Efficacy of photodynamic therapy for cervical intraepithelial neoplasia grade 3: a retrospective study

This study aimed to evaluate the histologic response rate of high-grade squamous intraepithelial lesion (HSIL), also referred to as cervical intraepithelial neoplasia 3 (CIN 3), following treatment with 5-aminolevulinic acid photodynamic therapy (ALA-PDT).

A retrospective analysis was conducted on 49 patients diagnosed with CIN 3 and treated with ALA-PDT between March 2022 and December 2024. Patients received either ALA-PDT alone or in combination with the Loop Electrosurgical Excision Procedure (LEEP) or CO₂ laser therapy. Clinical outcomes, including human papillomavirus (HPV) status, cytology, and histology, were assessed over a 12-month follow-up period.

Among the 44 patients with complete follow-up, the total response rate was 85.19% (23/27) for ALA-PDT alone and 88.24% (15/17) for combination therapy, yielding an overall response rate of 86.36% (38/44). The double-negative rate (negative for both HPV and histopathology) was 100%. When stratified by age group, pathology-negative outcomes-considered effective treatment responses-were observed in 100% of patients younger than 20, 80% of those aged 21-30, 93.7% in the 31-40 age group, and 100% in patients over 40. The total effective rates across different cervical transformation zones (TZ) were 75% (18/24) for TZ1, 100% (12/12) for TZ2, and 100% (8/8) for TZ3. Negative HPV conversion rates were 82.35% (28/34) in the HPV16/18-positive group, 80% (8/10) in the non-HPV16/18 group, and 73.33% (11/15) in the multiple high-risk HPV group.

ALA-PDT demonstrates favorable efficacy and stability in patients with HSIL/CIN 3, offering clinicians an additional option for managing these cervical lesions.