¹⁸F-FDG PET/CT Optimizes Treatment in Staphylococcus Aureus Bacteremia and Is Associated with Reduced Mortality

Abstract

Metastatic infection is an important complication of bacteremia (SAB). Early diagnosis of metastatic infection is crucial, because specific treatment is required. However, metastatic infection can be asymptomatic and difficult to detect. In this study, we investigated the role ofF-FDG PET/CT in patients with SAB for detection of metastatic infection and its consequences for treatment and outcome. All patients with SAB at Radboud University Medical Center were included between January 2013 and April 2016. Clinical data and results ofF-FDG PET/CT and other imaging techniques, including echocardiography, were collected. Primary outcomes were newly diagnosed metastatic infection by F-FDG PET/CT, subsequent treatment modifications, and patient outcome. A total of 184 patients were included, and F-FDG PET/CT was performed in 105 patients, of whom 99 had a high-risk bacteremia.F-FDG PET/CT detected metastatic infectious foci in 73.7% of these high-risk patients. In 71.2% of patients with metastatic infection, no signs and symptoms suggesting metastatic complications were present before F-FDG PET/CT was performed.F-FDG PET/CT led to a total of 104 treatment modifications in 74 patients. Three-month mortality was higher in high-risk bacteremia patients without F-FDG PET/CT performed than in those in whomF-FDG PET/CT was performed (32.7% vs. 12.4%, = 0.003). In multivariate analysis,F-FDG PET/CT was the only factor independently associated with reduced mortality ( = 0.005; odds ratio, 0.204; 95% confidence interval, 0.066-0.624). A higher comorbidity score was independently associated with increased mortality ( = 0.003; odds ratio, 1.254; 95% confidence interval, 1.078-1.457). F-FDG PET/CT is a valuable technique for early detection of metastatic infectious foci, often leading to treatment modification. PerformingF-FDG PET/CT is associated with significantly reduced 3-mo mortality.

Persistent bacteraemia caused byStaphylococcus aureusin the gall bladder

“…Compared with matched historical controls for whom no 18-FDG-PET/CT was performed, a significantly higher number of metastatic infectious foci were diagnosed in the study group (67.8% vs 35.7%, P<0.01), and the mortality rate at 6 months was lower (19.1% vs 32.2%, P=0.014) 21. A 2017 study from the Netherlands found that 18 F-FDG PET/CT detected metastatic infectious foci in 73 of 99 patients with high-risk SAB, 71.2% of which were asymptomatic 22 . 18 F-FDG PET/CT led to treatment modifications in 74 of the 99 high-risk patients and 3-month mortality was lower compared with those who did not undergo 18 F-FDG PET/CT (12.4% vs 32.7%, P=0.003) 22.…”

“…A 2017 study from the Netherlands found that 18 F-FDG PET/CT detected metastatic infectious foci in 73 of 99 patients with high-risk SAB, 71.2% of which were asymptomatic 22 . 18 F-FDG PET/CT led to treatment modifications in 74 of the 99 high-risk patients and 3-month mortality was lower compared with those who did not undergo 18 F-FDG PET/CT (12.4% vs 32.7%, P=0.003) 22. Although we considered PET/CT and tagged WBC imaging modalities, we chose tagged WBC based on our desire to maximise test specificity in the setting of a high pretest probability of an undrained source of infection, particularly in a patient with concern for osteomyelitis (in the setting of toe dry gangrene) and presence of a vascular graft—two clinical scenarios where tagged WBC imaging is thought to be useful 23 24…”

Surviving sepsis campaign international guidelines for the management of septic shock and sepsis-associated organ dysfunction in children

“…For example, optimal duration of treatment for endocarditis caused by methicillin-susceptible S. aureus may be shorter than for that caused by MRSA [136]. Similarly, although 7-10 days of therapy is appropriate for treatment of uncomplicated gram-negative bacteremia in immunocompetent hosts [137,138], uncomplicated S. aureus bacteremia requires a longer course of therapy to effect cure [139][140][141], likely because of unrecognized seeding [142]. Integrity of host immunity may also affect clearance of infection, so antimicrobial therapy for infection in neutropenic pediatric patients with cancer is often continued until resolution of neutropenia [78].…”

18F-FDG PET/CT–Guided Treatment Duration in Patients with High-Risk Staphylococcus Aureus Bacteremia: A Proof of Principle

“…St aphylococcus aureus bacteremia (SAB) is a serious infection, associated with a 30-d overall mortality of 20% (1). Metastatic infection, occurring in 16%-73% of patients, is the most important determinant of morbidity and mortality (2)(3)(4)(5)(6)(7)(8). Prolonged bacteremia, delayed clinical response to antibiotic treatment, and the presence of foreign body materials are associated with a complicated course.…”