Objective:To investigate the efficacy and toxicity of hypofractionation radiotherapy in patients with breast cancer after postmastectomy. Methods:A total of 85 postmastectomy with breast cancer after postmastectomy were included,treated by ipsilateral chest wall and supraclavicular nodal radiation. 41 patients received to 42. 56 Gy /16 f,22- 24 days(HF group),44 patients received to 50 Gy /25 f,33- 35 days(CF group). The incidence of local control,distant metastasis and acute radiation toxicity were evaluat...