Part or all of an ovary is surgically removed and the outer surface (which contains the eggs) is removed and frozen in strips. For females in whom there is no concern that there might be cancer cells within the ovarian tissue, thawed ovarian tissue can transplanted back. The Oncofertility Consortium is actively researching new ways to use this tissue. Newer techniques are still experimental but may be the best option for females who must start their treatment immediately. This is also the only way to preserve tissue in a pre-pubertal female.