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Radiation Pneumonitis


Updated June 09, 2014

Senior with Chest Pain
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Radiation pneumonitis is an inflammation of the lungs due to radiation therapy. This side effect of radiation therapy occurs in 5 to 15% of people who go through radiation therapy for lung cancer, but can also result from radiation to the chest for breast cancer, lymphomas, or other cancers.

Symptoms most commonly occur between 1 and 6 months after completing radiation therapy. The risk of developing this complication depends on the dose of radiation used and the amount of tissue treated. It is more common if chemotherapy is given at the same time as radiation therapy, and is more likely to occur if you have other lung diseases, such as COPD. With treatment, most people recover without any lasting effects.


It is important to be aware of radiation pneumonitis, because symptoms can be very similar to those caused by lung cancer alone, or can be mistaken for an infection such as pneumonia.

Common symptoms include:

  • Shortness of breath that is usually more notable with exercise
  • Chest pain, especially that which worsens with breathing
  • Cough
  • Low-grade fever
In some cases, no symptoms are present, and the diagnosis is made by its appearance on a chest x-ray alone.


Lab tests may show signs of inflammation, such as an increased white blood cell count. Results of a test that looks for inflammation, called a sed rate, may show non-specific elevations above normal. A chest x-ray can show the characteristic appearance of radiation pneumonitis and may suggest that you need to be treated, even if you are not having any symptoms.


Treatment is aimed at decreasing the inflammation. Steroids, such as prednisone, are given until the inflammation subsides and then slowly decreased over time.


Radiation pneumonitis usually resolves with treatment. If it goes untreated or persists, it can lead to pulmonary fibrosis (scarring of the lungs), which is often permanent.


Chang, J. et al. Risk factors for radiation pneumonitis in lung cancer. Journal of Clinical Oncology. 2008 ASCO Annual Meeting Proceedings. 26, No 15S(May 20 Supplement):7573.

Kong, F. et al. Non-small cell lung cancer therapy-related pulmonary toxicity: an update on radiation pneumonitis and pulmonary fibrosis. Seminars in Oncology. 2005. 32(2 Suppl 3):S42-54.

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