Oral administration of 2H9-choline at human dose for deuterium metabolic imaging of brain tumors

Motivation: A need for robust metabolic imaging methods to characterize brain tumor lesions. Goal(s): Explore the potential of oral (PO) deuterated choline at human-recommended doses as a safe alternative to intravenous (IV) infusion, and identify the metabolites contributing to the signal observed in vivo. Approach: Rat orthotopic glioblastoma models were administered 2H9-choline IV or PO. Deuterium metabolic imaging (DMI) was performed in vivo, and tumor tissue extracts were analyzed using pulse-acquire 2H, and 1H-14N HSQC NMR. Results: PO 2H9-choline administration provided similar tumor-to-brain image contrast as IV, with the signal originating primarily from phosphocholine and glycerophosphocholine. Impact: Our results indicate that a lower dose of orally provided deuterated choline generated comparable tumor-to-brain contrast to IV administration, facilitating the potential clinical translation of DMI of deuterated choline.