PET-CT Scan Method to Monitor Pancreatic B-Cell Loss in Diabetes Mellitus

Summary

The pancreas is an organ that plays major roles in the digestion of food. A part of the pancreas called islet beta-cells produces insulin, which regulates the amount of glucose (a sugar) present in the blood at all times. Type-1 Diabetes Mellitus (T1DM), an autoimmune disorder characterized by destruction of pancreatic islet beta-cells (the cells that produce insulin), affects at least a million individuals in the US alone. In T1DM, a type of white blood cells called T lymphocytes attacks and destroys the pancreatic islet beta-cells, leading to a loss of insulin, an increase in blood glucose, and a dependence on insulin injections for survival. Despite rigorous control of blood sugar, the majority of diabetic patients develop serious complications including retinopathy, nephropathy, neuropathy, microangiopathy and strokes.

Non-invasive methods to monitor pancreatic beta-cell loss associated with type-1 diabetes mellitus (T1DM) could improve early diagnosis, provide tools to measure responsiveness to new therapies, and evaluate the efficiency of pancreatic transplantation and graft survival.

Our goal is to develop a non-invasive PET-CT imaging method based on binding of a molecule (18F-fallypride) for tracking beta-cell loss during the progression of T1DM. In preliminary studies we demonstrated specific binding of 18F-fallypride to D2 receptors in rat pancreatic sections and we demonstrated that the loss of pancreatic beta cells in streptozotocin-treated rats was associated with a corresponding decrease in 18F-fallypride binding to pancreatic sections. A preliminary 18F-fallypride PET-CT study done by a collaborator in Ohio on a healthy volunteer, revealed 18F-fallypride-uptake by the pancreas that was distinguishable from surrounding tissues. Aim-1 of our project will measure the variability of 18F-fallypride PET-scanning of the pancreas in six healthy volunteers scanned twice with an interval of 4-6 weeks. In Aim-2 of our project, we will compare fallypride PET-CT scans of 12 patients with long-standing T1DM (nearly all beta cells destroyed) with 12 age- and sex-matched healthy volunteers. If we are able to distinguish between the two groups, we will in future (a) optimize the method so as to be able to detect a 20-30% loss of beta cells, and (b) perform PET-CT studies in new-onset T1DM patients and in at-risk first degree relatives of T1DM patients.

Conditions

• Type1 Diabetes Mellitus

Interventions

DRUG

18F-fallypride

Single bolus i.v. injection 60 minutes before PET-CT scanning. Maximum activity per single administration 5 mCi; maximum amount of drug per administration \<10 micrograms.

DRUG

18F-fallypride

I.v. bolus maximum activity per single administration 5 mCi; maximum amount of drug per administration \<10 micrograms.

Sponsors & Collaborators

• Juvenile Diabetes Research Foundation

  collaborator OTHER

• University of California, Irvine

  lead OTHER

Principal Investigators

• George K Chandy, MD, PhD · University of California, Irvine

Eligibility

Min Age

18 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2008-02-29

Primary Completion

2008-07-31

Completion

2008-07-31

Countries

• United States

Study Locations