Head-to-Head Comparison of the Diagnostic Performance of FDG PET/CT and FDG PET/MRI in Patients With Cancer: A Systematic Review and Meta-Analysis.

The available evidence on the use of FDG PET/MRI performed using an integrated system in patients with cancer has grown substantially. The purpose of this study was to perform a systematic review and meta-analysis comparing the diagnostic performance of FDG PET/CT and FDG PET/MRI in patients with cancer. MEDLINE, Embase, and the Cochrane Database of Systematic Reviews were searched for studies reporting a head-to-head comparison of the diagnostic performance of FDG PET/CT and FDG PET/MRI in patients with cancer from July 1, 2015, to January 25, 2023. The two modalities' diagnostic performance was summarized, stratified by performance end point. For end points with sufficient data, a meta-analysis was performed using bivariate modeling to produce summary estimates of pooled sensitivity and specificity. For the remaining end points, reported performance in individual studies was recorded. The systematic review included 29 studies with a total of 1656 patients. For patient-level detection of regional nodal metastases (five studies), pooled sensitivity and specificity for PET/MRI were 88% (95% CI, 74-95%) and 92% (95% CI, 71-98%), respectively, and for PET/CT were 86% (95% CI, 70-94%) and 86% (95% CI, 68-95%). For lesion-level detection of recurrence and/or metastases (five studies), pooled sensitivity and specificity for PET/MRI were 94% (95% CI, 78-99%) and 83% (95% CI, 76-88%), respectively, and for PET/CT were 91% (95% CI, 77-96%) and 81% (95% CI, 72-88%). In individual studies not included in the meta-analysis, PET/MRI in comparison with PET/CT showed staging accuracy in breast cancer of 98.0% versus 74.5% and in colorectal cancer of 96.2% versus 69.2%; sensitivity for primary tumor detection in cervical cancer of 93.2% versus 66.2%; and sensitivity, specificity, and accuracy for lesion-level liver metastasis detection of 91.1-98.0% versus 42.3-71.1%, 100.0% versus 83.3-98.6%, and 96.5-98.2% versus 44.7-86.7%, respectively. In three studies, management was more commonly impacted by information from PET/MRI (5.2-11.1%) than PET/CT (0.0-2.6%). PET/MRI showed comparable or superior diagnostic performance versus PET/CT across a range of cancers and end points. The findings help to identify clinical settings where PET/MRI may provide clinical benefit for oncologic evaluation. Prospective Register of Systematic Reviews CRD42023433857.