Dynamic Contrast-enhanced Magnetic Resonance Imaging for Assessment of Response to Transarterial Chemoembolization of Hepatocellular Carcinoma

Background: Liver cancer is the second leading cause of cancer deaths worldwide. Hepatocellular carcinoma (HCC) typically presents arterial phase hyperenhancement. For intermediate stage disease and the majority of patients not eligible for curative therapies, transarterial chemoembolization (TACE) is considered as the first-line palliative treatment in eligible patients.

Despite its efficacy on HCC, TACE presents major challenges such as the lack of quantitative biomarkers of treatment response. Dynamic contrast-enhanced MRI (DCE-MRI) enables quantitative assessment of tumor and tissue enhancement, by acquiring MR signal intensity as a function of time.

Objectives: This study is conducted: 1) to develop a monitoring system based on quantifiable measures during intra-arterial treatments from dynamic MRI, using time-activity curves analyzed using a dual-input dual-compartment model, and 2) to look at blood flow curves of the MRI before the treatment, if any, for at least one tumor, without requiring any breath hold.

Design:

• Post-treatment phase group: This will be a prospective study in HCC patients undergoing TACE (including DC beads) according to their clinical standard of care. A 4D-THRIVE sequence will be performed. Single intensities before/after gadolinium-based contrast agent enhancement will be used to create time-concentration curves, which will be fitted to a simple perfusion model that accounts for the dual blood supply of the liver through the hepatic artery and the portal vein. Perfusion parameters of arterial hepatic blood flow, portal venous hepatic blood flow, total hepatic blood flow and arterial fraction will be extracted from the model and compared between HCC and surrounding cirrhotic liver. When deemed necessary, a CBCT can be acquired before chemo-embolization in way to see that the appropriate artery is selected for the treatment. The CBCT will be used when available to determine the parameters of the blood flow obtained with our model.
• Pre-treatment phase group: This will be a prospective study in HCC patients undergoing a MRI according to their clinical standard of care. A 4D-THRIVE sequence will be performed. Single intensities before/after gadolinium-based contrast agent enhancement will be used to create time-concentration curves, which will be fitted to a simple perfusion model that accounts for the dual blood supply of the liver through the hepatic artery and the portal vein. Perfusion parameters of arterial hepatic blood flow, portal venous hepatic blood flow, total hepatic blood flow and arterial fraction will be extracted from the model and compared between HCC and surrounding cirrhotic liver.
• Comparison: A comparison between the blood flow curves between the post-treatment phase group [apnea] and the pre-treatment phase group [free-breathing] will be done.