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

• radiotherapist
  noun
• radiotherapeutic
  adjective
• radiotherapeutically
  adverb

Etymology

Origin of radiotherapy

First recorded in 1900–05; radio- + therapy

Example Sentences

The clinical trial was designed to identify the highest safe dose and evaluate the potential benefits of controlled-release niacin when combined with standard chemotherapy and radiotherapy.

From Science Daily • Jun. 22, 2026

"This technology lets us focus a powerful and precise beam of radiotherapy directly on to the cancer, limiting the damage to healthy cells," he said.

From BBC • Jun. 9, 2026

Trials are already under way to see if the precision radiotherapy can be used on high-risk prostate cancer patients.

From BBC • Jun. 9, 2026

Since having surgery to remove as much of the tumour as possible, he has undergone chemotherapy and radiotherapy.

From BBC • Jun. 2, 2026

The 64-year-old avoided chemotherapy thanks to the Prosigna test and has instead received eight years of radiotherapy and hormone therapy.

From BBC • May 30, 2026