Assessment of myometrial invasion in endometrial cancer using three-dimensional ultrasound and magnetic resonance imaging.

INTRODUCTION: Preoperative knowledge of myometrial invasion in endometrial cancer is important for surgical planning. This study aimed to assess the diagnostic efficiency of two-dimensional (2D) and three-dimensional (3D) transvaginal ultrasonography (TVS) with and without saline infusion (SIS) and magnetic resonance imaging (MRI) for assessment of myometrial invasion in endometrial cancer.

MATERIAL AND METHODS: 110 women with atypical endometrial hyperplasia or endometrial adenocarcinoma underwent preoperative 2D- and 3D-TVS with and without SIS and MRI. Offline 3D-TVS measurement was performed of the minimal tumor-free margin in relation to myometrial thickness expressed as deep (≥ 50%) myometrial invasion and subjective impression of cervix involvement. The quality of images was also evaluated. Diagnostic efficiencies were calculated for myometrial and cervical involvement for each method. The pathologist's final diagnosis served as the reference standard.

RESULTS: For myometrial involvement, MRI showed greater accuracy than 3D-TVS or 2D-TVS (83, 71 and 75%, respectively). The efficiency of 3D-TVS was not superior to 2D-TVS and did not improve with SIS. The sensitivities of 2D-TVS and 3D-TVS were similar to that of MRI, and the efficiency of 3D-TVS improved when volumes of inadequate quality (39%) were excluded. For evaluating cervical involvement, the accuracy of 3D-TVS was 85%, comparable to the results of 2D-TVS (80%) and MRI (85%). The results did not improve when saline was added.

CONCLUSION: 3D-TVS or 3D-SIS was not more efficient than 2D-TVS or MRI for assessment of myometrial invasion in endometrial cancer. 3D-TVS assessment without 2D-TVS was impeded by difficulties in obtaining 3D-TVS volumes of sufficient quality.