[Applications of positron emission tomography (PET) to the measurement of regional cerebral pharmacokinetics]

Abstract

Positron emission tomography (PET) has not only a variety of applications to functional diagnostics using methods of nuclear medicine and for the investigation of pathophysiological processes, it also offers new possibilities for pharmacology. As PET is able to quantitatively record "from outside" the regional concentration of a positron emitter in a living primate, the distribution and kinetics of a labelled drug at the site of action can be determined non-invasively. This is always the case if the research substance can be labelled practically carrier-free with a short-lived positron emitter such as 11C (T1/2 = 20 min) or if applicable 18F (T1/2 = 110 min). The quantities applied in this case are so small that pharmacodynamic effects do not occur. Therefore, this method is particularly suitable for measuring in vivo the regional cerebral pharmacokinetics of centrally acting drugs in humans.