The diagnostic accuracy of 3D ultrasound compared to 2D ultrasound and MRI in the assessment of deep myometrial invasion in endometrial cancer patients: A systematic review.

Endometrial cancer is a common malignancy in women worldwide, with myometrial invasion (MI) being an important prognostic factor, usually assessed via imaging techniques. The aim of this review is to compare the diagnostic accuracy of 3D transvaginal ultrasound (3D-TVUS), a relatively new imaging modality, to that of 2D transvaginal ultrasound (2D-TVUS) and MRI in the prediction of deep myometrial invasion. Relevant articles were sought on MEDLINE/PubMed, Scopus, Web of Science and Wiley Online Library databases. Articles were included if they were primary studies comparing 3D-TVUS to 2D-TVUS and/or MRI in adult endometrial cancer patients, with histopathological confirmation of MI as a reference standard. Ultimately, 7 studies were included, with 714 participants, 242 with deep MI and a mean age of approximately 60 years. 3D-TVUS, 2D-TVUS, MRI and 3D-TVUS-MRI co-evaluation had a pooled sensitivity of 80.4%, 77.6%, 80.7% and 94.6% respectively and a specificity range of 82.8%, 81.6%, 87% and 69.1% respectively. Overall, no statistically significant differences were found in sensitivity and specificity among 3D-TVUS and the other methods, except for a significant increase in sensitivity (p = 0.038) when combined with MRI. This shows that 3D-TVUS is comparable to MRI as far as diagnostic accuracy is concerned, however remains cheaper, less time-consuming and more tolerable, while offering some advantages over 2D-TVUS as well. Therefore 3D-TVUS application in MI assessment seems promising, although more research is required to further assess this finding and ascertain 3D-TVUS's place in endometrial cancer MI assessment.