18F-FDG PET/CT-imaging of left ventricular assist device infection: a retrospective quantitative intrapatient analysis.

BACKGROUND: Despite the use of 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT), diagnosis of a driveline infection in ventricular assist device (LVAD) recipients remains challenging. Our aim was to evaluate the potential of a baseline 18F-FDG PET/CT (prior to an infection) for the diagnosis of an LVAD-related infection. METHODS: We retrospectively selected all LVAD recipients who had undergone two consecutive whole-body 18F-FDG PET/CT examinations between January 2010 and December 2016. PET/CT was analyzed qualitatively (uptake pattern) and semi-quantitatively (SUVmax and ∆SUVmax). SUVmax was measured and compared in five distinctive volumes of interest along the LVAD driveline. An SUVmax threshold was calculated. Final diagnosis was made by clinical examination, microbiological parameters, and molecular imaging. RESULTS: Thirty patients were enrolled (mean age 54 ± 12 years; 26 male). Mean difference in SUVmax for all five positions between the first and the second PET/CT along the driveline was significantly higher in patients with an LVAD-related infection (mean ∆SUVmax = 4.38 ± 1.44) compared to those without a driveline infection (mean ∆SUVmax = 0.03 ± 0.43), P < 0.05. Applying ROC analysis, an SUVmax threshold of 3.88 resulted in a sensitivity and specificity of 100%, respectively. There were three distinctive uptake patterns in patients with a driveline infection. CONCLUSION: PET/CT diagnosis in the context of an LVAD-related infection can be improved by comparison to a baseline examination using a distinctive SUVmax threshold.