Childhood Hodgkin lymphoma

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Side effects of radiation therapy for childhood HL

Side effects can happen with any type of treatment for childhood Hodgkin lymphoma (HL), but every child’s experience is different. Some children have many side effects. Others have few or none at all.

During radiation therapy, the healthcare team protects healthy cells in the treatment area as much as possible. But damage to these healthy cells may occur and cause side effects. Side effects can happen any time during, immediately after or a few days or weeks after radiation therapy. Sometimes late side effects develop months or years after radiation therapy. Most side effects go away on their own or can be treated, but some side effects may last a long time or become permanent.

Side effects of radiation therapy will depend mainly on the:

  • size of the area being treated
  • specific area or organs being treated
  • dose of radiation given at one time, which is called the dose per fraction
  • total dose of radiation given
  • treatment schedule
  • child’s age

Tell the healthcare team if your child has these side effects or others you think might be from radiation therapy. The sooner you tell them about any problems, the sooner they can suggest ways to help your child deal with them.

Skin reactions

Skin reactions occur because external beam radiation travels through the skin to reach the area being targeted for treatment. The skin in the treatment area may be red, itchy, dry and flaky. It may also peel and be tender or sore.

Most skin reactions occur within the first 2 weeks of radiation therapy. They usually go away a few weeks after treatment, but sometimes they can become long-term problems. The skin in the treatment area can become thinner. It may be smooth, tight and shiny as scar tissue forms. Skin can also be red or flushed when small blood vessels are widened from radiation. It can also become lighter or darker because the cells that produce the skin pigment are affected. Changes to the skin colour can be permanent.

Find out more about skin problems.

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Fatigue is one of the most common general side effects of radiation therapy. Fatigue may be caused by the cancer or by other conditions, such as anemia or pain. It may also be related to toxic substances that are produced when cancer cells break down and die. During radiation therapy, the child’s body uses more energy to heal itself, so fatigue will not always be relieved by rest. Making daily trips for radiation treatments can also be tiring.

Radiation therapy to any area of the body can make a child feel more tired than usual, but fatigue is more common when larger areas of the body are treated. Anemia is also more likely to occur when the treatment area includes bones where blood cells are formed in the bone marrow, such as the pelvic bones.

Fatigue usually occurs during or after the second week of radiation therapy. The child may have more or worse symptoms of fatigue over the course of treatment. Symptoms include:

  • tiredness
  • feeling exhausted
  • feeling too weak to carry out normal activities
  • drowsiness
  • having trouble concentrating or remembering

Fatigue usually goes away gradually after treatment has ended. Some children continue to feel tired for several weeks or months after radiation therapy.

Find out more about fatigue.

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Sore mouth and throat

A sore throat occurs because rapidly growing cells lining the throat are sensitive to the effects of radiation. They can become inflamed and painful. A sore throat may occur if radiation is given to the neck or upper part of the chest. Symptoms usually appear about 2–3 weeks after radiation therapy begins and often improve a few weeks after treatment is finished.

Find out more about sore mouth and throat.

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Changes in taste

The taste buds are very sensitive to the effects of radiation. Taste changes can occur when radiation therapy to the neck damages salivary glands and the taste buds on the tongue. This damage can affect the way some foods taste or smell. Salty and bitter tastes are usually affected the most. Some foods, such as meat, may start to taste bitter or metallic. These symptoms occur during the first or second week of treatment. Taste usually returns to normal 1–3 months after radiation therapy ends. But sometimes it becomes a long-term problem.

There are many ways to cope with taste changes. Talk to your child’s radiation therapy team or a registered dietitian (a healthcare professional who specializes in food and nutrition). They can suggest ways to help your child deal with taste changes.

Find out more about taste changes.

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Difficult and painful swallowing

Difficult or painful swallowing occurs when the throat or esophagus becomes inflamed and irritated from radiation to the neck or chest area. It usually starts about 2 weeks after treatment begins.

Tell the radiation therapy team if difficult or painful swallowing makes it hard for your child to eat. They can make helpful suggestions. Medicines, such as antacids, may be given to ease the pain caused by an inflamed esophagus. Swallowing should become easier and less painful when treatment is over and the inflammation goes away.

Find out more about difficulty swallowing.

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Heartburn can occur when the lining of the lower esophagus becomes irritated from radiation therapy. Spicy and fried foods, and foods that cause gas, should be avoided. Antacids or other medicines may be needed. Heartburn often goes away after treatment has ended.

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Hoarseness can occur when the larynx, or voice box, becomes irritated and inflamed from radiation therapy. The irritation and inflammation is called laryngitis. Hoarseness usually starts 2–3 weeks after radiation therapy begins. The child’s voice usually returns to normal after treatment ends and the inflammation goes away.

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Nausea and vomiting

Nausea and vomiting are more common if the upper abdomen (including the stomach) is treated with radiation. Children may start to feel nauseous about 1–3 hours after their daily treatment, about 1–2 weeks after treatment begins. These side effects usually go away after treatment is finished.

Tell the radiation therapy team if your child has nausea or vomiting. They can suggest different ways to manage these side effects. Some children find that having a small snack before treatment makes them feel better, while others find it better not to eat. Some children prefer to wait a few hours after treatment before eating. Other children get relief by eating something right after treatment. Nausea and vomiting can also be managed with antinausea medicine.

Find out more about nausea and vomiting.

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Diarrhea is the frequent passing of very loose, watery stools. Radiation therapy to the abdomen or pelvic area can cause diarrhea. It often begins 2–3 weeks after radiation therapy begins. Diarrhea usually goes away once radiation therapy treatments are completed.

Tell the radiation therapy team if your child has diarrhea. They can suggest over-the-counter or prescription medicines to help relieve diarrhea.

Find out more about diarrhea.

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Bone marrow suppression

When radiation therapy is given to large areas of the chest or pelvis, it can affect large amounts of bone marrow. This can cause bone marrow suppression and low blood cell counts.

  • A low white blood cell count is called neutropenia. It increases the risk of infection.
  • A low platelet count is called thrombocytopenia. It increases the risk of bruising and bleeding.
  • A low red blood cell count is called anemia. It causes fatigue, paleness and malaise, which is a general feeling of discomfort or illness.

Low blood cell counts occur because radiation affects the bone marrow, where blood cells are made. Blood cell counts are more likely to be affected if the child is treated with chemotherapy at the same time as radiation therapy. They are also likely to be affected if the bones where many of the blood cells are made lie in the treatment area. These bones include the ribs, breastbone, shoulder bones and pelvis.

Blood counts often begin to recover and rise on their own, usually within 2–4 weeks after treatment. Some children may need medicines or blood transfusions to treat severe problems caused by low blood counts. Cancer treatment may be postponed until blood cell counts return to normal.

Find out more about bone marrow suppression and low blood cell counts.

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Thyroid problems

Thyroid problems can develop if the neck is in the radiation treatment field. Children who receive radiation therapy to the neck area have a higher risk for developing hypothyroidism (lower than normal thyroid function), hyperthyroidism (higher than normal thyroid function) and thyroid nodules.

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Lung problems

The lungs are very sensitive to radiation. Lung problems can occur when the trachea, or windpipe, and bronchi are in the treatment area. The problems include increased cough and mucus in the throat and chest. Other lung problems caused by radiation therapy to the chest can also occur, including radiation pneumonitis and pulmonary fibrosis.

Radiation pneumonitis is inflammation of the lungs caused by radiation therapy. Even low doses of radiation can cause pneumonitis. Radiation pneumonitis is more likely to occur if a large area of one or both lungs is treated with radiation. It sometimes starts during radiation treatment, but it usually occurs about 1–3 months after treatment is finished. It usually lasts 1–2 months. Symptoms of pneumonitis include difficulty breathing or shortness of breath, dry cough, rapid breathing and rapid heartbeat. Find out more about radiation pneumonitis.

Pulmonary fibrosis is scarring or stiffening of the lungs that develops over time with inflammation. Many children do not have any symptoms with pulmonary fibrosis, but some may have shortness of breath and can’t be physically active for long periods of time. Pulmonary fibrosis can occur months or years after radiation therapy. It may become a long-term side effect that gets worse over time.

Tell the radiation team if your child has coughing, difficulty breathing or shortness of breath.

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Heart problems

Heart problems can develop if the heart or area behind the breastbone is in the radiation treatment field. Radiation can damage the heart and cause heart disease. These problems can be late effects of radiation to the chest. The risk and severity of heart problems may be greater if the child is treated with both radiation and chemotherapy.

Radiation to the chest can cause the following heart problems.

Pericarditis is inflammation of the sac that surrounds the heart, which is called the pericardium. Symptoms of pericarditis include fever, difficulty breathing and chest pain. Long-term inflammation of the pericardium could lead to a thickening of the pericardium, fluid buildup within the pericardium (called pericardial effusion) and scar tissue formation. These problems can weaken the heart so it can’t pump as much blood.


Premature coronary artery disease, or heart disease, happens when arteries going into the heart harden or narrow. This can occur if the blood vessels around the heart are scarred and become less flexible. It lowers blood flow and increases the risk for heart attack and stroke.

Myocardial fibrosis is the formation of scar tissue in the heart muscle. It can lower blood flow through the heart.

Scar tissue in the heart valves can cause mitral insufficiency, where the mitral valve doesn’t close tightly and blood can flow back into the heart.

Tell the radiation therapy team if your child has shortness of breath, chest pain or swelling in the arms or legs.

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Spinal cord myelopathy

Spinal cord myelopathy is damage to the myelin sheath that covers the spinal cord. It can occur if the spinal cord is in the treatment field when radiation is given to the chest. It can occur 2–6 months after radiation therapy.

The most common symptom is an electric-shock sensation, which is called Lhermitte’s sign. The sensation begins in the neck or back, usually when the neck is bent forward, and shoots down to the legs. It usually improves without treatment and is not linked with any long-term problems.

Spinal cord myelopathy that occurs months or years after radiation therapy is called late, or delayed, radiation myelopathy. Symptoms include weakness or loss of sensation. Late radiation myelopathy does not usually improve on its own and may result in gradual paralysis.

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