n. The therapeutic use of ionizing radiation, almost exclusively used for the treatment of malignant disease.
the GNU version of the Collaborative International Dictionary of English
n. Treatment of disease by means of x-rays or radioactivity. Radiotherapy of cancer is based on the fact that cancer cells are more sensitive to radiation than most other cells in the body.
The Century Dictionary and Cyclopedia
n. Treatment of disease by any of the forms of radioactivity.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
n. (medicine) the treatment of disease (especially cancer) by exposure to a radioactive substance
Word Usage
"As part of a curative approach to mesothelioma radiotherapy is also commonly applied to the sites of chest drain insertion, in order to prevent growth of the tumor along the track in the chest wall."