Optimizing pulse duration and interphase delay in high-frequency irreversible electroporation for glioma ablation: a...

Area of Science:

• Biomedical Engineering
• Neurosurgery
• Oncology

Background:

• Selection of high frequency irreversible electroporation (H-FIRE) pulse parameters for glioma ablation remains ambiguous in prior research.
• Understanding the dynamic conductivity of tumor and normal tissues based on H-FIRE pulse frequency is crucial for effective ablation.
• Optimizing H-FIRE parameters is essential to balance tumor destruction with minimizing damage to critical surrounding neural tissues.

Purpose of the Study:

• To develop a pulse waveform-dependent glioma ablation model for H-FIRE.
• To investigate the effects of pulse duration and interphase delay on glioma ablation, nerve excitation, and normal tissue damage.
• To identify optimal H-FIRE pulse parameters for effective glioma treatment while preserving neural function.

Main Methods:

• Developed a novel pulse waveform-dependent glioma ablation model incorporating dynamic tissue conductivity.
• Evaluated four typical H-FIRE pulse waveforms (5-1-5-1 μs, 5-5-5-5 μs, 10-1-10-1 μs, 10-5-10-5 μs).
• Determined optimal voltages for complete tumor ablation and assessed nerve excitation and white matter ablation volumes at these voltages.
• Performed sensitivity analysis to identify critical parameters influencing white matter ablation.

Main Results:

• Optimal ablation voltage decreased with increasing pulse duration and interphase delay (e.g., 2650 V for 5-1-5-1 μs vs. 1950 V for 10-1-10-1 μs).
• The 5-1-5-1 μs pulse demonstrated minimal neural excitability and white matter ablation volume, despite higher tissue temperature.
• Pulse duration significantly impacted white matter ablation and neural excitation more than interphase delays.
• Lethal electric field threshold (LEFT) of white matter was identified as the most critical parameter for white matter ablation outcomes.

Conclusions:

• Pulse parameters in H-FIRE significantly influence glioma ablation efficacy and safety, particularly pulse duration.
• The 5-1-5-1 μs pulse parameter set offers a promising approach for glioma ablation with reduced risk to surrounding neural tissues.
• This study provides a deeper understanding of the internal mechanisms governing H-FIRE parameter effects on glioma treatment.