BACKGROUND Fever of unknown origin (FUO) in pediatric patients remains a persistent diagnostic challenge, despite advances in imaging and laboratory techniques. Although positron emission tomography/computed tomography (PET/CT) has demonstrated substantial diagnostic value in adult populations, its utility in pediatric FUO is less clearly defined. This study aimed to assess the contribution of PET/CT to the diagnosis of FUO in hospitalized children and identify predictive clinical and laboratory factors for its diagnostic utility. METHODS This retrospective cohort study reviewed medical records of pediatric patients (aged 0–18 years) diagnosed with FUO who underwent fluorodeoxyglucose PET/CT imaging between 2010 and 2022, at 3 medical centers in Israel. Clinical presentations, laboratory findings, and final diagnoses were compared between cases where PET/CT contributed to diagnosis or did not. RESULTS A total of 112 patients were included. PET/CT contributed to diagnosis in 51 (45.5%) cases. Among these, infectious etiologies predominated (54.9%). In contrast, among noncontributory PET/CT cases, rheumatologic diseases were more common (66.6%). Factors associated with higher diagnostic yield included immunodeficiency, low hemoglobin, elevated lactate dehydrogenase, and low serum albumin. Conversely, presence of rash or arthritis was more common in nondiagnostic cases. PET/CT influenced treatment decisions in 40 (35.7%) patients. No significant differences in inflammatory markers levels (C-reactive protein, erythrocyte sedimentation rate, ferritin) were observed between the groups. CONCLUSIONS PET/CT demonstrates a substantial diagnostic yield in pediatric FUO, particularly when certain predictive clinical and laboratory factors are present. It may represent a useful tool in the evaluation of unresolved cases after conventional investigations had failed to identify the cause of fever.
Berlak et al. (Tue,) studied this question.