Percutaneous cryoablation for high-complexity renal masses: complications, functional and oncological outcomes.

Background: During the past two decades cryoablation (CA) has become a therapeutic option for the management of localized cT1 renal masses in comorbid patients. We analyzed the mid-term functional and oncological outcomes of CA in the treatment of cT1 renal masses which were classified as high-complexity masses according to the PADUA system.
Methods: A total of 299 patients underwent percutaneous CA between November 2007 and December 2018 in 4 institutions for cT1N0M0 renal masses. All patients with high-complexity (PADUA≥10) renal tumors were included. Technical failure of CA was considered an exclusion criterion.
Results: Inclusion criteria were met by 45 patients. Median Charlson Comorbidity Index (CCI) was 6.0 (IQR: 5.0-7.0), median age was 74 years (IQR: 64.5-79.5). Seven Clavien 1 and 1 Clavien 2 procedure-related complications were reported. Median eGFR at baseline was 64.3mL/min (IQR: 52.0-82.3) while at the 1-year follow-up was 61.4 mL/min (IQR: 44.0-74.5). The median follow-up was 32 months (IQR: 13.25-47.5). Local recurrences were detected in 6 patients; 3 of them underwent re-cryoablation while the others started active surveillance. Median time to recurrence was 17.5 months (IQR: 7.8-27.3). Cancer-specific survival and metastasis-free survival were 100%, while overall survival was 86.7%.
Conclusions: CA proved to be a valuable therapeutic option for the management of patients with cT1 high-complexity PADUA≥10 renal tumors as it provides a low rate of procedural morbidity and good preservation of renal function. However, these results are counterbalanced by a recurrence rate that appears to be higher than those reported on surgically treated patients.