Question: How is gamma radiation used in medicine?

Iain Bethune answered on 17 Jun 2015:

Gamma radiation (high energy electromagnetic radiation) is used to treat cancers. It’s called radiotherapy. It works by focusing a beam of gamma rays in the area with the cancer. Usually the beam is rotated around you, always passing through the cancer site, so that the cancer absorbs the most radiation, and the surrounding healthy tissue absorbs less because the beam only passes through it twice per rotation, rather than all the time. Your cells absorb the gamma rays, which can mutate or kill them, thus destroying the cancer.