Objective:To compare the difference in dosimetric characteristics between 5 fsIMRT and 7 fIMRT after total mastectomy in mid-term cancer of the left breast.And to explore the difference between two intensity-modulated technologies in ameliorating target dose and protecting OARs after total resection of breast cancer.Methods:CT localization images of 60 patients with left breast cancer with radiotherapy were randomly selected from January to June 2017 and divided into two groups,the control group was designe...