title: Combining 5-Aminolevulinic Acid Fluorescence and Intraoperative Magnetic Resonance Imaging in Glioblastoma Surgery: A Histology-Based Evaluation.
abstract: BACKGROUND
  Glioblastoma resection guided by 5-aminolevulinic acid (5-ALA) fluorescence and intraoperative magnetic resonance imaging (iMRI) may improve surgical results and prolong survival.
  
  
  OBJECTIVE
  To evaluate 5-ALA fluorescence combined with subsequent low-field iMRI for resection control in glioblastoma surgery.
  
  
  METHODS
  Fourteen patients with suspected glioblastoma suitable for complete resection of contrast-enhancing portions were enrolled. The surgery was carried out using 5-ALA-induced fluorescence and frameless navigation. Areas suspicious for tumor underwent biopsy. After complete resection of fluorescent tissue, low-field iMRI was performed. Areas suspicious for tumor remnant underwent biopsy under navigation guidance and were resected. The histological analysis was blinded.
  
  
  RESULTS
  In 13 of 14 cases, the diagnosis was glioblastoma multiforme. One lymphoma and 1 case without fluorescence were excluded. In 11 of 12 operations, residual contrast enhancement on iMRI was found after complete resection of 5-ALA fluorescent tissue. In 1 case, the iMRI enhancement was in an eloquent area and did not undergo a biopsy. The 28 biopsies of areas suspicious for tumor on iMRI in the remaining 10 cases showed tumor in 39.3%, infiltration zone in 25%, reactive central nervous system tissue in 32.1%, and normal brain in 3.6%. Ninety-three fluorescent and 24 non-fluorescent tissue samples collected before iMRI contained tumor in 95.7% and 87.5%, respectively.
  
  
  CONCLUSIONS
  5-ALA fluorescence-guided resection may leave some glioblastoma tissue undetected. MRI might detect areas suspicious for tumor even after complete resection of all fluorescent tissue; however, due to the limited accuracy of iMRI in predicting tumor remnant (64.3%), resection of this tissue has to be considered with caution in eloquent regions.
authors.affiliation: ‡Department of Neurosurgery, University Hospital, Zurich, Switzerland;§Department of Neurosurgery, Hirslanden Hospital, Zurich, Switzerland.
authors.forename: Sonja B
authors.initials: SB
authors.lastname: Hauser
authors.forename: Ralf A
authors.initials: RA
authors.lastname: Kockro
authors.forename: Bertrand
authors.initials: B
authors.lastname: Actor
authors.forename: Johannes
authors.initials: J
authors.lastname: Sarnthein
authors.forename: René-Ludwig
authors.initials: RL
authors.lastname: Bernays
mesh_terms: D000328:Adult; D000368:Aged; D000622:Aminolevulinic Acid / Q000737:chemistry*; D001706:Biopsy; D001932:Brain Neoplasms / Q000473:pathology / Q000601:surgery*; D005260:Female; D005453:Fluorescence; D005909:Glioblastoma / Q000473:pathology / Q000601:surgery*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D038361:Neuronavigation; D019635:Neurosurgical Procedures / Q000379:methods*; D025321:Surgery, Computer-Assisted / Q000379:methods*; D016019:Survival Analysis; D016896:Treatment Outcome
chemical_list: D000622:Aminolevulinic Acid