  Tumor Treating Fields (TTFields) is a non-invasive anticancer modality that
utilizes alternating electric fields to disrupt cancer cell division and
growth. While generally well-tolerated with minimal side effects, traditional
TTFields therapy for lung tumors faces challenges due to the influence of
respiratory motion. We design a novel closed-loop TTFields strategy for lung
tumors by incorporating electrical impedance tomography (EIT) for real-time
respiratory phase monitoring and dynamic parameter adjustments. Furthermore, we
conduct theoretical analysis to evaluate the performance of the proposed method
using the lung motion model. Compared to conventional TTFields settings, we
observed that variations in the electrical conductivity of lung during
different respiratory phases led to a decrease in the average electric field
intensity within lung tumors, transitioning from end-expiratory (1.08 V/cm) to
end-inspiratory (0.87 V/cm) phases. Utilizing our proposed closed-Loop TTFields
approach at the same dose setting (2400 mA, consistent with the traditional
TTFields setting), we can achieve a higher and consistent average electric
field strength at the tumor site (1.30 V/cm) across different respiratory
stages. Our proposed closed-loop TTFields method has the potential to improved
lung tumor therapy by mitigating the impact of respiratory motion.
