Eligible breast cancer patients will receive hypofractionated radiotherapy of 5.2 Gy in 5 fractions within one week and a sequential tumor bed boost of 5.2 Gy in 2 fractions to the conserved breast. The dose is prescribed to ipsilateral chest wall or whole breast and regional lymph regions (including supraclavicular/infraclavicular region, internal mammary nodes, and any part of the axillary bed at risk). All patients are treated with intensity modulated radiation therapy (IMRT) technique. The primary endpoint is ≥2 grade any acute radiation induced toxicity event. patients will be followed for at least 1 years to evaluate the acute and late radiation-induced toxicity, locoregional recurrence, over survival, distant metastasis, and quality of life.~Calculation of the required number of cases based on an alpha of 0.05 and a power of 80% with a maximal tolerable toxicity difference of 10% during and within 6 months after RNI comparing to conventional radiotherapy and lost rate of follow up of 10%. In total 197 patients are needed to be recruited.
The purpose of this trial is to investigate the toxicities and efficacy of hypofractionated regional nodal radiotherapy (RNI) for one week in breast cancer patients treated with mastectomy or breast conserving surgery. Hypofractionated radiotherapy will be delivered to chest wall or whole breast and regional lymph regions (including supraclavicular/infraclavicular region, internal mammary nodes, and any part of the axillary bed at risk). Eligible breast cancer patients will be followed for at least 1 years to evaluate the acute and late radiation-induced toxicities, locoregional recurrence, over survival, distant metastasis, and quality of life.