Transvaginal ultrasound for preoperative assessment of myometrial invasion in patients with endometrial cancer: a systematic review and meta-analysis.

OBJECTIVE: To review the diagnostic accuracy of transvaginal ultrasound (TVS) in the preoperative detection of deep myometrial infiltration in patients with endometrial cancer, comparing subjective and objective methods. METHODS: An extensive search was performed in MEDLINE (PubMed) and EMBASE for studies published between January 1989 and December 2014. The eligibility criterion was use of TVS for preoperative assessment of myometrial infiltration by subjective evaluation and/or objective measurements. Objective measurements included, specifically, the approaches of Gordon (ratio of the distance between endometrium-myometrium interface and maximum tumor depth to the total myometrial thickness) and Karlsson (endometrial tumor thickness/anteroposterior uterine diameter ratio), in women with endometrial cancer, using the surgical pathological data as a reference standard. Study quality was assessed using the QUADAS-2 tool. RESULTS: Our extended search identified a total of 184 citations, among which we examined the full text of 24 articles. Overall pooled sensitivity, specificity, positive likelihood ratio (LR+) and negative likelihood ratio (LR-) of TVS for detecting deep myometrial infiltration were 82% (95% CI, 76-87%), 81% (95% CI, 76-85%), 4.3 (95% CI, 3.6-5.3) and 0.22 (95% CI, 0.16-0.30), respectively. We did not observe differences among the three methods in terms of diagnostic performance. Significant heterogeneity was found for sensitivity and specificity of all three methods (I(2) range, 60.6-95.0). The main limitation was that very few studies compared different approaches in the same set of patients. CONCLUSION: Diagnostic performance of TVS for detecting deep myometrial infiltration in women with endometrial cancer is moderate.