title: Optimization of automated large-scale production of [(18)F]fluoroethylcholine for PET prostate cancer imaging.
abstract: BACKGROUND
  PET tumor imaging is gaining importance in current clinical practice. FDG-PET is the most utilized approach but suffers from inflammation influences and is not utilizable in prostate cancer detection. Recently, (11)C-choline analogues have been employed successfully in this field of imaging, leading to a growing interest in the utilization of (18)F-labeled analogues: [(18)F]fluoroethylcholine (FEC) has been demonstrated to be promising, especially in prostate cancer imaging. In this work we report an automatic radiosynthesis of this tracer with high yields, short synthesis time and ease of performance, potentially utilizable in routine production sites.
  
  
  METHODS
  We used a Modular Lab system to automatically perform the two-step/one-pot synthesis. In the first step, we labeled ethyleneglycolditosylate obtaining [(18)F]fluoroethyltosylate; in the second step, we performed the coupling of the latter intermediate with neat dimethylethanolamine. The final mixture was purified by means of solid phase extraction; in particular, the product was trapped into a cation-exchange resin and eluted with isotonic saline.
  
  
  RESULTS
  The optimized procedure resulted in a non decay corrected yield of 36% and produced a range of 30-45 GBq of product already in injectable form. The product was analyzed for quality control and resulted as pure and sterile; in addition, residual solvents were under the required threshold.
  
  
  CONCLUSIONS
  In this work, we present an automatic FEC radiosynthesis that has been optimized for routine production. This findings should foster the interest for a wider utilization of this radiomolecule for imaging of prostate cancer with PET, a field for which no gold-standard tracer has yet been validated.
authors.affiliation: University of Pisa, Italy. giancarlo.pascali@bioclinica.unipi.it
authors.forename: Giancarlo
authors.initials: G
authors.lastname: Pascali
authors.forename: Luca
authors.initials: L
authors.lastname: D'Antonio
authors.forename: Paola
authors.initials: P
authors.lastname: Bovone
authors.forename: Paolo
authors.initials: P
authors.lastname: Gerundini
authors.forename: Thorsten
authors.initials: T
authors.lastname: August
mesh_terms: D001331:Automation; D002794:Choline / Q000031:analogs & derivatives* / Q000138:chemical synthesis; D002851:Chromatography, High Pressure Liquid; D006801:Humans; D008297:Male; D049268:Positron-Emission Tomography; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging*; D011786:Quality Control; D011851:Radioactivity
chemical_list: C448902:fluoroethylcholine; D002794:Choline