Department of Radiology, Anam Hospital, Korea University College of Medicine, Seoul, South Korea.
Department of Biostatistics, Korea University College of Medicine, Seoul, South Korea.
Abdom Radiol (NY). 2016 Jun;41(6):1160-9. doi: 10.1007/s00261-016-0732-9.
To evaluate the correlation between CT findings and histologic grade of small clear cell renal cell carcinoma (ccRCC).
CT scans of 101 patients with small ccRCC were reviewed independently by two radiologists for tumor size, shape, margin, encapsulation, enhancement pattern, and visual relative enhancement. Enhancement patterns were defined according to the percentage of uniform enhancement [pattern 1, homogeneous (≥90%); pattern 2, relatively homogeneous (≥75 and <90%); and pattern 3, heterogeneous (<75%)]. Quantitative parameters representing attenuation and degree of enhancement were calculated. Histologic grade was classified as low (Fuhrman grade I or II) and high (Fuhrman grade III or IV). CT imaging variables were analyzed using univariate and multivariate analyses.
A total of 63 low-grade and 38 high-grade small ccRCCs were assessed. Low-grade tumors differed from high-grade tumors with respect to enhancement pattern 1 or 2 (p < 0.001 and p < 0.001), smaller size (p = 0.002 and p = 0.001), and lower attenuation on unenhanced scan (p < 0.001 and p = 0.008). In multivariate analysis, enhancement pattern 1 or 2 and low attenuation (≤30 HU) were identified as independent predictors of low-grade ccRCC. Accuracy derived from logistic regression analysis was 79.2% for reader 1 and 70.3% for reader 2.
CT imaging features including tumor attenuation and enhancement pattern can be useful to predict the biologic behavior of small ccRCC for adequate treatment strategy.
评估 CT 表现与小透明细胞肾细胞癌（ccRCC）组织学分级的相关性。
由两名放射科医生独立对 101 例小 ccRCC 患者的 CT 扫描结果进行回顾性分析，评估肿瘤大小、形状、边缘、包膜、强化方式和视觉相对强化程度。根据均匀强化百分比定义强化模式[1 型，均匀（≥90%）；2 型，相对均匀（≥75%且<90%）；3 型，不均匀（<75%）]。计算衰减和强化程度的定量参数。组织学分级分为低级别（Fuhrman 分级 I 或 II）和高级别（Fuhrman 分级 III 或 IV）。使用单变量和多变量分析对 CT 成像变量进行分析。
共评估了 63 例低级别和 38 例高级别小 ccRCC。与高级别肿瘤相比，低级别肿瘤的强化模式为 1 型或 2 型（p<0.001 和 p<0.001）、肿瘤较小（p=0.002 和 p=0.001）、平扫时的衰减值较低（p<0.001 和 p=0.008）。多变量分析显示，强化模式 1 型或 2 型和低衰减值（≤30 HU）是低级别 ccRCC 的独立预测因素。两位读者的逻辑回归分析的准确率分别为 79.2%和 70.3%。
包括肿瘤衰减和强化模式在内的 CT 影像学特征有助于预测小 ccRCC 的生物学行为，以便制定适当的治疗策略。
