Microwave Hyperthermia for Breast Cancer Treatment Using Electromagnetic and Thermal Focusing Tested on Realistic Breast Models and Antenna Arrays

A technique for noninvasive microwave hyperthermia treatment for breast cancer is presented. In the proposed technique, electromagnetic (EM) focusing on patient-specific breast models is implemented to concentrate the power at the tumor position while keeping the power levels at other positions (healthy tissues) at minimum values. This step is realized by optimizing phase excitations of the utilized antenna elements. In the next step, a thermal analysis is used to determine the scaling factor of the antennas´ excitation amplitudes to realize the required temperature at the tumor position. A closed-loop procedure ensures that there are no hot spots in any of the healthy tissues. The technique is tested in a realistic environment which includes three-dimensional breast models and antenna arrays. The presented results on fatty and dense breast models using two types of directional antennas validate the proposed technique. The investigations across wide frequency bands indicate that the frequencies around 4.2 and 4.5 GHz are optimum values for the hyperthermia treatment of dense and fatty breasts, respectively.