Article ID Journal Published Year Pages File Type
1879411 Applied Radiation and Isotopes 2009 6 Pages PDF
Abstract

The radioligand 3-(4-(3-[18F]fluoropropylthio)-1,2,5-thiadiazol-3-yl)-1-methyl-1,2,5,6-tetrahydropyridine ([18F]FP-TZTP) is an agonist with specificity towards subtype 2 of muscarinic acetylcholine (M2) receptors. It is currently the only radiotracer available for imaging M2 receptors in human subjects with positron emission tomography. The present study reports on an improved method for the synthesis of [18F]FP-TZTP, automated using a GE TRACERlab™ FXFN radiosynthesis module. A key facet was the use of a new precursor, 3-(4-(1-methyl-1,2,5,6-tetrahydropyridin-3-yl)-1,2,5-thiadiazol-3-ylthio)propyl 4-methylbenzenesulfonate. The precursor was fluorinated via nucleophilic displacement of the tosyloxy group by potassium cryptand [18F]fluoride (K[18F]/K222) in CH3CN at 80 °C for 5 min, and purified by HPLC. Formulated [18F]FP-TZTP was prepared in an uncorrected radiochemical yield of 29±4%, with a specific activity of 138±41 GBq/μmol (3732±1109 mCi/μmol) at the end of synthesis (35 min; n=3). This methodology offers higher yields, faster synthesis times, an optimized precursor, and simpler automation than previously reported.

Related Topics
Physical Sciences and Engineering Physics and Astronomy Radiation
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