杭霞瑜 1刘海 1李益坤 1王晓萍 1丁魏 1张新良1
作者信息
- 1. 中国人民解放军第八一医院全军肿瘤中心放疗科，江苏南京210002
- 折叠
摘要
Abstract
Objective To compare the treatment planning in Helical Tomotherapy (HT) and conventional intensity modulated radiation treatment(IMRT) system in 2 different dosimetry distribution of nasopharyngeal carcinoma (NPC), and analyze the target area and the dose to organ at risk. Materials and Methods Chose 18 cases of NPC and transfer their positioning data information and the outline of target organs to Tomotherapy workstation and TPS Varian Eclipse TPS workstation for the design of IMRT, and the prescription dose which used on these 18 patients are the same, with 73.92Gy/33 for the gross tumor volume(GTVnx);69.96 Gy/33F for the positive lymph nodes(GTVnd);60.06Gy/33F for the high risk clinical target volume (CTV1 );50.96Gy/28F for the lower risk clinical target volume (CTV2 ). Compared the treatment planning of the 2 groups through conformation number (CN), homogeneity index (HI) of the target area, and maximum and average dose of the organs at risk (OARs) , and performed a paired t test on the datas of the two groups. Results The CN of PGTVnx, PTV1, PTV2 in HT groups were 0.910 ± 0.010, 0.855± 0.020, 0.871±0.021, and in conventional IMRTgroups were 0.867±0.025, 0.822±0.020, 0.811±0.012. The HI of PGTVnx, PTV1, PTV2 in HT groups were 1.049±0.009, 1.135±0.030, 1.034±0.011, and in conventional IMRT groups were 1.060±0.011, 1.222±0.023, 1.094±0.015. P<0.005. Compared with the conventional intensity-modulated groups, in HT groups the CN and HI of target areas had improved with different degrees, the maximum and average dose to organs at risk were also decreased, average dose in parotid glands is about 4 Gy lower, V30, V35 were signiifcantly lower than that in conventional IMRT, P<0.005. Conclusion For NPC, compared with conventional IMRT technology, HT technique improves the dosimetry distribution, and helps target area to get better dose distribution and reduces the exposure dose to normal tissues at the same time.关键词
鼻咽癌/螺旋断层放疗/调强放疗/剂量学分析Key words
nasopharyngeal carcinoma/helical tomotherapy/intensity modulated radiation therapy/dosimetric analysis分类
能源科技
