Looking for information re: scans or ultrasounds after having double mastectomy

I had cancer in both breasts at the time and the first sentinel nodes on both sides. I was advised not to have an auxilliary clearance  of the lymph nodes as it could be detrimental to my quality of life....chance of lymphoedema. I thought that maybe a scan would at least allay any fears. I mentioned this to my Dr. and she said it wasn't necessary.