[Lasers in medicine]

Laser systems are widely spread in the field of medicine. The applications are divided into therapeutical and diagnostic applications. The main field however are therapeutical procedures. Depending on the indication lasers were used for removing and cutting of smooth and hard tissue or for coagulation. A relative new procedure is the photodynamic therapy. Substances--mostly dyes--are applied to the body and stay for a certain time in tumorous tissue. After an interval it is possible to irradiate this tissue. Only the cells with the incorporated substances react with a cell death.