TY - GEN AU - Khaled Mohammad AbdElsalam AU - Dalia Omar , AU - Ebtessam Saad Eldin , AU - Hisham AbdElall , TI - Role of prophylactic cranial irradiation versus intrathecal therapy only in children with All / PY - 2007/// CY - Cairo : PB - Khaled Mohammad AbdElsalam , KW - Mechaniam of oncogenenis KW - Molecular endemology of childhood KW - Molecular genetics of All KW - Prognostic factoroin All N1 - Thesis (M.Sc.) - Cairo University - Faculty Of Medicine - Department Of Oncology; Issued also as CD N2 - Acute lymphoblastic leukemia is the most frequent malignancy in childhood.Acute leukemia represent aclonal expansion and arrest at a specific stage of normal myeloid or lymphoid hematopoiesis , it constitutes 97perasend of all childhood leukemia , peak incidence between 2 - 5 years of age , accounts for 25 - 30perasend of all childhood cancer ER -