The future of positron emission tomography in clinical medicine and the impact of drug regulation.

Positron emission tomography (PET) was initially developed as a research tool for evaluating normal and abnormal physiology. Subsequently, the potential clinical utility of PET was recognized, and several specific clinical indications have been defined. PET has been demonstrated to be clinically useful in evaluating certain disorders of the brain and heart. PET holds significant promise for use in the evaluation of psychiatric illness and in multiple aspects of evaluation of malignancy. A major limiting factor for the growth of clinical PET is the absence of policies for reimbursement by third-party payers. Although rubidium-82 chloride is approved by the Food and Drug Administration (FDA), the lack of FDA approval of fluorine-18 2-fluoro-2-deoxyglucose (FDG) is hampering reimbursement for PET studies. The jurisdiction of the FDA over cyclotron-produced PET radiopharmaceuticals synthesized and used on site is a matter of debate because these drugs are not introduced into interstate commerce and because these activities appear to be permissible under certain exemptions in the Federal Food, Drug, and Cosmetic Act relating to the practices of medicine and pharmacy. The jurisdictional authority of the FDA in regulating these radiopharmaceuticals would be established with certainty only through litigation, but no individual or organization has elected to challenge the FDA at this time. The Institute for Clinical PET (ICP) is developing a Drug Master File that can be used in support of site-specific New Drug Applications (NDAs) for cyclotron-produced radiopharmaceuticals by any organization desiring an NDA. The ICP is optimistic that this method of obtaining FDA-approval of FDG and other cyclotron-produced PET radiopharmaceuticals will be successful and beneficial to sites using PET clinically.