Since the patients suffering from female lower genital tract diseases are getting younger and younger and the human papilloma virus (HPV) infection is becoming more widespread, the novel non-invasive precise modalities of diagnosis and therapy are required to remain structures of the organ and tissue, and fertility as well, by which the less damage to normal tissue and fewer adverse effects are able to be achieved. In all nucleated mammalian cells, 5-Aminolevulinic acid (5-ALA) is an amino acid that occurs spontaneously, which further synthesizes in the heme biosynthetic pathway into protoporphyrin IX (PpIX) as a porphyrin precursor and photosensitizing agent. Exogenous 5-ALA avoids the rate-limiting step in the process, causing PpIX buildup in tumor tissues. This tumor-selective PpIX distribution after 5-ALA application has been used successfully for tumor photodynamic diagnosis (PDD) and photodynamic therapy (PDT). Several ALA-based drugs have been used for ALA-PDD and ALA-PDT in treating many (pre)cancerous diseases, including the female lower genital tract diseases, yet the ALA-induced fluorescent theranostics is needed to be explored further. In this paper, we are going to review the studies of the mechanisms and applications mainly on ALA-mediated photodynamic reactions and its effectiveness in treating female lower genital tract diseases.

BACKGROUND: With the younger onset age of female lower genital tract diseases, there are increasing demands for protecting organ and tissue structures to preserve fertility and, therefore, effective fertility-sparing treatments that cause minimal normal tissue damage and less adverse reactions are urgently needed.
OBJECTIVE: This study is aimed at reviewing information and achieving consensus on recommendations on the clinical applications of aminolevulinic acid-based photodynamic therapy (ALA-PDT) in female lower genital tract diseases.
METHODS: Members of the expert panel held online and in-person meetings to discuss and revise drafts created by the steering committee based on the literature review and the clinical experiences of the expert panel. Opinions of the experts were transcribed and discussed in detail to ensure that the consensus statement best reflects the current advances in the field and the experts\' view.
RESULTS: After numerous rounds of meetings, experts unanimously agreed on the importance of ALA-PDT in the treatment of cervical squamous intraepithelial lesions (SIL), vaginal SIL, vulvar SIL, vulvar lichen sclerosus (VLS), and condyloma acuminatumon (CA). Experts also reached consensus on the recommended treatment regimen and treatment methods.
CONCLUSIONS: This consensus aimed to provide practical basis and guidance for the clinical applications of ALA-PDT in female lower genital tract diseases in China. Of note, this is the only expert consensus prepared by board-certified specialists in gynecology and obstetrics in China. More evidence-based clinical studies should be made to update and expand the current recommendations.