红外定位系统（OPS）辅助摆位新技术在肝癌放疗中的应用

目的:研究红外定位系统（optical positioning system,OPS）辅助摆位新技术在肝癌放射治疗中对摆位误差的影响及其在肝癌精确放疗中的应用价值。方法:本研究选取30例肝癌患者，均应用OPS技术辅助摆位。将CBCT扫描作为标准，比较OPS技术和室内激光系统（十字线）在X（左右）、Y（头脚）、Z（面背）三个方向的线性误差；并根据摆位误差折线图分别计算出OPS和十字线的临床摆位一致性百分比。结果:通过OPS摆位在X、Y、Z方向上的摆位误差分别为（2.74±1.27） mm、（3.45±1.17） mm、（2.85±1.11） mm；通过十字线摆位在X、Y、Z方向上的摆位误差分别为（4.37±1.45） mm、（5.79±1.52） mm、（4.27±1.55） mm，各方向对应的P均<0.001。以±5 mm为标准，OPS在三个方向上的临床一致性分别为96.7%、90.0%、98.7%；十字线在三个方向上的临床一致性分别为68.0%、32.7%、72.7%。结论:OPS在肝癌放射治疗定位摆位方面非常有效。作为一种无辐射、低成本、简便快捷的定摆位新技术，OPS比室内激光系统更能提高整体的摆位精度。

Application of OPS-assisted positioning technology in radiotherapy of liver cancer

Objective:To study the influence of the optical positioning system（OPS）-assisted positioning technology on the positioning error in the radiotherapy of liver cancer and its application value in the precise radiotherapy of liver cancer.Methods:In this study,30 patients with liver cancer were selected,and OPS technology was used to assist positioning.Using CBCT scan as the standard,the linear errors of OPS technology with conventional positioning technology（laser line) in the three directions of X（left and right),Y（head and foot),and Z（face and back) were compared.And calculate the clinical setting consistency percentage of OPS and crosshairs respectively was calculated according to the line graph of the positioning error.Results:The positioning errors in the X,Y,and Z directions through OPS were （2.74±1.27) mm,(3.45±1.17) mm,(2.85±1.11) mm,respectively.The positioning errors in X,Y,and Z directions through laser line were （4.37±1.45) mm,(5.79±1.52) mm,(4.27±1.55) mm,and the corresponding P value in each direction was less than 0.001.Taking ±5 mm as the standard,the clinical consistency of OPS in the three directions were 96.7%,90.0%,98.7%.The clinical consistency of the laser line in the three directions were 68.0%,32.7%,72.7%.Conclusion:OPS is very effective in positioning of radiotherapy for liver cancer.As a non-radiation,low-cost,simple and fast positioning technology,OPS can improve the overall positioning accuracy better than indoor laser systems.