Clinical Outcomes of Volume-Modulated Arc Therapy in 205 Patients with Nasopharyngeal Carcinoma: An Analysis of Survival and Treatment Toxicities

Background To investigate the clinical efficacy and treatment toxicity of volume-modulated arc therapy (VMAT) for nasopharyngeal carcinoma (NPC). Material and Methods 205 VMAT-treated NPC patients from our cancer center were prospectively entrolled. All patients received 68-70 Gy irradiation based on the planning target volume of the primary gross tumor volume. Acute and late toxicities were graded according to the Common Terminology Criteria for Adverse Events v3.0 and Radiation Therapy Oncology Group Late Radiation Morbidity Scoring Criteria. Results The median follow-up period was 37.3 months (range, 6.3-45.1 months). The 3-year estimated local failure-free survival, regional failure-free survival, locoregional failure-free survival, distant metastasis-free survival, disease-free survival and overall survival were 95.5%, 97.0%, 94.0%, 92.1%, 86.8% and 97.0%, respectively. Cox regression analysis showed primary gross tumor volume, N stage and EBV-DNA to be independent predictors of VMAT outcomes (P < 0.05). The most common acute and late side effects were grade 2-3 mucositis (78%) and xerostomia (83%, 61%, 34%, and 9% at 3, 6, 12 and 24 months after VMAT), respectively. Conclusions VMAT for the primary treatment of NPC achieved very high locoregional control with a favorable toxicity profile. The time-saving benefit of VMAT will enable more patients to receive precision radiotherapy.