Intraoperative measurement of peritumoral regional cortical cerebral blood flow

Peritumoral regional cortical blood flow (rCoBF) was studied intraoperatively using thermal diffusion flowmetry. Histology included glioblastomas (n=5), anaplastic astrocytoma (n=1), pilocytic astrocytomas (n=2), metastatic melanoma (n=1), and trigeminal schwannoma (n=1). Pre-resection rCoBF values were low in all but two tumors where perfusion was in the low normal range. Post-resection rCoBF values were either low or normalized. Seizure activity was documented in a pilocytic astrocytoma with a significant rCoBF increase during resection. Our findings indicate that hypoperfusion in the cortex adjacent to malignant brain tumors is the result of primary metabolic failure and tumor pressure ischemia.