Objective: To investigate technical factors affecting local tumor control of small hepatocellular carcinoma (HCC) treated by superselective conventional transarterial chemoembolization (cTACE) using lipiodol and to compare prognoses between groups with and without these factors.
Materials and methods: Sixty-three consecutive patients with 73 HCC nodules (diameter, 1-3 cm) treated by cTACE were retrospectively analyzed. A positive or a negative 3D-safety margin was defined as a ≥ 1-mm area of lipiodol accumulation or as a diameter of lipiodol accumulation < 1 mm in liver parenchyma surrounding the tumor using plain CT images obtained within a week after TACE. Uni- and multivariate analyses were performed to identify technical factors determining local tumor control rate. Subgroup analysis of survival rates in treatment-naïve patients was performed according to the detected factors.
Results: In univariate analyses, three-dimensional (3D)-safety margin and portal vein visualization were associated with local tumor control rates. In multivariate analysis, only positive 3D-safety margin remained a significant contributor (p = 0.001). Two-year cumulative local disease-free survival rates with positive and negative 3D-safety margin were 82.8% and 19.3%, respectively (p = 0.001). In subgroup survival analysis of the 36 newly diagnosed patients, the 1-, 2-, 3-, 4-, and 5-year cumulative OS rates for patients with and without positive margins were 100% versus 100%, 96.4% versus 75.0%, 81.8% versus 62.5%, 74.4% versus 41.7%, and 47.0% versus 0%, respectively (median survival time; 57.6 months vs. 37.1, p = 0.047).
Conclusion: Obtaining a 3D-safety margin can suppress local tumor recurrence and prolong survival in superselective cTACE for small HCC.
Keywords: Ethiodized oil; Hepatocellular carcinoma; Prognosis; Recurrence; Three-dimensional safety margin; Transarterial chemoembolization.