[Radiation tolerance of normal lung-pulmonary radiation syndrome]

Radiation pneumonitis and radiation fibrosis are two distinct syndromes with probably different target cells. The ultrastructural changes occur rapidly and current evidence suggests that damage to the type II pneumocyte and the endothelial cell is linked to the pneumonia process than the fibrotic. The fibrosis process may be related to the basement membrane of both endothelial cells and alveolar type I cells. Dose time and volume data for tolerance dose are well documented in animals. Many antineoplastic agents enhances radiation lung damage. The pneumonitis and fibrosis will be discussed.