2D/3D image fusion for accurate target localization and evaluation of a mask based stereotactic system in fractionated stereotactic radiotherapy of cranial lesions
2D/3D image fusion for accurate target localization and evaluation of a mask based stereotactic system in fractionated stereotactic radiotherapy of cranial lesions
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DOI：
10.1118/1.2392605
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发表时间：
2006-12-01
期刊：
影响因子：
3.8
通讯作者：
Movsas, Benjamin
中科院分区：
文献类型：
--
作者：
Jin, Jian-Yue;Ryu, Samuel;Movsas, Benjamin
本研究的目的是评估二维（2D）到三维（3D）图像融合引导的目标定位系统和基于掩膜的立体定向系统在颅脑病变分步立体定向放疗（FSRT）中的准确性。最初为颅外放射外科开发的商用x射线图像引导系统用于颅脑病变的FSRT。通过在不同位置植入八个小的不透射线标记物（BBs）的拟人化头部假体，定量评估定位精度。同时对12例患者的127个部位的kV x线片和MV门静脉片的准确性和临床可靠性进行了定性评价。然后使用图像引导系统作为标准来评估这些患者基于头罩的立体定向系统的总体不确定性和可重复性。幻影研究表明，图像引导目标定位的最大随机误差在每个方向上的95%置信区间为+/- 0.6 mm。系统误差随测量方法的不同而不同。对于kV x射线法，它约为0.4 mm，主要在纵向上。在kV x线和MV门静脉方法之间存在0.5 mm的系统差异，主要是在横向上。患者研究表明，图像引导系统在患者中的准确性与在幻影中的准确性相当。掩膜系统的总体不确定度为+/- 4 mm，重复性为+/- 2.9 mm （95% CI）。研究表明，图像制导系统能够提供精确的目标定位。(c) 2006年美国医学物理学家协会。
The purpose of this study was to evaluate the accuracy of a two-dimensional (2D) to three-dimensional (3D) image-fusion-guided target localization system and a mask based stereotactic system for fractionated stereotactic radiotherapy (FSRT) of cranial lesions. A commercial x-ray image guidance system originally developed for extracranial radiosurgery was used for FSRT of cranial lesions. The localization accuracy was quantitatively evaluated with an anthropomorphic head phantom implanted with eight small radiopaque markers (BBs) in different locations. The accuracy and its clinical reliability were also qualitatively evaluated for a total of 127 fractions in 12 patients with both kV x-ray images and MV portal films. The image-guided system was then used as a standard to evaluate the overall uncertainty and reproducibility of the head mask based stereotactic system in these patients. The phantom study demonstrated that the maximal random error of the image-guided target localization was +/- 0.6 mm in each direction in terms of the 95% confidence interval (CI). The systematic error varied with measurement methods. It was approximately 0.4 mm, mainly in the longitudinal direction, for the kV x-ray method. There was a 0.5 mm systematic difference, primarily in the lateral direction, between the kV x-ray and the MV portal methods. The patient study suggested that the accuracy of the image-guided system in patients was comparable to that in the phantom. The overall uncertainty of the mask system was +/- 4 mm, and the reproducibility was +/- 2.9 mm in terms of 95% CI. The study demonstrated that the image guidance system provides accurate and precise target positioning. (c) 2006 American Association of Physicists in Medicine.