title: Studies on 18F-labeled pyrimidines. Tumor uptakes of 18F-5-fluorouracil, 18F-5-fluorouridine, and 18F-5-fluorodeoxyuridine in animals.
abstract: Three 18F-labeled pyrimidines, 18F-5-fluorouridine (18F-5-FUR), 18F-5-fluorouracil (18F-5-FU), and 18F-5-fluorodeoxyuridine (18F-5-FdUR), were examined regarding tissue distribution and tumor uptake in ascitic hepatoma AH109A-bearing rats. The differential absorption ratios of tumors of 18F-5-FUR, 18F-5-FU, and 18F-5-FdUR were 0.75 +/- 0.21, 0.92 +/- 0.15, and 0.96 +/- 0.24 at 30 min, and 0.37 +/- 0.09, 0.64 +/- 0.34, and 0.60 +/- 0.17 at 120 min, respectively. The tumor-to-organ ratios obtained with three radiopharmaceuticals, especially with blood, heart, lung, muscle, and brain were high and these ratios increased with time. The tumor-to-organ ratios obtained with 18F-5-FdUR were always 1.3-4 times higher than 18F-5-FU and 18F-5-FUR. We concluded that 18F-5-FdUR was a suitable radiopharmaceutical for tumor imaging. Positron emission tomography of a rabbit tumor located on the chest with 18F-5-FdUR clearly showed the tumor within 1 h.
mesh_terms: D000818:Animals; D001345:Autoradiography; D005467:Floxuridine / Q000378:metabolism*; D005461:Fluorine; D005472:Fluorouracil / Q000378:metabolism*; D008114:Liver Neoplasms, Experimental / Q000378:metabolism*; D008297:Male; D011868:Radioisotopes; D051381:Rats; D011919:Rats, Inbred Strains; D014018:Tissue Distribution; D014055:Tomography, Emission-Computed; D014529:Uridine / Q000031:analogs & derivatives* / Q000378:metabolism
chemical_list: D011868:Radioisotopes; D005467:Floxuridine; D005461:Fluorine; C001943:5-fluorouridine; D005472:Fluorouracil; D014529:Uridine