External beam radiotherapy for angiographically diagnosed arteriovenous malformation involving the entire pancreas.

Ultrasonography of a 66-year-old man with abdominal discomfort detected an abnormality of the pancreas. Multiphase contrast-enhanced computed tomography (CT) and angiography revealed arteriovenous malformation (AVM) involving the entire pancreas. The large number of dilated and tortuous feeding arteries contraindicated surgical resection or transcatheter embolization. Hemorrhage into the main pancreatic duct occurred 1 month after diagnosis. The patient underwent external radiotherapy with a total dose of 44 Gy following a conventional fractionation schedule of 2 Gy daily for 22 days administered 5 days per week. Contrast-enhanced CT after treatment confirmed disappearance of feeding vessels and nidi with no complication. Evidence of recurrence was not detected on contrast-enhanced CT 6 months after irradiation.