Radiation-induced changes in lung tissue and development of fibrosis determined by quantitative morphometric methods.

This study presents results of morphometric investigations of mouse lungs after single irradiation. An automatic image analyser was used to monitor pathological changes in morphological structure, especially the size and distribution of collagen fibres, the thickness of the septa and the diameters of alveoli in the lung. Radiation-induced changes in the area of alveoli and septa as well as collagen content were seen 11 weeks after irradiation. A dose-dependent increase in tissue and decrease in alveolar surface as well as a quantifiable increase in radiation oedema were seen. The septa were thickened and the total collagen content increased in a dose-dependent manner. The morphometric methods used here are suitable for determining changes in lung structure, particularly those in collagen content in the early phase of a pathological response after thorax or total body irradiation for conditioning in bone marrow transplantation.