Comparative experiments on phantom and ex vivo liver tissue in microwave ablation

Area of Science:

• Biomedical Engineering
• Thermal Ablation Technologies
• Medical Device Research

Background:

• Microwave ablation (MWA) is a minimally invasive therapeutic procedure.
• Accurate thermal field monitoring is crucial for effective MWA.
• Phantom models offer a potential alternative to ex vivo tissues for MWA research.

Purpose of the Study:

• To investigate and compare the thermal field distribution during microwave ablation in phantom and ex vivo liver tissue.
• To evaluate the suitability of using phantom models in place of actual liver tissue for future MWA studies.

Main Methods:

• Experiments were conducted on two groups: phantom and ex vivo porcine liver tissue.
• Microwave ablation was performed at 2450 MHz, 60 W for up to 240 seconds.
• Temperature data was recorded using 25 copper-constantan thermocouples (TCs) at specified positions.

Main Results:

• Non-symmetric temperature distribution was observed in the cooling water gap for both groups.
• Effective ablation areas were larger in regions without cooling water.
• Temperature curves showed good consistency near the microwave antenna but diverged further away.
• The cooling water effect was more pronounced in the phantom compared to liver tissue.
• Observed ablation shapes differed between the phantom and liver tissue.

Conclusions:

• Heating patterns in liver tissue and phantom models during MWA are comparable.
• Significant differences in temperature fields between phantom and liver tissue exist and cannot be overlooked.
• Researchers must carefully consider these discrepancies when using phantom models to simulate temperature fields for actual tissue ablation.