Improved automated synthesis of [18F]FINH-Me via direct radio-fluorination and quality control for Aβ-amyloid imaging.

Background: Alzheimer's disease (AD) is a neurological disorder that leads to a loss of cognitive functioning, affecting older people as well as their families. An early detection of AD is therefore crucial to help people maintain mental function, and slow down or delay the symptoms of the disease. Studies have confirmed that the deposition of the amyloid-β peptide in the brain is a central event in AD pathology. An imaging probe for Aβmight provide a useful tool to be used in the diagnosis and monitoring response to therapy of AD.

Methods: This article reports a new AD imaging probe [¹⁸F]FINH-Me, which has a high molar activity for Aβ. Automated synthesis of [¹⁸F]FINH-Me was performed in a single reactor using a two-step procedure; fluorination and hydrolysis. The qualities of this probe were tested, and autoradiography was performed to determine if the probe was bound to the AD sections. And the micro-PET/CT imaging experiment was done to further confirm the combination of the probe and Aβ.

Results: Optimized synthesis of [¹⁸F]FINH-Me was achieved in 90 minutes. The probe was then scaled up for large-batch production to generate 18.79-23.53 GBq of [¹⁸F]FINH-Me at EOS (N.=15) in high molar activity (79.9-122 GBq/µmol, at EOS, N.=15). In the AD brain sections, the radio activity was concentrated at the hippocampus and the temporal lobe area.

Conclusions: [¹⁸F]FINH-Me is a promising PET probe to be used in AD diagnose.