Prasad Vikas, Sainz-Esteban Aurora, Arsenic Ruza, Plöckinger Ursula, Denecke Timm, Pape Ulrich-Frank, Pascher Andreas, Kühnen Peter, Pavel Marianne, Blankenstein Oliver
Department of Nuclear Medicine, Charité Universitätsmedizin Berlin, Berlin, Germany.
Department of Nuclear Medicine, Hospital Clínico Universitario Valladolid, Valladolid, Spain.
Eur J Nucl Med Mol Imaging. 2016 Aug;43(9):1593-600. doi: 10.1007/s00259-016-3331-7. Epub 2016 Feb 29.
To explore the role of (68)Ga-DOTATATE/DOTATOC PET/CT (SR PET/CT) in patients with suspicion of or histopathologically proven pancreatogenic hyperinsulinaemic hypoglycaemia.
We included 13 patients with histopathologically proven or a high clinical suspicion of pancreatogenic hyperinsulinaemia. All the patients underwent a SR PET/CT scan. The results were correlated with histopathological findings. Normalization of blood glucose levels after resection of the pancreatic lesion, as well as a cytological and/or pathological diagnosis of insulinoma, was considered the diagnostic gold standard for insulinoma. The diagnosis of nesidioblastosis was based on exclusion of an insulinoma and conclusive pathological examination of a segment of the pancreas. Malignant insulinoma was defined as the presence of locoregional or distant metastases.
Based on histopathology, 13 patients were found to have pancreatic hyperinsulinaemia: two patients had malignant insulinoma, eight had nonmetastasized insulinoma, and three had nesidioblastosis. SR PET was positive in 11 of the 13 patients (84.6 %) with a final diagnosis of endogenous pancreatic hypoglycaemia. Histopathological staining confirmed 16 foci of hyperinsulinism (insulin positivity). SR PET detected 14 of the 16 lesions, resulting in a sensitivity of 87 %. One intrapancreatic spleen was falsely diagnosed as insulinoma focus on SR PET, resulting in positive predictive value of 93.3 %. Immunohistochemical staining of somatostatin receptor (SSR) subtype 2a was available in ten specimens: two nesidioblastosis, and seven benign and one malignant insulinoma. Eight out of the ten specimens (80 %) stained strongly to moderately positive. Seven of the eight SSR2a-positive lesions were picked up on SR PET. Based on the results of SR PET/CT, nine patients achieved complete remission of the hypoglycaemic events during follow-up.
This explorative study suggests that SR PET in combination with CT may play a significant role in the detection and management of patients with pancreatogenic hyperinsulinaemic hypoglycaemia. A large proportion of insulinomas express SSR2a, and a larger study is needed to fully assess the diagnostic accuracy of SR PET in patients with insulinoma and nesidioblastosis compared with current localizing studies used in clinical practice.
探讨（68）Ga - DOTATATE/DOTATOC PET/CT（SR PET/CT）在疑似或经组织病理学证实的胰源性高胰岛素血症低血糖患者中的作用。
我们纳入了13例经组织病理学证实或临床高度怀疑胰源性高胰岛素血症的患者。所有患者均接受了SR PET/CT扫描。结果与组织病理学结果相关。胰腺病变切除后血糖水平恢复正常，以及胰岛素瘤的细胞学和/或病理学诊断，被视为胰岛素瘤的诊断金标准。胰岛细胞增生症的诊断基于排除胰岛素瘤以及对胰腺节段的确定性病理检查。恶性胰岛素瘤定义为存在局部或远处转移。
基于组织病理学，13例患者被发现患有胰腺高胰岛素血症：2例为恶性胰岛素瘤，8例为无转移的胰岛素瘤，3例为胰岛细胞增生症。13例最终诊断为内源性胰腺低血糖症的患者中，11例（84.6%）SR PET呈阳性。组织病理学染色证实了16个高胰岛素血症病灶（胰岛素阳性）。SR PET检测到了16个病灶中的14个，灵敏度为87%。1个胰腺内脾脏在SR PET上被误诊为胰岛素瘤病灶，阳性预测值为93.3%。10个标本可进行生长抑素受体（SSR）2a亚型的免疫组化染色：2例胰岛细胞增生症，7例良性和1例恶性胰岛素瘤。10个标本中有8个（80%）染色为强阳性至中度阳性。8个SSR2a阳性病灶中有7个在SR PET上被发现。基于SR PET/CT的结果，9例患者在随访期间低血糖事件完全缓解。
这项探索性研究表明，SR PET联合CT可能在胰源性高胰岛素血症低血糖患者的检测和管理中发挥重要作用。大部分胰岛素瘤表达SSR2a，与当前临床实践中使用的定位研究相比，需要进行更大规模的研究来全面评估SR PET在胰岛素瘤和胰岛细胞增生症患者中的诊断准确性。
