ra·​dio·​ther·​a·​py ˌrā-dē-ō-ˈther-ə-pē How to pronounce radiotherapy (audio)
: the treatment of disease with radiation (such as X-rays)
radiotherapist noun

Examples of radiotherapy in a Sentence

Recent Examples on the Web Whole-brain radiotherapy: With this method, the entire brain is treated with radiation. Benjamin Leach, Verywell Health, 23 Aug. 2023 For instance, Silent Stories, in which artist Katharine Dowson casted the radiotherapy masks used by patients, is accompanied by a soundscape of patients reflecting on the impacts of cancer treatment and radiotherapy. Antonia Mufarech, Smithsonian Magazine, 26 May 2022 They are used in CT scanners, for x-rays of bones and for radiotherapy of malignant tumors. Chandrashekhar Joshi, Scientific American, 1 July 2021 Individuals diagnosed with muscle-invasive bladder cancer face a difficult treatment decision - intensive radiotherapy or complete surgical removal of their bladder. Carolyn Graybeal, Discover Magazine, 11 Feb. 2016 Will eyebrows fall out with radiotherapy? Amanda Mitchell, Allure, 14 Oct. 2020 Russia also imports a large share of its medical equipment, such as pacemakers and radiotherapy devices, from the European Union and the United States, and its reliance is particularly acute for the most complex and critical machines. Fox News, 24 Jan. 2023 Although usually associated with radiotherapy, it has also been observed after other local cancer treatments, such as cryotherapy and hyperthermia. James Welsh, Discover Magazine, 7 Apr. 2014 The compounds also enhance the action of radiotherapy. Katharine Quarmby, Discover Magazine, 18 Aug. 2015 See More

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'radiotherapy.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History


International Scientific Vocabulary

First Known Use

1902, in the meaning defined above

Time Traveler
The first known use of radiotherapy was in 1902

Dictionary Entries Near radiotherapy

Cite this Entry

“Radiotherapy.” Dictionary, Merriam-Webster, Accessed 29 Nov. 2023.

Medical Definition


ra·​dio·​ther·​a·​py ˌrād-ē-ō-ˈther-ə-pē How to pronounce radiotherapy (audio)
plural radiotherapies
: the treatment of disease by means of radiation (as X-rays)

called also radiation therapy, radium therapy

compare radiodiagnosis

More from Merriam-Webster on radiotherapy

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