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Radiation pneumonitis

The lung is very sensitive to the effects of radiation. Radiation pneumonitis is inflammation (not infection) of the lung caused by radiation therapy to the chest. Radiation to the chest can cause the lungs to make less surfactant. Surfactant is a substance that helps keeps the air passages open. If there isn’t enough surfactant, the lungs can’t fully expand.


Radiation pneumonitis is caused by radiation to the chest. It is more likely to occur when:

  • high doses of radiation are used
  • a large area of the lung is treated with radiation
  • certain chemotherapy drugs, such as bleomycin (Blenoxane), cyclophosphamide (Cytoxan, Procytox) or carmustine (BiCNU, BCNU), are given along with radiation

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Symptoms of radiation pneumonitis sometimes start during treatment, but they are more likely to occur about 1–3 months after treatment. Symptoms can include:

  • fever
  • cough
    • The cough may be non-productive (dry) or productive (coughing up mucus or phlegm).
    • The amount of mucus with the cough may increase as treatment continues.
  • chest congestion
  • shortness of breath
  • chest discomfort

Symptoms may go away or continue for several weeks or months, becoming a long-term (chronic) problem.

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Report cough or shortness of breath to the radiation oncologist or radiation therapy team. To cope with symptoms, you can:

  • Pace yourself and plan activities with rest periods, if you feel short of breath.
  • Drink more fluids and use a cool-air vaporizer or humidifier to keep the air moist.
  • Use extra pillows to raise your head and upper body while resting or sleeping.
  • Avoid going outside on hot, humid days or on very cold days. Being outdoors in very hot or cold weather may irritate the lungs.
  • Wear light, loose-fitting tops and avoid anything tight around the neck, such as ties or shirt collars.

Doctors may prescribe medicines to reduce congestion (decongestants), decrease cough (cough suppressants), widen the bronchialbronchialThe large tubes, or airways, that branch off from the windpipe (trachea) into the lungs, where they branch into smaller tubes (bronchioles) that end in the alveoli (air sacs). Bronchi carry air to and from the lungs. tubes (bronchodilators) or reduce inflammation (corticosteroidscorticosteroidsAny steroid hormone that acts as an anti-inflammatory by reducing swelling and lowering the body’s immune response (the immune system’s reaction to the presence of foreign substances).). Oxygen therapy may also be needed.

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