I have been involved in non-invasive electrical brain stimulation research work for some time now....been working with a science driven medical device firm involved in non-invasive brain research for about 15 yrs. Needless to say, I have serious doubts on how effective their device and approach is in terms of spatial specificity of targeting the tumor cells as well as avoiding stimulation (and thereby damage) of non-target (healthy) cells. I think they use alternating currents upon a quick review on their website. And if that's the case, I am a big skeptic! Non-invasive electrical stimulation is not known for it's spatial specificity given the high impedance of the skull and inhomogeneity of various tissues that it needs to travel through.