Stereotactic Body Radiation Therapy Followed by NALIRIFOX vs NALIRIFOX for Borderline Resectable Pancreatic Cancer

Inclusion Criteria:

* Age: ≥18 years old.
* Histologically or cytologically proven pancreatic ductal adenocarcinoma.
* Multidisciplinary assessment as borderline resectable disease.
* At least one measurable lesion (according to RECIST v1.1).
* No prior antitumor therapy for pancreatic cancer.
* Eastern Cooperative Oncology Group (ECOG) performance status of 0 \~ 1.
* The expected survival time ≥3 months.
* Adequate bone marrow function as evidenced by: 1) Absolute neutrophil count (ANC) ≥1.5×10\^9/L, 2) Platelet count ≥100×10\^9/L, 3) Hemoglobin (Hb) ≥90 g/L, 4) White blood cell (WBC) ≥3.0×10\^9/L.
* Adequate hepatic function as evidenced by: 1) Serum total bilirubin ≤1.5 × upper limit of normal (ULN), 2) Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) ≤2.5 × ULN
* Adequate renal function as evidenced by serum creatinine (Cr)≤1.5 × ULN or creatinine clearance ≥60 mL/min.
* Agree and be able to comply with the plan during the study period. Provide written informed consent before entering the study screening.

Exclusion Criteria:

* Any other malignancy within 5 years, with the exception of cured in-situ carcinoma or basal cell carcinoma etc.
* Patients with distant metastases and/or cannot complete resection.
* Active, uncontrolled bacterial, viral, or fungal infections that require systemic treatment.
* Active HIV, HBV, HCV infection.
* Combined with uncontrollable systemic diseases.
* Presence of severe gastrointestinal disease (including active bleeding, \> grade 1 obstruction \[CTCAE v5.0\], or \> grade 1 diarrhea \[CTCAE v5.0\]).
* History of allergy or hypersensitivity to drug or any of their excipients.
* Patients who have chemotherapy and surgery contraindications.
* Documented serum albumin ≤3 g/dL
* Use of strong inhibitors or inducers of CYP3A, CYP2C8 and UGT1A1 within 14 days before the first administration.
* Pregnant or breastfeeding women, or subjects of childbearing age who refuse contraception.
* Participated in other trial within 30 days before the first administration.
* Patients who are not suitable to participate in this trial for any reason judged by the investigator.