How are gamma rays used in the medical field?

Gamma-rays can kill living cells, a fact which medicine uses to its advantage, using gamma-rays to kill cancerous cells.

Gamma rays and beta particles are all used to treat internal organs. X - rays are produced by firing electrons at a metal target and gamma rays are emitted by the nucleus of radioactive atoms. Gamma rays are used to kill cancer cells, and to medical equipment and in radioactive tracers.