Special radionuclide production activities – recent developments at QST and throughout Japan

National Institutes for Quantum Science and Technology (QST), formerly known as the National Institute of Radiological Sciences (NIRS), has been engaged in work on radiopharmaceutical science using cyclotrons since 1974. Eight pioneering researchers founded the basis of this field of research at NIRS, and to the present, many researchers and technicians have accumulated both scientific and technical achievements, as well as inherited the spirit of research. Besides, in recent years, we have developed production systems with AVF-930 cyclotron for various ‘non-standard’ radioisotopes applied in both diagnosis and therapy. Here, we review the past 50 years of our activities on radioisotope and radiopharmaceutical development, as well as more recent activities.

Radiosyntheses of two positron emission tomography probes: [11C]Oseltamivir and its active metabolite [11C]Ro 64-0802

Oseltamivir phosphate (Tamiflu, 1.H(3)PO(4) is an orally active anti-influenza drug, which is hydrolyzed by esterase to its carboxylate metabolite Ro 64-0802 (2) with potent activity inhibiting neuraminidase. In this study, for the first time, we synthesized carbon-11-labeled oseltamivir ([(11)C]1) and Ro 64-0802 ([(11)C]2) as two novel positron emission tomography probes and demonstrated that [(11)C]1 had twofold higher radioactivity concentration in the mouse brains than [(11)C]2.