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Kidney Week

Abstract: SA-PO906

Iohexol Renal Measurement In Uro-Oncological Patients: Ready to Quit Pandora's Box?

Session Information

Category: CKD (Non-Dialysis)

  • 2102 CKD (Non-Dialysis): Clinical, Outcomes, and Trials

Authors

  • Trevisani, Francesco, IRCCS San Raffaele Scientific Institute, Milan, Italy
  • Di marco, Federico, IRCCS San Raffaele Scientific Institute, Milan, Italy
  • Locatelli, Massimo, IRCCS San Raffaele Scientific Institute, Milan, Italy
  • Pizzagalli, Giorgio, IRCCS San Raffaele Scientific Institute, Milan, Italy
  • Larcher, Alessandro, IRCCS San Raffaele Scientific Institute, Milan, Italy
  • Capitanio, Umberto, IRCCS San Raffaele Scientific Institute, Milan, Italy
  • Bettiga, Arianna, IRCCS San Raffaele Scientific Institute, Milan, Italy
  • Cinque, Alessandra, IRCCS San Raffaele Scientific Institute, Milan, Italy
  • Porrini, Esteban, University Hospital of the Canary Island, La Laguna, Spain
  • Briganti, Alberto, IRCCS San Raffaele Scientific Institute, Milan, Italy
  • Salonia, Andrea, IRCCS San Raffaele Scientific Institute, Milan, Italy
  • Montorsi, Francesco, IRCCS San Raffaele Scientific Institute, Milan, Italy
Background

An accurate assessment of renal function in urological and oncological patients should be mandatory to define the most appropriate urological surgery technique (nephron sparing vs radical nephrectomy) and to decide the correct dose for each type of chemo-immuno therapy. Unfortunately, the most used method to measure GFR in clinical practice is represented by the estimated glomerular filtration rate (eGFR) which harbours error in comparison to gold standards methods (mGFR). The objective of this study is to determine the extent of the error of eGFR in the oncological and urological pts category.

Methods

A prospectively consecutive cohort of 91 pts affected by uro-oncological neoplasm was collected comparing eGFR with mGFR using iohexol renal measurement. Four estimated GFR formulas were used for this study: CKD-EPI, MDRD, MCQ, FAS. The agreement them was evaluated taking in account Bias, expressed as median of percent difference between mGFR and eGFR and overall accuracy as P30 representing the percent of estimates within 30% of measured GFR.

Results

The agreement between formulas and mGFR was poor. The Bias for MDRD was -1%, for CKD-EPI was 0%, for FAS was 1% and for MCQ was -19% indicating that, except for the latter, those formulas don’t harbour systematic errors. Different information was provided by the accuracy parameter: the P30 was 81% for CKD-EPI, 76% for MDRD, 82% for FAS and 58% for MCQ.

Conclusion

In our cohort study we observed that formulas equally over or underestimate mGFR resulting in unbiased methods; however the magnitude of the over/underestimations is not negligible, at least ± 20 mL/min/1.73 m2, and could led to errors in clinical management.

eGFR formulas vs mGFR: Black line represents identity; red dotted lines represent P30 boudaries