Hi and welcome.
Although not knowing the specifics to your dad's AN situation (ie: size of tumor, exact location of tumor, etc), I can share that if you are near OKC, you have a terrific facility for treatment in St. Anthony Hospital.
If your's dad's tumor size is small and if he were to decide a radiation option for treatment, one of the best AN radiation doctors (well known on these forums) is located right there. Dr. Clinton A. Medbery, III, M.D.St. Anthony Hospital Cyberknife Center(405) 272-7311, buddy@swrads.org or Mail to:Clinton A. Medbery, III, M.D.Southwest Radiation Oncology1011 N. Dewey Ave. #101Oklahoma City, OK 73102
I know of some that have been treated there that are active here on these forums (or have been in the past) and hope they chime in soon with their thoughts as well.
Again, welcome... and know... we are here to help.
Phyl