title: Determining light dose for photodynamic therapy of atherosclerotic lesions in the Yucatan miniswine.
abstract: OBJECTIVE
  To determine the light dose required for photodynamic therapy of atherosclerotic lesions in the miniswine.
  
  
  METHODS
  Aortic atherosclerosis was created in seven Yucatan miniswine by a combination of balloon endothelial injury and 2% cholesterol and 15% lard for 7 weeks. Six animals received the photosensitizer Photofrin 2.5 mg/kg, while an additional swine received no drug. After 24 hours, the abdominal aorta was exposed and the aorta opened longitudinally in each animal. Three 1-cm spots were illuminated with energy densities of 60, 120, and 240 J/cm2 from an argon-pumped dye laser tuned to 630 nm with a laser output of 1 W. Four weeks later, the animals were killed, abdominal aortae removed, and intimal thickness determined by morphometry.
  
  
  RESULTS
  The percentage intimal thickness (mean +/- SD) was 36.7 +/- 27.1, 9.1 +/- 5.0, and 6.4 +/- 8.1 for the three energy densities, respectively. Although both 120 and 240 J/cm2 energy densities produced significant (p < 0.05) reduction in atheroma, considerable damage to the underlying media was also observed in the 240 J/cm2 group.
  
  
  CONCLUSIONS
  A Photofrin dose of 2.5 mg/kg and 120 J/cm2 light are necessary for adequate ablation of atheroma while avoiding extensive medial damage.
authors.affiliation: Department of Surgery, University of British Columbia, Vancouver, Canada.
authors.forename: Y N
authors.initials: YN
authors.lastname: Hsiang
authors.forename: M E
authors.initials: ME
authors.lastname: Todd
authors.forename: R D
authors.initials: RD
authors.lastname: Bower
mesh_terms: D000818:Animals; D001012:Aorta, Abdominal / Q000187:drug effects / Q000473:pathology / Q000528:radiation effects*; D001161:Arteriosclerosis / Q000188:drug therapy* / Q000473:pathology; D004307:Dose-Response Relationship, Radiation; D005260:Female; D005500:Follow-Up Studies; D007262:Infusions, Intravenous; D053685:Laser Therapy; D008297:Male; D010778:Photochemotherapy / Q000379:methods*; D017319:Photosensitizing Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D013552:Swine; D013556:Swine, Miniature
chemical_list: D017319:Photosensitizing Agents