Hyperpolarized 13C-MRI in Patients With Hepatocellular Carcinoma Undergoing Radiotherapy, Atezolizumab, and Bevacizumab

Increased pyruvate-to-lactate conversion is a hallmark of HCC metabolism. In parallel, activation of pro-inflammatory immune cells triggers a metabolic switch towards anaerobic glycolysis. Hyperpolarized carbon-13 (13C) pyruvate MRI is a state-of-the-art non-invasive imaging method that offers real-time insights into tissue metabolism. Recent studies have demonstrated its promising potential in predicting responses to radiotherapy and immunotherapy in solid tumors, given the significance of pyruvate as a downstream metabolite in glycolysis. However, its application in assessing treatment response in hepatocellular carcinoma (HCC) patients remains unclear. The establishment of quantitative imaging biomarkers for predicting responses to radio-immunotherapy is an unmet need in the management of HCC patients. While radiotherapy (RT) effectively controls localized tumors through the induction of unrepairable DNA double-stranded breaks (DSBs) and cell death, its therapeutic efficacy on distal, non-irradiated tumor cells is limited, with out-of-field recurrence being a common pattern of failure in HCC patients treated with high-dose irradiation. Atezolizumab (anti-programmed death-ligand 1; anti-PD-L1) in conjunction with bevacizumab (anti-vascular endothelial growth factor; anti-VEGF) has recently emerged as the standard first-line systemic treatment for unresectable hepatocellular carcinoma (HCC). Despite an objective response rate (ORR) of only 27%, the majority of patients succumb to HCC progression and liver failure. Our preclinical study (Hsieh et al., Science Immunology 2022) uncovered that RT, when combined with PD-L1/PD-1 blockade, induces immunogenic cell death and tumor antigen cross-presentation in antigen-presenting cells, enhancing systemic antitumor T cell responses in murine tumor models. Recent retrospective cohorts suggest that RT targeting all hepatic tumors combined with PD-L1/programmed death-1 (PD-1) blockade is associated with an improved ORR and median progression-free survival (PFS) in patients with unresectable HCC, demonstrating a favorable safety profile. The synergistic antitumor effects of this combination therapy with RT, atezolizumab, and bevacizumab have led to its increasing adoption in routine clinical practice. This phase II non-randomized trial aims to prospectively investigate the predictive value of hyperpolarized 13C-MRI, along with comprehensive metabolomics and radiomics analyses, for immune response assessment including tumor control outcomes and toxicity in patients with HCC undergoing radiotherapy, atezolizumab, and bevacizumab.

NCT Number	NCT06605664
Lead Sponsor	Chang Gung Memorial Hospital
Conditions	Hepatocellular Carcinoma (HCC)
Enrollment	45 participants
Start Date	2025-05-01
Primary Completion	2029-06-30 (estimated)
Study Completion	2031-09-30 (estimated)
Updated on ClinicalTrials.gov	2025-05-14