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A Simple Target for the Production of Aqueous [¹⁸F] Fluoride Ion Using [¹⁸O] Oxygen Gas--PETNet Pharmaceuticals, Inc., 810 Innovation Drive, Knoxville, TN  37932; 423-218-2542

Dr. Henry C. Padgett, Principal Investigator, henry.padgett@petnetpharmaceutical.com 

Mr. Hank Chilton, Business Official, hank.chilton@petnetpharmaceutical.com 

DOE Grant No. DE-FG02-00ER83066

Amount:  $725,000

Positron emission tomography (PET) is a non-invasive functional imaging technique that measures biochemical/physiological parameters using radiopharmaceuticals labeled with positron-emitting radioisotopes within the human body.  The development of a reliable, high yield, and economical method for the cyclotron-produced radioisotope fluorine-18 in the form of [¹⁸F] fluoride ion would be beneficial for the growth and increased utilization of PET.  This project will develop a practical and reliable method for the use of gaseous [¹⁸O] oxygen gas as the target material for aqueous [¹⁸F] fluoride ion production.  This target offers two important advantages over the current liquid target method: (1) gas targets are able to withstand relatively higher beam currents than liquid targets giving higher yields, and (2) the expensive enriched oxygen-18 gas target material can be more efficiently recovered after the bombardment and received for subsequent runs.  In Phase I, a prototype [¹⁸O]oxygen gas target was designed, constructed, and tested with a manually-operated target support unit (TSU) and was shown to produce aqueous [¹⁸F] fluoride ion in good yield.  The TSU allows the cryogenic recovery and recycling of the enriched [¹⁸O]oxygen gas.  The problem of combining elements of both a high-pressure gas target for the bombardment and a liquid target for the product delivery was solved.  Phase II will design and construct a fully functional prototype high-current target and TSU that will be used for automated operations on the current generation of biomedical cyclotrons.

Commercial Applications and Other Benefits as described by the awardee: New commercial suppliers and distributors of PET radiopharmaceuticals are being announced regularly as are new medical imaging devices that require these positron-emitter labeled radiotracers.  The new target should result in a reliable, high-yield, economical method becoming the new standard method for the production of fluorine-18 radiopharmaceuticals for PET in clinical and research studies.