Assessing the Correlation Between ⁶⁸Ga-PSMA-11 Renal PET Parameters and Renal Function Tests

⁶⁸Ga-prostate-specific membrane antigen (PSMA) ligands are used for prostate cancer but also show high renal cortical uptake. In this study, we aimed to assess whether there is any correlation between renal PSMA PET parameters and renal function tests using the images of prostate cancer patients. Methods: ⁶⁸Ga-PSMA-11 PET/CT images of the patients with prostate cancer were retrospectively evaluated. The following PET parameters were obtained: SUV_max, SUV_mean, SUV_max corrected for lean body weight, SUV_mean corrected for lean body weight, volume, lean body weight--corrected total lesion glycolysis (TLG_SUL), and counts of both kidneys, as well as SUV_mean of the liver, blood pool, and spleen. Total TLG_SUL, total volume, kidney-to-liver ratio, and kidney-to-blood pool ratio were calculated. Creatinine values were obtained, and glomerular filtration rate (GFR) was calculated using the "Modification of Diet in Renal Disease" formula. Statistical analysis was performed to understand whether there is a correlation between the above parameters and renal function tests. Results: Twenty-five patients were included in this study. GFR was significantly and positively correlated and creatinine was significantly and negatively correlated with the ratios of renal SUV to liver SUV and renal SUV to blood pool SUV. GFR was marginally positively correlated with renal SUV_mean corrected for lean body weight, and creatinine was marginally negatively correlated with total TLG_SUL Total renal parenchymal volume was significantly and directly (positively) associated with GFR and significantly and inversely (negatively) associated with creatinine. Conclusion: Renal ⁶⁸Ga-PSMA uptake appears to be correlated with renal function tests. Our method of measuring approximate renal parenchymal volume on PET images appears to be reliable.