Inauguration of radiotherapy as a new scientific speciality by Leopold Freund 100 years ago.

There is an increasing acceptance and knowledge of the fact that the inauguration of radiotherapy as a new scientific speciality was performed by Leopold Freund 100 years ago. With a clear and logical rationale, Freund provided the first scientific proof of the biological effectiveness of X-rays on a 5-year-old patient and performed the world's first successful treatment with X-rays. Before Freund's historical experimental treatments, which started in Vienna on November 24th, 1896, there were several suggestions and attempts at the therapeutic use of X-rays, however none of these mostly one-of-a-kind attempts was successful, and there was no scientific proof of a therapeutic effectiveness of X-rays in these previous experiments.