Session S51.4

Automated Synthesis of [11C]Meta-Hydroxyephedrine, a PET Radiopharmaceutical for Studying Sympathetic Innervation in the Heart

F Lodi*, A Rizzello, A Carpinelli, D Di Pierro, G Cicoria,
V Mesisca, M Marengo, S Boschi

Hospital S. Orsola-Malpighi
Bologna, Italy

Objectives: PET imaging of the sympathetic innervation of the heart can involve the labelling of catecholamine analogs (false neurotransmitters) as [11C]meta-hydroxyephedrine ([11C]MHED) which allows the study of adrenergic neurons in heart diseases. Aim of this study was the development of an automatic synthesis program for [11C] MHED using a computer-assisted [11C]methylation module which provides the production of this radiopharmaceutical with reproducible radiochemical yield for cardiological studies in clinical PET.
Methods: Automated synthesis of [11C]MHED was performed in a computer-assisted [11C]methylation module TRACERlab FXC. The [11C]MHED synthesis program was developed by means of dedicated software (GE Healthcare) which automatically controls the analytical steps as well as the registration of the synthesis parameters as temperature, pressure and activity. A graphic representation screen of the process was present allowing the operator to follow the time synthesis course. [11C]MHED was synthesized by [11C] methylation of precursor metaraminol using [11C]CH3I produced by converting [11C]CO2 with gas phase iodination method. [11C]MHED was purified by preparative HPLC included in the module and sterilized by 0.22 µm membrane. Radiochemical purity was evaluated by Radio-HPLC.
Results and Conclusion: Radiochemical yield of [11C]MHED was 12±1% (n=5) (decay corrected referred to the end of bombardment) with an average production of 3.1 GBq for patient administration. Synthesis’ time were 30 min including HPLC purification. Radiochemical purity was always higher than 99%.The automatic synthesis program provides [11C]MHED with reproducible radiochemical yield and high radiochemical purity. The activity produced per synthesis was enough to study 2 patients. These preliminary results show that this computer-assisted approach for the synthesis of radiopharmaceuticals represents a reliable tool for [11C] MHED production in clinical PET.

(Abstract Control Number: 259)