Expert: Dina Q Goldin, Ph.D. - 11/10/2008

Question
One morning in mid-September I awakened with severe ear pain, facial numbness, and a noticeable decrease in hearing in my right ear. After seeing my internist, an ENT, an audiologist, a neurologist and having an Audiogram, a BSER and an MRI with gad. contrast,I was diagnosed with a 2cm x 2.0 - 2.5 cm AN. I have gait ataxia, some partial facial numbenss and paralysis. My right eye blinking capability is now much slower than my left. I have a moderate-severe hearing loss in my right ear. I have been told by a neurologist and an internist that I would need to have my AN surgically removed. In consultation with an ENT who specializes in AN ( he's on the surgical team), he indicated surgery would be a likely option, but that I still may be a candidate for radiosurgery, although on the borderline. He has also referred me to a brain surgeon who is a part of the AN surgical team. Frankly, I am terrified of major surgery and would like to avoid it if possible. I would prefer Gamma Knife even though I am claustrophobic. I also have VonWillebrand's so that could complicate any invasive surgery. I've read that most tumors under 3cm are treatable with Gamma Knife, but have also received conflicting opinions. Also, do you know if iodine contrast is used or is necessary during Gamma Knife treatment? Is the size AN I have generally able to be treated by GK ?  There is a GK specialist within driving distance of where I live with whom I also plan to consult. I want to get his opinion in addition to the AN specialists who perform surgery or other radiosurgery procedures like CyberKnife. I am 55 y/o female. Thank you for your time today.

Answer
I do not blame you for trying to avoid surgery.  AN surgery is very risky, and in my opinion does not make sense if alternative treatments exist that are much less risky. Tumors your size are certainly treatable by GammaKnife, though it's a good idea to make sure you are working with a team that has done many such AN treatments before, so you can be sure their protocols are all worked out. CyberKnife, or another form of fractionated steretactic radiosurgery (FSR) might be an even better idea; they reduce the chance of post-treatement problems further, especially for larger tumors such as yours.  They may also be a more attractive option for you because the frame is never screwed onto your skull.  Again, my advice is to seek a team that has done many such AN treatments before.

Add-on: after radiosurgery, the tumor tends to swell temporarily while it's dying. The seriousness of your symptoms, compared to most ANs -- such as gait ataxia and partial facial paralysis -- indicate that tumor swelling more risky in your case than in most. My advice is to choose the type of radiosurgery that minimizes the amount of temporary swelling.  This is the reason why GK may be counterindicated for you.  As I wrote, fractionated (multi-session) steretactic radiosurgery (FSR) might be a better option, since research has shown that fractionation reduces the amount of tumor swelling.