radiotherapy

American  

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

noun

Medicine/Medical.

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

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radiotherapy British  

/ ˌreɪdɪəʊˈθɛrəpɪ, ˌreɪdɪəʊˌθɛrəˈpjuːtɪk /

noun

1. 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 radiation Compare chemotherapy

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Other Word Forms

• radiotherapeutic
  adjective
• radiotherapeutically
  adverb
• radiotherapist
  noun

Etymology

Origin of radiotherapy

First recorded in 1900–05; radio- + therapy

Example Sentences

These patients often undergo radiotherapy near the mouth, which can damage salivary glands and reduce saliva production.

From Science Daily • Apr. 5, 2026

Julia Endacott works as a women's health physiotherapist and finished radiotherapy for breast cancer two weeks ago.

From BBC • Mar. 23, 2026

"There are the physical scars which for those who have pelvic radiotherapy can mean dealing with bowel, vulva, cervical and vaginal scarring which is horrendously painful," she said.

From BBC • Mar. 18, 2026

Trish is, similarly, calling for a clinic to deal with the after-effects of pelvic radiotherapy.

From BBC • Mar. 18, 2026

As part of her treatment, she needed radiotherapy followed by an operation to remove two muscles from her right thigh, which left her with minimal movement.

From BBC • Mar. 16, 2026