探讨全身型真空袋在胸腹部肿瘤放疗体位 固定中的优势

目的∶探讨常规120cm×80cm规格真空袋和全身型180mx80cm规格真空袋在胸腹部肿瘤放射治疗体位固定中的准确性和重复性。方法∶选取在本中心接受治疗的77例胸腹部肿瘤患者，其中使用常规真空袋固定体位的4 例，使用全身型真空袋固定体位的36例，均在螺旋断层治疗机上进行治疗，每次治疗前行兆伏级计算机断层扫描扫描，采集摆位误差数据并进行分析。结果∶与常规真空袋的头脚方向误差（1.67±4.20）mm 和空间三维误差（5.7刀±3.11）mm相比，使用全身型真空袋的头脚方向误差（0.47±3.47）mm和空间三维误差（4.96±2.47）mm均明显减小，差异有统计学意义（P<0.05），但X轴、Z轴和横断面的旋转误差差异无统计学意义（P>0.05）。结论∶在胸腹部肿瘤放疗体位固定中，相比常规型真空袋，全身型真空袋固定体位能在一定程度上减小放疗的摆位误差，提高放疗摆位的精确度。

Advantages of Whole Body Fixed Vacuum Bag in the Immobilization for Radiotherapy of Thoracic and Abdominal Cancer

Objective:To investigate the accuracy of conventional vacuum bag(120 cm x80 cm)and whole body fixed vacuum bag(180 cm x 80 cm)in radiotherapy for thoracic and abdominal cancer.Methods:77 casese of thoracic and abdominal tumor were recruited with 41 using conventional vacuum bag and 36 using whole body fixed vacuum bag.Before tomography,all patients had a megavoltage computed tomography scanning.Setup errors were recorded and analyzed.Results:Compared with conventional vacuum bag,whole body fixed vacuum bag could significantly reduce errorsin the Y-axis directionconventional group:(1.67±4.20)mm,whole body fixed group:(0.47±3.47)mm,P<0.05]and 3D position errorsconventional group:(5.77±3.11)mm,whole body fixed group:(4.96±2.47)mm,P<0.05].No significant differences were found in rotation errors in X-axis,Z-axis and roll direction(P>0.05).Conclusion:In radiotherapy for thoracic and abdominal cancer,whole body fixed vacuum bag helps to reduce setup errors and improve positioning accuracy compared with conventional vacuum bag.