Patent ID: 7295649

Claim:
A method of using a radiation therapy system comprising a multileaf collimator to provide treatment while accounting for unevenness in the intensity distribution of the beam of the radiation therapy system, comprising, obtaining a map of the unevenness in the intensity distribution of the beam of the radiation therapy system in the proximity of a treatment area at at least one beam energy level, developing a treatment plan comprising irradiating one or more selected portions of the treatment area with a calculated radiation dose, positioning the leaves of the multileaf collimator and emitting radiation to selectively irradiate said selected portions of the treatment area, such that the calculated radiation dose is delivered to each selected portion based on said map and said treatment plan wherein said treatment plan comprises irradiating different portions of the treatment area with different beam energy levels, and wherein the step of irradiating different portions of the treatment area with different beam energies comprises continuously varying the energy of the beam.