Locoregional radiological treatment for hepatocellular carcinoma; Which, when and how?

Hepatocellular carcinoma (HCC) is one of the most frequent and deadliest cancers worldwide. Liver transplantation, surgical resection or local ablation offer the best survival advantages but most patients either present when the tumor is in an advanced stage or the degree of underlying liver disease precludes these options. Several therapies have been proposed for these patients with proven survival benefits. These therapies comprise the locoregional treatment for HCC, and include percutaneous ethanol injection (PEI), radiofrequency ablation (RFA), transarterial chemoembolization (TACE), transarterial radioembolization (TARE), and drug-eluting bead (DEB). PEI and RFA are considered curative treatments for early stage HCC; whereas TACE is a standard of care for intermediate stages. Additionally, evaluation of response to locoregional treatment in HCC is important, as objective response may become a surrogate marker for improved survival. Currently, there are several criteria for response assessment, including the World Health Organization (WHO), the Response Evaluation Criteria in Solid Tumors (RECIST), the European Association for the Study of the Liver Criteria (EASL), and the modified RECIST (mRECIST); however, there has been poor correlation between the clinical benefit provided by locoregional interventional therapies and conventional methods of response assessment. The aim of our study was to review and analyze the current evidence for radiological interventions in HCC, and to propose evidence based recommendations to improve the management of these patients.