膀胱和直肠体积变化对前列腺癌调强放疗靶区剂量的影响  

Effect of bladder and rectum volume changes on target dose distribution for image guided prostate cancer radiotherapy

作　　者：李明[1] 王婵[1] 李高峰[1] 张绍刚[1] 

机构地区：[1]北京医院放疗科,北京100730

出　　处：《医疗装备》2015年第6期5-9,共5页Medical Equipment

摘　　要：目的:应用图像引导放射治疗(Image—guided radiotherapy,IGRT)技术,观察膀胱、直肠在治疗中的变化,分析其对治疗的影响。方法:入选16例接受根治性调强放疗的前列腺癌患者,共行KVCBCT在线校正治疗体位214次。在模拟CT和锥形束CT(cone beam CT,CBCT)图像上勾画CTV、膀胱及直肠,观察膀胱、直肠体积和位置变化,分析其对治疗的影响。结果:治疗过程中膀胱和直肠的充盈度有较大变化。PTV95与膀胱、直肠的移动具有相关性,相关系数分别为0.293、0.171。直肠体积与PTV95的相关系数为0.112,说明两者存在一定相关性。对于PTVmin而言,除上述各指标之外,与膀胱体积有一定相关性,相关系数为-0.126。结论:在前列腺癌的调强治疗中,使膀胱、直肠尤其是后者尽量复原定位时状态,对保证靶区受量及减少直肠受照有明显意义。Objective： To observe the motions of normal tissues and organs, and analyze their impact on treatment by using image -guided radiotherapy （IGRT） . netheds： 16 patients with prostate cancer undergoing IMRT were enrolled onto the study and 214 CBCT imagings were obtained from this study. The CTV, bladder and rectum were contoured on all CT scans to examine their volume and position changes, and to evaluate their impact on the treatment. Results： Volumes of the bladder and rectum were observed to have a relatively significant variation during the treatment. There are correlations between PTV95 and the motions of bladder and rec- tum, correlation coefficients were O. 293 and 0. 171. The correlation coefficient of rectal volume and PTV95 was 0. 112, that there is a certain correlation. For PTVmin, in addition to the above indexes, and there is a certain correlation between bladder volume, the corre- lation coefficient is -0. 126. Conclusions： The state recovery when positioning of bladder and rectum especially the latter has obvious significance to ensure the target dose and reduce exposure of rectum for image guided prostate radiotherapy.

关 键 词：前列腺肿瘤/调强放射疗法 图像引导放射治疗 图像配准 剂量学 

分 类 号：TH774[机械工程—仪器科学与技术]