Algorithm-controlled RF power output for enhanced margin precision in liver cancer radiofrequency ablation

Area of Science:

• Medical Engineering
• Oncology
• Biophysics

Background:

• Percutaneous radiofrequency ablation (RFA) is a standard liver cancer treatment.
• Incomplete ablation during RFA leads to higher local tumor recurrence rates.
• Current RFA methods struggle with precise control of ablation margins, risking incomplete tumor removal or excessive thermal damage.

Purpose of the Study:

• To develop and evaluate an algorithm-controlled ablation mode for precise control of tumor treatment margins in liver cancer.
• To utilize temperature and impedance as feedback parameters for adaptive adjustment of radiofrequency power output.
• To enhance both the effectiveness of tumor ablation and patient safety during RFA procedures.

Main Methods:

• Finite element analyses were performed to simulate temperature changes and ablation areas in biological tissue.
• Ex-vivo bovine liver experiments were conducted to compare traditional constant power ablation with the new algorithm-controlled mode.
• Real-time monitoring of temperature and impedance was employed in experiments to validate the algorithm's feasibility.

Main Results:

• The algorithm-controlled ablation mode effectively managed tissue impedance rise, preventing charring and carbonization.
• For 10mm and 20mm ablation diameters, boundary temperatures were precisely maintained between 50-60°C.
• This precision ensured effective ablation margin damage while minimizing harm to surrounding normal tissue.

Conclusions:

• An adaptive radiofrequency ablation algorithm using temperature and impedance feedback was developed for liver cancer treatment.
• Preliminary findings suggest this algorithm offers superior precision in controlling the ablation zone for small tumors (10-20mm diameter).
• The developed algorithm shows potential for improving the efficiency and safety of RFA compared to traditional constant power methods.