The benefit of deep inspiration breath hold: evaluating cardiac radiation exposure in patients after mastectomy and after breast-conserving surgery

Background This study aims to evaluate the reduction of cardiac radiation dose and volume with deep inspiration breath hold (DIBH) technique compared to free breathing (FB) in patients with left-sided breast cancer. The study also aims to evaluate whether the benefits of DIBH vary in patients who had whole breast radiotherapy (RT) after breast-conserving surgery (BCS) and those who had chest wall RT post-mastectomy (M).