Literature Review of Vaginal Stenosis and Dilator Use in Radiation Oncology

Abstract

Purpose: Guidelines for the care of women undergoing pelvic radiation therapy (RT) recommend vaginal dilator therapy (VDT) to prevent radiation-induced vaginal stenosis (VS); however, no standard protocol exists. This review seeks to update our current state of knowledge concerning VS and VDT in radiation oncology.

Methods and materials: A comprehensive literature review (1972-2017) was conducted using search terms "vaginal stenosis," "radiation," and "vaginal dilator." Information was organized by key concepts including VS definition, time course, pathophysiology, risk factors, and interventions.

Results: VS is a well-described consequence of pelvic RT, with early manifestations and late changes evolving over several years. Strong risk factors for VS include RT dose and volume of vagina irradiated. Resultant vaginal changes can interfere with sexual function and correlational studies support the use of preventive VDT. The complexity of factors that drive noncompliance with VDT is well recognized. There are no prospective data to guide optimal duration of VDT, and the consistency with which radiation oncologists monitor VS and manage its consequences is unknown.

Conclusions: This review provides information concerning VS definition, pathophysiology, and risk factors and identifies domains of VDT practice that are understudied. Prospective efforts to monitor and measure outcomes of patients who are prescribed VDT are needed to guide practice.

Figure 1:

MRI pelvis T2 sagittal images from a post-menopausal female with locally advanced cervical cancer pre- (A) and post- (B) definitive brachytherapy. She was not sexually active and she was compliant with dilators for only 6 months after completing her treatments. Her pelvic exam at 3 years post radiotherapy was remarkable for atrophic changes, an agglutinated vagina, and a cervix which could not be identified on visualization. On palpation, the parametria were not infiltrated and the rectovaginal septum was supple. Her pre-brachytherapy image with vaginal gel delineating the walls of the vagina is shown on the left (A). Her post treatment image with the same sequence performed 3 years later, on the right (B), shows uterine atrophy and closure of the upper 2/3 of the vaginal wall (black arrows) - a clear depiction of the grade 3 vaginal stenosis described by physical exam- and no evidence of disease.

Figure 2:

MRI pelvis T2 sagittal images with vaginal gel illustrating vaginal shortening secondary to adhesion formation following definitive chemoradiation and brachytherapy in 2 different post-menopausal patients treated for stage II vaginal cancer. Moderate changes occluding the upper ½ of the vagina on the right (B) compared to mild-to-no changes on the left (A).

Figure 3:

Sagittal (A) and coronal (B) T2-weighted MRI images of an irradiated vagina with vaginal gel in a pre-menopausal female who was NED 7 months following chemoradiation and vaginal brachytherapy boost to the upper half of the vaginal canal. The arrows point to thickening due to irradiation in the upper ½ of the vaginal wall, with resulting narrowing of the vaginal apex.