US Patent 7188999 Radiation treatment apparatus

A radiation treatment apparatus includes a guide and a support member. The guide moves a radiation generating unit along an orbit with a predetermined radius such that an X-ray emitted from the radiation generating unit may cross an isocenter. The support member rotates the guide about a turning axis passing through the isocenter. The radiation generating unit is moved along a spherical plane by the guide and the support member and applies the X-ray toward the isocenter in multiple directions.