Purpose: We evaluated iodized oil accumulation in the hypovascular portion of early-stage hepatocellular carcinoma (HCC) after ultraselective transcatheter arterial embolization (TACE).
Materials and methods: Forty-seven HCC lesions with hypovascular portions were treated by TACE at the distal level of the sub-subsegmental artery of the liver. Portal blood in the hypovascular portion was classed in two grades by computed tomography (CT) during arterial portography: decreased and preserved. Iodized oil accumulation was classed into three grades on CT obtained 1 week after TACE: (1) dense accumulation in the almost entire tumor, including the hypovascular portion (grade 2); (2) dense accumulation in hypervascular portions but sparse accumulation in hypovascular portion (grade 1); and (3) sparse accumulation or no accumulation (grade 0). Findings on serial follow-up CT images were also analyzed.
Results: Portal blood in the hypovascular portion was decreased in 32 lesions, and preserved in 15 lesions. On CT 1 week after TACE, 32 tumors (68.1%)-23 with decreased portal blood and 9 with preserved portal blood-were classed as grade 2. Twelve tumors (25.5%), six with decreased portal blood and six with preserved portal blood, were classed as grade 1. Three tumors (6.4%) with decreased portal blood were classed into grade 0. In total, 25 tumors (53.2%), 22 in grade 2 and 3 in grade 1, were well controlled by ultraselective TACE during the mean follow-up of 15.8 months.
Conclusions: Iodized oil accumulation and retention in the hypovascular portion of early-stage HCC was frequently observed after ultraselective TACE, mainly in the hypovascular portion with decreased portal blood.