Clinical course of longer than five years after definitive radiotherapy for nasopharyngeal carcinoma.

Abstract

This study aimed to reveal the long-term outcomes and late toxicities (> 5years) after definitive intensity-modulated radiation therapy (IMRT) in patients with nasopharyngeal carcinoma (NPC). Data from 43 patients (median age, 55years; range, 17-72years) with NPC who underwent definitive IMRT between 2001 and 2018 were analyzed. All patients were alive and disease-free 5years after IMRT. A total dose of 70 (range, 66-70) Gy was delivered in 35 (33-35) fractions with concurrent cisplatin chemotherapy. The median follow-up duration was 119 (range, 61.5-242.1) months. Three patients developed locoregional failure at 79, 92, and 149months after IMRT, respectively. Of these, 2 patients died of disease progression at 136 and 153months after IMRT. One patient died of aspiration pneumonia 141months after IMRT, despite salvage of the recurrent tumor by re-irradiation. In addition, one patient died of aspiration pneumonia 62months after the IMRT. Thus, the 10-year overall survival, progression-free survival, and locoregional control rates were 98%, 92%, and 94%, respectively. Grade ≥ 2 and ≥ 3 late toxicities were observed in 28 (65%) and 9 (21%) patients, respectively. Nine second primary cancers, including five tongue cancers and two external auditory canal carcinomas, were observed in seven (16%) patients. Late recurrences, severe late toxicities, and second primary cancers were observed > 5years after IMRT. A long-term follow-up of > 5years is needed in patients with NPC.