title: Functional imaging in hyperinsulinemic hypoglycemia after gastric bypass surgery for morbid obesity.
abstract: BACKGROUND
  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.
  
  
  METHODS
  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.
authors.affiliation: University Medical Center Groningen, De Brug 4.069, AA 31, P.O. Box 30.001, 9700 RB Groningen, The Netherlands.
authors.forename: Loek J M
authors.initials: LJ
authors.lastname: de Heide
authors.forename: Andor W J M
authors.initials: AW
authors.lastname: Glaudemans
authors.forename: Peter H N
authors.initials: PH
authors.lastname: Oomen
authors.forename: Jan A
authors.initials: JA
authors.lastname: Apers
authors.forename: Eric R E
authors.initials: ER
authors.lastname: Totté
authors.forename: André P
authors.initials: AP
authors.lastname: van Beek
mesh_terms: D000328:Adult; D002250:Carbon Radioisotopes; D004295:Dihydroxyphenylalanine / Q000031:analogs & derivatives; D005260:Female; D019788:Fluorodeoxyglucose F18; D015390:Gastric Bypass / Q000009:adverse effects*; D006801:Humans; D006946:Hyperinsulinism / Q000000981:diagnostic imaging / Q000209:etiology; D007003:Hypoglycemia / Q000000981:diagnostic imaging* / Q000209:etiology; D046768:Nesidioblastosis / Q000000981:diagnostic imaging / Q000209:etiology; D009767:Obesity, Morbid / Q000601:surgery*; D049268:Positron-Emission Tomography / Q000379:methods*; D011183:Postoperative Complications / Q000000981:diagnostic imaging*
chemical_list: D002250:Carbon Radioisotopes; D019788:Fluorodeoxyglucose F18; C043437:fluorodopa F 18; D004295:Dihydroxyphenylalanine