PD-1 Inhibitor Intraperitoneal Perfusion Combined With PRaG Therapy for Malignant Ascites

Inclusion Criteria: * Patients \> 18 years of age. * Pathologically diagnosed malignant tumor abdominal metastasis with malignant ascites (or ascites exfoliative cytology confirmed malignant peritoneal effusion), without brain metastasis or liver metastasis. The patient had newly diagnosed abdominal metastasis with malignant ascites for no more than 1 month. * Progression on at least one line of prior standard therapy or unsuitability for standard systemic therapy. * No congestive heart failure, unstable angina pectoris, unstable arrhythmia within the past 6 months. * Eastern Cooperative Oncology Group (ECOG) Performance Status: 0-3, and life expectancy 2 months or more. * No previous severe hematopoietic function, heart, lung, liver, kidney dysfunction and immunodeficiency. * One week before enrollment, the absolute value of peripheral blood T total lymphocytes ≥ 0.5 times the lower limit of normal, the absolute number of CD8 + T cells ≥ 200/uL, neutrophils ≥ 1.0 × 109/L; AST and ALT ≤ 3.0 times the upper limit of normal; creatinine ≤ 1.5 times the upper limit of normal or creatinine clearance ≥ 50 mL/min, serum albumin ≥ 30 g/L. After treatment, the indicators are allowed to reach the above criteria and last for 2 weeks. Transfusion therapy or granulocyte stimulating factor therapy is not allowed before treatment. * Patients must have the ability to understand and voluntarily sign an informed consent form. Exclusion Criteria: * Pregnant or lactating women. * Patients wit…