The Safety Standards for Liver Percutaneous Thermal Ablation: A Meta-Analysis of Adverse Events over 15 Years

Background Percutaneous thermal ablation (PTA), including radiofrequency and microwave ablation, has been established as a curative therapy for small malignant liver neoplasms; yet, as clinical indications expand, overall safety remains good, although the exact incidence of complications varies among studies. Purpose To determine updated benchmarks for procedure-related mortality and major adverse events (AEs) after PTA of malignant liver tumors. Materials and Methods In this systematic review and single-proportion meta-analysis of patients who underwent thermal ablation of malignant liver tumors, Cochrane, MEDLINE, and Embase were searched for prospective randomized or cohort studies published from January 2007 to September 2022 that reported AEs after radiofrequency or microwave ablation of three or fewer liver tumors measuring 5 cm or smaller, over at least 90 days of follow-up. Two reviewers independently screened the studies, extracted data, and assessed the risk of bias. Pooled proportions of significant AEs (ie, Society of Interventional Radiology grades C-E), including 90-day procedure-related mortality, were calculated with random-effects models. Results Forty-nine studies comprising 4149 patients and 4636 ablations met the inclusion criteria. The pooled proportion of significant AEs was 3.0% (86 of 3149 patients; 95% CI: 2.50, 3.67; I² = 0%). The 90-day procedure-related mortality rate was 0.01% (one of 4149 patients; 95% CI: 0.007, 0.014). The AE rates did not differ significantly between radiofrequency and microwave ablation (3.21% vs 2.65%; P = .41) or between hepatocellular carcinoma and metastatic tumors (2.94% vs 3.91%; P = .85). Conclusion PTA of malignant liver tumors is associated with near-zero 90-day mortality and a 3% major complication rate. © RSNA, 2026 Supplemental material is available for this article. See also the editorial by Bettmann in this issue.