I had a small invasive ductal carcinoma and had lumpectomy and sentinel node biopsy. Node was clear but pathology showed DCIS to all margins of the removed tissue, none of which showed up on MRI. I was offered wider excision with radiation or mastectomy but it was explained that after excision, ongoing screening would be difficult because the DCIS wasn't detectable on imaging.
I have chosen mastectomy because it would always be playing on my mind, is there more, will it invade and when? I have also chosen double to reduce further risk. But that's just me, I'm comfortable with losing my breasts in exchange for better mental health, and others may choose differently. All the very best with your treatment xx