Central Nervous System Involvement in Adults with Acute Leukemia: Diagnosis, Prevention, and Management

Recent treatment advances in both acute myeloid leukemia and acute lymphoblastic leukemia have drastically improved outcomes for these diseases, but central nervous system (CNS) relapses still occur. Treatment of CNS disease can be challenging due to the impermeability of the blood-brain barrier to many systemic therapies.The diagnosis of CNS leukemia relies on assessment of clinical symptoms, cerebrospinal fluid sampling for conventional cytology and/or flow cytometry, and neuroimaging. While treatment of CNS leukemia with systemic or intrathecal chemotherapy and/or radiation can be curative in some patients, these modalities can also lead to serious toxicities. In the modern era, prophylaxis with intrathecal chemotherapy is the most important strategy to prevent CNS relapses in high risk patients. Accurate risk stratification tools and the use of risk-adapted prophylactic therapy are imperative to improving the outcomes of patients with acute leukemias and preventing the development of CNS leukemia.