225Ac-DOTA-Anti-CD38 Daratumumab Monoclonal Antibody With Fludarabine, Melphalan and Total Marrow and Lymphoid Irradiation as Conditioning Treatment for Donor Stem Cell Transplant in Patients With High-Risk Acute Myeloid Leukemia, Acute Lymphoblastic Leukemia and Myelodysplastic Syndrome

Inclusion Criteria: * Documented informed consent of the participant and/or legally authorized representative * Assent, when appropriate, will be obtained per institutional guidelines * ≥ 70 years. Note: Patients ≥ 18 years and \< 70 years with active, relapsed or refractory, or high-risk acute leukemia or MDS as defined below. * Karnofsky performance status ≥ 70 * Eligible patients will have a histopathological confirmed diagnosis of hematologic malignancy in one of the following categories : * Acute myelogenous leukemia: * Patients with de novo or secondary disease in unfavorable risk group including poor risk cytogenetics according to National Comprehensive Cancer Network (NCCN) guidelines for AML i.e., monosomal karyotype, -5,5q-,-7,7q-,11q23-non t(9;11), inv (3), t(3;3), t(6;9), t(9;22) and complex karyotypes (≥ 3 unrelated abnormalities), or all patient in intermediate risk groups accept patients with FLT3-NPM1+ disease, OR * Patients with a complete morphological remission (CR) with minimal residual disease (MRD)-positive status by flow cytometry (≥ 0.1% by flow cytometry) or cytogenetic after at least 2 prior induction therapies, OR * Patients with chemosensitive active disease defined as at least 50% reduction in their blast count after last treatment * Myelodysplastic syndrome in high-intermediate (int-2) and high-risk categories per Revised International Prognostic Scoring System- (IPSS-R) * Acute lymphocytic leukemia * Evidence of CD38 expression by flow cytometry AND one of the below * Patients with de novo or secondary disease according to NCCN guidelines for ALL hypoploidy (\< 44 chromosomes); t(v;11q23): MLL rearranged; t(9;22) (q34;q11.2); complex cytogenetics (5 or more chromosomal abnormalities); high white blood cell (WBC) at diagnosis (≥ 30,000 for B lineage or ≥ 50,000 for T lineage); iAMP21loss of 13q, and abnormal 17p, OR * Patients with a complete response (CR) with MRD-positive status by flow cytometry (≥ 0.1% by flow cytometry) or cytogenetics after at least 2 prior induction therapies, OR * Patients with chemosensitive active disease defined as at least 25% reduction in their blast count after last treatment * Patients with myelofibrosis (primary or secondary, including post-polycythemia vera and post-essential thrombocythemia myelofibrosis) may be eligible for enrollment if they meet criteria for high-risk disease and are planned for allogeneic hematopoietic cell transplantation. * Eligible patients include those with: * Accelerated-phase or blast-phase myelofibrosis, defined as 10% to 19% blasts or ≥20% blasts, respectively, in peripheral blood or bone marrow * High-risk chronic-phase primary or secondary myelofibrosis, defined as disease meeting transplant-appropriate risk criteria by a validated MF prognostic model, including DIPSS intermediate-2 or high-risk; DIPSS-plus intermediate-2 or high-risk; MIPSS70 intermediate, high, or very high-risk; MIPSS70-plus or MIPSS70-plus version 2.0 intermediate, high, or very high-risk; GIPSS intermediate-2 or high-risk; or MYSEC-PM intermediate-2 or high-risk for post-polycythemia vera or post-essential thrombocythemia myelofibrosis. Patients may also qualify based on adverse clinical, cytogenetic, or molecular features supporting high-risk disease biology and transplant candidacy, including complex karyotype, monosomal karyotype, very high-risk karyotype, high molecular risk mutations, transfusion-dependent anemia, thrombocytopenia, circulating blasts, constitutional symptoms, or symptomatic splenomegaly despite standard therapy * Suboptimal response, progression, or intolerance to prior JAK inhibitor therapy, defined as failure to achieve adequate spleen or symptom response after an appropriate trial of therapy, generally at least 12 weeks at an appropriate or maximally tolerated dose when clinically feasible; loss of prior spleen or symptom response; worsening splenomegaly; persistent or worsening constitutional symptoms attributable to MF; worsening cytopenias or transfusion dependence; progression to accelerated-phase or blast-phase disease; emergence of adverse cytogenetic or molecular features; or inability to continue JAK inhibitor therapy due to treatment-related toxicity. A minimum duration of JAK inhibitor exposure is not required when the treating investigator determines that continued therapy is not clinically appropriate due to rapidly progressive disease, accelerated-phase or blast-phase transformation, clinically significant cytopenias, intolerance, or urgent need to proceed to allogeneic HCT. The rationale for early determination of JAK inhibitor failure or inability to continue JAK inhibitor therapy will be documented in the medical record. * Persistent disease burden, including persistent splenomegaly, circulating or marrow blasts, transfusion dependence, cytopenias attributable to MF, leukocytosis, thrombocytopenia, adverse cytogenetic or molecular features, extramedullary hematopoiesis, or progression despite standard therapy, may support high-risk classification but does not constitute a separate eligibility criterion unless the patient also meets the defined advanced-phase, validated risk-model, or JAK inhibitor failure criteria above. \*\*See Appendix F: Defined Risk Scoring Systems in MF * All patients must demonstrate CD38 expression on disease-relevant cell populations (bone marrow and/or peripheral blood) as assessed by flow cytometry or an equivalent validated assay prior to enrollment. Clinical Laboratory and Organ Function Criteria (To be performed within 30 days prior to Day 1 of protocol therapy unless otherwise stated) or (acceptable windows for tests are indicated in the Study Calendar Section 10.0). * A pretreatment measured creatinine clearance (absolute value) of ≥ 60 ml/minute (To be performed within 30 days prior to day 1 of protocol therapy unless otherwise stated) * Patients must have a serum bilirubin ≤ 2.0 mg/dl (To be perfo