I, too, had one liver spot about the same size. It stayed stable at that size for many months. My doctor began to tell me he thought it was just scarring or "the dead body" of the tumor. I said, Hey, I'll take that, it's just a scar!
So pretty much I went forward assuming that it wasn't active. I think if the doctor used the word remission, and doesn't use it lightly, he would be pretty confident to have used it. I think that is what i would tell people...the doctor told you that you are most likely in remission, but you won't know for absolute certain for another few weeks.
By the way, after about seven months of that little spot on my liver being stable, I had a CT scan and it was completely gone.