Department of Diagnostic Radiology, Queen Elizabeth II Health Sciences Centre and Dalhousie University, 1276 S Park St, Victoria Bldg, Rm 307, Halifax, NS B3H 2Y9, Canada.
Department of Diagnostic Radiology, McGill University Health Centre, Montreal General Hospital Site, Montreal, QC, Canada.
AJR Am J Roentgenol. 2022 Nov;219(5):793-803. doi: 10.2214/AJR.22.27378. Epub 2022 Jun 1.
The clear cell likelihood score (ccLS) has been proposed for the noninvasive differentiation of clear cell renal cell carcinoma (ccRCC) from other renal neoplasms on multiparametric MRI (mpMRI), though further external validation remains needed. The purpose of our study was to evaluate the diagnostic performance and interreader agreement of the ccLS version 2.0 (v2.0) for characterizing solid renal masses as ccRCC. This retrospective study included 102 patients (67 men, 35 women; mean age, 56.9 ± 12.8 [SD] years) who underwent mpMRI between January 2013 and February 2018, showing a total of 108 (≥ 25% enhancing tissue) solid renal masses measuring 7 cm or smaller (83 cT1a [≤ 4 cm] and 25 cT1b [> 4 cm and ≤ 7 cm]), all with a histologic diagnosis. Three abdominal radiologists independently reviewed the MRI examinations using ccLS v2.0. Median reader sensitivity, specificity, and accuracy were computed for predicting ccRCC by ccLS of 4 or greater, and individual reader AUCs were derived. The percentage of masses that were ccRCC was calculated, stratified by ccLS. Interobserver agreement was assessed by the Fleiss kappa statistic. The sample included 45 ccRCCs (34 cT1a, 11 cT1b), 30 papillary renal cell carcinomas (RCCs), 13 chromophobe RCCs, 14 oncocytomas, and six fat-poor angiomyolipomas. Median reader sensitivity, specificity, and accuracy for predicting ccRCC by ccLS of 4 or greater were 85%, 82%, and 83% among cT1a masses and 82%, 100%, and 92% among cT1b masses. The three readers' AUCs for predicting ccRCC by ccLS for cT1a masses were 0.90, 0.84, and 0.89 and for cT1b masses were 0.99, 0.97, and 0.92. Across readers, the percentage of masses that were ccRCC among cT1a masses was 0%, 0%, 20%, 68%, and 93% for ccLS of 1, 2, 3, 4, and 5, respectively; among cT1b masses, the percentage of masses that were ccRCC was 0%, 0%, 32%, 90%, and 100% for ccLS of 1, 2, 3, 4, and 5, respectively. Interobserver agreement among cT1a and cT1b masses for ccLS of 4 or greater was 0.82 and 0.83 and for ccLS of 1-5 overall was 0.65 and 0.62, respectively. This study provides external validation of the ccLS, finding overall high measures of diagnostic performance and interreader agreement. The ccLS provides a standardized approach to the noninvasive diagnosis of ccRCC by MRI.
清晰细胞可能性评分 (ccLS) 已被提议用于在多参数 MRI (mpMRI) 上对透明细胞肾细胞癌 (ccRCC) 与其他肾肿瘤进行无创鉴别，尽管仍需要进一步的外部验证。本研究的目的是评估 ccLS 版本 2.0 (v2.0) 对作为 ccRCC 的实性肾脏肿块进行特征描述的诊断性能和读者间一致性。这项回顾性研究纳入了 102 名患者（67 名男性，35 名女性；平均年龄 56.9 ± 12.8 [SD] 岁），他们在 2013 年 1 月至 2018 年 2 月期间接受了 mpMRI 检查，总共显示 108 个（≥ 25% 增强组织）实性肾脏肿块，直径均小于 7 cm（83 个 cT1a [≤ 4 cm] 和 25 个 cT1b [> 4 cm 和 ≤ 7 cm]），均有组织学诊断。三位腹部放射科医生使用 ccLS v2.0 独立评估 MRI 检查。计算了 ccLS 为 4 或更高时预测 ccRCC 的中位数读者敏感性、特异性和准确性，并得出了各个读者的 AUC。按 ccLS 分层计算 ccRCC 肿块的百分比。通过 Fleiss kappa 统计量评估观察者间一致性。该样本包括 45 个 ccRCC（34 个 cT1a，11 个 cT1b）、30 个乳头状肾细胞癌（RCC）、13 个嫌色细胞 RCC、14 个嗜酸细胞瘤和 6 个乏脂性血管平滑肌脂肪瘤。ccLS 为 4 或更高时预测 cT1a 肿块 ccRCC 的中位数读者敏感性、特异性和准确性分别为 85%、82%和 83%，预测 cT1b 肿块的为 82%、100%和 92%。三位读者预测 cT1a 肿块的 ccRCC 的 AUC 分别为 0.90、0.84 和 0.89，预测 cT1b 肿块的 AUC 分别为 0.99、0.97 和 0.92。在读者间，cT1a 肿块中 ccLS 为 1、2、3、4 和 5 的 ccRCC 肿块的百分比分别为 0%、0%、20%、68%和 93%；cT1b 肿块中 ccLS 为 1、2、3、4 和 5 的 ccRCC 肿块的百分比分别为 0%、0%、32%、90%和 100%。cT1a 和 cT1b 肿块的 ccLS 为 4 或更高的观察者间一致性分别为 0.82 和 0.83，ccLS 为 1-5 的观察者间一致性分别为 0.65 和 0.62。本研究为 ccLS 提供了外部验证，发现其具有总体较高的诊断性能和读者间一致性。ccLS 为 MRI 对 ccRCC 的无创诊断提供了一种标准化方法。
