直肠癌术前旋转调强与传统固定野动态调强放疗计划对比研究  

Comparison of intensity-modulated arc therapy with conventional intensity-modulated radiotherapy in treatment planning system for preoperative radiotherapy of rectal cancer

作　　者：熊英[1] 周伟[1] 毛凯[1] 戴甜甜[1] 韩媛媛[1] 

机构地区：[1]中日友好医院放射治疗科,北京100029

出　　处：《中日友好医院学报》2014年第2期92-94,98,共4页Journal of China-Japan Friendship Hospital

摘　　要：目的:探讨快速旋转调强(IMAT)技术在直肠癌术前放疗中的潜在优势。方法:选择22例直肠癌术前患者,计划靶区(PTV)剂量为50Gy,2Gy/次,5次/周。用治疗计划系统分别进行IMAT和固定野动态调强放疗(IMRT)计划设计,比较2组计划实施时的机器跳数、治疗时间、靶区适形度指数、均匀性指数、危及器官的受照剂量与体积。结果:IMAT计划与传统IMRT计划相比,其机器跳数及治疗时间显著缩短(P<0.05)。IMAT计划的适形指数及靶区的均匀性指数与IMRT相比无统计学差异(P>0.05)。在评价相关危及器官的关键参数如V20、V30、V40和V50中,IMAT计划中膀胱高剂量区受照射体积较IMRT显著减少(P<0.05)。结论:IMAT治疗计划中治疗时间和治疗跳数的显著减少大幅提高了其治疗效率,相应降低了放疗诱发第二肿瘤的风险。IMAT可以达到与IMRT同样的剂量分布,并且其对周围相邻膀胱组织的保护更好。Objective：To investigate the potential advantages of intensity-modulated arc therapy（IMAT）applied to the radiotherapy of the preoperative rectal cancer.Methods：Twenty two preoperative patients with rectal cancer were selected to be treated with a dose of 50Gy at planning target volume （PTV）,and divided into 25 fractions.Two techniques,intensity modulated radiation therapy（IMRT）and IMAT,were used respectively to com- pare treatment times,monitor units,target conformities,homogeneity index and dose-volume histogram data.Re- suits：In terms of delivery both the time and required monitor unit showed statistically significant difference（P〈 0.05）.There were no differences in the conformal index （CI）,homogeneity index （HI）（P〉0.05）.With respect to the key parameters of irradiated volume such as V20,V30,V40 and VS0 of risk organs,the exposure volume of bladder in high dose region by IMAT was lower than those by IMRT （P〈0.05）.Conclusion：Treatment effi- ciency is substantially improved with the reduction in treatment time by IMAT.The risk of radiation induced malignancy can be reduced due to less monitor unit per dose.Equivalent target coverage and dose conformity is observed with the double plans and indicates a good sparing of surrounding bladder in the IMAT plan.

关 键 词：快速旋转调强 固定射野动态调强 直肠癌 剂量学 

分 类 号：R735.37[医药卫生—肿瘤]