中国全科医学2016，Vol.19Issue(21)：2591-2595,5.DOI:10.3969/j.issn.1007-9572.2016.21.020
锥形束 CT 评价前列腺癌容积调强弧形放射治疗分次间摆位误差及外放边界研究
Evaluation of Intrafraction Setup Error and Margin in VMAT for Prostate Cancer by Cone Beam CT
摘要
Abstract
Objective To investigate the intrafraction setup error in volumetric intensity modulated arc therapy (VMAT)for prostate cancer patients using cone beam CT( CBCT),and to study the proper margin required to expand the clinical target volume(CTV)to create a planning target volume( PTV). Methods From January to October in 2014,we enrolled 40 patients with prostatic cancer who received radical radiotherapy in the Department of Radiotherapy and Chemotherapy in the First Affiliated Hospital of Wenzhou Medical University. All the patients underwent VWAT. One hour before treatment,the patients were asked to drink 500 ml water to fill the bladder and rectum to the degree as they did during CT positioning. All the patients received CBCT scanning after the first intrafraction setup to get setup errors before adjustment,and underwent VMAT after online adjustment. The whole process was conducted for all together 39 times,with 2 Gy per time and 5 times per week. The total dose of irradiation was 78 Gy. Results There were 640 sets of error data with 16 sets from each patient got by CBCT scanning. Statistic analysis showed that the intrafraction setup errors of left - right,head - toe and belly - back were(0. 14 ± 0. 10)cm, (0. 28 ± 0. 13) cm,and(0. 18 ± 0. 12) cm respectively. Margins calculated based on the equation MPTV= 2. 5Σ + 0. 7δ in the directions of left - right, head - toe and belly - back were 0. 41, 0. 80, and 0. 54 cm respectively. Conclusion CBCT can be used to verify the setup errors in VMAT for prostate cancer patients,and help adjust the errors to improve the accuracy of radiotherapy.关键词
前列腺肿瘤/容积调强弧形放射治疗/锥束计算机体层摄影术Key words
Prostatic neoplasms/Volumetric intensity modulated arc therapy/Cone - beam computed tomography分类
医药卫生引用本文复制引用
阎华伟,谢聪颖,金献测,杨桂强,张力,吴志勤,余建义,潘涵慧,林立,黄包记..锥形束 CT 评价前列腺癌容积调强弧形放射治疗分次间摆位误差及外放边界研究[J].中国全科医学,2016,19(21):2591-2595,5.基金项目
浙江省自然科学基金资助项目 （）
