Radiation therapy uses high-energy radiation from X-rays, protons, gamma rays and other energy sources to destroy cancer cells. Radiation can be External, coming from machines outside the body that deliver radiation beams into the body (external-beam radiation therapy) Internal, delivered by radioactive material that is placed in or near tumors in the body (internal radiation therapy or brachytherapy). Cancer cells grow and divide faster than normal cells. Radiation therapy works by damaging the DNA inside cells. This treatment prevents cancer cells from growing and dividing and causes them to die. Radiation also affects nearby healthy cells, but they can repair the damage.
Radiation therapy can treat almost any type of cancer. Whether you need radiation therapy — and the type of radiation you need — depends on your general health and the type of cancer.
Internal Radiation Therapy (Brachytherapy) involves placing a radiation source, such as capsules, ribbons or seeds, inside the body. The radiation source stays in or near a tumor for anywhere from a few minutes to years, depending on your individual needs.
Stereotactic radiosurgery (SRS) is a form of radiation therapy that delivers highly precise doses of radiation from outside the body to targeted areas inside the body. Despite the word surgery in the name, SRS involves no incisions.
