Toluidine Blue and Chlorin-e6 Mediated Photodynamic Therapy in the Treatment of Oral Potentially Malignant Disorders: A Systematic Review

Abstract

Oral potentially malignant disorders (OPMDs) are conditions that carry an increased risk of malignant transformation, including oral leukoplakia and oral lichen planus. Current management approaches differ based on each condition’s unique etiology and pathophysiology, but all available treatment methods have notable limitations. This has prompted continued efforts to identify more effective therapeutic options. Photodynamic therapy (PDT) has emerged as a minimally invasive yet potent alternative for treating OPMDs. This systematic review examines the efficacy of PDT mediated by toluidine blue and chlorin-e6 (Photolon) in managing OPMDs. Following the PRISMA guidelines, eight relevant studies published between 2010 and 2024 were included. Data on the study design, protocols, light parameters, and photosensitizer characteristics were collected to evaluate treatment outcomes. The reviewed evidence suggests that toluidine-blue- and chlorin-e6-mediated PDT holds promise as a minimally invasive treatment modality for OPMDs, especially for oral lichen planus and oral leukoplakia. Studies indicate its potential as an alternative or adjunct therapy, particularly for symptomatic or refractory oral lichen planus. However, discrepancies in study designs and treatment protocols, coupled with the limited number of trials, impeded direct comparisons. Toluidine-blue- and chlorin-e6-mediated PDT shows significant potential as a therapeutic option for OPMDs. Nonetheless, further investigations—including large-scale randomized controlled trials, standardized treatment guidelines, and the exploration of additional OPMDs beyond oral lichen planus and oral leukoplakia—are necessary in order to fully establish its clinical utility and facilitate widespread adoption.