Successful control of intractable hypoglycemia using radiopharmaceutical therapy with strontium-89 in a case with malignant insulinoma and bone metastases

This report describes the case of a 57-year-old woman with liver and bone metastases from malignant insulinoma, who was afflicted with severe hypoglycemia. Treatment of the liver metastases using octreotide, diazoxide and transarterial embolization failed to raise her blood glucose level and she required constant glucose infusion (about 1000 kcal/day) and oral feeding (about 2200 kcal/day) to avoid a hypoglycemic attack. Subsequently, 110 MBq (2.0 MBq/kg) of strontium-89 were administered by intravenous injection. Three weeks after the strontium-89 injection, we could reduce the dose of constant glucose infusion while maintaining a euglycemic status. Six weeks after the injection, the constant glucose infusion was discontinued. Although strontium-89 therapy is indicated for patients with multiple painful bone metastases, it was also useful as a means of inhibiting tumor activity and controlling hypoglycemia in this case. To our knowledge, this is the first report to provide evidence that strontium-89 can be useful in controlling intractable hypoglycemia in patients with malignant insulinoma with bone metastases.