Erythropoietic recovery in human after extended field radiotherapy: Ferrokinetic studies of patients treated by radiotherapy followed by autologous bone marrow transplantation and of patients treated by moderate doses (20 Gy) of radiotherapy

Abstract

The ability of human irradiated bone marrow to provide suitable environment for migrating stem cells has been studied in four patients. These had received chemotherapy plus doses of 40 Gy to thoracic vertebrae and sternum, followed by autologous bone marrow transplantation. The erythropoietic activity in the non-irradiated areas was increased but it was low in irradiated areas at 3.5 weeks and undetectable at 6 months after autotransplantation. This shows that no nidation of migrating stem cells actively contributed to bone marrow regeneration after 40 Gy and suggests the existence of environmental lesions. No extramedullary erythropoiesis and no bone marrow extension were found in these patients. Four patients who had received doses of 20 Gy to extended bone marrow volume were submitted to ferrokinetic studies from one to 18 years after radiotherapy. In non-irradiated areas the erythropoietic activity was within the normal range. In irradiated areas, it was significantly lower than in the non-irradiated areas and was intermediate between the erythropoietic activity in the sacrum of six healthy control subjects and in the irradiated areas of the four autografted patients. Bone marrow extension was found in these patients. This study suggests that bone marrow recovery after irradiation might not be an all-or-none phenomenon. It would be of interest to better document the dose-effect relationship.