Radiation therapy for advanced cancer

Radiation therapy uses high-energy x-rays to kill cancer cells or shrink tumors. For cancer that has not spread too far, radiation therapy can sometimes cure the cancer, either by itself or along with other treatments.

In advanced cancer, radiation therapy is often used to shrink tumors to reduce pain or other symptoms. This is called palliative radiation.

There are different types of radiation therapy.

External beam radiation therapy: This is like having a regular x-ray except it lasts a little longer. A machine creates strong radiation beams that are directed at the tumor or tumors. Patients usually have treatments 5 days a week for several weeks. Sometimes, this can be shortened to just 1 or 2 days by giving more radiation during each session.

The main side effects are tiredness (fatigue) and skin that may look and feel sunburned in the areas the radiation beams passed through. Radiation to the head and neck area can damage the glands that make saliva and cause a sore throat or mouth sores. Some people have trouble swallowing or lose their ability to taste food. Radiation to the stomach area can cause nausea, vomiting, diarrhea, and possible damage to the intestines. Radiation to the chest area can cause scars in the lungs that may make some people short of breath. Brain radiation can sometimes cause problems with thinking or memory that start many months to years after treatment.

Internal radiation therapy (brachytherapy): This type of treatment uses small “seeds” of radioactive material (about the size of a grain of rice) that are put right into the cancer. The radiation from the seeds travels only a short distance, so the normal tissue around the tumor is less damaged.

Radiopharmaceuticals: Some radioactive materials (such as strontium-89 or samarium-153) are dissolved into liquids that can be given into a vein. They travel through the blood and are drawn to areas of bone that contain cancer. The radiation given off by the drug kills cancer cells and relieves bone pain, but it does not cure the cancer. If the cancer has spread to many bones, this may work better than using external beam radiation, which only treats a small area.

Sometimes different types of radiation are used together. To learn more about radiation, please see Understanding Radiation Therapy: A Guide for Patients and Families.