Computed modeling of alternating electric fields therapy for recurrent glioblastoma

Tumor treating fields (TTFields) are alternating electric fields frequency tuned to 200 kHz for the treatment of recurrent glioblastoma. We report a patient treated with TTFields and determined the distribution of TTFields intracranially by computerized simulation using co-registered postgadolinium T1-weighted, T2, and MP RAGE images together with pre-specified conductivity and relative permittivity values for various cerebral structures. The distribution of the electric fields within the brain is inhomogeneous. Higher field intensities were aggregated near the ventricles, particularly at the frontal and occipital horns. The recurred tumor was found distant from the primary glioblastoma and it was located at a site of relatively lower electric field intensity. Future improvement in TTFields treatment may need to take into account the inhomogeneity of the electric field distribution within the brain.