Percutaneous Cryotherapy and Radiofrequency Ablation of Renal Masses: Multicenter Comparative Analysis with Minimum 3-Year Follow-up.

Background: Different modalities of percutaneous thermal ablation (PTA) have been used as possible minimally invasive nephron-sparing treatments for small renal masses (SRMs). The present study aimed to compare long-term outcomes of two guidelines-recommended ablative techniques, cryotherapy (CRYO) and radiofrequency ablation (RFA).

Materials and methods: Data of patients with single cT1 solid renal mass undergoing CRYO or RFA between 2004 and 2020 were retrospectively retrieved from a multi-institutional international database. Oncologic outcomes included "technical success", local recurrence-free survival (RFS), distant metastasis-free survival (MFS), and overall survival (OS). Intraoperative and postoperative complications, length of stay (LOS), and re-admission rate within 30 days were registered. Major complications were defined as CD grade ≥III. Baseline features and treatment outcomes were analyzed using descriptive statistics. RFS, MFS, and OS were estimated using the Kaplan-Meier method.

Results: Overall, 643 patients were included, of which 492 (71.2%) underwent CRYO, and 151 (21.8%) RFA, with a median follow-up of 43 and 37 months, respectively (p=0.07). Technical success was achieved in 96.5% of CRYO vs 93.4% of RFA (p=0.09). No difference in terms of overall (CRYO: 10.4% vs RFA: 6%; p=0.1) and "major" (CRYO: 0.8% vs RFA: 1.3; p=0.06) post-operative complications were observed. RFS (CRYO:85.7%; RFA:84.9%, p=0.2), MFS (CRYO: 96.9%; RFA: 95.8%, p=0.4) and OS (CRYO: 89%; RFA: 87.4%; p=0.8) were comparable.

Conclusions: CRYO and RFA are both valid minimally invasive options for the treatment of small renal tumors. They are particularly suitable for patients who are not good surgical candidates as they offer very low risk of major procedure-related complications. For the right indication, they both offer favorable mid to long term oncologic outcomes.