Hello,
I'd like to share this interesting recent article on sodium selenite (SS) which is effective against glioblastoma: "Anticancer properties of sodium selenite in human glioblastoma cell cluster spheroids" .
According to the study, SS was more cytotoxic than temozolomide (the standard drug used against this type of brain tumor).
If you're considering SS, you should also add organic selenium (selenomethionine) which has been shown to be more effective than SS, at least for some tumor types, according to "Dietary selenium supplementation modifies breast tumor growth and metastasis".
(I have also attached 2 other studies related to selenium and brain tumors)
Cheers,
Mike