Late-Course Accelerated Hyperfractionated IMRT for Locoregionally Advanced Nasopharyngeal Carcinoma

Based on the radiobiological findings that accelerated tumor repopulation in nasopharyngeal carcinoma occurs in the late-course of radiation therapy, the investigators hypothesize that intensity-modulated radiation therapy(IMRT) with concomitant boost schedule by increasing daily dose starting at the fifth week after initiation of IMRT might improve tumor control and decrease treatment toxicities for locoregionally advanced nasopharyngeal carcinoma. The study is designed to test if late-course accelerated hyperfractionated IMRT can improve the outcomes as compared with conventionally fractionated IMRT in newly diagnosed patients with locoregionally advanced nasopharyngeal carcinoma.