Abstract: A computer-based method of optimizing a radiotherapy treatment plan for treating a patient involving radiation being delivered by a beam describing an arc is defined, the method including defining at least a first and a second part of the arc, the first part being a first sector of the arc and the second part being a second sector or a static beam, obtaining an optimization problem including at least a first optimization function for the first part, and a second optimization function for the second part and optimizing the radiotherapy treatment plan based on the optimization problem.

Abstract: A method of creating an ion-based radiotherapy treatment plan includes a spot-weight optimization procedure arranged to create the plan involving an arc as a combination of one or more sub-arcs and possibly a static beam wherein the one or more sub-arcs either overlap or have different directions. The method includes selecting the first and second sets of energy levels together.

Abstract: A radiotherapy treatment plan may be evaluated based on a combination of two or more metrics, by the steps of simulating the result of delivery of the plan, obtaining values from the simulation for at least a first and a second metric, performing a multivariate analysis of the values and determining a quality of the plan based on the result of the multivariate analysis. The metrics may include at least one of dose, LET, track ends, RBE, alpha/beta ratio and statistical uncertainty of the plan.

Abstract: A computer-based method of providing a set of selected spots for use in ion radiotherapy optimization is proposed, the method comprising the steps of defining a number of positions in the volume, each position corresponding to a possible Bragg peak location, the positions being defined to provide coverage of the volume, for each position, for at least one beam direction, performing a ray trace to determine characteristics of a potential spot in the beam that will place its Bragg peak in the position and for each position, selecting zero, one or more of the potential spots, based on the characteristics, and including the one or more selected spots in the set of selected spots. The set of selected spots may be used in treatment planning. The invention also relates to computer program products and a computer system for performing the methods.

Abstract: A method for dynamically estimating a biological effect of a variable combination of non-photon radiation in accordance with a relative biological effectiveness, RBE, model including at least one biological effect multiplier ?(T, E) which depends on particle type T and/or particle energy E, the method comprising: obtaining one or more non-photon radiation contributions D(i)(T, E), 1 ? i ? N, at least one of said contributions including multiple particle types and/or multiple particle energies; storing per-contribution dose-weighted averages ??(i), 1 ? i ? N, of said at least one biological effect multiplier with respect to each of the one or more contributions; and in response to obtaining an assignment ? of the combination, the assignment being in terms of non-negative coefficients k1, k2, ...

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: 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 beam, and each energy level is assigned to one of the plurality of sub-beams. The step of assigning a ripple filter setting comprises optimizing based on different filter settings for different sub-beams for each beam direction.

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: 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: According to a first aspect, it is presented a method for determining a treatment plan comprising a distribution of spots for use with ion beam therapy for providing the spots in a target volume. The method comprises the steps of: selecting energy layers to be used in the treatment plan; determining a number of spot sizes to use; generating, for each energy layer, one copy of the energy layer for each spot size to use and populating each copy with spots of the spot size for that copy; optimizing spots of all copies of all energy layers, by repeatedly varying a weight of at least a subset of the spots and calculating an effect on a performance measurement, wherein the performance measurement is calculated by combining a plurality of evaluation criteria, comprising a first criterion related to total treatment time and a second criterion related to a desired dose distribution.

Abstract: An optimization method for ion based radiotherapy includes inverse planning based on optimization variables related to the particle energy, a range modulator or ridge filter, a block and/or a range compensator. This enables automatic optimization of complex cases.