Influence of Hypofractionated versus Conventional Fractionated Postmastectomy Radiotherapy in Breast Cancer Patients with Reconstruction.

Abstract Purpose We aimed to compare breast-related complication(s) between hypofractionated adjuvant postmastectomy radiotherapy (PMRT) and conventional fractionated RT in reconstructed breast cancer patients according to reconstruction surgery type. Methods A total of 396 breast cancer patients who underwent breast reconstruction following mastectomy between 2009 and 2018 were retrospectively reviewed. All the patients received the adjuvant PMRT via either a conventional fractionation or hypofractionation schedule. We analyzed breast-related complications according to the timing of breast reconstruction (immediate or delayed). In cases of delayed reconstruction, only PMRT delivered before final delayed reconstruction was included. A major breast complication was defined as a breast-related toxicity requiring re-operation or re-hospitalization after the end of RT. Results The median follow-up time was 35.3 months (8.8–122.7 months). Of all patients, 267 received immediate breast reconstruction and 129 received delayed breast reconstruction. In patients with immediate breast reconstruction, 91 were treated with conventional RT and 176 received hypofractionated RT. The occurrence of major breast-related complications did not differ significantly between the two fractionation regimens. Hypofractionated RT did not increase major wound problems (infection and dehiscence) compared to conventional RT. Further, major contracture occurred significantly less frequently in hypofractionated RT. Of the patients who had delayed breast reconstruction, 48 received conventional RT and 81 received hypofractionated RT. There was no difference between the incidence of major breast complications between these two RT groups and no difference in major breast complications were reported for either one- or two- stage delayed reconstruction. A time interval of more than 10 months between PMRT and final definitive reconstruction had a significantly lower incidence of major breast complications. Conclusions Hypofractionated RT appears to be comparable to conventional fractionated RT in terms of breast-related complications in reconstructed breast cancer patients, regardless of breast reconstruction type. An ongoing prospective randomized trial should confirm our findings.