[Dose distributions of linac-based radiosurgery for pineal region mass]

The doses of linac convergent-beam irradiations to pineal region were measured in an anthropomorphic phantom. The feasibility of a linac accelerator as a radiosurgery tool to treat small sized intracranial masses was evaluated. The influences of some irradiation parameters on the dose distributions were discussed. Linac-based radiosurgery can result in dose distributions similar to those achieved by gamma knife, so it is another safe and effective treatment technique of neurosurgery. The smaller the aperture is and the greater the irradiation arc travel is, the larger the dose gradient will be and the better the dose distribution will be. The maximum target doses are dependent greatly upon the collimater aperture. The appropriate irradiation arc travel and margin isodose were also discussed.