Monitoring of temperature and denaturation for hyperthermia therapy via a noninvasive, locally and temporarily resolved measurement of sound velocities

• Applicant: Professorin Dr. Elfgard Kühnicke
• Subject Area: Measurement Systems ; Acoustics
• Term: since 2015
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 260366138

In cancer therapy, local hyperthermia and ablative thermal procedures for the destruction of tumor tissue represent an alternative or supplement to radiotherapy and chemotherapy. To avoid complications and for an effective application, it is necessary to monitor temperature distribution and potential tissue denaturation. This is particularly important in the area of vulnerable structures such as nerves or blood vessels. For ultrasound-based monitoring, measurements of longitudinal wave velocity and transverse wave velocity are well suited, the former being sensitive to changes in temperature and the latter to changes in tissue structure. These ultrasound-based measurements provide an alternative to other costly temperature monitoring, such as MRI, and therefore show great potential for effective temperature monitoring during therapy with radiofrequency ablation and HIFU. The aim of the project is to continue the successful work from the previous project. A procedure for spatially resolved measurement of longitudinal wave velocity has been developed. By evaluating scattering echoes of tissue structures, the procedure works without any additional transducers or reflectors at known positions. Compared to other methods presented in the literature since 2018, the method is the only one that meets the performance requirements for medical applications in terms of spatial and temporal resolution. This innovative method is thus predestined for the generation of sound-velocity and temperature maps, for the improvement of beamforming and for the correction of conventional B-scans. Another benefit of the method is the improvement of the performance of shear wave elastography. For SWEI, the accuracy of transverse wave velocity determination is significantly increased and source localization is enabled. In the project, the performance of the method is to be demonstrated for a variety of medical applications, thus paving the way for the clinical realm. For this purpose, the following tasks will be addressed: 1, the accuracy of the method will be significantly increased by sound-field-based optimization of the transducers; 2, adapting the method for linear medical arrays (from the annular arrays used so far); 3, implementation of the method on Verasonic’s research platform VANTAGE 64 LE; und 4, the imaging enabled by the implementation. After systematic examination of complex tissue phantoms, subsequent measurements on ex-vivo samples are planned in cooperation with our medical partner specialized in HIFU treatment at the SRH Wald-Klinikum Gera.

• DFG Programme: Research Grants
• Major Instrumentation: Ultraschallforschungsplattform
• Instrumentation Group: 3900 Ultraschall-Diagnostikgeräte
• Co-Investigator: Professor Dr.-Ing. Christian Kupsch