基于红外定位系统放疗实时摆位预警系统的摆位数据误差统计

目的:利用红外定位系统（OPS）放疗实时摆位预警系统，对放疗摆位累积产生的海量数据，进行与设备性能及体态体姿相关的误差统计与监测，进而实时对摆位进行指导。方法:首先选取264例腹部癌症摆位数据、195例头颈部癌症摆位数据以及186例头部癌症摆位数据；然后搭建归一转换系统，量化标注不同摆位方法产生的不同摆位结果及差异，将现有的摆位结果数据统一转换到一个坐标系下；最后基于放疗摆位累积产生的海量数据，开发模型预警系统，实时监控等中心注册、相机移动、激光线偏移、体膜变形以及锥形束CT本身机械问题5种摆位误差。结果:OPS放疗实时摆位预警系统能够实时监控摆位数据，在腹部264例摆位数据中，5种误差分别为5、1、11、4、7例；在头颈部195例摆位数据中，5种误差分别为13、4、40、0、27例；在头部186例摆位数据中，5种误差分别为10、3、25、0、19例。结论:OPS放疗实时摆位预警系统能较为准确实时预警摆位质量和摆位精度，当摆位出现较大误差时，该系统能够迅速报警，及时指出摆位存在的问题，第一时间提醒、纠正存在的问题。

Statistical analysis of positioning errors based on OPS radiotherapy real-time positioning early warning system

Abstract: Objective To analyze and monitor the errors related to equipment performance and posture by OPS radiotherapy real-time positioning early warning system based on the massive data accumulated by radiotherapy positioning, thereby guiding the positioning in real time. Methods The positioning data in the study were selected from 264 cases of abdominal cancer, 195 cases of head and neck cancer and 186 cases of head cancer. A normalization conversion system was build to quantify and label different positioning results and differences produced by different positioning methods, and then to convert the existing positioning results to a coordinate system. Finally, based on the massive data generated by radiotherapy positioning, an early warning system was developed for the real-time monitoring of 5 kinds of positioning errors which were caused by isocenter registration, camera movement, laser line deviation, body membrane deformation or CBCT mechanical problems. Results The OPS radiotherapy real-time positioning early warning system could monitor the positioning data in real time. The numbers of cases with 5 kinds of positioning errors were 5, 1, 11, 4 and 7 among 264 cases of abdominal cases, 13, 4, 40, 0 and 27 among 195 cases of head and neck cancer, and 10, 3, 25, 0 and 19 among 186 cases of head cancer. Conclusion OPS radiotherapy real-time positioning early warning system can provide more accurate real-time early warning of the quality and accuracy of the positioning. When there is a large positioning error, the system can quickly alarm, point out the problems existing in the positioning in time, and remind and correct it immediately.