Expert: Dina Q Goldin, Ph.D. - 1/28/2009

Question
I was identified with ACOSTIC NEUROMA in my left ear. I
approached the doctor when i noticed loss of hearing. I
have undergone gamma knife surgery on sep-2007. The size of
my tumor at that time was 1.5x1.0x1.1  i have meen
undergoing MRI every 6 months so as to monitor the size of
the tumor. The latest MRI says the tumor size to be
2x1.5x1.1. I have been reading from the last 10 days
regarding the GAMA knife surgery. I read in one of the
article that the tumor can get swelled after the gama
knife. The true picture of  real growth or the temporary
growth swollen can only be known after 2 years. The maximum
swelling period is from 6 to 18 months, later it can show
the signs of reducing in size. could you please tell me the
information i got is right or it is growth itself.

Answer
The information you got it right.  ANs do tend to swell after gamma knife surgery, so it is a good idea to wait for two years before deciding if the tumor is still growing.  A better indication of progress at this point is whether or not there is necrosis, or death of the AN tissue. This would be indicated by a dark spot in the center of the tumor, and is something your radiologist should be able to tell from the MRI.