Local cerebral blood flow and partition coefficients measured in cerebral astrocytomas of different grades of malignancy.

Local cerebral blood flow and local partition coefficients were measured in patients with different grades of malignant cerebral astrocytomas (n = 5) who inhaled 35% stable xenon during computed tomography scanning. Results were compared with those in age-matched normal subjects (n = 5. Mean values for local cerebral blood flow in the gray matter in patients with astrocytomas were decreased throughout the tumor mass and surrounding brain that was apparently free of tumor. Patients with highly malignant glioblastoma multiforme (astrocytoma grade IV; n = 2) showed more variable values for local cerebral blood flow and local partition coefficients compared to those with astrocytomas of lower grades (grades I-II; n = 3). Local partition coefficients in gray matter invaded by grade IV astrocytoma were significantly higher than those in gray matter invaded by grade I-III astrocytomas. Local cerebral blood flow and local partition coefficients in the brain tissue surrounding grade IV astrocytomas were reduced to a greater extent than those in more benign tumors.