Hi Fender,
I am in the midst of a 5.5-week, 28-treatment fractionated radiation plan at OU Stephenson Cancer Center. My AN is 1.5cm right side, but I am young (32) and still have excellent hearing. After consulting with my tumor board (neurotologist, neurosurgeon and radiation oncologist) I decided this was the best decision for me because any other option, including Gammaknife, would have almost certainly caused significant to total hearing loss in my right ear.
I am writing to say that lots of people on this message board will try to tell you what's best for you, but only you know what's best for you. My radiation is a piece of cake, aside from the minor inconvenience of a 3-hour round-trip drive every day for six weeks. At first I was leaning toward retrosigmoid surgery, but all options offer pros and cons; it's a matter of deciding what is most important and what you can handle at this time. It's also a matter of which doctor you think is looking out for your best interests. I was lucky enough to have three doctors very experienced in ANs agree on one treatment plan.
Good luck in your decision-making – it certainly is not an easy one.