Abstract: Objective The aim of this study was to study the differences of survival time and side effects of five radiotherapy techniques for breast cancer patients after breast conserving surgery. Methods Two hundred patients with breast cancer who received breast conserving surgery in the department of Tumor Radiotherapy,the First Hospital of Qinhuangdao from January 1,2015 to January 1,2017 were selected and randomly divided into five groups with 40 patients in each group.The first group (3D-CRT group)selected 3D-CRT technology,the second group (ff-IMRT group)selected ff-IMRT technology,the third group (VMAT group)selected VMAT technology,the fourth group (CRT+IMRT Group)selected CRT+IMRT technology,and the fifth group (CRT+VMAT group)selected CRT+VMAT technology.After breast-conserving surgery,all patients in the group were followed up for more than 5 years.The curative effect and side effects of the patients were evaluated after follow-up,including local recurrence (LR),distant metastasis (DM),disease-free survival (DFS),and overall survival (OS).The evaluation of side effects included acute radiation pneumonia,acute radiation dermatitis,and late stage radiation induced cardiac injury. Results There was a statistical difference for the DM rate among the five groups of patients (P=0.005),and the DM rate in the CRT+VMAT group was lower than that in the other four groups.The median time (DFS,OS)of patients in the CRT+VMAT group was significantly higher than those of the other four groups (P＜0.001).The incidence of grade 0 acute radiation pneumonia in the CRT+IMRT group was lower than that in the VMAT group (P=0.048).The incidence of grade 2 acute radiation pneumonia in the CRT+VMAT group was lower than that in the ff-IMRT group (P=0.015).The incidence of grade 2 acute radiation dermatitis in the CRT+VMAT group was lower than that in the VMAT group (P=0.032).The incidence of grade 2 late radiation cardiac injury in the CRT+VMAT group was lower than that in the VMAT group (P=0.047). Conclusion The efficacy of CRT+VMAT technology is better than that of 3D-CRT,ff-IMRT,VMAT,CRT+IMRT,and the side effects of radiotherapy are lower than those of CRT,ff-IMRT,VMAT and CRT+IMRT.The CRT+VMAT techniques is worth popularizing in clinical practice.The CRT+VMAT technology is preferred for radiotherapy after breast conserving surgery for breast cancer patients.

Key words: Breast-conserving surgery for breast cancer, Radiotherapy technology, Curative effect