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Updated: Dec 3, 2025
Thermal Ablation for the Treatment of Abdominal Tumors
Published on: March 7, 2011
Ex Vivo Performance of a Flexible Microwave Ablation Antenna
Objective:
In this study, we investigate the performance of a flexible microwave ablation antenna for generating localized ablation zones.
Methods:
We designed a helical dipole antenna to operate at 1.9 GHz in egg white and liver. Semi-rigid prototypes of the antenna were fabricated and used to perform ablation experiments in egg white and perfused liver. Pulsed and continuous-wave power deliveries at different power levels were used. Flexible prototypes of the antenna were fabricated and used to perform ex vivo ablation experiments in perfused liver.
Results:
Pulsing was effective in reducing the shaft heating of semi-rigid cables. The antenna was capable of producing substantial ablation zones in perfused liver. Typical diameters (perpendicular to the antenna axis) of generated ablation zones with semi-rigid antennas in egg white and perfused liver were 30 mm and 20 mm, respectively. The flexible antenna had a good impedance match while bent. Average diameter of generated ablation zones by the flexible antenna with 10-W continuous-wave experiments in perfused liver was 26 mm. No significant difference was observed between the performances of semi-rigid and flexible prototypes.
Conclusion:
The flexible helical dipole antenna is capable of maintaining its good impedance match while bent and can generate substantial ablation zones in presence of perfusion.
Significance:
The proposed flexible antenna is promising for minimally invasive treatment of tumors that are otherwise inaccessible by rigid antennas. One example is lung where a catheter-based deployment of the flexible antenna into the tumor via airways may substantially reduce risks associated with using rigid antennas.
