摘要
目的:探讨图像引导放疗技术(IGRT)在直肠癌患者术前新辅助调强放疗(IMRT)中的应用,分析其对靶区勾画的指导意义。方法:67例临床分期为Ⅱ~Ⅲ期(T3-4N0M0或T1-4N1-2M0)的直肠癌患者行术前IMRT,放疗期间每周行1次IGRT,获得术前和术后的2组影像在三维空间的对比位置误差,计算系统误差(Σ)和随机误差(σ),按照Van Herk公式计算计划靶区扩边值(MPTV)。结果:389个CBCT扫描图像在x、y、z 3个轴位方向上的误差范围分别为(0.86^-1.13)、(1.94^-2.11)及(1.87^-1.81)cm。校正后y轴和z轴上的平移误差小于校正前(t=3.541,P=0.001;t=3.275,P=0.000);校正后x轴和y轴上的旋转误差小于校正前(t=1.260,P=0.000;t=2.797,P=0.000。校正前,x、y、z 3个轴位方向上的MPTV分别为2.00、3.25和2.88cm,校正后为0.73、1.74和1.50cm,分别减少了1.27、1.51及1.38cm。结论:IGRT可减少直肠癌患者术前IMRT的系统误差和摆位误差,是精确放疗的有效质量保证。
Objective:To explore the application of image-guided radiotherapy technology(IGRT)in intensity modulated radiation therapy(IMRT)in the patients with rectal cancer before operation,and to analyze its guiding significance for target region.Methods:A total of 67 patients with rectal cancer(Ⅱ-Ⅲ stages,CT3-4N0M0 or CT1-4N1-2M0)were treated with IMRT before operation.IGRT was used for once a week during the radiotherapy and two sets of image contrast errors in the three-dimensional space were obtained.The systematic(Σ)and random(σ)setup errors were calculated.The MPTV was calculated according to the van Herk formula.Results:A total of389 CBCT scans were analyzed.The error range in the directions of e x,y,z axis were(0.86--1.13),(1.94--2.11),and(1.87--1.81)cm,respectively.The translation errors of the corrected y axis and z axis were less than those before correction(t=3.541,P=0.001;t=3.275,P=0.000);the rotation errors of the corrected x axis and y axis were less than those before correction(t=1.260,P=0.000;t=2.797,P=0.000).Before correction,the MPTV in the directions of x,y,z axis were 2.00,3.25,and 2.88 cm,respectively,which were0.73,1.74,and 1.50 cm after correction,reduced by 1.27,1.51,and 1.38 cm,respectively.Conclusion:IGRT could effectivly guarantee the accuracy of IMRT of the patients with rectal cancer by reducing the systematic errors and position errors.
出处
《吉林大学学报(医学版)》
CAS
CSCD
北大核心
2016年第6期1226-1229,共4页
Journal of Jilin University:Medicine Edition
基金
吉林省卫生厅科研基金资助课题(20150204058YY)
关键词
直肠肿瘤
调强放疗
图像引导放疗技术
rectal neoplasms
intensity modulated radiation therapy
image-guided radiation therapy technology