The diagnostic performance of 18F-FDG PET/CT, CT and MRI in the treatment evaluation of ablation therapy for colorectal liver metastases: A systematic review and meta-analysis

Abstract

Purpose Uncertainty exists regarding the optimal imaging modality for timely detection of disease progression (DP) after ablation therapy for colorectal liver metastases. We evaluated the diagnostic accuracy of 18F-FDG PET(/CT), CT and MRI for detection of DP following ablation therapy. Methods A systematic search was performed on May 18, 2016. The analysis included studies that reported on the diagnostic accuracy of 18F-FDG PET(/CT), CT and/or MRI for post-ablative evaluation of patients with liver metastases. Primary outcome was the diagnostic accuracy of the imaging modalities for detection of DP. Methodological quality was assessed using the QUADAS-2 tool. Pooled sensitivities and specificities were estimated using bivariate random-effects models. Results Ten studies were included in the meta-analysis, including seven comparative studies. Nine reported data on diagnostic accuracy of 18F-FDG PET(/CT), seven on CT imaging. Only two studies reported the diagnostic accuracy of MRI, hence not included in the meta-analysis. Quality assessment raised concerns about the risk of bias regarding the use of the reference standard, blinding of the index tests and the follow-up time. Pooled sensitivity was respectively 84.6% (75.0–90.6) and 53.4% (29.0–76.4) for 18F-FDG PET(/CT) and CT (P = 0.005). Pooled specificity was respectively 92.4% (86.5–95.9) and 95.7% (87.5–98.6) (P = 0.392). Conclusion 18F-FDG PET/(CT) yields a higher sensitivity for detecting DP after ablation therapy compared with CT and has a comparably high specificity. These findings indicate that the use of 18F-FDG PET(/CT) in this setting particularly allows for minimization of the false-negative rate compared with CT without compromising the low false-positive rate.