R.E.N.A.L. (Radius, Exophytic/Endophytic, Nearness to Collecting System or Sinus, Anterior/Posterior, and Location Relative to Polar Lines) nephrometry score predicts early tumor recurrence and complications after percutaneous ablative therapies for renal cell carcinoma: A 5-year experience

Purpose To investigate the prognostic value of R.E.N.A.L. (radius, exophytic/endophytic, nearness to collecting system or sinus, anterior/posterior, and location relative to polar lines) nephrometry score after percutaneous ablation of renal cell carcinoma (RCC). Materials and Methods A retrospective 5-year study was performed. Participants were 87 consecutive patients (median age, 67.1 y; 59.7% male, 40.3% female) with 101 biopsy-proven RCCs who underwent percutaneous ablation (54.0% cryoablation, 46.0% radiofrequency ablation). Follow-up computed tomography or magnetic resonance imaging was performed in all cases (mean follow-up, 34.6 mo ± 23.5). R.E.N.A.L. scores were analyzed to determine the association of the score with treatment outcomes and complications. Results All tumors corresponded to stage 1A disease. Mean tumor size was 2.05 cm (range, 0.7-3.9 cm), and 50.5% of the lesions measured > 2 cm. Nephrometry score was > 8 in 31.4% of lesions. Overall recurrence rate was 16.8%, first-year recurrence rate was 7.9%, and complication rate was 9.9%. A nephrometry score > 8 was associated with increased complications after percutaneous ablation (P <.0001), increased overall recurrence (P <.0001), and increased risk of first-year recurrence (P <.0001). Immediate complications were associated with tumor size > 2 cm (P <.0001) and risk of local recurrence (P <.001). Age, gender, and percutaneous ablation technique were not correlated with recurrence or immediate complications. Patients undergoing cryoablation had a higher nephrometry score with no significant differences in recurrence rate compared with RF ablation (P =.199). Conclusions A R.E.N.A.L. nephrometry score ≥ 8 predicts recurrence and complications after percutaneous renal ablation.