A Multicenter, Randomized, Controlled Phase III Clinical Trial Comparing Ultra-Hypofractionated Versus Moderate Hypofractionated Radiotherapy for Regional Lymph Nodes in Post-operative Breast Cancer
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.
• Tumor stage is classified as T1, T2, or T3, as defined by the AJCC Cancer Staging Manual, 8th Edition.
• Meeting at least one of the following conditions:
∙ Pathological nodal status of pN2 or pN3a;
‣ Pathological nodal status of pN1 with one or more of the following high-risk factors:
• (I), Age \< 40 years. (II), Tumor location in the central or inner quadrant. (III), Estrogen Receptor (ER) negative. (IV), Presence of lymphovascular invasion (LVI). (V), Histological grade III. (VI), Patients presenting with clinical stage cN2-3a before neoadjuvant treatment.
• Pathologically negative surgical margins, defined as no ink on tumor.
• Karnofsky Performance Status (KPS) score ≥ 80.
• Documented biomarker status for Estrogen Receptor (ER), Progesterone Receptor (PR), HER2, and Ki-67.
⁃ Sufficient wound healing from surgery, with no signs of active infection at the intended radiation site.