放疗体膜参考点放置技巧对胸腹部肿瘤首次摆位的影响

Effect of Placement Techniques of Body Membrane Mark Points on Initial Setup of Thoracic and Abdominal Tumor

目的研究体膜参考点放置技巧对首位摆位通过率及参考点(Mark点)和射野中心(Iso)坐标一致性的影响。方法利用图像工作站测距功能结合放疗科常规设备将实验组"移中心"提前至CT扫描前。对比对照组在首次摆位时Mark点和Iso的空间坐标在患者身体左右方向x、头脚方向y、腹背方向z的一致性,利用EPID首次验证中心时,DRR图像和校野图像在x、y、z方向的摆位误差。结果实验组在x、y、z方向上Mark点与Iso一致性的次数明显多于对照组,差异有统计学意义(P<0.05)。首次摆位误差x、y方向上实验组与对照组比较差异有统计学意义(P<0.05),z方向上两组差异无统计学意义(P>0.05)。结论放疗体膜参考点放置技巧可以减少首次摆位误差,提高Mark点与Iso空间坐标的一致性和首次摆位通过率。

Objective To research the effect of placement techniques of body membrane mark points on the pass rate of initial setup and the consistency between mark points and portal center （Iso） coordinate.Methods The“Offset Center”was ad-vanced in front of CT scan by the ranging capabilities of image workstation combined with the conventional equipment in the de -partment of radiotherapy in the experimental group .The consistency between mark points and Iso spatial coordinates in the direc-tions of x （left and right）,y （head and foot）,and z （front and rear） axes during the initial setup was compared in the control group.The setup errors of DRR images and portal images in the directions of x ,y,and z axes were compared in the initial verifica-tion of the center using EPID .Results The numbers of consistency between mark points and Iso spatial coordinates in the direc -tions of x,y,and z axes in the experimental group were significantly higher than those of the control group ,with statistically signifi-cant differences （P〈0.05）.The initial setup errors were significantly different in the directions of x and y axes between the ex -perimental group and the control group （P〈0.05）,and there had no difference in the direction of z axis （P〉0.05）.Conclu-sion The placement techniques of reference points in body film in radiotherapy could reduce the initial setup errors ,and improve the consistency between mark points and Iso spatial coordinates and the pass rate of initial setup .