Elekta Ab (publ)

Elekta Instrument Ab

Elekta Instruments Ab

Elekta Ab

Björn Somell

Håkan Nordström

Jens Olof Sjölund

Stella Riad

Marcus Hennix

Fredrik Lundqvist

Karl Danielsson

Pär Lidberg

Joakim Wang Erlandsson

The present invention relates to the field of radiation therapy and methods, software and systems for treatment planning. A target volume of a region of a patient to be treated during a treatment of a patient in a radiation therapy unit is obtained. A first isocenter location procedure is performed including inter alia evaluating potential isocenter locations along normal directions of the surface and respective isodistance surfaces in respective starting voxels in a direction inwards from the surface, and a second isocenter location procedure is performed including inter alia identifying a median axis of the target volume or center point of the target volume, placing isocenters at locations along the median axis, and placing isocenters in the target volume based on a distance to existing isocenters and to the target surface.

Treatment planning

In the field of radiotherapy, methods for dose or treatment planning for a radiotherapy system are disclosed, wherein a spatial dose delivered can be adjusted and delivered radiation is determined using an optimization problem that steers the delivered radiation according to a frame description reflecting criteria for regions of interest that include at least one of targets to be treated during treatment of the patient, organs at risk and/or healthy tissue. The method includes estimating a voxel set receiving a higher dose than a predetermined threshold dose level, which voxel set includes voxels from at least one target volume. Further, a low dose voxel set is determined and a frame description for the voxels in the low dose voxel set is provided where voxels receiving a dose exceeding a predetermined threshold value is penalized such that the dose delivered to the low dose voxel set is suppressed. The frame description is then used in the optimization problem that steers the delivered radiation.

Methods for inverse planning

A method and a dose planning module for planning a treatment session of a patient by means of a radiation therapy system includes a radiation therapy unit having a fixed radiation focus point. The method includes obtaining a target volume of a region of a patient to be treated during a treatment of a patient in a radiation therapy unit, the target volume being modeled as a three-dimensional voxel representation; selecting an isodose level for the planned treatment; determining shots to be delivered during the treatment, each shot being modeled by a spatial dose volume distribution of radiation represented by a three-dimensional voxel representation, the shape of the spatial distribution depending on the specific collimator setting and the selected isodose level; and selecting shots in a decreasing volume order for the dose planning.

Effective volume filling with templates

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Stockholm, Sweden

Björn Somell