Hepatocellular Carcinoma: CT for Tumor Response after Transarterial Chemoembolization in Patients Exceeding Milan Criteria-Selection Parameter for Liver Transplantation

Purpose: To retrospectively evaluate the clinical outcome of patients with hepatocellular carcinoma (HCC) who exceeded the Milan criteria, who underwent transarterial chemoembolization (TACE) before orthotopic liver transplantation (OLT), to determine the value of computed tomography (CT)-based tumor response to TACE as a preoperative selection criterion for OLT. Materials and Methods: The study included 33 patients with HCC who exceeded the Milan criteria and underwent OLT after TACE. Informed written consent was obtained before TACE and OLT. Institutional review board approval was not required. Tumor response to TACE was evaluated at 1 month with CT according to amended Response Evaluation Criteria in Solid Tumours (RECIST) guidelines. In the explanted liver, degree of tumor necrosis (>= 90%, 50%-89%, or, 50%), residual tumor stage and grade, and presence of microvascular invasion were assessed. Follow-up after OLT ranged from 1 to 143 months. Results: After TACE, CT showed complete tumor response (CR) in 18 (55%) patients. On the explanted liver, tumor necrosis was rated 90% or greater in 20 (61%) patients, with a good correlation with CT. Microvascular invasion was observed in nine (27%) of 33 patients; none of them were reported to have a CR at CT. The 5-year cumulative survival rate after OLT was 72.5%; it was significantly (P=.003) higher in patients with a CR (94.4%) compared with patients with a partial response (PR) (45.4%) and stable disease (50%). The 5-year cumulative recurrence-free rate after OLT was 74.4%; it was not affected by the tumor nodule size and number, whereas it was significantly (P=.008) higher in patients with a CR (94.4%) compared with patients with a PR (46.7%) and stable disease (50%). Conclusion: In patients with HCC who exceeded the Milan criteria, a CR after TACE, on the basis of amended RECIST guidelines, is associated with excellent posttransplantation outcomes. Therefore, 1-month response to TACE assessed at CT may represent a valid selection criterion for OLT. (C) RSNA, 2010