photodynamic therapy: a strong tool to battle against cancer

Cancer remains a worldwide health problem, being the disease with the highest impact on ‎global health. even with all the recent technological improvements, recurrence and ‎metastasis still are the main cause of death. since photodynamic therapy (pdt) does not ‎compromise other treatment options and presents reduced long-term morbidity when ‎compared with chemotherapy or radiotherapy, it appears as a promising alternative ‎treatment for controlling malignant diseases. pdt involves administering a photosensitizing ‎dye, i.e. photosensitizer that selectively accumulates in tumors, and shining a light source on ‎the lesion with a wavelength matching the absorption spectrum of the photosensitizer, that ‎exerts a cytotoxic effect after excitation. the reactive oxygen species produced during pdt ‎are responsible for the oxidation of biomolecules, which in turn cause cell death and the ‎necrosis of malignant tissue. pdt is a multi-factorial process that generally involves ‎apoptotic and autophagic death of the tumor cells, degeneration of the tumor vasculature, ‎stimulation of anti-tumor immune response, and induction of inflammatory reactions in the ‎illuminated lesion.‎