Percutaneous Ablation vs Robot-Assisted Partial Nephrectomy for Completely Endophytic Renal Masses: A Multicenter Trifecta Analysis with a Minimum 3-Year Follow-Up

Abstract

Purpose: To compare outcomes of robot-assisted partial nephrectomy (RAPN) and percutaneous tumor ablation (PTA) for completely endophytic renal masses. Methods: Data of patients who underwent RAPN or PTA for treatment of completely endophytic (three points for "E" domain of R.E.N.A.L. score) were collected from seven high-volume U.S. and European centers. PTA included cryoablation, radiofrequency, or microwave ablation. Baseline characteristics, clinical, surgical, and postoperative outcomes were compared. Recurrence-free survival (RFS) was calculated with Kaplan-Meier analysis. Trifecta was used as arbitrary combined outcome parameter as proxy for treatment "quality." Multivariable logistic regression model assessed predictors of trifecta failure. Results: One hundred fifty-two patients (RAPN, n = 60; PTA, n = 92) were included in the analysis. RAPN group was younger (p < 0.001), had lower American Society of Anesthesiologists score (p = 0.002), and higher baseline estimated glomerular filtration rate (p < 0.001). There was no difference in clinical tumor size, clinical T stage, and tumor complexity scores. PTA had significantly lower rate of overall (p < 0.001) and minor (p < 0.001) complications. ΔeGFR at 1 year was statistically higher for RAPN (-15.5 mL/min vs -3.1 mL/min; p = 0.005), no difference in ΔeGFR at last follow-up (p = 0.22) was observed. No difference in recurrences (RAPN, n = 2; PTA, n = 6) and RFS was found (p = 0.154). Trifecta achievement was higher for RAPN but not statistically different (65.3% vs 58.8%; p = 0.477). R.E.N.A.L. Nephrometry Score resulted predictive of trifecta failure (odds ratio = 1.47; confidence interval = 1.13-1.90; p = 0.004). Conclusions: PTA confirms to be an effective treatment for completely endophytic renal masses, offering low complications and good mid-term functional and oncologic outcomes. These outcomes compare favorably with those of RAPN, which seem to be the preferred option for younger and less comorbid patients.

Keywords: endophytic renal mass; kidney cancer; percutaneous tumor ablation; robot-assisted partial nephrectomy; small renal tumor.