PET Reporter Probes for Brain Imaging of Transduced Gene and Cell Expression: Status and Challenges

Gene therapy and cell transduction are gaining interest as therapeutic strategies for neurological and psychiatric disorders. Positron emission tomography (PET) has been established as a uniquely powerful modality for brain molecular imaging in vivo. The utility of PET depends on the development and application of suitably specific radiotracers and/or reporter probes. PET probes are potentially useful to confirm the success of gene therapy or cell transduction without the need for brain biopsy or necroscopy. Probes are needed to target proteins expressed by specific exogenous transgenes or cells and could play a crucial role in elucidating neurobiological mechanisms and in longitudinal tracking of expression for therapeutic applications. This perspective article describes the current status and ongoing challenges for the design and development of PET reporter probes for verifying the expression of reporter genes and cells in the brain. Radiochemical aspects, applications, and translational challenges for diagnostic and therapeutic interventions are highlighted.