Localization of gastrinomas by selective intra-arterial calcium injection.
BACKGROUND
Preoperative localisation is important for successful surgical treatment of gastrinomas. However, a satisfactory method that achieves this has not been defined, and at present somatostatin receptor scintigraphy and selective intra-arterial stimulation testing with secretin have the greatest sensitivities. As secretin is now difficult to obtain, we decided to explore the use of calcium gluconate as a secretagogue. High extracellular calcium concentrations cause degranulation of neuroendocrine cells and subsequent release of hormone.


METHODS
Two patients with biochemically proven gastrinomas were investigated pre-operatively. Under angiographic control calcium gluconate was injected into the arteries supplying the pancreas and duodenum, gastrin levels were then determined in hepatic vein samples obtained before and 30, 60, 90, 120 and 180 seconds after each injection. One of the patients had also previously undergone selective intra-arterial stimulation testing with secretin.


RESULTS
Calcium gluconate produced sharp peaks of gastrin which unequivocally localised the tumour to a specific vascular territory in each case. Furthermore, surgery confirmed the localisations of the gastrinomas. Calcium injection, unlike secretin, into vascular territories without gastrinomas caused no rise in gastrin, thereby demonstrating calcium's greater specificity.


CONCLUSIONS
Calcium gluconate is a highly sensitive and specific alternative secretagogue to secretin for localisation of pancreatic and duodenal gastrinomas. Furthermore calcium gluconate was found to demonstrate the territory of the tumour more accurately than secretin.
Turner
J J O
JJ
Departments of Endocrinology and Imaging, Imperial College School of Medicine, Hammersmith Hospital, London.
Wren
A M
AM
Jackson
J E
JE
Thakker
R V
RV
Meeran
K
K
D000328:Adult; D000792:Angiography; D002125:Calcium Gluconate; D004379:Duodenal Neoplasms / Q000175:diagnosis / Q000378:metabolism*; D004386:Duodenum / Q000098:blood supply / Q000000981:diagnostic imaging; D005260:Female; D015408:Gastrinoma / Q000175:diagnosis / Q000378:metabolism*; D005755:Gastrins / Q000097:blood / Q000378:metabolism*; D006503:Hepatic Veins; D006801:Humans; D007269:Injections, Intra-Arterial; D008297:Male; D008875:Middle Aged; D018761:Multiple Endocrine Neoplasia Type 1 / Q000097:blood; D010179:Pancreas / Q000098:blood supply / Q000000981:diagnostic imaging; D012680:Sensitivity and Specificity
D005755:Gastrins; D002125:Calcium Gluconate