ArticleNuclear medicine and biology2012
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).
Article in Nuclear medicine and biology, 2012. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 4 papers.
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4 citing papers in PubMed, 2 citations in OpenAlex.
- Comparison of the Hypoxia PET Tracer (18)F-EF5 to Immunohistochemical Marker EF5 in 3 Different Human Tumor Xenograft Models.Journal of nuclear medicine : official publication, Society of Nuclear Medicine · 2014Article
- Radiosynthesis of [18)F]trifluoroalkyl groups: scope and limitations.BioMed research international · 2014Review
- 18F-EF5 PET imaging as an early response biomarker for the hypoxia-activated prodrug SN30000 combined with radiation treatment in a non-small cell lung cancer xenograft model.Journal of nuclear medicine : official publication, Society of Nuclear Medicine · 2013Article
- 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).Nuclear medicine and biology · 2012Article
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4 authors at 2 institutions in 1 country.
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Abstract
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.
resultsThe 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.
conclusionA 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.
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