Biological optimization of the dose in stereotactic radiotherapy of brain tumors

The techniques of radiotherapy with a high dose gradient require several demanding choices but represent a major innovation in the radiation therapy of brain tumors. To optimize the expected outcomes in terms of effectiveness and efficacy some recent acquisitions of biological parameters of integration of the linear-quadratic model are illustrated, aimed at the progressive understanding of the role of histology, dose fractionation, timing, toxicity and combined modality therapy.