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Imaging and radiotherapy targeting the glucose-dependent insulinotropic polypeptide receptor (GIPR) could potentially benefit the management of neuroendocrine neoplasms (NENs), complementing clinically established radiopharmaceuticals. The aim of this study was to evaluate a GIPR-targeting positron emission tomography (PET) radioligand with receptor-specific binding, fast blood clearance, and low liver background uptake. The peptide DOTA-bioconjugate, C803-GIP, was developed based on the sequence of the endogenous GIP(1-30) and synthetic exendin-4 peptides with selective amino acid mutations to combine their specificity for the GIPR and in vivo stability, respectively. The Ga-68-labeled bioconjugate was evaluated in vitro in terms of binding affinity, specificity, and internalization in HEK293 cells transfected with the human GIPR, GLP1, or GCG receptors and in sections of human insulinoma and NENs. In vivo binding specificity, biodistribution, and tissue background were investigated in mice bearing huGIPR-HEK293 xenografts and in a pig. Ex vivo organ distribution, pharmacokinetics, and dosimetry were studied in normal rats. [Ga-68]Ga-C803-GIP was stable and demonstrated a high affinity to the huGIPR-HEK293 cells. Binding specificity was demonstrated in vitro in frozen sections of NENs and huGIPR-HEK293 cells. No specific uptake was observed in the negative controls of huGLP1R and huGCGR cells. A novel rationally designed PET radioligand, [Ga-68]Ga-C803-GIP, demonstrated promising binding characteristics and specificity towards the GIPR.

Imaging and radiotherapy targeting the glucose-dependent insulinotropic polypeptide receptor (GIPR) could potentially benefit the management of neuroendocrine neoplasms (NENs), complementing clinically established radiopharmaceuticals. The aim of this study was to evaluate a GIPR-targeting positron emission tomography (PET) radioligand with receptor-specific binding, fast blood clearance, and low liver background uptake. The peptide DOTA-bioconjugate, C803-GIP, was developed based on the sequence of the endogenous GIP(1-30) and synthetic exendin-4 peptides with selective amino acid mutations to combine their specificity for the GIPR and in vivo stability, respectively. The Ga-68-labeled bioconjugate was evaluated in vitro in terms of binding affinity, specificity, and internalization in HEK293 cells transfected with the human GIPR, GLP1, or GCG receptors and in sections of human insulinoma and NENs. In vivo binding specificity, biodistribution, and tissue background were investigated in mice bearing huGIPR-HEK293 xenografts and in a pig. Ex vivo organ distribution, pharmacokinetics, and dosimetry were studied in normal rats. [Ga-68]Ga-C803-GIP was stable and demonstrated a high affinity to the huGIPR-HEK293 cells. Binding specificity was demonstrated in vitro in frozen sections of NENs and huGIPR-HEK293 cells. No specific uptake was observed in the negative controls of huGLP1R and huGCGR cells. A novel rationally designed PET radioligand, [Ga-68]Ga-C803-GIP, demonstrated promising binding characteristics and specificity towards the GIPR.

Imaging and radiotherapy targeting the glucose-dependent insulinotropic polypeptide receptor (GIPR) could potentially benefit the management of neuroendocrine neoplasms (NENs), complementing clinically established radiopharmaceuticals. The aim of this study was to evaluate a GIPR-targeting positron emission tomography (PET) radioligand with receptor-specific binding, fast blood clearance, and low liver background uptake. The peptide DOTA-bioconjugate, C803-GIP, was developed based on the sequence of the endogenous GIP(1-30) and synthetic exendin-4 peptides with selective amino acid mutations to combine their specificity for the GIPR and in vivo stability, respectively. The Ga-68-labeled bioconjugate was evaluated in vitro in terms of binding affinity, specificity, and internalization in HEK293 cells transfected with the human GIPR, GLP1, or GCG receptors and in sections of human insulinoma and NENs. In vivo binding specificity, biodistribution, and tissue background were investigated in mice bearing huGIPR-HEK293 xenografts and in a pig. Ex vivo organ distribution, pharmacokinetics, and dosimetry were studied in normal rats. [Ga-68]Ga-C803-GIP was stable and demonstrated a high affinity to the huGIPR-HEK293 cells. Binding specificity was demonstrated in vitro in frozen sections of NENs and huGIPR-HEK293 cells. No specific uptake was observed in the negative controls of huGLP1R and huGCGR cells. A novel rationally designed PET radioligand, [Ga-68]Ga-C803-GIP, demonstrated promising binding characteristics and specificity towards the GIPR.

Imaging and radiotherapy targeting the glucose-dependent insulinotropic polypeptide receptor (GIPR) could potentially benefit the management of neuroendocrine neoplasms (NENs), complementing clinically established radiopharmaceuticals. The aim of this study was to evaluate a GIPR-targeting positron emission tomography (PET) radioligand with receptor-specific binding, fast blood clearance, and low liver background uptake. The peptide DOTA-bioconjugate, C803-GIP, was developed based on the sequence of the endogenous GIP(1-30) and synthetic exendin-4 peptides with selective amino acid mutations to combine their specificity for the GIPR and in vivo stability, respectively. The Ga-68-labeled bioconjugate was evaluated in vitro in terms of binding affinity, specificity, and internalization in HEK293 cells transfected with the human GIPR, GLP1, or GCG receptors and in sections of human insulinoma and NENs. In vivo binding specificity, biodistribution, and tissue background were investigated in mice bearing huGIPR-HEK293 xenografts and in a pig. Ex vivo organ distribution, pharmacokinetics, and dosimetry were studied in normal rats. [Ga-68]Ga-C803-GIP was stable and demonstrated a high affinity to the huGIPR-HEK293 cells. Binding specificity was demonstrated in vitro in frozen sections of NENs and huGIPR-HEK293 cells. No specific uptake was observed in the negative controls of huGLP1R and huGCGR cells. A novel rationally designed PET radioligand, [Ga-68]Ga-C803-GIP, demonstrated promising binding characteristics and specificity towards the GIPR.

Insulinomas are rare pancreatic neuroendocrine tumours. Most patients can be cured with surgery, but patients with a metastatic disease show impaired survival. The aim of this study was to evaluate somatostatin receptor (SSTR) 1‐5 expression in insulinomas and to correlate the expression profile with clinicopathological variables and with patient outcome. This retrospective study involved 52 insulinoma patients. After histological re-evaluation, formalin-fixed paraffin-embedded tissue samples were processed into tissue microarrays and stained immunohistochemically with monoclonal SSTR1‐5 antibodies. All the 52 tumours (49 non-metastatic, 3 metastatic) expressed at least one SSTR subtype. SSTR2 was expressed most frequently (71%), followed by SSTR3 (33%), SSTR1 (27%), SSTR5 (6%) and SSTR4 (0%). SSTR3 expression was associated with a larger tumour size (median diameter 19 mm vs. 13 mm, p = 0.043), and SSTR3 and SSTR5 expression were associated with impaired overall survival [HR 3.532 (95% CI 1.106‐11,277), p = 0.033, and HR 6.805 (95% CI 1.364‐33.955), p = 0.019 respectively]. Most insulinomas express SSTR2, which may be utilized in diagnostic imaging, and in planning individualized treatment strategies for insulinoma patients. Further studies are needed to clarify the association between SSTR profile and overall survival.

Octreotide is used in patients with insulinomas to treat hypoglycemia, and somatostatin receptor (SSTR) 2 expression is important for its efficacy. We report a case of insulinoma in a 50-year-old woman that responded to an octreotide test, showed accumulation in somatostatin scintigraphy, and was positive for SSTR2A on immunostaining.

Imaging and radiotherapy targeting the glucose-dependent insulinotropic polypeptide receptor (GIPR) could potentially benefit the management of neuroendocrine neoplasms (NENs), complementing clinically established radiopharmaceuticals. The aim of this study was to evaluate a GIPR-targeting positron emission tomography (PET) radioligand with receptor-specific binding, fast blood clearance, and low liver background uptake. The peptide DOTA-bioconjugate, C803-GIP, was developed based on the sequence of the endogenous GIP(1-30) and synthetic exendin-4 peptides with selective amino acid mutations to combine their specificity for the GIPR and in vivo stability, respectively. The Ga-68-labeled bioconjugate was evaluated in vitro in terms of binding affinity, specificity, and internalization in HEK293 cells transfected with the human GIPR, GLP1, or GCG receptors and in sections of human insulinoma and NENs. In vivo binding specificity, biodistribution, and tissue background were investigated in mice bearing huGIPR-HEK293 xenografts and in a pig. Ex vivo organ distribution, pharmacokinetics, and dosimetry were studied in normal rats. [Ga-68]Ga-C803-GIP was stable and demonstrated a high affinity to the huGIPR-HEK293 cells. Binding specificity was demonstrated in vitro in frozen sections of NENs and huGIPR-HEK293 cells. No specific uptake was observed in the negative controls of huGLP1R and huGCGR cells. A novel rationally designed PET radioligand, [Ga-68]Ga-C803-GIP, demonstrated promising binding characteristics and specificity towards the GIPR.

In the light of theranostics/radiotheranostics and prospective of personalized medicine in diabetes and oncology, this review presents prior and current advances in the development of radiolabeled imaging and radiotherapeutic exendin-based agents targeting glucagon-like peptide-1 receptor. The review covers chemistry, preclinical, and clinical evaluation. Such critical aspects as structure-activity-relationship, stability, physiological potency, kidney uptake, and dosimetry are discussed.

In the light of theranostics/radiotheranostics and prospective of personalized medicine in diabetes and oncology, this review presents prior and current advances in the development of radiolabeled imaging and radiotherapeutic exendin-based agents targeting glucagon-like peptide-1 receptor. The review covers chemistry, preclinical, and clinical evaluation. Such critical aspects as structure-activity-relationship, stability, physiological potency, kidney uptake, and dosimetry are discussed.

BACKGROUND: Insulinomas are rare tumours of the pancreas and the most common cause of hypoglycaemia in non-diabetic adults. They can be cured by surgery but require precise localization. The aim of this study was to assess the utility of the selective intra-arterial calcium stimulation test (SIACST) in patients with an insulinoma to correctly localize the tumour. METHOD(S): Medical records of patients with a diagnosis of insulinoma or who underwent an SIACST were retrospectively reviewed. Localization of lesions by SIACST was compared to endoscopic ultrasound and radionuclide imaging studies and verified against findings at surgery. RESULT(S): A total of 24 patients (mean age 58years, 16 females, 20 with insulinoma) underwent SIACST. The SIACST correctly localized the insulinoma in 17 of 20 patients (85%). Localization rate for computed tomography was 55% and 75% for endoscopic ultrasound and glucagon-like peptide-1 receptor scan. CONCLUSION(S): SIACST provided incremental diagnostic information in patients with insulinoma who had equivocal non-invasive imaging preoperatively. This technique remains an essential diagnostic tool when a lesion is not localized by other methods.Copyright © 2020 Royal Australasian College of Surgeons.

BACKGROUND: Insulinomas are rare tumours of the pancreas and the most common cause of hypoglycaemia in non-diabetic adults. They can be cured by surgery but require precise localization. The aim of this study was to assess the utility of the selective intra-arterial calcium stimulation test (SIACST) in patients with an insulinoma to correctly localize the tumour. METHOD(S): Medical records of patients with a diagnosis of insulinoma or who underwent an SIACST were retrospectively reviewed. Localization of lesions by SIACST was compared to endoscopic ultrasound and radionuclide imaging studies and verified against findings at surgery. RESULT(S): A total of 24 patients (mean age 58years, 16 females, 20 with insulinoma) underwent SIACST. The SIACST correctly localized the insulinoma in 17 of 20 patients (85%). Localization rate for computed tomography was 55% and 75% for endoscopic ultrasound and glucagon-like peptide-1 receptor scan. CONCLUSION(S): SIACST provided incremental diagnostic information in patients with insulinoma who had equivocal non-invasive imaging preoperatively. This technique remains an essential diagnostic tool when a lesion is not localized by other methods.Copyright © 2020 Royal Australasian College of Surgeons.

In the light of theranostics/radiotheranostics and prospective of personalized medicine in diabetes and oncology, this review presents prior and current advances in the development of radiolabeled imaging and radiotherapeutic exendin-based agents targeting glucagon-like peptide-1 receptor. The review covers chemistry, preclinical, and clinical evaluation. Such critical aspects as structure-activity-relationship, stability, physiological potency, kidney uptake, and dosimetry are discussed.

BACKGROUND: Insulinomas are usually benign, small-sized, well-encapsulated and often solitary pancreatic tumors. Currently, enucleation is the treatment of choice for sporadic solitary insulinoma if diameter is less than 2cm and the structural integrity of the pancreatic duct can be maintained. However, the procedure has a risk of postoperative complications, and especially of pancreatic fistula. There is growing interest in endoscopic ultrasound-guided radiofrequency ablation (EUS-RFA) as an effective and less invasive alternative treatment for benign sporadic insulinoma. METHOD: We retrospectively analyzed the efficacy and safety of EUS-RFA in four patients with benign localized insulinoma treated in our tertiary care center between June 2018 and November 2019. EUS-RFA was performed with a EUS-guided RFA 19-gauge needle electrode (Starmed; Taewoong Medical, Seoul, South Korea) that released energy at 50W up to 100 Ohms impedance. RESULTS: The series comprised three women and one man, with a median age of 58 years (range 52-82 years). Mean tumor size was 12mm. Although three of the four patients would have been eligible for surgery, EUS-RFA was proposed to them. Symptomatic and biological improvement occurred immediately, generally straight after the procedure, in all patients, and no serious complications were observed. During the mean follow-up period of 22 months, no symptom recurrence was observed. CONCLUSIONS: This preliminary report in 4 patients showed that EUS-RFA was an effective and relatively safe alternative treatment, devoid of major complications, for benign sporadic insulinoma. Larger-scale prospective multicenter studies are, however, needed to confirm the long-term effectiveness and safety of this novel technique.

Aims. The diagnosis of hypoglycemia in ferrets (Mustela putorius furo) is based on the detection of a blood glucose level below 60-70 mg / dl. A blood glucose concentration below these levels is very suggestive of pancreatic beta cell tumor (insulinoma), which comprises of approximately 25% of all neoplasms diagnosed in this species. This study aims to check if the low blood glucose values obtained through the use of portable glucometers are reliable as a method of diagnosing hypoglycemia in this species. Material and methods. In this study, 31 samples of ferrets blood of different ages and sexes are analyzed, using three types of portable glucometers, comparing these results with the measurements obtained by a liquid biochemistry analyzer using the glucose oxidase method, considered as one of the standard measurement methods. Results. One of the three glucometers used in this study underestimates blood glucose values in this species, while another overestimates them, which is a systematic error (predictable) of the equipment that could be solved by calibrating them for this species. The other glucometer is more consistent with the reference values, but has a high random error (unpredictable), that is more difficult to correct. Therefore none of the three teams would be adequate to make a reliable diagnosis of hypoglycemia in ferrets. Conclusions. These results indicate that blood glucose concentrations in ferrets should be confirmed with a validated laboratory analyzer to reliably diagnose hypoglycemia, and blood glucose meters used only to monitor the disease., Objetivo. El diagnóstico de la hipoglucemia en hurones (Mustela putorius furo) se basa en la detección de un nivel de glucosa en la sangre inferior a 60- 70 mg / dl. Una concentración de glucosa en sangre por debajo de estos niveles es muy sugestiva de tumor de células beta pancreáticas (insulinoma), que comprende aproximadamente el 25% de todas las neoplasias diagnosticadas en esta especie. En este estudio se pretende comprobar si los bajos valores de glucosa en sangre obtenidos mediante el uso de glucómetros portátiles son fiables como método de diagnóstico de hipoglucemia en esta especie. Material y métodos. En este estudio se analizan 31 muestras de sangre de hurones de distinta edad y sexo, mediante el uso de tres tipos de glucómetros portátiles, comparando dichos resultados con las medidas obtenidas mediante un analizador de bioquímica líquida que usa el método de la glucosa oxidasa, considerado como uno de los métodos estándar de medida. Resultados. Uno de los tres glucómetros utilizado en este estudio subestima los valores de glucosa en sangre en esta especie, mientras que otro los sobreestima, lo que supone un error sistemático (predecible) de los equipos que se podría solucionar calibrándolos para esta especie. El otro glucómetro que presenta mayor concordancia con los valores de referencia presenta un error aleatorio elevado (impredecible) más difícil de corregir. Por tanto ninguno de los tres equipos sería adecuado para realizar un diagnóstico fiable de hipoglucemia en hurones. Conclusiones. Estos resultados indican que las concentraciones de glucosa en sangre en hurones deben confirmarse con un analizador de laboratorio validado para realizar el diagnóstico de hipoglucemia de forma fiable, y los glucómetros usarse sólo para hacer un seguimiento de la enfermedad.

Insulinomas are the most frequent etiology of hypoglycemia in a non-diabetic patient and the most common functional neuroendocrine tumors of the pancreas, with an annual incidence of about 4 cases per million1, 2. The majority of insulinomas are “well-differentiated endocrine tumors” or grade 1 tumors, as defined by World Health Organization3 . Most tumors are benign, solitary and occur sporadically. However, about 10% are associated with multiple endocrine neoplasia type 1 (MEN-1)1,2. Despite the majority being benign tumors, hypoglycemic symptoms caused by the hyperinsulinemia are frequently debilitating4 . Whipple triad (hypoglycemia, symptoms of hypoglycemia – either adrenergic or neuroglycopenic – and relief of these symptoms after administration of glucose) is usually present and should alert to the diagnosis2,5. After the diagnosis is made, locating the tumor can be challenging because most tumors are small4 . Nonetheless, locating the tumor is crucial, once the only definite treatment is surgical excision1,2. The majority of patients reach normalization of glucose levels after surgery. Incomplete resection leads to persistent symptoms and although uncommon in sporadic insulinomas, recurrence can be as high as 20% in patients with MEN-1 syndrome6,7.

Objective: Insulinomas are rare pancreatic neoplasms, which can usually be cured by surgery. As the diagnostic delay is often long and the prolonged hyperinsulinemia may have long‐term effects on health and the quality of life, we studied the long‐term health‐related quality of life (HRQoL) in insulinoma patients. Design, patients and measurements: The HRQoL of adults diagnosed with an insulinoma in Finland in 1980‐2010 was studied with the 15D instrument, and the results were compared to those of an age‐ and gender‐matched sample of the general population. The minimum clinically important difference in the total 15D score has been defined as ±0.015. The clinical characteristics, details of insulinoma diagnosis and treatment, and the current health status of the subjects were examined to specify the possible determinants of long‐term HRQoL. Results: Thirty‐eight insulinoma patients participated in the HRQoL survey (response rate 75%). All had undergone surgery with a curative aim, a median of 13 (min 7, max 34) years before the survey. The insulinoma patients had a clinically importantly and statistically significantly better mean 15D score compared with the controls (0.930 ± 0.072 vs 0.903 ± 0.039, P = .046) and were significantly better off regarding mobility, usual activities and eating. Among the insulinoma patients, younger age at the time of survey, higher level of education and smaller number of chronic diseases were associated with better overall HRQoL. Conclusions: In the long term, the overall HRQoL of insulinoma patients is slightly better than that of the general population.

In the light of theranostics/radiotheranostics and prospective of personalized medicine in diabetes and oncology, this review presents prior and current advances in the development of radiolabeled imaging and radiotherapeutic exendin-based agents targeting glucagon-like peptide-1 receptor. The review covers chemistry, preclinical, and clinical evaluation. Such critical aspects as structure-activity-relationship, stability, physiological potency, kidney uptake, and dosimetry are discussed.

In the light of theranostics/radiotheranostics and prospective of personalized medicine in diabetes and oncology, this review presents prior and current advances in the development of radiolabeled imaging and radiotherapeutic exendin-based agents targeting glucagon-like peptide-1 receptor. The review covers chemistry, preclinical, and clinical evaluation. Such critical aspects as structure-activity-relationship, stability, physiological potency, kidney uptake, and dosimetry are discussed.

The multiple endocrine neoplasia type 1 (MEN1) is a rare syndrome characterized by the predisposition to developing multiple endocrine and non-endocrine tumors, typically characterized by the association between parathyroid gland hyperplasia or tumors, gastroenteropancreatic tumors and pituitary adenomas. The MEN1 gene is located on the long arm of chromosome 11 (11q13) and it encodes for the protein “menin”. We here reported the case of a MEN1-patient, affected by primary hyperparathyroidism, insulinoma, pituitary non-hyperfunctioning adenoma and bilateral adrenal masses, carrying a novel heterozygous pathogenic variant (c.1252_1254delGACinsAT), located in exon 9 of MEN1 gene.

In the light of theranostics/radiotheranostics and prospective of personalized medicine in diabetes and oncology, this review presents prior and current advances in the development of radiolabeled imaging and radiotherapeutic exendin-based agents targeting glucagon-like peptide-1 receptor. The review covers chemistry, preclinical, and clinical evaluation. Such critical aspects as structure-activity-relationship, stability, physiological potency, kidney uptake, and dosimetry are discussed.

OBJECTIVES: To determine 1) the sensitivity of contrast-enhanced CT (CECT) for detection of primary canine insulinomas and metastases 2) the sensitivity of CECT to locate canine insulinomas within the pancreas and 3) the CECT attenuation pattern of canine insulinomas and post-contrast phase in which insulinomas have the best visibility.METHODS: A retrospective review was performed of the medical records of 27 canine insulinoma patients. Simultaneous occurrence of blood glucose < 3.5 mmol/L (reference interval: 4.2-5.8 mmol/L) and plasma insulin > 10 mIU/L (reference interval: 1.4-24.5 mIU/L) were considered diagnostic for insulinoma. The dogs had a mean age of 9.0 ± 1.7 (SD) years and comprised 11 males and 17 females.RESULTS: Using CECT-scans, 26/27 insulinomas were successfully detected. However, CECT-scans predicted the correct location of insulinomas within the pancreas in only 14/27 dogs. In 9/13 inaccurately located insulinoma cases, the location error was major. There was no significant difference between triple, double and single-phase CECT-scans with location accuracies of 54%, 50% and 50%, respectively. Also, there was no specific post-contrast phase in which insulinomas could be visualised best. Detection of lymph node metastases with CECT-scans had a sensitivity of 67% (10/15 lymph node metastases). Detection of liver metastases had a sensitivity of 75% (6/8 liver metastases). This study highlights that major location errors mainly occurred if single- or double-phase CECT-scans were used (6/9 cases).CONCLUSION: It is suggested that triple-phase CECT-scans have superior outcome over single- or double-phase CECT-scans in pre-operative imaging of canine insulinomas.

Well-established criteria for evaluating the response to treatment and the appropriate follow-up of individual patients are critical in clinical oncology. The current evidence-based data on these issues in terms of the management of gastroenteropancreatic (GEP) neuroendocrine neoplasms (NEN) are unfortunately limited. This document by the Italian Association of Clinical Endocrinologists (AME) on the criteria for the follow-up of GEP-NEN patients is aimed at providing comprehensive recommendations for everyday clinical practice based on both the best available evidence and the combined opinion of an interdisciplinary panel of experts. The initial risk stratification of patients with NENs should be performed according to the grading, staging and functional status of the neoplasm and the presence of an inherited syndrome. The evaluation of response to the initial treatment, and to the subsequent therapies for disease progression or recurrence, should be based on a cost-effective, risk-effective and timely use of the appropriate diagnostic resources. A multidisciplinary evaluation of the response to the treatment is strongly recommended and, at every step in the follow-up, it is mandatory to assess the disease state and the patient performance status, comorbidities, and recent clinical evolution. Local expertise, available technical resources and the patient preferences should always be evaluated while planning the individual clinical management of GEP-NENs.

X-linked lissencephaly with abnormal genitalia is a rare and devastating syndrome. The authors present an infant with a multisystem phenotype where the intestinal manifestations were as life limiting as the central nervous system features. Severe chronic diarrhea resulted in failure to thrive, dehydration, electrolyte derangements, long-term hospitalization, and prompted transition to palliative care. Other multisystem manifestations included megacolon, colitis, pancreatic insufficiency hypothalamic dysfunction, hypothyroidism, and hypophosphatasia. A novel aristaless-related homeobox gene mutation, c.1136G>T/p.R379L, was identified. This case contributes to the clinical, histological, and molecular understanding of the multisystem nature of this disorder, especially the role of ARX in the development of the enteroendocrine system.Copyright © The Author(s) 2017.

Background: Hypoglycemic manifestations are highly variable in patients with an insulinoma and largely independent of tumour size and severity of insulin hypersecretion. Objectives: We investigated the clinical, biological and tumoral characteristics of insulinomas in a large monocentric series of patients and we evaluated their insulin sensitivity before and after successful pancreatic surgery. Patients and methods: This was a retrospective analysis of 40 patients treated for an insulinoma between 1982 and 2012 in our academic hospital. Insulin sensitivity and beta cell function were evaluated by a HOMA test outside hypoglycaemic episodes in a large subset of these patients. Results: The mean age at onset of symptoms was 48.8. ±. 20.1 years and the mean age at diagnosis was 50.7. ±. 19.9 years. Neuroglycopenic symptoms were observed in 90% of patients. The most effective preoperative imaging technique to localize the tumour was endoscopic ultrasound. Insulin sensitivity was greatly reduced in patients with insulinoma (38.9%. ±. 22.3%), while beta cells function was increased (359.0. ±. 171.5%), but to a variable extent (range: 110.6-678.6%). After complete resection of the tumour and remission of hypoglycemic episodes, insulin sensitivity increased in all evaluated subjects (72.8. ±. 36.7%) and normalized in the majority. Conclusion: Although neuroglycopenic symptoms are present in most patients, diagnosis of insulinoma is often delayed. Endoscopic ultrasound remains the most sensitive preoperative technique to localize the tumour. We also show that in response to chronic hyperinsulinemia, patients with insulinoma develop protective mechanisms responsible for a marked insulin resistance, which is reversible after complete resection of the tumour.

The article describes a clinical case of insulinoma, which has long been regarded as atypical epilepsy. Errors made during the diagnosis and treatment are analyzed, the comparison with literature data is carried out. Conclusions. For the diagnosis of organic hyperinsulinism, it is necessary to determine the insulin and C-peptide during hypoglycemia; normal indexes of insulin and C-peptide in case of hypoglycemia and respective symptoms confirm the diagnosis. For topical diagnosis of insulinoma contrast CT or MRI should be used. Laparoscopic enucleation of insulinoma is the best method of treatment. In early postoperative period after insulinoma enucleation reactive pancreatitis can occur and will demand specific treatment. The unusual course of epilepsy resistant to treatment should be reason for excluding other possible causes of seizures, including organic hyperinsulinism., У статті описаний клінічний випадок інсуліноми, клінічна картина якої довго розцінювалася як нетиповий перебіг епілепсії, резистентної до терапії. Проаналізовані помилки, які були допущені під час діагностики та лікування, проведене порівняння з даними літератури. Висновки. Для діагностики органічного гіперінсулінізму необхідне визначення інсуліну і С-пептиду на тлі гіпоглікемії; нормальні показники інсуліну і С-пептиду на тлі встановленої гіпоглікемії і відповідних симптомів підтверджують діагноз. Для топічної діагностики інсуліноми мають застосовуватися КТ або МРТ з обов’язковим контрастним посиленням. Лапароскопічна енуклеація інсуліноми – найкращий метод лікування. У ранньому післяопераційному періоді може виникати реактивний панкреатит, що потребує відповідного лікування. Нетиповий перебіг епілепсії з резистентністю до терапії має слугувати приводом для виключення інших можливих причин судом, у тому числі органічного гіперінсулінізму.

X-linked lissencephaly with abnormal genitalia is a rare and devastating syndrome. The authors present an infant with a multisystem phenotype where the intestinal manifestations were as life limiting as the central nervous system features. Severe chronic diarrhea resulted in failure to thrive, dehydration, electrolyte derangements, long-term hospitalization, and prompted transition to palliative care. Other multisystem manifestations included megacolon, colitis, pancreatic insufficiency hypothalamic dysfunction, hypothyroidism, and hypophosphatasia. A novel aristaless-related homeobox gene mutation, c.1136G>T/p.R379L, was identified. This case contributes to the clinical, histological, and molecular understanding of the multisystem nature of this disorder, especially the role of ARX in the development of the enteroendocrine system.Copyright © The Author(s) 2017.

Multiple endocrine neoplasia type 1 is a rare disease. It is characterized by the neuroendocrine, parathyroid, pituitary, and enteropancreatic tumor involvement. We present the case of a 19 year old patient with symptoms of headache, convulsions and weakness of the four extremities. The presence of hypoglycemia 33mg/dL was confirmed. The electromyographic study showed motor sensory polyneuropathy in all four extremities. The abdominal magnetic resonance showed a tumor in the tail of the pancreas that after the pancreatectomy was confirmed as insulinoma. The glycemia was normalized. In addition, he presented a pituitary macroadenoma, primary hyperparathyroidism and non-functioning adrenal tumor. At 25 years of age, he presented severe headache and amaurosis of the right eye. Axial tomography showed a giant pituitary tumor and in the study of pathology chondroid malignancy (chordoma) was diagnosed., La neoplasia endocrina múltiple tipo 1 es una enfermedad de rara presentación. Se caracteriza por el compromiso tumoral neuroendocrino, de paratiroides, hipófisis y enteropancreático. Presentamos el caso de una paciente de 19 años con síntomas de cefalea, convulsiones y debilidad de las cuatro extremidades. Se confirmó la presencia de hipoglicemia 33mg/dL. El estudio elecromiográfico evidenció polineuropatía sensitivo motora en las cuatro extremidades. La resonancia magnética abdominal mostró un tumor en la cola del páncreas que luego de la pancreatectomía se confirmó como insulinoma. La glicemia se normalizó. Además, presentó un macroadenoma hipofisario, hiperparatiroidismo primario y tumor adrenal no funcionante. A los 25 años presentó cefalea intensa y amaurosis de ojo derecho, en la tomografía axial se evidenció tumoración hipofisaria gigante y en estudio de patología se diagnosticó neoplasia maligna condroide (cordoma).

Neoplastic disease is common in ferrets. Approximately half of all tumors diagnosed in ferrets are located in the endocrine or hemolymphatic system. Many factors may influence the choice of treatment. Medical management of adrenal tumors has a greater disease-free period compared to adrenalectomy. In ferrets with an insulinoma, no difference is seen in the mean survival time of medically and surgically treated patients. Aside from medical and surgical treatment modalities, chemotherapy and radiation therapy have also been described in ferrets in other types of tumors. The outcome of these treatment modalities is not always favorable.

[Ga-68]Ga-DO3A-VS-Cys(40)-Exendin-4/PET-CT targeting glucagon like peptide-1 receptor (GLP-1R) has previously demonstrated its potential clinical value for the detection of insulinomas. The production and accessibility of this radiopharmaceutical is one of the critical factors in realization of clinical trials and routine clinical examinations. Previously, the radiopharmaceutical was prepared manually, however larger scale of clinical trials and healthcare requires automation of the production process in order to limit the operator radiation dose as well as improve tracer manufacturing robustness and on-line documentation for enhanced good manufacturing practice (GMP) compliance. A method for Ga-68-labelling of DO3A-VS-Cys(40)-Exendin-4 on a commercially available synthesis platform was developed. Equipment such as Ge-68/Ga-68 generator, synthesis platform, and disposable cassettes for Ga-68-labelling used in the study was purchased from Eckert & Ziegler. DO3A-VS-Cys(40)-Exendin-4 was synthesized in-house. The parameters such as time, temperature, precursor concentration, radical scavenger, buffer concentration, pH, product purification step were investigated and optimised. Reproducible and GMP compliant automated production of [Ga-68]Ga-DO3A-VS-Cys(40)-Exendin-4 was developed. Exendin-4 comprising methionine amino acid residue was prone to oxidation which was strongly influenced by the elevated temperature, radioactivity amount, and precursor concentration. The suppression of the oxidative radiolysis was achieved by addition of ethanol, dihydroxybenzoic acid and ascorbic acid to the reaction buffer as well as by optimizing heating temperature. The non-decay corrected radiochemical yield was 43 +/- 2% with radiochemical purity of over 90% wherein the individual impurity signals in HPLC chromatogram did not exceed 5%. Automated production and quality control methods were established for paving the pathway for broader clinical use of [Ga-68]Ga-DO3A-VS-Cys(40)-Exen

[Ga-68]Ga-DO3A-VS-Cys(40)-Exendin-4/PET-CT targeting glucagon like peptide-1 receptor (GLP-1R) has previously demonstrated its potential clinical value for the detection of insulinomas. The production and accessibility of this radiopharmaceutical is one of the critical factors in realization of clinical trials and routine clinical examinations. Previously, the radiopharmaceutical was prepared manually, however larger scale of clinical trials and healthcare requires automation of the production process in order to limit the operator radiation dose as well as improve tracer manufacturing robustness and on-line documentation for enhanced good manufacturing practice (GMP) compliance. A method for Ga-68-labelling of DO3A-VS-Cys(40)-Exendin-4 on a commercially available synthesis platform was developed. Equipment such as Ge-68/Ga-68 generator, synthesis platform, and disposable cassettes for Ga-68-labelling used in the study was purchased from Eckert & Ziegler. DO3A-VS-Cys(40)-Exendin-4 was synthesized in-house. The parameters such as time, temperature, precursor concentration, radical scavenger, buffer concentration, pH, product purification step were investigated and optimised. Reproducible and GMP compliant automated production of [Ga-68]Ga-DO3A-VS-Cys(40)-Exendin-4 was developed. Exendin-4 comprising methionine amino acid residue was prone to oxidation which was strongly influenced by the elevated temperature, radioactivity amount, and precursor concentration. The suppression of the oxidative radiolysis was achieved by addition of ethanol, dihydroxybenzoic acid and ascorbic acid to the reaction buffer as well as by optimizing heating temperature. The non-decay corrected radiochemical yield was 43 +/- 2% with radiochemical purity of over 90% wherein the individual impurity signals in HPLC chromatogram did not exceed 5%. Automated production and quality control methods were established for paving the pathway for broader clinical use of [Ga-68]Ga-DO3A-VS-Cys(40)-Exen

[Ga-68]Ga-DO3A-VS-Cys(40)-Exendin-4/PET-CT targeting glucagon like peptide-1 receptor (GLP-1R) has previously demonstrated its potential clinical value for the detection of insulinomas. The production and accessibility of this radiopharmaceutical is one of the critical factors in realization of clinical trials and routine clinical examinations. Previously, the radiopharmaceutical was prepared manually, however larger scale of clinical trials and healthcare requires automation of the production process in order to limit the operator radiation dose as well as improve tracer manufacturing robustness and on-line documentation for enhanced good manufacturing practice (GMP) compliance. A method for Ga-68-labelling of DO3A-VS-Cys(40)-Exendin-4 on a commercially available synthesis platform was developed. Equipment such as Ge-68/Ga-68 generator, synthesis platform, and disposable cassettes for Ga-68-labelling used in the study was purchased from Eckert & Ziegler. DO3A-VS-Cys(40)-Exendin-4 was synthesized in-house. The parameters such as time, temperature, precursor concentration, radical scavenger, buffer concentration, pH, product purification step were investigated and optimised. Reproducible and GMP compliant automated production of [Ga-68]Ga-DO3A-VS-Cys(40)-Exendin-4 was developed. Exendin-4 comprising methionine amino acid residue was prone to oxidation which was strongly influenced by the elevated temperature, radioactivity amount, and precursor concentration. The suppression of the oxidative radiolysis was achieved by addition of ethanol, dihydroxybenzoic acid and ascorbic acid to the reaction buffer as well as by optimizing heating temperature. The non-decay corrected radiochemical yield was 43 +/- 2% with radiochemical purity of over 90% wherein the individual impurity signals in HPLC chromatogram did not exceed 5%. Automated production and quality control methods were established for paving the pathway for broader clinical use of [Ga-68]Ga-DO3A-VS-Cys(40)-Exen

[Ga-68]Ga-DO3A-VS-Cys(40)-Exendin-4/PET-CT targeting glucagon like peptide-1 receptor (GLP-1R) has previously demonstrated its potential clinical value for the detection of insulinomas. The production and accessibility of this radiopharmaceutical is one of the critical factors in realization of clinical trials and routine clinical examinations. Previously, the radiopharmaceutical was prepared manually, however larger scale of clinical trials and healthcare requires automation of the production process in order to limit the operator radiation dose as well as improve tracer manufacturing robustness and on-line documentation for enhanced good manufacturing practice (GMP) compliance. A method for Ga-68-labelling of DO3A-VS-Cys(40)-Exendin-4 on a commercially available synthesis platform was developed. Equipment such as Ge-68/Ga-68 generator, synthesis platform, and disposable cassettes for Ga-68-labelling used in the study was purchased from Eckert & Ziegler. DO3A-VS-Cys(40)-Exendin-4 was synthesized in-house. The parameters such as time, temperature, precursor concentration, radical scavenger, buffer concentration, pH, product purification step were investigated and optimised. Reproducible and GMP compliant automated production of [Ga-68]Ga-DO3A-VS-Cys(40)-Exendin-4 was developed. Exendin-4 comprising methionine amino acid residue was prone to oxidation which was strongly influenced by the elevated temperature, radioactivity amount, and precursor concentration. The suppression of the oxidative radiolysis was achieved by addition of ethanol, dihydroxybenzoic acid and ascorbic acid to the reaction buffer as well as by optimizing heating temperature. The non-decay corrected radiochemical yield was 43 +/- 2% with radiochemical purity of over 90% wherein the individual impurity signals in HPLC chromatogram did not exceed 5%. Automated production and quality control methods were established for paving the pathway for broader clinical use of [Ga-68]Ga-DO3A-VS-Cys(40)-Exen

[Ga-68]Ga-DO3A-VS-Cys(40)-Exendin-4/PET-CT targeting glucagon like peptide-1 receptor (GLP-1R) has previously demonstrated its potential clinical value for the detection of insulinomas. The production and accessibility of this radiopharmaceutical is one of the critical factors in realization of clinical trials and routine clinical examinations. Previously, the radiopharmaceutical was prepared manually, however larger scale of clinical trials and healthcare requires automation of the production process in order to limit the operator radiation dose as well as improve tracer manufacturing robustness and on-line documentation for enhanced good manufacturing practice (GMP) compliance. A method for Ga-68-labelling of DO3A-VS-Cys(40)-Exendin-4 on a commercially available synthesis platform was developed. Equipment such as Ge-68/Ga-68 generator, synthesis platform, and disposable cassettes for Ga-68-labelling used in the study was purchased from Eckert & Ziegler. DO3A-VS-Cys(40)-Exendin-4 was synthesized in-house. The parameters such as time, temperature, precursor concentration, radical scavenger, buffer concentration, pH, product purification step were investigated and optimised. Reproducible and GMP compliant automated production of [Ga-68]Ga-DO3A-VS-Cys(40)-Exendin-4 was developed. Exendin-4 comprising methionine amino acid residue was prone to oxidation which was strongly influenced by the elevated temperature, radioactivity amount, and precursor concentration. The suppression of the oxidative radiolysis was achieved by addition of ethanol, dihydroxybenzoic acid and ascorbic acid to the reaction buffer as well as by optimizing heating temperature. The non-decay corrected radiochemical yield was 43 +/- 2% with radiochemical purity of over 90% wherein the individual impurity signals in HPLC chromatogram did not exceed 5%. Automated production and quality control methods were established for paving the pathway for broader clinical use of [Ga-68]Ga-DO3A-VS-Cys(40)-Exen

Background: Treatment of hyperinsulinemic hypoglycaemia (HH) is challenging due to the rarity of this condition and the difficulty of differential diagnosis. The aim of this article is to give an overview of the recent literature on the management of adult HH. Methods: A search for reviews, original articles, original case reports between 1995 and 2016 in PubMed using the following keywords: hyperinsulinemic hypoglycaemia, insulinoma, nesidioblastosis, gastric bypass, autoimmune hypoglycaemia, hyperinsulinism, treatment was performed. Results: One hundred and forty articles were selected and analysed focusing on the most recent treatments of HH. Conclusions: New approaches to treatment of HH are available including mini-invasive surgical techniques and alternative local–regional ablative therapy for benign insulinoma and everolimus for malignant insulinoma. A correct differential diagnosis is of paramount importance to avoid unnecessary surgical operations and to implement the appropriate treatment mainly in the uncommon forms of HH, such as nesidioblastosis and autoimmune hypoglycaemia.

Insulinoma (INS), which causes clinical signs associated with hypoglycaemia, is the most common pancreatic neuroendocrine tumour (pNET) of dogs and humans. Ten tot fifteen percent of human INS metastasise to regional lymph nodes and the liver, and these are referred to as ‘malignant INS’. Surgical excision of malignant INS is rarely complete and malignant INS generally respond poorly to traditional chemotherapeutic agent regimens. Therefore, recurrence is likely, leading to decreased survival times in affected individuals. In the dog, the biological course of INS resembles that of malignant INS in humans, since >95% of these canine tumours metastasise. In the dog, as in humans, surgery along with optional post-operative medical therapy, remains the recommended approach when possible. However, the prognosis for canine INS is still poor, because primary INS is frequently inoperable and/or micrometastases are missed during surgery. Therefore, novel approaches are needed to improve diagnosis, therapy and prognosis for both canine and human INS. Comparative oncology aims to utilise spontaneous tumours in pet animals as sophisticated models for the study of human cancer biology and therapy. Since the release of the canine genome in 2005, cancer in dogs has been repeatedly emphasised as an excellent model for humans. Naturally-occurring cancer in dogs and humans share similarities in histology, tumour biology, and response to conventional therapies. Regarding the close resemblance to human malignant INS, canine INS forms an interesting study model for human INS. Novel targets for human and canine INS therapy may be identified by uncovering the pathways underlying tumourigenesis of canine INS. The aims of this study were to: 1.Develop a novel surgical technique for resection of canine insulinomas and abdominal lymph node metastases; 2.Establish reliable prognostic biomarkers for canine insulinomas that facilitate optimal patient management; 3.Identify novel druggable tar

Background: A 29 year old female who previously underwent a pylorus preserving pancreaticoduodenectomy for an insulinoma 9 months previously presented with a biliary stricture causing obstructive jaundice. Attempts to traverse the stricture radiologically were unsuccessful. The stricture could not be reached with a paediatric colonoscope and she was considered for surgical revision of the hepaticojejunostomy. Prior to this, one final attempt at endoscopic revision of the hepaticojejunostomy was made. Endoscopic methods: Upsizing of the PTC tract with a 12Fr catheter by interventional radiology allowed insertion of a cholangioscope percutaneously to the level of the anastomosis. A single balloon enteroscope was advanced retrograde to the enteric side of the anastomosis. The exact position of the bilioenteric anastomosis was identified by transillumination from the cholangioscope. The sharp end of an ERCP wire was introduced through the cholangioscope and used to perforate the membrane covering the anastomosis under direct vision from the enteroscope. A covered SEMS was introduced over the wire through the PTC sheath and deployed across the stricture under endoscopic vision. Follow up cholangiogram at 1 week confirms ongoing patency of the stent and the external drain was removed. Follow up at 1 month revealed no clinical signs or symptoms of biliary obstruction. Clinical implications: This technique allowed the patient to undergo an endoscopic procedure as a day case which re-established biliary drainage and avoided major revisional surgery.

Background: Several radiometal-labeled, exendin-based tracers that target glucagon-like peptide-1 receptors (GLP-1R) have been intensively explored for beta cell imaging. The main obstacle has been the high uptake of tracer in the kidneys. This study aimed to develop a novel GLP1-R-specific tracer, with fluorine-18 attached to exendin-4, to label beta cells for clinical imaging with PET (positron emission tomography). We hypothesized that this tracer would undergo reduced kidney uptake. F-18-labeled [Nle(14), Lys(40)] exendin-4 analog ([F-18] exendin-4) was produced via Cu-catalyzed click chemistry. The biodistribution of [F-18] exendin-4 was assessed with ex vivo organ.-counting and in vivo PET imaging. We also tested the in vivo stability of the radiotracer. The localization of F-18 radioactivity in rat and human pancreatic tissue sections was investigated with autoradiography. Receptor specificity was assessed with unlabeled exendin-3. Islet labeling was confirmed with immunohistochemistry. The doses of radiation in humans were estimated based on biodistribution results in rats. Results: [F-18] exendin-4 was synthesized with high yield and high specific activity. Results showed specific, sustained [F-18] exendin-4 uptake in pancreatic islets. In contrast to previous studies that tested radiometal-labeled exendin-based tracers, we observed rapid renal clearance of [F-18] exendin-4. Conclusions: [F-18] exendin-4 showed promise as a tracer for clinical imaging of pancreatic beta cells, due to its high specific uptake in native beta cells and its concomitant low kidney radioactivity uptake.

Background: A 29 year old female who previously underwent a pylorus preserving pancreaticoduodenectomy for an insulinoma 9 months previously presented with a biliary stricture causing obstructive jaundice. Attempts to traverse the stricture radiologically were unsuccessful. The stricture could not be reached with a paediatric colonoscope and she was considered for surgical revision of the hepaticojejunostomy. Prior to this, one final attempt at endoscopic revision of the hepaticojejunostomy was made. Endoscopic methods: Upsizing of the PTC tract with a 12Fr catheter by interventional radiology allowed insertion of a cholangioscope percutaneously to the level of the anastomosis. A single balloon enteroscope was advanced retrograde to the enteric side of the anastomosis. The exact position of the bilioenteric anastomosis was identified by transillumination from the cholangioscope. The sharp end of an ERCP wire was introduced through the cholangioscope and used to perforate the membrane covering the anastomosis under direct vision from the enteroscope. A covered SEMS was introduced over the wire through the PTC sheath and deployed across the stricture under endoscopic vision. Follow up cholangiogram at 1 week confirms ongoing patency of the stent and the external drain was removed. Follow up at 1 month revealed no clinical signs or symptoms of biliary obstruction. Clinical implications: This technique allowed the patient to undergo an endoscopic procedure as a day case which re-established biliary drainage and avoided major revisional surgery.

We investigated the relationship between the results of the octreotide test and somatostatin receptor (SSTR) 2 expression in insulinoma patients, to evaluate the usefulness of this test for predicting SSTR2 expression in insulinomas in Japanese patients. Five females and one male were included in the study. All patients underwent the octreotide test before the surgery carried out to resect the tumor, and histopathological examination of the resected tumor was performed by a single experienced pathologist. SSTR2 expression was evaluated by the SSTR2 immunohistochemistry scoring system. Insulinoma was clinically diagnosed and surgically resected in all six patients. In the octreotide test, suppression of insulin secretion was sufficient after loading in patients 1-4 and 6. In patient 5, however, the suppression of insulin secretion was insufficient, which resulted in severe hypoglycemia with endogenous relative hyperinsulinemia after the octreotide loading. The histopathological findings revealed SSTR2 expression in the insulinomas of patients 1-4 and 6, but not in the insulinoma of patient 5. In conclusion, improvement of hyperinsulinemic hypoglycemia by octreotide in Japanese insulinoma patients was associated with SSTR2 expression in the tumor. Our results suggest that the octreotide test could be useful for predicting SSTR2 expression in the tumor.

type:Original Article, identifier:http://igakkai.kms-igakkai.com/wp/wp-content/uploads/1983en/9(1)35-38.1983.pdf

Insulinomas are the most common pancreatic neuroendocrine tumors and are typically small and benign. Giant pancreatic insulinomas are rare pancreatic tumors. We report a 67 year old man who presented with signs and symptoms of hypoglycemia. Subsequent laboratory and radiologic studies established the diagnosis of a 13.5 cm insulinoma. The patient underwent a pancreatoduodenectomy. Despite the size, neither local invasion nor metastatic disease was identified on pathological evaluation. In addition to describing the clinical presentation and operative findings, localization and management options of insulinomas are reviewed., Los insulinomas son los tumores neuroendocrinos pancreáticos más frecuentes y típicamente son benignos y pequeños. Los insulinomas gigantes de páncreas son tumores raros. Reportamos el caso de un paciente varón de 67 años, quien presentaba síntomas y signos de hipoglicemia. Subsecuentes estudios de laboratorio y radiológicos establecieron el diagnóstico de un insulinoma de 13,5 cm. Fue sometido a pancreaticoduodenectomía. A pesar del tamaño, en la evaluación patológica no se identificó invasión local ni metástasis. Además de la descripción de la presentación clínica y los hallazgos operatorios, se realiza una revisión de las opciones para la localización y manejo de los insulinomas.

We investigated the relationship between the results of the octreotide test and somatostatin receptor (SSTR) 2 expression in insulinoma patients, to evaluate the usefulness of this test for predicting SSTR2 expression in insulinomas in Japanese patients. Five females and one male were included in the study. All patients underwent the octreotide test before the surgery carried out to resect the tumor, and histopathological examination of the resected tumor was performed by a single experienced pathologist. SSTR2 expression was evaluated by the SSTR2 immunohistochemistry scoring system. Insulinoma was clinically diagnosed and surgically resected in all six patients. In the octreotide test, suppression of insulin secretion was sufficient after loading in patients 1-4 and 6. In patient 5, however, the suppression of insulin secretion was insufficient, which resulted in severe hypoglycemia with endogenous relative hyperinsulinemia after the octreotide loading. The histopathological findings revealed SSTR2 expression in the insulinomas of patients 1-4 and 6, but not in the insulinoma of patient 5. In conclusion, improvement of hyperinsulinemic hypoglycemia by octreotide in Japanese insulinoma patients was associated with SSTR2 expression in the tumor. Our results suggest that the octreotide test could be useful for predicting SSTR2 expression in the tumor.

Insulinoma is a rare pancreatic endocrine tumour with an incidence of 4 per million population per year and is typically sporadic, solitary and less than 2 cms in diameter. Fewer than 5% of insulinomas are larger than 3 cms and are more likely to be malignant. Here we report a case of insulinoma in a female patient aged 57 years with a rare presentation of recurrent attacks of seizures, syncope and sweating along with episodes of hypoglycemia since 5 years. CT scan localized the tumour to the head of the pancreas and histopathology proved the diagnosis.

Insulinomas are pancreatic islet tumors that inappropriately secrete insulin, producing hypoglycemia. Exome and targeted sequencing revealed that 14 of 43 insulinomas harbored the identical somatic mutation in the DNA-binding zinc finger of the transcription factor Yin Yang 1 (YY1). Chromatin immunoprecipitation sequencing (ChIP-Seq) showed that this T372R substitution changes the DNA motif bound by YY1. Global analysis of gene expression demonstrated distinct clustering of tumors with and without YY1(T372R) mutations. Genes showing large increases in expression in YY1(T372R) tumors included ADCY1 (an adenylyl cyclase) and CACNA2D2 (a Ca2+ channel); both are expressed at very low levels in normal beta-cells and show mutation-specific YY1 binding sites. Both gene products are involved in key pathways regulating insulin secretion. Expression of these genes in rat INS-1 cells demonstrated markedly increased insulin secretion. These findings indicate that YY1(T372R) mutations are neomorphic, resulting in constitutive activation of cAMP and Ca2+ signaling pathways involved in insulin secretion.

Diabetes epidemic is underway. Beta cell dysfunction (BCF) and loss of beta cell mass (BCM) are known to be key events in its progression. Currently, there are no reliable techniques to estimate or follow the loss of BCM, in vivo. Non-invasive imaging and quantification of the whole BCM in the pancreas, therefore, has a great potential for understanding the progression of diabetes and the scope for early diagnosis for Type 2 diabetes. Glucagon-like peptide-1 receptor (GLP-1R) is known to be selectively expressed on the pancreatic beta cells and overexpressed on the insulinoma, a pancreatic neuroendocrine tumor (PNET). Therefore, this receptor is considered to be a selective imaging biomarker for the beta cells and the insulinoma. Exendin-4 is a naturally occurring analog of GLP-1 peptide. It binds and activates GLP-1R with same the potency and engages in the insulin synthesis, with a longer biological half-life. In this thesis, Exendin-4 precursor, DO3A-VS-Cys40-Exendin-4 labeled with [68Ga], [68Ga]Ga-DO3A-VS-Cys40-Exendin-4 ([68Ga]Exendin-4), was evaluated in different species models, namely, immune deficient nude mice, rats, pigs, non-human primate (NHP), and clinically in one insulinoma patient by positron emission tomography (PET), for its potential in beta cell imaging and its quantification as well as for visualizing the insulinoma. From internal dosimetry, the possible number of repetitive [68Ga]Exendin-4-PET/CT scans was estimated. Pancreatic uptake and insulinoma tumor uptake of [68Ga]Exendin-4 were confirmed to be mediated by the specific binding to the GLP-1R. Pancreatic GLP-1R could be visualized and semi-quantified, for diabetic studies, except in rats. Nonetheless, we found conflicting results regarding the GLP-1R being a selective imaging biomarker for the beta cells. PET/CT scan of the patient with [68Ga]Exendin-4 has proven to be more sensitive than the clinical neuroendocrine tracer, [11C]5-HTP, as it could reveal small metastatic tumors in liver.

Diabetes epidemic is underway. Beta cell dysfunction (BCF) and loss of beta cell mass (BCM) are known to be key events in its progression. Currently, there are no reliable techniques to estimate or follow the loss of BCM, in vivo. Non-invasive imaging and quantification of the whole BCM in the pancreas, therefore, has a great potential for understanding the progression of diabetes and the scope for early diagnosis for Type 2 diabetes. Glucagon-like peptide-1 receptor (GLP-1R) is known to be selectively expressed on the pancreatic beta cells and overexpressed on the insulinoma, a pancreatic neuroendocrine tumor (PNET). Therefore, this receptor is considered to be a selective imaging biomarker for the beta cells and the insulinoma. Exendin-4 is a naturally occurring analog of GLP-1 peptide. It binds and activates GLP-1R with same the potency and engages in the insulin synthesis, with a longer biological half-life. In this thesis, Exendin-4 precursor, DO3A-VS-Cys40-Exendin-4 labeled with [68Ga], [68Ga]Ga-DO3A-VS-Cys40-Exendin-4 ([68Ga]Exendin-4), was evaluated in different species models, namely, immune deficient nude mice, rats, pigs, non-human primate (NHP), and clinically in one insulinoma patient by positron emission tomography (PET), for its potential in beta cell imaging and its quantification as well as for visualizing the insulinoma. From internal dosimetry, the possible number of repetitive [68Ga]Exendin-4-PET/CT scans was estimated. Pancreatic uptake and insulinoma tumor uptake of [68Ga]Exendin-4 were confirmed to be mediated by the specific binding to the GLP-1R. Pancreatic GLP-1R could be visualized and semi-quantified, for diabetic studies, except in rats. Nonetheless, we found conflicting results regarding the GLP-1R being a selective imaging biomarker for the beta cells. PET/CT scan of the patient with [68Ga]Exendin-4 has proven to be more sensitive than the clinical neuroendocrine tracer, [11C]5-HTP, as it could reveal small metastatic tumors in liver.

Diabetes epidemic is underway. Beta cell dysfunction (BCF) and loss of beta cell mass (BCM) are known to be key events in its progression. Currently, there are no reliable techniques to estimate or follow the loss of BCM, in vivo. Non-invasive imaging and quantification of the whole BCM in the pancreas, therefore, has a great potential for understanding the progression of diabetes and the scope for early diagnosis for Type 2 diabetes. Glucagon-like peptide-1 receptor (GLP-1R) is known to be selectively expressed on the pancreatic beta cells and overexpressed on the insulinoma, a pancreatic neuroendocrine tumor (PNET). Therefore, this receptor is considered to be a selective imaging biomarker for the beta cells and the insulinoma. Exendin-4 is a naturally occurring analog of GLP-1 peptide. It binds and activates GLP-1R with same the potency and engages in the insulin synthesis, with a longer biological half-life. In this thesis, Exendin-4 precursor, DO3A-VS-Cys40-Exendin-4 labeled with [68Ga], [68Ga]Ga-DO3A-VS-Cys40-Exendin-4 ([68Ga]Exendin-4), was evaluated in different species models, namely, immune deficient nude mice, rats, pigs, non-human primate (NHP), and clinically in one insulinoma patient by positron emission tomography (PET), for its potential in beta cell imaging and its quantification as well as for visualizing the insulinoma. From internal dosimetry, the possible number of repetitive [68Ga]Exendin-4-PET/CT scans was estimated. Pancreatic uptake and insulinoma tumor uptake of [68Ga]Exendin-4 were confirmed to be mediated by the specific binding to the GLP-1R. Pancreatic GLP-1R could be visualized and semi-quantified, for diabetic studies, except in rats. Nonetheless, we found conflicting results regarding the GLP-1R being a selective imaging biomarker for the beta cells. PET/CT scan of the patient with [68Ga]Exendin-4 has proven to be more sensitive than the clinical neuroendocrine tracer, [11C]5-HTP, as it could reveal small metastatic tumors in liver.