千伏级锥形束CT技术在肿瘤放射治疗中的应用研究  

Application of KV Cone Beam CT in Radiotherapy of Tumors

作　　者：郑倩 方明明[1] 芮燕英 吉维 吴文斌 Zheng Qian;Fang Mingming;Rui YanYing;Ji Wei;Wu Wenbin(Radiotherapy Center,Changzhou Tumor Hospital,Changzhou,Jiangsu 213000)

机构地区：[1]江苏省常州市肿瘤医院,213000

出　　处：《现代医用影像学》2019年第10期2202-2205,共4页Modern Medical Imageology

摘　　要：目的:通过回顾性的分析放疗病人的首次摆位误差数据探讨千伏级锥形束CT在肿瘤放疗计划实施过程中在线修正摆位误差的价值,以及为放疗病人的PTV外放提供参考。方法:选取我科2017年1月至12月放疗病人(其中头颈部112例,胸部253例,腹部56例,盆腔部122例)的首次摆位CBCT验证记录,回顾性的进行数据分析,得到不同部位分次间摆位误差。根据Stroom公式:PTV外放=2∑+0.7σ,计算Margin的横向Lat(x)、纵向Lng(y)、竖向Vrt(z)三维方向的范围。系统误差(∑)用分次间摆位误差的平均值(x)表示,随机误差(σ)用分次间摆位误差的标准差(s)表示,总体摆位误差用系统误差加减随机误差表示即(x±s)。结果:头颈部误差最小,腹盆部其次,胸部误差最大,Lat(x)、Lng(y)、Vrt(z)三维方向误差较大者和出现误差较大的频率均发生在Lng(y)方向上。左右,头脚,前后PTV外放头颈部分别为2.73mm,3.56 mm,3.58 mm,胸部分别为4.12mm,7.11 mm,4.10 mm,腹部分别为3.35mm,6.01 mm,3.67 mm,盆腔分别为3.29mm,6.59 mm,3.83 mm。结论:千伏级锥形束CT技术能有效减小分次间摆位误差,为精确放疗的实施提供技术保障。为本放疗中心不同部位肿瘤患者PTV外放提供参考依据,检验放疗相关设备的精度。Objective:To explore the value of KV cone beam CT in correcting positioning errors on-line during the implementation of cancer radiotherapy plan by retrospective analysis of the first positioning error data of patients undergoing radiotherapy, and to provide reference for PTV external radiation of patients undergoing radiotherapy.Methods:CBCT validation records of the first placement of radiotherapy patients in our department from January to December 2017(including 112 cases of head and neck, 253 cases of chest, 56 cases of abdomen and 122 cases of pelvic cavity) were retrospectively analyzed, and the placement errors between different parts were obtained. According to Stroom formula: PTV external amplifier=2∑+0.7σ, the three-dimensional range of Lat(x), Lng(y) and Vrt(z) of Margin is calculated. Systematic error(∑) is expressed by the average value of the interstage placement error(x), random error(σ) is expressed by the standard deviation(s) of the interstage placement error, and the total placement error is expressed by the system error plus or minus the random error, i.e.((x±s).Results:Head and neck errors were the smallest, followed by abdomen and pelvis, and chest errors were the largest. Lat(x), Lng(y), Vrt(z) three-dimensional direction errors occurred in Lng(y) direction. About 2.73 mm, 3.56 mm, 3.58 mm in head and neck, 4.12 mm in chest, 7.11 mm, 4.10 mm in abdomen, 3.35 mm, 6.01 mm, 3.67 mm in abdomen, 3.29 mm, 6.59 mm and 3.83 mm in pelvic cavity.Conclusion:KV cone beam CT can effectively reduce the staging error between stages and provide technical support for the implementation of precise radiotherapy. To provide reference basis for PTV external radiation of cancer patients in different parts of the radiotherapy center, and to test the accuracy of radiotherapy-related equipment.

关 键 词：图像引导放射治疗 千伏级锥形束CT 分次间摆位误差 PTV外放 

分 类 号：R730.55[医药卫生—肿瘤]