Hi Lise and welcome.
Well, I'll chime in as one that was treated with CK in Boston at Beth Israel Deaconess. I can well understand your sister's comments about Boston.... as a reality is... Boston is a medical mecca, offering all choices of AN treatments within a short distance. I know of MANY successful AN surgeries at MGH/MEEI.... successful CK treatments at BI.... GammaKnife Radio at Tufts, terrific surgeons at Brigham & Woman's, etc.
If you have questions specific to Boston, myself or others here in the area can help answer questions.... and hoping some of the Boston gang chimes in for help.
Since your AN is deemed "small", you do have time to research your options. Take that time, do the homework... and if it becomes overwhelming, take a step back to take a deep breath. You are not in an emergent situation so get to know folks here and the info we can share. In the long run, it'll be helpful in helping you make the best, well-informed decision you can for your particular situation.