The bipartition model is used to speed up calculations up to 100 times faster than modern Monte Carlo codes. For accurate dose computation in electron therapy, a good description of the pro-perties of the incoming beam is necessary. These properties can be summarized as the distributions of electrons, incident at the patient surface, with respect to energy, angular deviations, and fluence intensity. Some photons are also generated in the collimators that also need to be included for high precision planning of radiotherapy. The use of accurate radiobiological models is the only feasible way to achieve a major increase in complication free tumor control.
Any cerebral structure is accessible by radiosurgery without risk of hemorrhage or infection.
Prior to the irradiation, the treatment is pre-planned by means of dose distributions calculated individually for each case. Considering the small volumes to be treated and the delicate structures adjacent to these target volumes it is critically important that the hypothetical dose distribution on which the treatment is based also is realized. Fundamentally for correct dose calculations is a correct description of the charac-teristics of the narrow photon beams used in radiosurgery. There are a number of beam characteristics, which are specific for the narrow photon beams. These characteristics impose special requirements on the detectors used to measure the beam as well on the interpretation of the obtained data.