various embodiments relate to a method of performing microbeam radiation therapy on a subject , including : producing a high - energy radiation beam in a first direction ; producing planar microbeams using the high - energy radiation beam in the first direction , wherein the microbeams have a width , wherein the planar microbeams produce scattered electrons ; and applying a magnetic field in a direction lying in a plane substantially parallel to the planar microbeams , wherein the strength of the magnetic field corresponds to the width of the microbeam .