Microvascular injury in persistent gastric ulcers after yttrium-90 microsphere radioembolization for liver malignancies

Summary Yttrium-90 microsphere radioembolization (⁹⁰Y MRE) is a therapy for liver malignancies by permanently implanting ⁹⁰Y-containing microspheres into tumors via hepatic artery. The etiology of persistent gastric ulcerations in patients presenting months after treatment remains unclear. Three patients who presented with gastric ulceration 4 to 13 months after ⁹⁰Y MRE were examined by esophagogastroduodenoscopy and biopsies. Pathological examinations showed multiple ⁹⁰Y microspheres scattered within the lamina propria and submucosa. Most of the microspheres were distributed in a linear fashion, consistent with an intravascular location; however, the vascular lumen and endothelial cells were not present. The microspheres were surrounded by fibrotic tissue infiltrated by chronic inflammatory cells and rare neutrophils. Epithelial granulation without pititis and miniaturized glands with intervening fibrosis were noted, compatible with chronic ischemic changes. These findings suggest that the persistent gastric ulceration is a result of localized ischemic injury in response to ⁹⁰Y MRE-induced vascular damage.