Ultra-Hypofractionated vs Moderate Hypofractionated Radiotherapy for Regional Lymph Nodes in High Risk 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.

NCT Number	NCT07527689
Lead Sponsor	Ruijin Hospital
Conditions	Breast Cancer
Enrollment	1,950 participants
Start Date	2026-04-22
Primary Completion	2034-03-30 (estimated)
Study Completion	2039-03-30 (estimated)
Updated on ClinicalTrials.gov	2026-06-30