Early diagnosis of cardiac implantable electronic device generator pocket infection using 18F-FDG-PET/CT

Aims To examine the utility of F-18-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDGPET/CT) in the early diagnosis of cardiac implantable electronic device (CIED) generator pocket infection. Methods and results A total of 86 patients with CIEDs were evaluated with F-18-FDG PET/CT imaging: 46 with suspected generator pocket infection and 40 without any history of infection. F-18-FDG activity in the region of the generator pocket was expressed as a semi-quantitative ratio (SQR)-defined as the maximum count rate around the CIED divided by the mean count rate between normal right and left lung parenchyma. All patients underwent standard clinical management, independent of the PET/CT result. Patients with suspected generator pocket infection that required CIED extraction (n = 32) had significantly higher F-18-FDG activity compared with those that did not (n = 14), and compared with controls (n = 40) [SQR: 4.80 (3.18-7.05) vs. 1.40 (0.88-1.73) vs. 1.10 (0.98-1.40), respectively; P < 0.001]. On receiver operator characteristic analysis, SQR had a high diagnostic accuracy (area under curve = 0.98) for the early identification of patients with confirmed infection (i.e. those ultimately needing extraction)-with an optimal SQR cut-off value of >2.0 (sensitivity = 97%; specificity = 98%). Conclusion This study highlights the potential benefits of evaluating patients with suspected CIED generator pocket infection using F-18-FDG PET/CT. In this study, F-18-FDG PET/CT had a high diagnostic accuracy in the early diagnosis of CIED generator pocket infection, even where initial clinical signs were underwhelming.