Progress in positron emission tomography (PET)-based diagnostic imaging and clinical research depends in large part on development of the radiopharmaceuticals that provide the basis for PET. Currently, the most widely used radiopharmaceutical in PET is [18F]-fluorodeoxyglucose (FDG), an analogue of glucose labeled with the positron emitter 18F. This allows [18F]FDG to accumulate in sites with robust glucose metabolism, facilitating the evaluation of malignancies and neural activity in the brain, where glucose is the primary energy source. Other radiopharmaceuticals used in clinical settings include those for analyzing neural receptors in the brain and for detecting amyloid beta-protein, which accumulates in patients with Alzheimer-type dementia.
The steps involved in radiopharmaceutical manufacture-production of the radioisotope in an accelerator, radiolabeling, purification, and formulation into an injection and other dosage forms-must be completed quickly. As positron emitters decay under short half-lives, the manufacture of radiopharmaceuticals has long been known as a battle against time.
The Research Team for Neuroimaging has developed 48 radiopharmaceuticals that have been approved for clinical use. This number includes radiopharmaceuticals developed by the former Positron Medical Center, which was established in 1990. Nine of these compounds were first-in-human radiopharmaceuticals. Medical institutions that use these new compounds for clinical purposes do so according to their respective rules and processes.
Increasingly, PET radiopharmaceuticals must be manufactured under systems accredited by the Japanese Society of Nuclear Medicine and Good Manufacturing Practice for investigational products. Our medical institution proactively implements these systems for use in clinical trials and global research.