Radiation Therapy, Explained in Just 2 Minutes

In this video, learn how radiation therapy helps treat certain types of cancers.

Written by Lauren Smith, MA | Reviewed by Alexandra Schwarz, MD

Updated on November 30, 2023

---

Using X-rays to shrink cancer tumors may sound like something from a sci-fi movie, but it’s exactly how radiation therapy works. Radiation is a classic type of cancer treatment, dating back even earlier than chemotherapy.

Radiation therapy, sometimes called radiotherapy, uses high doses of radiation — much higher than what’s used to X-ray your bones. At these doses, the radiation mangles the DNA of the cancer cell, causing it to become damaged and die off. As these cancer cells are killed, the body can break them down further and eliminate them from the body. This process slows the growth of cancer cells and can shrink and potentially eliminate tumors.