Clinical Study of Carbon Ion Radiotherapy for Pancreatic Cancer.

Inclusion Criteria:

1. Age ≥18 years and ≤80 years;

2. Indications: patients with locally advanced or metastatic pancreatic adenocarcinomaconfirmed by histopathology or cytology (stage III - IV).

3. At least one measurable lesion was present according to RECIST version 1.1evaluation 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 cervicalcancer);

6. Liver function, kidney function and bone marrow function were basically normal (ALTand AST < 1.5 times of high normal value (ULN), bilirubin < 1.5×ULN; Adultendogenous 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 ≥3.0109/L; Plateletcount ≥100109/L;)

7. Good physical condition, i.e. ECOG (Eastern United States Oncology CollaborationGroup) 0~2; There were no complications such as severe pulmonary hypertension,cardiovascular disease, peripheral vascular disease, and severe chronic heartdisease that may affect radiotherapy. Cardiac function grade 1. (According to theNew 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 beforeradiotherapy.

Exclusion Criteria:

1. Patients who have received monoclonal antibodies, EGFR-TKI therapy, anti-angiogenicdrugs, and immunosuppressants within six months.

2. Patients with uncontrolled, cancerous pleural effusion requiring frequent drainage,pericardial effusion, or ascites (allowing for cytological confirmation ofeffusion), gastrointestinal bleeding, or those identified by the investigator ashaving a high blood risk within 14 days prior to admission.

3. Participated in other interventional clinical trials within 30 days prior toscreening.

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., prednisonedose > 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; Activestage of syphilis;

9. Accompanied by serious comorbiditions, including uncontrolled systemic orco-existing diseases (pulmonary insufficiency, cardiovascular, pulmonary, liver,kidney, diabetes, etc.), drug or alcohol abuse, dependence, addiction, and/or mentalillness that prevent the successful implementation of the trial protocol;

10. Patients with poor compliance, including those who may not be able to complete thetreatment plan or receive prescribed follow-up and examination;

11. Patients had other malignant neoplasms (except cured skin cancer and stage 0cervical 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 thetrial results or increase the patient's risk;

15. Any condition in which the physician considers that participation in the trial isnot appropriate, the physician determines that the patient will not benefit fromcarbon ion radiotherapy, or that there are other co-existing conditions or otherfactors that may affect carbon ion therapy.

16. Inability to understand the purpose of treatment or unwillingness/inability to signtreatment consent.