I am almost 2 years from my single mastectomy for DCIS and small tumour. I actually had the MRI (over $720) done before surgery as surgeon was a bit concerned she would have to take too much breast to get clear margins. The scan showed that it was bigger than first thought so I opted for mastectomy and it was the best choice in the end and definitely not overkill. I had the single node removal for biopsy and it feels a bit weird sometimes but no pain or long term issues. If there was a bonus to my mastectomy it meant no radiation and as it was low grade I didn’t need chemo either. My biggest regret was not getting implant or recon done at the time so my only advice would be to really explore all your options and what YOU want. My surgeon sort of talked my out of it at the time claiming it was close to Christmas etc and best just to get the breast removed and worry about recon later. Good luck with your scan results xx