Role and interpretation of fluorodeoxyglucose-positron emission tomography/computed tomography in HIV-infected patients with fever of unknown origin: a prospective study
Correspondence: Charlotte Martin, CHU Saint-Pierre, Infectious Diseases Dept, 322 Rue Haute, 1000 Brussels, Belgium. Tel: 00 32 2535 41 30; fax: 00 32 2539 36 14; e-mail: email@example.com
The aim of the study was to evaluate prospectively the usefulness of fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) in investigation of fever of unknown origin (FUO) in HIV-positive patients and to determine whether HIV viraemia impacts on FDG-PET/CT performance.
The FDG-PET/CT results of 20 HIV-infected patients with FUO were analysed and compared with the FDG-PET/CT results of 10 HIV-infected viraemic patients without FUO. The performance of FDG-PET/CT for identifying the aetiology of FUO was assessed. Final diagnosis for FUO was based on histopathology, microbiological assays, or clinical and imaging follow-up.
FDG-PET/CT contributed to the diagnosis or exclusion of a focal aetiology of the febrile state in 80% of patients with FUO. The presence of increased FDG uptake in the central lymph node has 100% specificity for focal aetiology of fever, even in viraemic patients. The absence of hypermetabolic central lymph nodes in FUO patients has 100% negative predictive value for focal disease. Lymph node biopsy in central hypermetabolic areas allowed, in 100% of cases, identification of underlying disease in patients with FUO. Biopsy of peripheral lymph nodes should be performed in lymph nodes with maximum standardized uptake value (SUVmax) ≥ 6–8 (sensitivity 62.5%; specificity 75%) and avoided in lymph nodes with SUVmax = 0–4 (specificity 0%). High HIV viraemia does not prevent correct interpretation of FDG-PET/CT.
As in HIV-negative patients, we confirm the usefulness of FDG-PET/CT in investigation of FUO in HIV-positive patients even if they are viraemic.