PET/CT-Guided Maintenance Therapy in Previously Untreated MZL

Inclusion Criteria: Age ≥18 years ECOG performance status (PS) 0-2 Life expectancy of no less than 12 weeks Marginal zone lymphoma (MZL) confirmed according to the WHO 2022 classification of lymphoid neoplasms, including all three subtypes: splenic MZL, nodal MZL, and extranodal MZL Presence of a treatment indication for MZL per NCCN guidelines, and no prior systemic therapy for MZL (hormonal therapy and anti-infective treatment excepted) Adequate organ function, as defined by the following criteria (except when attributable to lymphoma involvement): Hematologic function: 1. ANC ≥1.0×10⁹/L 2. Platelets ≥75×10⁹/L 3. Hemoglobin ≥80 g/dL Biochemical function: 1. Total bilirubin (TBIL) \<1.5×ULN 2. ALT and AST \<2.5×ULN (\<5×ULN for patients with hepatic involvement) 3. Creatinine clearance ≥40 mL/min (Cockcroft-Gault formula) Women of childbearing potential must have practiced reliable contraception or have a negative pregnancy test (serum or urine) within 7 days before enrollment, and must agree to use appropriate contraception during the study and for 8 weeks after the last dose of study drug. Men must agree to use appropriate contraception or have undergone surgical sterilization during the study and for 8 weeks after the last dose of study drug Voluntary participation with signed written informed consent and willingness to comply with follow-up Exclusion Criteria: Central nervous system involvement Prior or concurrent malignant tumor that has not been cured, except adequately treated basal cell carcinoma of the skin, carcinoma in situ of the cervix, and superficial bladder cancer Presence of any of the following cardiovascular diseases: myocardial ischemia or myocardial infarction of grade II or above, uncontrolled arrhythmia (including QTc interval ≥450 ms in males and ≥470 ms in females), New York Heart Association (NYHA) class III-IV heart failure, or left ventricular ejection fraction (LVEF) \<50% on echocardiography Coagulation abnormalities (INR \>1.5, or prothrombin time (PT) \>ULN + 4 seconds, or APTT \>1.5×ULN), a bleeding tendency, or ongoing thrombolytic or anticoagulant therapy Arterial or venous thromboembolic events within 12 months before enrollment, such as cerebrovascular accidents (including transient ischemic attack, cerebral hemorrhage, and cerebral infarction), deep vein thrombosis, and pulmonary embolism Known hereditary or acquired bleeding or thrombotic diathesis (e.g., hemophilia, coagulation disorders) Major surgery, severe traumatic injury, fracture, or ulcer within 4 weeks before enrollment Factors that significantly affect the oral absorption of drugs, such as inability to swallow, chronic diarrhea, and intestinal obstruction Active infection requiring antimicrobial therapy (e.g., antibacterial or antiviral agents; excluding anti-HBV therapy for chronic hepatitis B and antifungal therapy) Active hepatitis B (HBV DNA ≥2000 IU/mL or 10⁴ copies/mL) or hepatitis C (positive anti-HCV antibody with HCV RNA above the lower limit of detection of the assay) History of psychotropic substance abuse that cannot be abstained from, or presence of a psychiatric disorder Known allergy to 68Ga-Pentixafor or 18F-FDG Inability to undergo PET/CT examination for other reasons (e.g., claustrophobia, inability to lie supine) Pregnant or lactating women; patients of childbearing potential who are unwilling or unable to use effective contraception Any other condition that, in the judgment of the investigator, may affect the conduct of the clinical study or the assessment of study results.