Comparison Of Efficacy And Safety Of Hypofractionated Fractionation And Conventional Fractionation Radiotherapy After Breast Conserving Surgery For Early Breast Cancer

Objective:To compare the clinical efficacy and safety of hypofractionated radiotherapy and conventional fraction radiotherapy after breast conserving surgery for early breast cancer,and to provide the optimal choice of radiotherapy for patients after breast conserving surgery for early breast cancer.Methods:Seventy-eight patients with early breast cancer after breast-conserving surgery admitted to our hospital from June 2018 to June 2021 were selected.The dose of hypofractionated radiotherapy group（n = 39）: whole breast irradiation PTV43.5Gy/2.9Gy/15 f,tumor bed synchronous supplement PTV-tb 49.5Gy/3.3Gy/15 f.Conventional segmentation group（n=39）dose: PTV50Gy/2.0Gy/25 f tumor bed sequential supplement10Gy/5f.Clinical efficacy（local control rate,distant metastasis rate and 1-year survival rate）,early and late adverse reactions,cosmetic effects,length of hospital stay and treatment costs in 2 groups were observed.Early and late adverse reactions were evaluated according to RTOG standard,cosmetic effect was evaluated according to Harris standard,and statistical analysis was performed using SPSS（22.0）software.Results:1.The baseline characteristics of the hypofractionated radiotherapy group and the conventional group were basically the same.2.Clinical efficacy:the 1-year survival rate and local control rate were 100% in both groups.The distant metastasis rate was 0% in the hypofractionated radiotherapy group,and the distant metastasis rate was 2.56% in the conventional radiotherapy group.3.Acute hematologic toxicity: There was no grade 3 or above hematologic toxicity in the two groups.The total incidence of grade 1 and 2 leukopenia,thrombocytopenia and neutropenia in the large segmentation group was 51.28%,7.69%and 43.59%,respectively.The total incidence of grade 1 and 2 leukopenia,thrombocytopenia and neutropenia was 43.59%,10.25% and 30.77% in the conventional radiotherapy group.There was no significant difference between the two groups（P> 0.05）.4.Acute radioactive dermatitis: the total incidence of grade 1 and 2 radioactive dermatitis in the hypofractionated radiotherapy group and the conventional radiotherapy group was 92.3% and 94.9%,respectively,without grade 3 or above severe early skin reaction,showing no difference between the two groups（P=0.619）.5.Radiation pneumonia: there was no radiation pneumonia in the hypofractionated radiotherapy group,while the incidence of radiation pneumonia in the conventional radiotherapy group was 2.56%（1/39）.Excluding possible risk factors,there was no statistical significance between the two groups（P>0.05）.6.Late adverse reactions: hypofractionated radiotherapy group,16 patients（41.03%）showed late adverse reactions,10 patients（25.7%）showed skin and subcutaneous adverse reactions（pigmentation,fibrosis,sclerosis in tumor bed area）,4patients（10.3%）showed breast shrinkage,and 2 patients（5.1%）showed breast edema.In the conventional radiotherapy group,17 patients（43.59%）showed late adverse reactions,8 patients（20.5%）showed skin and subcutaneous tissue adverse reactions,6 patients（15.4%）showed breast shrinkage,and 3 patients（7.7%）showed breast edema.7.Cosmetic effect: Excellent and good rate of the segmentation group was 100%at 1 month after radiotherapy;Conventional radiotherapy group was 97.4%.At 6months after radiotherapy,the excellent and good rate of the segmented group was97.4%.Conventional radiotherapy group was 94.9%.The cosmetic scores of the two groups at 1 and 6 months after radiotherapy were basically the same,and there was no statistical difference（P> 0.05）.8.Length of hospital stay and treatment cost: average length of hospital stay in hypofractionated radiotherapy group was 22（21～24）days,and treatment cost was（43610.64±4445.22）Yuan;The average hospital stay in the conventional radiotherapy group was 43（42～44）days,and the treatment cost was（50015.97±3948.95）Yuan.The length of hospital stay was reduced by about 3 weeks and treatment costs were lower in the hypofractionated radiotherapy group compared with the conventional radiotherapy group.Conclusions:1.Compared with conventional radiotherapy,hypofractionated radiotherapy has the same local control and cosmetic effect,and does not increase early and late adverse reactions.2.Hypofractionated radiotherapy can shorten the total treatment time and treatment cost,reduce the exposure risk of patients and medical staff,and improve postoperative radiotherapy compliance of patients with early breast cancer.