Guha Siddharth, Ibrahim Abdalla, Geng Pengfei, Wu Qian, Chou Yen, Akin Oguz, Schwartz Lawrence H, Xie Chuan-Miao, Zhao Binsheng
Department of Radiology, Columbia University Irving Medical Center, New York, NY 10032, USA.
Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA.
Tomography. 2025 Mar 19;11(3):36. doi: 10.3390/tomography11030036.
In cancers imaged using contrast-enhanced protocols, such as hepatocellular carcinoma (HCC), formal guidelines rely on measurements of lesion size (in mm) and radiographic density (in Hounsfield units [HU]) to evaluate response to treatment. However, the variability of these measurements across different contrast enhancement phases remains poorly understood. This limits the ability of clinicians to discern whether measurement changes are accurate.
In this study, we investigated the variability of maximal lesion diameter and mean lesion density of HCC lesions on CT scans across four different contrast enhancement phases: non-contrast-enhanced phase (NCE), early arterial phase (E-AP), late arterial phase (L-AP), and portal venous phase (PVP). HCC lesions were independently segmented by two expert radiologists. For each pair of a lesion's scan timepoints, one was selected randomly as the baseline measurement and the other as the repeat measurement. Both absolute and relative differences in measurements were calculated, as were the coefficients of variance (CVs). Analysis was further stratified by both contrast enhancement phase and lesion diameter.
Lesion diameter was found to have a CV of 5.11% (95% CI: 4.20-6.01%). About a fifth of the measurement's relative changes were greater than 10%. Although there was no significant difference in diameter measurements across different phases, there was a significant negative correlation (R = -0.303, -value = 0.030) between lesion diameter and percent difference in diameter measurement. Lesion density measurements varied significantly across all phases, with the greatest relative difference of 47% in the late arterial phase and a CV of 22.84% (21.48-24.20%). The overall CV for lesion density measurements was 26.19% (24.66-27.72%).
Changes in tumor diameter measurements within 10% may simply be due to variability, and lesion density is highly sensitive to contrast timing. This highlights the importance of paying attention to these two variables when evaluating tumor response in both clinical trials and practice.
在使用对比增强方案成像的癌症中，如肝细胞癌（HCC），正式指南依靠测量病变大小（以毫米为单位）和放射密度（以亨氏单位[HU]为单位）来评估治疗反应。然而，这些测量在不同对比增强阶段的变异性仍知之甚少。这限制了临床医生辨别测量变化是否准确的能力。
在本研究中，我们调查了HCC病变在CT扫描上四个不同对比增强阶段的最大病变直径和平均病变密度的变异性：非对比增强期（NCE）、动脉早期（E-AP）、动脉晚期（L-AP）和门静脉期（PVP）。HCC病变由两位放射科专家独立分割。对于病变的每对扫描时间点，随机选择一个作为基线测量，另一个作为重复测量。计算测量的绝对和相对差异以及变异系数（CV）。分析进一步按对比增强阶段和病变直径分层。
发现病变直径的CV为5.11%（95%CI：4.20 - 6.01%）。约五分之一的测量相对变化大于10%。尽管不同阶段的直径测量无显著差异，但病变直径与直径测量百分比差异之间存在显著负相关（R = -0.303，P值 = 0.030）。病变密度测量在所有阶段均有显著变化，动脉晚期的最大相对差异为47%，CV为22.84%（21.48 - 24.20%）。病变密度测量的总体CV为26.19%（24.66 - 27.72%）。
10%以内的肿瘤直径测量变化可能仅仅是由于变异性，并且病变密度对对比剂注射时间高度敏感。这突出了在临床试验和实践中评估肿瘤反应时关注这两个变量的重要性。
