For patients with breast cancer, regional nodal irradiation (RNI) can significantly reduce the risks of recurrence and mortality. Moderate hypofractionated regimens (40 to 42.5 Gy in 15 to 16 fractions over 3 weeks) is the established standard of care for RNI. Nevertheless, for the majority of patients, a three - week treatment duration is still regarded as lengthy. Although the ultra-hypofractionated regimen (26 Gy in 5 fractions over 1 week) has been proven non-inferior to the moderate hypofractionated regimen for whole breast irradiation, unambiguous evidence supporting its use in comprehensive RNI remains lacking, especially in high risk patients requiring internal mammary node irradiation (IMNI). This prospective, non-inferiority trial is designed to address this evidence gap by evaluating whether a one-week, ultra-hypofractionated regimen (26 Gy in 5 fractions) is non-inferior to the three-week regimen (40 Gy in 15 fractions) for comprehensive RNI, including IMNI.
Provide a signed and dated informed consent form (ICF) before the initiation of any trial-specific procedures.
Age ≥ 18 years.
Histologically confirmed invasive breast cancer.
Have received breast-conserving surgery or mastectomy with axillary staging, including sentinel lymph node biopsy, targeted axillary dissection and/or axillary lymph node dissection.
Nodal stage is classified as N3b or N3c, as defined by the AJCC Cancer Staging Manual, 8th Edition.
Has undergone or is planning immediate breast reconstruction with a permanent implant or tissue expander.
Evidence of distant metastatic disease.
Diagnosis of synchronous bilateral invasive breast cancer or a history of prior invasive cancer in either breast.