ABSTRACT
Objective:To retrospectively analyze the long-term survival (10-15 years) and late toxicity of nasopharyngeal carcinoma (NPC) patients after intensity-modulated radiotherapy (IMRT), aiming to provide reference for the optimal treatment of NPC.Methods:132 patients with NPC who were treated with IMRT in Sichuan Cancer Hospital from 2003 to 2009 were recruited. Among them, 3 patients were classified as stage Ⅰ, 22 cases of grade Ⅱ, 61 cases of grade Ⅲ, 43 cases of Ⅳ A and 3 cases of Ⅳ B, respectively. The median dose was 73.37Gy (66 to 85Gy), divided into 33 times. Twenty patients received radiotherapy alone, 112 cases of concurrent radiochemotherapy. The survival rate was calculated by Kaplan-Meier method and log- rank test. Univariate prognostic analysis was performed. Cox model was used to conduct multivariate prognostic analysis. The late radiation toxicity was evaluated by RTOG/EORTC criteria. Results:The median follow-up duration was 128 months (range, 3 to 191 months). The 10-and 15-year local control rates of NPC patients were 86.0% and 79.9%. The disease-free survival rates were 72.5% and 63.2%, and the overall survival (OS) rates were 65.2% and 57.1%. The local recurrence rate was 12.1%, and the distant metastasis rate was 16.7%. A total of 53 patients died, of whom 15 patients died of local recurrence, 20 patients died of distant metastasis and 18 patients died of other diseases (pneumonia, intracranial hemorrhage and accident, etc.). The 10-and 15-year non-tumor-related mortality rates were 11.3% and 13.6%. Univariate analysis showed that age, smoking habit, lactate dehydrogenase (LDH), T stage and clinical stage were the independent prognostic factors of OS in NPC patients. Multivariate analysis demonstrated that LDH, T stage and synchronous chemotherapy were the prognostic factors of OS in NPC patients. The incidence of gradeⅠ-Ⅱ late radiation injury (hearing impairment, dysphagia, dental caries and xerostomia) was 90.4%, and 8.5% for grade Ⅲ-Ⅳ late radiation injury (skin fibrosis, hearing impairment and radiation brain injury).Conclusions:The 10-and 15-year OS of NPC patients treated with IMRT is relatively high. With the prolongation of survival, the non-tumor-related mortality rate is increased. Distant metastasis is the main cause of treatment failure. The main late injuries include grade Ⅰ/Ⅱ hearing impairment, dysphagia, dental caries and xerostomia.