title: 5-Aminolevulinic acid-induced protoporphyrin IX fluorescence in meningioma: qualitative and quantitative measurements in vivo.
abstract: BACKGROUND
  The use of 5-aminolevulinic acid (ALA)-induced protoporphyrin IX (PpIX) fluorescence has shown promise as a surgical adjunct for maximizing the extent of surgical resection in gliomas. To date, the clinical utility of 5-ALA in meningiomas is not fully understood, with most descriptive studies using qualitative approaches to 5-ALA-PpIX.
  
  
  OBJECTIVE
  To assess the diagnostic performance of 5-ALA-PpIX fluorescence during surgical resection of meningioma.
  
  
  METHODS
  ALA was administered to 15 patients with meningioma undergoing PpIX fluorescence-guided surgery at our institution. At various points during the procedure, the surgeon performed qualitative, visual assessments of fluorescence by using the surgical microscope, followed by a quantitative fluorescence measurement by using an intraoperative probe. Specimens were collected at each point for subsequent neuropathological analysis. Clustered data analysis of variance was used to ascertain a difference between groups, and receiver operating characteristic analyses were performed to assess diagnostic capabilities.
  
  
  RESULTS
  Red-pink fluorescence was observed in 80% (12/15) of patients, with visible fluorescence generally demonstrating a strong, homogenous character. Quantitative fluorescence measured diagnostically significant PpIX concentrations (cPpIx) in both visibly and nonvisibly fluorescent tissues, with significantly higher cPpIx in both visibly fluorescent (P < .001) and tumor tissue (P = .002). Receiver operating characteristic analyses also showed diagnostic accuracies up to 90% for differentiating tumor from normal dura.
  
  
  CONCLUSIONS
  ALA-induced PpIX fluorescence guidance is a potential and promising adjunct in accurately detecting neoplastic tissue during meningioma resective surgery. These results suggest a broader reach for PpIX as a biomarker for meningiomas than was previously noted in the literature.
authors.affiliation: *Section of Neurosurgery, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire; ‡Thayer School of Engineering, Hanover, New Hampshire; §Geisel School of Medicine at Dartmouth, Hanover, New Hampshire; ‖Departments of Pathology and Neurology, Georgetown University Medical Center, Washington, DC; ¶Ontario Cancer Institute, University of Toronto, Toronto, Ontario, Canada; #Engineering Physics Department, École Polytechnique de Montréal, Montreal, Quebec, Canada; **Norris Cotton Cancer Center, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire.
authors.forename: Pablo A
authors.initials: PA
authors.lastname: Valdes
authors.forename: Kimon
authors.initials: K
authors.lastname: Bekelis
authors.forename: Brent T
authors.initials: BT
authors.lastname: Harris
authors.forename: Brian C
authors.initials: BC
authors.lastname: Wilson
authors.forename: Frederic
authors.initials: F
authors.lastname: Leblond
authors.forename: Anthony
authors.initials: A
authors.lastname: Kim
authors.forename: Nathan E
authors.initials: NE
authors.lastname: Simmons
authors.forename: Kadir
authors.initials: K
authors.lastname: Erkmen
authors.forename: Keith D
authors.initials: KD
authors.lastname: Paulsen
authors.forename: David W
authors.initials: DW
authors.lastname: Roberts
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000622:Aminolevulinic Acid; D000704:Analysis of Variance; D016000:Cluster Analysis; D005260:Female; D005453:Fluorescence; D005456:Fluorescent Dyes; D006801:Humans; D008027:Light; D008297:Male; D008577:Meningeal Neoplasms / Q000175:diagnosis / Q000378:metabolism / Q000601:surgery*; D008579:Meningioma / Q000175:diagnosis / Q000378:metabolism / Q000601:surgery*; D008875:Middle Aged; D009367:Neoplasm Staging; D019635:Neurosurgical Procedures; D011446:Prospective Studies; D011524:Protoporphyrins / Q000378:metabolism*; D012372:ROC Curve; D012680:Sensitivity and Specificity
chemical_list: D005456:Fluorescent Dyes; D011524:Protoporphyrins; D000622:Aminolevulinic Acid; C028025:protoporphyrin IX