C-reactive protein levels can predict positive 18F-FDG PET/CT findings that lead to management changes in patients with bacteremia

Abstract

Background/purpose: Bacteremia portends high rates of morbidity and mortality. Although ¹⁸F-fluorodeoxyglucose positron emission tomography and computed tomography (¹⁸F-FDG PET/CT) imaging has clinical value in assessing fever of unknown origin, its usefulness in bacteremia has not been entirely elucidated. We therefore designed the current single-center retrospective study to investigate 1) the clinical value of ¹⁸F-FDG PET/CT imaging in assessing bacteremia and 2) the association between laboratory data and imaging findings.

Methods: We examined 102 patients with bacteremia who had undergone ¹⁸F-FDG PET/CT imaging. The patients' clinical and laboratory data were reviewed and analyzed in relation to ¹⁸F-FDG PET/CT findings. Patients showing positive results underwent quantitative measurements of ¹⁸F-FDG uptake.

Results: Positive ¹⁸F-FDG PET/CT findings were identified in 74 (72.5%) patients, and 40 (54.1%) underwent modified treatment or management because of the imaging results (p = 0.003). Positive ¹⁸F-FDG PET/CT findings were significantly associated with higher white blood cell (WBC) counts and C-reactive protein (CRP) levels (p = 0.012 and < 0.001, respectively). Notably, CRP levels accurately predicted (area under curve = 0.752; p < 0.001) positive ¹⁸F-FDG PET/CT findings (optimal cut-off point: 54.025 mg/L).

Conclusion: A majority (54.1%, n = 40) of the patients with positive ¹⁸F-FDG PET/CT results underwent treatment modifications; they accounted for most cases (87%) of management changes in our cohort. Leukocytosis and increased CRP levels are significantly associated with positive ¹⁸F-FDG PET/CT findings in patients with bacteremia. CRP levels >54.025 mg/L were accurate predictors of positive ¹⁸F-FDG PET/CT results.

Keywords: (18)F-fluorodeoxyglucose positron emission tomography and computed tomography; Bacteremia; C-reactive protein.