Temperature-Controlled Hyperthermia with Non-Invasive Temperature Monitoring through Speed of Sound Imaging

Abstract

Hyperthermia therapy (HT) is used to treat diseases through heating of high temperature usually in conjunction with some other medical therapeutics such as chemotherapy and radiotherapy. In this study, we propose a promising temperature-controlled hyperthermia method that uses high-intensity focused ultrasound (HIFU) for clinical tumor treatment combined with diagnostic ultrasound image guidance and non-invasive temperature monitoring through speed of sound (SOS) imaging. HIFU heating is realized by a ring ultrasound transducer array with 256 elements. In this study, tumors in the human thigh were set as heating targets. The inner structure information of thigh tissue is obtained by B-mode ultrasound imaging. Since the relationship between temperature and SOS in different human tissue is available, the temperature detection is converted to the SOS detection obtained by the full-wave inversion (FWI) method. Simulation results show that our model can achieve expected hyperthermia of constant temperature on tumor target with 0.2 °C maximum temperature fluctuation for 5 h. Through simulation, our proposed thermal therapy model achieves accurate temperature control of ±0.2 °C in human thigh tumors, which verifies the feasibility of the proposed temperature-controlled hyperthermia model. Furthermore, the temperature measurement can share the same ring ultrasound transducer array for HIFU heating and B-mode ultrasound imaging, which provides a guiding significance for clinical application.