Role of F-FDG-PET in renal tumors: insights from WHO 2022 classification.

The objective of this article is to provide a comprehensive overview of the imaging characteristics of various renal cell tumors using 18F-fluorodeoxyglucose (FDG)-positron emission tomography (PET), based on the latest WHO-2022 classification. Due to the physiological accumulation of FDG in the kidneys, the clinical utility of FDG-PET in the evaluation of renal tumors has traditionally been considered limited. However, recent studies have re-evaluated its potential value. FDG-PET has demonstrated particular utility in detecting metastases and postoperative recurrence of renal cell carcinoma (RCC), as well as in identifying RCC in patients with chronic kidney failure, where FDG excretion into the urinary tract is reduced. Renal tumors are occasionally detected incidentally on FDG-PET, and FDG uptake varies depending on the tumor subtype. Therefore, a comprehensive understanding of these imaging characteristics is clinically important, as it may serve as a valuable guide for subsequent diagnostic evaluations. Furthermore, recent advancements in the development of novel PET tracers hold promise for future applications in the imaging of renal tumors. We believe that the insights gained from this study will contribute to routine diagnostic practice and the planning of future research.