[One hundred years of radiotherapy. Historical origins and development of fractionated irradiation in German speaking countries].

This review studies the historical development of fractionated X-ray therapy in the German speaking countries until World War II. Fractionated treatments appear to have their origin already in the first attempts of fractionation performed by Freund in 1896. In the following, fractionated treatments could not compete with the so-called single dose or intensive radiation treatment in Germany. However, until the 1920s there were repeated sporadic attempts of various motifs to distribute the radiation doses over a prolonged period of time. Only with the end of the 1920s the conditions for a rise of fractionated irradiation were favourable, mainly due the fiasco of the intensive treatments and their subsequent decline. The impulse for this rise, however, came from France where Coutard had developed an individual empirical treatment regimen with great clinical success. This technique and its modifications and developments spread over Europe and America fast. In spite of the similarities between the various fractionation methods used during the first decades of the century, review of the radiological literature of that time fails to show any logical scientific connection of these methods, but rather there was a mix and overlap of irradiation attempts of various motivations. Thus, radiation therapy, and thereby the current standard fractionation scheme of 1.8 to 2 Gy per fraction 5 times per week, obviously did not grow out of a scientific basis, but originated from individual observation of patients and empirical experience.