Radioligand development for molecular imaging of the central nervous system with positron emission tomography

Positron emission tomography (PET) is routinely used to support the development of drugs to treat neurological and psychiatric disorders. PET radioligands must not only be selective for the target of interest but must also possess a range of physicochemical and pharmacological characteristics that allow them to be radiolabelled with short-lived positron-emitting isotopes, safely administered to humans, and for the degree of target binding to be quantified in vivo. We review the ligand development process, including target selection, radioligand discovery (in vitro and preclinical evaluation), radiochemistry and evaluation in humans.