Effect and rational application of topical photodynamic therapy (PDT) with 5-aminolevulinic acid (5-ALA) for treatment of cervical intraepithelial neoplasia with vaginal intraepithelial neoplasia

Background: Lesions in both the cervix and vagina require an efficacious non-invasive treatment therapy such as 5-Aminolevulinic acid photodynamic therapy(5-ALA-PDT). In this study, we evaluate clinical efficacy and safety of 5-ALA PDT for cervical intraepithelial neoplasia with vaginal intraepithelial neoplasia (CIN & VAIN).

Methods: A retrospective analysis was performed on 48 patients diagnosed with CIN & VAIN and receiving 5-ALA PDT. All patients were first followed up at 3, 6 and 12 months after treatment, then every 6 months thereafter.

Results: Out of 1051 patients referred for CIN (4.56%), 48 were diagnosed with CIN&VAIIN. The patients had statistically significant average vaginal and cervical lesion areas of 1.22 and 0.41 cm² respectively. 4 patients were lost during follow-up. The patients' complete remission (CR) rate was 88.64% (39/44) at 3-6 months after treatment, while the total HPV clearance rate was 46.34 and 60.98% at 3- and 12-months follow-up,respectively. HPV16/18 combined with other high-risk human papillomaviruses (hrHPV) (HPV16/18 and other hrHPV) infection exhibited a lower HPV clearance rate (P = 0.006). The treatment time in high-grade intraepithelial neoplasia (HSIL) was higher than that of low-grade intraepithelial neoplasia (LSIL). Notably, atypical vessels and endocervical canal lesions involvement significantly affected 5-ALA PDT. Moreover, 5 patients had residual lesions (11.36%) during follow-up, one patient presented recurrence (2.56%), while 4 had successful pregnancy.

Conclusions: 5-ALA-PDT is a non-invasive, effective, and safe therapy for treating CIN & VAIN and can maintain the structural and functional integrity of target organs. However, its efficacy is relatively poor in patients with endocervical canal lesions involvement, atypical vessels, and HPV16/18 and other hrHPV infection.