Comparison of kilovoltage cone-beam computed tomography with megavoltage projection pairs for paraspinal radiosurgery patient alignment and position verification
Comparison of kilovoltage cone-beam computed tomography with megavoltage projection pairs for paraspinal radiosurgery patient alignment and position verification
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DOI：
10.1016/j.ijrobp.2008.04.029
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发表时间：
2008-08-01
影响因子：
7
通讯作者：
Yamada, Yoshiya
中科院分区：
文献类型：
--
作者：
Kriminski, Sergey A.;Lovelock, D. Michael;Yamada, Yoshiya
目的：植入金标记物和兆伏（MV）射野成像通常用于高剂量单次放疗治疗椎旁肿瘤的设置验证。我们调查了千伏锥束计算机断层扫描（CBCT）成像的使用是否消除了标记implantation.Methods和材料的需要：符合单次立体定向体部放射治疗条件的椎旁疾病患者被累积到机构审查委员会批准的协议。16名患者均在目标附近植入了基准标记。标记在MV图像上可见。采集每例患者的三个MV图像对（初始、验证和最终），并与参考图像配准。每个MV对都由CBCT扫描补充。CBCT图像配准通过使用排除标记的感兴趣区域最大化互信息来自动执行。根据MV图像确定的校正值与CBCT的校正值进行了比较，并用于实际的患者设置。左右、前后和上下方向CBCT和MV校正之间差异绝对值的平均值和标准差分别为1.0 +/- 0.7、1.0 +/- 0.6和1.0 +/- 0.8 min，分别相应的治疗前和治疗后千伏CBCT图像配准之间的绝对差异分别为0.6 +/- 0.5、0.6 +/- 0.5和1.0 +/- 0.8 mm。结论：在不使用植入标记的情况下使用CBCT发现的设置校正与MV投影上的标记配准一致。CBCT具有其他优势，包括更好的定位精度和强大的自动三维配准，以及消除对侵入性标记植入的需要。我们已采用CBCT对所有单次脊柱旁患者进行了设置。我们的数据还表明，治疗过程中的目标位移是微不足道的。(C)2008年爱思唯尔公司
Purpose: Implanted gold markers and megavoltage (MV) portal imaging are commonly used for setup verification of paraspinal tumors treated with high-dose, single-fraction radiotherapy. We investigated whether the use of kilo-voltage cone-beam computed tomography (CBCT) imaging eliminates the need for marker implantation.Methods and Materials: Patients with paraspinal disease who were eligible for single-fraction stereotactic body radiotherapy were accrued to an institutional review board-approved protocol. Each of 16 patients underwent implantation of fiducial markers near the target. The markers were visible on the MV images. Three MV image pairs were acquired for each patient (initial, verification, and final) and were registered to the reference images. Every MV pair was complemented by a CBCT scan. CBCT image registration was performed automatically by maximizing the mutual information using a region of interest that excluded the markers. The corrections, as determined from the MV images, were compared with these from CBCT and were used for actual patient setup.Results: The mean and standard deviation of the absolute values of the differences between the CBCT and MV corrections were 1.0 +/- 0.7, 1.0 +/- 0.6, and 1.0 +/- 0.8 min for the left-right, anteroposterior, and superoinferior directions, respectively. The absolute differences between the corresponding pre- and post-treatment kilovoltage CBCT image registration were 0.6 +/- 0.5, 0.6 +/- 0.5, and 1.0 +/- 0.8 mm.Conclusion: The setup corrections found using CBCT without the use of implanted markers were consistent with the marker registration on MV projections. CBCT has additional advantages, including better positioning precision and robust automatic three-dimensional registration, as well as eliminating the need for invasive marker implantation. We have adopted CBCT for the setup of all single-fraction paraspinal patients. Our data have also demonstrated that target displacements during treatment are insignificant. (C) 2008 Elsevier Inc.