A unified approach to dose-effect relationships in radiotherapy. I: Modified TDF and linear quadratic equations

A linear quadratic factor analogue (LQF) to the variable-exponent TDF model is introduced. In both of these models, account is taken of the volume of tissue irradiated. Scaling factors are used such that an LQF or a TDF of 100 represents tolerance for each volume or partial volume of each tissue or organ irradiated. These models are sufficient for tissues which are irradiated fairly homogeneously. Examples illustrate the use of these models.