Rapid Intrasegmental Progression After Percutaneous Radiofrequency Ablation for Hepatocellular Carcinoma: Incidence, Imaging Features, and Clinical Outcomes.

AIM: Radiofrequency ablation (RFA) is curative therapy for early-stage hepatocellular carcinoma (HCC), but a rare subset of patients develop aggressive intrasegmental recurrence shortly after complete ablation. We characterized the incidence, risk factors, and absolute risk. METHODS: This single-center retrospective study included consecutive patients with HCC treated with RFA from August 2002 to December 2024. Rapid progression was defined as recurrence at the ablation margin within 6 months that precluded further locoregional therapy. Cases were matched 1 to 4 with controls based on treatment era, prior RFA sessions, tumor diameter, and tumor number. Preablation imaging and tumor marker dynamics were compared, and absolute risk was estimated. RESULTS: Among 3163 patients who underwent 10,240 RFA treatments, 20 (0.20%) met criteria for rapid progression. Aggressive imaging features including nonsmooth margins (OR 5.87, 95% CI 1.80-19.12) and multinodular confluent growth (OR 3.84, 95% CI 1.30-11.36) were significantly more common in the rapid progression group, though positive predictive values remained below 1%. Irregular rim-like hyperenhancement was present in 15% of rapid progression cases but was absent in all controls. Periportal location accounted for half of the rapid progression cases (OR 2.84, 95% CI 0.97-8.29). Tumor markers including alpha-fetoprotein and des-gamma-carboxy prothrombin declined after RFA in controls but not in the rapid progression group. CONCLUSIONS: Aggressive imaging features and insufficient post-ablation tumor marker decline were associated with rapid progression, though individual predictive value was low. Tumor marker trends may help guide surveillance and earlier transition to systemic therapy.