title: Influence of the menstrual cycle on aminolevulinic acid induced protoporphyrin IX fluorescence in the endometrium: in vivo study.
abstract: OBJECTIVE
  In vitro studies indicated that compared to postmenopausal women, premenopausal women had increased aminolevulinic acid induced protoporphyrin IX (ALA-induced PpIX) fluorescence expression in the endometrium. The aim of this study was to evaluate menstrual cycle dependency of ALA-induced PpIX fluorescence in the endometrium in vivo.
  
  
  METHODS
  Thirteen patients were included for in vivo spectrofluorometric measurements of ALA-induced PpIX in the endometrium and 51 patients for fluorescence hysteroscopy. Two milliliter of a 2% 5-ALA-solution at pH = 4.0 (ASAT AG/Zug, Switzerland) was topically administrated just before spectrofluorometry and 4 hours before hysteroscopy. Spectrofluorometry: Optical fiber based. Fluorescence hysteroscopy: STORZ-D-Light system (Storz, Tuttlingen, Germany). Histological classification of curettage and bioptic endometrial tissue stained with hematoxylin and eosin (H&E).
  
  
  RESULTS
  Hysteroscopic and in vivo spectrofluorometric measurements showed an increase of ALA-induced PpIX fluorescence in the secretory and hyperplastic endometrium compared to proliferative and atrophic endometrium.
  
  
  CONCLUSIONS
  The accuracy of fluorescence hysteroscopy and the success of the photodynamic endometrial ablation using ALA-induced PpIX may depend on the hormonal influence of the menstrual cycle. The mechanisms responsible for the increased ALA-induced PpIX fluorescence in the secretory versus proliferative phase of the menstrual cycle deserve further studies.
authors.affiliation: Department of Obstetrics and Gynecology, University Hospital of Zurich, 8091 Zurich, Switzerland.
authors.forename: Andrea
authors.initials: A
authors.lastname: Degen
authors.forename: Tanja
authors.initials: T
authors.lastname: Gabrecht
authors.forename: Georges
authors.initials: G
authors.lastname: Wagnières
authors.forename: Rosmarie
authors.initials: R
authors.lastname: Caduff
authors.forename: Bruno
authors.initials: B
authors.lastname: Imthurn
authors.forename: Pius
authors.initials: P
authors.lastname: Wyss
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000622:Aminolevulinic Acid / Q000493:pharmacokinetics*; D001284:Atrophy; D004714:Endometrial Hyperplasia / Q000378:metabolism; D004717:Endometrium / Q000378:metabolism* / Q000473:pathology; D005260:Female; D005453:Fluorescence; D006801:Humans; D015907:Hysteroscopy / Q000379:methods; D008597:Menstrual Cycle; D008875:Middle Aged; D017319:Photosensitizing Agents / Q000493:pharmacokinetics*; D011524:Protoporphyrins / Q000493:pharmacokinetics*; D013050:Spectrometry, Fluorescence
chemical_list: D017319:Photosensitizing Agents; D011524:Protoporphyrins; D000622:Aminolevulinic Acid