Objective Determination of the bulk film fixed different markers in thoracic, abdominal radiotherapy positioning precision and bias. Methods On the somatic membrane fenestration and body membrane fenestration fixation in 200 cases of thoracic, abdominal radiotherapy patients, using CT reset target center level graph center and TPS-system target center level graph center point is measured relatively; using a linear accelerator irradiation center portal verification film and TPS program system for the generation of standard and center field digital image reconstruction ( DRR ) were compared to patients, and place a horizontal axis (X) , a longitudinal axis ( Y ) , before and after the shaft (Z) deviation measurement. Results Somatic membrane without fenestration markers fixed in patients with CT reset target center level chart center point X, Y, Z axis deviation mean respectively (1.6 ±0.8) mm, (4 ±1.2) mm, (3. 6 ±1.2) mm; body membrane fenestration markers and skin at the same time marking method for patients with fixed CT reset the target center level chart center point X, Y, Z axis deviation mean respectively ( 0. 4 ± 0. 6) mm, (2 ± 0. 8 ) mm, ( 2 ± 0. 6) mm. Somatic membrane without fenestration marker fixation, and center field verification film center, such as X, Y,Z axis deviation mean respectively (2 ±1.8) mm, (4. 6 ±1.7) mm, (3. 8 ±1.4) mm; body membrane fenestration markers and skin at the same time marker fixation treatment, and center field verification film such as X, Y, Z axis center of the average deviations were (0. 6 ± 0. 9) mm, (2. 2 ± 1. 4) mm, (2 ± 0. 8) mm. Conclusion Thoracic, abdominal tumor radiotherapy using body membrane fenestration markers fixed patients can significantly reduce the position error, improve the positioning accuracy,precise radiotherapy to quality assurance.%目的 确定体膜固定不同标记法在胸、腹部放疗时的摆位精度和偏差.方法 对用体膜开窗法与体膜不开窗法固定200例胸、腹部放疗的患者,使用CT复位的靶区中心层面图中心点与TPS-计划系统的靶区中心层面图中心点进行测量比较;使用直线加速器照射的等中心射野验证片与TPS-计划系统生成的标准等中心射野数字重建图像(DRR)进行比较,并对患者摆位横轴(X)、纵轴(Y)、前后轴(Z)的偏差进行测量.结果 体膜未做开窗标记固定患者CT复位的靶区中心层面图中心点X,Y、Z轴的平均偏差分别为(1.6±0.8)ram、(4.0±1.2)mm、(3.6±1.2)mm;体膜开窗标记和皮肤上同时标记法固定患者CT复位的靶区中心层面图中心点X、Y、Z轴的平均偏差分别为(0.4±0.6)mm、(2±0.8)mm、(2±0.6)mm.体膜未做开窗标记固定治疗时,等中心射野验证片的等中心X、Y、Z轴的平均偏差分别为(2.0±1.8)mm、(4.6±1.7)mm、(3.8±1.4)mm;体膜开窗标记和皮肤上同时标记法固定治疗时,等中心射野验证片的等中心X、Y、Z轴的平均偏差分别为(0.6±0.9)mm、(2.2±1.4)mm、(2.0±0.8)mm.结论 胸、腹部肿瘤放疗时采用体膜开窗标记固定患者可明显降低摆住误差,提高摆位精度,为精确放疗的实现提供质量保障.
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