Review of the role played by the photosensitizer's photobleaching during photodynamic therapy

摘要

Photodynamic therapy (PDT) is based on the combined administration of photosensitizing drugs and light to treat a variety of malignant, pre-malignant and also non-malignant diseases. The reactive species resulting from the excitation of the photosensitizers are at the origin of their photodegradation, which has an influence on the treatment outcome. PDT has a long history, including the improvements of photosensitizers and light delivery systems, which led to approved clinical applications. A knowledge of the photobleaching processes occurring during PDT will help implicit dosimetry, as it describes multiple photophysical, photochemical and photobiological factors involved in PDT. Due to this the clinical efficacy of PDT and optimisation of treatment regimes will be allowed.