Head-to-Head Comparison of 68Ga-Citrate and 18F-FDG PET/CT for Detection of Infectious Foci in Patients with Staphylococcus aureus Bacteraemia

Abstract

<p><em>Purpose.</em> This study evaluated the potential of ⁶⁸Ga-citrate positron emission tomography/computed tomography (PET/CT) for the detection of infectious foci in patients with <em>Staphylococcus aureus</em> bacteraemia by comparing it with 2-[¹⁸F]fluoro-2-deoxy--glucose (¹⁸F-FDG) PET/CT. <em>Methods.</em> Four patients admitted to hospital due to <em>S. aureus </em>bacteraemia underwent both ¹⁸F-FDG and ⁶⁸Ga-citrate whole-body PET/CT scans to detect infectious foci. <em>Results.</em> The time from hospital admission and the initiation of antibiotic treatment to the first PET/CT was 4–10 days. The time interval between ¹⁸F-FDG and ⁶⁸Ga-citrate PET/CT was 1–4 days. Three patients had vertebral osteomyelitis (spondylodiscitis) and one had osteomyelitis in the toe; these were detected by both ¹⁸F-FDG (maximum standardised uptake value [SUV_max 6.0 ± 1.0] ) and ⁶⁸Ga-citrate (SUV_max 6.8 ± 3.5, <em>P</em> = 0.61). Three patients had soft tissue infectious foci, with more intense ¹⁸F-FDG uptake (SUV_max 6.5 ± 2.5) than ⁶⁸Ga-citrate uptake (SUV_max 3.9 ± 1.2, <em>P</em> = 0.0033). <em>Conclusions</em>. Our small cohort of patients with S. aureus bacteraemia revealed that ⁶⁸Ga-citrate PET/CT is comparable to ¹⁸F-FDG PET/CT for detection of osteomyelitis, whereas ¹⁸F-FDG resulted in a higher signal for the detection of soft tissue infectious foci.</p>