Hello your situation is like mine but my wife is only 43 so she can take the treatments shes tough yet.
Your Grandpa,im so sorry but wouldnt you be happy if you lived to 86!!!!? hek i would be im 45 my name is Mike,my expectations,pain patch is strong dangerous medicine they have dependancy problems ,but it is important VERY IMPORTANT that he is comfortable.
I know nothing of this cyber knive you speak of,expect its gonna get worse before better,i would ,dont wanna set yuorself up!! Except it its part of life we come we go,As i heard at 1 of way to many funerals for my age,was that life is like a series of doorways,and that death was just another doorway,made sense then does now.
I do not want to tell you that negative stuff but face it. :o)