Clinical utility of magnetic resonance imaging and the preoperative identification of low risk endometrial cancer.
BACKGROUND: Magnetic resonance imaging (MRI) is reported to offer the best imaging of local disease in endometrial cancer. We audited MRI scans to identify their clinical utility, particularly in the preoperative identification of 'low risk' endometrial cancer (grade one or two endometrioid tumours confined to the inner half of the myometrium). AIM: To correlate histological and MRI findings and to establish our ability to preoperatively identify women with 'low risk' tumours. STUDY DESIGN: A retrospective audit of MRI scans in women with a new diagnosis of endometrial cancer from July 1998 to November 2002. Radiology and pathology reports and surgical staging data were extracted. Independently a team of radiologists reviewed MRI films and the findings were compared to pathology. RESULTS: Thirty-nine patients were included. Only 10% of original reports contained all the clinically relevant information. On review, the sensitivity for the detection of myometrial invasion was 90%, specificity 71%, positive predictive value (PPV) 93% and negative predictive value (NPV) 63%. For the detection of deep invasion, sensitivity was 56%, specificity 77%, PPV 64% and NPV 71%. All women with grade one or two tumours having no invasion or grade one having superficial invasion detected on MRI had pathological 'low risk' disease. CONCLUSIONS: Magnetic resonance imaging scans as reported offered limited clinical benefit. Attention needs to be given to MRI sequencing and reporting protocols. If the review results can be confirmed by prospective studies, MRI offers significant clinical utility in the identification of low risk patients and their surgical treatment planning.