Radiation therapy is a cancer treatment that uses high-energy X-rays. A machine directs the rays of energy to the area of cancer. Radiation therapy is also called radiotherapy. Its goal is to kill or shrink cancer cells.
Radiation therapy is not always part of the main treatment for people with ALL. But it may be used in certain situations. Your doctor may recommend radiation therapy for these reasons:
You’re having a stem cell transplant. You may get radiation to your whole body to help kill hiding leukemia cells. This is called total body irradiation (TBI) and may be given along with chemotherapy. This is rarely done for ALL, but may be used in certain cases. Radiation therapy kills not only leukemia cells, but also normal bone marrow cells. This helps prevent the rejection of stem cell transplants. If you need to have a transplant, you may have total body irradiation (TBI). This sends radiation in equal doses to all parts of your body.
You need radiation to help manage symptoms. For example, radiation can help with bone pain caused by the growth of leukemia cells in bone marrow. Killing the cancer cells can ease the pain they are causing.
ALL cells have spread to your brain, spine, or another organ. Radiation can give focused treatment on the leukemia cells in these parts of your body. In rare cases, a tumor may grow that causes problems with the function of an organ. Radiation can be used to shrink the tumor.
Radiation can sometimes be given as a preventive (prophylactic) treatment to the brain, or brain and spine to destroy any cells that may be hiding or not reached with chemotherapy.
You will receive radiation treatments either as an outpatient or as an inpatient. Outpatient means you go home the same day. Inpatient means you stay overnight in the hospital. For treatment directed at just a small part of your body, you can likely do this as an outpatient. If you’re getting ready for a stem cell transplant, you will have the treatments as an inpatient.
To prepare for your treatment, you will have a session called a simulation. During this session, your radiation therapist decides which position you’ll need to be in during treatments. The radiation needs to be pointed at the exact same spot on your body each time. This is called your treatment field or port. After you lie in a comfortable position, the therapist will see where the radiation needs to go. Then he or she marks your body with ink that won’t wash off easily in the shower. Lights from the machine will line up with these marks to be sure radiation is getting to the right part of your body.
The treatment is a lot like getting an X-ray. You stay in the radiation room for about an hour. The radiation will take about 15 minutes.
You’ll lie on a table while the machine is placed over you. It will not touch you. The radiation therapist will line up the machine exactly with your marked treatment fields. The radiation therapist will leave the room to run the machine, but can see and hear you the whole time. You will be able to talk to each other over an intercom. You may hear whirring or clicking noises. The procedure is painless. You will not be radioactive afterward.
If you’re having total body irradiation as part of a stem cell transplant, you will stand in a special machine or lie down on either your stomach or your back. Special shields will be used to protect certain organs from high-dose radiation. These include your lungs, heart, and kidneys.
Radiation affects normal cells as well as leukemia cells. Because of this, you may have side effects from this treatment. The severity of side effects depends on the dose, frequency, and location of the treatments. Some people have no side effects.
These may include:
Loss of appetite
Diarrhea, if your abdomen is treated
Sore mouth (mucositis), if the head and neck are treated
Low blood counts
These may not show up for several years after treatment is over. They may include:
Chronic skin problems, such as redness
Inflammation of the lungs (interstitial pneumonitis)
Decreased bone and soft tissue growth, which mostly affects the long bones in children
Slow intellectual development in children who get radiation to the brain as part of their treatment
Clouding of the lenses of the eye (cataracts)
Less able to have children (decrease or loss of fertility)
Growth of another kind of cancer
The immediate side effects of total body irradiation (TBI) can be more severe. They include an increased risk for infection because of a decrease in your white blood cells, and damage to skin and mucous membranes.
If you have side effects, your doctor may change the dose of your radiation or stop treatment until your side effects improve. Tell your doctor about any side effects you have. They will usually get better over time after your treatment ends.
Talk with your healthcare providers about what symptoms to watch for, and when to call them. Make sure you know what number to call with questions or problems, even on evenings and weekends.
It may be helpful to keep a diary of your side effects. Write down any changes you notice, how severe they are, and when they happen. A written list can make it easier for you to remember your questions when you go to your next appointment. It can also make it easier for you to work with your medical team to make a plan to manage your side effects.