What I have observed, ANSkeeterMcGee, in a totally non-scientific approach is that someone on the forums will choose to have surgery to remove their acoustic neuroma, and it will be wildly successful with minimal symptoms, and then they will recommend that approach for everyone else.
And then someone else will have the exact same surgical approach and will have terrible results. They will have awful facial paralysis, terrible migraine headaches, and loss of hearing, and they will tell everyone on the forums not to have that surgical procedure.
Then there will be someone who had GammaKnife, and everything went very well. And 10 years out, they are still doing well. So, you know what they do? They recommend GK to everyone. But there will be someone else who had also had GK, but have experienced nothing but problems, including loss of hearing. And they will warn others not to do GK.
And then there are others who elect to have CyberKnife, and everything went very well. And you know the routine by now: they recommend CK to everyone else on the forums. But then there's the person who had CK and everything seemed to have gone wrong. And they warn everyone not to ever have CyberKnife.
How can it be that with every treatment approach, there are those who have had a wonderful experience and there are those who suffered miserably? I believe the difference comes down to two things: First, while our acoustic neuromas have certain similarities, there are also a lot of differences. So what works for one person with one approach might not work as well for another person's whose acoustic neuroma might be bigger or smaller or is located in a different area.
And then, secondly, and maybe more importantly, the experience that the practitioners have with any approach varies widely. So, someone can have surgery with one very experienced acoustic neuroma neurosurgeon and have great success. Another person may have the same surgical approach with another neurosurgeron who only does one or two acoustic neuromas a year. This doctor is not very experienced with it and nicks a nerve, and the patient suffers terrible facial paralysis. The difference is not in the approach; the difference is in the skill and experience of the neurosurgeon.
The same thing is true with radiation. One person will have gamma knife therapy with a practitioner who treats hundreds of acoustic neuroma patients, and he/she has great success. Another person will choose to have CK, and they think it's a better approach because it is fractionated. However, poor treatment whether it is done once (as in GK) or done multiple times (as in CK) is still poor treatment and can have terrible consequences.
Unfortunately, what I often see with those who had terrible results with their treatment is that they never considered the best in the field. They often go to the hospital which is the closest to where they live and have an inexperienced doctor treat them. And then when the results are bad, they blame the treatment approach rather than the skill and experience of the practitioner. So many place their brains in the hands of whomever their ENT recommended rather than to search for themselves someone who is highly experienced and is dealing with acoustic neuromas every day.
ANSkeeterMcGee, you specifically asked for data. I have not given you any data on purpose. If you truly want data, then I encourage you to contact the Mayo Clinic. They have a lot of data on the various approaches. However, what is more important to me is not the data because the data can be skewed by in experienced practitioners. What is more important to me is finding someone you trust who is very experienced treating acoustic neuromas. Can something still go wrong with a highly skilled doctor? Yes, but he/she is way less likely to have poor results compared to the person who rarely treats acoustic neuromas.
Be cautious of the place where they purchase a new radiation device (whether GK or CK), and they are now advertising that they offer treatment for acoustic neuromas. And every practitioner who works in that department cannot wait to try to new machine. The problem is that they have no experience using it. Their results will not be as good as another place where they treat hundreds of acoustic neuroma patients. Experience and skill will trump inexperience no matter which treatment approach is chosen.
That's my long answer to your very good and simple question.