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Updated: May 23, 2026

Roux-en-Y Gastric Bypass Operation in Rats
Published on: June 11, 2012
Functional imaging in hyperinsulinemic hypoglycemia after gastric bypass surgery for morbid obesity
Loek J M de Heide1, Andor W J M Glaudemans, Peter H N Oomen
1University Medical Center Groningen, De Brug 4.069, AA 31, P.O. Box 30.001, 9700 RB Groningen, The Netherlands.
Context:
Hyperinsulinemic hypoglycemia after Roux-en-Y gastric bypass (RYGB) has been increasingly reported. It is induced by β-cell hyperplasia often referred to as nesidioblastosis. Positron emission tomography (PET) with [11C]-5-hydroxytryptophan ((11)C-HTP) and 6-[18F]fluoro-3,4-dihydroxy-l-phenylalanine ((18)F-DOPA) has been successfully applied to image neuroendocrine tumors. No data are available of the usefulness of these functional imaging techniques in post-RYGB in this new endocrine disorder, neither for diagnostic purposes nor for follow-up.
Objective:
We present a patient with post-RYGB hypoglycemia who underwent (11)C-HTP and (18)F-DOPA PET scintigraphy for diagnostic purposes and to evaluate the effect of additional laparoscopic adjustable banding of the pouch as a surgical therapy for this disorder.
Patient:
We describe a woman with biochemically confirmed post-RYGB hypoglycemia who showed diffuse uptake of the (11)C-HTP and (18)F-DOPA tracers in the entire pancreas. After failure of dietary and medical treatment options, she underwent a laparoscopic adjustable banding for pouch dilatation. Subjective improvement was noted, which coincided with decreased uptake of (18)F-DOPA and (11)C-HTP in the head of the pancreas.
Conclusions:
Functional imaging by (18)F-DOPA- and (11)C-HTP-PET can accurately visualize diffuse endocrine pancreatic activity in post-gastric bypass hyperinsulinemic hypoglycemia. Both (11)C-HTP- and (18)F-DOPA-PET imaging appear to have a similar diagnostic performance in the presented case, and uptake of both tracers potentially relates to disease activity after surgical intervention.

