应用模拟机对头颈肿瘤适形调强放疗进行位置校准探讨

摘要

目的:应用模拟定位机对头颈肿瘤适形调强放疗进行位置校准.方法:应用模拟机对36例头颈肿瘤适形调强放疗进行位置校准后拍摄校准片,放疗前在加速器上同一体位再摄验证片1次.选择典型骨性标志作为对比参考点,模拟机校准片和加速器验证片分别与来自Pinnacle3治疗系统中的数字重建影像进行对比,分析等中心在X轴、Y轴、Z轴三个方向上的位移.结果:校准片X轴(左右)、Y轴(头脚)、Z轴(前后)平均误差分别为(0.72±0.57)、(0.41±0.41)、(0.86±0.65)mm;加速器验证片X轴、Y轴、Z轴平均误差分别为(0.77±0.58)、(0.49±0.44)、(0.84±0.62)mm,2组差异无统计学意义(P>0.05).结论:应用模拟机进行位置校准可以减少定位、摆位中的误差,是一种有效、便捷的位置验证方法.%Objective: To evaluate the value of position verification in intensity modulated radiation therapy( MRT) by utilizing smulators in head and neck cancer.Methods: Thirty-six cases with head and neck cancer treated with intensity modulated radiotherapy were taken calibration films using smulator for position calibration, and then taken verification films in the same position on the accelerator chip before radiotherapy. Select the typical signs of bone as a reference point for comparison, we analyzed the displacement of iso centers of smulator and accelerator chip calibration and verification finis and the digitally reconstructed mages from Pinnacle3 treatment system in X axis, Y axis, Z axis. Results: Thirty-six patients with head and neck intensitymodulated radiation therapy film X-axis calibration(left),Y-axis( first leg), Z-axis(front) of the average error was(0.72 ±0.57) ,(0.41 ±0.41) ,(0. 86 ±0.65) mm; accelerator verification finis X-axis, Y axis, Z-axis the average error was( 0. 77 ± 0. 58 ) , ( 0. 49 ± 0. 44 ) , ( 0. 84 ± 0. 62 ) mm, the difference between two sets did not statistically significant( P >0. 05). Conclusions: The smulator for position calibration can reduce the positioning error in positioning is an effective and convenient location verification.