Radiation therapy is a treatment for cancer. It works by preventing cancer cells from growing and by destroying them.
The high-energy radiation used comes from:
Radiation therapy is also called radiotherapy, irradiation, or X-ray therapy.
Radiation therapy can be either:
External radiation therapy uses a large machine and special equipment to carefully aim the right amount of radiation at cancerous tumors.
With internal radiation therapy, doctors inject or implant a radioactive substance into the area with the tumor or cancer cells. In some cases, the patient swallows the material.
Some people may need both external radiation and internal radiation.
Besides killing cancer cells and shrinking tumors, radiation therapy also can harm normal cells. Normal cells are more likely to recover from its effects. The health care team will carefully check a teen's radiation doses to protect healthy tissue.
For external radiation therapy, teens usually go to the hospital or treatment center 4 to 5 days a week for several weeks. They'll get small daily doses of radiation, which helps protect the normal cells from damage. The weekend breaks help the cells recover from the radiation.
If you get radiation therapy, the radiation therapist will mark an area on your skin with ink. This "tattoo" helps show the treatment area.
Most of the time that you'll spend on the radiation treatment table involves positioning. The treatment itself takes only minutes. When you're in the right position:
Parents aren't allowed in the treatment room, but can wait nearby for you during therapy.
Most teens who get internal radiation treatment stay in the hospital for several days. The radioactive material is:
Doctors might do a minor surgery using anesthesia to place the material (for example, when treatment is in the uterus, esophagus, or airway).
Internal radiation therapy is also called brachytherapy, interstitial therapy, or implant therapy.
Teens may wonder whether they can touch or hug others during and after therapy.
Radiation can damage healthy cells. This damage can cause side effects such as skin problems, tiredness, and anemia. The type of side effects someone might get depends on the dose of radiation, whether it was internal or external, and the area treated.
Many patients have no side effects. When problems do happen:
Radiation therapy can also cause long-term side effects if it affects the normal cells surrounding the tumor. They can include learning issues, vision problems, hearing loss, and other problems.
Before your treatment, it may help to take a tour of the radiation department to see the radiation technologists and equipment so you can get familiar with them.
And you don't have to go it alone. The doctors, nurses, social workers, and other members of the cancer treatment team are there to help you before, during, and after cancer treatment.
You also can find information and support online at:
Reviewed by: Eric S. Sandler, MD
Date Reviewed: Aug 1, 2022