Iso-effect tables for tolerance of irradiated normal human tissues.
Available literature on radiation injury to human tissues (lung, brain, kidney and intestine) was surveyed. A parameter search program (RAD3) was used to derive best-fitting cell kinetic parameters, on the assumption that radiation injury arises from depletion of parenchymal cells in the irradiated organs. From these parameters iso-effect tables were constructed for a wide range of treatment schedules, including daily treatment as well as fractionation at longer intervals, for each tissue. The tables provide a set of limiting doses, above which the risk of radiation injury becomes substantial. Tolerance limits and dose-time-factors were substantially different in the four tissues. It is concluded that computed iso-effect tables provide a more reliable guide to treatment than conventional time-dose equations.
D001921:Brain / Q000528:radiation effects*; D006801:Humans; D007422:Intestines / Q000528:radiation effects*; D007668:Kidney / Q000528:radiation effects*; D008168:Lung / Q000528:radiation effects*; D011832:Radiation Injuries / Q000517:prevention & control*; D011836:Radiation Tolerance; D011879:Radiotherapy Dosage / Q000592:standards