Serial computed tomography of primary brain tumors following surgery, irradiation, and chemotherapy

55 patients with primary brain tumors were studied by CT scans before, during, and after treatment to determine chronological changes in morphology. Pretreatment scans showed decreased density in most glioblastomas and low-grade astrocytomas and normal density in most unbiopsied tumors and optic nerve gliomas. All glioblastomas and 40% of the astrocytomas were enhanced by contrast material, suggesting that the latter tumor can be divided into two prognostic categories based on the presence or absence of enhancement. Lesion size regressed after treatment in 62% of patients, stabilized in 29%, and progressed in 9%. CT findings correlated with the clinical course in 93% of cases. 73% of tumors persisted, 20% disappeared, and 7% recurred after a mean follow-up of 10.1 months.