L.G.
I'll pray for you. This is very difficult and my heart goes out to you. My husband had a cancer that spread to his brain. He did the surgery and the radiation but he died anyway. My husband did not want chemo as the original cancer could not be cured with it.
You husband's cancer may be curable with chemo or other methods. Make certain they know whether it is in his liver as well. They use a cold knife that doesn't break the skin to destroy cancer of the liver. You may have to sign for the brain surgery as he may be incoherent or if he has another seizure he might be unable to speak for himself. There are medications that can control the seizures. My husband also used homeopathic Hyoscyamus to control and come out of the seizures. I had to give it to him as he would be too convulsive to get it himself.
Talk it over with him and find out what he wants to do. There are things in alternative medicine that do work. He would have to know if he can do them and they are typically not covered by insurance.
Keep looking for what might work. Often the doctors give up on a patient who could live with the right treatment.