COMPARISON BETWEEN TL-201-CHLORIDE AND TC-99(M)-SESTAMIBI SPET BRAIN IMAGING FOR DIFFERENTIATING INTRACRANIAL LYMPHOMA FROM NONMALIGNANT LESIONS IN AIDS PATIENTS
Sy. Naddaf et al., COMPARISON BETWEEN TL-201-CHLORIDE AND TC-99(M)-SESTAMIBI SPET BRAIN IMAGING FOR DIFFERENTIATING INTRACRANIAL LYMPHOMA FROM NONMALIGNANT LESIONS IN AIDS PATIENTS, Nuclear medicine communications, 19(1), 1998, pp. 47-53
The aim of this study was to compare Tl-201-chloride and Tc-99(m)-sest
amibi (MIBI) SPET brain imaging for differentiating brain lymphoma fro
m other intracranial lesions in AIDS patients. Both studies were perfo
rmed on the same day in 17 AIDS patients with intracranial enhancing l
esions on either CT or MRI. Eleven patients underwent brain biopsy and
six patients were followed clinically. We calculated the radiopharmac
eutical uptake ratio of the lesion to that on the contralateral side w
ith the guidance of CT or MRI findings. Ratios of 1.5 or more were con
sidered to represent malignant lesions and ratios <1.5 were considered
to represent benign lesions. Biopsy revealed four cases of lymphoma,
four cases of toxoplasmosis and two cases of progressive multi-focal l
eukoencephalopathy; one biopsy yielded necrosis. Both the MIBI and Tl-
201 studies yielded no false-negative cases of lymphoma (sensitivity 1
00%). Of the 13 non-lymphoma cases, the Tl-201 studies showed seven tr
ue-negative cases (specificity 54%) and the MIBI studies showed nine t
rue-negative cases (specificity 69%). The biopsies of the false-positi
ve cases (toxoplasmosis) showed a pattern of healing after medical tre
atment. We conclude that MIBI is more helpful than Tl-201 because of h
igher specificity and equal sensitivity. The medical treatment of toxo
plasmosis is a cause of false-positive Tl-201 and MIBI studies.