Despite recent advances in the targeted therapy of AML, the disease continues to have a poor prognosis. Allogeneic hematopoietic stem cell transplantation (alloSCT) remains to be the curative therapy option for fit patients with high-risk disease. Especially patients with relapsed or refractory (r/r) AML continue to have poor outcomes. Myeloablative total body irradiation (TBI) based conditioning can be used in AML patients refractory to multiple lines of standard therapy, but the optimal conditioning regimen remains unclear for patients considered to be chemotherapy- refractory. Feasibility of C-X-C-motif chemokine receptor 4 (CXCR4)-directed endoradiotherapy (ERT) has previously been demonstrated in AML patients with CXCR4 expression on leukemic blasts.