鼻咽癌三维适形放射治疗摆位误差分析

目的通过鼻咽癌三维适形放射治疗的摆位误差分析，提高放射治疗摆位的准确性。方法摆完治疗体位放射治疗前。用慢感光片拍摄射野验正片，找出摆位误差，操作者站于患者的头部方向，将面膜轻压向患者的面部。结果在126人次的测量中，多数患者均能达到治疗体位的标准，部分患者需有修正（激光线偏移，控制在2—4mm）后方可进行治疗。结论将鼻咽癌放射治疗的摆位误差设定在允许围内，并最大程度减少摆位误差是放疗的关键。

Beam Position Error Analysis of Three -dimensional Nasopharyngeal Carcinoma Conformal Radiotherapy

Objective To improve the accuracy of radiotherapy beam position through beam position error analysis of three - di- mensional nasopharyngeal carcinoma conformal radiotherapy. Methods Before positioning the treated object for radiotherapy, a wild verification positive picture was taken with a slow （photographic） plate beam to find the beam position error with the operator standing in the patient＇s head orientation to slightly press the facial mask onto the patients. Result In the measurement of 126 cases, most pa- tients can reach the standm＇d of treating position, but some patients should be revised before conducting the treatment （ excursing the la- ser line, within the control of 2 and 4 ram）. Conclusion Setting the positioning error of nasopharyngeal carcinoma radiotherapy within the allowed scope and minimizing the beam position error are crucial to radiation therapy.