Patient 17.90 Y radioembolization of a recurrent intra-hepatic cholangiocarcinoma. (a) Pre-radioembolization coeliac axis ‘C’ digital subtraction angiography (DSA) shows the common hepatic artery bifurcating into the right hepatic and gastroduodenal arteries ‘GDA’, later branching into the right gastroepiploic artery ‘RGE’. DSA at the conclusion of 90Y radioembolization demonstrated significant vascular stasis and reflux of contrast into the gastroduodenal and right gastroepiploic arteries (images not shown). (b) Coronal view of post-radioembolization 90Y PET/CT and its (c) MIP demonstrates in high resolution, non-target activity along the gastric greater curve ‘G’, antrum ‘A’ and proximal duodenum ‘D’. (d) MIP of 90Y bremsstrahlung SPECT shows concordant non-target activity, but of lower intensity and resolution. By quantification 90Y PET activity, detailed in Part 2 , the non-target mean absorbed doses to the gastric greater curve, gastric outlet, and proximal duodenum were approximately 49, 65, and 53 Gy, respectively. Within weeks, the patient developed persistent epigastric pain. (e) Gastroscopy at 3.3 months revealed extensive inflammation along the stomach and proximal duodenum. A Forrest III ulcer was present in the pylorus (large arrow). The ulcer edge (small arrows) was inflamed and indurated. (f) Photomicrograph (H&E stain; ×200) of the gastric biopsy showed edema, congestion, and diffuse lymphoplasmacytic, eosinophilic, and neutrophilic infiltrates. A purple-staining resin microsphere (arrow) surrounded by a halo was seen in the lamina propria. The surrounding gastric glands show flattening of the epithelium, dilatation, and reactive atypia, consistent with severe cellular injury.