Stent Migration and Fistula Formation Following Stereotactic Body Radiation Therapy for Pancreatic Cancer

Abstract Locally advanced pancreatic cancer (LAPC) is associated with a poor prognosis, with rates of eventual surgical resection after neoadjuvant therapies ranging from 10% to 30%. When such tumors are in the pancreatic head, obstructive jaundice is often the presenting symptom, necessitating endoscopic stent placement. Interval stent migration is possible at any time due to several factors, including the mechanical properties of self-expandable metal stents (SEMS), complete sphincterotomy, tumor regrowth, and improved tumor response from chemotherapy and radiation. A 75-year-old woman presented with pancreatic head/neck LAPC who received chemotherapy and stereotactic MR-guided adaptive radiation therapy (SMART) with ablative dose on an MRI linear accelerator. Post-treatment imaging at 6 months incidentally revealed that the previously placed biliary SEMS was dislodged into the duodenum. Endoscopic removal was not performed due to a 10-mm fistulous opening proximal to the major papilla in direct communication with the stent. This case reports stent migration and fistula formation postablative SMART.