Rituximab-Methotrexate-Temozolomide-Thiotepa (RMTT) Regimen As First-line Therapy for PCNS DLBCL

Inclusion Criteria:

• Patients voluntarily joined the study, signed the informed consent, and had goodcompliance;

• Patients with 18 Years to 75 Years(at the time of signing the informed consent);Eastern Cooperative Oncology Group Performance Status (ECOG-PS) score: 0-3;

• Patients with histopathologically confirmed newly diagnosed primary central nervoussystem diffuse large B-cell lymphoma, and there were intracranial evaluable lesions (long diameter greater than 1.5cm, short diameter greater than 1cm);

• Patients who have not received any systemic therapy, except those who use hormonesto control complications

• Expected survival of more than 3 months.

• Female patients of reproductive age should agree that birth control (such asintrauterine device, birth control pills, or condoms) must be used during the studyperiod and for six months after completion; Having a negative serum pregnancy testwithin 7 days prior to study enrollment, and must be non-lactating; Male patientsshould agree to use contraception during the study period and for six months afterthe end of the study.

Exclusion Criteria:

• Patients who have previously received antitumor therapy or targeted therapy

• Patients who have undergone major surgery within the past 3 weeks .

• Presence of severe or uncontrolled comorbid conditions including, but not limitedto, symptomatic congestive heart failure, uncontrolled hypertension, unstableangina, active peptic ulcer disease, or severe hemorrhagic disorders such ashemophilia A, hemophilia B, von Willebrand disease, or history of spontaneousbleeding requiring transfusion or other medical interventions.

• Any active infection requiring systemic antimicrobial therapy within 14 days beforestarting study treatment, including, but not limited to, bacterial, fungal, andviral infections.

• Patients who are pregnant or breastfeeding.

• Current participation in other clinical studies, or initiation of study drugsadministration less than 4 weeks after completion of previous clinical studytreatment.

• Patients with concomitant diseases that, in the investigator's judgment, mayseriously endanger patients' safety or may interfere with the completion of thestudy, or are deemed unsuitable for inclusion for other reasons.