Radiobiological effects and dose-LET spectra.

To advance our knowledge about radiobiological cell effects typical different cell reactions must be discriminated and studied individually. Today the 2-component theory which distinguishes between repairable beta-reactions and nonrepairable alpha-reactions, is the first step on this road. Such specialized investigations give a more detailed and clearer picture of the cell reactions than the usual RBE comparisons carried out with different radiation types. This is especially important for clinical radiotherapy where it is essential to increase the selectivity between reactions on normal and tumor cells. alpha-values for different types of radiation are communicated.