External Tandem Target System for Efficient Production of Short-Lived Positron Emitting Radionuclides

Recent developments in radiopharmaceutical chemistry allow the incorporation of short-lived, positron-emitting radionuclides into a variety of compounds which when used with a positron emission tomograph provide a means of monitoring physiological disorders by a standard technique. To effectively meet the increased "in-house" clinical demands while maintaining a production schedule, a tandem target was designed and has been installed for the simultaneous "on-line" preparation of oxygen-15 labelled compounds such as CO215, H2O15; and nitrogen-13 labelled compounds such as 13NH3, 13N2O, and 13N2. The processing time required for the synthesis of the nitrogen-13 products as compared to the essentially instantaneous formation of oxygen-15 labelled compounds has provided the necessary time delay for clinical utilization. The characteristics of this external tandem target system as well as the automation for the dual processing will be presented.