Simplified labeling approach for synthesizing 3′-deoxy-3′-[18F] fluorothymidine ([18F] FLT)

HJ Machulla, A Blocher, M Kuntzsch, M Piert… - … of Radioanalytical and …, 2000 - Springer
HJ Machulla, A Blocher, M Kuntzsch, M Piert, R Wei, JR Grierson
Journal of Radioanalytical and Nuclear Chemistry, 2000Springer
Abstract [18 F] FLT (3′-deoxy-3′-[18 F] fluorothymidine) turned out to be a tracer
particularly suitable for PET imaging of tumor proliferation because of lacking degradation in
vivo. To facilitate clinical studies with [18 F] FLT, we investigated two new easily accessible
precursors, 2, 3′-anhydrothymidine (AThy) and 5′-O-(4, 4′-dimethoxytriphenylmethyl)-2,
3′-anhydrothymidine (DMTThy), using a common approach for introducing the label with
nucleophilic [18 F] fluoride. Radiochemical yields were determined in dependence on …
Abstract
[18F]FLT (3′-deoxy-3′-[18F]fluorothymidine) turned out to be a tracer particularly suitable for PET imaging of tumor proliferation because of lacking degradation in vivo. To facilitate clinical studies with [18F]FLT, we investigated two new easily accessible precursors, 2,3′-anhydrothymidine (AThy) and 5′-O-(4,4′-dimethoxytriphenylmethyl)-2,3′-anhydrothymidine (DMTThy), using a common approach for introducing the label with nucleophilic [18F]fluoride. Radiochemical yields were determined in dependence on substrate concentration, reaction time and temperature. In the case of AThy (10 mg), best FLT yields were 5.3%±1.2 (130 °C, 30 min). Labeling of DMTThy (10 mg) gave 14.3%±3.3 at 160 °C within 10 minutes. Starting with an aqueous solution of 20 GBq [18F]fluoride the new method allows to produce 1.3 GBq [18F]FLT within 90 minutes ready for intravenous injection. The new labeling procedures allow [18F]FLT synthesis without lengthy preparation of the precursor and with high reproducibility mandatory for clinical application.
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