Quantitative GLP-1 Receptor Imaging Correlated to ex Vivo Distribution of In-111-exendin

Study Overview
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Brief Summary
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The main goal is to study the correlation of pancreatic uptake of In-111-DTPA-exendin-4 (measured by ex vivo counting) with the beta cell mass determined in the pancreatic specimens obtained after surgery.

Detailed Description
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In order to fully characterize the highly promising tracer In-111-DTPA-exendin-4 in humans, quantitative SPECT imaging will be correlated to the ex vivo tracer distribution in patients undergoing pancreatectomy or a Whipple procedure. In vivo imaging will be combined with post-pancreatectomy (micro)autoradiography, measurement of In-111-DTPA-exendin-4 concentrations in the pancreas using a gamma counter and morphometric determination of the actual beta cell mass. By this means, the relation between tracer uptake and beta cell mass in non-diabetic patients and T2D patients will be established. These highly relevant data will allow the improvement of the interpretation of clinical quantitative SPECT data in subsequent studies in patients with T1D and T2D. In addition, high uptake has been observed in the duodenum/pyloric area in patients in an ongoing study. At this point in time, it remains unclear which cells are responsible for this uptake. It would be of great interest to identify the GLP-1R positive cells in order to better understand the physiological actions of GLP-1 agonists.

Official Title
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Quantitative GLP-1 Receptor Imaging Correlated to ex Vivo Distribution of In-111-exendin

Conditions
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Diabetes Mellitus

Intervention / Treatment
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* Radiation: indium-111-exendin SPECT/CT


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Scheduled for partial or complete pancreatectomy or Whipple procedure at Radboudumc Exclusion Criteria: Resection that provides insufficient amount of tissue Previous treatment with synthetic Exendin (Exenatide, Byetta®) or Dipeptidyl- Peptidase IV inhibitors Breast feeding Pregnancy or the wish to become pregnant within 6 months Renal disease Liver disease Age < 18 years

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Other
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: Scheduled for (partial) pancreatectomy or Whipple procedure<br>I.v. injection with In-111-DTPA-exendin-4 and SPECT/CT scan | Radiation: indium-111-exendin SPECT/CT<br>* SPECT/CT imaging after injection with In-111-DTPA-exendin-4<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Correlation between the tracer uptake (counts) and beta cell mass (mg) | The primary objective is the correlation between the ex vivo In-111-exendin tracer accumulation in the pancreas (counts) of patients undergoing pancreatectomy or Whipple procedure, and the beta cell mass (mg) in non- diabetic patients and patients with diabetes. | 4 years | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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exendin-4, GLP-1 receptor imaging, SPECT, pancreas, surgery, quantification