Dynamic Contrast-enhanced Magnetic Resonance Imaging in Evaluation of Liver Functional Status and Treatment Efficacy in Patients With Hepatocellular Carcinoma After Locoregional Therapy

Hepatocellular carcinoma (HCC) is a major health problem worldwide. For patients with intermediate-stage disease, i.e., large or multifocal HCC without vascular invasion or extrahepatic spread, transarterial chemoembolization (TACE) is recommended as first line therapy with survival advantages. TACE can be performed repeatedly in patients with recurrent tumors who have adequate liver function reserves.

Two clinical issues of TACE remain un-resolved. The first issue is the possibility of TACE-induced liver parenchymal damage, which may influence further treatment options and outcome of the patients. Conventional ways to evaluate liver functional reserves, including Child-Pugh score, biochemistry and metabolic tests, and ultrasound elastography, are relatively non-specific. The second issue is the difficulty in evaluating TACE efficacy, which cannot be reliably measured by conventional, volumetric response criteria. Both issues should be resolved to optimize patient care.

Recently dynamic contrast-enhancing magnetic resonance imaging (DCE-MRI) is increasingly used to analysis perfusion changes of the liver, and can be applied to both liver parenchyma and tumors. Previous studies have shown clinical applications of perfusion imaging, such as evaluating the severity of liver fibrosis and cirrhosis, assessing the effectiveness of anti-angiogenic therapy, and evaluating tumor viability after locoregional therapy. DCE-MRI can be performed with a hepatobiliary specific contrast agent, Gd-EOB-DTPA (Gadoxetic acid, Primovist®, Bayer Schering), with dual benefit of dynamic phase and the delayed hepatobiliary phase imaging. The hepatobiliary phase imaging can provide additional information for hepatic lesion characterization and the functional status of the hepatocytes. We hypothesize that imaging parameters of DCE-MRI with Gd-EOB-DTPA could reflect non-tumorous liver parenchymal changes and can be used to predict and monitor treatment response in patients with HCC after TACE.

In this prospective cohort study, we will recruit patients referred for TACE with newly-diagnosed unresectable HCC or tumor recurrence after operation. Patients treated with radiofrequency ablation (RFA) will be recruited as a control group, since RFA is associated with minimal damage to the non-tumorous liver parenchyma. Key eligible criteria include chronic hepatitis B, histological or clinical diagnosis of HCC, tumors that are not amenable to surgical treatment and referred for TACE or RFA, ECOG performance status 0 or 1, Child-Pugh class A or B liver function, and measurable tumors (by RECIST 1.1). Eligible patients will receive the designated treatment (TACE or RFA) according to the current HCC treatment guidelines. DCE-MRI with Gd-EOB-DTPA will be used to analyze the non-tumorous liver parenchymal changes and treatment response, and will be performed at baseline, 3 days and 1 month after treatment, and then every 3 months for a maximum of 2 years. The primary endpoint of this study is progression of liver function reserve. The estimated time for patient recruitment is about half a year, and 40 patients and 20 patients will be recruited in the TACE and the RFA treatment group, respectively. The imaging parameters of the non-tumorous parenchyma and the tumors will be analyzed and correlated with clinical liver function parameters, and hepatic functional and tumor outcome of the patients.