Unusual radiologic findings in the thorax after radiation therapy

Radiation therapy is used to treat many intrathoracic and chest wall malign ancies. A variety of changes may occur after radiation therapy to the thora x. Radiation therapy produces dramatic effects in the lung. Pulmonary necro sis is an uncommon, severe, late complication of adjuvant postoperative rad iation therapy. Bronchiolitis obliterans with organizing pneumonia is a dis tinct clinicopathologic entity characterized by patchy, migratory, peripher al air-space infiltrates. Radiation therapy can also cause spontaneous pneu mothorax, mesothelioma, and lung cancer. In the mediastinum, radiation ther apy may cause thymic cysts, calcified lymph nodes, and esophageal injuries. Cardiovascular complications of radiation therapy are often delayed and in sidious. Premature coronary artery stenosis occurs after radiation therapy to the mediastinum. Radiation therapy may also give rise to calcifications of the ascending aorta, pericardial disease, valvular injuries, and conduct ion abnormalities. Women who undergo thoracic irradiation before the age of 30 years have a high risk of developing a second breast cancer. Radiation- induced sarcomas are an infrequent bur: well-recognized complication of rad iation therapy. Other chest wall injuries due to radiation therapy are oste ochondroma and rib or clavicle fractures. Knowledge of the imaging features of injuries caused by radiation therapy can prevent misinterpretation as r ecurrent tumor and may facilitate further treatment.