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.

---

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

---

Other Word Forms

• radiotherapist
  noun
• radiotherapeutic
  adjective
• radiotherapeutically
  adverb

Etymology

Origin of radiotherapy

First recorded in 1900–05; radio- + therapy

Example Sentences

See Examples For:

radiotherapy

She subsequently underwent brain surgery, radiotherapy and chemotherapy in an effort to keep the cancer at bay.

From Los Angeles Times ● Jul. 14, 2026

This is despite Healthineers’ growth prospects and leading position and margins in imaging and radiotherapy, the analysts write.

From The Wall Street Journal ● Jul. 9, 2026

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

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

He then had the new type of radiotherapy, targeting his prostate and surrounding lymph nodes, which he said was "easier to deal with".

From BBC ● Jun. 9, 2026