COMPARISON OF 2 STRATEGIES FOR THE TREATMENT OF RADIOGENIC LEUKOPENIAUSING GRANULOCYTE-COLONY-STIMULATING FACTOR

Purpose: Radiation-induced leukopenia can cause a delay or discontinua tion of radiotherapy, This complication can be overcome with the use o f granulocyte colony-stimulating factor (G-CSF), However, an uncertain ty exists regarding the mode of application of G-CSF in patients treat ed with radiotherapy, For this reason, the efficacy of two strategies for the administration of G-CSF in irradiated patients was compared in a prospective randomized clinical study. Methods and Materials: Forty -one patients who developed leukopenia (< 2.5 x 10(9) per liter) while undergoing radiotherapy were treated with G-CSF at a daily dose of 5 mu g/kg. The first group received single injections of G-CSF as requir ed (n = 21), The second group received G-CSF on at least 3 consecutive days (n = 20), An analysis was made of the changes in leucocyte count s, the number of days on which radiotherapy had to be interrupted, and the side effects of growth-factor treatment, Results: An increase in leucocyte values in the peripheral blood was observed in all patients treated with G-CSF. In the group which received G-CSF when required, t wo injections (range: 1-8) were administered in most cases, In the sec ond group, most of the patients received three injections (range: 3-9) , The average duration of therapy interruptions due to leukopenia was 4.8 days (0-28) in the first therapy arm and 2.5 (0-20) in the second arm, The variance in the duration of therapy interruptions between the two groups was not significant (p = 0.2), Radiotherapy had to be term inated in two patients due to thrombocytopenia but the application of G-CSF did not seem to be a reason of decreasing platelet counts, Concl usions: Our results reveal that G-CSF is safe and effective in the tre atment of radiation-induced leukopenia regardless of the mode of appli cation, Because the calculated difference related to radiation treatme nt interruptions has no clinical relevance, both approaches examined i n our study appear reasonable.