39 - Predictive Performance of Renal Complexity Scoring Systems for Adverse Events and Recurrence Following Cryoablation of Renal Masses

Sunday, April 12, 2026

4:12 PM - 4:21 PM ET

Presenting Author(s)

VZ

Vagif Zeynalli, MS

Medical Student
Schulich School of Medicine & Dentistry, Canada

Author/Co-author(s)

Fu (Jorden) Lo, MD, BSc

PGY2 in Diagnostic Radiology
London Health Sciences Centre, Canada
AM

Amol Mujoomdar, MD FSIR

Professor of Interventional Radiology, Oncology and Medical Biophysics
Western University, Canada
RK

Roman Kozak, MD

Associate Professor
Department of Medical Imaging, Western University, Canada
LC

Leandro Cardarelli Leite, MD

Interventional Radiologist
University of Western Ontario, Canada
DH

David Hocking, MD

Assistant Professor
Dept of Medical Imaging, Western University, London, Ontario, Canada, Canada
SP

Stephen Pautler, MD

Professor
Division of Urology, Dept of Surgery, Western University, London, Ontario, Canada, Canada
DC

Derek W. Cool, MD, PhD

Radiologist - Assistant Professor
Department of Medical Imaging, Western University, London ON, Canada, Canada

Purpose: To evaluate the predictive performance of five renal complexity scoring systems (RENAL, mRENAL, PADUA, (MC)², and P-RAC) in predicting adverse events and recurrence following cryoablation of renal masses.

Materials and Methods: A retrospective single-center study identified 137 patients with 139 renal masses treated with cryoablation between April 2007 and June 30, 2022. Patients had a mean age of 69.8 ± 9.02 years (range: 47–86) (M:F 96:41, BMI 30.9 ± 8.5, Charlson Comorbidity Index 6.1 ± 1.9) with a median follow-up of 5.1 years (range: 0.6–17.3). The mean tumor size was 3.4 ± 1.1 cm (T1a: 106, T1b: 32, T2: 1). Pathology was known in 113 tumors (81.3%): 107 RCC (94.7%), 5 oncocytoma (4.4%), and 1 lymphoma (0.9%). Among RCC, 65.4% were clear cell, 23.4% papillary, 3.7% chromophobe, 2.8% clear cell papillary, 0.9% tubulocystic, and 3.7% not specified. Mean complexity scores were: RENAL 7.1 ± 1.7, mRENAL 7.6 ± 1.9, PADUA 8.0 ± 1.5, MC² 5.2 ± 2.2, and P-RAC 8.4 ± 2.5. Outcomes assessed included adverse events and disease recurrence. Predictive performance was analyzed using ROC curves and generalized estimating equation (GEE) logistic regression to account for multiple tumors per patient.

Results: Adverse events occurred in 15.1% of ablations. None of the complexity scores significantly predicted adverse events. MC² had the highest discrimination (AUC 0.61, 95% CI 0.47–0.76) with a trend toward association on regression (OR 1.19 per point, p=0.086). RENAL (AUC 0.56), mRENAL (0.57), P-RAC (0.55), and PADUA (0.51) showed poor predictive value. For recurrence, 16 of 127 (12.6%) patients with complete ablation experienced disease recurrence. MC² achieved the highest predictive performance (AUC 0.69, 95% CI 0.55–0.84) and was the only independent predictor on regression analysis (OR 1.37 per point, 95% CI 1.10–1.71, p=0.005). P-RAC (AUC 0.63, p=0.096), RENAL (0.60), and mRENAL (0.61) showed modest but non-significant associations. PADUA performed poorly (AUC 0.54, p=0.49).

Conclusion: All 5 renal complexity scores showed limited value for predicting adverse events after cryoablation. MC² demonstrated modest predictive value for disease recurrence and was the only independent predictor. These findings suggest MC² may provide incremental value in pre-procedural risk stratification for renal cryoablation, while other nephrometry systems show limited utility.