There are several forms of radiation therapy that can be used to treat cancer. These include:
External Beam Radiation Therapy
In external beam radiation therapy, radiation is produced by a machine called a linear accelerator. Short bursts of x-rays are fired from the machine at your cancer. The x-rays come out in a square-shaped manner, and the radiation oncologist designs special blocks to shape the radiation beam so that it treats the cancer and as little normal tissue as possible.
Like chemotherapy, the side effects from radiation result from injury to the normal tissues. There are many new ways that the radiation oncologist can customize your treatment to try and kill as much cancer while sparing as much normal tissue as possible. The radiation oncologist will determine how many treatments you will receive. Each treatment generally only takes a few minutes, and the total treatment time can range from 5-8 weeks depending on the total dose required.
Radiation therapy can be given to treat cancer at its initial site or once it has spread. In some cases, once cancer has spread, radiation is no longer curative. However, the treatments can help resolve problems that the cancer may be causing, including pain and weakness.
Many people believe that once you have received a certain dose of radiation you can no longer get any more treatment. It is true that each tissue in the body can only safely tolerate a certain dose of radiation. However, the therapy is very focused and it is possible that you can get additional treatments to an already treated area, or certainly to an area not yet treated. Ask your radiation oncologist about what dose you can safely receive.
Radiation therapy is used in most cases of breast cancer, either after a lumpectomy or a mastectomy. The standard treatment is after lumpectomy, when the remainder of the breast is still at risk for disease. But, if the tumor is large or any of the lymph nodes have cancer in them, your radiation oncologist will probably recommend you receive radiation therapy as well. In the Canada, if you need chemotherapy and radiation therapy, chemotherapy usually comes first. Unlike other cancers where both therapies are used, in breast cancer they are not offered at the same time because of an increased risk of side effects.
“Brachy” means “short,” and this form of treatment uses radiation therapy at very short distances. When you receive external beam radiotherapy, the radiation comes out of a machine located about 40 inches above you. Brachytherapy, however, delivers radiation directly to the cancer via a radioactive implant inside the body. This special type of treatment is used at many centers in the United States. Ask your radiation oncologist if it is appropriate for you.
When to Contact Your Health Care Provider
Call your health care provider if you:
- Develop side effects from the treatment
- Develop new or unusual symptoms
- Your skin is red, blistered, or swollen