Do you know why the second doc changed her opinion (you say she did it with no new knowledge)? Did she change because you told her of the first docs opinion or did she she change without any outside influence?
MD is indeed considered one of the best with top rated docs so I would give it a lot of weight, but perhaps a further check to see if this was just one Doctor's opinion or the direction of the hospital in general. It sounds like a big change in treatment direction if it is as I was also told that chemo was done to hit the microscopic cancer that might or might not be there.
Any of the medical people here know more?