Extraction of residual 18F-fluoride for PET bone scan simultaneously with the synthesis of 18F-FDG using Explora synthesis module in single run of cyclotron with minimal radiation exposure

1189 Objectives The objective of this study was to test a production method for 18F-fluoride ion simultaneously with the synthesis of 18F-FDG by using Explora FDG-4 chemistry module in a single run of cyclotron. Methods 18 O water irradiated by protons to produce 18 F ion in an 11 MeV Medical Cyclotron.18F-fluoride was transferred from target to trap and release column of first Explora FDG-4 module through V-vial. Residual F-18 in the V-Vial was transferred to the second Explora module at the same time and this 18F-fluoride ion was trapped in the trap and release column of second Explora. Trap and release column removed the silver content coming from the silver target. Trapped 18F- fluoride ion was eluted with eluting agent (mixture of K222, K2CO3, water and acetonitrile) and transferred to a sterile empty production vial in the hot cell through reaction vessels after filtering through a Millipore Milex 0.22µm GS vented filter. Cation exchange resin used for removal of K222. Dilution was done with normal saline (0.9% NS) to form Sodium Fluoride. Mean total purification time for was 8 minutes. Quality control was done as per to USP guide lines (clarity, isotonicity, pH, radiochemical purity, radionuclide purity by half life). Results Results of quality control satisfied all parameters prescribed by USP. The level of K222 in 18F-Fluoride was ≤ 2 µg/ml in all 68 runs using this protocol. Mean pH of 18F-Fluoride was 6.5±1.Time required for the purification of 18F-Fluoride and synthesis of 18F-FDG were 8 ±1.24 (Mean±SD) and 42±2.44 (Mean±SD). The exposure rate around the hot cell ranged between 0.3-0.6 µSv/hr. Conclusions This is a simple and cost effective method to produce 18F- NaF for PET bone scan simultaneously with 18F-FDG in a single run of cyclotron with minimal radiation exposure to the radiopharmacist.