Walsh & Hoyt: General Considerations

Bone marrow transplantation (BMT) is extremely important in the treatment of malignancy. It is a standard method of treatment for aplastic anemia, thalassemia, combined immunodeficiency disease, and lysosomal storage diseases. In hematologic malignancies, it permits myelolethal doses of chemotherapy by rescue of hematologic function. In addition, it is important in the treatment of diseases in which the marrow may be a limiting factor because of medication toxicity. This may occur during the treatment of tumors such as lymphomas, breast cancer, neuroblastoma, GBM, ovarian cancer, germ cell tumors, and non-small-cell lung cancer. Depending on the indications and the availability of donors, a BMT may be autologous, syngeneic, or allogeneic. An autologous BMT involves harvesting the patients bone marrow and then reinfusing it, usually in conjunction with chemotherapy, TBI, or both. A syngeneic BMT is between identical twins. Autologous and syngeneic transplants usually do not require immunosuppression and have few neurologic complications. An allogeneic BMT is from a donor other than the patient or identical twin and requires concomitant and subsequent immunosuppression. Preparatory regimens for BMT include TBI, usually with less than 2000 cGy, and the use of alkylating agents, usually cyclophosphamide. Neurologic complications occur in 6070% of patients requiring immunosuppression and are the cause of death in 510% of these patients.