P3C-7 Investigation of Dual Curved Ultrasound Phased Arrays for Breast Tumor Thermal Therapy

The purpose of this study was to investigate the feasibility of using two curved ultrasound phased arrays with a rapid focus-scanning scheme for breast tumor thermal therapy. The driving frequency, radius of curvature, length and width of the phased arrays are 1 MHz, 15 cm, 16 cm and 1.5 cm, respectively. The two phased arrays were arranged face-to-face with a distance of 24 cm, and the planning target volume (PTV) was centered between two phased arrays. The foci of the phased arrays were located at the PTV and scan sequentially. After an appropriate sonication time, two phased arrays rotate 90 degree and continue to sonicate to achieve a uniform heating for the PTV without overheating normal tissues. Computer simulation and experiments with color-changeable phantom and fresh pork tissue had been used to evaluate the proposed heating system. Results indicated that the heating system was able to create a uniform heating in the PTV with a minimum acoustic power deposition in ribs due to acoustic beams emitted from phased arrays parallel to ribs. In addition, phased arrays were tilted with thetas_T (65deg) when the PTV closes to the chest wall to avoid the overheating in ribs, while the distance from the chest wall to the PTV center was 1 cm with thetas_T of 65deg for breast tumor thermal therapy.