Computational algorithm of high-intensity focused ultrasound beams in cancer tissue model for hyperthermia therapy

Abstract

We calculate the acoustic field of a high-intensity focused ultrasound field in a 2D-model of human breast carcinoma and induce temperature elevation for the generation of necrosis. The computational operation is based on the Pennes bioheat concept. This method provides precise heat transfer values based upon thermal conduction in soft tissue and thermal convection in the domain of the blood. An ultrasound beam at 1 MHz was laterally focused on a tumor of 15.0 mm x 28.5 mm at different focal depths without elevational focalization. The length of each focus point of the ultrasound beam was 6.8 - 45.4 mm on the vertical axis, whereas the full width at half maximum was 1.1-2.5 mm on the horizontal axis. Simulated results showed that a discrepancy of the acoustic pressure around the focus area rises with focal depth. Like the pressure profile, when the focal depth is close to the ultrasound source, the thermal homogeneity around the focus area is attained, whereas thermal uniformity around the focus area becomes worse with increasing focal depth. Using the data visualization arrangement, a temperature profile corresponding to the obtained pressure profile is converted to attain a 2D image of a model of human breast carcinoma to show that tumor ablation was achieved and the healthy surrounding tissues were safe.