Carbon-11 Labeled Tracers for In Vivo Imaging of P-Glycoprotein Function: Kinetics, Advantages and Disadvantages

P-glycoprotein (P-gp) is a drug efflux transporter with broad substrate specificity localized in the blood-brain barrier and in several peripheral organs. In order to understand the role of P-gp in physiological and patho-physiological conditions, several carbon-11 labelled P-gp tracers have been developed and validated. This review provides an overview of the spectrum of radiopharmaceuticals that is available for this purpose. A short overview of the physiology of the blood-brain barrier in health and disease is also provided. Tracer kinetic modelling for quantitative analysis of P-gp function and expression is highlighted, and the advantages and disadvantages of the various tracers are discussed.