Determination of Optimal Beam Positions For Conformal Radiotherapy

The intensity modulated radiotherapy (IMRT) is a technique currently under development for the treatment of carcinogenic tumours, whose main objective is to concentrate the radiation dose in the tumour limiting the dose received by adjacent healthy tissue. The treatment by means of IMRT uses a discreet set of spatially distributed beams of radiation. Habitually, the radiation beams are placed separated with a fixed distance in the space around the patient, although sometimes the radiotherapist sets their position based on his own experience. In this article a new method is offered to determine the optimal position of the radiation beams, in such a way that the geometry of the patient is considered and the required dose in the different organs. The selection of positions is based on the study of a figure of merit (FoM), that allows the dose to be evaluated that the patient will receive. The proposed method has been applied on a real case of cancer, where the results obtained demonstrate a greater effectiveness in the treatments when considering the positioning of the beams according to the proposed method