Imaging of treatment response during systemic therapy for hepatocellular carcinoma

Systemic therapy for the treatment of hepatocellular carcinoma (HCC) has rapidly evolved over the last 4 years; eight new drug regimens have gained Food and Drug Administration approval for treatment of advanced HCC since 2017. As several lines of therapy are now available for the treatment of HCC, accurate CT and MRI treatment response assessment is important for informing optimal management of affected patients. This article will review the systemic therapies currently approved for the treatment of HCC, focusing on items most pertinent to radiologists. Treatment response assessment of patients with HCC undergoing systemic therapy differs from treatment response assessment of patients receiving locoregional therapies, and principle differences will be highlighted. Finally, this review will provide a framework for the interpretation of CT and MRI examinations of patients with HCC being treated with systemic therapy and will explore the relevant scientific data currently available.