Abstract: Small doses of ionizing radiation reduced the neoplastic transformation, the tumor development and growth, and obtained therapeutic efficacy on clinical trial in lyphosarcoma patients. Its mechanism is currently unclear. It can be related to enhanced ability of antioxidation in organism, reduced chromosomal damage and increased eliminating damaged cells. Partial tumors destroyed by small doses of ionizing radiation very discovered for leukemia and polycythemia were treated to open a novel approach.