pneumonitis, radiation

pneumonitis, radiation Inflammation of the lungs that results from radiation. Radiation pneumonitis typically occurs after radiation treatments for cancer within the chest or breast. Radiation pneumonitis usually manifests itself 2 weeks to 6 months after completion of radiation therapy. Symptoms include shortness of breath upon activity, cough, and fever. If radiation pneumonitis persists, it can lead to scarring of the lungs, referred to as radiation fibrosis. See also fibrosis, radiation.