Dopamine transporter binding in rat striatum: a comparison of [O-methyl-11C]β-CFT and [N-methyl-11C]β-CFT

Striatal dopamine transporter availability in unmedicated bipolar disorder

“…The cerebellum was chosen as the reference region, as it has very little dopaminergic innervation (44). This general quantitative approach is well‐accepted for dopaminergic ligands, including [ 11 C]CFT (31–34, 40) Data analyses were conducted with a ROI approach.…”

“…Image processing was similar to what has been described in previous studies (40,41). All image processing was conducted with Statistical Parametric Mapping software, version 5 (http://www.fil.…”

“…PET imaging. [ O ‐methyl‐ 11 C]β‐CFT ([ 11 C]CFT) was synthesized by esterification of β‐CFT‐acid with [ 11 C]methyl triflate under basic conditions, with 40–50% decay corrected radiochemical yields as previously described (30, 40). The [ 11 C]CFT was of high radiochemical purity (> 99%), and high specific activity (259–555 GBq/μmol at end of bombardment).…”

Synthesis, Fluorine-18 Radiolabeling, and Biological Evaluation of N-((E)-4-Fluorobut-2-en-1-yl)-2β-carbomethoxy-3β-(4′-halophenyl)nortropanes: Candidate Radioligands for In Vivo Imaging of the Brain Dopamine Transporter with Positron Emission Tomography

“…The DAT is also the target of several drugs of abuse including cocaine, , amphetamines, and MDMA (ecstasy), and this has led to the search for compounds that can be employed as potential cocaine addiction therapeutics. , From this research evolved the 3β-phenyl tropane class of DAT ligands of which compounds 1 − 6 were the first to be prepared. − These compounds have since been exploited for PET imaging due to the ability to radiolabel with carbon-11 on either the N -methyl group or the O -methyl ester. − Carbon-11 has a half-life of 20.4 min, which limits the use of 11 C-labeled tracers to the location where they are prepared and to imaging sessions of about 2 h. Fluorine-18 has a half-life of 109.8 min, which allows for longer radiosynthesis times and imaging sessions, and also for the transport of the 18 F radiotracer to PET imaging facilities that do not have onsite cyclotrons. Additionally, 18 F positrons have a lower maximum energy (0.64 MeV) than 11 C positrons (0.97 MeV), which therefore deposits less energy into tissue and also results in a positron with a shorter linear range which allows for higher spatial resolution. , These physical properties of 18 F are serendipitous due to the increasingly valuable role that 19 F is playing in medicinal chemistry, − and a variety of synthetic methods have now been developed to incorporate 18 F or 19 F into molecules. − …”

“…[21][22][23][24] These compounds have since been exploited for PET imaging due to the ability to radiolabel with carbon-11 on either the N-methyl group or the O-methyl ester. [25][26][27][28] Carbon-11 has a half-life of 20.4 min, which limits the use of 11 C-labeled tracers to the location where they are prepared and to imaging sessions of about 2 h. Fluorine-18 has a half-life of 109.8 min, which allows for longer radiosynthesis times and imaging sessions, and also for the transport of the 18 F radiotracer to PET imaging facilities that do not have onsite cyclotrons. Additionally, 18 F positrons have a lower maximum energy (0.64 MeV) 29 than 11 C positrons (0.97 MeV), which therefore deposits less energy into tissue and also results in a positron with a shorter linear range which allows for higher spatial resolution.…”