RT Journal Article
SR Electronic
T1 Comparative evaluation of the serotonin transporter tracers [C-11]AFM and [C-11]DASB in humans
JF Journal of Nuclear Medicine
JO J Nucl Med
FD Society of Nuclear Medicine
SP 1205
OP 1205
VO 50
IS supplement 2
A1 Yiyun Huang
A1 Alexander Neumeister
A1 Wendol Williams
A1 Jim Ropchan
A1 David Labaree
A1 Shu-fei Lin
A1 Beata Planeta-Wilson
A1 Rachel Hull
A1 Soheila Najafzadeh
A1 Richard Carson
YR 2009
UL http://jnm.snmjournals.org/content/50/supplement_2/1205.abstract
AB 1205 Objectives The new serotonin transporter (SERT) ligand [C-11]AFM has higher binding affinity in vitro and displays higher specific binding signals than the current standard ligand [C-11]DASB in the baboon brain. A PET imaging study was conducted to compare the imaging qualities of these two tracers in humans. Methods PET imaging was performed on the HRRT scanner. Three healthy subjects were each scanned once with [C-11]AFM and once with [C-11]DASB on the same day. Metabolism of the tracers was analyzed by HPLC. Free fraction in the plasma was measured by ultrafiltration. Imaging data were analyzed using the Simplified Reference Tissue Model (SRTM2). Results In the blood, metabolism was faster and free fraction higher for [C-11]DASB than for [C-11]AFM. In the brain, [C-11]DASB displayed higher uptake and faster kinetics, while [C-11]AFM displayed higher specific binding signals. For [C-11]AFM, the mean binding potentials (BPnd) were 4.3, 2.1, 2.0, 1.9, 1.4, 0.8, respectively, in the raphe, amygdala, putamen, thalamus, caudate, and hippocampus. [C-11]DASB BPnd values were 3.5, 1.5, 1.4, 1.6, 1.0, and 0.6, respectively, in the same regions. In the cortex, [C-11]AFM BPnd were 0.81, 0.56, 0.47, and 0.44 in the anterior cingulate, occipital, temporal, and frontal areas, compared with 0.60, 0.43, 0.37, and 0.35 for [C-11]DASB. On average, [C-11]AFM specific binding was ~30% higher than [C-11]DASB across brain regions. Conclusions In humans, [C-11]AFM provides higher specific binding signals than [C-11]DASB. This study suggests that [C-11]AFM is a superior tracer for PET imaging of the SERT.