Abstract
BACKGROUND: The use of fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) in the assessment of infectious diseases has been increasing, yet research on its impact during follow-up remains scarce. OBJECTIVES: To evaluate the impact of follow-up FDG-PET/CT on managing focal infectious diseases. DESIGN: An observational, retrospective, single-center study. METHODS: Patients who underwent FDG-PET/CT for the diagnosis of focal infection and had a follow-up FDG-PET/CT between January 1, 2012 and October 31, 2023 were included. The impact of follow-up FDG-PET/CT on management was defined as findings leading to any change in antibiotic treatment or any source control interventions (impact group), which was compared to follow-up FDG-PET/CT that did not lead to any change in management (no-impact group). RESULTS: Eighty-nine patients were included, with a mean age of 62 ± 14.6 years. The most common infections were of skeletal (n = 34, 38.2%) and cardiovascular origin (n = 16, 17.9%). Overall, the follow-up FDG-PET/CT findings resulted in changing the management in 57 (64%) patients. It led to antibiotic change in 54 (60.7%) patients, and to source control intervention in 29 (32.6%) patients. Demographic and clinical characteristics of the impact group and the no-impact group were similar, except for a significantly higher rate of gram-positive bacteremia, which was detected in 26 (93%) patients with bacteremia in the impact group (mostly Staphylococcus aureus) compared to 8 (57%) of patients in the no-impact group, p = 0.01. Impact of FDG-PET/CT was associated with worsening clinical status, observed in 33 patients (57.9%) in the impact group compared to 6 (18.8%) in the no-impact group, p = 0.002. CONCLUSION: Follow-up FDG-PET/CT appears to have a significant impact on managing selected patients with focal infections, particularly those caused by gram-positive bacteremia or with an unfavorable clinical course.