Positron emission tomography objective parameters for assessment of left ventricular assist device infection using 18F-FDG PET/CT.

ABSTRACT

Left ventricular assist device (LVAD) is a life-saving therapy, but it poses a substantial infection risk. Current evaluation of LVAD infection with 18F-FDG PET/CT is predominately subjective. We present qualitative and semi-quantitative 18F-FDG PET/CT parameters for early detection of LVAD infection and site localization. We retrospectively reviewed all 25 LVAD patients at our institution who had undergone 18F-FDG PET/CT imaging between 2014 and 2018. LVADs were subdivided into five assessed regions driveline exit site, subcutaneous driveline, LVAD pump, LVAD inflow, and LVAD outflow cannulae. Ultimate diagnosis of LVAD infection was determined by a multidisciplinary primary care team. Qualitative and semi-quantitative analysis of PET/CT data were performed, including calculation of the standardized uptake value maximum, mean, and peak (SUVmax, SUVmean, and SUVpeak, respectively), as well as metabolic tumor volume (MTV), and total lesion glycolysis (TLG). A total of 14 patients presented with symptoms of infection, and LVAD infection was ultimately diagnosed in 19 of the 25 cases. All cases were correctly identified on 18F-FDG PET/CT with no false positive and no false negative cases, corresponding to a sensitivity and specificity of 100%. The mean SUVmax range at noninfected sites was 2.5-3.4, and the range was 5.7-8.1 at infected sites, resulting in a significant difference (P < 0.01) at all LVAD regions. 18F-FDG PET/CT is a useful adjunctive tool for assessment of LVAD infection and infection localization, which is crucial for clinical management. A cut-off SUVmax 5 is recommended to help diagnose LVAD infection.