Small Renal Mass Cryoablation: Trifecta Outcomes of a Single-Institution Experience with a 20-Year Follow-Up

Cryoablation is a minimally invasive treatment option for patients with a small renal mass (SRM). We aimed to present the long-term functional and oncologic outcomes of cryoablation for SRMs.

We retrospectively reviewed patients treated with percutaneous or laparoscopic cryoablation for an SRM (≤4 cm in diameter) at our tertiary hospital between October 2001 and December 2011. Primary outcomes included technical failure (persistent CT enhancement post-ablation) and progression (local recurrence or metastasis). Trifecta is defined as the absence of severe complications (Clavien-Dindo > 2), no oncological progression, and ≤10% decline in eGFR.

A total of 129 patients with a median age of 67 (IQR 58-74) years were analyzed. The median (IQR) clinical and radiologic follow-ups across all patients were 136 (54-180) and 74 (23-147) months, respectively, with a median (IQR) tumor volume of 3.3 (1.6-6.6) cm³. Among those with available biopsy data (n = 86), 62 (72%) were diagnosed with Renal Cell Carcinoma (RCC), and 24 (28%) exhibited benign pathologies, including angiomyolipoma, oncocytic neoplasm, and non-diagnostic pathology. Of all patients, six experienced high-grade complications. Among non-solitary kidney patients with available creatinine values between 13 and 36 months post-treatment, 64% had ≤10% eGFR decline compared to baseline. Notably, 58% (26/48) of patients with RCC (non-solitary kidney) achieved our trifecta definition at 36 months. Metastasis-free, cancer-specific, and overall survival at 15-year follow-up were 85%, 96%, and 46%, respectively. Univariable regression identified tumor volume and solitary kidney status at ablation as significant predictors for oncological progression.

Cryoablation for the SRM showed sustained oncological and functional efficacy over long-term follow-up.