Ovarian Tissue Cryopreservation in Pre-Pubertal (OTC-Pre Pubertal)

Inclusion Criteria: * Pre- Pubertal Individual * Will undergo imminent surgery, chemotherapy or radiation therapy that has implications on future fertility and reproductive hormone potential: any health condition or malignancy that requires removal of all or part of one or both ovaries, whole abdomen or pelvic irradiation ≥10Gy in post-pubertal girls or ≥15Gy in pre-pubertal girls total body irradiation, and alkylating-intensive chemotherapy: * cyclophosphamide cumulative dose ≥7.5 g/m2 * any treatment regimen containing procarbazine * busulfan cumulative dose \>600 mg/m2 * alkylating chemotherapy conditioning prior to stem cell transplantation combination of any alkylating agent with total body irradiation or whole abdomen or pelvic radiation cranial radiation ≥30 Gy summed alkylating agent dose score ≥3 (Green et al., 2009) cyclophosphamide equivalent dose (CED) ≥ 4,000 mg/m2 (Green et al., 2014) Exclusion Criteria: * Patients with no anticipated oncologic therapies * Post-pubertal individuals * Pregnant children * Children with one ovary * Children deemed high risk for perioperative complications * Patients unable to provide consent/assent (i.e. significant psychiatric problems/cognitive delay)