Context. The reliable localization of insulinoma is critical for the successful surgical treatment.Objective. This study compared the accuracy of 68 Gallium (Ga)-DOTATATE PET/CT to anatomic imaging modalities, selective arterial secretagogue injection (SASI), and intraoperative ultrasound (IOUS) and palpation for localizing insulinoma in patients who were biochemically cured. Design, Setting, and Patients. We conducted a retrospective analysis of 31 patients who had an insulinoma confirmed on histology and were biochemically cured. The results of CT, MRI, transabdominal US, IOUS, 68 Ga-DOTATATE PET/CT, SASI, and operative findings were analyzed. Intervention, Main Outcome Measures, Results: The insulinomas were correctly localized in 17 out of 31 (55%) of patients by CT, in 17 out of 28 (61%) by MRI, in 6 out of 28 (21%) by US, and in 9 out of 10 (90%) by 68 Ga-DOTATATE. IOUS was performed in 31 patients, and 29 of them had an insulinoma successfully localized (93.5%). Thirty patients underwent SASI, and the insulinoma was regionalized in 28 out of 30 patients (93%). In 19 out of 23 patients (83%), manual palpation identified insulinoma. In patients who had all four noninvasive imaging studies, CT was concordant with 68 Ga-DOTATATE in 6 out of 9 patients (67%); MRI in 8 out of 9 (78%); US in 0 out of 9; and in 1 out of 9 patients (11%) the lesion was only seen by 68 Ga-DOTATATE.
Conclusions:68 Ga-DOTATATE PET/CT identifies most insulinomas and may be considered as an adjunct imaging study when all imaging studies are negative and when a minimally invasive surgical approach is planned.PRECIS: We studied 68Ga-DOTATATE PET/CT imaging in patients with insulinoma and found it identifies most tumors and should be considered as an adjunct imaging study.