Evaluation of algorithms for predicting new baseline renal function after complex partial nephrectomy for multifocal...

Area of Science:

• Nephrology
• Oncology
• Surgical Outcomes

Background:

• Partial nephrectomy (PN) preserves renal function for localized renal cancer.
• Existing models for predicting new-baseline-glomerular filtration rate (NBGFR) after PN were developed for single-tumor cases.
• Accurate NBGFR prediction is crucial for multifocal renal tumors, where repeat PNs may be necessary.

Purpose of the Study:

• To evaluate the performance of existing NBGFR predictive models in patients with multifocal renal tumors.
• To determine the most accurate method for predicting NBGFR in this specific patient population.

Main Methods:

• Retrospective analysis of 453 patients undergoing PN for ≥2 renal tumors (2006-2024).
• Included patients with available pre- and post-operative glomerular filtration rate (GFR) measurements.
• Assessed four predictive models using correlation coefficient (r) and mean-squared error (MSE).

Main Results:

• The cohort comprised 30% sporadic and 70% hereditary multifocal renal tumors.
• A simple formula, assuming 90% renal parenchymal preservation, demonstrated superior accuracy, bias, and precision (higher r, lower MSE) compared to multivariable models.
• GFR preservation per PN ranged from 85% to 91% and remained stable across sequential procedures.

Conclusions:

• Predictive models for NBGFR after PN performed well in multifocal renal tumor cases.
• The 90% parenchymal preservation formula most accurately predicted NBGFR.
• Renal parenchyma preservation is a key factor in determining NBGFR after PN for multifocal tumors.