Abstract: A method and associated system 300 for delivering intensity-modulated radiation therapy (IMRT) uses variable feathering field splitting for intensity modulated fields of large size. A processor controls a beam-shaping device that splits the radiation beam into a plurality of radiation fields delivered to a patient. The processor in cooperation with the beam-shaping device implements a variable feathering method which includes providing an intensity matrix for the treatment of a patient, the intensity matrix having a plurality of rows and columns for spanning a prescribed radiation field including a prescribed field width. The prescribed width is compared to a maximum field width provided by the radiation treatment system.

Abstract: A method and associated system 300 for delivering intensity-modulated radiation therapy (IMRT) uses variable feathering field splitting for intensity modulated fields of large size. Processor 112 controls a beam-shaping device 106 so that the beam-shaping device splits the radiation beam into a plurality of radiation fields delivered to the patient 102. Processor 112 in cooperation with beam-shaping device 106 implements a variable feathering method which includes the steps of providing an intensity matrix for the treatment of a patient, the intensity matrix having a plurality of rows and columns for spanning a prescribed radiation field including a prescribed field width. The prescribed width is compared to a maximum field width provided by the radiation treatment system. The intensity matrix is split into a plurality of spatially overlapping intensity submatrices when the prescribed width exceeds the maximum field width, wherein the splitting comprises variably feathering the intensity matrix.

Abstract: A method of delivering intensity modulated radiation therapy (IMRT) is disclosed. An intensity profile for the treatment of a patient is provided which spans a prescribed field width and includes a discrete profile having intensity values at each of a plurality of sample points bounded by the prescribed width. The prescribed width is compared to a maximum field width provided by the radiation treatment system. The intensity profile is split into a plurality of intensity profile portions, each having respective widths less than the maximum width if the prescribed width is greater than the maximum width. The prescribed field is also divided into a plurality of different profile portion split arrangements. A monitor unit (MU) efficiency is calculated for each of the arrangements. One of the arrangements is selected for delivery by the system using a leaf sequencing method.

Abstract: A method of delivering radiation treatment using multi-leaf collimation includes the step of providing a radiation fluence map which includes an intensity profile. The fluence map is converted into a preliminary leaf sequence, wherein the preliminary leaf sequence minimizes machine on-time and is generated without leaf movement constraints. The leaf movement constraint is imposed on the preliminary leaf sequence. At least one constraint elimination algorithm is then applied, the algorithm adjusting the preliminary leaf sequence to minimize violations of the constraint while providing the desired fluence map and minimized radiation on-time. The method can be applied to SMLC and DLMC systems, and can include adjustment for the tongue-and-groove effect.

Abstract: A method of delivering intensity modulated radiation therapy (IMRT) is disclosed. An intensity profile for the treatment of a patient is provided which spans a prescribed field width and includes a discrete profile having intensity values at each of a plurality of sample points bounded by the prescribed width. The prescribed width is compared to a maximum field width provided by the radiation treatment system. The intensity profile is split into a plurality of intensity profile portions, each having respective widths less than the maximum width if the prescribed width is greater than the maximum width. The prescribed field is also divided into a plurality of different profile portion split arrangements. A monitor unit (MU) efficiency is calculated for each of the arrangements. One of the arrangements is selected for delivery by the system using a leaf sequencing method.

Abstract: A method of delivering radiation treatment using multi-leaf collimation includes the step of providing a radiation fluence map which includes an intensity profile. The fluence map is converted into a preliminary leaf sequence, wherein the preliminary leaf sequence minimizes machine on-time and is generated without leaf movement constraints. The leaf movement constraint is imposed on the preliminary leaf sequence. At least one constraint elimination algorithm is then applied, the algorithm adjusting the preliminary leaf sequence to minimize violations of the constraint while providing the desired fluence map and minimized radiation on-time. The method can be applied to SMLC and DLMC systems, and can include adjustment for the tongue-and-groove effect.