Overview and Current Status Of Contrast-Enhanced Imaging in Assessing Diagnosis Of HCC after TACE

Abstract

Hepatocellular carcinoma (HCC) is the fifth most common cancer and a principal cause of cancer-related deaths approximately one-third of cancer-related deaths worldwide. HCC appears on the background of a cirrhotic liver. The treatment strategies have been considerable developed during the last 30 years; the stage of HCC and the underlying liver function determine the therapeutic option and management of diseases. Transarterial chemoembolization (TACE) is considered the best treatment option of HCC nodules not suitable for curative treatment including surgery and liver transplantation. Moreover, the modified Response Evaluation Criteria in Solid Tumors (mRECIST) is vital to determine the degree of tumor necrosis. If there is a tumor with partial necrosis, retreatment or additional treatment including ethanol injection, radiofrequency ablation, and microwave or HIFU ablation may be performed to achieve complete necrosis after TACE. Different Imaging modalities used to evaluate the treatment response to TACE include contrast-enhanced computed tomography (CECT), contrast-enhanced ultrasound (CEUS), and contrast-enhanced magnetic resonance imaging (CEMRI). CECT has been commonly used as the standard imaging modality to evaluate the treatment response of HCC after TACE. However, several studies have reported a weak diagnostic performance of CECT for the assessing diagnosis of residual tumors after cTACE. In DEB-TACE, the half-life of doxorubicin is normally a long time that is why a very assessment of treatment response after treatment could be appropriate and the degree of tumor necrosis could be underestimated. The purpose of this current study was to perform a systematic review of the literature to present the ability of contrast-enhanced imaging to evaluate treatment response of HCC after TACE. The current available contrast-enhanced imaging modalities (CEUS, CECT, and CEMRI) and new CEUS techniques will be discussed to their advantages based on currently available literature and our experience in contrast-enhanced imaging. Of all available imaging modalities including CECT and CEMRI, CEUS is a valuable imaging modality to assess the treatment response of HCC after TACE, especially the conventional TACE and may provide comparable sensitivity and other benefits to CECT. As the result of new techniques and software, contrast-enhanced imaging may have their advantages in assessing diagnosis of HCC treatment response. The perspectives of contrast-enhanced imaging in clinical practice are promising and the development of new contrast agents, as well as new software for analyzing images, will gradually evolve. This will create new prospects for characterizing hepatic lesions and assessing the treatment response of HCC after TACE.