Contrast vaginography is more accurate than the radiopaque rod for localization of the vagina

Purpose: To compare the radiopaque vaginal rod method with contrast vaginography in localization of the vagina. Methods and Materials: In 25 female patients who needed pelvic radiotherapy, both our standard localization procedure using the vaginal rod and a localization procedure using contrast vaginography were performed. As a rod can change the position of the vagina, contrast vaginography was considered to display the true anatomic position of the vagina. The corresponding rod and nonrod X-rays of each patient were compared. The distance from the true vaginal apex to the displaced vaginal apex (= the top of the rod) was measured in the sagittal plane. This distance was called the inaccuracy of the rod method. Furthermore, the size of the vaginal vault was measured using the contrast vaginography. Results: The median inaccuracy of the rod method was 13 mm (range 2 to 24 mm). The maximal width of the vagina ranged from 24 to 68 mm in the frontal plane (median 39 mm) and from 3 to 22 mm in the sagittal plane (median 10 mm). Conclusion: The rod method is not accurate to localize the vagina. Furthermore, the rod gives no information on the actual size of the vaginal vault. Contrast vaginography is the method of choice to localize the vagina.