Department of Radiology, Massachusetts General Hospital [MGH], Harvard Medical School, Boston, MA, 02114, USA.
Department of Radiology, University of Florida College of Medicine, Gainesville, FL, 32610, USA.
Abdom Radiol (NY). 2017 Jun;42(6):1734-1743. doi: 10.1007/s00261-017-1061-3.
To evaluate whether the Aorta-Lesion-Attenuation-Difference on contrast-enhanced CT can aid in the differentiation of malignant and benign oncocytic renal neoplasms.
Two independent cohorts-an initial (biopsy) dataset and a validation (surgical) dataset-with oncocytomas and chromophobe renal cell carcinomas (chRCC) were included in this IRB-approved retrospective study. A region of interest was placed on the renal mass and abdominal aorta on the same CT image slice to calculate an Aorta-Lesion-Attenuation-Difference (ALAD). ROC curves were plotted for different enhancement phases, and diagnostic performance of ALAD for differentiating chRCC from oncocytomas was calculated.
Seventy-nine renal masses (56 oncocytomas, 23 chRCC) were analyzed in the initial (biopsy) dataset. Thirty-six renal masses (16 oncocytomas, 20 chRCC) were reviewed in the validation (surgical) cohort. ALAD showed a statistically significant difference between oncocytomas and chromophobes during the nephrographic phase (p < 0.001), early excretory phase (p < 0.001), and excretory phase (p = 0.029). The area under the ROC curve for the nephrographic phase was 1.00 (95% CI: 1.00-1.00) for the biopsy dataset and showed the narrowest confidence interval. At a threshold value of 25.5 HU, sensitivity was 100 (82.2%-100%) and specificity was 81.5 (61.9%-93.7%). When tested on the validation dataset on measurements made by an independent reader, the AUROC was 0.93 (95% CI: 0.84-1.00) with a sensitivity of 100 (80.0%-100%) and a specificity of 87.5 (60.4%-97.8%).
Nephrographic phase ALAD has potential to differentiate benign and malignant oncocytic renal neoplasms on contrast-enhanced CT if histologic evaluation on biopsy is indeterminate.
评估对比增强 CT 上的主动脉-病灶衰减差（Aorta-Lesion-Attenuation-Difference，ALAD）能否有助于鉴别良恶性嗜酸细胞瘤性肾肿瘤。
本研究经机构审查委员会批准，回顾性纳入了包含嗜酸细胞瘤和嫌色细胞肾细胞癌（chromophobe renal cell carcinomas，chRCC）的两个独立队列——初始（活检）数据集和验证（手术）数据集。在同一 CT 图像切片上，在肾肿块和腹主动脉上放置感兴趣区以计算 ALAD。绘制不同增强期的 ROC 曲线，并计算 ALAD 鉴别 chRCC 与嗜酸细胞瘤的诊断性能。
在初始（活检）数据集中分析了 79 个肾肿块（56 个嗜酸细胞瘤，23 个 chRCC）。在验证（手术）队列中回顾性分析了 36 个肾肿块（16 个嗜酸细胞瘤，20 个 chRCC）。在肾实质期（p < 0.001）、早期排泄期（p < 0.001）和排泄期（p = 0.029），ALAD 在嗜酸细胞瘤和嫌色细胞之间显示出统计学上的显著差异。活检数据集的 ROC 曲线下面积为 1.00（95%CI：1.00-1.00），置信区间最窄。当阈值为 25.5 HU 时，灵敏度为 100（82.2%-100%），特异性为 81.5（61.9%-93.7%）。当在由独立读者进行测量的验证数据集中进行测试时，AUROC 为 0.93（95%CI：0.84-1.00），灵敏度为 100（80.0%-100%），特异性为 87.5（60.4%-97.8%）。
如果活检的组织学评估不确定，肾实质期 ALAD 有可能在对比增强 CT 上区分良性和恶性嗜酸细胞瘤性肾肿瘤。
