KW -
I've never heard of radiation "damaging surrounding tissue". Does the doctor your wife saw - who I assume will be doing the surgery - actually do radiation?
The majority of docs are very biased about treatment options. Those who do surgery, tend to recommend it. Those who do radiation, tend to recommend it. It's very important to get a well-rounded opinion and IMO crucial to see a doc who does both so you don't get his/her bias.
Although waiting for treatment might not be a great option for your wife - with her AN touching the brainstem - surgery doesn't have to be immediate. She'd have time to consult with another doctor (or two) if she wanted to.
That said, if she is comfortable with her doctor and comfortable with the idea of surgery, then she may want to just go with it. Treatment option is a personal choice and I'm not knocking hers - I had surgery myself - I just want to make sure she's fully informed.
I had retrosigmoid but didn't have the same symptoms as your wife. I had diminished hearing and a feeling of fullness in my ear as well as balance issues. But different people experience different symptoms. Retrosigmoid has a reputation for causing headaches post op - some of them severe - but I don't experience them. As with symptoms, post op side effects differ from patient to patient. There are certain commonalities, but not everyone "gets" everything.
If you or your wife never requested informational brochures from the ANA, please do so - you'll find them very helpful.
Jan