Investigators hypothesize that hypofractionated radiotherapy is equally effective and safe as conventional radiotherapy in breast cancer patients with an indication for regional nodal irradiation. Eligible breast cancer patients are randomized 1:1 into the following two groups: hypofractionated radiotherapy of 2.67 Gy for 16 fractions (and sequential tumor bed boost of 2.67 Gy for 4 fractions in patients with intact breast) and conventional radiotherapy of 2Gy for 25 fractions (and sequential tumor bed boost of 2 Gy for 5 fractions in patients with intact breast). The dose was prescribed to ipsilateral chest wall or whole breast and regional lymph regions (including supraclavicular and internal mammary lymph nodes). All patients are treated with IMRT. The primary endpoint is locoregional recurrence. Patients will be followed at least 5 years after radiotherapy to evaluated over survival, distant metastasis, toxicity and life quality.
The main objective of this trial is to investigate the efficacy and safety of hypofractionated radiotherapy of 3 or 4 weeks by comparing with conventional radiotherapy of 5 or 6 weeks using intensity-modulated radiation therapy (IMRT) in breast cancer patients with an indication for regional nodal irradiation (RNI) following mastectomy or breast conserving surgery. Patients will be randomized to hypofractionated radiotherapy or conventional radiotherapy delivered to chest wall or whole breast and regional lymph regions (including supraclavicular and internal mammary lymph nodes). Eligible breast cancer patients will be followed for at least 5 years to evaluate the difference in 5-year locoregional recurrence, over survival, distant metastasis, toxicity and life quality between two groups.