Diagnosis of intracranial space-occupying lesions with DTPA-Sn-99mTc.

DTPA-Sn-99 mTc is an excellent radionuclide for brain scintigraphy procedures with a rapid blood clearance through glomerular filatration. No previous preparation of the patient is necessary. We have studied forty nine patients with primary or metastatic brain tumours as well as calvarium metastases. There have been five false negatives. We have found three types of scintigraphic patterns depending on whether the lesion is better visualized in early or late images, or does not change throughout the study. The sequential brain study, obtaining views at five minutes, and at one and two hours post-injection allows for an adequate morphological characterization of the lesion and occasionally, a histological diagnosis.