Abstract:

Objective The aim of this study was to evaluate patterns of local or regional recurrence of nasopharyngeal carcinoma （NPC） in patients treated with intensity- modulated radiotherapy（IMRT）. Methods We performed a retrospective analysis of 645 patients with NPC treated at three centers in China from January 2009 to December 2011. All patients had non-metastatic NPC that had not been treated prior to IMRT. The Kaplan-Meier method was used to calculate patient survival rates，and log-rank testing was used to compare survival differences，and explore treatment failure patterns for local or regional recurrence after radiotherapy. Results During a mean follow-up of 62 months（11-95），local recurrence rates were 0.9% at 1 year，6.5% at 3 years，and 9.0% at 5 years. Locoregional control rates were 99.1% at 1 year，93.4% at 3 years，and 90.1% at 5 years. In the 60 patients with recurrence，in-field recurrence rate was 93.3% （56/60）；marginal-field recurrence，5.0% （3/60）；and out-field recurrence，1.7% （1/60）. Of all treatment failures，81.7%（49/60） occurred within the first three years after treatment. Conclusions IMRT resulted in excellent locoregional control in our NPC patients. Most cases of recurrence happened in the first three years after treatment. Locoregional failure most often involved in-field recurrence.

Key words: Nasopharyngeal neoplasms, Intensity-modulated radiotherapy, Local recurrence, Regional recurrence