Long-Term Multifocal Pulmonary Fibrosis Associated with Y-90 Embolization: A Case Report and Literature Review

Radioembolization with Yttrium-90 (Y-90) beads is used to shrink liver tumors and reduce the tumor burden. However, a side effect of this treatment can be the shunting of Y-90 beads to the pulmonary circulation, leading to short-term radiation pneumonitis. While the short-term effects of hepatopulmonary shunting are well-defined, long-term complications have not been explored in the literature. We discuss the finding of multifocal interstitial pulmonary fibrosis in a patient treated with Y-90 for hepatocellular carcinoma. The reticular opacities were identified on chest CT scans seven months after the procedure and continued to consolidate up to 75 months post-radioembolization. Pathology confirmed multifocal fibrosis associated with Y-90 beads. This happened despite a low LSF and in the absence of clinical evidence of post-treatment radiation pneumonitis or chronic interstitial lung disease. This case report identifies radiation fibrosis as a differential diagnostic consideration when working up post-radioembolization patients with unexplained reticular opacities on lung imaging.