gms | German Medical Science

Objective: Five-aminolevulinic acid (5-ALA) staining of malignant glioma cells increases radicality. Until today there is no comparable fluorescent substance available for meningioma cells. Nevertheless, there is a demand for intraoperative fluorescent identification of e.g. invasive skull base meningiomas to increase radicality.

Meningiomas show high expression of the somatostatin receptor subtype 2 offering the possibility of receptor-targeted imaging. We used a somatostatin receptor labeled dye for identification of meningiomas in cell culture. The aim was to evaluate the possibility to identify meningioma cells with fluorescent techniques.

Methods: We investigated 22 primary human meningioma cell cultures. The tumor cells were incubated with FAM-TOC, 5,6-Carboxyfluoresceine-Tyr3-Octreotide. As a negative control, human dura was cultured in vitro and incubated with the same somatostatin receptor labeled fluorescence substance as negative control. After fixation and Dapi staining the cultures were analysed. We used an Olympus fluorescence microscope with 488nm epi-illumination.

Results: We analysed 14 WHO I cell cultures, six WHO II and two WHO III cell cultures. Also, two fibroblastic cell cultures from human dura tissue were analysed as well.

Fluorescence were detected in all meningioma cells. There was no difference of quality or quantity of fluorescence between the different meningioma grades. In the negative control, dura cells remained unstained.

Conclusion: It could be demonstrated that FAM-TOC, 5,6-Carboxyfluoresceine-Tyr3-Octreotide can be used for selective fluorescent identification of meningioma cells in cell culture. Further studies in vivo in animal models are necessary to analyse the potential of somatostatin receptor-targeted imaging in meningioma surgery.