ANGIOGENESIS AND BRAIN EDEMA IN INTRACRANIAL MENINGIOMAS - INFLUENCE OF VASCULAR ENDOTHELIAL GROWTH-FACTOR

The correlation between angiographic neovascularization, peritumoural brain oedema (PTBOe) and the expression of vascular endothelial growth factor (VEGF), was analysed in 30 patients with intracranial meningio mas. Pre-operative angiograms were examined for the existence of eithe r an exclusively dural tumour blush or an additionally pial tumour sup ply from cerebral arteries. Furthermore the presence of macroscopic tu mour-neovascularization and dysplastic changes of tumour-draining cere bral veins was evaluated. VEGF expression was investigated on histolog ical tissue samples, using immunohistochemical techniques. VEGF immuno histochemistry and neuroradiological evaluations were performed in dou ble blind fashion. Tumour volume and the amount of oedema were calcula ted by computerized tomography (CT) or magnetic resonance imaging (MRI ). The oedema-tumour volume ratio was defined as oedema index (OeI). C ompared to VEGF-negative meningiomas, rumours with striking VEGF stain ing revealed a significant higher mean oedema index (OeI = 4, 2 vs. Oe I = 1, 5; p < 0.018), and a higher oedema incidence (91,7% vs. 44,4%; p < 0.046). Equally, meningjomas with additionally tumour supply from cerebral arteries were associated with a significant higher mean OeI ( OeI = 4.1 vs. OeI = 1.2, p < 0.01) and oedema incidence (94,7% vs. 20, 0%; p < 0,0023) than meningiomas with exclusively tumour supply from d ural arteries. All meningiomas with striking VEGF-expression were asso ciated with Vascular tumour supply from cerebral arteries, but VEGF-ne gative tumours only in 50% (p < 0.029). These data suggest a link betw een VEGF-expression, arterial tumour supply and peritumoural brain oed ema. The development of tumour supply from cerebral arteries may be im portant for formation of meningioma-related oedema. Therefore, VEGF ma y represent a potent mediator in the evolution of this type of vascula rization in meningiomas.