应用锥形束CT分析宫颈癌放射治疗中的摆位误差  

ANALYSIS OF POSITIONING ERRROS WITH CONE BEAM CT IN RADIOTHERAPY OF CERVICAL CANCER

作　　者：乌晓礼[1] 王利华[1] 索志敏[1] 郁志龙[1] 

机构地区：[1]内蒙古医科大学附属医院放疗科,内蒙古呼和浩特010050

出　　处：《内蒙古医科大学学报》2013年第6期438-441,共4页Journal of Inner Mongolia Medical University

基　　金：内蒙古自然科学基金(2010MS1145)

摘　　要：目的:通过由图像引导的加速器配备的锥形束CT(Cone beam CT,CBCT)了解本中心现有的定位方式引起的临床上的摆位误差,指导制定放射治疗计划过程中的PTV(planning target volume)外放范围。方法:在放射治疗过程中,完成病人摆位后拍摄病人的锥形束CT图像与治疗计划设计时的CT图像的匹配,获得病人的摆位误差,把其平均值和标准差分别做为系统误差和随机误差,通过公式M PTV(外放)=2.5Σ+0.7σ获得三维方向上的肿瘤靶区外放边界。结果:得到校位前病人三个方向的外放数据如下X=5.80mm,Y=6.22mm,Z=5.06mm。校位后病人三个方向上的外放数据如下:X=2.55mm,Y=2.79mm,Z=1.93mm。结论:图像引导放射治疗方式可有效减小肿瘤靶区的外放边界,两种治疗方式应选择不同的外放边界。Objective:To study the positioning errros data caused by positioning method,the data were obtained from CBCT images and were used to guide the PTV margin clinically. Methods:CBCT images during the course of radiotherapy after completion of patient positioning were matched with CT images of the treatment planning,then the mean value and standard deviation of the positioning errros data were obtained,the external tumor target boundaries In three dimensions direction were obtained by the formula of MPTV(free)=2. 5Σ +0. 7σ and systematic errors and random errors as the mean value and standard deviation of the positioning errros data. Results:The external data in three directions pre-correction as follows:X=5. 80mm,Y=6. 22mm,Z=5. 06mm,the external data in three directions post-correction as follows:X = 2. 55 mm, Y = 2. 79 mm, Z = 1. 93 mm. Conclusion:Image-guided radiotherapy methods can effectively reduce the external tumor target boundaries, both treatment methods should choose a different external boundaries.

关 键 词：宫颈癌 锥形束CT 图像引导 摆位误差 

分 类 号：R815[医药卫生—放射医学]