Assessment of the treatment response of HCC.

Surgical hepatectomy or liver transplantation are considered as curative treatment modalities for hepatocellular carcinoma (HCC). However, many patients are not surgical candidates at the time of diagnosis. Great improvements in locoregional therapies including local ablative therapy [radiofrequency (RF) ablation or ethanol ablation] and transarterial techniques (transarterial embolization or transarterial radioembolization) have made possible local control of HCC. For unresectable HCC, a targeted therapy with sorafenib may improve survival. Unlike treatment of other oncologic tumor, the locoregional therapies are mainstay in the treatment of HCC. Therefore, the application of classical criteria such as the World Health Organization (WHO) guideline may not be suitable for accurate treatment response assessment of locoregional therapies or targeted therapy of HCC. An understanding of the imaging features of post-treatment imaging after various treatment modalities for HCC is crucial for treatment response assessment and for determining further therapy. In this article, we review the role of various imaging modalities in assessing treatment response of locoregional therapies and the targeted molecular therapy.