<b>Purpose</b><br/>Tumor location influences the effectiveness and safety of radiofrequency ablation (RFA). This study evaluated RFA outcomes as first-line therapy for hepatocellular carcinoma (HCC) <3 cm, focusing on tumor location impact.
<br/><b>Materials and Methods</b><br/>In this retrospective cohort study, 281 patients with newly diagnosed HCC <3 cm in up to three lesions treated with RFA between 2003 and 2019 were analyzed. The tumor location was categorized as superficial (outer third), mid-portion (middle third), or deep (near vena cava), using an imaginary line from the liver surface to the vena cava. Perivascular tumors were defined as those abutting portal or hepatic veins. Recurrence-free survival (RFS) among location groups was compared with risk factors analyzed via Cox regression.
<br/><b>Results</b><br/>Patients (mean age, 61.1 ± 11.1 years) were predominantly male (73.3%), hepatitis B virus surface antigen–positive (66.2%), and of Child-Pugh class A (97.5%). Deep tumors had shorter RFS than superficial/mid-portion tumors (hazard ratio [HR], 1.87; 95% confidence interval [CI], 1.20 to 2.93; p = 0.005), as did perivascular versus non-perivascular tumors (HR, 1.87; 95% CI, 1.16 to 3.00; p = 0.008). Group C (deep + perivascular, n = 10) had shorter RFS than group A (no risk factors: HR, 3.12; 95% CI, 1.50 to 6.45; p = 0.002) and group B (one risk factor: HR, 1.59; 95% CI, 1.05 to 2.40; p = 0.028). Multivariable analysis identified tumor depth, perivascular location, size >2 cm, creatinine, and prothrombin time as independent predictors of shorter RFS.
<br/><b>Conclusion</b><br/>Tumor depth and proximity to vasculature independently predict RFS in small HCCs treated with RFA, highlighting the role of tumor location in determining patient prognosis.