ABSTRACT
Photodynamic therapy (PDT) is a simple, minimally invasive treatment modality. It is also known as photoradiation therapy/phototherapy. Photodynamic therapy became more popular when international photodynamic association was formed by Thomas Dougherty in the year 1986. For the first time, it was used in dermatology in the year 1992, later in oncology (1995), microbiology since the year 1996 and itis also been used in dentistry. Three components namely light source, photosensitising agent and oxygen are utilised, which individually are harmless by itself, but when combined with oxygen they produce cytotoxic agents that have the ability to inactivate the tumour cells. This enables the selectivity of the diseased tissue. Main advantages of PDT are as follows: it is cost-effective, can be performed on out-patient basis and tissue heals by little or no scarring. PDT can be used in the treatment of actinic keratosis, Bowen's disease, superficial squamous cell carcinoma, and so on. Uses of PDT are increasing day by day and even nowadays research is going on to make use of nanoparticles in PDT to make it a more promising treatment approach.