Mild-Hyperthermia Generation and Control with a Ring-based Ultrasound Tomography

Hyperthermia-enhanced chemo- and radiation therapies have been used in the treatment of various types of cancers such as breast, and soft-tissue sarcoma. Localized hyperthermia can increase the effectiveness of treatment and reduce the dosage requirements. Simultaneous temperature monitoring has generally required the use of additional modalities such as magnetic resonance imaging (MRI). Ultrasound (US) offers the potential for an all-in-one solution for heat induction and temperature monitoring through speed of sound (SOS) measurements. Such a system would ease the utility of hyperthermia-enhanced therapies and minimize the required hardware/costs, thereby presenting an attractive alternative. In this study, we present the results for 1) all-acoustic, in-silico, localized heating of a numerical breast phantom with embedded tumor, and 2) ex-vivo thermometry results, which look at monitoring the changes in water sound speed at 25, 35, and 45 °C in a heterogeneous lamb tissue phantom. The measurements from the thermometry experiment were then compared against the known values from the literature. The results from this study show successful all-acoustic induced localized heating and good agreement between the measured water sound speed values and their literature counterparts, which represent a significant step toward the development of a real-time US hyperthermia system.