DO MAXIMUM INTENSITY PROJECTION IMAGES TRULY CAPTURE TUMOR MOTION?
DO MAXIMUM INTENSITY PROJECTION IMAGES TRULY CAPTURE TUMOR MOTION?
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DOI：
10.1016/j.ijrobp.2008.10.008
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发表时间：
2009-02-01
影响因子：
7
通讯作者：
Papiez, Lech
中科院分区：
文献类型：
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作者：
Park, Kwangyoul;Huang, Long;Papiez, Lech
目的：对于肺癌患者的治疗，内部靶体积通常通过使用借助于四维计算机断层摄影（4D-CT）生成的最大强度投影（MIP）图像来确定。为了检查各种目标运动的MIP的准确性，特别是对不规则移动的目标，我们进行了幻影研究，使用可编程动态肺phantom.Methods和Materials：一个定制的可编程肺幻影被用来模拟不规则的目标运动沿着上下方向。结果：对于所有具有恒定幅度和周期的规则周期性靶运动，测量的MIP靶点沿上下方向沿着的运动范围与真实的靶点运动范围相差2-3 mm。对于具有不同幅度和周期的不规则目标运动，在某些情况下，测量的MIP目标跨度系统地低于目标运动的真实的范围超过1 cm。MIP测量的目标跨度和真实的目标跨度之间的差异随着目标移动速度的增加而减小。我们将这些差异与商业4D-CT目前的重建算法是基于相位binning.Conclusions的事实：根据我们的体模测量，MIP准确地反映了目标运动的范围，定期tar-get运动。然而，当目标运动的幅度和周期不规则时，它通常低估了目标运动的范围。使用MIP的临床内部靶体积确定需要谨慎，特别是当存在呼吸不规则时。(C)2009 Elsevier Inc.
Purpose: For the treatment of patients with lung cancer, internal target volume frequently is determined by using maximum intensity projection (MIP) images generated by means of four-dimensional computed tomography (4D-CT). To check the accuracy of MIPs for various target motions, especially for targets moving irregularly, we performed phantom studies using a programmable dynamic lung phantom.Methods and Materials: A custom-built programmable lung phantom was used to simulate irregular target motions along the superior-inferior direction. After scanning in helical mode using 4D-CT, reconstructed phase and MIP images were imported into the Pinnacle 8.0 treatment planning system for image analysis.Results: For all regular periodic target motions with constant amplitude and period, the measured MIP target span along the superior-inferior direction was accurate within 2-3 mm of the real target motion span. For irregular target motions with varying amplitudes and periods, the measured MIP target span systematically underrepresented the real range of target motion by more than 1 cm in some cases. The difference between measured MIP target span and real target span decreased as the target moved faster. We associate these discrepancies with the fact that current reconstruction algorithms of commercial 4D-CT are based on phase binning.Conclusions: According to our phantom measurements, MIP accurately reflects the range of target motion for regular tar-get motion. However, it generally underestimates the range of target motion when the motion is irregular in amplitude and periodicity. Clinical internal target volume determination using MIP requires caution, especially when there is breathing irregularity. (C) 2009 Elsevier Inc.