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

ABSTRACT

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.