radiation pneumonitis

pneumonitis [noo″mo-ni´tis]

inflammation of the lung; see also pneumonia.

hypersensitivity pneumonitis a respiratory hypersensitivity reaction to repeated inhalation of organic particles, usually in an occupational setting, with onset a few hours after exposure to the allergen. Many different substances are potential causes of the condition; see bagassosis, farmer's lung, and pigeon breeder's lung. Characteristics include fever, fatigue, chills, unproductive cough, tachycardia, and tachypnea; in the chronic form there is interstitial fibrosis with collagenous thickening of the alveolar septa. Called also extrinsic allergic alveolitis.

radiation pneumonitis lung inflammation resulting from radiation exposure, usually radiation therapy, with coughing, dyspnea, and alveolar infiltration of secretions, leading to mild to severe or even fatal fibrosis 6 to 9 months after the exposure.

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radiation pneumonitis

Irradiation pneumonitis Pulmonology A condition caused by exposure of lung tissue to radiation, a common complication of RT to mediastinal and thoracic tumors–eg, NHLs, Hodgkin's disease, breast and esophageal CAs; frequency of RP reflects dose and amount of tissue exposed to radiation Incidence RP occurs in 65% of irradiated lung fields; clinical pneumonitis occurs in 6%, 2% die from RP. See Radiation fibrosis.