Comparison of Long-Term Neurocognitive Outcomes in Young Children With Acute Lymphoblastic Leukemia Treated With Cranial Radiation or High-Dose or Very High-Dose Intravenous Methotrexate

Purpose Cranial radiation therapy (CRT) is associated with neurocognitive morbidity in survivors of childhood acute lymphoblastic leukemia (ALL). For most patients, CRT has been replaced with intensified systemic and intrathecal chemotherapy, often including methotrexate (MTX). The impact of chemotherapy-only protocols on neurocognitive outcomes is unclear, and the importance of systemic MTX dose has not been established. Patients and Methods Seventy nine of 120 eligible children diagnosed with high-risk ALL between the ages of 1.0 and 4.9 years participated in this retrospective cohort study. All patients were treated on a uniform chemotherapy protocol with one of three modalities of CNS prophylaxis, depending on their treatment era. In addition to intrathecal therapy, CNS-directed therapy consisted of CRT (18 Gy in 10 fractions) in 25 patients, high-dose intravenous (IV) MTX (8 g/m2 × 3 doses) in 32 patients and very high-dose IV MTX (33.6 g/m2 x 3 doses) in 22 patients. Participants completed tests of ...