Objective  To study the effect of 5-aminolaevulinic acid-based photodynamic therapy (ALA-PDT) for human papillomavirus (HPV) infection combined with cervical intraepithelial neoplasia (CIN).

  Methods  A total of 100 patients with cervical intraepithelial neoplasia diagnosed by colposcopy and pathological examination were selected as the study subjects, and were randomly divided into placebo group, 5% ALA treatment group, 10% ALA treatment group, and 20% ALA treatment group, with 25 in each group, given placebo, ALA thermosensitive gel in concentration s of 5%, 10% and 20%, respectively. At 3 and 6 months after treatment, the cervical condition of the patients was examined by the results of histology and cytology, and the negative rate of DNA was compared. At the same time, the adverse reactions of the patients were recorded and analyzed.

  Results  After 3, 6 months of treatment, there were no significant differences in the efficacy between placebo group and 5% ALA group, 10% ALA group and 20% ALA group (P>0.05). After 3 months of treatment, the effective rate of CINⅡ patients in placebo group was significantly lower than that in 20% ALA group, difference was found in two groups (P < 0.05). The negative conversion rate of HPV16/18 in 20% ALA group was significantly higher than that in placebo group, 5% ALA group and 10% ALA group after 6 months of treatment (P < 0.05).

  Conclusion  20% ALA has higher efficiency and negative conversion rate in the treatment of CINⅡ patients, which has a good prospect in the treatment of CIN patients with HR-HPV infection.