CLINICAL STUDY Radioembolization with Yttrium-90 Microspheres for the Treatment of Liver Metastases of Pancreatic Adenocarcinoma: A Multicenter Analysis Alexander Y. Kim, MD, Shelby Frantz, MD, Jayson Brower, MD, and Nabeel Akhter, MBBS ABSTRACT Purpose: To retrospectively assess the efficacy and safety of radioembolization with yttrium-90 ( 90 Y) resin microspheres as a second- line option in patients with liver metastases from pancreatic adenocarcinoma. Materials and Methods: Thirty-three patients with metastatic pancreatic adenocarcinoma that progressed despite systemic chemotherapy and other treatments directed at primary tumors and metastases were treated with 90 Y radioembolization at 1 of 3 in- stitutions from 2011 through 2017. Data from laboratory and imaging studies at 2, 4, 8, and 12 weeks after treatment were analyzed. Tumor response was assessed with Response Evaluation Criteria In Solid Tumors version 1.1 and adverse events with Common Ter- minology Criteria for Adverse Events version 4.0. Results: Imaging results showed partial response in 8 patients (42%), stable disease in 7 (37%), and progressive disease in 4 (21%). Median overall survival times after radioembolization and diagnosis of the primary tumor were 8.1 (95% CI, 4.8–12.5) and 20.8 (95% CI, 14.2–29.0) months, respectively. Radioembolization did not produce major hepatic toxicity, and changes in liver enzyme levels were rarely grade  3 during the 12-week follow-up. The exceptions were 3 patients with grade 3 increased alkaline phosphatase (week 2) and bilirubin levels (week 4), increased bilirubin level (week 12), and decreased albumin level (week 12), respectively. Most reported complications were grade  2, with 2 patients showing short-term radioembolization-related grade 3 abdominal distention, abdominal pain, fatigue, or ascites. Conclusions: Yttrium-90 radioembolization provided a meaningful survival benefit in patients with liver metastases from pancreatic adenocarcinoma that progressed despite previous therapies. Adverse events and liver toxicity were tolerable and only occasionally severe (grade  3). ABBREVIATIONS ALP ¼ alkaline phosphatase, CI ¼ confidence interval, CR ¼ complete response, CTCAE ¼ Common Terminology Criteria for Adverse Events, 5-FU ¼ 5-fluorouracil, HR ¼ hazard ratio, LV ¼ leucovorin, nal-IRI ¼ nanoliposomal irinotecan, OS ¼ overall sur- vival, PD ¼ progressive disease, PR ¼ partial response, RECIST ¼ Response Evaluation Criteria In Solid Tumors, REILD ¼ radio- embolization-induced liver disease, SD ¼ stable disease, 90 Y ¼ yttrium-90 For patients with unresectable metastatic pancreatic cancer, chemotherapy represents the most frequent treatment. Rec- ommended first-line therapies (1–5) have considerably improved outcomes. However, 1-year survival rates remain lower than 50% even in patients not previously treated for metastatic disease (1,5). From the Division of Vascular and Interventional Radiology (A.Y.K., S.F.), MedStar Georgetown University Hospital, 3800 Reservoir Rd. NW, Washing- ton, DC 20007-2113; Department of Radiology (J.B.), Inland Imaging, Provi- dence Sacred Heart Medical Center, Spokane, Washington; and Division of Vascular and Interventional Radiology (N.A.), University of Maryland Medical System, Baltimore, Maryland. Received April 11, 2018; final revision received September 7, 2018; accepted September 16, 2018. Address correspon- dence to A.Y.K.; E-mail: alexander.y.kim@gunet.georgetown.edu From the SIR 2018 Annual Meeting. A.Y.K. is a paid consultant for Sirtex Medical (North Sydney, Australia) and SureFire Medical (Westminster, Colorado), receives research support from Surefire Medical, owns stock and maintains ownership interest in Pfizer (New York, New York) and Surefire Medical, and has received honoraria from AngioDynamics (Latham, New York) and Bayer (Leverkusen, Germany). J.B. is a paid consultant for Sirtex Medical, BTG (West Conshohocken, Pennsylvania), and Merit Medical (South Jordan, Utah). N.A. receives honoraria from Angio- Dynamics. The other authors have not identified a conflict of interest. Tables E1–E4 can be found by accessing the online version of this article on www.jvir.org and clicking on the Supplemental Material tab. © SIR, 2018 J Vasc Interv Radiol 2019; 30:298–304 https://doi.org/10.1016/j.jvir.2018.09.020