title: 99mTc Labeled Glucagon-Like Peptide-1-Analogue (99mTc-GLP1) Scintigraphy in the Management of Patients with Occult Insulinoma.
abstract: BACKGROUND
  The aim of this study was to assess the utility of [Lys40(Ahx-HYNIC-99mTc/EDDA)NH2]-exendin-4 scintigraphy in the management of patients with hypoglycemia, particularly in the detection of occult insulinoma.
  
  
  METHODS
  Forty patients with hypoglycemia and increased/confusing results of serum insulin and C-peptide concentration and negative/inconclusive results of other imaging examinations were enrolled in the study. In all patients GLP-1 receptor imaging was performed to localise potential pancreatic lesions.
  
  
  RESULTS
  Positive results of GLP-1 scintigraphy were observed in 28 patients. In 18 patients postsurgical histopathological examination confirmed diagnosis of insulinoma. Two patients had contraindications to the surgery, one patient did not want to be operated. One patient, who presented with postprandial hypoglycemia, with positive result of GLP-1 imaging was not qualified for surgery and is in the observational group. Eight patients were lost for follow up, among them 6 patients with positive GLP-1 scintigraphy result. One patient with negative scintigraphy was diagnosed with malignant insulinoma. In two patients with negative scintigraphy Munchausen syndrome was diagnosed (patients were taking insulin). Other seven patients with negative results of 99mTcGLP-1 scintigraphy and postprandial hypoglycemia with C-peptide and insulin levels within the limits of normal ranges are in the observational group. We would like to mention that 99mTc-GLP1-SPECT/CT was also performed in 3 pts with nesidioblastosis (revealing diffuse tracer uptake in two and a focal lesion in one case) and in two patients with malignant insulinoma (with the a focal uptake in the localization of a removed pancreatic headin one case and negative GLP-1 1 scintigraphy in the other patient).
  
  
  CONCLUSIONS
  99mTc-GLP1-SPECT/CT could be helpful examination in the management of patients with hypoglycemia enabling proper localization of the pancreatic lesion and effective surgical treatment. This imaging technique may eliminate the need to perform invasive procedures in case of occult insulinoma.
authors.affiliation: Department of Endocrinology, Jagiellonian University Medical College, Kraków, Poland.
authors.forename: Anna
authors.initials: A
authors.lastname: Sowa-Staszczak
authors.affiliation: Department of Endocrinology, Jagiellonian University Medical College, Kraków, Poland.
authors.forename: Małgorzata
authors.initials: M
authors.lastname: Trofimiuk-Müldner
authors.affiliation: Department of Endocrinology, Jagiellonian University Medical College, Kraków, Poland.
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Stefańska
authors.affiliation: Department of Endocrinology, Jagiellonian University Medical College, Kraków, Poland.
authors.forename: Monika
authors.initials: M
authors.lastname: Tomaszuk
authors.affiliation: Department of Endocrinology, Jagiellonian University Medical College, Kraków, Poland.
authors.forename: Monika
authors.initials: M
authors.lastname: Buziak-Bereza
authors.affiliation: Department of Endocrinology, Jagiellonian University Medical College, Kraków, Poland.
authors.forename: Aleksandra
authors.initials: A
authors.lastname: Gilis-Januszewska
authors.affiliation: Department of Endocrinology, Jagiellonian University Medical College, Kraków, Poland.
authors.forename: Agata
authors.initials: A
authors.lastname: Jabrocka-Hybel
authors.affiliation: Department of Endocrinology, University Hospital, Kraków, Poland.
authors.forename: Bogusław
authors.initials: B
authors.lastname: Głowa
authors.affiliation: Department of Metabolic Diseases, Jagiellonian University Medical College, Kraków, Poland.
authors.forename: Maciej
authors.initials: M
authors.lastname: Małecki
authors.affiliation: Department of Endocrinology, Medical University of Warsaw, Warszawa, Poland.
authors.forename: Tomasz
authors.initials: T
authors.lastname: Bednarczuk
authors.affiliation: Department of Endocrinology and Radioisotopic Therapy, Military Institute of Medicine, Warszawa, Poland.
authors.forename: Grzegorz
authors.initials: G
authors.lastname: Kamiński
authors.affiliation: Department of Endocrinology and Nuclear Medicine, Holycross Cancer Center, Kielce, Poland.
authors.forename: Aldona
authors.initials: A
authors.lastname: Kowalska
authors.affiliation: Radioisotope Center POLATOM, National Centre for Nuclear Research, Otwock, Poland.
authors.forename: Renata
authors.initials: R
authors.lastname: Mikołajczak
authors.affiliation: Radioisotope Center POLATOM, National Centre for Nuclear Research, Otwock, Poland.
authors.forename: Barbara
authors.initials: B
authors.lastname: Janota
authors.affiliation: Department of Endocrinology, Jagiellonian University Medical College, Kraków, Poland.
authors.forename: Alicja
authors.initials: A
authors.lastname: Hubalewska-Dydejczyk
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001786:Blood Glucose / Q000378:metabolism; D000077270:Exenatide; D005260:Female; D052216:Glucagon-Like Peptide 1 / Q000737:chemistry*; D006801:Humans; D007003:Hypoglycemia / Q000097:blood / Q000150:complications / Q000000981:diagnostic imaging; D007340:Insulinoma / Q000150:complications / Q000000981:diagnostic imaging*; D007553:Isotope Labeling; D008297:Male; D008875:Middle Aged; D015609:Organotechnetium Compounds / Q000737:chemistry*; D010455:Peptides / Q000737:chemistry; D011877:Radionuclide Imaging; D014688:Venoms / Q000737:chemistry; D055815:Young Adult
chemical_list: D001786:Blood Glucose; D015609:Organotechnetium Compounds; D010455:Peptides; D014688:Venoms; D052216:Glucagon-Like Peptide 1; D000077270:Exenatide