title: Reduced value of thallium-201 single-photon emission computed tomography in the management of HIV-related focal brain lesions in the era of highly active antiretroviral therapy.
abstract: To evaluate the diagnostic value of thallium-201 single-photon emission computed tomography (201Tl SPECT) in the management of focal brain disorders in the era of highly active antiretroviral therapy (HAART), a validation study of diagnostic procedure was performed in a tertiary clinical care center in Italy. Thirty-eight consecutive HIV-infected patients with neurological impairment and focal brain lesions (FBL) were enrolled in a prospective evaluation and underwent diagnostic procedures according to a standardized protocol based on modified previously released guidelines. Six out of seven PCNSL presented high uptake at 201Tl SPECT [sensitivity 86% (95% CI 42-99); specificity 77% (95% CI 58-90); positive predictive value (PPV) 46% (95% CI 20-74); negative predictive value (NPV) 96% (95% CI 78-100)]. Among toxoplasmic encephalitis (TE) cases 14 showed no uptake and 5 showed an increased uptake [sensitivity 74% (95% CI 49-90); specificity 42% (95% CI 21-66); PPV 56% (95% CI 35-75); NPV 61% (95% CI 32-85)]. Patients taking HAART were more likely to display an increased uptake of 201Tl in the cerebral lesions than patients without HAART (OR 5.07; 95% CI 1.19-21.5). Considering only the patients with diagnosis of TE, 60% of patients who showed high radionuclide uptake were taking HAART, while 79% of patients without relevant uptake were not taking HAART. As a result of the impact of HAART, the diagnostic value of 201Tl SPECT in the management of HIV-associated FBL could be substantially reduced. This observation suggests that in HAART-treated patients, this diagnostic tool be used only when combined with other more specific diagnostic markers.
authors.affiliation: Clinical Department, National Institute for Infectious Diseases Lazzaro Spallanzani, IRCCS, Rome, Italy.
authors.forename: Maria Letizia
authors.initials: ML
authors.lastname: Giancola
authors.forename: Elisa Busi
authors.initials: EB
authors.lastname: Rizzi
authors.forename: Riccardo
authors.initials: R
authors.lastname: Schiavo
authors.forename: Patrizia
authors.initials: P
authors.lastname: Lorenzini
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Schininà
authors.forename: Lucia
authors.initials: L
authors.lastname: Alba
authors.forename: Bruno
authors.initials: B
authors.lastname: Del Grosso
authors.forename: Beniamino
authors.initials: B
authors.lastname: Gigli
authors.forename: Silvia
authors.initials: S
authors.lastname: Rosati
authors.forename: Lucio
authors.initials: L
authors.lastname: Mango
authors.forename: Corrado
authors.initials: C
authors.lastname: Bibbolino
authors.forename: Andrea
authors.initials: A
authors.lastname: Antinori
mesh_terms: D015526:AIDS Dementia Complex / Q000000981:diagnostic imaging*; D000328:Adult; D019380:Anti-HIV Agents / Q000627:therapeutic use*; D023241:Antiretroviral Therapy, Highly Active; D003943:Diagnostic Techniques, Neurological; D005260:Female; D015658:HIV Infections / Q000188:drug therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D013794:Thallium Radioisotopes; D015899:Tomography, Emission-Computed, Single-Photon; D016781:Toxoplasmosis, Cerebral / Q000175:diagnosis
chemical_list: D019380:Anti-HIV Agents; D013794:Thallium Radioisotopes