Transplantation schema. Patients received an age-adapted myeloablative conditioning regimen based on TBI, either fractionated (9 fractions delivered twice per day for 4.5 days; total dose, 13.5 Gy) or single dose of 8 Gy with lung shielding, for those age up to 50 years or based on TMLI for those age 51 to 65 years. TMLI was administered by helical tomotherapy in 9 fractions delivered twice per day for 4.5 days. TMLI target volumes were skeletal bones for total marrow irradiation (total dose, 13.5 Gy) and major lymph node chains and spleen for total lymphoid irradiation (total dose, 11.5 Gy). TBI or TMLI were followed by thiotepa (5-10 mg/kg), fludarabine (150-200 mg/m²), and cyclophosphamide (30 mg/kg). After conditioning, all patients received an infusion of 2 × 10⁶/kg donor Tregs on day −4 followed by 1 × 10⁶/kg Tcons on day −1 and a megadose of positively purified CD34⁺ hematopoietic progenitor cells on day 0. No pharmacological GVHD prophylaxis was administered posttransplantation.