Rational of topical photodynamic therapy (PDT) with 5-aminolevulinic acid (5-ALA) for treatment of endocervical canal low-grade squamous intraepithelial lesion with high-risk human papillomavirus infection

Abstract

Background: The detection and continuous monitoring of low-grade squamous intraepithelial lesions (LSIL) within the endocervical canal pose considerable challenges, and the effectiveness of ablation treatment is also constrained. In this context, the potential efficacy of 5-aminolevulinic acid photodynamic therapy (5-ALA PDT) in targeting these concealed lesions merits exploration. The present study undertakes a comprehensive analysis of the clinical effectiveness and safety aspects associated with the utilization of 5-ALA PDT.

Methods: A retrospective analysis was conducted on a cohort of 13 patients who were diagnosed with LSIL within the endocervical canal, concomitant with high-risk human papillomavirus (hrHPV) infection. These patients were subjected to treatment with 5-ALA PDT and subsequently monitored over a period of 3-6 months following the intervention.

Results: The study cohort comprised 13 patients, among whom 4 presented with isolated lesions within the endocervical canal, 5 exhibited LSIL involving both the endocervical canal and the cervix vaginal portion, 3 displayed LSIL within the endocervical canal in conjunction with vaginal involvement, and 1 patient demonstrated lesions across all three of these anatomical sites. All identified lesions underwent therapeutic intervention via 5-ALA PDT. Before treatment initiation, 9 patients returned positive results in the liquid-based cytologic test (LBC), 4 displayed concurrent multiple hrHPV infections, and 5 manifested infections specifically with HPV 16/18. Subsequent to the application of 5-ALA PDT, regression was observed in the LBC results of all patients, with only 3 individuals retaining a singular type of hrHPV infection. Adverse reactions following treatment encompassed mild aberrant vaginal secretions and mild to moderately pronounced distending abdominal discomfort, all of which were remitted within a span of 7 days.

Conclusions: Within the context of LSIL within the endocervical canal in association with hrHPV infection, the findings affirm the efficacy and safety of 5-ALA PDT as a viable therapeutic modality.

Keywords: 5-aminolevulinic acid photodynamic therapy; endocervical canal; human papillomavirus; low-grade squamous intraepithelial lesion.