The history of photodetection and photodynamic therapy

Light has been employed in the treatment of disease since antiquity. Many a ncient civilizations utilized phototherapy, but it was not until early last century that this form of therapy reappeared. Following the scientific dis coveries by early pioneers such as Finsen, Raab and Von Tappeiner, the comb ination of light and drug administration led to the emergence of photochemo therapy as a therapeutic tool. The isolation of porphyrins and the subseque nt discovery of their tumor-localizing properties and phototoxic effects on tumor tissue led to the development of modern photodetection (PD) and phot odynamic therapy (PDT). This review traces the origins and development of P D and PDT from antiquity to the present day.