Safely Delivered Targeted High-dose Irradiation Followed by Adoptive Immunotherapy with Regulatory and Conventional T Cells to Increase Potency of Hematopoietic Stem Cell Transplantation in High-risk Acute Leukemia

This study is testing an advanced bone marrow transplant approach for patients with high-risk acute leukemia, combining targeted high-dose radiation (delivered precisely to the bone marrow) with specially prepared immune cells from a donor, in the hope of improving transplant success and reducing relapse. **You may be eligible if...** - You are between 18 and 65 years old with a diagnosis of acute myeloid leukemia (AML) or acute lymphoblastic leukemia (ALL) - Your leukemia is high-risk or has not fully responded to treatment (some residual disease is present) - You have a suitable bone marrow donor (family, unrelated matched, or half-matched) - You are otherwise healthy enough for a stem cell transplant **You may NOT be eligible if...** - You have significant other health problems that would make transplant too risky - You do not have a suitable donor - You have severe organ dysfunction Talk to your doctor to see if this trial is right for you.