探讨CT引导下宫颈癌腔内后装治疗逆向和常规计划与HR-CTV体积关系  

Exploration of the relationship between the tumor size of the HR-CTV and the reverse or conventional plan in CT-based cervical brachytherapy

作　　者：鲁文力 李英[1] 崔海霞 姜庆丰[1] 黄维[1] Lu Wenli;Li Ying;Cui Haixia;Jiang Qingfeng;Huang Wei(Department of Oncology,The First Affiliated Hospital of Chongqing Medical University)

机构地区：[1]重庆医科大学附属第一医院肿瘤科,重庆400016

出　　处：《重庆医科大学学报》2019年第1期43-48,共6页Journal of Chongqing Medical University

摘　　要：目的:在宫颈癌腔内后装治疗中,探讨逆向计划和常规计划与高危临床靶区(the high-risk clinical target volume,HRCTV)的体积关系。方法:收集2015年4月至2016年8月于我院接受CT图像引导下的三维腔内后装治疗患者66例,按HRCTV体积大小分为6组[～30 cm3(n=9)、～45 cm3(n=10)、～60 cm3(n=17)、～75 cm3(n=11)、～90 cm3(n=8)、>90 cm3(n=11)]。每例患者同时制定逆向计划和常规计划。利用剂量体积直方图(dose volume histogram,DVH)比较2种计划方式在不同体积范围内的优劣,评估参数包括危及器官(膀胱、直肠和乙状结肠)的D1 cm3、D2 cm3、Dmean、6 Gy处方剂量覆盖体积、不均匀指数(heterogeneity index,HI)和适形指数(conformal index,CI)。结果:(1)～75 cm3组2种计划在危及器官保护、6 Gy靶区覆盖、HI和CI值中均无差异;(2)HR-CTV体积<60 cm3时,选择逆向计划更能保护危及器官;(3)HR-CTV体积>75 cm3,常规计划更能保护危及器官但是靶区覆盖欠佳,逆向计划反之。结论:对于<60 cm3靶区,逆向计划更能保护危及器官;而>75 cm3靶区,2种计划对于保护危及器官和靶区覆盖均无明显优势,建议应用插植或者插植与腔内后装相结合的技术。Objective:To explore the relationship between the tumor size of the high-risk clinical target volume(HR-CTV) and the reverse or conventional plan in CT-based cervical brachytherapy. Methods:Sixty-six patients treated by the CT-based intracavitary brachytherapy for cervical cancer in our hospital from April 2015 to August 2016 were enrolled and divided into 6 groups according to the tumor size[-30 cm^3 group(n=9),-45 cm^3 group(n=10),-60 cm^3 group(n=17),-75 cm^3 group(n=11),-90 cm^3 group(n=8),and >90 cm^3 group(n=11)]. Each patient underwent both the reverse plan and the general plan,the superiority of which was acquired by dose volume histogram(DVH),with D1 cm^3,D2 cm^3,and Dmean of bladder,rectum and sigmoid colon,6 Gy prescription dose coverage volume,heterogeneity index(HI) and conformal index(CI) as evaluation parameters. Results:①All evaluation parameters in -75 cm^3 group showed no significant difference between the two plan. ②In the groups with tumor size <60 cm^3,the reverse plan was superior to the general plan for protecting organs at risks. ③In the groups with tumor size >75 cm^3,the general plan was superior to the reverse plan for protecting organs at risks,but inferior for target coverage volume. Conclusion:The research suggests that if the tumor size is smaller than 60 cm^3,the reverse plan is superior to the general plan for protecting organs at risks. However,if the tumor size is bigger than 75 cm^3,both plans have no significant superiority for protecting organs at risks or target coverage,which suggests that the treat-ment should rely on the implant technique or a combination of the intracavitary brachytherapy and implant technique.

关 键 词：宫颈癌 三维后装治疗 逆向计划 常规计划 危及器官 最优体积 

分 类 号：R737.33[医药卫生—肿瘤]