Exendin PET Scan in Delhi — Insulinoma Detection & Localisation | Neurad Diagnostics

Recurrent episodes of low blood sugar (hypoglycemia), particularly after fasting or exercise, can be debilitating and dangerous. When all conventional causes have been excluded, one important diagnosis to consider is an insulinoma — a rare tumor of the pancreatic beta cells. Finding these tiny tumors has historically been one of the more challenging tasks in diagnostic imaging. The Exendin PET Scan, available at Neurad Diagnostics in Delhi, is a highly sensitive imaging tool for insulinoma localization, with reported sensitivity above that of conventional imaging. This guide explains everything you need to know about the 68Ga-Exendin PET/CT scan.

Leading research centers including those affiliated with the Endocrine Society have studied 68Ga-Exendin PET for insulinoma localization, with studies in the Journal of the Endocrine Society confirming sensitivity rates exceeding 95%.

What Is an Exendin PET Scan?

The Exendin PET Scan, formally known as 68Ga-Exendin-4 PET/CT (or 68Ga-NOTA-Exendin-4 PET/CT), is a highly specialized nuclear medicine imaging procedure that uses a Gallium-68 labelled form of Exendin-4 — a peptide that binds selectively to incretin receptors — to detect and localize tumors expressing incretin receptors. These receptors are massively overexpressed (up to 460-fold) on insulinoma cells compared to normal pancreatic tissue, giving the Exendin PET Scan high sensitivity for this notoriously difficult-to-find tumor.

Insulinomas are the most common functional pancreatic neuroendocrine tumor, but they are typically very small (90% are less than 2 cm) and solitary. Their small size makes them invisible or very hard to find on CT, MRI, or even intraoperative ultrasound in a significant proportion of cases. The Exendin PET Scan solves this problem by imaging incretin receptor expression directly — lighting up insulinoma cells with clear contrast against the surrounding pancreatic tissue. At Neurad Diagnostics in Delhi, we offer this highly specialized imaging study, which is available at only a handful of centers across India.

Why Doctors Recommend the Exendin PET Scan

Endocrinologists, gastroenterologists, and endocrine surgeons recommend the Exendin PET Scan primarily for the preoperative localization of insulinomas in patients with confirmed endogenous hyperinsulinemic hypoglycemia. The clinical challenge is significant: without precise preoperative localization, surgeons may need to perform extensive pancreatic exploration or even distal pancreatectomy based on intraoperative findings — increasing surgical risk and morbidity substantially. When the Exendin PET Scan localizes the tumor preoperatively, surgeons can plan a minimally invasive, targeted enucleation of the tumor, preserving pancreatic tissue and reducing surgical risk.

Beyond insulinoma localization, the Exendin PET Scan also has emerging applications in incretin receptor-expressing NETs and in post-bariatric hypoglycemia (where diffuse beta cell hyperplasia may be distinguished from focal insulinoma). It is also being investigated for beta cell mass measurement in diabetes research contexts.

Diseases and Conditions Diagnosed by the Exendin PET Scan

• Insulinoma: Primary indication — a highly sensitive imaging tool for insulinoma localization
• Ectopic Insulinoma: Detects insulinomas in unusual locations (duodenal wall, mesentery) that are often missed on conventional imaging
• Persistent Hyperinsulinemic Hypoglycemia of Infancy (PHHI)/Congenital Hyperinsulinism: Differentiates focal from diffuse disease in children
• Post-bariatric Hypoglycemia: Helps distinguish focal nesidioblastosis from diffuse beta cell hyperplasia
• Other incretin receptor-expressing NETs: Some non-functioning pancreatic NETs and GEP-NETs express incretin receptors
• Gastrinoma: Can show incretin receptor expression

Who Needs an Exendin PET Scan?

Your endocrinologist or surgeon may refer you for an Exendin PET Scan in Delhi if:

• You have biochemically confirmed endogenous hyperinsulinemic hypoglycemia (Whipple’s triad positive)
• CT and/or MRI have failed to localize an insulinoma
• You are being evaluated for pancreatic surgery for hypoglycemia
• You have recurrent hypoglycemia after bariatric surgery
• You have a child with congenital hyperinsulinism requiring focal vs. diffuse disease differentiation
• Your oncologist suspects an incretin receptor-expressing pancreatic neuroendocrine tumor
• Prior imaging was inconclusive for small pancreatic tumor localization

Symptoms That May Lead to an Exendin PET Scan

The clinical presentation of insulinoma is characterized by Whipple’s Triad — the combination of hypoglycemic symptoms, documented low blood glucose, and relief of symptoms with glucose. Specific symptoms include:

• Episodic sweating, trembling, palpitations (autonomic symptoms of hypoglycemia)
• Confusion, cognitive impairment, or behavioral changes during episodes
• Seizures or loss of consciousness
• Headache and visual disturbances
• Hunger and weight gain (due to frequent carbohydrate intake to prevent hypoglycemia)
• Symptoms that occur during fasting or exercise and are relieved by eating
• Episodes documented in the hospital during supervised 72-hour fast test

How the Exendin PET Scan Procedure Works

The Exendin PET Scan works by exploiting the extraordinarily high expression of incretin receptors on insulinoma cells. Exendin-4 is a peptide that binds with extremely high affinity and selectivity to incretin receptors. When labelled with Gallium-68 and injected intravenously, it circulates through the blood and binds to incretin receptor-expressing cells — primarily insulinoma cells and normal beta cells of the pancreas. However, insulinoma cells express incretin receptors at levels far exceeding normal beta cells, creating a clearly detectable focal hotspot on the PET image that corresponds to the tumor location.

A critical procedural consideration is that patients with insulinoma are at risk of hypoglycemia during the scan. To prevent this, a controlled glucose infusion is administered during the procedure. This requires careful medical supervision, which is one reason why this scan should only be performed at centers with expertise in both nuclear medicine and endocrine emergency management — such as Neurad Diagnostics in Delhi.

Preparation Before Your Exendin PET Scan

Due to the risk of hypoglycemia, preparation for the Exendin PET Scan at Neurad Diagnostics in Delhi is more complex than standard PET scans:

• Glucose monitoring: Blood glucose is monitored before, during, and after the procedure
• Glucose infusion: IV glucose (dextrose) infusion may be administered to maintain blood sugar at safe levels throughout the procedure
• Fasting duration: Per physician instructions — typically shorter than standard 72-hour fasting tests
• IV access: Two IV lines may be required — one for tracer injection and one for glucose
• Emergency preparedness: The team is equipped to manage any hypoglycemic episodes
• Documentation: Bring all prior biochemical test results (72-hour fast results, insulin/C-peptide/glucose ratios) and imaging reports
• Prior imaging: Bring CT, MRI, EUS (endoscopic ultrasound) reports if available

Step-by-Step Exendin PET Scan Procedure at Neurad Diagnostics

1. Clinical review: Your full clinical and biochemical history is reviewed by our nuclear medicine and endocrinology team.
2. IV access: Two IV lines are placed — one for tracer, one for glucose monitoring and potential supplementation.
3. Baseline glucose check: Blood glucose is measured and documented.
4. Glucose infusion: Glucose infusion is started if needed for safety.
5. 68Ga-Exendin tracer injection: The tracer is injected intravenously with continuous glucose and vital sign monitoring.
6. Uptake and monitoring period: 45–60 minutes of careful monitoring while the tracer distributes.
7. PET/CT scan: Focused pancreatic and whole-body PET/CT images are acquired.
8. Post-scan monitoring: Blood glucose and vital signs are monitored until stable.
9. Expert reporting: Detailed anatomical localization report prepared for surgical planning.

Advantages of Exendin PET/CT Technology

• High sensitivity for insulinoma: ~95% sensitivity vs. 50-80% for conventional imaging
• Detects sub-centimeter tumors: Finds insulinomas as small as 3-5 mm
• Detects ectopic insulinomas: Finds tumors outside the pancreas that conventional imaging often misses
• Enables minimally invasive surgery: Precise preoperative localization allows targeted enucleation
• Whole-body imaging: Rules out ectopic and metastatic disease simultaneously
• Differentiates focal from diffuse disease: Critical for congenital hyperinsulinism management
• Changes surgical planning in the majority of previously unlocalized cases

Accuracy and Clinical Benefits

The clinical evidence for Exendin PET Scan in insulinoma localization is strong. Landmark studies from European centres have demonstrated sensitivity rates of 90–97% for insulinoma detection — performance that significantly exceeds CT (50–60%), MRI (60–70%), and even endoscopic ultrasound (70–80%). Crucially, Exendin PET performs particularly well for tumors smaller than 1 cm, which are common in insulinoma and precisely where conventional imaging fails most frequently.

In a study of 30 patients with biochemically confirmed insulinoma but negative or equivocal conventional imaging, Exendin PET correctly localized the tumor in 28 of 30 patients — directly enabling minimally invasive targeted surgical resection in the majority of these patients. For patients across India dealing with unexplained hypoglycemia, the Exendin PET Scan at Neurad Diagnostics in Delhi can be an important investigation.

Safety Information

The Exendin PET Scan is safe when performed by experienced teams with appropriate protocols:

• Low radiation dose: Approximately 3–5 mSv effective dose
• Short Ga-68 half-life: Rapid radioactivity clearance
• Hypoglycemia prevention protocol: Glucose monitoring and infusion protocols ensure patient safety throughout
• Expert supervision: Procedure performed under direct medical supervision at Neurad Diagnostics
• AERB compliant facility: Full compliance with Indian radiation safety regulations

Cost of Exendin PET Scan in Delhi NCR

The Exendin PET Scan is a highly specialized procedure available at only a handful of centers in India. At Neurad Diagnostics in Delhi, we offer this scan with all necessary safety protocols. We quote the full applicable rate before you book, with no hidden charges. Please contact us directly for current pricing.

Why Choose Neurad Diagnostics for the Exendin PET Scan in Delhi?

Neurad Diagnostics is one of very few centers in Delhi and India offering the 68Ga-Exendin PET Scan. Our specialized nuclear medicine team has the expertise, protocols, and safety infrastructure required for this complex procedure. We work closely with endocrinologists and endocrine surgeons to ensure that the scan results are translated into surgical planning for each patient. If you are suffering from unexplained hypoglycemia or have been told your insulinoma “cannot be found” on conventional imaging, please speak to your treating doctor about whether an Exendin PET Scan is appropriate for you.

Frequently Asked Questions About the Exendin PET Scan

1. What is an insulinoma?

An insulinoma is a rare, usually benign pancreatic tumor arising from beta cells that secretes excess insulin, causing potentially dangerous episodes of low blood sugar (hypoglycemia). Most insulinomas are small and solitary, making them difficult to find with conventional imaging.

2. Why is the Exendin PET Scan used for insulinoma localisation?

Insulinoma cells express incretin receptors at levels 400-460 times higher than normal tissues. Exendin-4 binds specifically to these receptors, making insulinoma cells light up intensely on PET imaging even when they are very small — detecting tumors that conventional imaging often misses.

3. Can Exendin PET find insulinomas that CT and MRI missed?

Yes. This is one of its primary clinical applications. Studies show Exendin PET localizes insulinomas in 90-97% of cases — including many that are invisible or equivocal on CT, MRI, and endoscopic ultrasound.

4. Is special preparation required for Exendin PET Scan?

Yes. Because patients with insulinoma are at risk of hypoglycemia, special preparation including glucose monitoring and IV glucose infusion protocols is required. Neurad Diagnostics has established safety protocols for this.

5. Can Exendin PET detect malignant insulinomas?

Yes. While most insulinomas are benign, Exendin PET can also detect malignant insulinomas and their metastases, providing whole-body staging information for surgical and oncological planning.

6. Where can I get an Exendin PET Scan in India?

Neurad Diagnostics in Delhi NCR is among the very few centers in India offering the 68Ga-Exendin PET Scan. This scan requires specialized tracer preparation and clinical expertise available at select advanced nuclear medicine centers.

7. How long does the Exendin PET Scan take?

The entire procedure including safety preparation, tracer injection, uptake period, scan, and post-procedure monitoring takes approximately 2-3 hours at Neurad Diagnostics.

8. Is the Exendin PET Scan useful for children with congenital hyperinsulinism?

Yes. The Exendin PET Scan is a key tool in differentiating focal from diffuse congenital hyperinsulinism in children, which is critical for surgical planning — focal disease can be cured by limited resection while diffuse disease requires near-total pancreatectomy.

9. Does the Exendin PET Scan hurt?

The procedure involves IV cannula placement for tracer injection and possibly glucose infusion, which may cause a brief pinch. The scan itself is non-invasive and painless. Our team prioritizes patient comfort throughout.

10. What happens after an insulinoma is found on Exendin PET?

Once the insulinoma is precisely localized on the Exendin PET Scan, the endocrine surgeon can plan a targeted, minimally invasive enucleation of the tumor. This relieves hypoglycemia in most cases.

Conclusion — Book Your Exendin PET Scan at Neurad Diagnostics Delhi

If you or a loved one has been suffering from unexplained hypoglycemia, or if an insulinoma has been biochemically confirmed but cannot be located on conventional imaging, the 68Ga-Exendin PET Scan at Neurad Diagnostics in Delhi may help. This diagnostic tool has made insulinoma localisation, long one of the more difficult problems in endocrine imaging, a more reliable preoperative investigation.