Efficacy and safety of photodynamic therapy mediatied by 5-aminolevulinic acid for the treatment of vaginal high-grade intraepithelial lesions.

Background: Vaginal high-grade squamous intraepithelial lesion (HSIL) (vaginal intraepithelial neoplasia [VAIN] grade 2-3) is clinically, a precancerous lesion condition with an estimated progression rate of 10%-20%. Therefore, treatment is recommended. Because traditional treatments have limited effects, high expense and complications, here we evaluated the efficacy and safety of topical 5-aminolevulinic acid (ALA)-based photodynamic therapy (PDT).

Methods: This study consisted of 56 female patients diagnosed with vaginal HSIL. A 20% 5-ALA jelly formation was topically applied to the vaginal wall, followed by 635 nm PDT at 7-14 days intervals. Cytology, human papillomavirus (HPV) genotyping, colposcopy, and pathology were assessed after treatment.

Results: Among the 56 patients in our study, 47 (83.9%) had VAIN 2 and 9 (16.1%) had VAIN 3. 35 patients underwent three courses of PDT treatment, 19 experienced six courses, and two experienced nine courses. The total pathological regression rate was 87.5%, and the HPV clearance rate during the 6-month follow-up was 41.9%. Lesions located in the vaginal stump after hysterectomy seem to be difficult to treat. 9%(4/44) and 23%(7/30) patients had recurrent disease during the 6-month and 1-year follow-up time point. The most common adverse event was increased vaginal discharge, other side effects include abdominal pain, vulvar pruritus, and vaginal bleeding. No severe adverse effect was observed during the treatment.

Conclusion: Photodynamic therapy mediatied by 5-aminolevulinic acid is an effective and safe treatment for vaginal HSIL with minimal side effects.