Dosimetric and clinical factors for predicting acute radiation oral mucositis in locally advanced nasopharyngeal carcinoma patients treated with intensity-modulated radiotherapy with concurrent chemotherapy

Abstract

Objective To prospectively determine the dosimetric and clinical factors for predicting the risk of acute radiation oral mucositis (ROM) in patients receiving intensity-modulated radiotherapy (IMRT) with concurrent chemotherapy for local advanced nasopharyngeal carcinoma. Methods Ninety-two patients who were treated with IMRT with concurrent chemotherapy from 2015 to 2016 for local advanced nasopharyngeal carcinoma were included in this study, and their acute ROM was scored according to the RTOG criteria. Grade ≥3 ROM was used as a surrogate marker for severe mucositis, which was defined as a toxicity endpoint. The clinical data were reviewed, and the dose-volume histograms (DVHs) of the patients were exported from the IMRT planning system. Optimal thresholds for predicting the incidence of severe ROM were evaluated by the area under the receiver operating characteristic (ROC) curve (AUC). Results The incidence of severe ROM was 21%(19/92). Weight loss and V30 of the oral mucosa were determined as the independent predictors for severe ROM (P=0.017 and 0.003, respectively). The optimal cut-off point and AUC of V30 of the oral mucosa as a predictor for severe ROM were 73.16%(0.842 sensitivity and 0.671 specificity) and 0.753(P=0.001), respectively. Conclusion Weight loss and V30 of the oral mucosa are predictors for severe ROM. Key words: Nasopharyngeal neoplasms/chemoradiotherapy; Radiotherapy, intensity modulated; Radiation oral mucositis; Dose volume histogram