Deep inspiration breath-hold (DIBH) radiotherapy in left-sided breast cancer: Dosimetrical comparison and clinical feasibility in 20 patients

Background Adjuvant radiotherapy after breast-conserving surgery (BCS) for breast cancer (BC) is a well-established indication. The risk of ischaemic heart disease after radiotherapy for BC increases linearly with the heart mean dose with no apparent threshold. Radiotherapy to the left breast in deep inspiration breath-hold (DIBH) reduces the dose to the heart. A new linac system with an integrated surface scanner (SS) for DIBH treatments was recently installed in our department. We tested it for potential benefits, safety, patients’ acceptance/compliance and associated additional workload. Materials and methods Twenty consecutive patients following BCS for breast carcinoma of the left side were enrolled in our institutional DIBH protocol. We compared dose to the heart and ipsilateral lung (IL) between plans in DIBH and free breathing (FB) using standard defined parameters: mean dose, maximal dose to a volume of 2 cm 3 (D 2 cm 3 ), volume receiving ≥ 5 Gy (V 5 ), 10 Gy (V 10 ), 15 Gy (V 15 ) and 20 Gy (V 20 ). Comparison of median calculated dose values was performed using a two-tailed Wilcoxon signed rank test. Results DIBH was associated with a statistically significant reduction ( p