ra·​dio·​ther·​a·​py | \ ˌrā-dē-ō-ˈther-ə-pē How to pronounce radiotherapy (audio) \

Definition of radiotherapy

: the treatment of disease with radiation (such as X-rays)

Keep scrolling for more

Other Words from radiotherapy

radiotherapist \ ˌrā-​dē-​ō-​ˈther-​ə-​pist How to pronounce radiotherapy (audio) \ noun

Examples of radiotherapy in a Sentence

Recent Examples on the Web After a hard and courageous battle through chemotherapy and radiotherapy, Sean received the all-clear the following July 2019 and is still officially in remission. Tommy Williams, Forbes, "Meet Super U: Startup Creating Premium Superfood Blends To The Improve Your Health," 9 Apr. 2021 Treating cancer more effectively Linear electron acceleration has long been used in radiotherapy to create X-rays for treating cancer. Andrea Willige, Forbes, "Particle Accelerators That Clean Power Plants – And A Lot More," 18 Mar. 2021 Combining radiotherapy with immunotherapy in novel ways can enhance results, by improving the immune system’s cancer recognition and rendering tumors less immunosuppressive. David L. Coddon, San Diego Union-Tribune, "Arts & Culture Newsletter: With her new album ‘Rare Bird,’ Sara Petite tries to find the silver linings," 25 Feb. 2021 Chemotherapy and radiotherapy notoriously cause a whole host of debilitating side effects, such as exhaustion, nausea and vomiting, and mood changes. Genevieve Richardson, SELF, "Why I Refuse to Use Cancer Metaphors About a ‘War,’ ‘Fight,’ or ‘Battle’," 7 Dec. 2020 The Wanted, is currently undergoing radiotherapy and chemotherapy treatment for an inoperable brain tumor. Rosy Cordero,, "The Wanted singer Tom Parker reveals inoperable brain tumor, promises to 'fight this all the way'," 12 Oct. 2020 Unlike Brown, Castillejo underwent only one stem-cell transplantation instead of two and did not have radiotherapy to his entire body as part of his treatment. Alisha Ebrahimji And Jacqueline Howard, CNN, "The first known person to be cured of HIV has died of cancer," 30 Sep. 2020 It has been used for decades to treat patients undergoing chemotherapy and radiotherapy for cancer. Scientific American, "The Potential Hazards Of Personalized Medicines," 10 Dec. 2019 The 53-year-old turned at first to radiotherapy, the hospital said. Author: Hannah Knowles, Anchorage Daily News, "Watch this woman play her violin in the middle of brain surgery," 20 Feb. 2020

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'radiotherapy.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

See More

First Known Use of radiotherapy

1902, in the meaning defined above

History and Etymology for radiotherapy

International Scientific Vocabulary

Keep scrolling for more

Learn More about radiotherapy

Time Traveler for radiotherapy

Time Traveler

The first known use of radiotherapy was in 1902

See more words from the same year

Statistics for radiotherapy

Last Updated

21 Apr 2021

Cite this Entry

“Radiotherapy.” Dictionary, Merriam-Webster, Accessed 18 May. 2021.

Style: MLA
MLACheck Mark Icon ChicagoCheck Mark Icon APACheck Mark Icon Merriam-WebsterCheck Mark Icon

Keep scrolling for more

More Definitions for radiotherapy


ra·​dio·​ther·​a·​py | \ ˌrād-ē-ō-ˈther-ə-pē How to pronounce radiotherapy (audio) \
plural radiotherapies

Medical Definition of radiotherapy

: 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 Encyclopedia article about radiotherapy

Comments on radiotherapy

What made you want to look up radiotherapy? Please tell us where you read or heard it (including the quote, if possible).


Test Your Vocabulary

Words Used by Nabokov Quiz

  • image1676440788
  • Choose the best definition or synonym for the word in bold: "There are some eructations that sound like cheers—at least, mine did." Lolita
Name That Thing

Test your visual vocabulary with our 10-question challenge!


Anagram puzzles meet word search.

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!