An inverse treatment planning model for intensity modulated radiation therapy with dynamic MLC

Abstract

The goal of radiation therapy treatment planning is to irradiate a tumor with ionizing radiation penetrating from several different directions and to destroy the tumor without causing damages to a healthy tissue. The intensity of the incoming radiation flux can be successfully modulated applying the multileaf collimator (MLC). In delivery, one can apply either the multiple static or dynamic collimation techniques. In the first method, the radiation is interrupted during the leaf movements whereas, in the second method, the radiation is continuously on. The trajectories of MLC leaves must be set as a function of time such that the desired dose distribution is achieved in patients as well as is possible. The problem is typically large dimensional and computationally a complex optimization problem. Previously, we have contributed a model to the multiple static method. This paper continues the work and we express a solution of the problem for dynamic collimation.