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Non-Hodgkin lymphoma

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Potential side effects of radiation therapy for non-Hodgkin lymphoma

Side effects can occur with any type of treatment for non-Hodgkin lymphoma (NHL), but not everyone has them or experiences them in the same way. Side effects of radiation therapy will depend mainly on:

  • the size of the area being treated
  • the specific area or organs being treated
  • the total dose
  • the treatment schedule
  • if other treatments, such as chemotherapy, are also being given

Radiation therapy damages cancer cells, but healthy cells in the treatment area can also be damaged, even though steps are taken to protect them as much as possible. Different cells and tissues in the body tolerate radiation differently.

Side effects can happen any time during radiation therapy. Some may happen during, immediately after or a few days or weeks after radiation therapy. Most side effects go away after radiation therapy is over. However, some side effects may persist for a while because it takes time for healthy cells to recover from the effects of radiation therapy. Late side effects can occur months or years after radiation therapy. Some side effects may last a long time or be permanent.

It is important to report side effects to the healthcare team. Many side effects can be relieved by medications, a change in diet or by other measures. Doctors may also grade (measure) how severe certain side effects are. Sometimes radiation therapy treatments need to be adjusted if side effects are severe.

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 become red, dry, itchy or flaky. Most skin reactions occur within the first 2 weeks of receiving radiation treatment. They usually go away a few weeks after treatment, but some skin changes, like darkening, can be permanent. Some people do not experience any skin reactions with radiation therapy.

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

Radiation therapy to any area of the body can make a person feel more tired than usual, but fatigue is more common when larger areas of the body are treated for NHL. Anemia is 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 the second week of radiation treatment or later. Symptoms of fatigue may increase or become more severe over the course of treatment. Fatigue usually goes away gradually after treatment has ended, but some people continue to feel tired for several weeks or months after radiation therapy.

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Sore throat and painful swallowing

Radiation therapy to the neck and chest area to treat NHL can cause a dry, sore throat or painful swallowing. It can also cause some foods to taste different than normal. A sore throat and painful swallowing can occur because the membranes lining the throat and esophagus become irritated if they are in the radiation treatment area. Painful or difficult swallowing can also lead to problems with eating. Symptoms usually start 2–3 weeks after radiation treatment starts. This problem often goes away when treatment has ended.

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Taste changes

Taste changes can occur when radiation therapy to the neck damages the salivary glands and taste buds on the tongue, which can affect the way some foods taste or smell. The taste buds are very sensitive to the effects of radiation and symptoms often occur early, usually during the first and second week of treatment. Taste may return to normal 1–3 months after radiation treatment is finished.


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Nausea and vomiting

Radiation therapy to the upper abdomen can cause an upset stomach and nausea and vomiting. These side effects are more common when a larger area of the upper abdomen is radiated to treat NHL. People may start to feel nauseated about 1–3 hours after their daily treatment (about 1–2 weeks into therapy). The nausea tends to last but is less intense as treatment progresses. Nausea and vomiting usually go away after treatment is finished.

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Diarrhea is an increase in the number and looseness of stools. Radiation therapy to the abdomen or pelvic area to treat NHL can cause diarrhea. Diarrhea often begins 2–3 weeks into radiation therapy. Diarrhea usually goes away once radiation therapy treatments are completed.

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Bone marrow suppression

Bone marrow suppression and decreased blood counts can occur when radiation therapy is given to large areas of the chest or pelvis and considerable amounts of bone marrow are affected. Bone marrow suppression is more likely to occur if chemotherapy is given at the same time or right before radiation therapy to treat NHL. Bone marrow suppression can result in:

  • infection caused by low white blood cell count (neutropenia)
  • bruising and bleeding caused by low platelet count (thrombocytopenia)
  • fatigue, paleness and malaisemalaiseA general feeling of discomfort or illness. caused by low red blood cell count (anemia)

Blood counts often begin to recover and rise on their own, usually within 2–4 weeks after treatment. Sometimes medications or blood transfusions are needed to treat severe problems caused by low blood counts. Drops in blood cell counts may require that cancer treatment is postponed until blood counts recover.

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Dental cavities

There is an increased risk for dental cavities after treatment for NHL if radiation therapy is given to the head or neck area. Radiation may affect the salivary glands and the production of saliva. This depends on the dose of radiation used and the number of salivary glands radiated. Less saliva in the mouth can lead to an increase in dental cavities (caries) and gum disease. Tooth pain, tooth decay and swollen, painful gums can result.

Measures should be taken to prevent or decrease the severity of dental cavities, including:

  • a complete dental checkup, cleaning and filling of cavities before treatment begins
  • good daily oral hygiene and fluoride treatments during and after treatment
  • regular visits to the dentist after treatment for dental checkups, cleaning and treatment of any problems

The person needs to continue to take good care of their teeth and gums to help prevent tooth decay.

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Thyroid problems

Radiation to the neck area to treat NHL can cause hypothyroidism (a decrease in thyroid function). The thyroid gland makes hormones that help regulate and maintain many body functions. Symptoms of hypothyroidism include fatigue, hair loss, brittle nails, dry skin or changes in menstruation in women.

Hypothyroidism usually develops 3–4 years after treatment, but can also occur several years later.

Thyroid function is checked and daily medications (thyroid hormone replacement) may be needed to regulate the thyroid gland.

Problems with thyroid function are often permanent.

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Fertility problems

When radiation therapy is given to the pelvis to treat NHL, it may affect fertility. The reproductive organs may be affected by radiation therapy, depending on the dose of radiation therapy given. Women may experience premature menopause or infertility if the ovaries receive radiation. Men may have reduced or stopped sperm production during therapy if the testicles receive radiation. Depending on the dose received, this may result in infertility. When possible, measures are taken to shield or protect the reproductive organs from radiation as long as the NHL can still be adequately treated. This can help the person maintain their fertility.

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Heart and lung problems

High doses of radiation therapy to the chest to treat NHL can cause heart and lung problems. Lung problems can occur if the trachea and bronchi are in the treatment area and become irritated by radiation therapy. Lung problems sometimes start during radiation treatment, but usually occur a few months or more after treatment is completed.

Heart problems are not very common with radiation therapy to the chest, but they can occur as a late problem. Heart problems may occur if the treatment area includes the heart and mediastinummediastinumThe space in the chest between the lungs, breastbone and spine that contains the heart, great blood vessels, thymus, trachea (windpipe), esophagus and lymph nodes., and especially if anthracycline chemotherapy drugs are also given to treat NHL.

Heart and lung problems can be managed, but are often long-standing problems.

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Cognitive problems

Radiation therapy to the brain to treat certain types of lymphoma that can affect the brain, such as primary CNS lymphoma (PCNSL), can cause changes in cognitive functioning and other neurologic problems. These are more likely to occur after treatment and are often long-standing problems.

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Second cancers

There is a small risk that young women who had radiation therapy to the chest to treat their NHL can later develop breast cancer. The risk for breast cancer depends on the age of the woman when she received radiation therapy and if chemotherapy was also given. The benefit of treating the lymphoma usually far outweighs the risk of developing a second cancer from radiation therapy treatment.

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