DCE-MRI for Assessment of Response to TACE of HCC

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.

Methods: Forty patients will be selected. For twenty-nine of them [post-treatment phase group], a 4D-THRIVE sequence will be acquired within 2 weeks prior to TACE and between 6 and 8 weeks after TACE. A 4D-FLOW MRI sequence will also be included. For the remaining eleven patients [pre-treatment phase group], only a 4D-THRIVE sequence will be acquired within 2 weeks prior to treatment, if any, including a 4D-FLOW MRI sequence.

Expected results: The results of this study will provide quantitative DCE-MRI biomarkers for identification of viable tumor and tumor response. In addition, presence of increased % arterial flow and decreased portal venous flow in HCC using DCE-MRI are expected to help to assess treatment response.

Inclusion criteria

• All patients:

• Are at least 18 years old at screening;
• Able to comprehend and willingness to provide voluntary consent;
• Have at least one HCC;
• HCC lesion of at least 10 mm;
• Understand French or English instruction.
• Post-treament phase group:

• Are able to have a MRI before and after TACE;
• Must undergo a TACE as part of their clinical standard of care for HCC;
• Have a new prescription for TACE for at least one HCC.
• Pre-treatment phase group:

• Are able to have a MRI before treatment (if any);
• Must undergo an MRI as part of their clinical standard of care for HCC.

Exclusion criteria

• Have any contra-indication for MRI (such as claustrophobia, pacemaker, metallic clips for a neurosurgical procedure);
• Are pregnant or trying to become pregnant;
• Have a weight or girth preventing them from entering the MR magnet bore;
• Are unable to understand or unwilling to provide written informed consent for this study.