If you are considering radiology, I would also ask them that vis-a-vis the location. Ours are small but very near all the other nerves so radiology may pose risks to hearing and facial nerve also since they are all there.
Actually, both types of treatment -- radiation and surgery -- pose risks to nearby nerves. If a nearby nerve is touched during surgery, it may lose some function -- even if it remains anatomically intact. And while radiation may irritate or damage nearby nerves, both CyberKnife (CK) and GammaKnife (GK) have roughly a 1mm margin of error and are not too likely to cause serious collateral damage to nerves not enveloped by the tumor. The facial nerve is very resilient and unlikely to be affected by radiation treatments. The balance and hearing nerves are more sensitive and easily damaged or irritated. But scraping even a small tumor off the balance nerve during surgery can potentially cause as much or more damage as radiation exposure. Meanwhile, radiation avoids many of the potential complications of surgery, including CSF leakage (somewhat common), chronic headaches (about 10-15% risk with retrosigmoid approach), hydroencephalitis (rare), and cognitive or behavioral changes (also rare, and presumably due to retraction of the cerebellum). My point is that both types of treatment involve risks, and damage to nearby nerves is not a concern only with radiation.
With all due respect to Neal, statistics show that there is roughly equal chances of a tumor growing back with either radiation or surgery, so that shouldn't factor into your decision-making. Also, I wouldn't be overly concerned with the long-term effects of radiation: to my knowledge, none of the early adopters of GK and CK have ever observed malignancy caused by radiation on followup visits by previously treated patients, and the history for GK, in particular, is decades long for many patients now. Dr. Chang has treated over 700 patients and has never observed malignancy at the site of a treated tumor. The odds of malignancy occurring are statistically the same as the risk to the general population for getting cancer.
I think it is far better to focus on immediate risks associated with a given procedure than to become fixated on hypothetical risks decades into the future that nobody has yet confirmed.
Toward that end, ask your doctors what are the risks, in percentage terms, associated with all the types of treatments you are considering. In general, retrosigmoid approach (to surgery) carries a higher risk of chronic headaches and hearing loss compared to middle fossa approach. However, middle fossa approach carries a higher risk of damage to the facial nerve (which must be navigated around when using this above-the-ear entry point) compared to retrosigmoid. Translabyrinthine approach ("translab" for short) carries a 100% certainty of deafness following surgery, as it entails the complete removal of all hearing structures (as well the vestibular nerve).
I think W&W should be strongly considered if you are having little or no symptoms. Dr. Brackmann once told me he has seen some ANs stay the same size for over 20 years. All forms of treatment carry very significant risks. But if you are already losing some function (whether hearing, balance or other), then you should not wait too long before getting treated.