Targetry for the Production of Medical Isotopes

A high-pressure, low volume, cryogenically-cooled gas target has been developed for tandem Van de Graaff production of medical radiotracers. High yields and radionuclidically pure products are made possible by the use of enriched target materials. The inert Kr-81m (t 1/ 2 - 13 sec) from the 80Kr(d,n)81Rb reaction permits continuous administration from a generator for regional pulmonary ventilation studies. Cryo-pumping and reclamation procedures enhance the economic feasibility of using enriched isotopes by minimizing target losses. Direct extrapolation of those techniques to cyclotron targetry is possible. A low-volume, enriched solid target employing the 50Cr(d,n)51Mn reaction has been developed. The mitochondrial concentration of Mn in the heart muscle enables Mn-51 to be used as a myocardial imaging agent.