Pat .....
You have touched on an important part of the decision-making process ..... whether to use radiation to arrest the growth of the tumor or surgery to remove it. Part of the decision rests on exactly where the tumor started growing, not just the actual size. Also the symptoms you are experiencing and whether or not they are changing, especially of they are getting worse and how fast.
I, for one, did not really have the option of radiation, partly because of the size, but more importantly the speed with which it was growing. I am not sure I would have been able to psychologically deal with leaving it in my head, even if I had been given that option. But, that is a personal thing ..... no one should try to sway you towards either way. As you can read on this Forum, there are many success stories for both radiation and surgery. After you know all of the facts, you need to do what feels right for you.
Thoughts and prayers. Keep us posted!
Clarice
P.S. Pittsburgh has an excellent reputation for success with gamma knife.