Background  Recently, multidisciplinary comprehensive treatment including surgery, chemotherapy, radiotherapy, targeted therapy, and immunotherapy has made great progress and significantly improved the efficacy of treatment for a variety of tumors. However, the clinical efficacy of modern comprehensive treatment based on radical surgery in patients with pancreatic cancer is still unclear.

  Objective  To analyze the clinical practice and outcome of radiotherapy-based combination therapy in patients with pancreatic cancer after R0/R1 surgery, and explore the postoperative failure pattern and prognostic factors influencing these patients.

  Methods  Totally 95 patients with pancreatic cancer who received radiotherapy after R0/R1 surgery from January 2016 to December 2020 at the Department of Radiation Oncology in the First Medical Center of Chinese PLA General Hospital were collected. The clinical practice and outcome of radiotherapy-based combination therapy in patients with pancreatic cancer after R0/R1 surgery were analyzed, and the postoperative failure pattern and prognostic factors were explored.

  Results  The median age of the 95 patients was 57 years (31-75 years), and the male to female ratio was 59:36. There were 50, 35 and 10 patients in stage Ⅰ, Ⅱ and Ⅲ, respectively. Among these patients, 14 cases were treated with surgery + radiotherapy, and 81 cases were treated with surgery + radiotherapy + chemotherapy. According to the radiotherapy intervention, 11 cases (11.6%) were treated with postoperative adjuvant radiotherapy, 57 cases (60%) were treated with radiotherapy for local-regional recurrent lesions, and 27 cases (28.4%) were treated with radiotherapy for distant metastatic lesions. The incidence of localized recurrence, regional recurrence, and distant metastasis was 48.4% (46/95), 30.5% (29/95), and 49.5% (47/95), respectively. The median disease-free survival (mDFS) of patients with pancreatic cancer after R0/R1 surgery was 16.3 months, and the median overall survival (mOS) of patients receiving radiation-based comprehensive treatment after R0/R1 surgery and radiotherapy was 27.5 months and 9.9 months, respectively. The corresponding 1-year, 3-year, and 5-year survival rates were 93.6%, 30.2%, and 12.4%. Multivariate analysis demonstrated that gender, peripancreatic nerve invasion, tumor size, the interval between surgery and radiotherapy, and the number of total cycles of received chemotherapy were independent prognostic factors for these entities (all P<0.05).

  Conclusion  The radiotherapy-based comprehensive treatment can effectively improve the long-term survival of patients with pancreatic cancer after R0/R1 surgery.