Kaohsiung Armed Forces General Hospital

Patient information: Radiation therapy (The Basics)
Written by the doctors and editors at UpToDate
What is radiation therapy? — Radiation therapy is a type of cancer treatment. It uses high doses of X-rays, called radiation, to kill cancer cells. There are 2 types of radiation therapy, depending on where the source of the radiation is.
■ In “external-beam radiation therapy,” the radiation comes from a machine that is outside the body. This article discusses external-beam radiation therapy.
■ In “internal radiation therapy,” the radiation comes from a source that is put inside the body.
Doctors can use radiation to treat many different types of cancers. Some people are treated only with radiation therapy. Other people have radiation therapy along with other cancer treatments.
What happens before I start radiation therapy? — Before you start treatment, you will meet with a team of doctors and nurses to plan your radiation therapy. They will probably do an exam and tests. They will put a small dot of ink on your body to mark the area that will be treated. They might also make a mold or mask of a part of your body for you to wear during treatment.
What happens during radiation therapy? — People get radiation therapy in the hospital, but they can go home after each treatment. They do not usually need to stay in the hospital. The number of treatments a person needs depends on the type of cancer. Some people get radiation only 1 time. Other people get radiation 1 time a day, 5 days a week, for up to 7 weeks.
For each treatment, you will wear your mold or mask (if you have one) and sit or lie down in front of the machine. You will need to stay still. Your doctor will line up the machine with your dot of ink. That way, the X-rays will travel only through the part of your body with the cancer. The X-rays will not travel through other parts of your body.
It doesn’t hurt to get radiation. The machine sends radiation through the cancer and the area right around it for about 1 to 5 minutes.
Your doctor or nurse will give you instructions about what to wear and what you can or can’t have on your body. For example, most people should not have bandages, jewelry, or other items on the skin in the area being treated.
What are the side effects of radiation? — People can have different side effects from radiation. The side effects will depend on:
■ The part of the body being treated — As the X-rays travel through the body, they can damage the skin and the organs or tissues next to the cancer.
■ The dose of radiation
■ The number of treatments and the treatment schedule
People can have side effects hours or days after treatment. Common ones include:
■ Feeling tired, weak, or having no energy — These symptoms can get worse over the course of treatment.
■ Skin changes — The skin in the area being treated can peel, blister, itch or turn red.
Other side effects can happen hours or days after treatment. Depending on your treatment, your doctor will tell you the ones that you are likely to get.
People can also have side effects from radiation months or years after their treatment. These can include:
■ Trouble getting pregnant
■ Other types of cancers, although these are rare