title: Syntheses of 18F-labeled pyrimidines and their usefulness for tumor imaging.
abstract: 18F-Labeled 5-fluorouracil(FUra), 5-fluoro-2'-deoxyuridine(FdUrd) and 5-fluorouridine(FUrd) were synthesized with high radiochemical purities. Biodistribution of the 18F-pyrimidines in tumor-bearing rats, mice or a rabbit was examined. Blood clearance of the 18F-pyrimidines was very rapid. The kidney and liver showed the high uptake and rapid clearance which was due to the metabolism and excretion. The 18F-concentration in the tumor was due to the metabolism and excretion. The 18F-concentration in the tumor was also high and clearance was very slow compared with those in other organs. Tumor uptakes of 18F-FdUrd were also shown by positron emission tomography and autoradiography. Biodistributions of the 18F-FdUrd and radio-deoxythymidine(dThd) were different between several organs, but similar distribution patterns in the tumor were observed by autoradiography.
mesh_terms: D000818:Animals; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D005467:Floxuridine / Q000138:chemical synthesis*; D005461:Fluorine; D005472:Fluorouracil / Q000138:chemical synthesis*; D005910:Glioma / Q000000981:diagnostic imaging*; D008114:Liver Neoplasms, Experimental / Q000000981:diagnostic imaging*; D008325:Mammary Neoplasms, Experimental / Q000000981:diagnostic imaging*; D051379:Mice; D011865:Radioisotope Dilution Technique; D011868:Radioisotopes; D011877:Radionuclide Imaging; D051381:Rats; D014529:Uridine / Q000031:analogs & derivatives* / Q000138:chemical synthesis
chemical_list: D011868:Radioisotopes; D005467:Floxuridine; D005461:Fluorine; C001943:5-fluorouridine; D005472:Fluorouracil; D014529:Uridine