radiation therapy: Quick Facts

Written and fact-checked by

The Information Architects of Encyclopaedia Britannica

Last updated

Nov. 3, 2026

News •

New pediatric consensus standardizes surgical management of Wilms tumor • Nov. 2, 2026, 2:43 PM ET (News-Medical)

Facts

Also Known As	radiotherapy • therapeutic radiology • radiation oncology • irradiation

Photos and Videos

linear accelerator; external beam radiation therapy

A radiation technologist operates a large linear accelerator machine, with red guide lasers visible and a computer monitor displaying data in the background.

Graph comparing how X-rays, gamma rays, and proton beams penetrate the body, showing absorbed radiation dose versus depth. X-ray and gamma ray curves decrease steadily, while the proton beam curve rises sharply to a Bragg peak at tumor depth, then drops off.

Types of radiation therapy explained

See All Videos and Images →

Topics

phototherapy PUVA therapy brachytherapy What Is Astatine Used For?How Radioactive Isotopes are Used in Medicine photodynamic therapy radioactive implant cancer nonsurgical therapy radiology targeted therapy anticancer drug chemotherapy History of Cancer: A Timeline

Dig Deeper: More Articles That Discuss This Topic

Key People

default image

John Joly

Irish geologist