More Info from Imaginis

Mel,
I am so sorry to read of your mom's struggles, but she is so very fortunate to have you and your dad helping. You will perhaps have to be demanding in seeking response to your quest for the best care for your mom, but you know the saying, "the squeeky wheel gets the grease"; you're that squeeky wheel now, and your mom NEEDS that grease.
I agree with Paul, a brain MRI is a must, then gather all the reports together and have a discussion with her oncologist to formulate a plan of action. If he is making himself unavailable, you may have to ask for a second opinion to get the ball rolling.
Here's another link to a web site with some good information, and there are additional links provided within the article.
Please keep us posted, there's always someone with a fresh perspective to help.
hugs, Lolly