What is radiation therapy?
Radiation therapy is a cancer treatment that uses beams of radiation to destroy cancer cells and shrink cancer tumors.
Doctors use radiation to treat many types of cancer, including head, neck, brain, and breast cancer
Radiation may not destroy all the cancer cells and may destroy some normal cells, which can cause some side effects
Doctors may treat your cancer with radiation and another type of cancer treatment, such as chemotherapy Chemotherapy Chemotherapy is a drug that destroys cancer cells. Chemotherapy works by shutting down cell growth. But since all cells in the body grow, chemotherapy drugs also destroy some normal cells and... read more
Radiation therapy may raise your chances of getting other cancers in the future
Radiation therapy kills all kinds of cells in your body, not just cancer cells. The radiation has to be aimed very carefully so that it hits mainly the cancer and not healthy tissue.
Types of radiation therapy
Most radiation therapy uses a machine that sends a beam of radiation to the part of your body that has cancer. There are two kinds of radiation beams:
Gamma rays
Proton beams
Proton beams can be aimed more precisely than gamma rays. Whatever kind of beam is used, most people get radiation therapy every day for 6 to 8 weeks.
Doctors often use MRI Magnetic Resonance Imaging (MRI) MRI is a test that uses a machine with a powerful magnet to make pictures of the inside of your body. A computer records changes in the magnetic field around your body. The computer then uses... read more
(magnetic resonance imaging), CT (computed tomography) scan Computed Tomography A CT scan uses a large machine shaped like a large donut to take x-rays from many angles. A computer then takes the x-rays and creates many detailed pictures of the inside of your body. Each... read more 
, and ultrasound Ultrasonography Ultrasonography is a safe imaging test that uses sound waves to create a moving picture of the insides of your body. Ultrasonography doesn't use radiation (x-rays). Ultrasonography is also called... read more 
during radiation therapy to be able to aim the radiation beam more precisely onto the tumor
Another way doctors avoid harming healthy tissue is to shoot the radiation beam at your cancer from different sides of your body and at different angles. That way, the beam always hits the cancer, but the same healthy tissue doesn't get hit each time.
Other types of radiation therapy include:
A radioactive substance that doctors inject into your vein that travels through your blood to the cancer cells
Small radioactive pellets (seeds) that doctors place into the cancer tumor
What are the side effects of radiation therapy?
Feeling weak and tired
Mouth sores
Skin problems, such as redness, itching, and peeling
Pain when you swallow
Swelling in your lungs
Feeling sick to your stomach or throwing up
Feeling like you need to urinate (pee) more than usual or having pain when urinating
Bruising easily
Radiation therapy can damage normal tissue and gives you a higher chance of developing other cancers in the future. The risk depends on your age and where in your body you get radiation therapy.
