Rituximab, Methotrexate, and Tepadina Induction Followed by Etoposide and Cytarabine Consolidation in Primary Central Nervous System Lymphoma

Inclusion Criteria: * Age ≤ 60 years, male or female * Histologically and immunohistochemically confirmed diagnosis of diffuse large B-cell lymphoma (DLBCL) without prior treatment * No evidence of systemic lymphatic or hematopoietic involvement or other systemic disease, based on thorough physical examination and imaging/laboratory tests * Diagnosis meets criteria for Primary Central Nervous System Lymphoma (PCNSL) * Written informed consent obtained from the patient or their legal guardian * Voluntary agreement to participate in the study Exclusion Criteria: * Presence of another active malignancy * Known history of HIV infection or diagnosis of acquired immunodeficiency syndrome (AIDS) * Known allergy to any of the investigational drugs or their excipients * Any condition that, in the opinion of the investigator, may lead to early study termination, including but not limited to: * Severe comorbidities * Significant laboratory abnormalities * Serious social or family circumstances affecting safety or compliance