Radiofrequency Ablation Covering the Entire Tumor Blood Drainage Area Improves Survival in Hepatocellular Carcinoma

Hepatocellular carcinoma has been considered to disseminate through the tumor blood drainage area. To improve curation rates, treatment should cover this area as it may contain satellite lesions. This retrospective study aimed to investigate whether radiofrequency ablation (RFA) completely covering the blood drainage area can improve the overall and disease‐free survival. We enrolled 526 patients who underwent computed tomography during hepatic arteriography following RFA from April 2001 to May 2019. Patients were categorized into a covered group in which the blood drainage area was completely covered by RFA and a noncovered group in which coverage was incomplete. The primary endpoint was the overall survival rate; secondary outcomes included disease‐free survival rate, distant intrahepatic and local recurrence rate, and changes in the Child‐Pugh score. There were no significant differences in baseline characteristics between the two groups. Cumulative overall survival rates were significantly higher in the covered group than in the noncovered group (hazard ratio, 0.63; 95% confidence interval, 0.48‐0.84; P = 0.002). On multivariate Cox proportional hazard model analysis, age