Magnitude and clinical relevance of translational and rotational patient setup errors: A cone-beam CT study
Magnitude and clinical relevance of translational and rotational patient setup errors: A cone-beam CT study
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DOI：
10.1016/j.ijrobp.2006.02.019
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发表时间：
2006-07-01
影响因子：
7
通讯作者：
Flentje, M
中科院分区：
文献类型：
--
作者：
Guckenberger, M;Meyer, J;Flentje, M
目的：利用星载锥束CT （CB-CT）扫描仪建立体积成像，以评估患者的三维设置误差。方法与材料：本研究纳入24例患者的资料，分析比较209张CB-CT和148张电子门静脉图像的设置误差。研究了旋转误差单独、平移误差单独以及旋转和平移联合误差对靶覆盖和危险器官保留的影响。结果：使用CB-CT扫描仪和电子门静脉成像设备的平移设置误差在70.7%的测量中< 1 mm，在93.2%的测量中< 2 mm。3.7%的盆腔肿瘤、26.4%的胸腔肿瘤和12.4%的头颈部肿瘤的旋转误差为0 ~ 2度；相应的最大旋转误差分别为5度、8度和6度。平移和旋转设置误差的大小之间没有相关性。对于靶体积较长、邻近危险器官的剂量梯度较大的患者，与初始治疗计划相比，平移和旋转误差导致靶覆盖范围大大降低，危险器官的剂量大大增加。结论：CB-CT扫描仪已成功建立用于评估患者设置错误，并在日常临床实践中证明了其可行性。我们的结果表明，旋转误差对选定的接受高精度放疗的患者具有临床意义。(c) 2006爱思唯尔公司
Purpose: To establish volume imaging using an on-board cone-beam CT (CB-CT) scanner for evaluation of three-dimensional patient setup errors.Methods and Materials: The data from 24 patients were included in this study, and the setup errors using 209 CB-CT studies and 148 electronic portal images were analyzed and compared. The effect of rotational errors alone, translational errors alone, and combined rotational and translational errors on target coverage and sparing of organs at risk was investigated.Results: Translational setup errors using the CB-CT scanner and an electronic portal imaging device differed < 1 mm in 70.7 % and < 2 mm in 93.2% of the measurements. Rotational errors > 2 degrees were recorded in 3.7% of pelvic tumors, 26.4% of thoracic tumors, and 12.4% of head-and-neck tumors; the corresponding maximal rotational errors were 5 degrees, 8 degrees, and 6 degrees. No correlation between the magnitude of translational and rotational setup errors was observed. For patients with elongated target volumes and sharp dose gradients to adjacent organs at risk, both translational and rotational errors resulted in considerably decreased target coverage and highly increased doses to the organs at risk compared with the initial treatment plan.Conclusions: The CB-CT scanner has been successfully established for the evaluation of patient setup errors, and its feasibility in day-to-day clinical practice has been demonstrated. Our results have indicated that rotational errors are of clinical significance for selected patients receiving high-precision radiotherapy. (c) 2006 Elsevier Inc.