Safety and Efficacy of IMPT or IMRT for Breast Cancer

Eligible breast cancer patients will receive either preoperative, postoperative, or definitive radiotherapy based on the MDT's recommendation. Patients with indications for treatment will receive either the IMPT or IMRT technique. The specific technique will be chosen based on the benefits of IMPT, patient preference, and reimbursement policies after discussion between the doctor and the patient. The primary endpoint is the occurrence of any acute radiation-induced toxicities of grade ≥2. Patients will be monitored for at least five years to evaluate acute and late radiation-induced toxicities, loco-regional recurrence, overall survival, distant metastasis, and quality of life.