T_2期鼻咽癌旋转调强与固定野动态调强计划的剂量学比较研究  

Dosimetric Comparison of Intensity-modulated Arc Radiotherapy and Fixed Beam Dynamic Intensity-modulated Radiation Therapy in Stage T_2 Nasopharyngeal Carcinoma

作　　者：廖雄飞[1] 黎杰[1] 谭志博[1] 陈亚正[1] 王培[1] 

机构地区：[1]四川省肿瘤医院放疗科,成都610041

出　　处：《肿瘤预防与治疗》2014年第3期115-119,共5页Journal of Cancer Control And Treatment

摘　　要：目的:比较旋转调强(intensity-modulated arc radiotherapy,IMAT)与固定野动态调强(dynamic intensitymodulated radiation therapy,dIMRT)在T2期鼻咽癌放射治疗计划中的剂量学差异。方法:随机选取10例已经接受固定野动态调强放射治疗的T2期鼻咽癌病例,将这10例放疗计划改为旋转调强方式,重新进行计划优化,比较两种计划的等剂量分布、靶区和危机器官的剂量参数、机器跳数以及治疗时间等。结果:两种计划的靶区剂量分布D98、D95以及D2等参数均无统计学差异(P>0.05),IMAT计划的脑干Dmax和D1cc、脊髓Dmax、右腮腺Dmean、右颞颌关节Dmax以及左中耳Dmean和Dmax均明显小于dIMRT计划的受量(P<0.05);同时IMAT计划的左右晶体Dmax、左右视神经Dmax和视交叉Dmax均明显大于dIMRT计划的受量(P<0.05)。IMAT计划正常组织受照剂量为5Gy的总体积明显大于dIMRT计划(P<0.05),而受照剂量在20Gy和30Gy的总体积明显小于dIMRT计划(P<0.05)。IMAT比dIMRT计划的单次照射总机器跳数平均减少了47.0%,单次照射时间平均减少48.2%。结论:对于T2期鼻咽癌,两种计划的剂量分布均满足临床要求,在靶区剂量分布没有统计学差异的情况下,IMAT技术能显著降低机器跳数,大大缩短治疗时间。Objective： To compare the dosimetric difference of intensity-modulated arc radiotherapy （ IMAT） with dynamic intensity-modulated radiation therapy （ dIMRT） in stage T2 nasopharyngeal carcinoma. Methods：Ten cases with stage T2 nasopharyngeal carcinoma were randomly selected from NPC patients. For these cases, the treatment plans were designed with dIMRT, and were replaned with IMAT. The isodose distribution, the dosimetric parameters of target volumes and organs at risk （ ORA） , monitor units （ MU） and treatment time were compared between the two techniques. Results：There was no significant difference between the IMAT and the dIMRT in dose received by 98%, 95% and 2% of planning target volumes （P〉0. 05）. Compared with dIMRT, IMAT reduced the dose of brainstem （Dmax and D1cc）, spinal cord （Dmax）, right parotid （Dmean）,right mandible joint（Dmax） and left cochlea（Dmean and Dmax）, and increased the dose of lens （ Dmax） , optic nerves（ Dmax） and chiasm （ Dmax） . In normal tissue, there were significant differences for V20 and V30 （P〈0. 05）. Mean monitor units were 1 582 and 839 for dIMRT and IMAT （reduced by 47. 0%）, mean treatment time was 14. 1 min and 7. 3 min for dIMRT and IMAT （reduced by 48. 2%）. Conclusion： For stage T2 naso-pharyngeal carcinoma, IMAT and dIMRT can achieve equal targets coverage. Compared with dIMRT, IMAT decreases not only the MUs and the treatment times, but also the dose for some organs at risk.

关 键 词：鼻咽癌 旋转调强 固定野动态调强 剂量 

分 类 号：R730.55[医药卫生—肿瘤] R739.63[医药卫生—临床医学]