Assessment of deep myometrial invasion of endometrial cancer on MRI: added value of second-opinion interpretations by radiologists subspecialized in gynaecologic oncology.

OBJECTIVE: To investigate the added value of secondary reports issued by radiologists subspecializing in gynaecologic imaging for determining deep myometrial invasion of endometrial cancer on MRI.
METHODS: Initial (from referring institutions) and secondary (by subspecialized radiologists) interpretations of MRI of 55 patients with endometrial cancer were retrospectively reviewed. A radiologist blinded to clinicopathological information assessed both reports for the presence of deep myometrial invasion. Reference standard was based on hysterectomy specimens. Kappa coefficients (k) were used to measure their concordance. McNemar testing and receiver operating characteristic (ROC) analysis was used to compare sensitivities, specificities and areas under the curves (AUCs).
RESULTS: Deep myometrial invasion was present in 25 (45.5 %) patients. Among 27.3 % (15/55; k = 0.458) patients with discrepant results, secondary interpretations were correct in 10 (66.7 %) cases. Sensitivity was higher in secondary than in initial reports (76.0 % vs. 48.0 %, p = 0.039) while no significant difference was seen in specificity (70.0 % vs. 76.7 %, p = 0.668). At ROC analysis, there was a tendency for higher AUCs in secondary reports (0.785 vs 0.669, p = 0.096).
CONCLUSION: Secondary readings of MRI by subspecialized gynaecologic oncologic radiologists may provide incremental value in determining deep myometrial invasion of endometrial cancer. KEY POINTS: • Deep myometrial invasion is an important prognostic factor in endometrial cancer. • Assessment of deep myometrial invasion is often discrepant between initial and secondary reports. • Secondary reports showed higher sensitivity and accuracy. • Secondary review of MRI may provide incremental value in endometrial cancer patients.