Eligible patients after breast conserving surgery will be randomized 1:1 into hypofractionated radiotherapy (HF-RT) group or conventionally fractionated radiotherapy (CF-RT) group.~Patients in HF-RT group will receive 40 Gy/15 fractions irradiation to the whole breast with/without regional lymphnodes within 3 weeks and the tumor bed is boosted to 48 Gy/15 fractions simutaneously.~Patients in CF-RT group will receive 50 Gy/ 25 fractions irradiation to whole breast with/without regional lymphnodes within 5 weeks and the tumor bed is boosted to 60 Gy/30 fractions sequentially.~The primary endpoint is loco-regional recurrence. Other cancer related events and acute/late radiation morbidities will also be evaluated. The patients will be followed for 10 years.~It is hypothesized that hypofractionated radiotherapy is non inferior to conventional fractionated radiotherapy in terms of tumor loco-regional control for patients after breast conserving surgery.
The study was designed to investigate whether hypofractionated radiotherapy(HF-RT) is noninferior to conventionally fractionated radiotherapy (CF-RT) in terms of tumor loco-regional control for patients after breast conserving surgery