An updated radiosynthesis of [18F]AV1451 for tau PET imaging

Abstract

Background: [¹⁸F]AV1451 is a commonly used radiotracer for imaging tau deposits in Alzheimer's disease (AD) and related non-AD tauopathies. Existing radiosyntheses of [¹⁸F]AV1451 require complex purifications to provide doses suitable for use in clinical imaging studies. To address this issue, we have modified the synthesis of [¹⁸F]AV1451 to use only 0.5 mg precursor, optimized the Boc-deprotection step and developed a simplified method for HPLC purification of the radiotracer.

Results: An optimized [¹⁸F]AV1451 synthesis using a TRACERLab FX_FN module led to high radiochemical yield (202 ± 57 mCi per synthesis) and doses with excellent radiochemical purity (98 ± 1%) and good specific activity (2521 ± 623 Ci/mmol).

Conclusion: An updated and operationally simple synthesis of [¹⁸F]AV1451 has been developed that is fully automated and prepares radiotracer doses suitable for use in clinical tau PET studies.

Keywords: Automated radiosynthesis; Brain PET; Flortaucipir F18; Fluorine-18 radiochemistry; Tau imaging; [18F]T807.