Comparative analysis of mathematical models describing radiobiological processes in radiotherapy

The concept of biologically effective dose (BED) is widely used to compare the efficacies of different fractionation regimens and to evaluate the responses of normal tissues in radiotherapy, while models describing tumor control probability (TCP) can also be used. The work reported here included comparative analysis of several fractionation regimens using BED and TCP models. The BED model is shown not to take account of uncertainty in the radiobiological parameter α/β, i.e., the level of coverage of tumor volume by the absorbed dose; this prevents appropriate decisions on selection of treatment regimens from being made using only the concept of BED, while the TCP model allows these parameters to be taken into account.