Tumor Margin Estimation through Simulated Impedivity Mappings Using a Multielectrode Sensor Array

Area of Science:

• Biomedical Engineering
• Medical Imaging
• Electrical Impedance Tomography

Background:

• Accurate tumor margin identification is crucial for effective cancer surgery and preventing recurrence.
• Electrical properties of tissue change with pathological alterations, making impedance measurements a potential tool for tumor detection.
• Current multielectrode impedance sensors provide planar tissue mapping but suffer from inaccuracies due to uncorrected electrode configurations.

Purpose of the Study:

• To introduce a novel method for impedivity mapping by incorporating a geometry factor to correct for electrode configurations.
• To compare the accuracy of the new impedivity mapping technique against traditional impedance mapping for tumor margin estimation.

Main Methods:

• Developed an analytical formula for the geometry factor in four-electrode measurements.
• Simulated impedance measurements using a quadratic multielectrode sensor array.
• Generated impedivity maps by scaling impedance values with the calculated geometry factor.
• Estimated tumor margins using Otsu's method on both impedance and impedivity maps.

Main Results:

• The novel impedivity map significantly outperformed the standard impedance map in all simulated tumor scenarios.
• Impedivity mapping achieved 90.3% accuracy for surface tumors, compared to 85.7% for impedance mapping.
• For deeper-seated tumors, impedivity mapping accuracy ranged from 84% to 91%, while impedance mapping accuracy dropped as low as 36%.

Conclusions:

• The proposed impedivity mapping method provides a more accurate estimation of tumor margins than conventional impedance mapping.
• This technique holds significant promise for improving surgical outcomes in cancer treatment.
• Experimental validation is the necessary next step to confirm these simulation findings.