I was DX Ewings left Maxilus sinus. After three round sof initial chemo, it shrunk, and then I went for surgery. I finished Radiation Therapy, and almost 1 year of Chemo this month (AUG). If you have good margins and the tumor shrinks before surgery, your chances of a complete remission are almost total. Keep on track witht the chemo, don't take breaks betweek cycles, eat well, stop smoking and drinking if you have to as well.
Good luck to you.