BrainLAB立体定向放射治疗系统辐射等中心误差检测  

Detection of Radiation Isocenter Errors of BrainLAB Stereotactic Radiotherapy System

作　　者：李陆军[1] 钟宇行 覃伟光 卢敏华 Li Lujun;Zhong Yuxing;Qin Weiguang;Lu Minhua(Radiotherapy Technology Area,Wuzhou Red Cross Hospital,Wuzhou Guangxi 543000,China)

机构地区：[1]梧州市红十字会医院放疗技术区,广西梧州543000

出　　处：《医疗装备》2022年第11期9-11,共3页Medical Equipment

摘　　要：目的检测BrainLAB立体定向放射治疗系统辐射等中心误差。方法将自制模体固定在BrainLAB的体位固定架上进行CT扫描,并将扫描图像传输至iPlan RT计划系统进行计划设计,将金属小球设为治疗靶区,以其中心为靶中心,获得摆位坐标。在直线加速器下对模体进行摆位,安装BrainLAB适配器及7.5 mm的圆锥形准直器,并以7.5 mm圆锥形准直器为辐射野,在治疗床和准直器为0°的状态下,分别在机架角为0°、90°、180°及270°时各拍摄1张摆位验证图像;卸下圆锥形准直器,将直线加速器二级准直器的辐射野设置为1 cm×1 cm,以相同的方法获取4张图像;分析立体定向放射治疗等中心误差和直线加速器治疗等中心误差。结果当机架角为0°、90°、180°及270°时,立体定向放射治疗等中心误差分别为0.52、0.19、0.51及0.44 mm,直线加速器治疗等中心误差分别为0.66、0.36、0.51及0.31 mm,两者之间的差值分别为-0.14、-0.17、0.00及0.13 mm。结论应用该研究的方法可快速检测到各种因素导致的误差,使BrainLAB立体定向放射治疗系统辐射等中心误差符合立体定向放射治疗对摆位精度的要求(误差小于1.25 mm),从而确保治疗的精度。Objective The radiation isocenter errors of BrainLAB stereotactic radiotherapy system were detected.Methods The self-made phantom was fixed on the BrainLAB scaffold and scanned by CT.The images of the phantom were transferred to the iPlan RT planning system for designing plan.The small metal ball was set as the target area and its center was taken as the target center,and the positioning coordinates were obtained from the plan.The phantom was positioned under the linear accelerator,the BrainLAB adapter and a 7.5 mm conical collimator were installed,and the 7.5 mm conical collimator was taken as the radiation field,when the couch and collimator were 0°,the positioning verification images were taken when the gantry angles were 0°,90°,180°and 270°respectively;and then the conical collimator was removed,and the radiation field of the secondary collimator of the accelerator was set as 1 cm×1 cm,and the verification images were obtained in the same manner;the isocenter errors of stereotactic radiotherapy and linear accelerator were analyzed.Results When the gantry angles were 0°,90°,180°and 270°respectively,the isocenter errors of stereotactic radiotherapy were 0.52,0.19,0.51 and 0.44 mm,and the isocenter errors of linear accelerator were 0.66,0.36,0.51,and 0.31 mm respectively,the differences between them were-0.14,-0.17,0.00 and 0.13 mm respectively.Conclusion The method put forward in this study can detect the errors caused by various factors quickly,so it can make the radiation isocenter errors of BrainLAB stereotactic radiotherapy system meet the positioning accuracy requirements of stereotactic radiotherapy(error is less than 1.25 mm)and therefore can ensure the accuracy of treatment.

关 键 词：立体定向放射治疗 等中心误差 质量保证 质量控制 精确放射治疗 

分 类 号：R815[医药卫生—放射医学]