Deep inspiration breath-hold radiation therapy in left-sided breast cancer patients: a single-institution retrospective dosimetric analysis of organs at risk doses

Abstract

Background Radiotherapy can induce cardiac injury in left-sided breast cancer cases. Cardiac-sparing irradiation using the deep inspiration breath-hold (DIBH) technique can achieve substantial dose reduction to vulnerable cardiac substructures compared with free breathing (FB). This study evaluated the dosimetric differences between both techniques at a single institution. Methods From 2017 to 2019, 130 patients with left-sided breast cancer underwent breast-conserving surgery (BCS; n = 121, 93.1%) or mastectomy (ME; n = 9, 6.9%) along with axillary lymph node staging (n = 105, 80.8%), followed by adjuvant irradiation in DIBH technique; adjuvant systemic therapy was included if applicable. 106 (81.5%) patients received conventional and 24 (18.5%) hypofractionated irradiation. Additionally, 12 patients received regional nodal irradiation. Computed tomography (CT) scans in FB and DIBH position were performed for all patients. Intrafractional 3D position monitoring of the patient surface in deep inspiration and breath gating was performed using Sentinel and Catalyst HD 3D surface scanning systems (C-RAD, Catalyst, C‑RAD AB, Uppsala, Sweden). Individual coaching and determination of breathing amplitude during the radiation planning CT was performed. Three-dimensional treatment planning was performed using standard tangential treatment portals (6 or 18 MV). The delineation of cardiac structures and both lungs was done in both the FB and the DIBH scan. Results All dosimetric parameters for cardiac structures were significantly reduced (p < 0.01 for all). The mean heart dose (Dmean) in the DIBH group was 1.3 Gy (range 0.5–3.6) vs. 2.2 Gy (range 0.9–8.8) in the FB group (p < 0.001). The Dmean for the left ventricle (LV) in DIBH was 1.5 Gy (range 0.6–4.5), as compared to 2.8 Gy (1.1–9.5) with FB (p < 0.001). The parameters for LV (V10 Gy, V15 Gy, V20 Gy, V23 Gy, V25 Gy, V30 Gy) were reduced by about 100% (p < 0.001). The LAD Dmean in the DIBH group was 4.1 Gy (range 1.2–33.3) and 14.3 Gy (range 2.4–37.5) in the FB group (p < 0.001). The median values for LAD such as V15 Gy, V20 Gy, V25 Gy, V30 Gy, and V40 Gy decreased by roughly 100% (p < 0.001). An increasing volume of left lung in the DIBH position resulted in dose sparing of cardiac structures. Conclusion For all ascertained dosimetric parameters, a significant dose reduction could be achieved in DIBH technique.

Impact of deep inspiration breath hold irradiation on dose reduction to the heart and left coronary artery in breast cancer

“…However, this effect was not as unequivocal as with the heart and the LAD, and it should be kept in mind that in a significant group of patients, DIBH plans were inferior to the FB technique in terms of the MLD and V20Gy. Some recent studies with significant groups of patients show similar results [5,[26][27][28]. In some patients with special concerns about lung toxicity, when DIBH is not sufficient to reduce the dose to the heart and the ipsilateral lung, radiotherapy in the prone position is a promising option [5].…”

Acute adverse events of ultra-hypofractionated whole-breast irradiation after breast-conserving surgery for early breast cancer in Japan: an interim analysis of the multi-institutional phase II UPBEAT study

“…For spatial localization during each treatment, megavoltage electronic portal imaging or a similar imaging system was used. During the simulation process and each treatment session for patients with cancers of the left breast, deep inspiration breath-holding was recommended to reduce the dose delivered to the heart [ 15 , 16 ]; however, this was not essential, and free breathing was permitted in all cases.…”

Acute adverse events of ultra-hypofractionated whole-breast irradiation after breast-conserving surgery for early breast cancer in Japan: an interim analysis of the multi-institutional phase II UPBEAT study

“…For spatial localization during each treatment, megavoltage electronic portal imaging or a similar imaging system was used. During the simulation process and each treatment session for patients with cancers of the left breast, deep inspiration breath-holding was recommended to reduce the dose delivered to the heart [15,16]; however, this was not essential, and free breathing was permitted in all cases.…”