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Diagnostic Performance of Exendin-4 PET/CT in Localizing Insulinomas: A Systematic Review and Meta-analysis.
Acad Radiol · 2025
Last updated 2026-05-28A review of 10 studies found that Exendin-4 PET/CT scans correctly identified insulinoma tumors in 94% of patients and had a 99% accuracy rate in confirming the absence of tumors. Across 573 lesions, the scans detected 85% of tumors and had a 98% success rate in correctly identifying positive cases. However, the scans were less effective in detecting malignant tumors (66% detection rate) and inherited syndrome-associated tumors (68% detection rate) compared to benign tumors (96% detection rate).
AI summary of the abstract below.
| Journal | Acad Radiol, 2025 |
|---|---|
| Citations | 0 |
| Molecules | — |
Abstract
PURPOSE: To systematically evaluate the performance of Exendin-4 PET/CT in localizing insulinomas in patients with endogenous hyperinsulinemic hypoglycemia (EHH).
METHODS: The PubMed and Embase databases were searched through May 2025 to identify relevant articles. The sensitivity and specificity were pooled by using the bivariate random-effects model. The detection rate (DR) and positive predictive value (PPV) were pooled by using the DerSimonian-Laird model. A combination of histopathology, follow-up information, and clinical diagnosis served as the reference standard.
RESULTS: Ten studies were included in the systematic review, of which seven studies were eligible for meta-analysis. On patient-based analysis, six studies involving 518 patients provided data for pooling sensitivity and specificity. The pooled sensitivity and specificity were 94% (95% CI, 91-97%) and 99% (95% CI, 75-100%), respectively. On lesion-based analysis, four studies with 573 lesions provided data for pooling DR and PPV, and the pooled value was 85% (95% CI, 80-89%) and 98% (95% CI, 88-100%), respectively. In 34 (8.1%) of 422 patients from eight studies, among all localization methods, Exendin-4 PET/CT was the sole method that had successfully localized insulinoma lesions. Three studies described DR on specific insulinoma subtypes, with each reporting data for two kinds of subtypes. Exendin-4 PET/CT had a lower DR in malignant [66.4% (93/140) and 50.0% (1/2)] and inherited syndrome-associated (ISA) insulinoma [68.0% (66/97) and 84.6% (11/13)] than in benign insulinoma [95.5% (253/265) and 90.9% (10/11)].
CONCLUSION: Exendin-4 PET/CT showed a high sensitivity and specificity on patient-based analysis and moderately high DR and high PPV on lesion-based analysis in detecting insulinoma in EHH patients. However, careful correlation with conventional imaging modalities is still needed as initial studies showed that Exendin-4 PET/CT had a low DR in the malignant and ISA insulinomas.
Verbatim abstract via PubMed 41033966 ↗