Study of the HIFU Therapy Methodology in Treating the Liver Cancer

Liver is one of the main targets of metastases from different cancers. There are a lot of methods of treating liver cancer, such as high-intensity focused ultrasound ablation (HIFU therapy). One of the problems affecting the treatment efficiency is ability to adjust the focal area parameters. This paper studies possibilities of controlling focal area parameters in the liver tissue by changing the voltage phase that excites three segments of the ultrasonic transducer. Mathematical model of interaction between the ultrasonic transducer and the liver tissue is proposed. Computational experiment was carried out to calculate alteration in geometric dimensions and position of the focal area center by adjusting the voltage phase that excited the ultrasonic transducer segments. It was established that when the extreme segment phase was changing by ±45°, maximum temperature in the focal area was increasing up to 90.5°C (from 87.0°C), and out of the focal area it was decreasing down to 42.1°C (from 42.6°C). The focal area center was shifting down by 4.0 mm.