Treating the electric with the electric. The boundary between the brain and the environment seems to be permeable.

“A device that specifically targets rapidly growing cancer cells with intermediate frequency electrical fields — called Tumor-Treating Fields (TTFields) — doubled the survival rates of patients with brain cancer, according to a Proceedings of the National Academy of Sciences (PNAS) journal article.”

http://pressesc.com/01180456249_brain_cancer_electric_field