Efficacy of 5-aminolevulinic acid and LED photodynamic therapy in cervical intraepithelial neoplasia: A clinical trial
5-Aminolaevulinic acid (5ALA) is a precursor of the strong sensitizer protoporphyrin IX (PpIX) in the heme synthesis pathway. We conducted aclinical trial designed to evaluate the efficacy and safety of 5ALA photodynamic therapy (PDT) using a light-emitting diode (LED) in patients with cervical intraepithelial neoplasia (CIN). Data for 51 CIN patients who underwent 5ALA-PDT between 2012 and 2017 were prospectively analysed. After a 20 % 5ALA jelly formulation was topically applied to the cervix, the region was irradiated with red light at approximately 633 nm to excite PpIX for treatment. We estimated outcomes by cytology, pathology, and human papilloma virus (HPV) testing after PDT. Patients underwent two PDT sessions at one-week intervals during outpatient treatment and achieved favourable results without photosensitivity and severe adverse events. Over a long follow-up period, 96.1 % of all patients showed some positive effects, including approximately 70 % with a complete response (CR), 10 % with a partial response, and 15 % with downgrades. The HPV clearance rate in patients with CR was 79.4 %. Recurrence occurred in five patients who mostly remained HPV-positive after PDT. Based on our study, topical 5ALA-PDT using an LED light source potentially represents a safe treatment for CIN on an outpatient basis.