2-Deoxy-2-[ ¹⁸ F]-fluoro-D-glucose (2-[ ¹⁸ F]FDG) positron emission tomography/computed tomography (PET/CT) is a hybrid imaging tool with an emerging role in the study of several infectious and inflammatory diseases. Its role in critically ill patients admitted to the intensive care unit (ICU) is only marginally investigated. This study aimed to investigate the diagnostic performance and the clinical impact of 2-[ ¹⁸ F]FDG PET/CT in the management of critically ill patients with suspected infections of unknown origin.
We retrospectively included 47 ICU patients (mean age 63.6 years, 33 males) who underwent a 2-[ ¹⁸ F]FDG PET/CT to look for infection foci. We calculated the diagnostic performance of PET/CT expressed as sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy. As reference standard, final diagnosis based on microbiological/pathologic data or on clinical follow-up was taken. Moreover, we investigated the impact of PET/CT on clinical management and the association of PET/CT with the main clinical, epidemiological and biochemical parameters.
The overall 2-[ ¹⁸ F]FDG PET/CT sensitivity in detecting infectious foci was 80% (95%CI 64-91%), specificity 75% (95%CI 35-97%), PPV 94% (95%CI 83-93%), NPV 43% (95%CI 26-61%) and accuracy 79% (95%CI 65-90%). The absence of kidney failure, increase leukocyte count and low glucose level at the time of PET were significantly associated with true positive PET/CT. No adverse events during the transport and PET/CT procedure were registered.
PET/CT demonstrated to be an accurate toll for the study of critically ill ICU patients with suspected infections. Kidney failure, leukocyte count and blood glucose were associated with true positive PET/CT.