Objectives
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.
Methods
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.
Results
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.
Conclusions
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.