Dose-time investigations of radiogenic pneumonopathy. 4

Concerning age dependence and inhomogeneity in 60 young pigs (20 - 25 kg body weight) the hydroxyproline (HP) content of irradiated pulmonary tissue was related to a fit reference value of the untreated tissue and used as quotient for the examination of the radiogenic lung reaction. The right lungs of the pigs were 60Co-irradiated with different single doses in 5 or 15 fractions and with a total irradiation time of 15, 23 and 35 days, resp. The biochemical parameter showed a statistically reliable dose-response relationship and revealed the careful effect of a more frequent fractionation with the total dose unchanged. The extension of the total treatment time, however, produced no essential reduction of collagen formation. The quantification of the pathomorphological findings correlated very well with the results of HP determination. In connection with clinical, radiographic and pathomorphological results the HP content proved to be a useful parameter in quantitative examination of radiogenic pneumonopathy