X-ray pixel beam array systems and methods for electronically shaping radiation fields and modulating radiation field intensity patterns for radiotherapy are disclosed. One exemplary pre-clinical system may include addressable electron field emitters (102, 104) that are operable to emit a plurality of electron pixel beams (106, 108, 110). Each electron pixel beam may correspond to an x-ray target (124) and x-ray pixel beam collimation aperture (136, 138) to convert a portion of energy associated with the electron pixel beam to a corresponding x-ray pixel beam (140, 142). Further, the x-ray pixel beam array collimator (130) forms a one-to-one correspondence between individual electron pixel beam and its corresponding x-ray pixel beam. One exemplary clinical system may include a high-energy electron source (1203), an n-stage scanning system (1210), x-ray pixel beam targets (1212), and an x-ray pixel beam array collimator (1214). A controller (1206) may sequentially direct electron beam pulses to predetermined x-ray pixel targets and produce an electronically controlled radiation field direction, pattern; and intensity pattern.