Find out about COVID-19, COVID-19 vaccines, and Mayo Clinic patient and visitor updates.
Featured conditions Brain tumor, breast cancer, colon cancer, congenital heart disease, heart arrhythmia. See more conditions.
Featured conditions
External beam radiation uses high-powered beams of energy to kill cancer cells. Beams of radiation are precisely aimed at the cancer using a machine that moves around your body.
Mayo Clinic does not endorse companies or products. Advertising revenue supports our not-for-profit mission.
Check out these best-sellers and special offers on books and newsletters from Mayo Clinic Press.