title: FDA responds to Marcus letter requesting clarification of policies.
authors.affiliation: Center for Drug Evaluation and Review. Food and Drug Administration
authors.forename: P
authors.initials: P
authors.lastname: Botstein
mesh_terms: D011868:Radioisotopes; D014055:Tomography, Emission-Computed; D014481:United States; D014486:United States Food and Drug Administration
chemical_list: D011868:Radioisotopes