Hi Kim -- sorry to hear about your Dad's diagnosis. MD Anderson is one of the top brain tumor centers so you are in a good place. The standard first line treatment is surgery to remove as much of the tumor as possible (if it's operable, sometimes they can only do a biopsy), followed by radiation and concurrent Temodar as others have stated. Temodar is working for my husband. There are some people who don't respond as well and there are other options if Temodar doesn't work for your Dad.
Don't dwell on the statistics you may read about GBM, they are just that, statistics, and everyone is so different. My thoughts and prayers are with you, your Dad, and family -- maintain hope.
My husband just finished his sixth cycle of the 5/23 Temodar and he just left for the golf course, he's playing in a tournament this weekend.
Nancy
**husband dx 8/07 GBM, surgery, radiation/Temodar, currently on 5/23 Temodar