Iodine-125 Seed Implantation Therapy for Locally Advanced Pancreatic Cancer

Inclusion Criteria: * Age: 18-80 years * Cytologically or histologically confirmed pancreatic adenocarcinoma * Inoperable locally advanced pancreatic cancer based on American Joint Committee on Cancer (AJCC) staging system (8th ed) (without distant metastasis) * Single tumor size≤ 6 cm * Karnofsky performance score （KPS）≥60 * Estimated survival ≥3 months * Without other several comorbidity * Participants must have adequate organ function: * WBC≥3×109/L; HGB≥90g/dL; PLT≥50×109/L * Aspartate Transaminase (AST)/alanine aminotransferase ( ALT) ≤3 × institutional upper limit of normal * Albumin≥3g/dL * Total bilirubin ≤3mg/dL * PT≤3 × institutional upper limit of normal or INR≤2.3 * Creatinine ≤1.5 × institutional upper limit of normal * Ability to understand and the willingness to sign a written informed consent document Exclusion Criteria: * Patients with other malignant tumors * History of other anti-cancer therapy, including surgery,radiation, ablation and so on * Pregnant or lactating women * Patients with Immunodeficiency disease * Several heart disease, for example: New York Heart Association (NYHA) class III/IV congestive heart failure，active coronary heart disease and severe arrhythmia * Uncontrolled hypertension * Ongoing or active infection (\>grade 2 based on National Cancer Institute-Common Terminology Criteria for Adverse Events (NCI-CTCAE) 4.0 edition) * Active tuberculosis * Chronic renal insufficiency * Other organ failure * History of organ transplantation * History of severe mental illness