Radiation therapy is the use of radiation to treat cancer. This treatment is used to: 

• Cure cancer by destroying cancer cells 
• Control cancer by keeping cancer cells from growing and spreading 
• Reduce cancer symptoms such as pain

There are two types of radiation therapy: 

With external radiation therapy, a machine directs high-energy rays at the cancer. This is the most common type used. The skin is marked with ink so that the treatment is done at the same spot each time. The treatment is often done 5 days a week for 2 to 7 weeks. The first appointment may take a few hours but after that, treatments only take a few minutes. 

With internal radiation therapy, also called brachytherapy or implant therapy, the radiation source is put in the body in or near the cancer. It is sealed in a small holder called an implant. The implant may be thin wires, plastic tubes, capsules or seeds. The implant is placed for a few hours, a few days, or it may be left in place. Your doctor will decide the amount of time that the implant will be in place. If it is to be left in your body, the implant will lose its radioactivity in a short time. 

Internal radiation allows the doctor to give a higher total dose of radiation in a shorter time than can be done with external treatment. Internal radiation therapy may also be done using radioactive liquid that is taken by mouth or put into the body. 

Your doctor will talk about safety measures to take at home and around other people. These measures will be for a limited time. Your doctor may order both types of radiation therapy. Radiation may be used alone or with other cancer treatments such as surgery or chemotherapy. Radiation therapy affects both cancer cells and normal cells that are in the treatment site. The effects on normal cells are called treatment side effects. The most common side effects are feeling tired and skin problems. Other side effects may occur depending on the treatment site. The side effects often go away after treatment. Talk to your doctor or nurse if you have any side effects.

Talk to the doctor if you have any questions or concerns.