Treatment of Newly Diagnosed Standard Risk Acute Lymphoblastic Leukemia in Children

\<Inclusion Criteria\> * Newly diagnosed pediatric/adolescent acute lymphomblastic leukemia patient with NCL standard risk that stratifies all 1-4 of following 1. 1 year old ≤ Age \< 10 years old 2. white blood cell at initial diagnosis \< 5x10\^10/L (50,000uL) 3. No testis involvement 4. Satisfaction of following organ functions A. Kidney function (satisfies i or ii) i. Creatinine clearance (or radioisotope-measured GFR) ≥ 70mL/min/1.73m2 ii. Creatinine value according to age/sec satisfies the following: 1 to \< 2 years: Male: 0.6 / Female: 0.6, 2 to \< 6 years: Male: 0.8 / Female: 0.8, 6 to \< 10 years: Male: 1 / Female: 1, 10 to \< 13 years: Male: 1.2 / Female: 1.2, 13 to \< 16 years: Male: 1.5 / Female: 1.4, ≥ 16 years: Male: 1.7 / Female: 1.4 However, subjects who meet the selection criteria within 1 week before registration after receiving appropriate conservative treatment, including fluid therapy, can be registered. B. Liver function i. Direct bilirubin \< 3.0mg/dL \<Exclusion Criteria\> 1. Steroid administration within 2 weeks before the registration 2. t(9;22) or t(4;11)(q11;q23) or chromosome \< 44 or iAMP21 or t(17;19)/TCF3-HLF 3. Newly diagnosed T cell ALL 4. One of the following syndromes: Down syndrome, Bloom syndrome, ataxia-telangiectasia, Fanconi anemia, Kostmann syndrome, Shwachman-Diamond syndrome, or other bone marrow failure syndrome 5. Burkitt leukemia/lymphoma 6. In the presence of electrocardiographic findings suggesting uncontrolled cardiac dysfunction (e.g., unstable ischemia, symptomatic arrhythmia, congestive heart failure) or congenital long QT syndrome 7. When the clinical trial subject(or legal representative) does not consent or is unable to give written consent