Risk Factors Of Radiation-induced Ulcer In Patients With Nasopharyngeal Carcinoma Treated With Volumetric Rotational Intensity Modulated Radiotherapy

OBJECTIVE:To analyse the clinical characteristics and prognosis of radiation nasopharyngeal ulcer after radiotherapy for nasopharyngeal carcinoma(VMAT)and explore The related risk factors of nasopharyngeal ulcer after VMAT radiotherapy.METHODS:We retrospectively analyzed 839 newly diagnosed nasopharyngeal carcinoma patients who underwent volume rotation intensity modulated radiotherapy(VMAT)in our radiotherapy center from January 2015 to March 2017.All patients were divided into ulcer and non-ulcer groups.Data analysis was performed by using chi-square test,Student t test,and binary logistic regression.All statistical tests were two-sided and p< 0.05 was considered statistically significant.RESULTS:In this study,839 patients who were newly diagnosed nasopharyngeal carcinoma were divided into ulcer group(46 cases)and non-ulcer group(793 cases).The general clinical characteristics(gender,age,tumor stage,complications),nutritional status(BMI,hemoglobin,albumin,and prealbumin),treatment options(radiotherapy,chemotherapy,nimotuzumab,and sodium glycididazole),nasopharyngeal lesions and follow-up data of the two groups were analyzed.Univariate analysis showed that age,T stage,number of induction chemotherapy cycles,albumin after radiotherapy,prealbumin after radiotherapy,acute mucosal response,and volume of PTVnx were significantly associated with the occurrence of nasopharyngeal ulcer(P<0.05).Multivariate analysis of risk factors for all P values <0.05 revealed that older age,late T stage,fewer induction chemotherapy cycles,low albumin after radiotherapy,severe mucosal response,and larger volume of PTVnx were independent risk factorsj for VMAT nasopharyngeal ulceration.CONCLUSIONS:Older age,late T stage,fewer induction chemotherapy cycles,poor nutritional status after radiotherapy,severe mucosal response,and larger PTVnx volume are independent risk factors for VMAT nasopharyngeal ulceration.