Correlation between internal fiducial tumor motion and external marker motion for liver tumors imaged with 4D-CT
Correlation between internal fiducial tumor motion and external marker motion for liver tumors imaged with 4D-CT
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DOI：
10.1016/j.ijrobp.2006.10.007
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发表时间：
2007-02-01
影响因子：
7
通讯作者：
Krishnan, Sunil
中科院分区：
文献类型：
--
作者：
Beddar, A. Sam;Kainz, Kristofer;Krishnan, Sunil
目的：我们研究了8例接受基于呼吸的计算机断层扫描（四维CT [4D-CT]）手术的患者植入肝脏的外部标记物与内部基准运动之间的相关性。方法与材料：内基准为金种子，长3毫米，直径1.2毫米。四名患者每人植入了一个基准，另外四名患者植入了三个基准。外部标记是一个塑料盒，是实时位置管理系统（RPM）的一部分，用于跟踪患者的呼吸。每位患者接受标准螺旋CT扫描，然后进行时间相关CT图像采集（4D-CT）。将4D-CT图像分10个阶段重建，覆盖整个呼吸周期。结果：内基准运动以上下方向为主，范围为7.5 ~ 17.5 mm。呼气时外呼吸与内基准运动的相关性最好。对于3个基准点间距最大为3.2 cm的2例患者，基准点的运动相关性较好，而对于基准点间距较宽的2例患者，相关性较差。结论：一般来说，4D-CT成像的内部基准运动与外部标记运动具有良好的相关性。我们已经证明，门控可能在呼吸周期结束时进行得最好。对于基准点不同步移动的患者，应特别注意门控，因为仅针对正确的呼吸振幅并不能保证整个肿瘤体积在治疗范围内。(c) 2007爱思唯尔公司
Purpose: We investigated the correlation between the motions of an external marker and internal fiducials implanted in the liver for 8 patients undergoing respiratory-based computed tomography (four-dimensional CT [4D-CT]) procedures.Methods and Materials: The internal fiducials were gold seeds, 3 rum in length and 1.2 mm in diameter. Four patients each had one implanted fiducial, and the other four had three implanted fiducials. The external marker was a plastic box, which is part of the Real-Time Position Management System (RPM) used to track the patient's respiration. Each patient received a standard helical CT scan followed by a time-correlated CT-image acquisition (4D-CT). The 4D-CT images were reconstructed in 10 separate phases covering the entire respiratory cycle.Results: The internal fiducial motion is predominant in the superior-inferior direction, with a range of 7.5-17.5 mm. The correlation between external respiration and internal fiducial motion is best during expiration. For 2 patients with their three fiducials separated by a maximum of 3.2 cm, the motions of the fiducials were well correlated, whereas for 2 patients with more widely spaced fiducials, there was less correlation.Conclusions: In general, there is a good correlation between internal fiducial motion imaged by 4D-CT and external marker motion. We have demonstrated that gating may be best performed at the end of the respiratory cycle. Special attention should be paid to gating for patients whose fiducials do not move in synchrony, because targeting on the correct respiratory amplitude alone would not guarantee that the entire tumor volume is within the treatment field. (c) 2007 Elsevier Inc.