Intra-operative characterization of gliomas by near-infrared spectroscopy: possible association with prognosis

Growth and expansion of gliomas are highly dependent on vascular neogenesis. An association of microvascular density and tumour energy metabolism is assumed in most human gliomas. The purpose of this investigation was to characterize a series of gliomas by intra-operative near-infrared spectroscopy (NIRS), and to elucidate the relationship between microvascular blood volume (BV), oxygen saturation (SaO(2)), histology and patient survival. The study included 13 patients with gliomas, in whom complete tumour resection according to postoperative magnetic resonance imaging criteria was achieved. Intra-operatively, one low grade astrocytoma, five anaplastic astrocytomas and seven glioblastomas with the ipsilateral cortex were investigated by NIRS revealing capillary BV (total haemoglobin) and SaO(2). Intratumoural BV (tBV) and SaO(2) (tSaO(2)) were additionally used in relation to histology and survival. The mean tBV of the astrocytomas was 4.96 mg/ml compared to 18.40 mg/ml in the glioblastoma group. Mean tSaO(2) was 36% in the astrocytoma group and 52% in the glioblastomas, respectively. Both tBV and tSaO(2) were significantly higher (p10/mg/ml (10 months), and tSaO(2) >50% (10 months). Longest median survival times were observed in the astrocytoma group (32.5 months), in patients with Tbv