Evaluation of renal cell carcinoma histological subtype and fuhrman grade using ¹⁸F-fluorodeoxyglucose-positron emission tomography/computed tomography

We evaluated ¹⁸F-fluorodeoxyglucose (FDG) uptake by renal cell carcinomas (RCCs) to determine whether different histological subtypes and Fuhrman grades can be distinguished. We retrospectively reviewed the records and maximum standardised uptake value (SUVmax) of 147 patients with 154 RCCs who underwent FDG-positron emission tomography (PET)/computed tomography (CT) prior to tumour resection. The SUVmax was significantly lower in chromophobe RCC (chRCC) tumours than in clear cell RCC (ccRCC; p = 0.003) and papillary RCC (pRCC; p = 0.034) tumours. The mean tumour SUVmax was 4.58 ± 4.1 (range, 1.29-30.4) for ccRCC, 3.98 ± 1.9 (range, 0.49-6.72) for pRCC, and 1.93 ± 0.9 (range, 0.89-3.41) for chRCC. The SUVmax was not significantly different between the ccRCC and pRCC groups. In ccRCC and pRCC tumours, high-grade tumours had a significantly greater SUVmax (p < 0.001 and p < 0.05) than low-grade tumours by analysis of variance (ANOVA) and the Mann-Whitney U test. In ccRCC, multivariate regression analysis indicated that the SUVmax was a significant indicator of Fuhrman grade. No significant differences in uptake were observed between high- and low-grade chRCC tumours. The SUVmax obtained using FDG-PET/CT may be an important indicator for predicting tumour grade in ccRCC and pRCC. (orig.)