1.What is photodynamic therapy? Ala photodynamic therapy (ALA-PDT) is a treatment method that uses photosensitizers to produce cytotoxic substances under the irradiation of specific wavelengths of visible light to destroy target tissues and cells to treat diseases. 2.What are the factors related to the occurrence of cervical cancer? The 2008 Nobel Prize winner in physiology or medicine – German scientist Harald? Trull? Hausen spent more than a decade studying the relationship between viruses such as human papillomavirus (HPV) and cervical cancer and found that certain types of HPV are the causative agent of cervical cancer. Persistent HPV infection is the most critical factor in the development of cervical cancer. 3.How to prevent the occurrence of cervical cancer? Early intervention to clear HPV infection can effectively prevent the occurrence of cervical cancer. It has been proven that without high-risk HPV infection, no high-risk CIN (cervical epithelial neoplasia) lesions occur. with the clearance of high-risk HPV, CIN lesions will change from high to low. after the HPV turns negative, the original medium to high level lesions can recover within 32 months on average. 4. Has ALA-PDT been shown to be effective in treating cervical HPV infection? In 105 foreign patients with cervical CIN treated with ALA-PDT and followed up at month 3 and month 6, the cure rate reached 90% and 98%, and the HPV regression rate was 74% and 73%, respectively. From 2006 to 2007, more than 70 patients with cervical lesions combined with HPV infection received a course of two ALA-PDT treatments and were followed up at 3 months. 85% of the patients were HPV negative (HC-II test). 5. Has ALA-PDT been approved for the interventional treatment of cervical-related diseases with co-infection with HPV? In September 2008, the Shanghai Municipal Health Bureau approved ALA-PDT for the treatment of gynecologic-related diseases and interventional treatment of cervical diseases with co-infection with HPV, mainly for the following related diseases: for the treatment of patients who are positive for high-risk HPV and have been persistently infected for more than one year. For the treatment of high-risk HPV-positive patients with cervical CIN I. For the treatment of high-risk HPV positive patients with viral load above 100 pg/mL and other associated cervical symptoms. 6.Is ALA-PDT treatment safe? ALA-PDT is very safe for the treatment of HPV infection, with no bleeding, no anesthesia, selective destruction of diseased tissue, preservation of normal cervical tissue structure, no impact on the patient’s reproductive function, repeatable treatment, fast drug metabolism, no phototoxicity, no need to avoid light.