Objective: The aim of this study was to review the available literature on the reliability of contemporary magnetic resonance imaging (MRI) techniques in the assessment of high-risk features of endometrial carcinoma, that is, deep myometrial invasion, cervical stromal involvement, and lymph node metastasis.
Methods: The PubMed and Scopus databases were searched for studies published before March 2014. Studies on plain MRI were excluded.
Results: Fifty-two eligible studies were identified. For the assessment of deep (≥ 50%) myometrial invasion (50 studies, 3720 patients), the pooled sensitivity, specificity, positive predictive value, and negative predictive value were 80.7%, 88.5%, 77.6%, and 89.5%, respectively, by random-effects analysis. For predicting cervical stromal involvement (12 studies, 1153 patients), the pooled values were 57.0%, 94.8%, 68.7%, and 90.5%, respectively. For lymph node metastasis on a per-patient basis (10 studies, 862 patients), they were 43.5%, 95.9%, 66.3%, and 92.2%, respectively. In a meta-regression analysis, dynamic imaging was associated with a higher sensitivity in detecting deep myometrial invasion, as compared with contrast-enhanced imaging (P = 0.021). The improvement by diffusion-weighted imaging was of a borderline significance (P = 0.057). Significant small-study effects were found for the sensitivity of MRI in detecting deep myometrial invasion (P < 0.0001) and cervical stromal involvement (P = 0.049).
Conclusions: Considering the poor-to-moderate sensitivity of MRI in detecting high-risk features of endometrial carcinoma, patients with negative findings on MRI may not safely forgo surgical staging unless the findings are confirmed by a backup method. The high specificities allow the targeting of staging procedures by MRI alone in patients with positive findings. Compared with contrast-enhanced imaging, dynamic and diffusion-weighted imaging may be more reliable in the radiological staging of endometrial carcinoma.