Fluorescence-guided surgery in high grade gliomas using an exoscope system.
BACKGROUND
Fluorescence-guided microsurgical resections of high-grade gliomas using 5-aminolevulinic acid (5-ALA) is superior to conventional microsurgery. An optical device, usually a modified microscope, is needed for these procedures. However, an exoscope may be implemented for fluorescence techniques. We present the use of an exoscope to perform tumor resection guided by 5-ALA fluorescence in 21 consecutive patients with high-grade glioma and two neuronavigation-guided biopsies.


METHODS
Twenty-three patients underwent operations. Tumor volume and localization were quantified with pre- and postoperative volumetric MRI in non-biopsy cases.


RESULTS
In non-biopsy cases, the age range was 20 to 79 years, with a median of 56 (interquartile range = 45-66). Histological analysis indicated that 14 had glioblastoma multiforme, 2 grade-III oligodendrogliomas and 1 anaplastic astrocytoma, 3 metastases and 1 low-grade astrocytoma. Total resection was achieved in 15 cases; subtotal resection was performed in 5 patients. The result was partial resection in one case. There was no perioperative mortality. The median fluorescence intensity, on a scale of 1-5, was 4.5 in the GBM group (IQR = 4-5), 3 (IQR = 2.5-3.5) in anaplastic glioma, and 2.5 (IQR = 2.25-2.75) for oligodendrogliomas. Of the three metastases, one showed fluorescence level 4. As for the two biopsy cases, one was anaplastic astrocytoma and one glioblastoma multiforme. The samples obtained were fluorescent in both cases.


CONCLUSIONS
An exoscope can be also used for fluorescence-guided surgery with 5-aminolevulinic acid (5-ALA) and neuronavigation-guided biopsy. With an important advantage of low cost, this allows the surgeon to perform collaborative surgeries and adds agility to the procedure.
Neurosurgery Service, Hospital de la Ribera, Carretera Corbera, 46600, Alzira, Valencia, Spain, jose.piquer@telefonica.net.
José Piquer
JP
Belloch
Vicente
V
Rovira
Jose L
JL
Llácer
Pedro A
PA
Riesgo
Antonio
A
Cremades
D000328:Adult; D000368:Aged; D000622:Aminolevulinic Acid; D001254:Astrocytoma / Q000473:pathology / Q000601:surgery; D001706:Biopsy; D001932:Brain Neoplasms / Q000473:pathology / Q000601:surgery*; D005260:Female; D005456:Fluorescent Dyes; D005909:Glioblastoma / Q000473:pathology / Q000601:surgery; D005910:Glioma / Q000473:pathology / Q000601:surgery*; D006801:Humans; D008297:Male; D008856:Microscopy, Fluorescence / Q000379:methods*; D008866:Microsurgery / Q000379:methods*; D008875:Middle Aged; D038361:Neuronavigation / Q000379:methods*; D009837:Oligodendroglioma / Q000473:pathology / Q000601:surgery; D012189:Retrospective Studies; D016896:Treatment Outcome
D005456:Fluorescent Dyes; D000622:Aminolevulinic Acid