Abstract
From the discovery of x-rays in November 1895 and the first publication in December 1895 it did not take long for the first x-ray therapy of cancer in January 1896. The first 25 years in the history of radiotherapy was not a very flattering period for the discipline. During the following 25 years, however, important developments in clinical radiotherapy occurred and in some countries the specialty of radiotherapy was established in the 1930s. In the last 50 years gradual changes have taken place and now modern radiotherapy is an established curative method in the treatment of cancer. The scientific background of radiotherapy is solid, and the understanding of cancer biology and radiobiology has improved drastically. The radiotherapists of today are cancer specialists, oncologists. The technical development has been enormous. The future of radiation oncology looks very promising, with local cancer treatment being shown to be most effective.