Comparative efficacy of topical 5-aminolevulinic acid versus Hiporfin photodynamic therapy in HPV-positive cervical intraepithelial neoplasia grade II

Abstract

Objective: Given the global trend of delayed childbearing, the feasibility of non-surgical treatments-such as photodynamic therapy and conservative management-for CIN II has become an area of increasing research interest. Photodynamic therapy can be administered either systemically or locally; however, there remains a lack of consensus regarding its optimal clinical application. Based on rigorous patient selection, comprehensive informed consent, and a structured follow-up protocol, this study aims to evaluate and compare the therapeutic efficacy of different photodynamic therapy modalities and conservative treatment in patients with CIN II, thereby providing evidence-based guidance for individualized clinical management.

Methods: A retrospective analysis was carried out on 111 patients with CIN2 at Peking University Shenzhen Hospital and Zhujiang Hospital of Southern Medical University from October 2019 to December 2024. According to the inclusion and exclusion criteria, 46 patients were treated with ALA-PDT,32 with HPF-PDT, and 33 were assigned to the follow-up observation group. In the first month post-PDT treatment, two groups were followed up. All three groups were followed up during the 3rd to 5th months and the 6th to 12th months. Key evaluation metrics included the effectiveness of cervical lesion treatment and the rate of HR-HPV infection clearance.

Results: At the first month follow-up, three patients in the HPF-PDT group exhibited allergic reactions. At the 3rd to 5th months follow-up, three patients in the HPF-PDT group were found to have cervical canal adhesions. The efficacy rates following ALA-PDT at 3rd-5th months and 6th-12th months were 93.0% (40/43) and 100% (27/27), compared to 90.3% (28/31) and 95.7% (22/23) after HPF-PDT.HPV clearance rates following ALA-PDT at 3rd-5th and 6th-12th months were 58.7% (27/46) and 77.8% (21/27) compared to 46.9%(15/32) and 62.5% (15/24) after HPF-PDT, with no significant difference between the two groups (P = 0.675 at 3rd-5th months, P = 0.274 at 6th-12th months; P = 0.303 and P = 0.705, respectively). Both rates were significantly higher than those of the observation group (39.4% (13/33) and 62.1% (18/29), P < 0.0001 and P < 0.0001; 6.1% (2/33) and 10.3% (3/29), P < 0.0001 and P < 0.0001). Due to follow-up discontinuation for some patients from June to December, a sensitivity analysis using March-May data yielded consistent results.

Conclusions: While both ALA-PDT and HPF-PDT demonstrate comparable and high efficacy for CIN2, their risk-benefit profiles are distinct. HPF-PDT is associated with a clinically significant risk of cervical adhesions and potentially burdensome, prolonged systemic photosensitivity. Therefore, for patients without endocervical involvement, ALA-PDT presents a superior safety profile and should be considered the preferred PDT modality. The role of HPF-PDT should be carefully re-evaluated and likely reserved for select cases where lesion location justifies its additional risks. Conservative management remains a viable option with a high regression rate under close surveillance.

Keywords: 5-aminolevulinic acid photodynamic therapy; Cervical intraepithelial neoplasia grade 2; Hiporfin photodynamic therapy; Human papillomavirus infection.