Hi, Amy ~
Although an acoustic neuroma diagnosis is no fun, I'm glad you found this website and the forums.
Vertigo can be very debilitating and, even with small tumors, can be a symptom that drives the AN patient from observation ('watch-and-wait') to treatment, be that radiation or surgery (or both, in some cases). In your situation - mother of an infant and a woman who is very active and rides horses - you're probably even more negatively affected than most by these symptoms. In all honesty, Amy, they usually don't go away or significantly diminish without some kind of treatment - but the tumor
is eminently treatable. I should mention that, today, there is also the possible option of endoscopic surgery to remove acoustic neuromas. This surgical approach is much less traumatic than conventional microsurgery, with an average discharge time of 48 hours, as opposed to the typical 4-6 day hospital stay with conventional microsurgery. Unfortunately, this procedure is not yet widely available but the
Skull Base Institute http://www.skullbaseinstitute.com/ is a pioneer in the approach and has many success stories. Some of our members are 'veterans' of this procedure and will testify to it's success. I believe that it's worth considering.
As for the risks of oncogenesis with irradiation, I believe the statistics are somewhere in the range of 1 in 1000, an almost infinitesimal number. You have to understand and take into account that most doctors are biased one way or the other, be it toward surgery or radiation. That's why you have to do your own, independent research (thank goodness for the internet!) and, when it comes to treatment, 'follow your 'gut'.
As others have stated, this is a surmountable situation. Back in 2006, I was 63 years old and diagnosed with a large (4.5 cm) AN. I underwent microsurgery to reduce the size of the tumor and cut off it's blood supply, then, after a planned 90 day 'rest period', I underwent FSR; 26 'low-dose' radiation treatments over 5 weeks, focused on the remaining tumor. I'm happy to report that I came through both procedures relatively 'unscathed', with only a few very minor deficits that are invisible to others and do not affect my quality of life. Whatever approach you ultimately chose to address your AN, I wish you a similar outcome.
Jim