Simple automated preparation of O-[11C]methyl-l-tyrosine for routine clinical use

The previously reported preparation of O-[11C]methyl-l-tyrosine ([11C]MT), a promising tumor imaging agent, has been now considerably simplified and automated. Main changes were the use of [11C]methyl iodide ([11C]MeI) in the reaction with l-tyrosine disodium and the use of solid phase extraction on commercially available cartridges instead of HPLC for the final purification. An injectable saline solution of [11C]MT was obtained within 30 min after EOB with radiochemical yield of ca. 60% (decay-corrected, based on [11C]MeI). Radiochemical purity was over 97%. The automated preparation was carried out using a miniature module employing manifold valves.