Insulinoma

Hypoglycemia is the term used to refer to lower than normal levels of blood sugar. This study will continue to research the causes of hypoglycemia. Patients involved in the study will be admitted to the Clinical Center of the National Institutes of Health and undergo tests for evaluating blood sugar. Patients will be required to refrain from eating for a set period of time and will undergo blood tests for insulin levels and several other specific diagnostic tests related to insulin secretion. The patients will be under supervision and will be provided with appropriate medical and surgical attention as needed....

To evaluate the potential usefulness of 68Ga/18F-Exendin 4 positron emission tomography/computed tomography (PET/CT) for the diagnosis of primary and metastatic lesions in various GLP-1R-related disease patients.

This clinical research evaluates a new PET/CT imaging agent, \[68Ga\]Ga-HBED-CC-PEG6-exendin-4, for localizing insulinoma, a rare pancreatic tumor that causes severe low blood sugar. Insulinomas are often small and hard to detect with regular CT, ultrasound or standard PET scans. This new tracer targets GLP1R, a protein highly expressed on insulinoma cells, with polyethylene glycol (PEG6) modification to improve tumor uptake and image contrast compared with the earlier similar agent \[68Ga\]Ga-HBED-CC-exendin-4. The investigators plan to enroll 20 adult patients suspected of or confirmed to have insulinoma. All participants will receive two free PET/CT scans within one week: one with the new PEG6-modified tracer and one with the original tracer. The first 3 participants will also get dynamic PET scanning to analyze drug distribution and radiation dose in the human body. Within one month after imaging, patients will undergo surgery or biopsy to get pathological results, which serve as the gold standard to calculate and compare the diagnostic accuracy of the two tracers. All imaging procedures follow standard clinical protocols with safe, low radiation doses within national diagnostic limits. Minor possible risks include slight pain or mild allergic reaction at the injection site; rare side effects related to exendin-4 may occur at a rate below 5%, and the research team has full emergency management measures ready. Participants can withdraw from the study at any time without penalty. All scan fees are covered by the research project, and each subject will receive a formal imaging report for clinical reference. The findings of this trial will help develop a more accurate imaging tool to precisely locate insulinoma and guide surgical treatment.

This purpose of this study is to determine the ability of an 18F-fluoro-L-dihydroxyphenylalanine (18F-DOPA) PET (Positron Emission Tomography) scan to detect a focal lesion of hyperinsulinism and determine the location in patients with congenital hyperinsulinism, Beckwith Wiedemann Syndrome and suspected insulinoma. Safety data will be collected.

Low blood sugars are known to cause brain damage in newborn babies. One of the most common causes of low blood sugars persisting beyond the new born period is a condition called congenital hyperinsulinism (HI). This is a disease whereby the pancreas secretes too much insulin and causes low blood sugars. Twenty to forty percent of these babies will have brain damage. There are two forms of this disease. In one form only a small part of the pancreas makes too much insulin (focal HI) and in the other, the whole pancreas make too much insulin (diffuse HI). Another very similar disease is insulinoma which occurs after birth, but also causes hyperinsulinism. If a surgeon could know which part of the pancreas has the focal lesion he could remove it and cure the patient. The purpose of this study is to investigate whether a new investigational drug called Fluorodopa F 18, when used with a PET scan, can find the focal lesion and guide the surgeon to remove it, thus curing the patient and preventing further brain damage.