Tracer kinetic modeling of the 5-HT1A receptor ligand [carbonyl-C-11]WAY-100635 for PET

[Carbonyl-C-11]WAY-100635 is a promising PET radioligand for the 5-HT1A rec eptor, having demonstrated more favorable characteristics for in vivo imagi ng than the previously available [O-methyl-C-11]WAY-100635. The current stu dy evaluates different tracer kinetic modelling strategies for the quantifi cation of 5-HT1A receptor binding in human brain. Mathematical modelling of the carbonyl-labeled radiotracer is investigated using compartmental struc tures, including both plasma input and reference tissue approaches. Further more, the application of basis function methods allows for the investigatio n of parametric imaging, providing functional maps of both delivery and bin ding of the radioligand. Parameter estimates of binding from normal volunte ers indicate a low intra- versus a high intersubject variability. It is con cluded that a simplified reference tissue approach may be used to quantify 5-HT1A binding either in terms of ROI data or as parametric images. (C) 199 8 Academic Press.