Combination technique with 67Ga-citrate and sup(99m)TcO4 in the brain scintigraphy by the conventional rectilinear scanner

sup(99m)TcO4 has been used most widely as a brain scan agent. In some instances however, sup(99m)Tc fails to demonstrate lesions which can be diagnosed with other radiopharmaceuticals. In order to compare the merits of 67Ga and sup(99m)Tc, the authors used both agents for brain scanning in each of 25 patients who were randomly selected to participate in the study. Of the 25 cases 22 were histologically proven cases: 2 with brain abscesses (one of them associated with ventriculities), 8 with metastatic carcinoma, 4 with meningioma, 1 with meningosarcoma, 2 with acoustic neurinoma, and one case each of pituitary chromophobe adenoma, astrocytoma, oligodendroglioma, glioma and meningitis. Three cases, which were not verified histologically, were observed for up to one year following the initial study with no findings of aggravated central nervous pathology. Pragmatically Tc remains the agent for routine screening. When it was difficult to interpret a scan with sup(99m)Tc, the attributes of 67Ga appeared to justify the additional effort, especially in the cases of meningioma, metastatic lesions and abscess. As reported before, 67Ga is the scan of first choice for malignant lymphomas and postoperative assessment of brain tumors. (Evans, J.)