Brain kinetics of the new selective serotonin transporter tracer [(123)I]ADAM in healthy young adults.
Recently, the tracer (123)I-2-([2-({dimethylamino}methyl)phenyl]thio)-5-iodophenylamine ([(123)I]ADAM) has been developed for selective imaging of serotonin transporters (SERTs) with single photon emission computed tomography (SPECT). The purpose of this study was to develop an [(123)I]ADAM SPECT protocol for clinical studies in young adults.


METHODS
We examined the time course of [(123)I]ADAM binding to central SERTs in eight healthy young volunteers up to 6 h postinjection.


RESULTS
We found that the time of peak-specific [(123)I]ADAM binding was highly variable among subjects, but specific binding in the SERT-rich (hypo)thalamus peaked within 5 h postinjection in all subjects. Moreover, in this brain area, binding ratios of specific to nonspecific binding did not significantly change between 3 and 6 h postinjection, and peaked 5 h postinjection.


CONCLUSIONS
Five hours postinjection may be optimal for single-scan [(123)I]ADAM SPECT studies in humans, but more work is needed to assess the accuracy of the 5-h tissue ratio as a measure of SERT in the brain.
Department of Nuclear Medicine, Academic Medical Center, University of Amsterdam, 1105 AZ Amsterdam, The Netherlands. j.booij@amc.uva.nl
Jan
J
Booij
Maartje M L
MM
de Win
D000328:Adult; D001921:Brain / Q000000981:diagnostic imaging* / Q000378:metabolism*; D002928:Cinanserin / Q000031:analogs & derivatives* / Q000493:pharmacokinetics; D005260:Female; D006801:Humans; D007700:Kinetics; D008297:Male; D008657:Metabolic Clearance Rate; D009928:Organ Specificity; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D012016:Reference Values; D050486:Serotonin Plasma Membrane Transport Proteins / Q000378:metabolism*; D014018:Tissue Distribution; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*
C413491:2-((2-((dimethylamino)methyl)phenyl)thio)-5-iodophenylamine; D019275:Radiopharmaceuticals; D050486:Serotonin Plasma Membrane Transport Proteins; D002928:Cinanserin