An x-ray irradiation system includes a first x-ray tube constructed and arranged to be able to irradiate an object with at least a portion of a first x-ray beam emitted from the first x-ray tube, and a second x-ray tube constructed and arranged to be able to irradiate the object with at least a portion of a second x-ray beam emitted from said second x-ray tube simultaneously with said first x-ray beam. The first and second x-ray tubes are arranged such that the first and second x-ray beams are incident on, and intersect within, the object at respective first and second oblique angles to define a target volume such that a dose rate is substantially uniform as prescribed within said target volume.