Stereotactic Body Radiation Therapy as an Alternative to Brachytherapy in Vaginal Cancer: A Case Report

Treatment for vaginal cancer not amenable to surgical excision often consists of primary chemoradiation followed by a brachytherapy (BT) boost.Cumulative dose to the high-risk clinical target volume should ideally be at least 80 Gy equivalent dose in 2 Gy fractions.BT is a critical component in the treatment of vaginal cancer, allowing high doses to be delivered to the tumor and low doses to critical structures.However, select patients may have medical comorbidities or anatomical variants that preclude the administration of BT.Here, we present a case in which a patient with vaginal cancer had an anatomical variant of her vaginal introitus at birth that was surgically corrected, which prohibited the introduction of a vaginal cylinder.Therefore, a stereotactic body radiation therapy (SBRT) boost was used as a replacement.The patient was successfully treated with an SBRT boost with no significant radiation-induced toxicity and remains tumor-free at 12 months.This case demonstrates the feasibility of an SBRT boost when BT is not possible and adds to comparable literature in other gynecologic malignancies.