title: Biodistribution and PET imaging of [(18)F]-fluoroadenosine derivatives.
abstract: BACKGROUND
  Many fluorinated analogues of adenosine nucleoside have been synthesized and studied as potential antitumor and antiviral agents. Earlier, we reported radiosynthesis of 2'-deoxy-2'-[(18)F]fluoro-1-beta-D-arabinofuranosyl-adenine ([(18)F]-FAA) and 3'-deoxy-3'-[(18)F]fluoro-1-beta-d-xylofuranosyl-adenine ([(18)F]FXA). Now, we report their in vivo studies including blood clearance, biodistribution and micro-PET imaging in tumor-bearing nude mice.
  
  
  METHODS
  Tumors were grown in 6-week-old athymic nude mice (Harlan, Indianapolis, IN, USA) by inoculation of HT-29 cells, wild-type cells in the left flank and transduced cells with HSV-tk on the right flank. When the tumor was about 1 cm in size, animals were injected with these radiotracers for in vivo studies, including blood clearance, micro-PET imaging and biodistribution.
  
  
  RESULTS
  Uptake of [(18)F]FAA in tumor was 3.3-fold higher than blood, with highest uptake in the spleen. Maximum uptake of [(18)F]FXA was observed in the heart compared to other organs. There was no tumor uptake of [(18)F]FXA. Biodistribution results were supported by micro-PET images, which also showed very high uptake of [(18)F]FAA in spleen and visualization of tumors, and high uptake of [(18)F]FXA in the heart.
  
  
  CONCLUSIONS
  These results suggest that [(18)F]FAA may be useful for tumor imaging, while [(18)F]FXA may have potential as a heart imaging agent with PET.
authors: Department of Radiology, PET Imaging Science Center, University of Southern California, Los Angeles, CA 90033, USA. alauddin@di.mdacc.tmc.edu
authors: Mian M
authors: MM
authors: Alauddin
authors: Antranik
authors: A
authors: Shahinian
authors: Ryan
authors: R
authors: Park
authors: Michael
authors: M
authors: Tohme
authors: John D
authors: JD
authors: Fissekis
authors: Peter S
authors: PS
authors: Conti
mesh_terms: D000230:Adenocarcinoma / Q000000981:diagnostic imaging* / Q000378:metabolism*; D000241:Adenosine / Q000031:analogs & derivatives* / Q000493:pharmacokinetics; D000818:Animals; D019073:HT29 Cells; D006801:Humans; D008657:Metabolic Clearance Rate; D051379:Mice; D008819:Mice, Nude; D009928:Organ Specificity; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D014018:Tissue Distribution
chemical_list: D019275:Radiopharmaceuticals; C034064:2-fluoroadenosine; D000241:Adenosine