[ rey-dee-oh-ther-uh-pee ]
/ ˌreɪ di oʊˈθɛr ə pi /

noun Medicine/Medical.

treatment of disease by means of x-rays or of radioactive substances.

Origin of radiotherapy

First recorded in 1900–05; radio- + therapy
Also called radiation therapy.

Related forms

ra·di·o·ther·a·pist, noun Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for radiotherapy

British Dictionary definitions for radiotherapy


/ (ˌreɪdɪəʊˈθɛrəpɪ) /


the treatment of disease, esp cancer, by means of alpha or beta particles emitted from an implanted or ingested radioisotope, or by means of a beam of high-energy radiationCompare chemotherapy

Derived Forms

radiotherapeutic (ˌreɪdɪəʊˌθɛrəˈpjuːtɪk), adjectiveradiotherapeutically, adverbradiotherapist, noun
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Medicine definitions for radiotherapy


[ rā′dē-ō-thĕrə-pē ]


Treatment of disease with radiation, especially by selective irradiation with x-rays or other ionizing radiation and by ingestion of radioisotopes.

Related forms

ra′di•o•thera•pist n.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.