Assessing neuroreceptor occupancy by continuous infusion of carbon-11 labeled radioligands.
In carbon-11 labeled radiotracer studies of neuroreceptors in the brain, a state of practical equilibrium, monitored with a simple dual-probe detector system, was achieved by injection of a bolus of tracer followed by a continuous infusion of the tracer. After investigating several different bolus-to-infusion activity ratios, we observed that a practical equilibrium state could be achieved with a slope of 0.02+/-0.001 cpsxkg/microCi/min for [11C]carfentanil studies in normal human beings. The usefulness of this approach to assess neuroreceptor occupancy was demonstrated in two cases.
Kao
P F
PF
Department of Nuclear Medicine, Chang Gung Memorial Hospital, 199 Tung Hwa North Road, Taipei, Taiwan, R.O.C.
Kim
S
S
Wagner
H N
HN
Lever
J R
JR
Ravert
H T
HT
Dannals
R F
RF
D000328:Adult; D001921:Brain / Q000000981:diagnostic imaging*; D002250:Carbon Radioisotopes; D018491:Dopamine Agonists; D018492:Dopamine Antagonists; D005283:Fentanyl / Q000031:analogs & derivatives; D006801:Humans; D007260:Infusion Pumps; D008297:Male; D020891:Raclopride; D011869:Radioligand Assay / Q000379:methods; D011877:Radionuclide Imaging; D011957:Receptors, Opioid / Q000032:analysis*; D012457:Salicylamides; D013134:Spiperone / Q000031:analogs & derivatives
D002250:Carbon Radioisotopes; D018491:Dopamine Agonists; D018492:Dopamine Antagonists; D011957:Receptors, Opioid; D012457:Salicylamides; D020891:Raclopride; D013134:Spiperone; C039167:3-N-methylspiperone; C017114:carfentanil; D005283:Fentanyl