Dexamethasone-inhibited pertechnetate uptake in metastatic carcinoma of the cerebellum.

Two sodium pertechnetate Tc 99m brain scans, done within several days of each other, demonstrated inhibition of pertechnetate localization in a cerebellar lesion after dexamethasone therapy for cerebral edema. The lesion, a metastasis from a bronchogenic mucinous adenocarcinoma, was clearly present in the first scan, which was done before treatment.