title: Photodynamic endometrial ablation in the nonhuman primate.
abstract: OBJECTIVE
  To test the effectiveness of 5-aminolevulinic acid (ALA)-induced photodynamic endometrial ablation in the rhesus monkey under varying conditions of light delivery (fractionated versus continuous) and steroid priming.
  
  
  METHODS
  Photodynamic endometrial ablation was carried out in 17 rhesus monkeys that were either postmenopausal or in the early proliferative phase. Four hours after intralumenal injection of ALA (250 mg in 1 mL hyskon), a quartz fiber with a diffusing tip was inserted. A KTP tunable dye laser delivered 300 mW of light (635 nm) for 60 minutes in either continuous or fractionated fashion (20 minutes on, 5 minutes off, and 40 minutes on). In some experiments, thermistors were used to monitor temperature in the lumen and myometrium during light treatment. Hysterectomy was performed 3 or 4 days after treatment, and endometrial damage was assessed histologically. Two additional monkeys (one rhesus and one cynomolgus monkey) were exposed to the same protocol, except hyskon was substituted for ALA to control for potential ablative effects due to light treatment alone.
  
  
  RESULTS
  Endometrial ablation was evident in all ALA-photosensitized specimens. The degree of ablation around the light fiber ranged from moderate to complete. The depth of ablation ranged from 1.14 +/- 0.54 to 2.15 +/- 1.62 mm (mean +/- standard deviation). Ablation was most complete in uteri of menopausal monkeys. Light treatment after ALA increased lumenal temperature from 36 C to 50 C, whereas temperature was not significantly increased by light treatment in the controls.
  
  
  CONCLUSIONS
  This is the first report of endometrial destruction in the primate using a photodynamic approach. Whereas clinical application of photodynamic therapy (PDT) requires complete endometrial ablation to produce long-lasting amenorrhea, our results suggest that PDT may offer a simple office-based approach to endometrial ablation.
authors.affiliation: Department of Obstetrics and Gynecology, Queen's University, Kingston, Ontario, Canada. vanvugtd@post.queensu.ca
authors.forename: D A
authors.initials: DA
authors.lastname: Van Vugt
authors.forename: A
authors.initials: A
authors.lastname: Krzemien
authors.forename: B N
authors.initials: BN
authors.lastname: Roy
authors.forename: W A
authors.initials: WA
authors.lastname: Fletcher
authors.forename: W
authors.initials: W
authors.lastname: Foster
authors.forename: S
authors.initials: S
authors.lastname: Lundahl
authors.forename: S L
authors.initials: SL
authors.lastname: Marcus
authors.forename: R L
authors.initials: RL
authors.lastname: Reid
mesh_terms: D000622:Aminolevulinic Acid / Q000627:therapeutic use*; D000818:Animals; D004717:Endometrium / Q000473:pathology*; D005260:Female; D008027:Light; D008253:Macaca mulatta; D008593:Menopause; D010778:Photochemotherapy; D013696:Temperature
chemical_list: D000622:Aminolevulinic Acid