Beam Orientation Optimization Methods in Intensity Modulated Radiation Therapy Treatment Planning ........... dionne m. aleman, h. edwin romeijn, and james f. dempsey
Abstract The intensity modulated radiation therapy (IMRT) treatment planning problem consists of several subproblems, which are typically solved sequentially. This chapter addresses the beam orientation optimization (BOO) problem, and to some extent, the ﬂuence map optimization (FMO) problem. The BOO problem is the problem of selecting from which beam orientations to deliver radiation to the patient. The goal of beam orientation optimization is to select the best beams from which to deliver the radiation so that the treatment plan can deliver the prescribed amount of radiation dose to the target cells while simultaneously delivering a small enough amount of radiation to the surrounding tissue so that nearby organs will continue to function properly after radiation therapy. The solution to the FMO problem, the problem of determining the amount of radiation intensity (ﬂuence) of each beamlet in each beam, is generally accepted as the measure of the quality of a beam solution. However, due to the cost of evaluating the FMO problem, a number of alternative approaches have been taken to model and to solve the BOO problem. This chapter summarizes many of the BOO methods presented in the literature.