Table 1—

Evolution of photodynamic therapy and definition of treatments involving light

HeliotherapyUse of sunlight for treatment
PhototherapyTreatment using specific light (e.g. ultraviolet)
PhotochemotherapyTreatment using specific light and chemical compound, and nonspecific light, usually in the presence of air/oxygen
Photodynamic therapyTreatment using chemical photosensitising agent (drug)
+ matching specific wavelength light (laser/nonlaser, i.e. collimated/noncollimated light)
+ oxygen (present in living tissue environment)