The objective is to evaluate the efficacy and safety of carbon ion radiotherapy (CIRT) combined with nituzumab and gemcitabine in the treatment of locally advanced and metastatic pancreatic cancer.

The objective is a single-center, single-arm, prospective Phase II clinical trial was conducted to evaluate the safety and efficacy of this regimen.

The primary criteria for inclusion were 18 to 80 years of age, histologically or cytologically confirmed pancreatic ductal adenocarcinoma, and clinician assessment as inoperable or patient rejection of manual surgery. All eligible patients will receive CIRT in combination with gemcitabine and nituzumab. The primary endpoint of the study was progression-free survival (PFS). All patients included in the study were followed for survival for at least 12 months. A safe and effective segmentation dose for pancreatic cancer suitable for our facility and RBE model was obtained. The comprehensive treatment of carbon ion radiation therapy, targeted therapy and chemotherapy is effective of refractory tumors, radiation-resistant tumors, and complex tumors. Using the physical dosimetry and biological advantages of heavy ions, we can improve the tumor control rate and reduce the occurrence of surrounding normal tissue damage, and provide new treatment suggestions for locally advanced and metastatic pancreatic cancer.

Inclusion Criteria:

1. Age ≥18 years and ≤80 years;
2. Indications: patients with locally advanced or metastatic pancreatic adenocarcinoma confirmed by histopathology or cytology (stage III - IV).
3. At least one measurable lesion was present according to RECIST version 1.1 evaluation criteria.
4. Suitable for one cycle of gemcitabine combined with nituzumab.
5. No history of other malignant tumors (except cured skin cancer and stage 0 cervical cancer);
6. Liver function, kidney function and bone marrow function were basically normal (ALT and AST < 1.5 times of high normal value (ULN), bilirubin < 1.5×ULN; Adult endogenous creatinine clearance rate of 60ml/min or serum creatinine SCR≤140μmoI/L, BUN≤6.8mmol/L; Hemoglobin level >9 g/dL; White blood cell count ≥3.0*109/L; Platelet count ≥100*109/L;)
7. Good physical condition, i.e. ECOG (Eastern United States Oncology Collaboration Group) 0~2; There were no complications such as severe pulmonary hypertension, cardiovascular disease, peripheral vascular disease, and severe chronic heart disease that may affect radiotherapy. Cardiac function grade 1. (According to the New York College of Cardiology Cardiac Function Scale (NYHA)
8. Adequate functions of major organs;
9. Predicted survival (after treatment) ≥3 months;
10. Informed consent has been signed by the patient or his legal representative before radiotherapy.

Exclusion Criteria:

1. Patients who have received monoclonal antibodies, EGFR-TKI therapy, anti-angiogenic drugs, and immunosuppressants within six months.
2. Patients with uncontrolled, cancerous pleural effusion requiring frequent drainage, pericardial effusion, or ascites (allowing for cytological confirmation of effusion), gastrointestinal bleeding, or those identified by the investigator as having a high blood risk within 14 days prior to admission.
3. Participated in other interventional clinical trials within 30 days prior to screening.
4. The dose limit for organs at risk cannot reach the preset safe dose limit.
5. Being on chronic steroid hormone therapy for more than 6 months (e.g., prednisone dose > 10 mg/ day or equivalent).
6. People who are allergic to the drugs or their ingredients used in this program.
7. Pregnancy (confirmed by serum or urine β-HCG test) or lactation
8. Persons with AIDS, including those who have received antiretroviral therapy; Active stage of syphilis;
9. Accompanied by serious comorbiditions, including uncontrolled systemic or co-existing diseases (pulmonary insufficiency, cardiovascular, pulmonary, liver, kidney, diabetes, etc.), drug or alcohol abuse, dependence, addiction, and/or mental illness that prevent the successful implementation of the trial protocol;
10. Patients with poor compliance, including those who may not be able to complete the treatment plan or receive prescribed follow-up and examination;
11. Patients had other malignant neoplasms (except cured skin cancer and stage 0 cervical cancer);
12. There are contraindications to radiotherapy;
13. having no or limited capacity for civil conduct;
14. Any medical history that, in the investigator's judgment, might interfere with the trial results or increase the patient's risk;
15. Any condition in which the physician considers that participation in the trial is not appropriate, the physician determines that the patient will not benefit from carbon ion radiotherapy, or that there are other co-existing conditions or other factors that may affect carbon ion therapy.
16. Inability to understand the purpose of treatment or unwillingness/inability to sign treatment consent.