Figure 3.

Primary radiation increases microvascular permeability and plasma proteins that overwhelm the drainage mechanisms. This elicits a secondary response to hyperplasia of type II epithelial cells. In addition, there is an accumulation of pulmonary surfactant within the alveolus that triggers apoptosis of type II epithelial cells, oxidative damage and the release of fibrotic cytokines such as TNF-Υ and TNF-α. Primary radiation increases the catabolism of lipoprotein lipases due to increased glucose and glycerophosphate. This results in the release of fatty acids leading to decreased distensibility and respiratory failure. Figure created in BioRender.com.