**6. Conclusions**

VGS is a simple, inexpensive, widely available, and fast execution method that can complement ultrasound in particular cases. To our knowledge, this is the first study that has evaluated the diagnostic accuracy of VGS and MRI in cancer and compared it with the final histology. Our results show a good correlation between VGS and MRI in the assessment of tumor dimensions, highlighting the better performance of VGS in detecting small tumors (<2 cm) and in predicting the absence of fornix infiltration as it shows higher sensitivity.

Moreover, the acoustic windows created between the ultrasound probe and the tumor can improve the study of the echogenicity of squamous tumors and adenocarcinomas by emphasizing the hyperechogenicity of the latter. There was a very good concordance between stromal invasion predicted by VGS and histology, which is an independent factor for the risk of lymph node involvement.

However, VGS has some limitations: despite its widespread availability, it is an operator-dependent technique, and this can limit its application to centers with highly qualified examiners.

Future studies are needed to assess the use of VGS in patients with advanced tumor stages, especially the ability to correctly identify patients with vaginal spread and septal infiltration.

**Author Contributions:** A.M.V.U.: supervision, conceptualization, methodology, formal analysis, writing—original draft, visualization, supervision, writing—review and editing; I.P.: data curation, investigation, visualization, formal analysis, writing; A.D.I.: methodology, formal analysis, writing review; D.R.: statistical analysis; G.A.: methodology, formal analysis, writing; M.E.G.: data curation, investigation; E.P.P.: visualization, data curation; S.M.: data curation, methodology, investigation; D.F.: conceptualization, methodology, writing—review and editing. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

**Institutional Review Board Statement:** The study was conducted according to the guidelines of the Declaration of Helsinki and approved by the Institutional Review Board of the European Institute of Oncology (protocol code UID 2731, approved on 6 September 2021).

**Informed Consent Statement:** All patients signed a formal consent form for the use of their data for scientific purposes.

**Data Availability Statement:** Not applicable.

**Acknowledgments:** This work was partially supported by the Italian Ministry of Health with Ricerca Corrente and 5 × 1000 funds.

**Conflicts of Interest:** The authors declare that they have no conflict of interest.
