Time

anissueproudlyentitled“Clinical PET: Its Time Has Come.―Now, more than two years later, it appears that this proclamationmay have been premature.This is not because of any deficiencies in the science underlying positron emission tomography (PET), nor because PET has insufficientchin lea! potential; both the science and po tential of PET were solidly docu mented in April 1991. Rather, the time for clinical PET has not yet arrived because of the practical issue of ob taming reimbursement for PET proce dures, and this issue is in turn tightly coupled to the regulation of PET ra diopharmaceuticals. Thus, progress towards achieving the potential of clinical PET has become mired in the alphabetsoup HCFA, HIAA, OHTA, FDA, IND, NDA, ANDA and, poten tially the worst, CGMP*. Despite vociferous protests by the nuclear medicine community, the FDA maintains its position that it will regulate PET radiopharmaceuticals (1,2). Today, in April 1993, there is only one FDA approved PET radio pharmaceutical,and that is the chem ically simple 82Rb ion which is pro vided by the easily regulated, commercial 82Sr/€2Rb generator. The chemically more complicated mole cule †̃8F-FDGis the workhorse of PET, and the PET community has been trying since 1990to obtain FDA approval for it. The original NDA, filed on February 15, 1991, was deemed to have serious deficiencies and an improved, revised NDA was