A novel strategy to increase heating efficiency in a split-focus ultrasound phased array

Area of Science:

• Medical Physics
• Biomedical Engineering
• Acoustic Therapy

Background:

• Sector-based phased arrays with focus splitting enhance necrosed tumor volume and reduce treatment time.
• Split-focus sonication faces limitations due to lower energy density and focal-beam distortion.

Purpose of the Study:

• To propose and validate a new ultrasound heating strategy combining consecutive strongly focused and split-focus sonications.
• To improve heating efficiency and overcome limitations of current split-focus sonication techniques for tumor treatment.

Main Methods:

• Theoretical predictions, including linear and thermal-dose-dependent attenuation changes, were used for analysis.
• Ex vivo tissue experiments were conducted to confirm the effectiveness of the proposed strategy.

Main Results:

• The proposed strategy produced larger thermal lesions compared to previous methods.
• It achieved faster thermal lesion induction and demonstrated higher robustness to blood perfusion and power variations.
• The technique showed superiority in generating deep-seated lesions through complex tissue interfaces.

Conclusions:

• The combined focused and split-focus sonication strategy optimizes thermal conduction and temperature buildup.
• This technique enhances the applicability of split-focus and multiple-focus sonication for clinical tumor treatment.
• It offers a solution to shorten total clinical treatment times effectively.