Differences in metabolic behavior of liver metastases of colorectal carcinoma: [18F]FDG-PET vs. DMI at 7T.

Motivation: [18F]FDG-PET scans of liver metastases of colorectal cancer (LMCRC) show varied metabolic profiles, but are often obscured by physiological liver glucose uptake. Measurement of tumor-specific glucose metabolism by deuterium metabolic imaging (DMI) could improve disease assessment. Goal(s): To explore abberant glucose metabolism in LMCRC by both DMI and [18F]FDG-PET, providing initial insight into their potential complementarity. Approach: Three patients with LMCRC were scanned using [18F]FDG-PET-CT and DMI at 7T. Results: 2H-lactate signals were detected in areas corresponding to increased [18F]FDG-uptake, while no 2H-lactate signal was observed in necrotic tissue. At the same time, 2H-glucose signals were decreased in both active and necrotic lesions. Impact: This study demonstrates that deuterium metabolic imaging can reveal distinct metabolic features in liver metastases of colorectal cancer, complementing [18F]FDG-PET by distinguishing necrotic and active tumor tissue, and thus providing a promising non-invasive tool for metabolic assessment in liver metastases.