USE OF RECOMBINANT GRANULOCYTE-COLONY-STIMULATING FACTOR TO TREAT NEUTROPENIA OCCURRING DURING CRANIOSPINAL IRRADIATION

Purpose: To investigate the effectiveness of recombinant human Granulocyte-Colony Stimulating Factor, a hematopoietic growth factor which stimulates neutrophil production, in the treatment of neutropenia caused by Craniospinal Irradiation. Methods and Materials: Four consecutive patients who developed neutropenia (neutrophils less than 1.5 x 10(9)/l in peripheral blood) during craniospinal irradiation for primary intracranial tumors received intermittent subcutaneous injections of Granulocyte-Colony Stimulating Factor. Two of the patients had medulloblastoma, one had a primitive neuroectodermal tumor and the other a pinealocytoma. No patient received prior or concurrent chemotherapy. Results: In all cases peripheral blood neutrophil counts returned rapidly to normal levels following Granulocyte-Colony Stimulating Factor injections and treatment delays were therefore avoided. Platelet counts were unaffected by Granulocyte Colony Stimulating Factor treatment. In one case, slight elevation of peripheral blood monocyte and lymphocyte counts occurred after each Granulocyte-Colony Stimulating Factor injection. No toxicity was encountered. Conclusion: Our results suggest that Granulocyte-Colony Stimulating Factor is a safe and effective treatment for neutropenia caused by extended field radiotherapy.