[Ultrasound control of thermal tissue therapy]

Area of Science:

• Medical Physics
• Biomedical Engineering
• Oncology

Background:

• Minimal invasive interstitial thermal treatment is crucial for tumors and metastases, often complementing chemo- or radiotherapy.
• Current non-invasive methods for monitoring these thermal therapies lack routine applicability and economic feasibility, with nuclear magnetic resonance tomography being an exception.

Purpose of the Study:

• To evaluate the potential of non-invasive control of thermal therapies using radio frequency ultrasound signals.
• To assess temporal and spectral analysis of ultrasound for monitoring tissue temperature during thermal ablation.

Main Methods:

• Investigated two ultrasonic procedures for non-invasive therapy control.
• Procedure 1: Analyzed local modifications in ultrasound time-of-flight to determine tissue temperature distribution.
• Procedure 2: Examined physical attenuation characteristics of biological tissue and their temperature dependence.

Main Results:

• Demonstrated the possibilities and limitations of both proposed ultrasonic procedures through in vitro experiments.
• Presented preliminary results from a prototype control system for thermal therapy monitoring.
• Showcased the feasibility of using ultrasound signal analysis for temperature assessment.

Conclusions:

• Non-invasive control of thermal therapies using ultrasound signal analysis is a promising alternative.
• The evaluated ultrasonic methods offer potential for routine, economical application in thermal treatment monitoring.
• Further development of the prototype system is warranted for clinical translation.