This study is a multicenter, randomized, phase 3 clinical trial. For breast cancer patients who underwent breast reconstruction after mastectomy, the hypofractionation radiotherapy group (experimental group) and the conventional fractionation radiotherapy group (control group) were divided 1:1 and compared to reveal the non-inferiority with hypofractionation in terms of major complication rate.~I. Primary Objective~To show the non-inferiority of major complication rate in reconstructed-breast between the hypofractionation radiotherapy group (experimental group) and the conventional fractionation radiotherapy group (control group) at 2 years after radiation therapy.~The main complications are defined at those requiring hospitalization or surgery among complications.~II. Secondary Objective:~Comparison of other side effects between the two groups.~Comparison of complication rate stratified by reconstruction timing and type of reconstruction~Immediate implant-based reconstruction~Immediate autologous reconstruction~Delayed-immediate implant reconstruction (2-stage)~Comparison of quality of life between the two groups.~Comparison of local and regional control rates between the two groups.~III. Tertiary Objective:~Comparison of cosmetic evaluations between the two groups.~Dosimetry analysis for correlation between the occurrence of complications and the dose profile.
This randomized Phase III study aims to show major complication rate of hypofractionation radiation therapy is not inferior, compared to conventional fractionation radiation therapy in breast cancer patients undergoing mastectomy and reconstruction surgery.