Study On Beam Weights Optimization With SCG Algorithm In Intensity-Modulated Radiotherapy

Radiotherapy, one of the three main treatments for tumor, is treat with about 60%-70% patients suffering from cancer and cures 40% of them. It is a historic advancement that the classical three-dimensional (3D) conformal radiotherapy (3DCRT) evolved into the intensity-modulated radiotherapy (IMRT). However, the advantages of IMRT have not been fully utilized yet, due to the complicated clinical conditions. There are still many problems in the IMRT planning, which is one of the basics of IMRT application, should be solved.With the development of IMRT and inverse planning , the automatic determination of suitable beam parameters in external beam radiotherapy has gained wide interests. In the conventional radiotherapy, the beam parameters are usually obtained by trial and error. The planning outcomes usually depend on the personal experience of planners. But there are large-scale parameters to be determined in the inverse planning of IMRT. It can hardly be carried out by trial and error. During last ten years, many methods have been proposed to optimize treatment plans such as linear programming, quadratic programming, gradient algorithms, constrained simulated annealing and genetic algorithms.