Abstract
Breast radiotherapy, typically administered using tangential fields in the supine position, employs various strategies to improve dose uniformity and minimize radiation exposure to sensitive organs. However, managing patients with large or pendulous breasts presents technical challenges, leading to the investigation of prone position radiotherapy, which has shown benefits in reducing skin reactions and lung radiation dose. Herein, we present a technical note detailing the implementation of a customized Vac-Lok prone pillow setup for adjuvant radiotherapy in a patient with extremely large pendulous breasts. The use of polystyrene foam slabs of 7 cm each and a Vac-Lok over it with a groove to place the ipsilateral breast hanging down and away from the midline and arms extended overhead on a customized prone pillow, enabled a comfortable position for the patient. Compared to the plan generated in the supine position, the prone plan showed a significant reduction in radiation dose to the ipsilateral lung.