Abstract: A method of evaluating a radiation therapy (RT) treatment plan for a treatment volume, divided into sub-volumes and having a target volume and one or more organs at risk, OAR. It includes obtaining a RT treatment plan; calculating the linear energy transfer, LET, in each sub-volume; dividing the dose distribution into doses of a first category and a second category in each sub-volume, wherein the first category comprises doses with energy depositions with an LET below a first LET threshold and the second category comprises doses with energy depositions with an LET above a second LET threshold; determining amounts of doses of the first and of the second category in each sub-volume; and performing an analysis of the quality of the RT treatment plan by metrics based on the obtained distribution of doses of the first and of the second category in the target volume and in the OAR.

Abstract: A radiotherapy treatment plan for grid therapy in which a patient is radiated from a source of radiation with a set of spatially fractionated beams of charged particles such as protons, including varying the direction of each beam in the set of beams. Generating the plan comprises the steps of determining a first path through the patient to a first Bragg peak position and determining a second path through the patient, at least a part of the second path being directed at an angle from the first path to a first deflected Bragg peak position. The beam directions may be varied by means of magnetic fields or by varying the relative angle between the gantry and the patient.

Abstract: The trajectory of a beam of charged particles within a patient may be changed by the application of a magnetic field. In that way, the position of the beam's Bragg peak may be controlled for a beam having a specific direction and energy.

Abstract: A method is proposed for evaluating the robustness of a radiotherapy treatment plan. The method comprises, defining a number of scenarios, each comprising one or more errors for each fraction of the plan, including interfractional and/or intrafractional errors, and calculating a dose distribution resulting from the scenario; The robustness of the plan is then evaluated based at least one of the following i. the probability of fulfilling a set of clinical goals estimated as the clinical goal fulfilment over the scenarios ii. the range of DVH values over the scenarios iii. dose statistics for dose distributions defined as voxel-wise aggregates over the scenario doses.

Abstract: Better Pareto dose distributions for multi-criteria optimization of treatment plans can be obtained by obtaining at least one reference dose function designed to result in an acceptable reference dose distribution, defining a multi-criteria optimization problem including the at least one reference dose function as at least one optimization function, performing at least two optimization procedures based on the multi-criteria optimization problem to generate a set of at least two possible treatment plans, obtaining a treatment plan to be used for treating the patient, based on the set of possible treatment plans, by selecting one plan or by combining plans.

Abstract: A method of radiotherapy treatment planning for creating a plan for delivery of radiation to a patient in at least one particle-based arc is proposed. The delivery time for the plan is reduced by including a penalty in the objective function, designed to limit the number of energy layers and/or the number of energy layer changes.

Abstract: A method for ion based radiation therapy treatment planning for avoiding dose delivery to a distal risk organ, said risk organ being located after the target seen from a first beam angle, the method comprising defining an optimization function comprising at least one objective function related to at least one desired property of the treatment plan, wherein the objective function is related to limiting a parameter ? defining the fraction of the total number ?OAR of ions that reach the risk organ relative to the total number ?a of ions. In addition, one can assume a different density when calculating ? which will result in a plan that is more robust with respect to density perturbations.

Abstract: A method of optimizing a radiotherapy treatment plan is disclosed, comprising the steps of: a. obtaining a deliverable input treatment plan; b. optimizing the deliverable input treatment plan to obtain an optimized treatment plan, using an objective function and at least one constraint, wherein i. the objective function is related to reducing the plan complexity in terms of minimizing the machine output (MU) and/or minimizing the time required to deliver the plan and/or maximizing the segment area, and/or minimizing jaggedness of the MLC shapes, ii. to ensure that the quality is maintained, the at least one constraint is based on the dose distribution of the input plan, related to maintaining an acceptable dose distribution.

Abstract: A method for generating data representing the volume of part of a body, the method comprising generating a point distribution model “PDM” based on an input dataset comprising data representing at least one surface of part of a body, the PDM defining a surface model dataset based on an average dataset and one or more weight-eigenvector pairs, generating a first surface model dataset based on the PDM by modifying at least one weight of the one or more weight-eigenvector pairs, wherein the first surface model dataset is different from the average dataset, and generating an output volume dataset based on the first surface model dataset and a first reference dataset, the first reference dataset comprising data representing the volume of a corresponding part of a body, the output volume dataset comprising data representing a deformed volume of the corresponding part of the body.

Abstract: A method of optimizing the use of resources in treatment planning involving more than one radiation set delivered to one or more patients, the radiation sets requiring different resources, respectively, wherein the optimization is performed using an optimization problem comprising an optimization function related to the first and second sets of resources. The method may be used for optimizing one plan for one patient, or a number of plans for different patients, in such a way that the available resources are used in the best possible way.

Abstract: A method of generating a radiotherapy plan for ion therapy, wherein the beam (6) is shaped by means of passive devices is arranged to allow variation in settings of at least one of the passive devices and/or the MU during the delivery of the beam and to control the movement of the patient and/or the beam in such a way as to create an arc. The arc is preferably a continuous arc or includes at least one continuous sub-arc. The method may include forward planning or optimization. In the latter case, the optimization uses an optimization problem set up to allow variation in settings of at least one of the range modulating device (9), the aperture element (11) and the MU during the delivery of the arc. Computer programs control the planning and the delivery.

Abstract: A method of evaluating a radiation therapy (RT) treatment plan for a treatment volume, divided into sub-volumes and having a target volume and one or more organs at risk, OAR. It includes obtaining a RT treatment plan; calculating the linear energy transfer, LET, in each sub-volume; dividing the dose distribution into doses of a first category and a second category in each sub-volume, wherein the first category comprises doses with energy depositions with an LET below a first LET threshold and the second category comprises doses with energy depositions with an LET above a second LET threshold; determining amounts of doses of the first and of the second category in each sub-volume; and performing an analysis of the quality of the RT treatment plan by metrics based on the obtained distribution of doses of the first and of the second category in the target volume and in the OAR.

Abstract: A method of radiotherapy treatment planning comprises optimizing a treatment plan based on at least one proposed dose map according to a set of clinical goals The resulting dose distribution is compared to the at least one clinical goal, and if the optimized dose distribution does not fulfil the at least one clinical goal, continuing with step d the dose map is adjusted before a new treatment plan is optimized. When the optimized dose distribution fulfils the clinical goals, the treatment plan is accepted.

Abstract: A method of performing dose calculations for ion radiotherapy compensating for tissue in which the density within a voxel may be inhomogeneous by approximating a portion of the voxel as an air cavity. For each dose voxel, the voxel is inscribed in a three-dimensional grid comprising a number of cells and the propagation of ions through the voxel is calculated based on the cell pattern in the at least one cell overlapping the voxel. Preferably, the voxel is inscribed in the three-dimensional grid in such a way that it overlaps at least one cell fully. Each cell comprises a first portion representing a first density corresponding to a density of a tissue and a second portion representing a second density corresponding to the density of air, the first and second portions forming a cell pattern.

Abstract: A method of obtaining an interpolated treatment plan is based on interpolating between associated dose distributions through optimization with respect to an optimization problem comprising optimization functions based on deviations from clinical goals. The method may suitably be used to improve navigated plans resulting from multi-criteria optimization.

Abstract: A method for automatic selection of a treatment plan for a patient is provided, where the automatic selection is at least partly based on the plan quality and required resources for each treatment plan in relation to the availability of resources.

Abstract: It is provided a method for obtaining an energy spectrum of a focused ion beam when a Bragg peak chamber is used to measure an integrated depth dose, IDD. The method comprises the steps of: simulating doses of a set of nominally mono energetic focused ion beams; determining a lateral extension of a Bragg peak chamber to evaluate; calculating a set of theoretic component IDD curves, CIDDs, by laterally integrating the dose of the simulated set of the nominally mono energetic focused ion beams, over the lateral extension of the Bragg peak chamber; storing calculated CIDDs; obtaining a measured IDD of a focused ion beam with a nominal energy using the Bragg peak chamber; and performing a fit of a linear combination of CIDDs to the measured IDD, to determine an energy spectrum for the focused ion beam with the nominal beam energy.

Abstract: Automatic radiation therapy treatment planning for generating a plan to be delivered from at least one beam angle, using a collimator having a variable collimator angle. Delivery times are determined for a number of possible collimator angles, and the optimization problem is defined to take the delivery times into account when selecting the collimator angles to be used when delivering the radiation.

Abstract: Accumulated path length for ions that reach a particular area of a patient is used in dose planning as an indicator of plan robustness. Also, the magnitude of the variations of the accumulated path lengths is determined for a number of beam directions, allowing beam directions to be selected for maximum robustness in treatment planning.

Abstract: A method of radiotherapy treatment planning involves dynamic target tracking and beam redirection. A set of 3D images of a patient reflecting a movement of the patient is obtained, and each image is deformably registered with one reference image. The accumulated dose is calculated as the sum of the dose distribution over all phases in dependence of the patient movement and the model of the delivery machine, the dose distribution for each phase being deformed by means of the deformation map for the respective phase, to match the reference image.