Patent Number: 060524359
Section: abstract

A system and method for radiation therapy delivery. Prior to the delivery of the actual treatment, a run up is executed in order to stabilize the RF system. The run up is accomplished by initiating the triggers with the injector and RF pulses out of phase so that the electrons, for example, in the accelerating waveguide do not get accelerated even though the RF system is being pulsed. The RF warm up period during which the injector and RF pulses are out of phase, ends at RAD ON (Radiation On) with the injector pulse being phase-shifted to coincide in time with the RF pulse thereby resulting in the production of electron beam pulses. Following the application of this run up period, precise and rapid disabling and enabling of the treatment beam between IMRT fields can be accomplished. The electron injection is phase-shifted in and out without affecting either the injector or the RF pulse amplitudes, thereby allowing transitions between a stable RAD ON beam and no beam between one pulse and the next.