Percutaneous Cryoablation of Large Tumors: Safety, Feasibility, and Technical Considerations.

INTRODUCTION Large tumors may prove unsuitable for surgical cure or other local therapies due to their size, involvement of critical structures, prior non-ablative treatment failure, or coexisting disease burden. This study was performed to assess the safety and feasibility of percutaneous cryoablation for treatment of large tumors exceeding 6 cm in size, and to highlight the key technical considerations inherent to such cases. MATERIALS AND METHODS This single-institution retrospective study identified 77 patients (42 male, 35 female; median age 55 years) who underwent 96 cryoablation procedures for treatment of 78 tumors (mean diameter 9.8 ± 3.6 cm) from 2008 through 2020. Technical success, procedure-related complications, mortality, oncologic outcomes, and procedural logistics were evaluated. Technical success was defined as ice ball extension at least 5 mm beyond the tumor margins. RESULTS Intentional subtotal ablations were performed in 32% of cases due to tumor encroachment on vulnerable structures or as part of staged/combined therapies. Of the 68% of cases that were planned for complete ablation, the technical success rate was 100%. Major complications occurred after 19/96 (20%) procedures, with hemorrhage and acute kidney injury each occurring in 6/96 (6%). Post-procedural myositis occurred in 24/96 (25%) cases and was not considered a major complication in the absence of acute kidney injury. Local recurrence occurred in 2/23 (8.7%) of patients undergoing ablation for cure or local control at a median follow-up duration of 13 months. CONCLUSION Percutaneous cryoablation may be used to treat large (> 6 cm) tumors with a high degree of technical success and an acceptable safety profile.