Lesion Size and Iodine Quantification to Distinguish Low-Grade From High-Grade Clear Cell Renal Cell Carcinoma Using Dual-Energy Spectral Computed Tomography.

Objective: The aim of this study was to assess the utility of lesion size and iodine quantification using dual-energy spectral computed tomography to distinguish between low-grade and high-grade clear cell renal cell carcinomas (ccRCCs).
Methods: Spectral parameters of 75 patients with pathologically proven ccRCCs who underwent preoperative dual-energy spectral computed tomography examinations were divided into low-grade and high-grade groups. Independent sample t test, receiver operating characteristic curve analysis, and Spearman rank correlation were analyzed.
Results: The lesion size was significantly smaller, and spectral parameters were significantly higher in the low-grade ccRCC. The significant correlation (r = -0.412, P < 0.001) by the Spearman rank correlation was between the normalized iodine concentration and lesion size. The receiver operating characteristic analysis demonstrated that 0.710 was the optimal cutoff value, which yielded the following: sensitivity, 97.6%; specificity, 97.1%; positive predictive value, 97.6%; negative predictive value, 97.1%; and accuracy, 97.3%.
Conclusions: Iodine quantification can play an important role in distinguishing low-grade from high-grade ccRCC.