Impact of maximum Standardized Uptake Value (SUVmax) evaluated by 18-Fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography ((18)F-FDG-PET/CT) on survival for patients with advanced renal cell carcinoma: a preliminary report

BACKGROUND: In this era of molecular targeting therapy when various systematic treatments can be selected, prognostic biomarkers are required for the purpose of risk-directed therapy selection. Numerous reports of various malignancies have revealed that 18-Fluoro-2-deoxy-D-glucose ((18)F-FDG) accumulation, as evaluated by positron emission tomography, can be used to predict the prognosis of patients. The purpose of this study was to evaluate the impact of the maximum standardized uptake value (SUVmax) from 18-fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography ((18)F-FDG PET/CT) on survival for patients with advanced renal cell carcinoma (RCC). METHODS: A total of 26 patients with advanced or metastatic RCC were enrolled in this study. The FDG uptake of all RCC lesions diagnosed by conventional CT was evaluated by (18)F-FDG PET/CT. The impact of SUVmax on patient survival was analyzed prospectively. RESULTS: FDG uptake was detected in 230 of 243 lesions (94.7%) excluding lung or liver metastases with diameters of less than 1 cm. The SUVmax of 26 patients ranged between 1.4 and 16.6 (mean 8.8 ± 4.0). The patients with RCC tumors showing high SUVmax demonstrated poor prognosis (P = 0.005 hazard ratio 1.326, 95% CI 1.089-1.614). The survival between patients with SUVmax equal to the mean of SUVmax, 8.8 or more and patients with SUVmax less than 8.8 were statistically different (P = 0.0012). This is the first report to evaluate the impact of SUVmax on advanced RCC patient survival. However, the number of patients and the follow-up period were still not extensive enough to settle this important question conclusively. CONCLUSIONS: The survival of patients with advanced RCC can be predicted by evaluating their SUVmax using (18)F-FDG-PET/CT. (18)F-FDG-PET/CT has potency as an "imaging biomarker" to provide helpful information for the clinical decision-making.