CyberKnife等中心及非等中心立体定向治疗计划质量及效率评价  

Evaluation on Quality and Efficiency of Isocentric and Non-isocentric Stereotactic Treatment Plans From Cyber Knife

作　　者：朴俊杰[1,2] 徐寿平[1] 王金媛[1] 曲宝林[1] 段学章[2] 巩汉顺[1] 徐慧军[2] 

机构地区：[1]解放军总医院,100853 [2]解放军第302医院,100039

出　　处：《实用癌症杂志》2016年第5期747-751,共5页The Practical Journal of Cancer

基　　金：国家自然科学基金(编号:61171005)

摘　　要：目的探讨并评价Cyber Knife(CK)系统利用等中心和非等中心两种计划模式立体定向治疗计划(SRT)的剂量学特性及差异。方法将18例肿瘤患者分为A、B两组:A为小体积组即肿瘤大小在3 cm以下;B为大体积组即肿瘤大小在3 cm以上。每组9例患者计划分别给予同一处方剂量条件40 Gy/5F。在相同的条件下,分别以等中心和非等中心两种布野方式立体定向治疗技术设计相应的计划,通过其靶区适形指数(CI)、非均匀指数(HI)、梯度指数(GI)和危及器官等剂量学参数,分析评估SRT计划优化质量及实施效率,从而实现评价两种治疗模式的剂量学差异。结果等中心组计划执行的平均治疗时间(P=0.002)及机器MUs(P<0.001)明显优于非等中心组;CI均值(A:P=0.027;B:P=0.007)和GI均值(A:P<0.001;B:P<0.001)分别小于非等中心组;HI均值则略高于非等中心组(A:P=0.029;B:P<0.001);A组平均剂量归一值(P=0.011)等中心组优于非等中心组,而B组(P=0.012)等中心组低于非等中心组。结论等中心治疗模式在治疗时间、MU数及GI上均优于非等中心,在CI和HI上略低于非等中心模式。小体积肿瘤可考虑等中心治疗模式,而大体积肿瘤则宜用非等中心治疗模式;但仍需更多的临床病例给予研究。Objective To study the dosimetric charateristics and differences of Isocentric and non-isocentric stereotactic radiotherapy plans are used in Cyber Knife system. Methods 18 patients were divided into group A and group B. The size of tumors in group A was smaller than 3 cm,and the size of tumors in group B was more than 3 cm. Each group included 9 patients,and both groups were prescribed dose of 40 Gy /5F. The isocentric and non-isocentric techniques were independently used for designing the corresponding treatment plans. The dosimetric parameters,such as conformation index（ CI）,heterogeneity index（ HI）,gradient index（ GI） and organs at risks（ OARs）,were used to evaluate the quality of optimization and efficiency of implementation of stereotactic radiotherapy plans for 2 techniques. Results The average treatment time（ A： P = 0. 002; B： P = 0. 002） and MUs of the machine（ A： P〈0. 001; B： P〈0. 001） in the isocentric plans were obviously superior to the non-isocentric plans. The mean values of CI（ A： P = 0. 027,B： P = 0. 007） and GI（ A： P〈0. 001; B： P〈0. 001） for the isocentric group were slightly smaller than those of the non-isocentric group. And the mean values of HI（ A： P = 0. 029,B： P〈0. 001） in the isocentric plans was larger than that in the non-isocentric plans. In group A,the normalized average dose（ P = 0. 011） of the isocentric plans was superior to that of the non-isocentric plans. But in group B,the normalized average dose（ P = 0. 012） of the isocentric plans was inferior to that of the non-isocentric plans. Conclusion The isocentric plans are better than the non-isocentric plans in the treatment time,MUs and GIs. And it is inferior in CIs and HIs. The isocentric plans may be used for designing in small tumors and the non-isocentric plans may be better for large tumors. Of course,more clinical cases should be done for further research.

关 键 词：CYBER KNIFE 等中心 非等中心 计划质量 剂量学 

分 类 号：R730.5[医药卫生—肿瘤]