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: An estimated or predicted dose for radiotherapy treatment may be generated based on a partial dose map including dose information only for one or more regions of interest within a treatment site, by use of a properly trained machine learning system such as a U-Net or a V-Net. Said partial dose map typically set to fulfil clinical goals. A method of training such a machine learning system is also disclosed.

Abstract: The present disclosure generally relates to the field of radiation treatment. More specifically, the present disclosure generally relates to methods and radiation treatment systems for facilitating a multimodal radiation therapy treatment plan, in particular a multimodal radiation therapy plan employing a combined photon beam and electron beam radiation treatment. According to one example embodiment described in the disclosure, a method may comprise obtaining information related to a set of candidate beam types for the combined photon beam and electron beam radiation treatment; comparing the set of candidate beam types against a selection criterion to establish a subset of beam types from the candidate beam types; and generating the combined photon beam and electron beam radiation treatment plan utilizing the thus established subset of beam types.

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.

Abstract: A computer-implemented method for generating a radiation therapy treatment plan for a volume of a patient, the method comprising: receiving an image of the volume; receiving at least one dose-distribution-derived function configured to provide a value as an output based on, as input, at least part of a dose distribution defined relative to the image; receiving a first probability distribution and at least a second, different, probability distribution, the first and at least second probability distributions; defining a multi-criteria optimization problem comprising at least a first objective function based on the at least one dose-distribution-derived function, the first probability distribution and a loss function; and a second objective function based on the at least one dose-distribution-derived function, the second probability distribution and the loss function; and performing a multi-criteria optimization process based on the at least two objective functions to generate at least two output treatment plans

Abstract: A compensating device for use in ion-based radiotherapy may comprise a disk with a number of protrusions may be placed in a radiation beam to affect the ions in the beam in different ways to create an irradiation field from a broad beam. This is particularly useful in FLASH therapy because of the limited time available or modulating the beam. A method of designing such a compensating device is proposed, comprising the steps of obtaining characteristics of an actual treatment plan comprising at least one beam, determining at least one parameter characteristic of the desired energy modulation of the actual plan by performing a dose calculation of the initial plan and, based on the at least one parameter, computing a shape for each of the plurality of elongated elements to modulate the dose of the delivery beam to mimic the dose of the initial plan per beam.

Abstract: A radiotherapy treatment planning method for achieving a FLASH radiotherapy treatment plan involves optimizing the plan using an optimization problem that has been designed to maximize the part of the irradiation that will be delivered under FLASH conditions, in particular to an organ at risk, to minimize the damage to the organ at risk.

Abstract: A computer based method of obtaining a 3D image of a part of a patient's body is disclosed, based on a fraction image having a limited field-of-view and extending the field of view with information from an image of the patient's outline, obtained from a surface scan of the patient. Anatomical data from the planning image are preferably used to fill in the outline image, by means of a contour-guided deformable registration between the planning image and contour.

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: It is provided a method for determining arc costs. The method comprises the steps of: determining a plurality of beam orientations; evaluating a set of at least one cost function comprising an intermediate exposure cost function that is evaluated by performing the substeps of: projecting the at least one target volumes on a beam plane; determining an alignment angle based on a collimator angle value; finding any intermediate area in the beam plane along the alignment angle between areas of the at least one target volume projection; determining a value of the intermediate exposure cost function. The method further comprises the steps of: finding a plurality of arcs, wherein each arc comprises a sequence of a plurality of beam orientations; and calculating, for each arc in the plurality of arcs, at least one arc cost based on the cost function values of the beam orientations of the arc.

Abstract: A method of optimizing a radiation treatment plan of ion treatment, in which the optimization procedure is interrupted, some but not all low-weight spots are discarded and the optimization procedure is resumed with a reduced set of spots. The weight of one or more remaining spots may be increased before resuming the optimization procedure, for example by adding the spot weight of one or more of the discarded spots to one or more of the remaining spots.

Abstract: It is provided a method for determining a distribution of spots for use with ion beam therapy for providing the spots in a target volume, wherein each spot represents a collection of ions of a specific energy level and of a specific size at a specific lateral location. The method is performed in a treatment planning system and comprises the steps of: dividing the target volume in a plurality of target sections based on a user configuration comprising at least one spot size strategy defining a maximum spot size at the location of a Bragg peak; assigning a spot size strategy to each one of the target sections based on the location of the respective target section; and determining, within each target section, spots in accordance with its spot size strategy.

Abstract: It is provided a method for checking quality of a treatment plan, wherein a treatment plan specifies a distribution of radiation to thereby provide radiation to a planning target volume. The method is performed by a quality assurance device and comprises the steps of: obtaining a treatment plan and a corresponding first dose, the treatment plan having been calculated in a treatment planning system, the first dose being a predicted dose to be deposited in the patient using the treatment plan; initiating a calculation of a secondary dose, being a dose deposited by the treatment plan, using a secondary dose calculation algorithm; repeatedly calculating a confidence interval of a comparative statistical measurement by comparing the first dose and the secondary dose over a defined geometric volume; and interrupting the calculation of the secondary dose when the confidence interval is better than at least one predefined criterion.

Abstract: A system for determining a treatment plan in active ion beam treatment, to minimize unwanted dose, while maintaining or improving target dose coverage, whereby a beam is split into at least two sub-beams and where each sub-beam has a range shifter of different settings.

Abstract: It is provided a method for providing a treatment plan for radiotherapy when the delivery is interrupted, the method being performed by a treatment planning system. The method comprises the steps of: detecting that delivery of a first treatment plan has been interrupted; obtaining an indication of delivery of a partial dose, representing the part of the first treatment plan that was delivered prior to the interruption; generating a second treatment plan, wherein the partial dose delivery forms an input to the second treatment plan generation as a background dose; and optimizing the second treatment plan while considering a plurality of scenarios.

Abstract: It is provided a method for optimizing a treatment plan for use in radiation therapy. The method is performed in a treatment planning system and comprises the steps of: obtaining a first quality function of the treatment plan, the first quality function yielding an output value based on an input treatment plan; obtaining a first pair of input values and a slope indicator, the input values associating a value of the first quality function to a value of a score; constructing a score function that maps values of the first quality function to values of the score by fitting a curve to the first pair of input values and the slope indicator; and optimizing the treatment plan with respect to the score function, by varying the treatment plan such that the value of the score function is either improved or constrained to a feasible range of score values.

Abstract: It is provided a method for generating a plurality of treatment plans for radiation therapy, each treatment plan specifying weights for a plurality of geometrically defined fluence elements. Each weight defines an amount of radiation fluence, to thereby provide radiation dose to a target volume. The method is performed in a treatment planning system and comprises the steps of: generating a first set of treatment plans; determining a subset of the fluence elements, based on the first set of treatment plans; and generating a second set of at least two treatment plans, wherein the treatment plans only contain weights for the subset of fluence elements.

Abstract: A method for generating a robust radiotherapy treatment plan for a treatment volume of a subject, the treatment volume being defined using a plurality of voxels, the method comprising the steps of defining (S100) an optimization problem using at least one optimization function for a biological endpoint related to the radiotherapy treatment; defining (S102) a set of scenarios comprising at least a first scenario and a second scenario, wherein at least two of the scenarios in the set of scenarios represent different biological models to quantify the same biological endpoint; calculating (S104) an optimization function value for each scenario in the set of scenarios; generating (S106) a radiotherapy treatment plan by robustly optimizing the optimization function value evaluated over the set of scenarios

Abstract: It is provided a method for determining ripple filter settings for an ion therapy beam being capable of providing ions of different energy levels to a target volume. The method is performed in a treatment planning system and comprises the steps of: determining at least one beam direction to use to cover a target volume; and assigning a ripple filter setting to each one of a plurality of sub-beams of each one of the at least one beam direction such that each sub-beam is assigned a different ripple filter setting, wherein each ripple filter setting results in a different effect on a Bragg-peak width in a direction along the ion therapy beam, and each energy level is assigned to one of the plurality of sub-beams. The step of assigning a ripple filter setting comprises optimising based on different filter settings for different sub-beams for each beam direction.

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.