FDG PET/CT as a survival prognostic factor in patients with advanced renal cell carcinoma

Accurate prediction of the outcome of molecular target-based treatment in advanced renal cell carcinoma (RCC) is an important clinical problem. Positron emission tomography/computed tomography using [18F]-2-fluoro-2-deoxyglucose (FDG PET/CT) is a noninvasive tool for the assessment of glucose accumulation which can be a marker of the biological characteristics of the tumor. In this paper, we assess FDG PET/CT as a survival prognostic marker in patients with advanced RCC. The study included 121 patients treated in the years 2011-2016 with a diagnosis of advanced renal cell carcinoma (stage IV, multifocal metastases in all patients). Assessment using FDG PET/CT was conducted by measuring the maximum standard uptake value (SUVmax) for the marker used (the highest SUV measurement result for each patient in a single examination). SUVmax measurements were compared with various clinical risk factors used as prognostic markers. The median follow-up period was 19 months (ranging from 3 to 61 months). SUVmax measurements in all patients ranged from 1.3 to 30.0 (median 6.9). Higher SUVmax was correlated with poorer prognosis. Multi-way analysis with standard risk factors revealed that SUVmax was an independent factor for overall survival (OS; p < 0.003, hazard ratio 1.312, 95% CI 1.147-1.346). For SUVmax < 7.0, median OS was 32 months. For 7.0 ≤ SUVmax < 12.0, median OS was 12.5 months. For SUVmax ≥ 12.0, median OS was 10 months. The differences were statistically significant. A preliminary SUVmax assessment conducted using FDG PET/CT can provide information useful in the prediction of survival of patients with advanced RCC.