锥形束CT图像引导对肺癌放疗摆位误差分析及CTV-PTV外放边界的研究  

The effect of setup error and expanding margins of CTV-PTV in lung cancer radiotherapy with cone-beam CT image guide

作　　者：李怀永[1] 马常英[1] 强俊豪 鲁亚晶[1] Li Huaiyong;Ma Changying;Qiang Junhao;Lu Yajing(Department of Radiotherapy,First Hospital of Qiqihar City,Qiqihar,Heilongjiang 161000,China)

机构地区：[1]齐齐哈尔市第一医院放疗科,黑龙江齐齐哈尔161000

出　　处：《影像研究与医学应用》2021年第6期17-18,23,共3页Journal of Imaging Research and Medical Applications

基　　金：齐齐哈尔市科技计划创新激励项目(CSFGG-2020049)。

摘　　要：目的:该研究旨在通过千伏锥形束CT(cone-beam CT,CBCT)对肺癌调强放疗摆位误差分析,确定临床靶区(clinical target volume,CTV)外扩至计划靶区(planning target volume,PTV)边界的大小。方法:2019年1—12月在我院全程进行图像引导放射治疗的63例肺癌患者,将首次及之后每周放疗前CBCT扫描得到的CBCT图像与定位C T图像匹配,获得左右,头脚和背腹方向的摆位误差值,并计算CTV外扩至PTV的边界MPTV。结果:63例患者共获得474幅CBCT图像。分析得到X左右方向的误差为(2.0570±1.5562)mm,Y头脚方向误差为(2.1709±1.6432)mm,Z背腹方向误差为(1.8291±1.3726)mm。根据摆位误差得到MPTV在X左右、Y头脚、Z背腹方向分别为2.8612 mm,3.2930 mm,2.9881 mm。结论:应用CBCT测量和分析肺癌治疗前的摆位误差规律,并计算CTV外扩边界的大小,可以为本科外扩CTV边界提供理论依据,具有临床意义。Objective The purpose of this study was to determine the expanding margins of CTV-PTV through measure and analyze the setup errors of intensity modulated radiotherapy for lung cancer with Kilovolt cone-beam computed tomography(CBCT).Methods The set-up errors of 63 patients undergoing image guided radiotherapy in our hospital from January to December in 2019 were enrolled in the study.Each patients underwent radiotherapy with CBCT before the first and latter per week treatment.Setup errors in CBCT were obtained according to the matched and planned CT images in laternal(LAT),longitudinal(LNG)and Vertical(VRT)directions.The expanding margins of clinical target volume(CTV)to planning target volume(PTV)according to the analyzed setup errors were then calculated.Results A total of 474 CBCT images from 63 patients were obtained during the treatment.The setup errors were(2.0570±1.5562)mm,(2.1709±1.6432)mm and(1.8291±1.3726)mm in the LAT,LNG and VRT directions,respectively.The suggested margins of CTV to PTV were 2.8612mm,3.2930mm,2.9881mm in the LAT,LNG and VRT directions according to setup errors.Conclusion It laid a practical clinical significance foundation for calculating our CTV margins by measuring and analyzing the setup errors with using CBCT.

关 键 词：锥形束CT 肺癌 摆位误差 M_(PTV) 

分 类 号：R734.2[医药卫生—肿瘤]