Hypofractionated versus conventional fractionated radiotherapy for breast cancer in patients with reconstructed breast: Toxicity analysis

PURPOSE: This study investigated whether hypofractionated adjuvant radiotherapy (RT) increased breast-related complication(s) compared to conventional fractionated RT in reconstructed breast cancer patients. METHODS: We conducted a retrospective review including 349 breast cancer patients who underwent immediate breast reconstruction following mastectomy or breast-conserving surgery (BCS) between 2009 and 2018 at two institutions. All patients were treated with adjuvant RT via either a conventional fractionated or hypofractionated regimen. We defined a major breast complication as a breast-related toxic event requiring re-operation or re-hospitalization during the follow-up period after the end of RT. RESULTS: The median follow-up was 32.3 months (4.8–118.5 months); 126 patients had conventional fractionated RT, and 223 patients received hypofractionated RT. In patients with mastectomy, there was no significant difference in the occurrence of any or major breast-related complications between the two fractionation regimens. In patients undergoing BCS, incidence of any breast complication showed no difference between two RT groups and no major breast complication was reported as well. Hypofractionated RT did not increase major wound problem (infection and dehiscence) compared to conventional RT. Incidence of major contracture was significantly lower in hypofractionated RT. CONCLUSIONS: There was no significant difference in the occurrence of any or major breast-related complications between the two different fractionation regimens, even in patients with mastectomy. Hypofractionated RT may be used comparable to conventional fractionated RT in terms of breast-related complications in reconstructed breast cancer patients. The prospective randomized trial would be necessary to clarify this issue.