Abstract
OBJECTIVE: This study aims to evaluate the efficacy and safety of stereotactic body radiation therapy (SBRT) using Cyber Knife (CK) in the treatment of patients with recurrent pancreatic cancer after surgery, and analyze its survival-related factors. METHODS: The primary endpoint was freedom from local progression (FFLP) and local control (LC) rate after CK. The secondary endpoints were overall survival (OS), progression-free survival (PFS), symptom relief and toxicities. Receiver operating characteristic (ROC) curves were used to determine the optimal cut-off values of inflammatory composite indicators NLR, PLR, SII and PNI. The prognostic factors that affected these patients were analyzed by univariate and multivariate analysis, respectively. RESULTS: A total of 27 patients were enrolled. Median local recurrence disease free interval（DFI）was 11.3 (1.3-30.6) months, LC was 81.5% and 37.0% at 6 and 12 months, respectively. Median PFS was 7.1 (1.3-27.1) months. Median OS was 11.3 (1.3-30.6) months. Symptom alleviation was observed in 16 of 17 patients (94.1%) within 2 weeks after CK. Subsequent chemotherapy, CA199≥50% decrease after CK were independent prognostic factors for OS (all P <0.05). CONCLUSION: SBRT is a safe and effective treatment approach for recurrent pancreatic adenocarcinoma. Encouraging local control rate, low toxicity, and effective symptom relief suggests the vital role of CK in the treatment of these patients. This clinical application needs to be further studied in the combination of CK and multimodal therapy.