Intraoperative radiation therapy during pancreatectomy for borderline and locally advanced pancreatic cancer: A propensity-matched analysis.

Abstract

Borderline resectable and locally advanced pancreatic ductal adenocarcinoma remains associated with high local recurrence despite modern neoadjuvant therapy and surgery. Intraoperative radiation therapy enables targeted radiation delivery to the tumor bed while minimizing exposure to surrounding structures, yet its oncologic benefit in pancreatic ductal adenocarcinoma remains unclear. This study evaluated whether intraoperative radiation therapy improves survival and recurrence outcomes in borderline resectable/locally advanced pancreatic ductal adenocarcinoma patients undergoing pancreatectomy after neoadjuvant therapy. Retrospective cohort study (Jan 2010-Dec 2024) of borderline resectable/locally advanced pancreatic ductal adenocarcinoma patients undergoing pancreatectomy with or without intraoperative radiation therapy at a single high-volume center. Following institutional adoption of intraoperative radiation therapy in 2021, propensity score matching (1:1) was adjusted for demographics, tumor size, therapies, and comorbidities. The primary endpoint was recurrence-free survival, evaluated as local recurrence-free survival and distant recurrence-free survival. Secondary endpoints included overall survival and major complications. After matching, 100 patients (50 intraoperative radiation therapy, 50 controls) with a median follow-up of 21.2 months were analyzed. Groups were balanced for tumor biology and resection quality (88% vs 90% R0). Intraoperative radiation therapy was associated with improved local recurrence-free survival at 24 months (79% vs 53%; P = .049) and reduced local recurrence risk (hazard ratio, 0.46; 95% confidence interval, 0.22-0.98; P = .043). Overall survival at 24 months favored intraoperative radiation therapy (58% vs 43%; log-rank P = .058), with an independent association on multivariable analysis (hazard ratio, 0.57; P = .038). Distant recurrence-free survival did not differ. Major complications were comparable (10% vs 21%). Intraoperative radiation therapy was associated with improved local control in borderline resectable/locally advanced pancreatic ductal adenocarcinoma without added morbidity, warranting prospective validation.