Analysis Of Risk Factors Of Nasopharyngeal Necrosis After VMAT Radiotherapy In Newly Diagnosed Stage M0 Nasopharyngeal Carcinoma

Background and Objective:Nasopharyngeal necrosis is one of the serious sequelae of nasopharyngeal carcinoma after radiotherapy,which seriously affects the quality of life and even endangers the lives of patients.The purpose of this study was to analyze the risk factors of nasopharyngeal necrosis after VMAT radiotherapy for newly diagnosed stage M0 nasopharyngeal carcinoma.Methods:The related data of newly diagnosed nasopharyngeal carcinoma patients without distant metastasis treated with VMAT radiotherapy in Jiangxi Cancer Hospital from December 1,2016 to March 31,2021 were analyzed retrospectively.Univariate and multivariate Logistic regression analysis were performed to determine the indepen-dent risk factors of nasopharyngeal necrosis after VMAT radiotherapy for nasopharyngeal carcinoma.Results:Among the 506 patients in the group,38 patients developed nasopharyngeal necrosis,the necrosis rate was 7.5%,and the median time of nasopharyngeal necrosis was 4.43 months.In univariate analysis,T stage,total clinical stage,nasopharyngeal pseudomembrane formation,V-GTVnx,V-PTVnx,V105,hemoglobin after radiothe-rapy and weight loss after radiotherapy were the risk factors of nasophary-ngeal necrosis after radiotherapy.Multivariate analysis showed that pseudomembrane(OR= 7.003,95%CI:2.0675-23.722,P=0.002),hemoglobin after radiotherapy(OR=0.388,95%CI:0.161-0.935,P=0.035)and weight loss after radiotherapy(OR=3.784,95% CI:1.563-19.157,P=0.003)were independent risk factors for nasopharyngeal necrosis after VMAT radiotherapy.Conclusion:Nasopharyngeal pseudomembrane formation,decreased hemoglobin after radiotherapy and weight loss after radiotherapy significantly increased the risk of nasopharyngeal necrosis after VMAT radiotherapy for newly diagnosed stage M0 nasopharyngeal carcinoma.