Kidney Week

Abstract: SA-PO213

Comparing Glomerular Filtration Rate Equations with ⁵¹Cr-EDTA in Patients with Renal Tumors

Session Information

• Onco-Nephrology: Clinical
  November 09, 2019 | Location: Exhibit Hall, Walter E. Washington Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Onco-Nephrology

• 1500 Onco-Nephrology

Authors

• Rodrigues, Gilberto José, ICESP - USP (Sao Paulo State Cancer Institute, University of Sao Paulo), São Paulo, Brazil

Gilberto José Rodrigues,

• Guglielmetti, Giuliano Betoni, São Paulo State Cancer Institute, São Paulo, Brazil

Giuliano Betoni Guglielmetti,

• Torres, Veronica, Sao Paulo State Cancer Institute - USP, Sao Paulo, Brazil

Veronica Torres,

• Costalonga, Elerson, School of Medicine, University of Sao Paulo, São Paulo, SÃO PAULO, Brazil

Elerson Costalonga,

• Cordeiro, Maurício, São Paulo Institute Cancer Center, São Paulo, Brazil

Maurício Cordeiro,

• Caires, Renato Antunes, University of Sao Paulo School of Medicine, Sao Paulo, Brazil

Renato Antunes Caires,

• Nahas, William C., University of São Paulo Brazil, Sao Paulo, Brazil

William C. Nahas,

Background

Assessment of glomerular filtration rate (GFR) is a crucial element to plan surgical strategies in patients with renal tumors. However, the estimate GFR (eGFR) trough equations was not validated in these patients. The aim of this study is to compare the performance of Chronic Kidney Disease Epidemiology Collaboration Equation (CKD-EPI), abbreviated Modification of Diet in Renal Disease (aMDRD) and Cockcroft-Gault (CG) equations with 51Cr-EDTA in patients with renal tumors eligible to surgical treatment.

Methods

Prospective evaluation of 142 outpatients with renal tumors and submitted to partial nephrectomy at Sao Paulo State Cancer Institute between April 2013 and November 2018. All patients were evaluated before surgery with ⁵¹Cr-EDTA (rGFR) and serum creatinine (SCr), standardized to the isotope-dilution mass spectrometry reference method. rGFR and eGFR were expressed as ml/min/1.73 m².

Results

Patients were 59.4 ± 10.6 y, 50.2% male, 97.9% white. Renal tumor has 3.50 (2.70-4.72) cm at largest diameter and was malignant (histology confirmed post surgery) in 85% of cases. Comparing renal function before surgery, SCr was 0.86 (0.74 – 1.10) mg/d, rGFR was 81.1 ± 22.5 and rGFR < 60 was observed in 18% of pts. eGFRs using the CKD-EPI, aMDRD and CG equations were 80.6 ± 20, 77.3 ± 20.8, and 89.2 ± 30.6, respectively. CG and aMDRD showed significant differences in the means from the paired t-Test when compared to rGFR (P<0.05) (Figure 1 - Table 1). CKD-EPI equation demonstrated satisfactory precision and higher accuracy (Figure 1 - Table 2).

Conclusion

CG and aMDRD equations performed poorly compared with rGFR in this group of patients with renal tumors. CKD-EPI equation demonstrated adequate performance and should be considered when deciding upon surgical strategies in the setting of renal tumors.