Improved Localization of Insulinomas Using ⁶⁸Ga-NODAGA-Exendin-4 PET/CT

Area of Science:

• Nuclear medicine
• Radiopharmaceuticals
• Diagnostic imaging

Background:

• Accurate localization of insulinomas is critical for successful surgical intervention.
• Conventional imaging techniques like CT, MRI, and 68Ga-DOTA-somatostatin analog (DOTA-SSA) PET/CT have limitations in sensitivity for detecting insulinomas.
• Endoscopic ultrasound is sensitive but invasive, posing risks to patients.

Purpose of the Study:

• To prospectively compare the diagnostic accuracy of 68Ga-NODAGA-exendin-4 (exendin) PET/CT with routine imaging modalities for insulinoma localization.
• To evaluate the image quality and interobserver agreement of exendin PET/CT versus other methods.

Main Methods:

• A prospective multicenter study involving 69 adults with biochemically confirmed hyperinsulinemic hypoglycemia.
• Patients underwent exendin PET/CT and standard imaging (DOTA-SSA PET/CT, CT, MRI, endoscopic ultrasound).
• Image analysis included clinical and expert readings, with quantitative assessment of image quality.

Main Results:

• Exendin PET/CT demonstrated superior diagnostic accuracy (94.4%) compared to DOTA-SSA PET/CT (64.8%), CT/MRI (83.3%), and endoscopic ultrasound (82.8%).
• In 13% of cases, exendin PET/CT was essential for correct diagnosis.
• Exendin PET/CT showed significantly higher insulinoma-to-background and contrast-to-noise ratios, with improved interobserver agreement.

Conclusions:

• 68Ga-NODAGA-exendin-4 (exendin) PET/CT is a highly accurate and superior imaging modality for preoperative localization of benign insulinomas.
• The study provides strong evidence supporting the clinical implementation of exendin PET/CT for insulinoma diagnosis.
• This advanced PET/CT technique enhances diagnostic confidence and potentially improves surgical outcomes.