胸部肿瘤患者放疗体位固定技术探讨

Exploration of position fixation technique in chest tumor radiotherapy

目的:探讨胸部肿瘤患者两种不同体位固定技术对提高治疗重复摆位精度的影响。方法:30例胸部肿瘤放疗患者随机分为两组,一组采用真空负压袋固定体位;另一组采用低温热塑体膜固定体位。分别在模拟定位机和电子直线加速器下拍摄模拟定位片和射野验证片,以模拟定位片上射野中心为坐标,测量并计算出两射野中心点在X轴、Y轴、Z轴上的重复摆位误差大小。结果:两组射野中心点在X轴方向上摆位误差分别为(1.37±1.31)mm和(1.35±1.29)mm(P>0.05)、Y轴方向上摆位误差分别为(1.33±1.14)mm和(1.26±1.12)mm(P>0.05)、Z轴方向上摆位误差分别为(2.17±1.54)mm和(1.47±1.32)mm(P<0.01)。结论:胸部肿瘤放射治疗采用热塑体膜固定技术有助于体位的固定,减少摆位误差,提高患者治疗摆位的精确度。

Objective To explore the effects of two different position fixing methods on the precision of reposition in patients with chest tumor receiving radiotherapy. Methods Thirty cases with chest tumor receiving radiotherapy were randomly divided into two groups： vacuum cushion fixed position group and low-temperature thermoplastic membrane fixed position group. Simulation films and portal verification films under the simulator and the electron linear accelerator were separately photographed. The chip beam center was positioned for the coordinates in simulation films, and the deviation of beam center in the X-axis, Y-axis, and Z-axis were calculated. Results The deviation distance with beam center in the X-axis, Y-axis, and Z-axis in the vacuum cushion group and thermoplastic membrane group were （1.37 ＋ 1.31） mm vs. （1.35 ＋ 1.29） mm （P 〉 0.05）, （1.33 ＋ 1.14） mm vs. （1.26 ＋ 1.12） mm （P 〉 0.05）, and （2.17 ＋ 1.54） mm vs. （1.47 ＋_ 1.32） mm （P 〈 0.01）, respectively. Conclusion Position fixation with thermoplastic membrane in radiotherapy is better than vacuum cushion for chest tumor, which can reduce position deviation of the pendulum, so as to enhance the treatment positioning accuracy degrees.