The role of ¹⁸F-fluorodeoxyglucose positron-emission tomography/computed tomography in the diagnosis of postoperative hardware-related spinal infections

Background: Implant-related spinal infections are a surgical complication associated with high morbidity. Due to infection, hardware removal may be necessary, which could lead to pseudarthrosis and the loss of stability and alignment. Objectives: To evaluate the accuracy and diagnostic value of ¹⁸F-fluorodeoxyglucose positron-emission tomography/ computed tomography (¹⁸F-FDG PET/CT) in the workup of patients with suspected implant-related infections of the spine and to assess the clinical impact of PET/CT results on the management of these infections. Methods: The study included nine consecutive patients with a history of spinal surgery who underwent PET/CT for evaluation of suspected spinal implant related infection. All imaging studies were performed between January 2011 and December 2013. All ¹⁸F-FDG PET/CT scans were performed on an 8 slice PET/CT following an ¹⁸F-FDG injection. Images were scored both visually and semi-quantitatively by a radiology expert. Results were compared to additional imaging studies when available, which were correlated to clinical and bacteriological findings allowing calculation of sensitivity, specificity and accuracy. Results: Among the patients, five experienced hardware-related spinal infection. ¹⁸F-FDG PET/CT sensitivity was 80%, specificity 100%, and accuracy 88.9%. One scan produced a false negative; however, a second PET/CT scan revealed an infection. Conclusions: PET/CT was found to be valuable for the diagnosis of postoperative hardware-related spinal infection, especially when other imaging modalities were uninformative or inconclusive. As such, PET/CT could be useful for management of infection treatment.