Not surprising. They can actually get larger (mine was at 6 months) and/or show a central area of darkening (mine did). Although some people say that the darkening is necrosis, my doctor didn't completely agree with the terminology, but that is a positive outcome. I think the most frequent outcome is no change at all--the tumor is "stable" or "controlled". I think you have to wait 2+ years before you can begin to conclude anything. During that time, anything can and does happen.