A relapse of Acute Lymphoblastic Leukemia involving the central nervous system can be serious, but effective treatment options are available. Treatment often includes chemotherapy given directly into the spinal fluid, high-dose IV chemotherapy, and sometimes radiation therapy to control leukemia cells in the brain and spinal cord. In some cases, stem cell transplant or advanced treatments like CAR T-cell therapy may be recommended to reduce the risk of further relapse. Since treatment depends on the patient?s age, previous therapy, and overall health, it is important to consult a hematologist-oncologist for a personalized treatment plan and close monitoring.