Convex inverse planning method

A treatment planning computer structure integrated into a radiation therapy system having a collimator body provided with several groups or sets of collimator passages, each set being designed to provide a radiation beam of a respective specified cross-section toward a fixed focus, said treatment planning computer structure comprising

• a calculation module configured for generating radiation dose profiles to be delivered to a target, for providing a convex optimization problem that steers the delivered radiation according to clinical criteria objectives for optimizing the delivered radiation based on the clinical criteria objectives, wherein different objectives are set for different regions, and for calculating dose profiles for specific treatment configurations including beam shape settings for the radiation dose profiles calculated using a convex optimization function;
• a treatment plan module configured for creating treatment plans including determining the radiation dose profiles to be delivered during treatment based on treatment configurations, wherein each radiation dose profile is modelled by a spatial dose volume distribution of radiation, the shape of the spatial distribution depending on the beam shape settings;
• and
• an optimizing module configured for selecting an optimal treatment plan that satisfies the clinical criteria,
• wherein a radiation dose plan is generated for delivery to the target through the collimator body according to the selected optimal treatment plan.

A method for treatment planning for a radiation therapy system, wherein the method is for treatment planning for a radiation therapy system, the radiation therapy system comprising a radiation therapy unit having a fixed radiation focus point, wherein a spatial dose distribution surrounding the focus point can be changed by adjusting beam shape setting, including collimator settings for a collimator, said collimator being arranged in sectors and having a plurality of collimator passage inlets directing radiation emanating from radioactive sources of a source carrier arrangement of the therapy system to said focus point, said method further comprising the steps of:

• generating non-uniformly spaced isocenter positions in said target volume;
• choosing isocenter positions of the generated fixed isocenter positions for subsequent optimization, wherein each chosen isocenter position represent a subset of the generated isocenter positions;
• setting a number of objectives reflecting clinical criteria for the regions of interest, wherein different objectives are set for different regions including targets to be treated during treatment of the patient, organs at risk and/or healthy tissue;
• providing a convex optimization problem that steers the delivered radiation according to the objectives;
• calculating dose rates for specific treatment configurations including sector and collimator settings and irradiation time for the chosen isocenters using said convex optimization problem;
• creating treatment plans including determining shots to be delivered during treatment based on the treatment configurations, wherein each shot is modelled by a spatial dose volume distribution of radiation, the shape of said spatial distribution depending on the specific sector and collimator setting and irradiation time;
• selecting an optimal treatment plan that satisfies the clinical criteria;
• generating an optimized dose plan based on the selected optimal treatment plan and transferring the optimized dose plan to the radiation therapy system for use in the treatment of a patient.