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

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.