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A simplified synthesis of the hypoxia imaging agent 2-(2-Nitro-1H-imidazol-1-yl)-N-(2,2,3,3,3-[(18)F]pentafluoropropyl)-acetamide ([18F]EF5).

Publication ,  Journal Article
Chitneni, SK; Bida, GT; Dewhirst, MW; Zalutsky, MR
Published in: Nucl Med Biol
October 2012

INTRODUCTION: [(18)F]EF5 is a validated marker for PET imaging of tumor hypoxia. It is prepared by reacting a trifluoroallyl precursor with carrier-added [(18)F]F(2) gas in trifluoroacetic acid (TFA) solvent. We report here an improved radiosynthesis and purification of [(18)F]EF5 by utilizing an electroformed nickel (Ni) target for [(18)F]F(2) production, and Oasis® HLB cartridges for on-line solid phase extraction of [(18)F]EF5 prior to HPLC purification. METHODS: [(18)F]F(2) was produced by deuteron bombardment of neon plus F(2) in an Ni target, and bubbled through the radiolabelling precursor solution. Purification was achieved by extracting the contents of the crude reaction mixture onto Oasis HLB cartridges, and subsequently eluted onto a semi-preparative HPLC column for further separation. Purified [(18)F]EF5 was evaluated in small animal PET studies using HCT116 tumor xenografts in nude mice. RESULTS: The electroformed Ni target enabled recovery of >75% of the radioactivity from the cyclotron target, resulting in 16.2 ± 2.2 GBq (438 ± 58 mCi) of [(18)F]F(2) available for the synthesis. Use of Oasis cartridges yielded a less complex mixture for purification. On average, 1140 ± 200 MBq (30.8 ± 5.4 mCi) of [(18)F]EF5 were collected at EOS. Small animal PET imaging studies showed specific retention of [(18)F]EF5 in tumors, with tumor-to-muscle ratios of 2.7 ± 0.3 at about 160 min after injection. CONCLUSION: A simple procedure has been developed for the routine synthesis of [(18)F]EF5 in amounts and purity required for clinical studies. This new method avoids the need for TFA evaporation and also enables facile automation of the synthesis using commercially available radiosynthesis modules.

Duke Scholars

Published In

Nucl Med Biol

DOI

EISSN

1872-9614

Publication Date

October 2012

Volume

39

Issue

7

Start / End Page

1012 / 1018

Location

United States

Related Subject Headings

  • Solid Phase Extraction
  • Radiochemistry
  • Positron-Emission Tomography
  • Nuclear Medicine & Medical Imaging
  • Mice, Nude
  • Mice
  • Hydrocarbons, Fluorinated
  • Humans
  • HCT116 Cells
  • Female
 

Citation

APA
Chicago
ICMJE
MLA
NLM
Chitneni, S. K., Bida, G. T., Dewhirst, M. W., & Zalutsky, M. R. (2012). A simplified synthesis of the hypoxia imaging agent 2-(2-Nitro-1H-imidazol-1-yl)-N-(2,2,3,3,3-[(18)F]pentafluoropropyl)-acetamide ([18F]EF5). Nucl Med Biol, 39(7), 1012–1018. https://doi.org/10.1016/j.nucmedbio.2012.05.006
Chitneni, Satish K., Gerald T. Bida, Mark W. Dewhirst, and Michael R. Zalutsky. “A simplified synthesis of the hypoxia imaging agent 2-(2-Nitro-1H-imidazol-1-yl)-N-(2,2,3,3,3-[(18)F]pentafluoropropyl)-acetamide ([18F]EF5).Nucl Med Biol 39, no. 7 (October 2012): 1012–18. https://doi.org/10.1016/j.nucmedbio.2012.05.006.
Chitneni, Satish K., et al. “A simplified synthesis of the hypoxia imaging agent 2-(2-Nitro-1H-imidazol-1-yl)-N-(2,2,3,3,3-[(18)F]pentafluoropropyl)-acetamide ([18F]EF5).Nucl Med Biol, vol. 39, no. 7, Oct. 2012, pp. 1012–18. Pubmed, doi:10.1016/j.nucmedbio.2012.05.006.
Journal cover image

Published In

Nucl Med Biol

DOI

EISSN

1872-9614

Publication Date

October 2012

Volume

39

Issue

7

Start / End Page

1012 / 1018

Location

United States

Related Subject Headings

  • Solid Phase Extraction
  • Radiochemistry
  • Positron-Emission Tomography
  • Nuclear Medicine & Medical Imaging
  • Mice, Nude
  • Mice
  • Hydrocarbons, Fluorinated
  • Humans
  • HCT116 Cells
  • Female