APPARATUS AND METHOD FOR RADIATION THERAPY WHERE THE COLLIMATORHELMET COMPRISES SLIDABLE PLATES FOR CONTROLLING THE COLLIMATOR OPENINGS

摘要

A radiation therapy device and a method of changing the spatial dose distribution surrounding a focus are disclosed. A subset of radioactive sources in a source carrier arrangement is displaceable relatively to collimator passage inlets, while the rest of the sources are fixed relativel y to said collimator passage inlets.