Department of Radiology, Kurume University School of Medicine, 67 Asahi-Machi, Fukuoka, Kurume, 830-0011, Japan.
Education and Research Center for Community Medicine, Faculty of Medicine, Saga University, Saga, Japan.
Jpn J Radiol. 2023 Mar;41(3):302-311. doi: 10.1007/s11604-022-01358-y. Epub 2022 Nov 14.
The purpose of this study was to find useful imaging features on non-contrast-enhanced magnetic resonance imaging (MRI) that can divide patients with thymic epithelial tumor (TET) into clinical stage I-II and III-IV groups under assumption that contrast media are contraindicated.
This retrospective study included 106 patients (median age, 60 years; range, 27-82 years; 62 women) with surgically resected TET who underwent MRI between August 1986 and July 2015. All cases were classified according to the 2015 WHO classification and staged using the eighth edition of the TNM system. Two radiologists independently evaluated 14 categories of MRI findings; the findings in patients with stage I-II were compared with those of patients with stage III-IV using a logistic regression model. Disease-specific survival associated with significant findings was calculated using the Kaplan-Meier method.
Univariate analysis showed that stage III-IV patients were more likely to have tumors with an irregular contour, heterogeneity on T1WI, low-signal intensity on T2WI, irregular border with lung, findings of great vessel invasion (GVI) (hereafter, GVI sign), pericardial thickening/nodule, and lymphadenopathy (all, P < 0.01). On multivariable analysis, only two findings, irregular border between tumor and lung (odds ratio [OR], 272.8; 95% CI 26.6-2794.1; P < 0.001) and positive GVI sign (OR, 49.3; 95% CI 4.5-539.8; P = 0.001) remained statistically significant. Patients with one or both features had significantly worse survival (log-rank test, P < 0.001).
For patients with TET who are unable to receive contrast for preoperative staging, the two image findings of an irregular border between tumor and lung and the positive GVI sign on non-contrast-enhanced MRI could be helpful in determining stage III-IV disease which is associated with a worse survival.
本研究旨在寻找非增强磁共振成像（MRI）上的有用影像学特征，以便在假设对比剂禁忌的情况下，将胸腺瘤（TET）患者分为临床 I-II 期和 III-IV 期。
本回顾性研究纳入了 106 例（中位年龄 60 岁，范围 27-82 岁；62 例女性）接受手术切除的 TET 患者，这些患者于 1986 年 8 月至 2015 年 7 月期间进行了 MRI 检查。所有病例均根据 2015 年 WHO 分类进行分类，并采用第八版 TNM 系统进行分期。两名放射科医生独立评估了 14 项 MRI 表现；使用逻辑回归模型比较 I-II 期患者与 III-IV 期患者的表现。使用 Kaplan-Meier 方法计算与显著发现相关的疾病特异性生存率。
单因素分析显示，III-IV 期患者的肿瘤轮廓不规则、T1WI 不均匀、T2WI 低信号、与肺的边界不规则、大血管侵犯（GVI）表现（以下简称 GVI 征）、心包增厚/结节和淋巴结病的可能性更大（均 P < 0.01）。多变量分析显示，只有两个发现具有统计学意义，即肿瘤与肺之间的边界不规则（优势比 [OR]，272.8；95%置信区间 [CI]，26.6-2794.1；P < 0.001）和 GVI 征阳性（OR，49.3；95% CI，4.5-539.8；P = 0.001）。具有一个或两个特征的患者的生存情况明显更差（对数秩检验，P < 0.001）。
对于无法接受术前分期对比剂的 TET 患者，非增强 MRI 上肿瘤与肺之间的边界不规则和 GVI 征阳性这两个影像学表现有助于确定 III-IV 期疾病，与生存较差相关。
