Intrathecal Cytarabine, Methotrexate, and Hydrocortisone for the Prevention of High-Grade Chimeric Antigen Receptor T-Cell-Associated Neurotoxicity Syndrome

Inclusion Criteria: * Written informed consent. Participant or legally authorized representative (LAR) must provide written informed consent prior to any study-specific procedures or interventions * Age ≥ 18 years. All genders, races, and ethnic groups will be included * Must be receiving SOC Yescarta® or Tecartus® in the inpatient setting * Agree to adhere to institutional guidelines for contraception during the first 30 days post CAR-T * Rationale for eligibility criteria based on contraception and pregnancy (both participants and partners of a sperm-producing participant): It shall be known to all participants that the effects of CAR-T or IT chemotherapy on the developing human fetus are unknown. For this reason, persons of reproductive potential must agree to use adequate contraception. Should a participant or participant's sexual partner become pregnant or suspect a pregnancy while participating in this study, the individual should inform their treating physician immediately * Eastern Cooperative Oncology Group (ECOG) performance status ≤ 2 * Platelet count \> 50,000/mm\^3 (μL) * Adequate coagulation tests including international normalized ratio (INR) \< 1.6 and fibrinogen \> 100 Exclusion Criteria: * Active/concurrent diagnosis of any central nervous system (CNS) hematologic malignancy * History or presence of CNS disorder such as poorly controlled seizure disorder (seizure within the 12 months), transverse myelitis, cerebrovascular ischemia/hemorrhage, dementia, cerebellar disease, or any autoimmune disease with CNS involvement * Known history of hypersensitivity to IT chemotherapy * Subject has a contraindication to LP including: * Presence of a posterior fossa mass * Skin infection near puncture site * Uncorrected bleeding diathesis * Suspicion of increased intracranial pressure * Acute spinal cord trauma * Subject is receiving an antiplatelet and/or anticoagulant that cannot be held prior to LP according to best available evidence * Known bleeding disorders * Any other significant medical illness, abnormality, or condition that would, in the Investigator's judgement, make the participant inappropriate for study participation or would put the participant at risk