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

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 18F-FDG PET/CT. The impact of SUVmax on patient survival was analyzed prospectively.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.The survival of patients with advanced RCC can be predicted by evaluating their SUVmax using 18F-FDG-PET/CT. 18F-FDG-PET/CT has potency as an "imaging biomarker" to provide helpful information for the clinical decision-making.Renal cell carcinoma (RCC) accounts for 3% of all adult cancers [1]. Approximately 30% of patients are diagnosed with metastases and an additional 20-40% of patients develop metastases after radical nephrectomy with curative intent [2,3]. The outcome of patients with metastatic RCC is poor, with a median survival time of 10 to 21 months [4,5]Classical cytokine therapies have been the only systematic treatments available for advanced RCC for a long time [6-9]. The oncogenic mechanism of RCC has been elucidated and agents that target relevant biological pathways have been investigated. Multiple tyrosine kinase inhibitors (multiple TKIs) targeting vascular endothelial growth factor receptor (VEGFR) such as sunitinib and sorafenib have revolutionized the treatment of RCC [10,11]. Although mammalian tar