Abstract
BACKGROUND: Pancreatic acinar cell carcinoma (PACC) and pancreatoblastoma (Pb) are rare exocrine pancreatic malignancies with liver-dominant metastatic patterns and poor prognosis. Limited treatment options exist beyond the extrapolated pancreatic ductal adenocarcinoma regimens. Yttrium-90 (Y-90) radioembolization has demonstrated efficacy in various hepatic malignancies but remains understudied in these rare pancreatic tumors. These cases illustrate the potential role of Y-90 radioembolization in achieving durable hepatic disease control in PACC and Pb patients. CASE SUMMARY: Case 1: A 62-year-old man with metastatic PACC underwent four Y-90 radioembolizations over 46 months, achieving partial responses after each treatment with sustained disease control exceeding one year without systemic therapy. Case 2: A 78-year-old woman with metastatic Pb following radical pancreaticoduodenectomy received four sequential Y-90 treatments targeting hepatic metastases, demonstrating partial responses to the treated metastases which established ongoing local disease control. Both patients tolerated multiple Y-90 sessions well with minimal complications. The treatments were successfully integrated with systemic therapies and provided meaningful symptom relief. These cases demonstrate the radiosensitivity of these rare malignancies and the feasibility of repeated Y-90 administrations over extended intervals in selected patients. CONCLUSION: Y-90 radioembolization achieves durable hepatic response in rare pancreatic exocrine malignancies with a favorable safety profile.