Fluorescence image-guided resection of intracranial meningioma: an experimental in vivo study on nude mice

Introduction: The use of photodynamic agents in malignant cranial tumor surgery is quite common. For example five-aminolevulinic acid (5-ALA)-induced porphyrins in malignant gliomas are potent photo-sensitizers. Until today there is no comparable selective fluorescent substance available for meningiomas. Nevertheless, there is a demand for intraoperative fluorescent identification of e.g. invasive skull base meningiomas to increase radicality. This study was established to investigate fluorescent image-guided resection with somatostatin receptor labelled fluorescence dye for intracranial meningioma in the nude mice. Methods: Primary meningioma cell culture samples were stereotactically implanted subdural into 20 nude mice. 90 days after inoculation of the cells, a cranial MRI with contrast agent revealed tumor growth. After detection of tumor mass in MRI, FAM-TOC5,6-Carboxyfluoresceine-Tyr3-Octreotide was injected intravenously and tumor mass was hereafter resected under visualization via fluorescence microscope and endoscope. After attempted total resection, animal were sacrificed brain slices were obtained and histologically analysed to verify the resection extent. Results: In 18 mice tumor growth was detected in MRI after 90 days of inoculation. The tumor mass could be clearly identified with fluorescence microscope and endoscope after injecting FAM-TOC5,6-Carboxyfluoresceine-Tyr3-Octreotide. The tumor margins could be better visualized. After fluorescence-guided resection no remaining tumor could be identified in histological analysis. Conclusions: This study describes for the first time the use of FAM-TOC5,6-Carboxyfluoresceine-Tyr3-Octreotide and demonstrates its value of fluorescent identification of meningioma cells in vivo. Furthermore, the authors established a new experimental animal model for fluorescence meningioma surgery. (C) 2021 Published by Elsevier GmbH.

Automated summary

This study investigated fluorescent image-guided resection with somatostatin receptor labelled fluorescence dye for intracranial meningioma in nude mice, demonstrating the value of this method in clearly identifying tumor margins and promoting complete tumor resection. A new experimental animal model for fluorescence meningioma surgery was also established.