[18F]FHBG synthesis and PET imaging

[¹⁸F]FHBG was prepared using the one-pot synthesis method developed from previously published methods ^{47, 48}. Briefly, tosyl-FHBG precursor (2960, ABX, Radeberg, Germany) was radiolabeled using [¹⁸F]KF and Kryptofix 222 complex in DMSO (Sigma-Aldrich), and the protecting groups were hydrolyzed by 1 M HCl. The reaction mixture was neutralized and the final product purified by HPLC. The radiochemical yield was 6 ± 2% (decay corrected) with a radiochemical purity of 95 ± 3% and molar activity > 48.9 GBq/μmol at the end of the synthesis. The [¹⁸F]FHBG solution with 50 mM ammonium acetate, 0.9% NaCl, and 7% ethanol was used for animal experiments.

Rats were anesthetized with 1.5 - 2.5% isoflurane/oxygen and [¹⁸F]FHBG (9.0 ± 2.3 MBq) injected intravenously. Static PET imaging data were acquired over 20 min on micro PET/CT scanners (β- and X-CUBE, MOLECUBES, Gent, Belgium) starting 40 min after injection.