Ugh, this is my second attempt to post a response. I hope it doesn't post a bunch of times...
First of all, I can't imagine what you must be going through as you face all of this. I am a neuro nurse, so I'm familiar with the treatments for brain cancer. I'm sure you've already been through some tough times with DH being ill. That is a lot for anyone to deal with, let alone the complication of pregnancy. It might be really helpful for you to have a therapist as you're making these important decisions- if you don't have one already.
I agree with PP about second opinions from another practice. Hope to hear good news from you along the way.