Regorafenib-Associated Acute Pancreatitis Diagnosed on 18F-FDG PET/CT.

A 23-year-old man with metastatic osteosarcoma, with disease progression on conventional chemotherapy, was treated with regorafenib, a multikinase inhibitor. After treatment for 6 months with regorafenib, 18F-FDG PET/CT scan demonstrated FDG uptake in a necrotic space-occupying lesion involving tail of pancreas. After imaging, patient described symptoms of epigastric pain with elevated serum amylase and lipase levels, confirming diagnosis of regorafenib-induced pancreatitis, because patient had no other causative factors of pancreatitis. Physicians should be aware of rare and possibly clinically silent adverse effects of tyrosine kinase inhibitors, like acute pancreatitis, and recognize the 18F-FDG PET/CT findings to guide appropriate clinical management.