不同X线球管曝光参数和金标数量对射波刀立体定向放疗中金标追踪精度的影响  

The Influence of Different X-Ray Tube Parameters and Number of Fiducials on the Tracking Accuracy in SRT of Cyberknife

作　　者：李君[1] 程程 苏文正 刘昊[1] LI Jun;CHENG Cheng;SU Wenzheng;LIU Hao(Department of Radiation Oncology,Peking University Third Hospital,Beijing 100191,China)

机构地区：[1]北京大学第三医院肿瘤放疗科,北京100191

出　　处：《中国医疗设备》2021年第4期166-168,180,共4页China Medical Devices

摘　　要：目的本研究在特定条件下进行对准质量保证(Alignment Quality Assurance,AQA)检测,通过比较目标追踪总位置精度误差、可信度以及刚性误差,探讨X线球管曝光参数和金标数量对射波刀立体定向放疗中金标追踪精度的影响。方法模拟临床治疗,增加模体厚度并人为引入摆位误差,平移10.0 mm、旋转1.0°。分别在标准(管电压60 kV、管电流50 mA、曝光时间50 ms)与特定(管电压100 kV、管电流100 mA、曝光时间100 ms)两种X线球管成像参数条件下,追踪2、3、4颗金标实施AQA检测,每组重复测量6次,记录总位置精度误差、目标追踪可信度以及刚性误差值,并使用双因素无重复试验方差统计方法分析数据。结果X线球管成像参数一致时,3、4颗金标的总位置精度误差明显小于2颗金标,并且3、4颗金标的刚性误差大于2颗金标,差异均具有统计学意义(P<0.001)。金标追踪颗数相同时,随着X线球管成像参数升高,目标追踪可信度显著增加(P<0.001),刚性误差显著降低(P<0.001)。结论特定条件下,金标追踪数目与X线球管成像参数是实现精准摆位与追踪的重要因素。Objective To discuss the effects of X-ray tube parameters and number of fiducials on the tracking accuracy in stereotactic radiotherapy of cybeknife by comparing the comprehensive position accuracy error,reliability and rigidity error of target tracking in this study,alignment quality assurance(AQA)tests were carried out under specific conditions.Methods To simulate the clinical treatment,the thickness of phantom was increased and artificial positioning error was introduced in 10 mm movement and 1.0°rotation.AQA tests were performed using standard(tube voltage 60 kV,tube current 50 mA,exposure time 50 ms)and specific(tube voltage 100 kV,tube current 100 mA,exposure time 100 ms)X-ray tube imaging parameters with 2,3,4 fiducials.The tests were repeated for 6 times.The position accuracy error,reliability and rigid error of target tracking were recorded,and the data were analyzed by two-factor non-repeated test variance statistical method.Results When the imaging parameters of X-ray tube were consistent,the comprehensive positioning accuracy error of 3,4 fiducials was significantly less than that of 2 fiducials,and the rigidity error of 3,4 fiducials was greater than that of 2 fiducials,the differences were statistically significant(P<0.001).When the number of fiducials were same,with the increase of X-ray tube imaging parameters,the reliability of target tracking increased significantly(P<0.001),the rigidity error decreased significantly(P<0.001).Conclusion Under specific conditions,the number of fiducials and X-ray tube imaging parameters are important factors to achieve accurate positioning and tracking.

关 键 词：射波刀 图像引导 质量保证检测 成像参数 

分 类 号：R730.55[医药卫生—肿瘤]