title: Intracranial mass lesions: sequential thallium and gallium scintigraphy in patients with AIDS.
abstract: OBJECTIVE
  To determine the efficacy of sequential thallium and gallium scintigraphy to differentiate intracranial neoplasms (lymphoma and glioma) from other nonmalignant intracranial mass lesions among patients with acquired immunodeficiency syndrome (AIDS).
  
  
  METHODS
  The authors reviewed the cases of 40 patients with human immunodeficiency virus (HIV) who underwent thallium and gallium scanning to evaluate intracranial mass lesions from October 1991 through November 1997. There was a definitive final diagnosis of the nature of the mass lesions in 21 of these cases. In these 21 cases, the scintigraphic patterns were reviewed and were compared with the final diagnosis.
  
  
  RESULTS
  On the basis of results at thallium and gallium scanning, the patients were divided into three groups. Group A included 13 patients (11 with brain tumors [lymphomas and gliomas] and two with progressive multifocal leukoencephalopathy [PML]) with thallium-positive, gallium-positive scans. Group B included five patients with intracranial infections (tuberculosis, Cryptococcus, bacteria) with thallium-negative, gallium-positive scans. Group C included three patients (one with PML and two with infarcts) with thallium-negative, gallium-negative scans. All patients with lymphomas were in group A. The sensitivity and specificity of the thallium-positive, gallium-positive pattern for intracranial malignancy were 100% and 80%, respectively.
  
  
  CONCLUSIONS
  Sequential thallium and gallium scanning helped differentiate tumors from nonmalignant intracranial mass lesions and may help differentiate infections from PML or infarcts.
authors.affiliation: Department of Radiology, Boston University School of Medicine, Boston Medical Center, MA 02118, USA.
authors.forename: V W
authors.initials: VW
authors.lastname: Lee
authors.forename: V
authors.initials: V
authors.lastname: Antonacci
authors.forename: S
authors.initials: S
authors.lastname: Tilak
authors.forename: J D
authors.initials: JD
authors.lastname: Fuller
authors.forename: T P
authors.initials: TP
authors.lastname: Cooley
mesh_terms: D000163:Acquired Immunodeficiency Syndrome / Q000150:complications*; D000328:Adult; D000368:Aged; D001927:Brain Diseases / Q000150:complications / Q000000981:diagnostic imaging*; D001932:Brain Neoplasms / Q000150:complications / Q000000981:diagnostic imaging*; D005260:Female; D005710:Gallium Radioisotopes; D005910:Glioma / Q000150:complications / Q000000981:diagnostic imaging*; D006801:Humans; D016483:Lymphoma, AIDS-Related / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013794:Thallium Radioisotopes; D015899:Tomography, Emission-Computed, Single-Photon
chemical_list: D005710:Gallium Radioisotopes; D013794:Thallium Radioisotopes