鼻咽癌螺旋断层放疗与调强放疗的剂量学比较

The Comparation of Dosimetry Difference between the Tomotherapy and Intensity Radiation Therapy for Nasopharyngeal Carcinoma

目的：比较螺旋断层放疗（Tomotherapy）和调强放疗（Intensity radiation therapy,IMRT）在鼻咽癌应用中的剂量学差异。方法：选择7例已经在本院完成IMRT治疗的T3期鼻咽癌患者,将其CT图像和靶区传输至螺旋断层放疗系统重新设计治疗计划,评估靶区以及危及器官（OA R）的剂量分布、剂量学参数。使用SPSS19.0统计学软件对两组数据进行配对t检验。结果：Tomotherapy计划组靶区剂量分布更加均匀,剂量梯度更加陡直,所有靶区的均匀性指数均优于IMRT组。腮腺的平均剂量和30Gy所占的体积均明显优于IMRT。Body的V20~V50剂量跌落快。结论：两组计划的剂量分布存在一定差异但均能满足临床要求,Tomotherapy系统在鼻咽癌放疗中具有明显的剂量学分布优势,尤其是腮腺的受量。

Objective： To compare the dosimetry difference between the Tomotherapy and intensity radiation therapy （IMRT） for nasopharyngeal carcinoma. Methods： Seven patients with nasopharyngeal carcinoma（T3）who accepted IM- RT were included in this study. The treatment planning were re-designed by transmitting CT imaging and target area to the Tomotherapy system. The dose distribution, dosimetry parameter and organs at risk（OAR）were evaluated. The SPSS19.0 was used to perform the pared-t test for the data of two groups. Results.. The targets dose distribution and dose gradient of Tomotherapy group were better than those of IMRT. In addition, the homogeneity indices of all targets in Tomotherapy group were superior to those of IMRT. The Dmean and V30 of parotids were significantly better than those of IMRT. The V20 -V50 of Body falls faster. Conclusion： There is a slight difference in dose distribution between Tomotherapy and IMRT,but they both meet the clinical needs, while Tomotherapy is supprior to IMRT in optimizing dose distribution,especially the exposure of parotids.