Failure patterns and survival in patients with nasopharyngeal carcinoma treated with intensity modulated radiation in Northwest China: A pilot study

PURPOSE: To evaluate the clinical outcomes and patterns of failure in patients with nasopharyngeal carcinoma (NPC) treated with intensity modulated radiotherapy (IMRT) in Northwest China. METHODS AND MATERIALS: From January 2006 to December 2009, 138 NPC patients were treated at Xijing Hospital. Of them, 25 cases with stage I-II received IMRT only, 113 cases with stage III-IVb received IMRT plus accomplished platinum-based chemotherapy. The IMRT prescribed dose was PTV 68-74 Gy to gross disease in nasopharynx and 66-72 Gy to positive lymph nodes in 30-33 fractions, and high risk and low risk region PTV was 60-63 Gy and 50.4~56 Gy in 30~33 and 28 fractions respectively. Plasma Epstein Barr virus (EBV) DNA load was measured before treatment. The clinical toxicities, outcomes and patterns of failure were observed. RESULTS: The median follow up time was 23 months (range 2 to 53 months). EBV infection positive was only 15.9%. Overall disease failure developed in 36 patients, 99% belonged to stage III/IV disease. Among these, there were 26 distant metastases, 6 local recurrence, and 4 regional recurrence. The 3-year local control rate(LCR), distant metastasis-free survival (MFS), disease-free survival (DFS) and the overall survival (OS) was 93.9%, 79.5%, 70% and 83.1% respectively. Multivariate analyses revealed that age and anemia pre-radiotherapy were independent predictors for OS. CONCLUSION: IMRT with or without chemotherapy can improve the long term survival of NPC patients in Northwest China. Distant metastasis becomes the main cause of treatment failure. Age and anemia before radiotherapy were the main prognosis factors of NPC patients.