Craniospinal irradiation (CSI) of childhood tumors with the RapidArc technique is a new method of treatment. Our objective was to compare the acute hematological toxicity pattern during 3D conformal radiotherapy with the application of the novel technique. | Assessment of the results and hematological side effects of 3D conformal and IMRT ARC therapies delivered during craniospinal irradiation of childhood tumors with a follow-up period of five years