Computer Simulation of Tumor Treating Fields

Tumor treating electric fields or TTFields are emerging as a new treatment modality for cancer, and its first FDA-approved use is in glioblastoma patients. TTFields are alternating electric fields at 200 kHz continuously delivered by the Optune device to the scalp of patients. Preclinical experiments have shown that they interfere with dividing cancer cells as they undergo metaphase-to-anaphase transition in mitosis and, specifically, they disrupt α/β tubulin and septin proteins that have high dipole moments. However, the visualization of TTFields in the brain and therefore treatment verification require complex computational simulation and modeling of electromagnetic wave propagation, which entails added difficulties due to the different conductivity and relative permittivity values of various intracranial tissues and cavities. The procedure requires segmenting tissue structures as seen on the MRI, generating a 3-dimensional mesh for each segmented volume, and importing the composite mesh into a finite element solver of Maxwell’s equations. In turn, the finite element analysis process involves the identification and application of material parameters to different segmented tissue types, specification of appropriate boundary and initial conditions, as well as identification of the best fit solution for the electric field distribution, all of which are dependent on the transducer array layout as generated by proprietary NovoTAL computer software. Ultimately, the precise visualization of the TTFields in the glioblastoma and adjacent brain tissues may enable neuro-oncologists and physicist to improve TTField delivery in the brain.