709 TVS Vs MRI for assessing myometrial infiltration in endometrioid low grade endometrial cancer: a prospective study

Abstract

<h3>Introduction/Background*</h3> Determining the degree of myometrial infiltration in endometrial cancer allows establishing the best therapeutic approach for each patient as it is an important factor in predicting nodal metastases. Few prospective studies comparing the diagnostic performance of transvaginal ultrasound (TVS) and magnetic resonance imaging (MRI) in the preoperative local staging of endometrial carcinoma have been reported. In fact, a recent meta-analysis has shown that both techniques have similar diagnostic accuracy. However, to the best of our knowledge, there has been no prospective comparison of the diagnostic performance of TVS and MRI in the same group of patients with low-grade endometrial cancer. The aim of this study was to assess and compare the diagnostic performance of transvaginal ultrasound, magnetic resonance imaging (MRI) and intraoperative pathological study for detecting deep myometrial infiltration in patients with a preoperative endometrial biopsy result of low-grade (G1/G2) endometrioid endometrial cancer. <h3>Methodology</h3> Observational prospective study performed at a single tertiary care centre from 2016 to 2020, comprising 156 consecutive patients diagnosed by endometrial sampling as having an endometrioid grade 1/grade2 endometrial cancer. TVS and MRI were performed prior to surgical staging for assessing MI, which was estimated using subjective examiner’s impression and Karlsson’s method for both TVS and MRI. During surgery, intraoperative assessment of MI was also performed. Definitive pathological study considered as reference standard. Diagnostic accuracy for ultrasound, MRI and intraoperative biopsy was estimated and compared. <h3>Result(s)*</h3> Sensitivity and specificity of TVS for detecting deep MI were 75% and 73.5% for subjective impression and 65% and 70% for Karlsson method, respectively (p=0.54). Sensitivity and specificity of MRI for detecting deep MI were 80% and 87% for subjective impression and 70% and 71.3% for Karlsson method. MRI subjective impression showed a significant better specificity than MRI Karlsson method (p=0.03). MRI showed better specificity than TVS when subjective impression was considered (p&lt; 0.05), but not for Karlsson method. Sensitivity and specificity of intraoperative were 75% and 97%, respectively. Intraoperative biopsy showed better specificity than ultrasound and MRI either using examiner’s impression or Karlsson method (p&lt; 0.05) <h3>Conclusion*</h3> MRI revealed a significant higher specificity than TVS when assessing deep myometrial infiltration. However, the intraoperative biopsy offers a significant better diagnostic accuracy than preoperative imaging techniques