ASSESSMENT OF F-18 GASEOUS RELEASES DURING THE PRODUCTION OF F-18 FLUORODEOXYGLUCOSE

Fluorodeoxyglucose labeled with F-18 (F-18-FDG) is the most commonly used radiopharmaceutical in positron emission tomography (PET). Fluorine-18-labeled FDG is used as a diagnostic tool in PET studies to monitor the physiology of the brain, diagnose heart function and disease, and to image cancerous tumors. At the University of California, Los Angeles (UCLA), three cyclotrons produce [F-18]-fluoride ion using O-18-enriched water targets. Fluorine-18, which has a half-life of 109.8 min, is produced using an O-18(p, n)F-18 reaction and is chemically processed to yield F-18-FDG. This study presents data which demonstrate that during the radiochemical processes involved in the production of F-18-FDG, gaseous effluent containing F-18 is released. Forty cyclotron production runs with average end of cyclotron bombardment activities of 15.9 +/- 1.88 GBq (430 +/- 50.8 mCi) and end of radiochemical synthesis activities of 5.40 +/- 1.27 GBq (146 +/- 34.3 mCi) yield F-18 gaseous effluent releases ranging from 0 to 2560 MBq (0 to 69.2 mCi) with a mean of 437 MBq (11.8 mCi). Temporal correlation of the F-18 gaseous releases during F-18-FDG radiochemical production has tied the F-18 release to the addition of the glucose precursor (mannotriflate) and ethyl ether in the radiochemical processing. The results are presented in terms of activities released and dilution factors required from the release stack point to maintain controlled (occupational) and uncontrolled (public) area limits in accordance with the recommendations of the International Commission on Radiological Protection and the regulatory requirements of the federal government.