System and method for planning a radiation therapy treatment

Abstract

A system plans a radiation therapy treatment of a target volume based on inputs in the form of: a set of candidate beams (B), where each beam defines an arrangement of a therapeutic beam relative to the target volume; a treatment plan (x) for the radiation therapy treatment that uses a subset of the candidate beams (B); an objective function (F) describing a quality of the treatment plan (x); and a feasible region (X) describing requirements on the treatment plan (x) that must be fulfilled. The objective function (F) and/or the feasible region (X) also reflect a first complexity criterion (τ(x)≤{circumflex over (τ)}) limiting a first complexity measure (τ(x)) to be less than or equal to a maximum first complexity ({circumflex over (τ)}). An optimization step is executed repeatedly; whereby, in each iteration, an updated treatment plan (x') is calculated by optimizing the treatment plan (x) with respect to the objective function (F) and the feasible region (X). Here, if a termination criterion is fulfilled, a set of selected beams (B*) is calculated based on the updated treatment plan (x′). The set of selected beams (B*) is a subset of the set of candidate beams (B). Otherwise, the updated treatment plan (x′) is set to the treatment plan (x); an updated first complexity criterion (τ′(x)≤{circumflex over (τ)}′) is calculated; the updated first complexity criterion (τ′(x)≤{circumflex over (τ)}′) is set to the first complexity criterion (τ(x)≤{circumflex over (τ)}), and another iteration of the optimization step is executed.