负压真空气垫对精确放疗体位固定的影响

目的：探讨负压真空气垫固定技术在肿瘤精确放疗中的临床应用价值及存在的问题。方法：采用真空气垫体住固定技术，利用激光线标出真空袋与身体之间的关系，在患者的相对应部位和真空袋作连线标记，以便患者体住重复。在放疗摆住投照实施前后，用射野标尺测量验证射野前后的靶区各点的移动情况，并进行比较。结果：根据真空气垫标记摆位，患者体住重复性误差〈2mm。患者在0°位置摆位误差〈2mm。验证适形照射野在模拟机下灯光野深度在治疗计划所给深度的平均误差在2-3mm以内。结论：在开展肿瘤精确放疗过程中，用真空气垫固定体位方法的偏差幅度均明显减少，其临床应用价值显而易见。

Effect of Negative Pressure Vacuum Air Cushion in Precise Radiotherapy

Objective To discuss the clinical value and existing problems of the fixation technology of negative pressure vacuum bag in tumor precise radiotherapy. Methods The fixation technology of vacuum bag was utilized. The relations between the vacuum-bag and the body were marked by laser beam. The corresponding parts in the patient were linked with vacuum-bag by marks for the repetition of patient＇s body posture. The confirmation method was used to compare the target areas measured by radiation field scale before and after the body position projection. Results The repeatability errors of patient＇s body posture was not more than 2 mm. The position error at 0° was not more than 2 mm. The average error between the light depth of the suitable shape under the simulator to the treatment plan was 2-3mm. Conclusion It is indicated that in the development of tumor precise radiotherapy process, errors are obviously reduced by using the vacuum air cushion to fix body posture. This method should be applied widely for its high clinical value.