To assess differences in FDG-PET/CT uptake among four subtypes of renal tumors: clear cell RCC (ccRCC), papillary type I and II RCC (pRCC), and oncocytoma.
This retrospective study investigated 33 patients with 98 hereditary renal tumors. Lesions greater than 1 cm and patients with a timeframe of less than 18 months between preoperative imaging and surgery were considered. FDG-PET/CT images were independently reviewed by two nuclear medicine physicians, blinded to clinical information. Volumetric lesion SUVmean was measured and used to calculate a target-to-background ratio respective to liver (TBR). The Shrout-Fleiss intra-class correlation coefficient was used to assess reliability between readers. A linear mixed effects model, accounting for within-patient correlations, was used to compare TBR values of primary renal lesions with and without distant metastasis.
The time interval between imaging and surgery for all tumors had a median of 77 (Mean: 139; Range: 1-512) days. Intra-class reliability of mean TBR resulted in a mean κ score of 0.93, indicating strong agreement between the readers. The mixed model showed a significant difference in mean TBR among the subtypes (p < 0.0001). Pairwise comparison showed significant differences between pRCC type II and ccRCC (p < 0.0001), pRCC type II and pRCC type I (p = 0.0001), and pRCC type II and oncocytoma (p = 0.0016). Furthermore, a significant difference in FDG uptake was present between primary pRCC type II renal lesions with and without distant metastasis (p = 0.023).
pRCC type II lesions demonstrated significantly higher FDG activity than ccRCC, pRCC type I, or oncocytoma. These findings indicate that FDG may prove useful in studying the metabolic activity of renal neoplasms, identifying lesions of highest clinical concern, and ultimately optimizing active surveillance, and personalizing management plans.
Abdominal radiology (New York). 2021 Mar 10 [Epub ahead of print]
Moozhan Nikpanah, Anna K Paschall, Mark A Ahlman, Ali Cahid Civelek, Faraz Farhadi, S Mojdeh Mirmomen, Xiaobai Li, Babak Saboury, Mark W Ball, Maria J Merino, Ramaprasad Srinivasan, Elizabeth C Jones, W Marston Linehan, Ashkan A Malayeri
Radiology and Imaging Sciences, Clinical Center, National Institutes of Health, Bethesda, MD, USA., Duke University School of Medicine, Durham, NC, USA., Division of Nuclear Medicine and Molecular Imaging, Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, USA., Advanced Cardiovascular Imaging Laboratory, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD, USA., Biostatistics and Epidemiology, Clinical Center, National Institutes of Health, Bethesda, MD, USA., Urologic Oncology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA., Laboratory of Pathology, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA., Urologic Oncology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA. ., Radiology and Imaging Sciences, Clinical Center, National Institutes of Health, Bethesda, MD, USA. .