Fully automated production of [11C]PiB for clinical use on Trasis-AllinOne synthesizer module

Abstract

Pittsburgh compound B ([¹¹C]PiB) was the first broadly applied radiotracer with specificity for amyloid-β (Aβ) peptide aggregates in the brain and has since been established as the gold standard for positron emission tomography (PET) employed for clinical in vivo imaging of Aβ plaques, used for imaging applications of Alzheimer's disease (AD), related dementia, and other tauopathies. The use of [¹¹C]PiB for routine PET studies is dependent on the production capabilities of each radiochemistry laboratory, subsequently a continuous effort is made to develop suitable and sustainable methods on a variety of auto synthesis platforms. Here we report a fully automated, multi-step radio synthesis, purification, and reformulation of [¹¹C]PiB for PET imaging using the Trasis AllinOne synthesis unit, a commonly used commercial radiochemistry module. We performed three validation runs to evaluate the reproducibility and to verify that the acceptable criteria were met for the release of clinical-grade [¹¹C]PiB using a Trasis AllinOne auto radiosynthesis unit. Solid phase supported radiolabeling was performed through the capture of precursor (6-OH-BTA-0) on a C18 solid phase extraction (SPE) cartridge and subsequent flushing of gaseous [¹¹C]Methyl triflate(MeOTf) through the Sep-Pak for carbon-11 (¹¹C) N-methylation. Starting with 92.5 GBq [¹¹C]CO₂, [¹¹C]PiB synthesis was completed in approximately 25 min after cyclotron end of bombardment with an injectable dose >7.0 GBq at end of the synthesis. The radiopharmaceutical product met all quality control criteria and specifications for use in human studies.

Keywords: (11)C-radiotracer; Alzheimer's disease (AD); Automated radiosynthesis; Clinical radiochemistry; Positron emission tomography (PET); [(11)C]PiB.