摘要
目的:提出一种基于标记点实现放疗患者治疗等中心位置验证的新方法,并进行初步测试。方法:首先,使用木箱模体进行放疗复位的可行性实验。随机产生15组位移数据,对应放疗计划中治疗等中心相对于原始等中心的位置偏移。根据位移数据,借助可移动式激光灯和CT扫描床,在木箱模体上贴两套(每套3只)标记点,分别对应原始等中心和治疗等中心,进行CT扫描。在Eclipse治疗计划系统中,手动确认两个等中心点并得到对应的坐标数据,计算坐标数据之差得到实际位移值。通过比较实际位移实现治疗等中心位置确认。除此之外,尝试使用阈值分割算法实现在患者定位CT图像上自动检测金属标记点,并获取等中心点的坐标值。在木箱实验中,实际位移值与计划位移值的差的绝对值(记为Δd),用于表示治疗等中心的位置精度。使用阈值分割算法检测等中心时得到的偏差值记为Δs。结果:在X(左右)、Y(头脚)和Z(腹背)方向Δd值分别为(0.83±0.37)mm、0(0,0.5)mm和(0.45±0.29)mm;在X、Y、Z方向Δs分别为(0.46±0.22)mm、0(0,0.5)mm、(0.33±0.29)mm;Δs在3个方向上均值均小于2 mm,在临床摆位误差允许范围内。结论:基于标记点验证治疗等中心位置的方法是可行的,本研究为在CT模拟机下进行放疗复位工作提供参考。
Objective To propose a novel method for verifying the isocenter in radiotherapy based on markers and conduct a preliminary test.Methods A feasibility experiment was conducted on wooden box phantom for radiotherapy resetting.Fifteen groups of displacement data were randomly generated,corresponding to the position deviations of the isocenter in the radiotherapy plan relative to the original isocenter.According to each set of displacement data,with the aid of movable lasers and a CT scanning couch,CT scanning was performed with two sets of markers(3 per set)affixed to the phantom which were corresponding to the original and treatment isocenters,respectively.In the Eclipse treatment planning system,the coordinate data of the original and treatment isocenters were manually verified,and the difference of coordinate data was calculated to obtain the actual displacement value.The treatment isocenter position was finally confirmed by comparing with the actual displacement.In addition,the study attempts to use threshold segmentation algorithm to automatically detect metal markers and obtain coordinate values of the original isocenter on patient-positioned CT images.In the wooden box experiment,the absolute value of the difference between the actual displacement value and the planned displacement value(Δd)was used to represent the position accuracy of treatment isocenter,and the deviation value obtained with threshold segmentation algorithm for isocenter detection wasΔs.Results TheΔd in the X(left-right),Y(superior-inferior)and Z(anterior-superior)directions was(0.83±0.37)mm,0(0,0.5)mm and(0.45±0.29)mm,respectively.TheΔs in the X,Y and Z directions was(0.46±0.22)mm,0(0,0.5)mm and(0.33±0.29)mm,respectively.The mean values ofΔs in 3 directions were all lower than 2 mm,within the range of permissible clinical positioning error.Conclusion The method of automatically verifying treatment isocenter position based on markers is feasible,and the study provides a useful reference for radiotherapy resetting using CT simulator.
作者
吕懂霞
王文化
秦伟
王敏
魏晓为
时飞跃
蒋红兵
LÜDongxia;WANG Wenhua;QIN Wei;WANG Min;WEI Xiaowei;SHI Feiyue;JIANG Hongbing(Department of Clinical Medical Equipment,Nanjing First Hospital,Nanjing Medical University,Nanjing 210006,China;Shanghai Datu Medical Technology,Shanghai 200062,China;Tumor Radiotherapy Center,Nanjing First Hospital,Nanjing Medical University,Nanjing 210006,China;Nanjing Emergency Medical Center,Nanjing 210003,China)
出处
《中国医学物理学杂志》
2025年第1期1-6,共6页
Chinese Journal of Medical Physics
基金
国家自然科学基金(81773240)
南京市医学科技发展资金“青年工程”人才培养专项经费资助项目(QRX11033)。
作者简介
吕懂霞,硕士研究生,研究方向:肿瘤放射物理,E-mail:lvdongxia2022@126.com;通信作者:时飞跃,博士,副研究员,研究方向:肿瘤放射物理,E-mail:shifeiyue2013@126.com;通信作者:蒋红兵,高级工程师,研究方向:生物医学工程,E-mail:cmdjhb@126.com。
