Evaluation of 2′-deoxy-2′-[18F]fluoro-5-methyl-1-β-l-arabinofuranosyluracil ([18F]-l-FMAU) as a PET imaging agent for cellular proliferation: comparison with [18F]-d-FMAU and [18F]FLT

Purpose Clevudine (l-FMAU) an un-natural analogue of thymidine, is in clinical trials for the treatment of hepatitis B virus (HBV). l-FMAU is phosphorylated by cellular kinases such as thymidine kinase 1 and deoxycytidine kinase, and its triphosphate form inhibits HBV deoxyribonucleic acid synthesis. Thus, l-FMAU, radiolabeled with an appropriate isotope, may be useful for positron emission tomography (PET) imaging of tumor proliferation. We evaluated [18F]-l-FMAU as a PET imaging agent in tumor-bearing mice and compared the results with those of two other radiotracers, [18F]-d-FMAU and [18F]-FLT.