子野权重优化对CMS XiO宫颈癌调强计划的影响  

A Study of Segment Weight Optimization With the CMS XiO Step-and-shoot IMRT Technique for Cervical Cancer

作　　者：查元梓[1] 张松方[1] 屠永清[1] 王为[1] 蒋马伟[1] 

机构地区：[1]上海交通大学医学院附属新华医院肿瘤科,上海200092

出　　处：《中国医学物理学杂志》2013年第1期3866-3869,共4页Chinese Journal of Medical Physics

摘　　要：目的：本文分析了CMS治疗计划系统XiO在制定调强放射治疗（IMRT）计划时，子野权重优化对治疗计划结果的影响。方法：本文选取10例宫颈癌全程放射治疗病例，制定影像引导下（IGRT）的调强放射治疗计划，首先直接用静态调强（Step＆Shoot）方式进行优化一步生成调强放射治疗计划（S-IMRT），之后继续进行子野权重优化（Segmentweightop—timization，SWO）并生成新的治疗计划（SWO—IMRT），比较子野权重优化前后总子野数、总跳数，同时分析比较正常组织受照剂量的变化。结果：结果显示，经过子野权重优化后，总的子野数显著减少，减少约26％～31％（p〈0．0001）；总的机器跳数有所降低，减少约5．1％～9．7％（p〈0．0001），同时，直肠、膀胱和小肠的剂量也有所降低。结论：在使用CMS治疗计划系统XiO进行宫颈癌全程调强放射治疗计划设计过程中，充分利用子野权重优化方式，可以减少总的机器跳数，降低正常组织剂量，缩短治疗时间，这既降低正常组织的毒性反应，也为肿瘤剂量的提高提供了可能。在其他病种的调强放射治疗计划设计中．子野权重优化也可以发挥重要的作用。Objective： The aim of this study is to compare the result of IMRT optimization in the CMS XiO radiotherapy treat- merit planning system, with and without segment weight optimization. Methods：Ten cervical cancer patients were selected for this study. All patients were initially planned with step-and-shoot IMRT （S-IMRT）. A new plan was then created for each pa- tient by applying the segment weight optimization tool （SWO-IMRT）. Analysis was performed on the （SWO-IMRT） and （S-IM- RT） plans by comparing the total number of segments, monitor units, rectal, bladder and small intestine dose. Results： The study showed a significant reduction in the total number of segments about26%-31% （p〈0.0001） with SWO-IMRT as compared to S-IMRT. Similarly, a reduction of 5.1%-9.7% （p〈0.0001） in the total MU was observed with SWO-IMRT. The method also reduced the dose of rectal, bladder and small intestine. Conclusions： This study shows that for IMRT plan of the cervical can- cer, XiO＇ s segment weight optimization method can reduce the total number of monitor units, segments and the normal tissue＇ s dose. SWO-IMRT also accelerates treatment delivery. This can reduce normal tissue＇ s toxicity and provide an opportunity for dose escalation of GTV. For other kinds of IMRT cases, SWO-IMRT can also play important roles.

关 键 词：调强放射治疗 XiO2 子野权重优化 宫颈癌 

分 类 号：R730.55[医药卫生—肿瘤] R737.33[医药卫生—临床医学]