PURPOSE: Three boost radiotherapy (RT) techniques were compared to evaluate the dosimetric effect of seroma reduction during RT after breast-conserving surgery (BCS). MATERIALS AND METHODS: Twenty-one patients who developed seroma after BCS were included. Each patient underwent three CT scans: one week before RT (CT(-1)), in the third (CT(3)) and fifth (CT(5)) week of RT. For each patient, three plans were generated. (1) SEQ: whole breast irradiation planned on CT(-1,) sequential boost planned on CT(5), (2) SIB: simultaneous integrated boost planned on CT(-1), (3) SIB adaptive radiation therapy (SIB-ART): planned on CT(-1) and re-planned on CT(3). Irradiated volumes, mean lung (MLD) and maximum heart dose (HD(max)) were projected and compared on CT(5). RESULTS: On average 62% seroma reduction during RT was observed. Volumes receiving ≥ 107% of prescribed whole breast dose were significantly smaller with SIB-ART compared to SEQ and SIB. The undesired volume receiving ≥ 95% of prescribed total dose was also significantly smaller with SIB-ART. For SEQ, SIB-ART and SIB, respectively, small but significant differences were found in MLD (4.2 vs. 4.6 vs. 4.7 Gy) and in HD(max) for patients with left-sided breast cancer (39.9 vs. 35.8 vs. 36.9 Gy). CONCLUSIONS: This study demonstrates a dosimetric advantage for patients with seroma when simultaneous integrated boost is used with re-planning halfway through treatment.
PURPOSE: Three boost radiotherapy (RT) techniques were compared to evaluate the dosimetric effect of seroma reduction during RT after breast-conserving surgery (BCS). MATERIALS AND METHODS: Twenty-one patients who developed seroma after BCS were included. Each patient underwent three CT scans: one week before RT (CT(-1)), in the third (CT(3)) and fifth (CT(5)) week of RT. For each patient, three plans were generated. (1) SEQ: whole breast irradiation planned on CT(-1,) sequential boost planned on CT(5), (2) SIB: simultaneous integrated boost planned on CT(-1), (3) SIB adaptive radiation therapy (SIB-ART): planned on CT(-1) and re-planned on CT(3). Irradiated volumes, mean lung (MLD) and maximum heart dose (HD(max)) were projected and compared on CT(5). RESULTS: On average 62% seroma reduction during RT was observed. Volumes receiving ≥ 107% of prescribed whole breast dose were significantly smaller with SIB-ART compared to SEQ and SIB. The undesired volume receiving ≥ 95% of prescribed total dose was also significantly smaller with SIB-ART. For SEQ, SIB-ART and SIB, respectively, small but significant differences were found in MLD (4.2 vs. 4.6 vs. 4.7 Gy) and in HD(max) for patients with left-sided breast cancer (39.9 vs. 35.8 vs. 36.9 Gy). CONCLUSIONS: This study demonstrates a dosimetric advantage for patients with seroma when simultaneous integrated boost is used with re-planning halfway through treatment.
Authors: Tanja Alderliesten; Wilma D Heemsbergen; Anja Betgen; Rajko Topolnjak; Paula H M Elkhuizen; Corine van Vliet-Vroegindeweij; Peter Remeijer Journal: Phys Imaging Radiat Oncol Date: 2018-05-31