PROSPECTIVE-STUDY OF PROVOCATIVE ANGIOGRAMS TO LOCALIZE FUNCTIONAL ISLET-CELL TUMORS OF THE PANCREAS

Background. Controversy exists concerning the use of preoperative imag ing studies in patients with islet cell tumors. Since 1993 we have eva luated the use of provocative angiography in patients with insulinoma or Zollinger-Ellison syndrome (ZES). Methods, Twelve patients with a w orking diagnosis of insulinoma (n = 4) or ZES (n = 8) were studied. Of the eight patients with ZES, four were Known to have multiple endocri ne neoplasia type 1. All patients underwent conventional imaging studi es followed by provocative angiography. Angiograms were graded based o n the ability to detect tumor and regionalize it within the pancreas. Results. Of the three patients with a working diagnosis of ZES but equ ivocal results of biochemical studies, none had arteriographic imaging of an islet cell tumor or a positive provocative study result (true n egative result). Of the nine patients with documented islet cell tumor , seven (78%) underwent arteriographic imaging of the tumor and eight (89%) had correct regional localization by provocative angiography. Se nsitivity and specificity for imaging were 78% and 100%, respectively, and for regional localization 89% and 100%, respectively. Conclusions . Provocative angiography is the localization study of choice for both gastrinoma and insulinoma. Having few false-negative results, it can be used to corroborate the diagnosis and having few false-positive res ults, it detects tumor and biochemically confirms localization in near ly every patient.