摘要
目的:探讨限量环个数对宫颈癌固定野调强放疗计划的影响,为限量环的个数设置提供参考。方法:选取于某院行宫颈癌根治术后调强放疗患者30例,基于CMS XiO 4.80计划系统分别对同一患者设计无限量环(Plan_0)、1个限量环(Plan_1)、2个限量环(Plan_2)、3个限量环(Plan_3)共4种放疗计划,所有计划除限量环外,均采用相同的目标函数和剂量限制条件,靶区处方剂量均为4 500 cGy/25 f。采用SPSS 18.0统计学软件比较分析4种计划的剂量学参数、二维剂量验证通过率、机器跳数、子野个数及治疗时间的差异。结果:4种计划均满足靶区剂量要求,所得靶区剂量学参数无统计学差异(P>0.05)。Plan_2与Plan_3中小肠、直肠和膀胱的V20(V20为2 000 cGy所包绕的体积,以此类推)、V30和V40,双侧股骨头V20,骨盆V10、V20、V30和V45及正常组织V15、V20和V25均比Plan_0与Plan_1低(P<0.05)。Plan_3较Plan_2而言,机器跳数增加约111 MU,子野数增加约12个,治疗时间增长约2.3 min(P<0.05)。结论:2个限量环的调强放疗计划在满足靶区剂量要求并对治疗效率影响较小的前提下,能较好地保护危及器官和正常组织,建议采用CMS XiO 4.80计划系统设计宫颈癌固定野调强放疗计划时设置2个限量环。
Objective To investigate the effect of the number of dose-limiting rings on fixed-fields IMRT plan for cervical cancer,and to provide reference for setting the number of limiting dose rings.Methods Thirty patients with radical surgery for cervical cancer receiving intensity modulated radiotherapy in some hospital were enrolled in the study.Non-limiting dose ring(Plan_0),1-limiting dose ring(Plan_1),2-limiting dose ring(Plan_2)and 3-limiting dose ring(Plan_3)plans were designed for the same patient based on CMS XiO 4.80.All the plans were designed with the same objective function and dose limiting condition.The prescription dose of target was 4 500 cGy/25 f.The difference of dosimetric parameters,two-dimensional dose passing rate,monitor units,NO.of segments and treatment time for all the plans were compared with SPSS 18.0 statistical software.Results All the plans satisfied target dose requirements,and the dosimetric parameters showed no significant difference(P>0.05).Compared with Plan_0 and Plan_1,Plan_2 and Plan_3 had the V20(V20 represented the volume involved in case of 2 000 cGy,and so on),V30 and V40 of small bowel,rectum and bladder,the V20 of bilateral femoral heads,the V10,V20,V30 and V45 of pelvic and the V15,V20 and V25 of normal tissue lower significantly(P<0.05).Compared with Plan_2,Plan_3 had the average monitor units increased by 111 MU,the average NO.of segments by 12 and the average treatment time by 2.3 min(P<0.05).Conclusion When the fixed-fields IMRT plan for cervical cancer is designed by CMS XiO 4.80,it’s suggested that two dose-limiting rings be applied in consideration of target dose requirements,fewer influences on treatment efficiency and better protection for organs at risk(OAR)and normal tissues.
作者
陈颖
钟志鹏
焦杨
刘茹佳
CHEN Ying;ZHONG Zhi-peng;JIAO Yang;LIU Ru-jia(Department of Radiation Oncology,Jingmen NO.2 People's Hospital,Jingmen 448000,Hubei Province,China)
出处
《医疗卫生装备》
CAS
2019年第11期33-37,共5页
Chinese Medical Equipment Journal
基金
荆门市引导性科研计划项目(2018YDKY039)
关键词
宫颈癌
限量环
固定野
调强放疗
剂量学
cervical cancer
dose-limiting ring
fixed-field
IMRT
dosimetry
