Clinical Outcome Of Intraoperative Radiotherapy Versus Postoperative Whole-breast Radiotherapy For Patients With Invasive Breast Cancer:A Meta-analysis

Objective: At present,with the diversification of treatments for breast cancer,The number of patients with invasive breast cancer undergoing breast-conserving surgery is gradually increasing,but they often need to receive whole-breast radiotherapy for 4-6 weeks after operation,which increases the economic burden of patients and radiation complications such as cardiotoxicity and lung injury.The technique of intraoperative radiotherapy is a single intraoperative radiotherapy instead of postoperative whole breast radiotherapy to reduce the economic burden of patients and reduce the radiation complications such as cardiotoxicity and lung injury caused by radiotherapy.However,the application of intraoperative radiotherapy is still under study,it is not clear whether intraoperative radiotherapy can replace postoperative whole breast radiotherapy.In this study,through a meta-analysis of the published studies on intraoperative radiotherapy,to evaluate the application value of intraoperative radiotherapy in breast-conserving surgery,and to provide more radiotherapy decisions for breast-conserving patients with invasive breast cancer.Methods: Two authors conducted literature search through Chinese and English databases such as CNKI?Wanfang?Pubmed?Embase etc,and searched the relevant studies published before October 30,2019 on intraoperative radiotherapy techniques in breast-conserving surgery for invasive breast cancer.The relevant literatures were selected strictly according to the set inclusion criteria and exclusion criteria,and the relevant data were extracted for integrated analysis.We used the PEDro scale to score the literature quality of randomized controlled trials,and the MINORS scale to score the literature quality of non-randomized controlled trials.We used Review Manager 5.3 to extract data from the included literatures,use random effect model to analyze the included literatures by meta and draw forest map.We conducted subgroup analysis according to randomized controlled trials and non-randomized controlled trials,and use Stata13.0 for sensitivity analysis.Results: A total of 12 literatures were included.there were 3 RCT studies and 9 non-RCT studies,including 6659 cases,including 4941 cases in the RCT group(IORT group: 2463 cases,WBRT group: 2478 cases)and 1718 cases in the non-RCT group(IORT group: 2463 cases,WBRT group: 1011 cases).The results show: the ipsilateral local recurrence rate of invasive breast cancer patients treated with breast conserving surgery(BCS)and Intraoperative Radiation Treatment(IORT)group was higher than that of postoperative whole breast radiotherapy(WBRT)group(RR:2.22,95% CI:1.33~3.73);The distant metastasis rate of breastconserving intraoperative radiotherapy(IORT)and postoperative whole-breast radiotherapy(WBRT)in patients with invasive breast cancer were lower,and there was no significant difference between them(RR:0.88,95%CI: 0.58~1.33).There was no significant difference in breast cancer specific mortality between breast-conserving intraoperative radiotherapy(IORT)and postoperative whole-breast radiotherapy(WBRT)for invasive breast cancer(RR:1.16,95% CI:0.77~1.76).The non-breast cancer mortality in the intraoperative radiotherapy(IORT)for invasive breast cancer after breast-conserving surgery is lower than that of the postoperative whole-breast radiotherapy(WBRT)(0.8%vs1.2%),but there is no significant difference(RR:0.70,95%CI:0.38~1.30).There was no significant difference in the overall mortality between breast-conserving intraoperative radiotherapy and postoperative whole-breast radiotherapy(WBRT)for invasive breast cancer(RR:0.84,95%CI:0.63~1.11).Compared with postoperative whole-breast radiotherapy(WBRT),the incidence of skin toxic reactions is significantly lower in breast-conserving intraoperative radiotherapy(IORT)(RR:0.33.95%CI:0.19~0.58),The incident rate of poor cosmetic effect after intraoperative radiotherapy(IORT)is lower(RR:0.57,95%CI:0.37~0.89).Conclusions: 1.The long-term survival benefit of intraoperative radiotherapy(IORT)is not lower than that of postoperative whole breast radiotherapy(WBRT).2.The risk of local recurrence of intraoperative radiotherapy(IORT)is higher than postoperative whole breast radiotherapy(WBRT),so the objects of intraoperative radiotherapy(IORT)should be selected carefully,patients with low risk of local recurrence should be selected as far as possible(age?50?Pathological tumour size?2.0cm?Axillary lymph node negative?resected with margins negative at?2mm?Estrogen receptor positive).3.Compared with postoperative whole-breast radiotherapy(WBRT),Intraoperative radiotherapy(IORT)has lower skin toxicity and better cosmetic effect.