Skin Surface Dose for Whole Breast Radiotherapy Using Personalized Breast Holder: Comparison with Various...

Area of Science:

• Medical Physics
• Radiation Oncology

Background:

• Whole breast radiotherapy aims to protect normal organs, including the heart, while delivering effective treatment.
• Personalized breast holders (PERSBRA) offer a method for immobilizing the breast during radiotherapy.
• Evaluating the impact of PERSBRA on dose distribution, particularly skin surface dose, is crucial for optimizing treatment safety.

Purpose of the Study:

• To assess the skin surface dose in whole breast radiotherapy utilizing a personalized breast holder (PERSBRA).
• To compare the effects of different PERSBRA mesh sizes (large, fine, solid) on skin surface dose.
• To evaluate these effects across various radiotherapy techniques: hybrid, intensity-modulated radiotherapy (IMRT), and volumetric-modulated arc therapy (VMAT).

Main Methods:

• PERSBRA devices with three mesh sizes were designed and applied to an anthropomorphic phantom.
• Treatment plans were generated using hybrid, IMRT, and VMAT techniques for a total dose of 5000 cGy in 25 fractions.
• Dose measurements were performed using EBT3 film and thermoluminescent dosimeters (TLD) on the phantom with and without PERSBRA, analyzing tumor and surface doses.

Main Results:

• Tumor dose deviation remained within five percent across all measured techniques and configurations.
• The use of PERSBRA generally increased skin surface doses compared to no immobilization.
• A large mesh size PERSBRA demonstrated a reduction in skin surface dose compared to fine or solid mesh designs.

Conclusions:

• PERSBRA can reduce heart toxicity in breast radiotherapy but may increase skin surface dose.
• A larger mesh design for PERSBRA can help mitigate the build-up of skin surface doses.
• These findings are consistent across hybrid, IMRT, and VMAT radiotherapy techniques, offering guidance for clinical application.