Hope you're well! I just wanted to chime in with what Stella and Gary said regarding radiation and size.
When figuring out what to do, some doctors I spoke with said I was a candidate for radiation, but leaned toward surgery either because of my age (I'm 43 now) or size. Others said I could do whatever I felt best about - my AN was amenable to both. As far as age goes, that's something I think everyone has to research and then sort out their own opinion.
At diagnosis, my AN measured 1.8cm x 2.2 cm x 2.5 cm and at treatment Dr. Chang measured it at 2.6 x 1.8. According to my diagnostic MRI report, it has "mass effect on my brainstem". Fun! Anyway, I had no vertigo, mild hearing loss, ear fullness, tinnitus, and mild face tingling that started right around diagnosis. Like Stella, I felt really strongly about the risks surgery posed. When making the rounds and speaking with doctors, some said it was more difficult to have surgery after radiation, some said a skilled surgeon should not find it much more difficult.
When I met with Dr. Chang previous to treatment, during the course of conversation he said that he's used CK on tumors in the 3.0-3.5cm range (about - I can't remember exactly - it may have been more). Of course there are mitigating factors as each case is different, but it is done.
I had treatment in April, and so far, so good. Though it is possible that the AN swells after radiation treatment, how much and if that then causes an increase in symptoms is very much case by case.
Anyway, no matter what path you choose, it needs to sit right with you! Like everyone else, I urge you to continue to speak with doctors. I sent my MRI to several doctors to look at - some I met with in person, some spoke to me via phone or email. It was helpful for me to evaluate commonalities in answers to my questions as well as points where various professionals had differing statements. Both of those things helped me form an opinion on what step to take next.
Best of luck on your journey!
PS - I can't wait to hear about your MRI, Stella!!