Computed Tomographic Features of Cerebral Malignant Glioma following Treatment and Regrowth: Growth Patterns of Recurrent Tumors

Patterns of growth and extension of recurrent cerebral anaplastic gliomas (glioblastomas) were studied by computed tomography (CT) in 48 patients. In 34 cases the original tumor was subcortical and in 14 cases it was deep-seated. All of the patients underwent surgical removal of the original tumor followed by radiation therapy and chemotherapy. Follow-up CT scans were obtained at intervals of 1.0±0.6 months. Only contrast enhanced (CE) lesions were regarded as recurrent tumors. Four patterns of tumor growth and extension were observed: extension to subcortical white matter (38 cases, 79%); extension along the periventricular region (40 cases, 83%); extension toward the basal ganglia (21 cases, 44%); and metastasis via cerebrospinal fluid to the brain surface and posterior fossa (10 cases, 21%). Every patient exhibited one or more of these patterns during follow-up. In the subcortical tumor group, CE lesions extended step-wise to the ipsilateral periventricular region, corpus callosum, contralateral periventricular region, and entire ventricles at 0.5±1.5, 2.7±3.1, 4.0±3.8, and 6.1±2.9 months, respectively, after recurrence was first detected, and death occurred after the subsequent 1.8±2.0 months. Similar step-wise growth patterns were also observed in the deep-seated tumor group, but the tumor sites were so varied that it was difficult to draw prognostic conclusions for this group.