For some people, radiation may be the only treatment you need. But, most often, you will have radiation therapy with other cancer treatments, such as surgery, chemotherapy, and immunotherapy. Radiation therapy may be given before, during, or after these other treatments to improve the chances that treatment will work. The timing of when radiation therapy is given depends on the type of cancer being treated and whether the goal of radiation therapy is to treat the cancer or ease symptoms.
When radiation is combined with surgery, it can be given:
- Before surgery, to shrink the size of the cancer so it can be removed by surgery and be less likely to return.
- During surgery, so that it goes straight to the cancer without passing through the skin. Radiation therapy used this way is called intraoperative radiation. With this technique, doctors can more easily protect nearby normal tissues from radiation.
- After surgery to kill any cancer cells that remain.
There are two main types of radiation therapy, external beam and internal.
The type of radiation therapy that you may have depends on many factors, including:
- The type of cancer
- The size of the tumor
- The tumor’s location in the body
- How close the tumor is to normal tissues that are sensitive to radiation
- Your general health and medical history
- Whether you will have other types of cancer treatment
- Other factors, such as your age and other medical conditions
Brachytherapy is one type of radiation therapy that's used to treat cancers of the head and neck, breast, cervix, prostate, and eye and is sometimes called internal radiation. Brachytherapy is a procedure that involves placing high-powered radiation inside your body.
Brachytherapy allows doctors to deliver higher doses of radiation to more-specific areas of the body, compared with the conventional form of radiation therapy (external beam radiation) that projects radiation from a machine outside of your body. Brachytherapy may cause fewer side effects than does external beam radiation, and the treatment time is usually shorter with brachytherapy.