Synthesis, radiofluorination, and in vivo evaluation of novel fluorinated and iodinated radiotracers for PET imaging and targeted radionuclide therapy of melanoma

J Med Chem. 2013 Nov 14;56(21):8455-67. doi: 10.1021/jm400877v. Epub 2013 Oct 21.

Abstract

Our project deals with a multimodal approach using a single fluorinated and iodinated melanin-targeting structure and offering both imaging (positron emission tomography (PET)/fluorine-18) and treatment (targeted radionuclide therapy/iodine-131) of melanoma. Six 6-iodoquinoxaline-2-carboxamide derivatives with various side chains bearing fluorine were synthesized and radiofluorinated, and their in vivo biodistribution was studied by PET imaging in B16Bl6 primary melanoma-bearing mice. Among this series, [(18)F]8 emerged as the most promising compound. [(18)F]8 was obtained by a fully automated radiosynthesis process within 57 min with an overall radiochemical yield of 21%, decay-corrected. PET imaging of [(18)F]8 demonstrated very encouraging results as early as 1 h postinjection with high tumor uptake (14.33% ± 2.11% ID/g), high contrast (11.04 ± 2.87 tumor-to-muscle ratio), and favorable clearance properties. These results, associated with the previously reported pharmacokinetic properties and dosimetry of 8, make it a potential agent for both PET imaging and targeted radionuclide therapy of melanoma.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Disease Models, Animal
  • Melanoma, Experimental / diagnostic imaging*
  • Melanoma, Experimental / radiotherapy*
  • Mice
  • Mice, Inbred C57BL
  • Molecular Structure
  • Positron-Emission Tomography*
  • Quinoxalines / chemical synthesis
  • Quinoxalines / therapeutic use*
  • Radioactive Tracers*
  • Tissue Distribution
  • Tumor Cells, Cultured

Substances

  • N-(12-ethyl-1-fluoro-3,6,9-trioxa-12-azatetradecan-14-yl)-6-iodoquinoxaline-2-carboxamide
  • Quinoxalines
  • Radioactive Tracers