利用MVCT图像引导技术分析肝脏恶性肿瘤放疗不同体位固定方式的摆位误差  

Analysis of positioning deviation of different body position fixing methods for hepatic carcinoma patients with radiotherapy by MVCT

作　　者：丁伟杰[1] 曾昭冲[1] 孙菁[1] 陈一兴[1] 

机构地区：[1]复旦大学附属中山医院放疗科,上海200032

出　　处：《中国临床医学》2016年第3期341-343,共3页Chinese Journal of Clinical Medicine

摘　　要：目的:在螺旋断层放疗中,应用兆伏级高能X线计算机体层摄影(MVCT)图像引导技术,分析肝脏恶性肿瘤放疗中患者两种不同体位固定方式的摆位误差。方法:收集2015年3月至10月进行螺旋断层放射治疗的40例肝脏恶性肿瘤患者的摆位数据,将其分为体模组和体架组。每次治疗前进行MVCT扫描,获得相应的线性摆位误差和旋转摆位误差。对两组摆位数据进行均值方程t检验。根据外扩公式M=2.5Σ+0.7δ,计算PTV外扩边界值。结果:两组X轴、Z轴上的的摆位差异有统计学意义(t=22.02、2.56,P=0.04、0.01),Pitch、Yaw上的摆位差异亦有统计学意义(t=22.16、2.26,P=0.03、0.02)。体模组PTV外扩边界值为8.29、9.87、7.72 mm;体架组PTV外扩边界值为4.81、5.27、4.57 mm。结论:螺旋断层放疗中,MVCT图像引导技术可以很好地提高肝脏恶性肿瘤患者的放疗精度;体架固定能够更好地固定肝脏恶性肿瘤患者,在治疗时,其产生的摆位误差明显小于体模固定,且能缩小PTV边界。Objective：To analyze the positioning deviation of two different body position fixing methods for hepatic carcinoma patients by meta-voltage computed tomography（MVCT）.Methods：The positioning data of 40 hepatic carcinoma patients treated by helical tomotherapy during March to October,2015 in our Department of Radiotherapy were collected and divided into two groups：users of carbon fiber fixator with vacuum pad（Group C）and users of the vacuum bag（Group V）.MVCT scan was performed before each treatment,and the amount of both linear and rotary positioning deviation was obtained.The two sets of data were compared through mean functional t-test.Finally,PTV extended boundary was calculated according to the extension formula M=2.5Σ＋0.7δ.Results：From deviation direction of linear positioning,the differences of X-axis and Z-axis on two sets of data had statistical significance（t=22.02,2.56;P=0.04,0.01;P〈0.05）.From deviation direction of rotary positioning,the differences of Pitch and Yaw on two sets of data also had statistical significance（t=22.16,2.26;P=0.03,0.02;P〈0.05）.PTV extended boundary of Group V were 8.29 mm,9.87 mm and 7.72 mm.PTV extended boundary of Group C were 4.81 mm,5.27 mm and 4.57 mm.Conclusions：In helical tomotherapy,MVCT image guidance technology could enhance the accuracy of radiotherapy for hepatic carcinoma patients.Compared with vacuum bag,carbon fiber fixator could fix the patients better,which could reduce positioning deviation and PTV boundary.

关 键 词：肝脏恶性肿瘤 兆伏级高能X线计算机体层摄影 摆位误差 外放边界 

分 类 号：R815.2[医药卫生—放射医学]