Improved Radiochemical Yields, Reliability and Improvement of Domestic [ 18 F]FDG Auto Synthesizer J. H. PARK, K.S. IM, H.J. Lee, B.C. Lee, I.W Lee Department of Nuclear Medicine, Seoul National University Bundang Hospital

INTRODUCTION [ 18 F]FDG is the most widely used PET radiopharmaceutical. Popularization of PET/CT scanners and cyclotrons in Korea Two [ 18 F]FDG modules made in KIRAMS was installed in Seoul National University Bundang Hospital.

METHOD AND MATARIALS  Main Frame: Aluminum profile base To prevent and reduce anodizing oxidation scratch  Fitting materials ; PEEK polymer Resistant to chemical: Acid and Base

SYNTHETIC FACTORS IN MODULE Variable setting tab: reaction time, temperature Synthetic factors: elapsed time, step time, temperature, reaction vessel pressure The Pressure, time and temperature can affect FDG production yield

FDG SYNTHESIS PROTOCOLS 18 F capture in the QMA from cyclotron Elution by tetrabutylammonium bicarbonate (TBAB) & Acetonitrile drying Fluorination of Precursor (Mannose Triflate) Hydrolysis (HCl) Purification by ion retardation column and Sep-Pak cartridge

DOMESTIC FDG SYNTHESIZER MODULE FDG yield: Domestic module (40-45%) vs Foreign Module (> 60%) Ideal FDG synthesis Condition Drying test Control of FDG synthetic factors Monitoring of synthesis process CCTV and final FDG activity Volumetric vial, Recovery vial Protection of vacuum pump: Liquid nitrogen Trap Charcoal filter, Base vacuum guard filter Need to optimize the FDG yield in domestic FDG Module

Flow Chart of Modified Module Precursor+ ACN HCl Purification Cartridge Reaction vial Liquid nitrogen trap 2 mL Recovery vial Volumetric vial V14 FDG FDG module QMA Base vacuum guard filter Charcoal filter Vacuum: -75 psi F-18

EVAPORATION TEST Numerous evaporation tests were performed to find out the best condition (TBAB, Temp.) 1 TBAB 0.87mL (Syringe) 2 TBAB 0.87mL (Micro pipette) 68 ℃,180 sec. TBAB, ACN, Drying 102 ℃ 100 sec. TBAB, ACN Drying, 100 ℃ 50 sec. ACN Drying

MICRO PIPETTING DIFFERENT TEMPATURE Different Synthetic Temperature Elution Step (Residual 18 F Activity) 0.5mL  0.6mL(24.7%)  0.7  0.72mL (6%) To reduce average error for 18 F elution  Accurate 0.72mL TBAB dispensing by Micro Pipette

Other Accessories (1) Volumetric indicator vial ( 18 O water recovery): (A)  To monitor delivered water volume (2mL) leaking in the line from cyclotron Recovery vial (B)  To recover loss of FDG activity (A) (B)

Other Accessories (2) Classical liquid nitrogen gas trap : need to be refilled every 2 hours (A) Life Cycle  Charcoal Filter : 3 months (B)  Vacuum Guard Filter: 2 months (C) Suction Side Separator: Organic Solvent (D) (A) (B) (C) (D)

RESULTS (1) Deliver typeMicro PipetteSyringe (1mL) 5.5 ±1.7%7.6 ± 2.8% (Residual F-18 Activity in QMA after Elution step) Comparison of Micro Pipette and Syringe TBAB reagent delivering

90 sec.100 sec.105 sec. 55±3.6% (n=11)58±2.6% (n=10)53±1.4% (n=2) Drying time before fluorination ( 102 ℃ ) 80 ℃ 83 ℃ 85 ℃ 51.6±4.1%(n=3)60±2.5%(n=33)53.9±4.5%(n=14) Fluorination temperature RESULTS (2)

RESULTS (3) 95 ℃ 100 ℃ 105 ℃ 54.3±2.5%(n=3)57.8±2.6%(n=19)53.7±3.3%(n=11) Drying temperature after fluorination FDG yield for 3 months InstallationJuneJulyAugust 45±5% 58±2.6% (n=19) 58±2.9% (n=14) 60±2.5% (n=17)

QUALITY CONTROL OF FDG Q.C itemValueRemarks Radio-TLC (R f )0.45OK Radiochemical purity (%)Over 95%OK r-counter511 KeVOK pH6.5OK LAL Test-OK Microbiology TestNo growthOK

CONCLUSION We can enhance the efficiency of FDG module by optimizing of time, temperature and pressure in FDG production We enhanced the yield of FDG in 60±2.5%. For conveniences, we set up several accessories and demonstrated their advantage. As the results, these improvements lead to increasing FDG yields and handiness in using of domestic FDG module

Thanks for attention