title: Intraoperative confocal microscopy for brain tumors: a feasibility analysis in humans.
abstract: BACKGROUND
  The ability to diagnose brain tumors intraoperatively and identify tumor margins during resection could maximize resection and minimize morbidity. Advances in optical imaging enabled production of a handheld intraoperative confocal microscope.
  
  
  OBJECTIVE
  To present a feasibility analysis of the intraoperative confocal microscope for brain tumor resection.
  
  
  METHODS
  Thirty-three patients with brain tumor treated at Barrow Neurological Institute were examined. All patients received an intravenous bolus of sodium fluorescein before confocal imaging with the Optiscan FIVE 1 system probe. Optical biopsies were obtained within each tumor and along the tumor-brain interfaces. Corresponding pathologic specimens were then excised and processed. These data was compared by a neuropathologist to identify the concordance for tumor histology, grade, and margins.
  
  
  RESULTS
  Thirty-one of 33 lesions were tumors (93.9%) and 2 cases were identified as radiation necrosis (6.1%). Of the former, 25 (80.6%) were intra-axial and 6 (19.4%) were extra-axial. Intra-axial tumors were most commonly gliomas and metastases, while all extra-axial tumors were meningiomas. Among high-grade gliomas, vascular neoproliferation, as well as tumor margins, were identifiable using confocal imaging. Meningothelial and fibrous meningiomas were distinct on confocal microscopy--the latter featured spindle-shaped cells distinguishable from adjacent parenchyma. Other tumor histologies correlated well with standard neuropathology tissue preparations.
  
  
  CONCLUSIONS
  Intraoperative confocal microscopy is a practicable technology for the resection of human brain tumors. Preliminary analysis demonstrates reliability for a variety of lesions in identifying tumor cells and the tumor-brain interface. Further refinement of this technology depends upon the approval of tumor-specific fluorescent contrast agents for human use.
authors.affiliation: Department of Neurological Surgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, 350 West Thomas Road, Phoenix, AZ 85013, USA.
authors.forename: Nader
authors.initials: N
authors.lastname: Sanai
authors.forename: Jennifer
authors.initials: J
authors.lastname: Eschbacher
authors.forename: Guido
authors.initials: G
authors.lastname: Hattendorf
authors.forename: Stephen W
authors.initials: SW
authors.lastname: Coons
authors.forename: Mark C
authors.initials: MC
authors.lastname: Preul
authors.forename: Kris A
authors.initials: KA
authors.lastname: Smith
authors.forename: Peter
authors.initials: P
authors.lastname: Nakaji
authors.forename: Robert F
authors.initials: RF
authors.lastname: Spetzler
mesh_terms: D000328:Adult; D000368:Aged; D001706:Biopsy; D001932:Brain Neoplasms / Q000473:pathology* / Q000601:surgery; D005240:Feasibility Studies; D005260:Female; D005910:Glioma / Q000473:pathology / Q000601:surgery; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007432:Intraoperative Period; D008297:Male; D008577:Meningeal Neoplasms / Q000473:pathology / Q000601:surgery; D008579:Meningioma / Q000473:pathology / Q000601:surgery; D018613:Microscopy, Confocal / Q000379:methods*; D008875:Middle Aged; D060787:Neoplasm Grading; D009362:Neoplasm Metastasis