Radiation-induced lung injury.
Radiation therapy (RT) for thoracic-region tumors often causes lung injury. The incidence of lung toxicity depends on the method of assessment (eg, radiographs, patient's symptoms, or functional endpoints such as pulmonary function tests). Three-dimensional (3D) treatment planning tools provide dosimetric predictors for the risk of symptomatic RT-induced lung injury and allow for beams to be selected to minimize these risks. A variety of cytokines have been implicated as indicators/mediators of lung injury. Recent work suggests that injury-associated tissue hypoxia perpetuates further injury. Sophisticated planning/delivery methods, such as intensity modulation, plus radioprotectors such as amifostine, hold promise to reduce the incidence of RT-induced lung injury.