Adult respiratory distress syndrome after limited thoracic radiotherapy

The authors report three patients who developed fatal respiratory failure after limited or unilateral thoracic radiation therapy for neoplasms. The respiratory failure was characteristic of the adult respiratory distress syndrome (ARDS) with refractory hypoxemia and diffuse bilateral infiltrates including areas of lung well outside of the radiation ports. No patient received drugs known to cause lung injury, and cardiogenic edema and infections were excluded. At autopsy the lungs exhibited interstitial fibrosis, Type II alveolar cell hyperplasia, inflammatory infiltrates, and squamous metaplasia. The etiology of the pulmonary injury is unclear.