CT-MRI图像融合对前列腺癌调强放疗靶区及正常组织剂量影响  

Influence of CT/MRI image fusing technique on target volume and dosimetrics of normal tissues in intensity modulated radiotherapy for prostate carcinoma

作　　者：王朝阳[3] 王维虎[1] 李晔雄[1] 田源[1] 胡志辉[1] 房辉[1] 刘莉[2] 金晶[1] 刘跃平[1] 王淑莲[1] 宋永文[1] 刘新帆[1] 余子豪[1] 汪华[1] 刘清峰[1] 亓妹楠[1] 

机构地区：[1]中国医学科学院北京协和医学院肿瘤医院肿瘤研究所放疗科,北京100021 [2]中国医学科学院北京协和医学院肿瘤医院肿瘤研究所影像诊断科,北京100021 [3]广西医科大学第四附属医院肿瘤科,柳州545005

出　　处：《中华放射肿瘤学杂志》2010年第5期452-455,共4页Chinese Journal of Radiation Oncology

基　　金：卫生部临床学科重点项目（07090010）

摘　　要：目的 探讨CT-MRI图像融合对前列腺癌调强放疗靶区及正常组织剂量影响.方法 对10例经病理证实的中高危局限期前列腺癌患者行CT模拟定位和MRI图像采集.用CT-MRI图像融合软件确定同层面CT和MRI图像,分别在其上勾画前列腺和精囊腺靶区、直肠、膀胱等并对靶区进行调强放疗计划设计,比较它们在直肠和膀胱的剂量体积直方图参数间差异.结果 CT、MRI图像上勾画的前列腺＋精囊腺平均体积分别为84.03、53.53 cm3（t=2.47,P=0.024）,基于CT和MRI图像进行调强放疗计划设计后直肠V50、V60、V70分别为37.03%和30.28%（t=2.71,P=0.014）、24.99%和19.13%（t=2.83,P=0.011）、14.55%和9.53%（t=3.19,P=0.005）;膀胱最大剂量分别为82.45 Gy和81.10 Gy（t=2.41,P=0.027）.结论 MRI图像上勾画的前列腺＋精囊腺体积比CT图像上勾画的小,基于MRI图像勾画靶区制定调强放疗计划比基于CT图像的可明显减少受较高剂量照射的直肠体积.Objective To explore the influence of computed tomography （CT） and magnetic resonance imaging （MRI） fusing technique on target volume and dosimetrics of normal tissues in intensity modulated radiotherapy （IMRT） for prostate carcinoma.Methods Ten patients with pathologically diagnosed moderate-high risk localized prostate carcinoma were enrolled in this study.CT and MRI images were collected.Same image slices of the prostate, seminal vesicles, rectum and bladder were anatomically delineated using image fusing software.Clinical target volume （CTV） was defined as the prostate plus seminal vesicles.IMRT treatment planning was designed basing on CT and MRI images, respectively.Differences of CTV volume and dose volume histogram of rectum and bladder between the two image groups were analyzed.Results The mean volume of CTV on CT and MRI images was 84.03 cm3 and 53.53 cm3,respectively （t =2.47,P=0.024）.The V50, V60 and V70 of rectum were 30.28%, 19.13%, 9.53% on MRI and 37.03%, 24.99% and 14.55% on CT images, respectively, with significent difference （t =2.71,P=0.014 for V50; t =2.83,P=0.011 for V60; t=3.19,P=0.005 for V70）.The maximal dose of bladder was 81.10 Gy on MRI and 82.45 Gy on CT, respectively（t=2.41,P=0.027）.Conclusions By using image fusing technique, the mean volume of the prostate plus seminal vesicles delineated on MRI image is smaller as compared to CT image.The volume of the rectum receiving high irradiation dose can be reduced when MRI was used to delineate CTV compared to CT image.

关 键 词：图像融合 体层摄影术 X线计算机 磁共振成像 前列腺肿瘤/调强放射疗 

分 类 号：R686[医药卫生—骨科学]