RADIOTHERAPY

Radiation therapy, also called radiotherapy, is a type of cancer treatment using beams of intense energy to kill cancer cells by destroying their genetic material. Genetic material controls how cells grow and divide. Modern methods of radiation are precise. They aim beams directly at cancer while protecting healthy tissues from high doses of radiation. And the rare healthy cells affected can also repair themselves more easily than cancer cells. Radiation therapy most often uses X-rays. But other types of radiation therapy exist, including proton radiation. Radiation therapy can also be given inside the body (brachytherapy). Side effects, if any, can be controlled during treatment, often outpatient treatment, and most side effects would go away after treatment. It is important to know that, sometimes, the cancer responds to treatment right away, but in most cases, it may take weeks or months to see the treatment working.

Source: https://www.mayoclinic.org/tests-procedures/radiation-therapy/about/pac-20385162