Is it possible to get the same size breast with reconstruction
It is difficult to say without an exam. Many times a small reduction of the unaffected breast is necessary to achieve symmetry if your breasts are that large
The breast is a complex organ in which the blood and nerve supply to the skin travels through the breast tissue. When the breast tissue is removed in a mastectomy, the skin then survives on blood that comes randomly from the periphery. The bigger the skin envelope, the bigger the risk that some of the skin may not survive. If women have very large or very droopy breasts, it is often better to reduce the amount of skin with a reduction or breast lift. The largest breast implant is 800cc in silicone, and 960cc in saline. That converts to about a 38 D-DD.
If you have excess fat in your abdomen, a plastic surgeon might suggest creating a free flap of that tissue to reconstruct the breast. But, again, the larger the amount of tissue transferred, the higher the risk that some of the tissue might not survive due to blood supply. You should consult with a board-certified plastic surgeon well experienced in breast reconstruction to see what your options could be.
Reconstructing a breast to size 38H would be exceedingly difficult under perfect conditions. Depending on tumor location, you may be a candidate for an oncoplastic reduction.