Cell population kinetics and dose-time relationships for post-irradiation injury of the brachial plexus in man.

Collected data on radiation-induced lesions of the brachial plexus were analyzed on the assumption that this reaction arises from depletion of some unidentified cell population in the irradiated tissues. A multi-probit search program was used to derive best-fitting cell kinetic parameters in a composite multi-target model for cellular radiation lethality and repopulation. From these parameters, a comprehensive iso-effect table, for a wide range of treatment schedules including daily treatment as well as fractionation at shorter and longer intervals, was constructed. The table provides a useful set of tolerance dosage limits for late effects in irradiated peripheral nerve.