Abstract：
OBJECTIVE: The study aimed to validate a method for minimizing phase errors by combining full-length lung 4DCT (f4DCT) scans with shorter tumor-restricted 4DCT (s4DCT) scans. It assessed the feasibility of integrating two scans one covering the entire phantom length and the other focused on the tumor area. The study also evaluated the impact of Maximum Intensity Projection (MIP) volume and imaging dose for different slice thicknesses (2.5mm and 1.25mm) in both full-length and short target-restricted 4DCT scans.
METHODS: The study utilized the Quasar Programmable Respiratory Motion Phantom, simulating tumor motion with a variable lung insert. The setup included a tumor replica and a six-dot IR reflector marker on the breathing platform. The objective was to analyze volume differences in fMIP_2.5mm compared to sMIP_1.25mm within their respective 4D_MIP CT series. This involved varying breathing periods (2.5s, 3.0s, 4.0s, and 5.0s) and longitudinal tumor sizes (6mm, 8mm, and 10mm). The study also assessed exposure time and expected CTDIvol of s4D_2.5mm and s4D_1.25mm for different breathing periods (5.0s to 2.0s) in the sinusoidal wave motion of the six-dot marker on the breathing platform.
RESULTS: Conducting two consecutive 4DCT scans is viable for patients with challenging breathing patterns or when the initial lung tumor scan is in close proximity to the tumor location, eliminating the need for an additional full-length 4DCT. The analysis involves assessing MIP volume, imaging dose (CTDIvol), and exposure time. Longitudinal tumor shifts for 6mm are [16.6-17.2] in fMIP_2.5mm and [16.8-17.5] in sMIP_1.25mm, for 8mm [17.2-18.3] in fMIP_2.5mm and [17.8-18.4] in sMIP_1.25mm, and for 10mm [19-19.9] in fMIP_2.5mm and [19.4-20] in sMIP_1.25mm (p≥ 0.005), respectively.
CONCLUSIONS: The Quasar Programmable Respiratory Motion Phantom accurately replicated varied breathing patterns and tumor motions. Comprehensive analysis was facilitated through detailed manual segmentation of Internal Target Volumes and Internal Gross Target Volumes.
METHODS: The study utilized the Quasar Programmable Respiratory Motion Phantom, simulating tumor motion with a variable lung insert. The setup included a tumor replica and a six-dot IR reflector marker on the breathing platform. The objective was to analyze volume differences in fMIP_2.5mm compared to sMIP_1.25mm within their respective 4D_MIP CT series. This involved varying breathing periods (2.5s, 3.0s, 4.0s, and 5.0s) and longitudinal tumor sizes (6mm, 8mm, and 10mm). The study also assessed exposure time and expected CTDIvol of s4D_2.5mm and s4D_1.25mm for different breathing periods (5.0s to 2.0s) in the sinusoidal wave motion of the six-dot marker on the breathing platform.
RESULTS: Conducting two consecutive 4DCT scans is viable for patients with challenging breathing patterns or when the initial lung tumor scan is in close proximity to the tumor location, eliminating the need for an additional full-length 4DCT. The analysis involves assessing MIP volume, imaging dose (CTDIvol), and exposure time. Longitudinal tumor shifts for 6mm are [16.6-17.2] in fMIP_2.5mm and [16.8-17.5] in sMIP_1.25mm, for 8mm [17.2-18.3] in fMIP_2.5mm and [17.8-18.4] in sMIP_1.25mm, and for 10mm [19-19.9] in fMIP_2.5mm and [19.4-20] in sMIP_1.25mm (p≥ 0.005), respectively.
CONCLUSIONS: The Quasar Programmable Respiratory Motion Phantom accurately replicated varied breathing patterns and tumor motions. Comprehensive analysis was facilitated through detailed manual segmentation of Internal Target Volumes and Internal Gross Target Volumes.
摘要：
目的：该研究旨在通过将全长肺4DCT（f4DCT）扫描与较短的肿瘤限制4DCT（s4DCT）扫描相结合来验证一种最小化相位误差的方法。它评估了整合两个扫描的可行性，一个覆盖整个体模长度，另一个集中在肿瘤区域。该研究还评估了在全长和短目标限制的4DCT扫描中，不同切片厚度（2.5mm和1.25mm）的最大强度投影（MIP）体积和成像剂量的影响。
方法：这项研究利用了类星体可编程呼吸运动模型，用可变的肺插入物模拟肿瘤运动。设置包括在呼吸平台上的肿瘤复制品和六点IR反射器标记。目的是分析fMIP_2.5mm与sMIP_1.25mm在其各自的4D_MIPCT系列内的体积差异。这涉及不同的呼吸周期(2.5s，3.0s,4.0s,和5.0s)和纵向肿瘤大小(6mm，8mm，和10mm）。该研究还评估了呼吸平台上六点标记的正弦波运动中不同呼吸周期（5.0s至2.0s）的s4D_2.5mm和s4D_1.25mm的暴露时间和预期CTDIvol。
结果：对于具有挑战性呼吸模式或初始肺部肿瘤扫描接近肿瘤位置的患者，进行两次连续的4DCT扫描是可行的。消除了对额外的全长4DCT的需要。分析涉及评估MIP体积，成像剂量（CTDIvol），和曝光时间。6mm的纵向肿瘤移位在fMIP_2.5mm中为[16.6-17.2]，在sMIP_1.25mm中为[16.8-17.5]，对于fMIP_2.5mm中的8mm[17.2-18.3]和sMIP_1.25mm中的[17.8-18.4]，对于10mm[19-19.9]的fMIP_2.5mm和[19.4-20]的sMIP_1.25mm（p≥0.005），分别。
结论：类星体可编程呼吸运动模型准确地复制了不同的呼吸模式和肿瘤运动。通过对内部目标卷和内部总目标卷进行详细的手动分割，促进了全面分析。
方法：这项研究利用了类星体可编程呼吸运动模型，用可变的肺插入物模拟肿瘤运动。设置包括在呼吸平台上的肿瘤复制品和六点IR反射器标记。目的是分析fMIP_2.5mm与sMIP_1.25mm在其各自的4D_MIPCT系列内的体积差异。这涉及不同的呼吸周期(2.5s，3.0s,4.0s,和5.0s)和纵向肿瘤大小(6mm，8mm，和10mm）。该研究还评估了呼吸平台上六点标记的正弦波运动中不同呼吸周期（5.0s至2.0s）的s4D_2.5mm和s4D_1.25mm的暴露时间和预期CTDIvol。
结果：对于具有挑战性呼吸模式或初始肺部肿瘤扫描接近肿瘤位置的患者，进行两次连续的4DCT扫描是可行的。消除了对额外的全长4DCT的需要。分析涉及评估MIP体积，成像剂量（CTDIvol），和曝光时间。6mm的纵向肿瘤移位在fMIP_2.5mm中为[16.6-17.2]，在sMIP_1.25mm中为[16.8-17.5]，对于fMIP_2.5mm中的8mm[17.2-18.3]和sMIP_1.25mm中的[17.8-18.4]，对于10mm[19-19.9]的fMIP_2.5mm和[19.4-20]的sMIP_1.25mm（p≥0.005），分别。
结论：类星体可编程呼吸运动模型准确地复制了不同的呼吸模式和肿瘤运动。通过对内部目标卷和内部总目标卷进行详细的手动分割，促进了全面分析。
