Author: Sung Hwan Ahn, Yongha Gi, Jinju Heo, Jinyoung Hong, Yunhui Jo, Yousun KO, Hyeongjin Lim, Sang Yoon PARK, Myonggeun Yoon 👨🔬
Affiliation: Institute of Global Health Technology (IGHT), Korea University, Republic of Korea, Korea University, Samsung Medical Center 🌍
Purpose:
This study aims to evaluate the feasibility of real-time monitoring of conductivity changes induced by thermal variations during tumor treating fields (TTFields) therapy using Electrical Impedance Tomography (EIT). Various current injection and voltage measurement patterns were assessed for their effectiveness in achieving precise and efficient monitoring.
Methods:
A rectangular cuboid phantom model with 80 electrodes, arranged in 4 layers with 10 electrodes per layer, was developed. The EIT module estimated conductivity distributions using four patterns: adjacent-electrode injection and measurement (Pattern 1), multiple-electrode injection with voltage measurement at current electrodes (Pattern 2), multiple-electrode injection with non-current electrode measurements (Pattern 3), and multiple-electrode injection with voltage pair measurements (Pattern 4). Conductivity changes were computed using finite element methods (FEM), and the estimated distributions were evaluated with mean error and histogram analysis on the middle phantom plane.
Results:
The maximum errors for Patterns 1, 2, 3, and 4 were 6.29%, 5.29%, 5.28%, and 5.36%, respectively, with corresponding mean errors of 0.62%, 1.70%, 0.88%, and 1.19%. Pattern 4 achieved the highest accuracy with no observable error, while other patterns showed varying accuracy levels depending on configuration.
Conclusion:
EIT-based monitoring of conductivity changes in TTFields therapy is feasible and effective. The reduced measurement pattern (Pattern 4) offers accurate monitoring without additional EIT equipment, supporting its potential integration into clinical workflows.