18F-FDG PET in the Diagnosis of Vascular Prosthetic Graft Infection: A Diagnostic Test Accuracy Meta-Analysis

Abstract

For the diagnosis of vascular prosthetic graft infection (VPGI), an intra-operative peri-graft biopsy is often required. Controversy exists regarding the use of imaging techniques in the diagnostic process. This study aimed to evaluate the diagnostic accuracy of 18-fluorine fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) in VPGI. A systematic search of electronic databases was conducted, applying a combination of free text and controlled vocabulary searches adapted to thesaurus headings, search operators, and limits to identify studies assessing the use of 18F-FDG PET in the diagnosis of VPGI. A meta-analysis was conducted using a mixed effects logistic regression bivariate model. Twelve studies were identified reporting a total of 433 prostheses, of which 202 were proven to be infected. Analysis of PET scan was performed using five different methods: graded uptake, focal uptake, maximum standardised uptake value (SUVmax), tissue to background ratio (TBR), and dual time point (DTP). The pooled estimates for sensitivity and specificity for graded uptake were 0.89 (95% CI 0.73-0.96) and 0.61 (95% CI 0.48-0.74), respectively; they were 0.93 (95% CI 0.83-0.97) and 0.78 (95% CI 0.53-0.92) for focal uptake; 0.98 (95% CI 0.42-0.99) and 0.80 (95% CI 0.70-0.88) for SUVmax; 0.57 (95% CI 0.39-0.73) and 0.76 (95% CI 0.64-0.85) for TBR; and 1.00 (95% CI 0.48-1.00) and 0.88 (95% CI 0.68-0.97) for DTP. Sensitivity analysis including studies that investigated the diagnostic accuracy of PET combined with computed tomography (CT) showed higher sensitivity and specificity for focal uptake, graded uptake, and SUVmax than 18F-FDG PET alone. This meta-analysis suggests that 18F-FDG PET has a high sensitivity in diagnosing VPGI and its accuracy can be further increased by combining PET with CT.