Which is the best investigation for metastatic gastrinoma?: (A) Selective aerial secretin injection, (B) Octreoscan, (C) BAO/MAO ratio, (D) Ultrasound
Answer is B. In case of gastrinoma showing metastasis the diagnostic sensitivity of octreoscan is 80-100%. In contrast in primary gastrinoma, Endoscopic ultrasound shows a sensitivity of 80-100% versus octreoscan which shows a sensitivity of 67-86%.