Impact of Deep Inspiration Breath Hold Technique on Cardiac and Pulmonary Dose in Patients Undergoing Left Breast Radiotherapy

The role of radiotherapy in left breast cancer primarily aims to treat the breast while limiting the dose to adjacent organs in the irradiated area, such as the heart, lungs, and anterior descending artery, seeking to ensure the patient's quality of life by minimizing the probability of future damage to these organs. This study aims to evaluate the reduction in cardiac and pulmonary dose when using the deep inspiration breath-hold (DIBH) technique compared to traditional free-breathing (FB) treatment. Dosimetric data were collected from 64 patients who underwent left breast cancer treatment from 2021 to 2023. The cases were planned using three-dimensional conformal radiotherapy on the Eclipse v15.6 planning system, with photon beams from a TrueBeam Stx linear accelerator, employing tangential fields. The prescription was for moderate hypofractionation with sequential or concurrent boost. All selected patients had undergone planning computed tomography (CT) scans in FB and DIBH, with planning conducted for both image acquisitions. Plans were developed to ensure no significant difference in target coverage between both CT scans. The mean dose to the heart showed an average reduction of 46.13% (±18.06%), while the left anterior descending artery (LAD) exhibited an average reduction of 65.86% (±22.21%) in mean dose. No significant differences were found in the dose to the left lung.