Imaging features of microvascular invasion in hepatocellular carcinoma developed after direct-acting antiviral therapy in HCV-related cirrhosis.

OBJECTIVES: To evaluate imaging features of microvascular invasion (MVI) in hepatocellular carcinoma (HCC) developed after direct-acting antiviral (DAA) therapy in HCV-related cirrhosis. METHODS: Retrospective cohort study on 344 consecutive patients with HCV-related cirrhosis treated with DAA and followed for 48-74 weeks. Using established imaging criteria for MVI, HCC features were analysed and compared with those in nodules not occurring after DAA. RESULTS: After DAA, HCC developed in 29 patients (single nodule, 18 and multinodular, 11). Median interval between therapy end and HCC diagnosis was 82 days (0-318). Forty-one HCC nodules were detected (14 de novo, 27 recurrent): maximum diameter was 10-20 mm in 27, 20-50 mm in 13, and > 50 mm in 1. Imaging features of MVI were present in 29/41 nodules (70.7%, CI: 54-84), even in 17/29 nodules with 10-20 mm diameter (58.6%, CI: 39-76). MVI was present in only 17/51 HCC nodules that occurred before DAA treatment (33.3%, CI: 22-47) (p= 0.0007). MVI did not correlate with history of previous HCC. CONCLUSIONS: HCC occurs rapidly after DAA therapy, and aggressive features of MVI characterise most neoplastic nodules. Close imaging evaluations are needed after DAA in cirrhotic patients. KEY POINTS: • In HCV cirrhosis, hepatocellular carcinoma develops soon after direct-acting antiviral therapy. • HCC presents imaging features of microvascular invasion, predictive of more aggressive progression. • Cirrhotic patients need aggressive and close monitoring after direct-acting antiviral therapy.