Intraoperative confocal microscopy for brain tumors: a feasibility analysis in humans

Neurosurgery. 2011 Jun;68(2 Suppl Operative):282-90; discussion 290. doi: 10.1227/NEU.0b013e318212464e.


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.

Conclusion: 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.

MeSH terms

  • Adult
  • Aged
  • Biopsy
  • Brain Neoplasms / pathology*
  • Brain Neoplasms / surgery
  • Feasibility Studies
  • Female
  • Glioma / pathology
  • Glioma / surgery
  • Humans
  • Image Processing, Computer-Assisted
  • Intraoperative Period
  • Male
  • Meningeal Neoplasms / pathology
  • Meningeal Neoplasms / surgery
  • Meningioma / pathology
  • Meningioma / surgery
  • Microscopy, Confocal / methods*
  • Middle Aged
  • Neoplasm Grading
  • Neoplasm Metastasis