Low-dose Selective Arterial Calcium Stimulation Test for Localizing Insulinoma: A Single-center Experience of Five Consecutive Cases

The selective arterial calcium stimulation test (SACST) is one of the most useful localization tests for insulinoma but can cause false-positive and/or unexpected multi arterial positive results that hamper clinical decisions. There are also several adverse effects, such as nausea and hypoglycemia, at the conventional dose (0.025 mEq/kg) of calcium injection. We herein report five consecutive insulinoma cases in which low-dose (0.005-0.007 mEq/kg) calcium injection for SACST led to successful insulinoma localization. No adverse effects of SACST were observed. In conclusion, a low-dose SACST can be a favorable option as an insulinoma localization test in terms of accuracy and safety.