Safety margin of embolized area can reduce local recurrence of hepatocellular carcinoma after superselective transarterial chemoembolization

Background/Aims: We aimed to determine the relationship between the safety margin of an embolized area and local tumor recurrence (LTR) of patients with hepatocellular carcinoma (HCC) who underwent superselective transarterial chemoembolization (TACE). Methods: The medical records of 77 HCC patients with 109 HCC nodules who underwent superselective TACE were retrospectively analyzed for LTR. Univariate and multivariate analyses were performed for 16 potential factors using Cox proportional hazard regression. Iodized oil deposition on cone-beam computed tomography (CBCT) imaging was divided into three grades: A=complete tumor staining and complete circumferential safety margin, B=complete tumor staining but incomplete safety margin, C=incomplete tumor staining. The effect of a safety margin on LTR was evaluated by comparison between grade A and B group. Results: Univariate and multivariate analyses revealed that grade A iodized oil deposition and portal vein visualization were the only two independent significant factors of LTR (P< 0.001 and P=0.029, respectively). The 12-and 24-month LTR rates of tumors for grade A (n=62), grade B (n=30), and grade C (n=17) were 16% vs. 41% vs. 100% and 16% vs. 61% vs. 100%, respectively (P<0.001). The tumors in the grade A group had a 75% risk reduction in LTR (odds ratio, 0.25; 95% confidence interval, 0.10 to 0.64; P=0.004) compared to the grade B group. Conclusions: LTR was significantly lower when a greater degree of iodized oil deposition occurred with a complete circumferential safety margin. In superselective TACE, the safety margin of the embolized areas using intraprocedural CBCT affected LTR in HCC patients.