Efficacy of Stereotactic Body Radiotherapy (SBRT) Combined With Maintenance Therapy Compared to Maintenance Therapy Alone in Advanced Pancreatic Cancer

Inclusion Criteria:

• Age 18 to 70 years old.
• Histologically or cytologically confirmed diagnosis of pancreatic - adenocarcinoma.
• No prior radiation therapy for pancreatic cancer.
• At least one measurable lesion of the primary pancreatic tumor as per RECIST 1.1 criteria, eligible for SBRT.
• Completion of first-line chemotherapy with stable disease (SD) or partial response (PR) after ≥4 months of treatment.
• ECOG performance status of 0-2.
• Expected survival of ≥3 months.
• Adequate organ function within 14 days prior to enrollment:
• Hemoglobin (Hb) ≥ 90 g/L
• Absolute neutrophil count (ANC) ≥ 1.5×10⁹/L
• Platelets (PLT) ≥ 75×10⁹/L
• Total bilirubin ≤ 1.5× ULN or direct bilirubin ≤ ULN
• ALT/AST ≤ 2.5× ULN
• ALP ≤ 2.5× ULN
• Serum creatinine ≤ 1.5× ULN or calculated creatinine clearance ≥ 40 mL/min
• Urine protein < 2+ (if ≥2+ on dipstick, 24-hour urine protein must be < 2g)
• No use of systemic corticosteroids in the last 7 days prior to enrollment (physiological corticosteroid replacement is allowed).
• Women of childbearing potential and men must use effective contraception during the study and for 12 months following treatment completion.
• Voluntary participation with signed informed consent.
• Ability to comply with the study schedule.

Exclusion Criteria:

• Currently participating in any interventional clinical trial or having received other investigational drugs or devices within 4 weeks prior to enrollment.
• Peritoneal metastasis.
• Known active central nervous system (CNS) metastasis and/or carcinomatous meningitis.
• Receiving systemic corticosteroid treatment within 7 days prior to enrollment (except for physiological doses).
• Active, untreated hepatitis B (HBsAg positive and detectable HBV-DNA) or active hepatitis C infection (HCV antibody positive and detectable HCV RNA).
• Pregnant or breastfeeding women.
• Any severe or uncontrolled systemic disease, including:
• QTc interval ≥ 480 ms
• Unstable angina
• NYHA class III-IV congestive heart failure
• Arterial thromboembolism (MI, unstable angina, stroke, TIA) within 6 months prior to enrollment
• Uncontrolled hypertension (systolic BP ≥ 150 mmHg, diastolic BP ≥ 90 mmHg)
• Active pulmonary tuberculosis, severe infections, or other uncontrolled diseases
• Active gastrointestinal perforation, fistula, or bowel obstruction.
• Inadequately controlled diabetes (fasting blood glucose > 10 mmol/L).
• History of mental illness preventing compliance with treatment.
• Active bleeding or significant coagulation abnormalities within the last 30 days.
• Previous gastrointestinal perforation or other serious gastrointestinal conditions in the past 6 months.
• Participation in other trials that may interfere with this study.