What this Trial Is About

Researchers are investigating the role of postoperative regional nodal irradiation (RNI) in patients with intermediate-risk breast cancer, specifically those with T1-2N1 tumors. This phase III trial aims to determine whether RNI improves outcomes and to evaluate the safety and effectiveness of two radiotherapy schedules: 15-fraction hypofractionated and 5-fraction super-hypofractionated radiotherapy. Current recommendations support RNI for high-risk patients, but more evidence is needed for intermediate-risk cases. Participants will receive radiation to the chest wall or breast, with or without regional nodal irradiation. The study compares two radiotherapy regimens: a 15-fraction hypofractionated schedule and a 5-fraction super-hypofractionated schedule, which is a newer approach to shorten treatment duration. Treatments are delivered postoperatively following breast-conserving surgery or mastectomy with lymph node evaluation. During the study, participants will be monitored over an average of 10 years to assess disease-free survival. Researchers will track the effectiveness and toxicity of the radiotherapy treatments, as well as recurrence and safety outcomes. Follow-up evaluations will include clinical assessments to measure the long-term benefits and risks of the radiation approaches.

Hypofractionated Postoperative Regional Nodal Irradiation for Patients With Intermediate-risk Breast Cancer