Preoperative Localization of a Gastrin-Secreting Tumour by Total Body Imaging with111Indium-Labelled Pentatreotide

A 41-year-old female presented with persistent diarrhea, and was diagnosed with Zollinger-Ellison syndrome when her gastrin level was greater than 3000 ng/L. All modalities for preoperative localization of her gastrinoma were unsuccessful, including transabdominal and endoscopic ultrasound, computed tomography, pancreatic angiogram, selective transhepatic portal venous sampling and magnetic resonance imaging. The gastrin-secreting tumour was visualized using the somatostatin analogue pentatreotide labelled with 111Indium, combined with gamma camera imaging. A successful resection of the tumour resulted in the normalization of serum gastrin levels 3.5 years after presentation. A discussion of the merits and sensitivities of these tests for preoperative localization of gastrin-secreting tumours will be presented