DCIS and mastectomy

I have a recent diagnosis of DCIS ,a  lumpectomy was done . 2mm margins on two sides, no other calcifiactions on other breast or affected breast.
My options are
1-further excisional surgery to make sure no  remaining DCIS present followed by RT. My breasts are large so they can tolerate the repeat surgery.
2-I have been given the option of mastectomy bilateral.  with a DIEP from the abdomen,

Wouldn't a unilateral mastectomy of the affected breast be almost as good. I realize the remaining breast has a chance of developing DCIS and I would need close survelliance of the remaining breast and also tamoxifene Rx.because the Estrogen receptors were positive. I am 56 and enjoy the sexuality my breasts afford me so I am thinking one good one is better than two "breast mounds" as the plastic surgeon called the resulting breast reconstruction with nipples removed.

[Cleveland Clinic]

Dear Joennie:  In a situation of DCIS, without any invasion, a bilateral mastectomy might be considered a very aggressive approach unless there is genetic testing that suggests a higher than average risk.  In general, a reexcision with radiation therapy or a unilateral mastectomy (with or without reconstruction) would be the options as far as treatment is concerned – and the choice would be a personal one.  I would wonder if the option of bilateral mastectomy option is based on providing “equal” mounds of tissue for purposes of cosmetic result.  You may want to discuss this further with your plastic surgeon and/or consider a second plastic surgery opinion.