一种根据标记点结构精确确定放疗原始等中心的方法  

A Method to Accurately Determine the Original Isocenter of Radiotherapy According to the Structure of Marked Points

作　　者：程龙 时飞跃[2] 王敏[2] 秦伟[2] 吴倩倩[1] 蒋红兵[1,3] CHENG Long;SHI Feiyue;WANG Min;QIN Wei;WU Qianqian;JIANG Hongbing(Department of Medical Equipment,Nanjing First Hospital,Nanjing Medical University,Nanjing Jiangsu 210006,China;Radiation Therapy Center,Nanjing First Hospital,Nanjing Medical University,Nanjing Jiangsu 210006,China;Nanjing Emergency Medical Center,Nanjing Jiangsu 210003,China)

机构地区：[1]南京医科大学附属南京医院(南京市第一医院)医疗设备处,江苏南京210006 [2]南京医科大学附属南京医院(南京市第一医院)肿瘤放疗中心,江苏南京210006 [3]南京市急救中心,江苏南京210003

出　　处：《中国医疗设备》2022年第4期90-93,共4页China Medical Devices

基　　金：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)。

摘　　要：目的提出一种根据标记点结构精确确定放疗原始等中心坐标的方法(标记点结构法),分析其与常规方法确定的原始等中心之间的差异。方法选取40例接受放射治疗的胸腹部肿瘤患者,首先使用瓦里安Eclipse治疗计划系统的菜单工具手动勾画患者CT图像左、中、右3个标记点的结构,获取标记点结构的几何中心坐标,然后根据公式计算原始等中心的坐标并将其与常规方法比较,分析左右方向差异ΔX、腹背方向差异ΔY、头脚方向差异ΔZ、总距离差异ΔS与水平倾斜角度θ的值。结果40例患者中,标记点出现在1、2、3层CT图像上的人数分别为11、28、1人。标记点部分出现在2层CT图像的有17例,与常规方法相比,其ΔX、ΔY、ΔZ与ΔS分别为(0.43±0.32)、(0.51±0.29)、(1.16±0.50)、(1.43±0.43)mm;还有11例标记点完整出现在2层CT图像上,其与常规方法相比的ΔZ、ΔS的值分别为(2.18±0.14)、(2.34±0.12)mm,均值超过了2 mm(P<0.05),差异有统计学意义。40例患者的水平倾斜角度θ为0.25°±0.17°。结论标记点结构法能精确确定放疗原始等中心的坐标值,当标记点出现在多层CT图像上时,能够有效弥补常规方法的缺陷。Objective To propose a method to accurately determine the original isocenter coordinates of radiotherapy based on the structure of the marked points(marker structure method),and analyze the difference between it and the original isocenter determined by the conventional method.Methods A total of 40 patients with thoracic and abdominal tumors who received radiotherapy were selected.First,the menu tool of the Varian Eclipse treatment planning system was used to manually outline the structure of the left,middle,and right three marked points on the patient’s CT image,and obtain the geometry of the marked point structure center coordinates.Then the coordinates of the original isocenter were calculated according to the formula and compared with the conventional method to analyze the values of the left and right direction differenceΔX,the abdominal-back direction differenceΔY,the head and foot direction differenceΔZ,the total distance differenceΔS,and the horizontal tilt angleθ.Results Among the 40 patients,the number of marked points on the 1,2,and 3 slice CT images were 11,28,and 1,respectively.In the 17 cases where the marked points incompletely appeared on the 2-slice CT image,the marked point structure method compared with the conventional method,ΔX,ΔY,ΔZ andΔS were(0.43±0.32),(0.51±0.29),(1.16±0.50),(1.43±0.43)mm,respectively;when 11 cases of marked points appeared completely on the 2-slice CT image,the values ofΔZ andΔS were(2.18±0.14)and(2.34±0.12)mm respectively compared with the two methods,the mean value exceeded 2 mm(P<0.05),the difference was statistically significant.For 40 patients,the horizontal tilt angleθwas 0.25°±0.17°.Conclusion The marked point structure method can accurately determine the coordinate value of the original isocenter of radiotherapy.When the marked points appear on the multi-slice CT image,it can effectively make up for the shortcomings of the conventional method.

关 键 词：标记点结构 精确放疗 胸腹部肿瘤 原始等中心 精确定位 

分 类 号：R815[医药卫生—放射医学]