Successful Palliative Radiotherapy for Tumor-Induced Acute Pancreatitis: Two Case Reports

Acute pancreatitis caused by pancreatic involvement of malignant tumors has been reported as "tumor-induced acute pancreatitis (TIAP)" or "metastasis-induced acute pancreatitis (MIAP)." Radiotherapy is widely used to palliate symptoms in various malignancies; however, its role in TIAP has not been systematically reported. We report two cases in which palliative radiotherapy was effective for TIAP. The first case was a 59-year-old woman with multiple myeloma who had received chemotherapy and two autologous stem cell transplantations over 8 years, followed by disease progression. She developed elevated pancreatic enzyme levels and epigastric tenderness. Computed tomography (CT) revealed an extramedullary lesion in the pancreatic head and enlargement of the pancreatic tail, and magnetic resonance cholangiopancreatography (MRCP) showed mild dilatation of the main pancreatic duct. After aggressive intravenous hydration, palliative radiotherapy of 8 Gy in 2 fractions was delivered to the pancreas. Pancreatic enzyme levels decreased and epigastric pain improved, with no recurrence. The second case was a 61-year-old man with pancreatic neuroendocrine carcinoma and involvement of the glottis and cervical lymph nodes. Approximately 9 months after initiation of chemotherapy, he developed elevated pancreatic enzyme levels and upper abdominal pain. Contrast-enhanced CT demonstrated enlargement of multiple intrapancreatic nodules. Palliative radiotherapy of 20 Gy in 5 fractions was delivered to the pancreas. Upper abdominal pain improved after irradiation, and pancreatic enzyme levels decreased during treatment. In both cases, no apparent acute adverse events related to radiotherapy were observed. In conclusion, radiotherapy for TIAP may contribute to pain relief, reduction in pancreatic enzyme levels, and tumor shrinkage. In similar cases, radiotherapy may play an important role in improving quality of life and enabling continuation of systemic therapy and should be considered a treatment option.