胰岛素瘤是最常见的功能性胰腺神经内分泌肿瘤，这些肿瘤通过高胰岛素血症诱导低血糖。由于延迟诊断，胰岛素瘤引起的低血糖可能导致癫痫、昏迷或死亡。唯一的治愈方法是手术切除。为了进行根治性手术切除胰岛素瘤，术前定位至关重要。然而，使用传统影像方法如计算机断层扫描（CT）和磁共振成像（MRI）定位胰岛素瘤通常具有挑战性。虽然在这些情况下进行内镜超声（EUS）细针穿刺和选择性动脉钙激动试验可以反映肿瘤的内分泌特性，但这些方法具有侵入性并且需要依赖操作者的技术。此外，生长抑素受体（SSTR）靶向成像由于SSTR类型2表达低，对于检测胰岛素瘤的敏感性相对较低。因此，迫切需要开发一种非侵入性诊断技术，具有特异性用于检测胰岛素瘤。因此，胰高血糖样肽-1受体靶向成像最近出现并引起广泛关注。最近，我们开发了一种新型的与聚乙二醇偶联的18F标记的exendin-4探针，[18F]FB(ePEG12)12-exendin-4（18F-exendin-4），用于正电子发射断层扫描（PET）成像。在这里，我们报告了一例胰岛素瘤病例，18F-exendin-4 PET/CT非侵入性地提供了定位所需的重要信息。这是一位58岁男性的病例，急性低血糖症状已持续10年；然而，由于难以通过常规影像与辅助脾区分开来，术前未能确定胰岛素瘤的诊断。此外，患者要求避免包括EUS在内的侵入性诊断程序。18F-exendin-4 PET/CT显示胰尾有显著吸收，脾脏未见明显吸收；因此，进行了胰尾局部切除手术。通过组织病理检查证实了胰岛素瘤的诊断。这是首次用18F-exendin-4 PET/CT诊断胰岛素瘤的病例报告。在这种情况下，PET信息通过胰腺切除来实现根治。18F-exendin-4 PET/CT可能作为一种有用的非侵入性临床工具用于胰岛素瘤定位。版权所有©2023 Sakaki、Murakami、Fujimoto、Shimizu、Miyake、Otani、Kiyobayashi、Okada、Fujimoto、Hakata、Yamauchi、Shimada、Shimizu、Nagai、Nakamoto和Inagaki。

Insulinomas are the most common functioning pancreatic neuroendocrine neoplasms, and these tumors induce hypoglycemia due to hyperinsulinemia. Hypoglycemia caused by insulinomas can cause seizures, coma or death due to the delayed diagnosis. The only curative treatment is surgical resection. To perform curative surgical resection of insulinomas, preoperative localization is crucial. However, localization of insulinomas is often challenging using conventional imaging methods such as computed tomography (CT) and magnetic resonance imaging. Although endoscopic ultrasound (EUS) fine-needle aspiration and selective arterial calcium stimulation test, which can reflect the endocrine character of the tumor, are performed in such cases, these modalities are invasive and require operator-dependent techniques. Additionally, somatostatin receptor (SSTR)-targeted imaging has a relatively low sensitivity for detecting insulinomas due to its low SSTR type 2 expression. Thus, there is an urgent need for developing a noninvasive diagnostic technique which is specific for detecting insulinomas. Consequently, glucagon-like peptide-1 receptor-targeted imaging has recently emerged and gained a wide interest. Recently, we have developed a novel 18F-labeled exendin-4-based probe conjugated with polyethylene glycol, [18F]FB(ePEG12)12-exendin-4 (18F-exendin-4), for positron emission tomography (PET) imaging. Here we report a case of insulinoma in which 18F-exendin-4 PET/CT noninvasively provided critical information for localization.This is a case of a 58-year-old male with symptomatic hypoglycemia for 10 years; however, a preoperative diagnosis of insulinoma was not established due to the difficulty in differentiating it from an accessory spleen using conventional imaging. Moreover, the patient requested to avoid invasive diagnostic procedures including EUS. 18F-exendin-4 PET/CT revealed significant uptakes in the pancreatic tail whereas no apparent uptakes were observed in the spleen; thus, curative laparoscopic enucleation of the pancreatic tail was performed. The diagnosis of insulinoma was confirmed via histopathological examination. This is the first case report of insulinoma diagnosed using 18F-exendin-4 PET/CT.In this case, PET information led to curative resection through enucleation of the pancreas. 18F-exendin-4 PET/CT may serve as a useful noninvasive clinical tool for insulinoma localization.Copyright © 2023 Sakaki, Murakami, Fujimoto, Shimizu, Miyake, Otani, Kiyobayashi, Okada, Fujimoto, Hakata, Yamauchi, Shimada, Shimizu, Nagai, Nakamoto and Inagaki.