This multicenter, prospective trial assesses ALA-PDT versus observation for efficacy and safety in treating cervical LSIL with HPV16/18 infection.

This study is a multicenter, prospective, concurrent, non-randomized controlled clinical trial designed to evaluate the clinical efficacy of ALA-PDT treatment compared with observation and follow-up in patients with cervical low-grade squamous intraepithelial lesion (LSIL) associated with HPV16/18 infection. The primary outcome is the cervical lesion reversal rate. Secondary outcomes include HPV16/18 clearance rate and time to clearance, as well as improvements in cervical ectropion and vaginal microenvironment. Additionally, lesion progression rate and recurrence rate will be monitored in both groups. Safety, tolerability, patient-reported quality of life, and treatment satisfaction are also assessed.

Inclusion Criteria:

1. Female, 20-60 years, understands study procedures and consents to participate;
2. HPV 16 or 18 positive;
3. Colposcopy-guided cervical biopsy within 3 months showing LSIL;
4. Provides written informed consent.

Exclusion Criteria:

1. Cytology showing ASC-H, HSIL, AGC, or AIS; or evidence of malignant cells on cytology/histology, or suspicion of malignancy or invasive cancer;
2. Colposcopy findings suggestive of invasive cancer or lesion extension to the vaginal wall;
3. Severe pelvic, cervical, or other gynecological inflammatory conditions identified clinically;
4. Undiagnosed vaginal bleeding;
5. Active allergic disease, porphyria, or history of allergy to the study drug or structurally similar agents;
6. Severe cardiovascular, neurological, psychiatric, endocrine, hepatic, or hematologic disorders; known immunodeficiency; long-term glucocorticoid or immunosuppressant use; active autoimmune disease; or other malignancies;
7. Pregnant or breastfeeding women;
8. History of hysterectomy, cervical cancer treatment, or cervical excision/ablation within 6 months (e.g., conization, LEEP, laser);
9. Use of interferon or antiviral therapy within 3 months;
10. Any other condition deemed unsuitable for participation by the investigator.