When I had partial mastectomy and nodes removed, I also had implant exchange. My radiologist and breast surgeon agreed this was best, as I had very old implants. The rads/partial mastectomy side is firmer , not as soft as the non rads side. At my last follow up appt the plastic surgeon told me to do sort of a exercise/massage thing everyday to prevent hardening. I do have some soreness and mild pain sometimes. As far as shape and the breasts matching, the ps made adjustments in implant size to make sure they match perfectly. Also, my radiation was very precise, above the implant (which is under the muscle), I think it was called IMRT.