| Two kinds of applicators for hyperthermia on chest wall recurrence are evaluate by simulation in this thesis. One applicator is waveguide including 10m by 10cm and 10cm by 15cm operating at 915MHz, and the other is a 433MHz spiral antenna with a radius of 4.572cm. The simulations perform E-field calculations with the finite difference time domain (FDTD) method. In these 3D FDTD simulations, the patient models are derived from CT images, where material properties are assigned to tumor, skin, fat, and muscle tissues. The thickness and temperature of the water bolus and the position of the applicator are adjusted in these simulations, and a parametric study is performed on the resulting 3D patient model. Results show that the 433MHz spiral antenna generates larger thermal dose when the tumor is near the skin surface. For each applicator, the simulation results suggest the corresponding optimal configuration for different tumor target locations on the chest wall. Future efforts will incorporate these results into a comprehensive treatment planning system that optimizes the robot arm trajectory and combines these results with 3D visualization of static and dynamic temperature distributions on the chest wall. |
