Osteosarcoma. Clinical features and evolving surgical and chemotherapeutic strategies. Osteosarcoma is the most common neoplasm of bone in children and adolescents. The first effective therapy became available in the early 1970s, and although controversy existed for several years regarding the relative value of aggressive multiagent chemotherapy, presently about 60% of patients with resectable primary tumors and no metastases at diagnosis will be cured. New imaging methods, including computerized tomography, magnetic resonance imaging, and radionuclide techniques, that are sensitive to changes in local tumor perfusion have improved the ability to define the extent of tumor and the response to chemotherapy, and to plan surgery. Although amputation historically has been the primary method for local tumor control, newer surgical techniques and endoprosthetic devices, coupled with effective preoperative chemotherapy, have offered less radical surgery for 50% to 80% of patients with osteosarcoma. New therapeutic agents, including ifosfamide and the immunosuppressive drug, muramyl tripeptide phosphatidylethanolamine, hold promise for improvement in the cure rate of osteosarcoma. 