Selective Intra-Arterial Calcium Stimulation Venous Sampling Test for Preoperative Localization of Occult Neuroendocrine Tumors: Recall for an Old Technique

Abstract

Abstract Background Surgical resection is the curative treatment for neuroendocrine tumors (NETs). Noninvasive imaging is unreliable in localizing NETs measuring less than 2 cm. This study investigates the safety and efficacy of the selective intra-arterial calcium stimulation venous sampling test (SACST) for preoperative localization of functional NETs within the pancreas. Methods This retrospective analysis of the patients referred for localization of radiologically occult functional NETs from 2004 to 2019 was performed at a single institution. The technical success, diagnostic accuracy, and complications of the test were evaluated. Results Twenty-three patients underwent SACST. The SACST was technically successful in 100% of the patients. Lesions were successfully localized in 19 (83%) patients. Tumor blush was seen in one patient. The mean ± standard deviation of maximal dimension of the resected tumor was 2.0 ± 1.9 cm. Sensitivity, specificity, positive predictive value, and negative predictive value of the SACST for localization of all lesions were 1.0, 0.57, 0.84, and 1.0, as well as 1.0, 0.57, 0.80, and 1.0 for insulinomas, respectively. Conclusion SACST is a feasible, safe, well-tolerated, and effective procedure to preoperatively localize radiologically occult NETs within the pancreas.