A 55-year-old man with refractory peptic ulcer disease is found to have Zollinger-Ellison syndrome (ZES). Sestamibi scan and CT fail to localize the gastrinoma. What is the best next localizing investigation?
- A 68Ga-DOTATATE PET-CT (somatostatin receptor PET) ✓
- B Selective arterial secretin injection (SASI) with hepatic venous sampling
- C Endoscopic ultrasound (EUS) of the duodenum and pancreatic head
- D MRI abdomen with gadolinium enhancement
Explanation
68Ga-DOTATATE PET-CT (somatostatin receptor scintigraphy using PET technology) has sensitivity exceeding 90% for gastrinoma localization and has largely replaced conventional octreotide scintigraphy (Octreoscan) as the gold standard for neuroendocrine tumor localization in suspected ZES. It is superior to CT, MRI, and EUS for detecting small duodenal wall gastrinomas and distant metastases simultaneously. SASI/secretin test is a functional localization technique for small tumors when anatomical imaging fails, but is invasive. EUS has 70–80% sensitivity but misses extra-pancreatic duodenal tumors. 68Ga-DOTATATE PET should be the next step when cross-sectional imaging and nuclear medicine are negative.
Reference: Bailey & Love's Short Practice of Surgery, 27th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.