Epoetin-alpha in radiotherapy

Sixty per cent of oncologic patients need radiation therapy for cure or pal liation. In fact, in most neoplastic diseases, a better local control posit ively impacts on disease-free survival and overall survival. The efficacy o f radiotherapy depends on several factors: while some are tumor-related, ot hers are host-related. Radiobiological phenomena are also important: ionizing radiation is respons ible for cell damage (double rupture of DNA chains), mostly an indirect mec hanism with the formation of free radicals. Their toxic action is enhanced by the oxygen partial pressure at the cellular level. A number of studies have confirmed that good tissue oxygenation is a functi on of a high hemoglobin level in the peripheral blood (Hb greater than or e qual to 13g/dL). Unfortunately, these values are rarely present in oncologi c patients due to the disease-related toxicosis as well as to the therapy i nduced hematologic toxicity. The treatment of anemia is free of risk for the recent developments in tech nology which with gene cloning and the technique of recombinant DNA has all owed the production of human recombinant erythropoietin. Erythropoietin is produced by the interstitial cells of renal tubules in re sponse to hypoxia. It prevents apoptosis and promotes erythroid proliferati on and differentiation with consequent reticulocyte release and hemoglobin synthesis. It is not completely understood whether the efficacy of radiotherapy depend s on hemoglobin values present at the start of irradiation (often less than 12-13 g/dL) or on the higher ones observed during and at the end of radiot herapy. Therefore, preventive systemic erythropoietin therapy in non anemic patient s In terms of costs/benefits is at present non sustainable. To the contrary, in patients undergoing radiotherapy to extended fields or aggressive multimodal treatments, for the higher risk of anemia, the early use of this treatment can be hypothesized in case of initial anemia to impr ove therapy compliance and prevent negative conditioning of results. Keeping in mind that grade 1 minimum toxicity for red cells, according to t he Radiation Therapy Oncology Group (RTOG) is equal to 11gHb/dL we think th at this value can be considered as cutoff to start erythropoietin therapy.