Percutaneous Radiofrequency Ablation of Perivascular versus Nonperivascular Hepatocellular Carcinomas ≤3 cm: Local Tumor Progression and Survival in an Inverse Probability of Treatment Weighting Analysis.

PURPOSE: To determine whether perivascular hepatocellular carcinoma (HCC) is associated with higher local tumor progression (LTP) and lower overall survival (OS) after percutaneous radiofrequency ablation (RFA) than nonperivascular HCC.

MATERIALS AND

METHODS

This retrospective study included consecutive 650 treatment-naive patients with a single small (≤3 cm) HCC treated with RFA between January 2005 and December 2020. Tumors were categorized as perivascular if the index lesion directly contacted a first- or second-order branch of the portal or hepatic vein ≥3 mm in diameter; otherwise, they were considered nonperivascular. Inverse probability of treatment weighting (IPTW) was applied using a propensity model that included age, sex, etiology of chronic liver disease, presence of cirrhosis, presence of portal hypertension, serum alpha-fetoprotein level, tumor size, and tumor location to balance baseline confounders between groups. LTP and OS were assessed using IPTW-adjusted Cox proportional hazards models.

RESULTS

The 5-year LTP rate was significantly higher in the perivascular group (28.6%) than in the nonperivascular group (12.9%) (P < .001). The 15-year OS rate was lower in the perivascular group (35.0%) than in the nonperivascular group (51.8%) (P = .011). Major adverse events occurred infrequently and were not significantly different between the groups (1.6% vs 0.9%, P = .328).

CONCLUSIONS

Perivascular tumor location was associated with higher recurrence and lower survival after RFA for small HCCs. In practice, identifying perivascular location should prompt careful treatment planning and consideration of adjunctive or alternative strategies.