How does radiation therapy work?
Radiation therapy, or radiotherapy, is the use of various forms of radiation to safely and effectively treat cancer and other diseases. Radiation therapy works by damaging the genetic material within cancer cells and limiting their ability to successfully reproduce. When these damaged cancer cells die, the body naturally eliminates them. Normal cells are also affected by radiation, but they are able to repair themselves in a way that cancer cells cannot. In addition, your radiation oncologist will develop a plan to deliver the radiation to the tumor area, shielding as much surrounding normal tissue as possible.
Your radiation oncologist may recommend using radiation therapy in a number of different ways. Sometimes the goal is to cure the cancer. In this case, radiation therapy may be used to:
- Destroy tumors that have not spread to other parts of your body and cure you of disease.
- Reduce the risk that cancer will return after you undergo surgery or chemotherapy by killing small amounts of cancer that might remain.
- Shrink the cancer before surgery.
In other cases, the goal is to reduce the symptoms caused by growing tumors and to improve your quality of life. When radiation therapy is administered for this purpose, it is called palliative care or palliation. In this instance, radiation may be used to:
- Shrink tumors that are interfering with your quality of life, such as a lung tumor that is causing shortness of breath.
- Relieve pain by reducing the size of a tumor.
It is important for you to discuss the goal of your treatment with your radiation oncologist.
Some patients are concerned that radiation therapy will cause another cancer. In fact, the risk of developing a second tumor because of radiation therapy is very low. For many people, radiation therapy can cure the cancer. This benefit far outweighs any small risk that the treatment could cause a later cancer. However, you should discuss the risks and benefits of all of your treatments with your treatment team. If you smoke, the most important thing you can do to reduce your risk of a second cancer is to quit smoking.
Radiation therapy has been used safely and effectively to treat diseases for more than 100 years.
What are the different kinds of radiation?
The goal of radiation therapy is to get enough radiation into the body to kill the cancer cells while preventing damage to healthy tissue. There are several ways to do this. Depending on the location, size and type of cancer, you may receive one or a combination of techniques. Your treatment team will help you to decide which treatments are best for you.
Radiation therapy can be delivered in two ways, externally and internally. During external beam radiation therapy, the radiation oncology team uses a machine to direct high-energy X-rays at the cancer. Internal radiation therapy, called brachytherapy, involves placing radioactive sources (for example, radioactive seeds) inside your body.