Improved heart, lung and target dose with deep inspiration breath hold in a large clinical series of breast cancer patients

Background and purpose: This study aims at evaluating the effect of deep-inspiration breath hold (DIBH) on target coverage and dose to organs at risk in a large series of breast cancer patients. Materials and methods: Clinical dose plans for 319 breast cancer patients were evaluated: 144 left-sided patients treated with DIBH and 175 free-breathing (FB) patients (83 left-sided and 92 right-sided). All patients received whole breast irradiation. with tangential fields, based on a forward-planned intensity-modulated radiation therapy (IMRT) technique. Dose to heart, ipsi-lateral lung and ipsi-lateral breast were assessed and median values compared between patient groups. Results: Comparing group median values, DIBH plans show large reductions of dose to the heart compared with left-sided FB plans; V-20Gy (relative volume receiving >= 20 Gy) for the heart is reduced from 7.8% to 2.3% (-70%, p < 0.0001), V-40Gy from 3.4% to 0.3% (-91%, p < 0.0001) and mean dose from 5.2 to 2.7 Gy (-48%, p < 0.0001). Lung dose also shows a small reduction in V-20Gy (P <0.04), while median target coverage is slightly improved (p = 0.0002). Conclusions: In a large series of clinical patients we find that implementation of DIBH in daily clinical practice results in reduced irradiation of heart and lung, without compromising target coverage. (C) 2012 Elsevier Ireland Ltd. All rights reserved. Radiotherapy and Oncology 106 (2013) 28-32