the breast administers larger doses per session over a shorter timeframe, often completing treatment in 3–4 weeks. The use of HFRT of the breast has been a breakthrough in breast cancer treatment, where whole-breast irradiation following breast-conserving surgery has become a standard approach. It is important to assess the dosimetric effect of modesty coverings affect the dose at the surface and at the isocenter. By finding the results of how these modesty coverings affect the dose, it can be documented that patients should not be covered with modesty coverings in the treatment field to ensure proper treatment. This study will find a better understanding of whether these modesty coverings have any effect on the dose at the surface and at the isocenter for HFRT for breast patient treatment plans.
Methods: The researchers used a solid water phantom to calculate the dose difference in Varian Eclipse version 16.1 and used an ion chamber on the linear accelerator to see the actual difference under the linear accelerator. The modesty coverings (blanket, gown, sheet, and towel) were contoured in Eclipse and incorporated into the treatment plan for each modesty covering to evaluate the differences using Acuros 13.5.
Results: The study demonstrated that depending on the type of modesty coverings that were used during HFRT significantly affected the dose to the patient. The “nothing” covering exhibited the lowest and most accurate dose, reinforcing its role as a dosimetric baseline in this study.
Conclusion: To maintain dosimetric accuracy, it is best to avoid covering any patient with any modesty coverings. The findings indicate that modesty coverings can introduce clinically relevant alterations in dose distribution during HFRT. Although these coverings help with patient comfort and dignity, they can also alter dosimetric accuracy. Further research should be done, and it is recommended to show the dosimetric precision in HFRT.
ScholarWorks Citation
Cofer, Christopher Neal, "Impact of Modesty Coverings on Isocenter Dose and Surface Dose in Hypo-fractionated Breast Treatment (HFRT)" (2025). Culminating Experience Projects. 643.
https://scholarworks.gvsu.edu/gradprojects/643
