F-18 Labeled benzimidazole derivatives as potential radiotracer for positron emission tomography (PET) tumor imaging

This article reported the synthesis and bioevaluation of two [F-18] labeled benzimidazole derivatives, 4-(5(2-[F-18] fluoro-4-nitrobenzamido)-1-methyl-1H-benzimidazol-2-yl) butanoic acid ([F-18] FNBMBBA, [F-18]a1) and 3-(2-fluoroethyl)-7-methyl-2-propyl-3H-benzimidazole-5-carboxylic acid ([F-18] FEMPBBA, [F-18]b1) for PET tumor imaging. The preparation [F-18] FEMPBBA was completed in 1 h with overall radiochemical yield of 50-60% (without decay corrected). Biodistribution assay in S180 tumor bearing mice of both compounds were carried out, and the results are both meaningful. [F-18] FEMPBBA which can be taken as a revision of [F-18] FNBMBBA got an excellent result, and has significant advantages in some aspects compared with L-[F-18] FET and [F-18]-FDG in the same animal model, especially in tumor/brain uptake ratio. The tumor/brain uptake ratio of [F-18] FEMPBBA gets to 4.81, 7.15, and 9.8 at 30 min, 60 min and 120 min, and is much higher than that of L-[F-18] FET (2.54, 2.92 and 2.95) and[F-18]-FDG (0.61, 1.02, 1.33) at the same time point. The tumor/muscle and tumor/blood uptake ratio of [F-18] FEM-PBBA is also higher than that of L-[F-18] FET at 30 min and 60 min. This result indicates compound [F-18] FEMPBBA is a promising radiotracer for PET tumor imaging. (C) 2010 Elsevier Ltd. All rights reserved.