Preclinical and clinical evaluation of -[C]methyl--tyrosine for tumor imaging by positron emission tomography

We performed preclinical and clinical studies of O-[11C]methyl-l-tyrosine, a potential tracer for imaging amino acid transport of tumors by positron emission tomography (PET). Examinations of the radiation-absorbed dose by O-[11C]methyl-l-tyrosine and the acute toxicity and mutagenicity of O-methyl-l-tyrosine showed suitability of the tracer for clinical use. The whole-body imaging of monkeys and healthy humans by PET showed low uptake of O-[11C]methyl-l-tyrosine in all normal organs except for the urinary track and bladder, suggesting that the O-[11C]methyl-l-tyrosine PET has the potential for tumor imaging in the whole-body. Finally, the brain tumor imaging was preliminarily demonstrated.