Positron emission tomography objective parameters for assessment of left ventricular assist device infection using...

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 (SUV_max, SUV_mean, and SUV_peak, 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 SUV_max 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 SUV_max 5 is recommended to help diagnose LVAD infection.