Local regression and control of T1‐2 nasopharyngeal carcinoma treated with intensity‐modulated radiotherapy

OBJECTIVE: To observe the local regression and control in T1‐2 nasopharyngeal carcinoma (NPC) patients treated with intensity‐modulated radiotherapy (IMRT) and to analyze the related influencing factors. METHODS: Between January 2006 and June 2014, 247 consecutive T1‐2 NPC patients treated with IMRT were retrospectively analyzed, with 126 (51.0%) N0‐1 disease and 121 (49.0%) N2‐3 disease. Among them, 72.9% received platinum‐based chemotherapy. The prescribed dose to gross tumor volume was 66 Gy/30 fractions. RESULTS: By the end of IMRT, the chemoradiotherapy (CRT) group had higher local complete response (CR) rate compared with IMRT alone group (92.2% vs 74.6%, P < 0.001), but no significant difference was discovered in 5‐year local control (LC) rate (95.1% vs 94.9%, P = 0.968). Of the rest 31 patients with residual nasopharyngeal lesions after IMRT, those received boost irradiation (67.7%) also showed no improvement in 5‐year LC rate compared with the observational group (95.0% vs 100.0%, P = 0.307). With a median follow‐up of 63 months, the estimated 5‐year LC rate for the whole group was 95.1% (T1 vs T2: 95.9% vs 94.7%, P = 0.186). Prognostic factors for LC were found neither in univariate nor in multivariate analysis. Advanced N stage was found to be the only adverse prognostic factor for all the other survivals. CONCLUSIONS: Excellent LC could be achieved in T1‐2 NPC treated with IMRT. The addition of chemotherapy may offer short‐term response benefit, but no significant LC benefit, so did boost irradiation. Attention should be attached to advanced N stage, the exploration of the recurrence‐related factors, and the necessities of the additional treatment.