Low dose conditioning regimens and allogeneic bone marrow transplantation

Full text: During the last decades total body irradiation (TBI) has exhibited proved therapeutic success in the treatment of acute (lymphoblastic and myeloblastic) leukemia, chronic myeloblastic leukemia and more than 20 other indications including myeloproliferative diseases and solid tumors. As a conditioning regimen in combination with chemotherapy, TBI plays an important role in the preparation of patients for bone marrow transplantation (BMT). The toxicity of the high dose conditioning regimens has restricted their application in young patients and in patients with good general clinical status. A new strategy for allogeneic BMT has been developed in the last years. Low dose conditioning regimens including fludarabine and 200 cGy TBI, followed by allogeneic blood stem cell transplantation, are applied in patients with advanced hematological and lymphoproliferative diseases, who have been subjected to intensive preceding treatment, with heavy accompanying diseases and with counter indications for conventional myeloablative transplantation. The objective of the present work is to present the contemporary knowledge and experience accumulated in the field of low dose conditioning regimens. The targets, aims and indications for their application are discussed. The role of the graft reaction against the tumor (GvT) for remission attainment is considered in detail. A number of other factors contributing to the therapeutic success are also discussed. The treatment schemes and the achieved therapeutic results are discussed for both the hematological and the lympho- and myeloproliferative diseases. The objects of the report are clinical tolerance, early and late reactions and complications and the therapeutic measures for their reduction