Position optimization of brachytherapy sources at 2D and 3D using genetic algorithm

Optimization in radiotherapy is one of an important and attractive topic in Medical Physics. In this study, we have written a computer code base on genetic algorithm using MATLAB software, to optimize the best places of brachytherapy sources with optimal value of a parameter which is determined by weight. The weight parameter is related to the activity of each seed implant brachytherapy sources, such as iodine -125, or the irradiation time in each place after loading brachytherapy source like Iridium-192. We have run the code for some arbitrary tumor’s shapes in two and three dimensions spaces and the optimized places for seeds of Ioine-125 brachytherapy source and their activities are founded. For each tumor, the optimization is done so that the points on the boundary edge of two-dimensional or three-dimensional object, points on the surface and all points within a given dose greater or equal to the dose on the surface or in the border areas have. The Isodose curves show the result of dose optimization is done at the desirable level.