Medicinal Chemistry strategies for PET tracer discovery.

The detection of gamma rays, resulting from decay of positron emitting isotopes, allows exquisitely sensitive detection of probes radiolabeled with such isotopes. These probes can be designed for high affinity binding to specific molecular targets and be used as tools in the early development of drugs, particularly for neuropsychiatric disorders. Availability of novel tracers requires dedicated resources and selection assays. Many of the selection assays are similar to those used for discovery of clinical compounds, although the distribution and clearance of target specific radioligands requires different in vitro and in vivo methods and new derivatives.