Radiation therapy (also called radiotherapy) is a cancer treatment that uses high doses of radiation to kill cancer cells and stop them from spreading. At low doses, radiation is used as an x-ray to see inside your body and take pictures, such as x-rays of your teeth or broken bones. Radiation used in cancer treatment works in much the same way, except that it is given at higher doses.
Radiation therapy can be external beam (when a machine outside your body aims radiation at cancer cells) or internal (when radiation is put inside your body, in or near the cancer cells). Sometimes people get both forms of radiation therapy.
Many people with cancer need radiation therapy. In fact, about 60 percent of people with cancer get radiation therapy. Sometimes, radiation therapy is the only kind of cancer treatment people need.
Given in high doses, radiation kills or slows the growth of cancer cells. It is used to:
Treat cancer: Radiation can be used to cure, stop, or slow the growth of cancer.
Reduce symptoms: When a cure is not possible, radiation may be used to shrink cancer tumors in order to reduce pressure. Radiation therapy used in this way can treat problems such as pain, or it can prevent problems such as blindness or loss of bowel and bladder control.
Radiation therapy does not kill cancer cells right away. It takes days or weeks of treatment before cancer cells start to die. Cancer cells keep dying for weeks or months after radiation therapy ends.
Radiation not only kills or slows the growth of cancer cells, it can also affect nearby healthy cells. The healthy cells almost always recover after treatment is over. But sometimes people may have side effects that do not get better or are severe. Doctors try to protect healthy cells during treatment by:
▪ Using as low a dose of radiation as possible. The radiation dose is balanced between being high enough to kill cancer cells yet low enough to limit damage to healthy cells.
▪ Spreading out treatment over time. You may get radiation therapy once a day for several weeks or in smaller doses twice a day. Spreading out the radiation dose allows normal cells to recover while cancer cells die.
▪ Aiming radiation at a precise part of your body. New techniques, such as IMRT and 3-D conformal radiation therapy, allow your doctor to aim higher doses of radiation at your cancer while reducing the radiation to nearby healthy tissue.
▪ Using medicines. Some drugs can help protect certain parts of your body, such as the salivary glands that make saliva.
Yes, radiation therapy is often used with other cancer treatments. Here are some examples:
▪ Radiation therapy and surgery. Radiation may be given before, during, or after surgery. Doctors may use radiation to shrink the size of the cancer before surgery, or they may use radiation after surgery to kill any cancer cells that remain. Sometimes, radiation therapy is given during surgery so that it goes straight to the cancer without passing through the skin. This is called intra-operative radiation.
▪ Radiation therapy and chemotherapy. Radiation may be given before, during, or after chemotherapy. Before or during chemotherapy, radiation therapy can shrink the cancer so that chemotherapy works better. Sometimes, chemotherapy is given to help radiation therapy work better. After chemotherapy, radiation therapy can be used to kill any cancer cells that remain.
No, radiation therapy does not hurt while it is being given. But the side effects that people may get from radiation therapy can cause pain or discomfort.
Your body uses a lot of energy to heal during radiation therapy. It is important that you eat enough calories and protein to keep your weight the same during this time. Ask your doctor or nurse if you need a special diet while you are getting radiation therapy. You might also ﬁnd it helpful to speak with a dietitian.
Some people are able to work full-time during radiation therapy. Others can only work part-time or not at all. How much you are able to work depends on how you feel. Ask your doctor or nurse what you may expect based on the treatment you are getting. You are likely to feel well enough to work when you start radiation therapy. As time goes on, do not be surprised if you are more tired, have less energy, or feel weak. Once you have ﬁnished your treatment, it may take a few weeks or many months for you to feel better. You may get to a point during your radiation therapy when you feel too sick to work.
Once you have ﬁnished radiation therapy, you will need follow-up care for the rest of your life. Follow-up care refers to checkups with your radiation oncologist after your course of radiation therapy is over. During these checkups, your doctor or nurse will see how well the radiation therapy worked, check for other signs of cancer, look for late side effects, and talk with you about your treatment and care.
You have gone through a lot with cancer and radiation therapy. Now you may be even more aware of your body and how you feel each day. Pay attention to changes in your body and let your doctor know if you have:
• A pain that does not go away
• New lumps, swellings, rashes, bruises, or bleeding
• Appetite changes, nausea, vomiting, diarrhea, or constipation
• Weight loss that you cannot explain
• A fever, cough, or hoarseness that does not go away
• Any other symptoms that worry you
▪ You may be asked to change into a hospital gown or robe.
▪ You will go to a treatment room where you will receive radiation.
▪ Depending on where your cancer is, you will either sit in a chair or lie down on a treatment table. The radiation therapist will use your body mold and skin marks to help you get into position.
▪ You may see colored lights pointed at your skin marks. These lights are harmless and help the therapist position you for treatment each day.
▪ You will need to stay very still so the radiation goes to the exact same place each time. You can breathe as you always do and do not have to hold your breath. The radiation therapist will leave the room just before your treatment begins. He or she will go to a nearby room to control the radiation machine and watch you on a TV screen or through a window. You are not alone, even though it may feel that way. He or she can hear and talk with you through a speaker in your treatment room. Make sure to tell the therapist if you feel sick or are uncomfortable. He or she can stop the radiation machine at any time. You cannot feel, hear, see, or smell radiation. Your entire visit may last from 30 minutes to 1 hour. Most of that time is spent setting you in the correct position. You will get radiation for only 1 to 5 minutes. If you are getting IMRT, your treatment may last longer. Your visit may also take longer if your treatment team needs to take and review x-rays.
No, external beam radiation therapy does not make people radioactive. You may safely be around other people, even babies and young children.
Many people who get radiation therapy have skin changes and some fatigue. Other side effects depend on the part of your body being treated.
Skin changes may include dryness, itching, peeling, or blistering. These changes occur because radiation therapy damages healthy skin cells in the treatment area. You will need to take special care of your skin during radiation therapy. Fatigue is often described as feeling worn out or exhausted. There are many ways to manage fatigue. Depending on the part of your body being treated, you may also have:
• Hair loss in treatment area
• Mouth problems
• Nausea and vomiting
• Sexual changes
• Trouble swallowing
• Urinary and bladder changes
Most of these side effects go away within 2 months after radiation therapy is ﬁnished.