Abstract: A method for dose-gradient based optimization of an intensity modulated radiation therapy plan. First, an optimizer (6) performs a first optimization (40) of the plan to generate dose distributions corresponding to the plan. Next, the optimizer (6) generates a beam specific dose gradient map (42) for each beam of the plan. Then, new dose gradients are specified (44) for the plan. Last, the optimizer (6) performs a final optimization (46) using the new dose gradients. The final optimization is given the new dose gradients as soft constraints into an objective function. The optimizer (3) applies a limiting factor to the objective function such that a first dose gradient is limited by the optimizer only if the first dose gradient exceeds the new dose gradient for a specific beamlet.

Abstract: The invention relates to a method of selecting a set of beam geometries for use in radiation therapy. The method (10) comprises providing (12) a plurality of candidate beam geometries; optimizing (1) a radiation treatment plan with all candidate beam geometries; and computing (14) a cost function value based on all candidate beam geometries. A first beam geometry from the plurality of candidate beam geometries is removed (15) and a first modified cost function value based on the candidate beam geometries without the removed first beam geometry computed (16). The first beam geometry is restored (17). The steps of removing a beam geometry, computing of a modified cost function value and restoring of the removed beam geometry are repeated (R) for all other candidate beam geometries. One or more beam geometries from the plurality of candidate beam geometries based on the modified cost function values are chosen (19).

Abstract: A therapy planning system (18) and method generate an optimal treatment plan. A plurality of objectives are automatically formulated (154) based on a plurality of clinical goals including dose profiles and priorities. The dose profiles and the priorities correspond to a plurality of structures including a plurality of target and/or critical structures identified within a planning image. Further, a plurality of treatment plan parameters are optimized (156) based on the plurality of objectives to generate a treatment plan. The plurality of objectives are reformulated (162) and the plurality of treatment plan parameters are reoptimized (156) based on the reformulated plurality of objectives to generate a reoptimized treatment plan. The optimizing (156) is repeated based on the reformulated plurality of objectives to generate a reformulated treatment plan.

Abstract: A method and related system to adjust an existing treatment plan. A second optimization is run based on a dual objective function system that includes a first objective function used for the optimization in respect of the existing plan and a second, extended objective function that includes the said first objective function as a functional component.

Abstract: A method for dose-gradient based optimization of an intensity modulated radiation therapy plan. First, an optimizer (6) performs a first optimization (40) of the plan to generate dose distributions corresponding to the plan. Next, the optimizer (6) generates a beam specific dose gradient map (42) for each beam of the plan. Then, new dose gradients are specified (44) for the plan. Last, the optimizer (6) performs a final optimization (46) using the new dose gradients. The final optimization is given the new dose gradients as soft constraints into an objective function. The optimizer (3) applies a limiting factor to the objective function such that a first dose gradient is limited by the optimizer only if the first dose gradient exceeds the new dose gradient for a specific beamlet.

Abstract: A method for reviewing a treatment plan (24) for delivering radiation therapy to a patient. The treatment plan (24) includes geometric analysis data, dose distribution analysis data, dose volume histogram data, parametric analysis data or deliverability analysis data of a patient. First, for the treatment plan (24), a plurality of clinical and delivery goals are identified (20, 22). Next, goal data points are extracted (26) from the treatment plan (24). Then, data points are correlated (28) to identify deficiencies in the treatment plan (24). A report is generated (30) to display on a display (10) the correlated data points using visual markings (84) to highlight identified deficiencies. Text and audio notations can be attached to the report to explain the correlations and warn a user of plan deficiencies.

Abstract: The invention relates to an apparatus for determining a number of beams in IMRT. An objective function providing unit (13) provides an objective function of an IMRT procedure, wherein the objective function depends on a target dose to be applied during the IMRT procedure. A sensitivity determination unit (14) determines the sensitivity of the objective function with respect to changes of the target dose, and a beam number determination unit (15) determines the number of beams depending on the determined sensitivity. It has been found that the sensitivity of the objective function with respect to changes of the target dose is an accurate measure for reliably determining an optimized number of beams in IMRT, which allows for generating a high quality treatment plan and which in turn leads to an improved IMRT procedure.

Abstract: A therapy planning system (18) and method generate an optimal treatment plan. A plurality of objectives are automatically formulated (154) based on a plurality of clinical goals including dose profiles and priorities. The dose profiles and the priorities correspond to a plurality of structures including a plurality of target and/or critical structures identified within a planning image. Further, a plurality of treatment plan parameters are optimized (156) based on the plurality of objectives to generate a treatment plan. The plurality of objectives are reformulated (162) and the plurality of treatment plan parameters are reoptimized (156) based on the reformulated plurality of objectives to generate a reoptimized treatment plan. The optimizing (156) is repeated based on the reformulated plurality of objectives to generate a reformulated treatment plan.

Abstract: A therapy planning system and method generate an optimal treatment plan accounting for changes in anatomy. Therapy is delivered to the subject according to a first auto-planned optimal treatment plan based on a first image of a subject. A second image of the subject is received after a period of time. The second image is registered with the first image to generate a deformation map accounting for physiological changes. The second image is segmented into regions of interest using the deformation map. A mapped delivered dose is computed for each region of interest using the dose delivery goals and the deformation map. The first treatment plan is merged with the segmented regions of the second image and the mapped delivered dose during optimization.