Context: Selective internal radiation (SIR) therapy (SIRT) with yttrium 90 microspheres is increasingly used as an alternative therapeutic modality for patients with inoperable liver tumors. During administration of microspheres via the hepatic artery branches, some may on occasion be misdirected and be caught in the capillary bed of the duodenal and/or stomach.
Objective: To better characterize the histopathologic features of these complications.
Design: We report herein our experience with 3 patients who received SIR and developed gastroduodenal complications.
Results: SIR-microsphere-induced gastroduodenitis was diagnosed from 10 days to 5 months after treatment. In all 3 cases, purple particles measuring about 40 microm in diameter were observed. An array of changes ranging from mucosal ulceration to epithelial changes were seen. Fibrinopurulent exudate was admixed with granulation tissue and reactive stromal cells. Epithelial changes included apoptosis and mucin depletion. Glandular cystic dilatation and epithelial flattening were also common as well as foveolar hyperplasia, suggestive of reparative changes in one case. Capillary ectasia and prominent plump endothelial cells were also present.
Conclusion: The spectrum of the alterations is consistent with radiotherapy-induced changes. Given the recent approval by the US Food and Drug Administration for the use of SIRT, it is anticipated that more patients will be treated with this modality. Pathologists should become aware of the adverse effects associated with its use.