Not to be confused with chemotherapy.
How it works
A high-powered beam of energy is shone on your body. This energy is not visible, and at the right size to damage DNA, a substance inside cells that they use to divide. This radiation damages DNA in both your healthy and cancerous cells; but since your cancerous cells divide much more often, and in a much less organized manner, cancer cells are more easily destroyed by radiation. The healthy cells of the body divide more slowly, and thus are able to repair the damage at a faster rate.
How it's administered
Radiation can be administered in two ways:
1. From the outside, through a machine called a linear accelerator.
2. From the inside, through pellets of material that give off radiation inside your body.
Treatment is usually given 5 days a week for up to 7 weeks. Sometimes radiation may be given twice a day for 1 week.
Since the daily appointments usually take about 30 minutes, you'll most likely be able to follow most of your normal routine during treatment.
Why it's important to have radiation done
Radiation is effective at not only treating the cancer, but also at making sure the cancer doesn't come back. Since individual cancer cells are so small that they can't be detected by any scans or tests, radiation therapy is useful even after the cancer is "gone" to try and catch any remaining cancer cells that are too small to be otherwise detected.
Women who do not undergo radiation therapy after surgical removal of cancer are 60% more likely to have the surgery come back, as compared to women who do have radiation.
Drawbacks of radiation therapy
Radiation is not an option for you if:
1. you have already had radiation to that area of the body
2. you have a connective tissue disease, such as scleroderma or vasculitis, which makes you extra-sensitive to the side effects of radiation
3. you are pregnant
4. you are not willing to commit to the daily schedule of radiation therapy, or distance makes it impossible
Radiation therapy may cause skin rashes and other uncomfortable skin irritation, but does not actually hurt during administration.
Radiation therapy also may cause hair loss on the area of the body being treated, such as the nipple or underarm. It will not cause hair loss on the head.
Radiation may cause fatigue, which can last up to months after treatment.
If done in more advanced stages of cancer, where radiation takes place on the stomach, brain, or digestive system, you will experience nausea and vomiting, but nausea does not usually occur for radiation on other body parts.