This 2011 TED Talk might be of interested to the community: Tumor Treating Field
Learned about this from a business channel. Since 2011, there is a company called Novacure that has treatments approved by FDA for Recurrent Glioblasoma and Newly Diagnosed Glioblastoma (brain cancer) and has phase 1 or 2 trials for a variety of cancers, including Non Small Cell Lung Cancer. One can also easily wonder whether this will work for situations where cancers traveled to brain.
The company Novocure now has two treatments approved by FDA and are doing clinical trials on a variety of cancers., with non small cell lung cancer (mestease to the brain) completed phase 2. So hopefully, the modality is now more than just a proof of concept.