鼻咽癌IMRT再计划的研究进展

Research progress in replanning during intensity-modulated radiotherapy for nasopharyngeal carcinoma

IMRT是目前鼻咽癌最主要的治疗手段。研究表明鼻咽癌放疔过程中由于原发肿瘤及转移淋巴结退缩、体重下降导致正常器官及头颈部轮廓缩小，这些变化可能引起原发肿瘤剂量不足和OAR剂量过高，从而影响治疗疗效。放疗中修改计划可保证靶区剂量、降低OAR剂量，部分患者从中获益。但对于IMRT中再计划的优势、时机及频率还未达成共识，需要继续探索。对于如何挑选放疗中需要修改计划的患者目前缺乏相应的规范，有待继续研究。

Intensity-modulated radiotherapy （IMRT） is the first-line treatment for nasopharyngeal carcinoma currently. Previous studies have shown that regression of primary tumor and metastatic lymph nodes or a decrease in body weight causes the contour of normal organs and head-and-neck to shrink during the course of radiotherapy, which may lead to underdose in primary tumor and overdose in organs at risk （OARs） and then adversely affect treatment outcomes. Replanning during the course of radiotherapy can maintain the dose to target volume and reduce the exposure of OARs, which improves outcomes in some patients. For replanning during the course of IMRT, however, the advantages have not been widely recognized and there is still a long way to go before widely accepted timing and frequency of replanning are set up. Further studies are needed to figure out how to identify patients appropriate for plan modification.