真空袋体位固定技术临床应用价值的研究

目的分析体部恶性肿瘤在放射治疗中，真空袋体位固定技术的临床应用价值及存在的问题。方法随机抽取实施体部放疗患者714例(野)，其中使用真空袋固定体位的582例(野)，使用非真空袋固定体位(指用沙袋、胶带等简易固定体位，网膜固定体位除外)的132例(野)，在放疗摆位投照实施前、后用直尺测量灯光野与照射野各点的移动情况进行比较。另抽取56例(野)使用二次抽真空的复形真空袋固定体位的患者，同样用上述方法进行比较。结果用真空袋体位固定者灯光野与照射野的偏差率为6．7％，而用非真空袋体位固定者的为26．5％，用复形真空袋体位固定者的为32．1％。结论真空袋固定体位技术的偏差率明显少于用非真空袋体位固定和二次抽真空复形袋固定的患者，对于半软状态的真空袋须重新制作及到模拟定位机下透视复位方可供临床使用。

Clinical application of vacuum bag immobilization of the trunk in malignant tumor patients

Objective To evaluate the clinical application of vacuum bag imm obilization of thorax and pelvis for patients with malignant tumors. Methods Of 714 patients (fields) chosen randomly, 582(fields)were immobilized with vac uum bag, while the other 132 (fields) used only sand bags, tapes, and other s imp le immobilizing devices. The field movements were measured and compared before and after the setup, along with 56 patients immobilized twice with vacuum bag . Results The variance of movement before and after the setup was 6.7% for patien ts with vacuum bag, while that was 26.5% for patients without the vacuum b ag.It was even 32.1% for patients immobilized twice with vacuum bag. Conclusions The variance of movement decreases significantly with vacuum bag immobilization. I t should be used as frequently as possible. As the variance of movement rises o bviously when vacuum bag is used twice, the semi-soft vacuum bag should b e prepared afresh and checked under the simulator before the second use.