Experimental production and initial imaging of [18F]-14-Fluoro-6-thia-heptadecanoic acid ([18F]-FTHA) for myocardial performance

[18F]-6-thia-14-fluoro-heptadecanoic acid 3b, a free fatty acid, has been used in myocardial PET imaging. In order to establish an automated synthesis module for routine production in the country, a study performed for optimization of the production conditions as well as making modifications. [18F] Benzyl-14-Fluoro-6-thia-heptadecanoate 2b was prepared in no-carrier-added (n.c.a) form from Benzyl-14-tosyloxy-6-thia-heptadecanoate 1 in one step at 90C in Kryptofix2.2.2/[18F] and acetonitrile as the solvent followed by Silica column chromatography. The radiolabeled ester 2 was then hydrolyzed to yield [18F]-6-thia-14-fluoro-heptadecanoic 3b. The final solution was concentrated using C18 SPE system and administered to normal rats for biodistribution as well as co-incidence imaging studies. The synthesis took 15 min with overall radiochemical yield of 15-25% (EOS) and chemical-radiochemical purity more than 94%. Automation was performed using a two-pot synthesis. The best imaging time was shown to be 140-180 minutes post injection. Using this procedure a fast, reliable, automated synthesis for the cordial PET tracer, i.e. [18F]-FTHA can be obtained without HPLC purification step.