Measured GFR Using Renal Scan Improves Preoperative Clinical Decision in Patients with Kidney Cancer Who Are Surgical Candidates

Background: Measured GFR (mGFR) using Renal scan before renal surgery represents a precise tool able to better define the “real” renal status of oncological patients candidate to partial or radical nephrectomy. Moreover, Renal scan can also show the split renal contribution of kidneys. Nevertheless, its use in the preoperative workflow is controversial. Thus, we aimed at evaluating the role of renal scan in patients undergoing renal surgery comparing the mGFR with the most used eGFR formulas. Methods: We prospectively performed renal scan in 94 patients undergoing kidney surgery for cT1-2 renal mass between 2019 and 2022. Renal scan GFR measurement was compared with the most used eGFR formulas (MDRD, CKD-EPI 2021, JANOWITZ). CKD stages were defined according to the KDIGO 2023 classification. Sankey diagram was used to depict concordance between the different GFR estimates. Results: Descriptive analysis is shown in table 1. The agreement between eGFR formulas and measured GFR using renal scan is represented in table 2. Using the mGFR via renal scan, the baseline pre-operative reclassification of patients was greater than 35% with each type of eGFR formulas. (Figure 1). Conclusion: If renal scan is routinely used before kidney surgery, patient reclassification is observed in a non-negligible proportion of patients. Moreover, renal scan can identify patients with different split renal function, which does represent a key information for surgical planning and nephrological counseling .