Evaluation of three-dimensional ultrasound measurement techniques used to assesses myometrial invasion in endometrial cancer

Purpose: To assess interobserver variation and efficiency of various measurements on 3-dimensional transvaginal ultrasound (3D-TVS) and saline infusion sonography (3D-SIS) for preoperative measurement of deep myometrial invasion (DMI) in endometrial cancer. Materials and Methods: One hundred ten women with atypical endometrial hyperplasia or endometrial adenocarcinoma had preoperative 3D-TVS and 3D-SIS. Endometrial thickness (ET), ET in percent of uterine diameter (PAP) and various volumes were measured. AUC, sensitivity, and specificity of most optimal cut-points, and kappa statistics for observer variation were calculated. Results: PAP identified two-thirds of women with DMI. ET and 3D volume measurements had substantial observer agreement compared to moderate agreement of subjective evaluation of DMI. AUC for measurements ranged 0.63-0.73 for identification of DMI. Subjective evaluation of DMI had highest AUC only marginally improved by adding PAP. Conclusion: Preoperative staging of endometrial cancer is not improved by adding 3D volume measurements to subjective evaluation, but PAP could be used to select women with a high risk of DMI for further MRI.