基于Flatten-Filter Free模式治疗原发性肝癌的剂量学研究  

Dosimetric study on Flatten-Filter Free for primary liver cancer

作　　者：侯勇[1] 黄瑞彬[2] 范医鲁[1] 

机构地区：[1]山东省千佛山医院肿瘤放疗科,山东济南250012 [2]济南市第四人民医院CT室,山东济南250011

出　　处：《中国医学物理学杂志》2015年第4期590-594,598,共6页Chinese Journal of Medical Physics

摘　　要：目的:比较原发性肝癌的Flatten-Filter Free(FFF)模式和Flatten Filter(FF)模式的单弧、双弧以及七野固定野治疗的剂量学差异。方法:选取13例原发性肝癌患者,在增强CT图像上勾画靶区及危及器官和正常组织,并在同一套CT图片上设计单个全弧、双全弧和七野固定野的FFF模式和FF模式的调强计划,病人总的治疗剂量200 c Gy×30次。通过剂量体积直方图统计PTV相关的剂量学参数、适形度指数(CI)、均匀性指数(HI),肝脏的剂量体积学参数、机器跳数、治疗时间和计划时间等利用SPSS20.0进行配对非参数Wilcoxson符号秩检验的统计学处理。结果:3种放疗计划FF和FFF模式靶区的HI和CI均没有统计学差异(P>0.05),靶区的V95%、最大剂量、最小剂量和平均剂量有统计学差异(P<0.05),在单弧、双弧和七野固定野调强计划的FF和FFF模式中,靶区的V95%FFF比FF分别低34.3%、13%、1.2%,靶区最大剂量FFF模式比FF分别低1.54%、1.39%、2.2%,靶区的最小剂量分别降低17.9%、6.6%、9.23%,平均剂量分别降低9.23%、2.0%、2.3%。结论:FFF模式可以有效降低正常肝脏组织受量,减少病人治疗时间,可以在图像引导基础上进一步提高放疗的安全性。Objective To compare the dosimetric characteristics of one-arc, double-arc and fixed seven-beam intensity modul- ated radiotherapy （IMRT） based on Flatten-Filter Free （FFF） model and Flatten Filter （FF） model for primary liver cancer. Methods Thirteen patients with primary liver cancer were selected. The planning target volume （PTV）, organs at risk （OARs） and normal tissues were delineated on enhanced CT image. The one-arc, double-arc, and fixed seven-beam IMRT plans based on FFF model and FF model were designed on the same set of CT image. The total therapeutic dose was 200 cGy × 30 times. The dosimetric parameters related to statistical PTV on dose volume histogram （DVH）, conformity index （CI）, homogeneity index （HI）, dose volume parameters of livers, monitor units, therapy time and plan time underwent Non-parametric Wilcoxon Matched-Pairs Signed-Ranks Test by SPSS20.0. Results There were no significant differences between these plans based on FFF model and FF model in HI, CI （P〉0.05）. However, there were significant statistical differences in the V95%, maximum dose, minimum dose and mean dose of PTV （P〈0.05）. The V95%. of PTV in one-arc, double-arc and fixed seven-beam IMRT plans based on FFF model was separately 34.3%, 13%, 1.2% lower than that in those plans based on FF model, and the maximum dose of PTV in these plans based on FFF model was separately 1.54%, 1.39%, 2.2% lower, and the minimum dose of PTV of these plans based on FFF model was separately 17.9%, 6.6%, 9.23% lower, and the mean dose of these plans base on FFF model was separately 9.23%, 2.0%, 2.3% lower. Conclusion FFF can effectively reduce the normal liver tissue dose, reduce the duration of treatment and further improve the safety of radiotherapy.

关 键 词：原发性肝癌 旋转调强放疗 无均整滤线器 剂量 

分 类 号：R815.2[医药卫生—放射医学] R735.7[医药卫生—临床医学]