HEMATOPOIETIC STEM-CELL COMPARTMENT - ACUTE AND LATE EFFECTS OF RADIATION-THERAPY AND CHEMOTHERAPY

The bone marrow is an important dose-limiting cell renewal tissue for chemotherapy, wide-field irradiation, and autologous bone marrow trans plantion. Over the past 5-10 years a great deal has been discovered ab out the hematopoietic stem cell compartment. Although the toxicity ass ociated with prolonged myelosuppression continues to limit the wider u se of chemotherapy and irradiation, ways are being discovered to circu mvent this toxicity such as with the increasing use of cytokines. This review describes what is known of how chemotherapy and irradiation da mage stem cells and the microenvironment, how cytokines protect hemato poietic cells from radiation damage and speed marrow recovery after ch emotherapy or marrow transplantation, and how various types of blood m arrow cells contribute to engraftment and long-term hematopoiesis afte r high doses of cytotoxic agents and/or total body irradiation.