近年来虽然放射治疗设备和技术有进一步提高 ,但鼻咽癌放疗的总体疗效没有明显提高 ,五年生存率仍徘徊在5 0 %— 6 0 % ,5年累积局部复发率达 2 0 %— 30 % [1 ] 。加速超分割是综合利用加速分割和超分割的特点 ,分割剂量较常规分割方式小 ,但比超分割方式分割剂量大 ,分割次数 Although the radiotherapy equipment and techniques have been further improved in recent years, the overall efficacy of radiotherapy for NPC has not been significantly improved. The five-year survival rate still hovers at 50% to 60% and the cumulative local recurrence rate at 20 years reaches 20% 30% [1]. Accelerated hyperfractionation is a comprehensive utilization of accelerated segmentation and hyperfractionation characteristics, segmentation dose than the conventional segmentation method, but compared with the super-segmentation method to split the dose, the number of segmentation