Clinical role and accuracy of 18F-FDG PET in evaluating disease activity in patients with chronic inflammatory bowel disease: an updated systematic review and a bivariate meta-analysis

Abstract

Objective markers of disease activity are crucial for clinical decision making in patients with chronic inflammatory bowel diseases (IBD). We aimed to perform an updated systematic review on the clinical role of 18F-FDG PET in evaluating disease activity in patients with IBD and a bivariate meta-analysis on its accuracy in this setting. A comprehensive computer literature search of studies published through December 2016 about the clinical role of 18F-FDG PET in patients with IBD was performed using the following search algorithm: A) PET OR positron emission tomography OR FDG AND B) inflammatory bowel OR Crohn OR ulcerative colitis OR IBD. All included articles were reviewed. Pooled sensitivity, specificity, positive and negative likelihood ratios (LR+ and LR−) and diagnostic odds ratio (DOR) of 18F-FDG PET in evaluating disease activity in patients with IBD on a per-segment-based analysis were calculated. Furthermore, the summary receiver operating characteristic (sROC) curve has been evaluated. Twenty-three studies on the use of 18F-FDG PET in evaluating disease activity in patients with IBD (584 cases) were discussed in the systematic review. The meta-analysis of nine selected studies provided the following results on a per-segment-based analysis: sensitivity was 85.6% [95% confidence interval (95% CI) 76–92%], specificity 85.5% (95% CI 75–92%), LR+ 5.59 (95% CI 3.29–9.5), LR− 0.15 (95% CI 0.07–0.32), DOR 34.64 (95% CI 13.03–92.08). Heterogeneity among the selected studies was found. 18F-FDG PET demonstrated good accuracy in evaluating the disease activity in patients with IBD and this method could have a clinical impact in patients with IBD. Large multicenter studies and cost-effectiveness analyses are needed to confirm the role of this functional imaging method in this setting.