title: Imaging of human colon cancer xenograft with gadolinium-texaphyrin.
abstract: OBJECTIVE
  The authors explore the efficacy of gadolinium (Gd)-texaphyrin (PCI-0101), an expanded porphyrin, as a contrast medium for magnetic resonance imaging of nude mice implanted with the human colon cancer xenograft LS174T.
  
  
  METHODS
  Magnetic resonance images were obtained in six nude mice 7 to 8 days after implantation of LS174T cells in dorsal subcutaneous tissues. Spin-echo T1-weighted images were obtained at baseline and at 5, 15, and 60 minutes after injection of 10 or 20 mumols/kg of Gd-texaphyrin. Delayed images were obtained at 24 and 48 hours after injection. Region-of-interest measurements were taken of the tumors and of enhancing tumor rims at all time points. Percent enhancement was calculated and compared among the various time points.
  
  
  RESULTS
  All tumors were enhanced after injection of Gd-texaphyrin. Heterogeneous patterns of enhancement were seen, with peak enhancement seen at the 15-minute time point; however, greater enhancement was seen at 48 hours than at 24 hours after Gd-texaphyrin intravenous injection.
  
  
  CONCLUSIONS
  Gadolinium-texaphyrin may prove to be a useful contrast medium for magnetic resonance imaging of tumors.
authors.affiliation: Pharmacyclics, Inc., Sunnyvale, California 94086, USA.
authors.forename: S W
authors.initials: SW
authors.lastname: Young
authors.forename: Q
authors.initials: Q
authors.lastname: Fan
mesh_terms: D000818:Animals; D003110:Colonic Neoplasms / Q000175:diagnosis*; D003287:Contrast Media; D004195:Disease Models, Animal; D005682:Gadolinium; D006801:Humans; D008279:Magnetic Resonance Imaging; D008665:Metalloporphyrins; D051379:Mice; D008819:Mice, Nude; D009368:Neoplasm Transplantation / Q000473:pathology; D012878:Skin Neoplasms / Q000175:diagnosis*; D014183:Transplantation, Heterologous / Q000473:pathology
chemical_list: D003287:Contrast Media; D008665:Metalloporphyrins; D005682:Gadolinium