I, too, have spent a lot of time looking for supplemental "assists". There are two that appear to be very promising (1) tumeric or curcumin. A doctor at MD Anderson in Houston has been working with this for many years. It is available in megadoses (1500 mg capsules) from him at MDAnderson. The second is avoiding foods rich in Omega 6 fatty acids.
The gist of it seems to be that tumors grow back through well nutured blood vessels and the tumeric appears to stop that regrowth. type curcumin and glioblastoma in your web browser.
My husband's oncologist read the material I printed and told me to go ahead, that anything that helps is not wrong to use.
I read that the tea is not good for this type of cancer.
Good luck, and share. We are the advocates.