title: Sodium fluorescein-guided resection under the YELLOW 560 nm surgical microscope filter in malignant brain tumor surgery--a feasibility study.
abstract: OBJECTIVE
  In glioma surgery, the extent of resection (EOR) is one important predictor of progression-free survival. In 2006, fluorescence-guided surgery using 5-aminolevulinic acid (5-ALA) was shown to improve the EOR in malignant gliomas. However, the use of 5-ALA is complex and causes certain side effects. Sodium fluorescein (FL) is a fluorescent dye that is used for angiography in ophthalmic surgery. FL accumulates in areas of the disturbed blood-brain barrier and can be visualized under a 560-nm wavelength fluorescent light source (YELLOW 560 nm, Carl Zeiss Meditec, Oberkochen, Germany). Here, we present the first experiences with low-dose FL and YELLOW 560 nm in 35 patients with malignant brain tumors.
  
  
  METHODS
  A total of 200 mg of FL (3-4 mg/kg bodyweight) was administered in 35 patients during craniotomy as an off-label use between May and August 2012. We retrospectively analyzed the histology, pre-treatment, clinical parameters pre- and postoperatively and occurrence of any adverse effects. The feasibility and efficacy ('helpful,' 'not helpful') of FL under YELLOW 560 nm (demarcation of the tumor margin) was assessed by the responsible neurosurgeon (n = 5) for each surgical procedure.
  
  
  RESULTS
  Twenty-six patients had gliomas (1 WHO grade I, 3 WHO grade II, 5 WHO grade III, 17 WHO grade IV), 5 patients had cerebral metastases, 2 had non-malignant astrogliosis and 2 had post-radiation necrosis. The fluorescence signal was detected in all patients immediately after the FL administration. FL application was classified as 'helpful' in 28 patients, implying improved visualization of the tumor margins. The intensity of the fluorescence signal seemed to be correlated to the histology and was strongly dependent on the pre-treatment status. We did not record any allergic reactions or any other adverse effects.
  
  
  CONCLUSIONS
  The use of FL for the resection of brain tumors is safe and feasible. Presumably, the visualization of the tumor margin depends on the histopathology and on the pre-treatment status. A randomized evaluation of FL under the YELLOW 560 nm filter is planned to prospectively analyze the extent of resection in patients with malignant brain tumors.
authors: Department of Neurosurgery, University Hospital of Regensburg, Franz-Josef-Strauss Allee 11, 93053, Regensburg, Germany. karl-michael.schebesch@klinik.uni-regensburg.de
authors: Karl-Michael
authors: KM
authors: Schebesch
authors: Martin
authors: M
authors: Proescholdt
authors: Julius
authors: J
authors: Höhne
authors: Christoph
authors: C
authors: Hohenberger
authors: Ernil
authors: E
authors: Hansen
authors: Markus J
authors: MJ
authors: Riemenschneider
authors: Winfried
authors: W
authors: Ullrich
authors: Christian
authors: C
authors: Doenitz
authors: Juergen
authors: J
authors: Schlaier
authors: Max
authors: M
authors: Lange
authors: Alexander
authors: A
authors: Brawanski
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001932:Brain Neoplasms / Q000473:pathology / Q000601:surgery*; D005240:Feasibility Studies; D005260:Female; D019793:Fluorescein; D005456:Fluorescent Dyes; D005910:Glioma / Q000473:pathology / Q000601:surgery*; D006801:Humans; D008297:Male; D008856:Microscopy, Fluorescence / Q000379:methods*; D008875:Middle Aged; D019635:Neurosurgical Procedures / Q000379:methods*; D055815:Young Adult
chemical_list: D005456:Fluorescent Dyes; D019793:Fluorescein