Modeling On Automatic Selecting Beam Arcs In X-Knife Radiation Therapy Planning System

The radiotherapy planning plays an important role in X-Knife system, and it's developing towards automatic planning and optimized planning based on the advancing technology of computer science and medical imaging technology. The automatic selecting beam arcs is one of the most important tasks in X-Knife automatic therapy planning. The most important part of our research work, modeling and developing practical method for automatic selecting beam arcs, is presented in this paper. First of all, the history of X-Knife is reviewed, and the theory of X- Knife is introduced briefly. The principle of 3-D radiotherapy planning and optimization is followed. All of these are important for the research of X- Knife automatic radiotherapy planning. Then the main problems of X-Knife automatic radiotherapy planning are analyzed in detail, and the main ideas of modeling are discussed. With the guidance of the theory of dose attraction and dose repulsion introduced by Professor Shuxiang Li , we established the model of relative dose distribution in beam rotation plane by deeply analyzing the character of dose distribution. We also introduced the calculation formulas of dose attraction and dose repulsion, and improved the calculation of CPV (Coronary Plane View) and BPV (Beam Plane View). Further more we carried out the queuing and automatically selecting beam arcs using CPV and BPV. The results of experiment have approved the model's importance to the research of X-Knife automatic radiotherapy planning.