Effect of dexamethasone treatment on volume and contrast enhancement of intracranial neoplasms.

In a prospective study the effect of dexamethasone treatment on tumor volume and contrast enhancement was evaluated by computed tomography (CT) in 15 patients with intracranial lesions. Histological diagnoses were confirmed in 13 patients who had undergone surgical intervention. A CT study of the head, with and without contrast medium, was performed prior to the dexamethasone treatment and at various intervals during the treatment for 8-19 days. The volume, attenuation, and contrast enhancement of the tumor were measured and related to the time after the start of the treatment. In six meningiomas there was no change in the volume and enhancement of the tumors. Out of four gliomas, there was an increase in volume of two tumors, whereas the other two cases showed a decrease in the tumor volume. In one glioma a distinct decrease in enhancement was observed. In three cases of metastasis a decrease in enhancement and tumor volume was noted. An acoustic neurinoma and an unverified lesion, considered radiologically to be a glioma, also showed a decrease in tumor volume and contrast enhancement. In tumors that responded to the treatment, a decrease both in volume of the tumor and peritumoral brain edema as well as a decrease in contrast enhancement of the tumor were observed.