18-FLT PET/MR Imaging to Predict Graft Failure and GVHD in Bone Marrow Transplant Patients

Allogeneic HSCT is potentially curative for numerous high risk hematologic malignancies and offers several advantages over traditional chemotherapy. First, higher doses of cytotoxic chemotherapy and/or irradiation can be given since patients are subsequently rescued from the severe myelosuppression induced by the pre-transplant conditioning regimen by the infusion of healthy hematopoietic stem cells. Second and perhaps more importantly, mature T cells contained in the graft are able to mount immune responses against residual cancer cells surviving the conditioning regimen due to major and/or minor MHC disparities between the donor and recipient. Unfortunately, the allo-immune responses driving the GVL effect are typically not specific for malignant cells. As a consequence, donor immune cells attack normal host tissues resulting in a process known as acute graft-versus-host disease (GVHD). Acute GVHD is primarily T cell driven, usually occurs within the first few months after transplant, and results in skin rash, diarrhea, cholestatic liver damage, and, on occasion, acute lung injury.