Kunte Sophie Carina, Siegmund Thorsten, Tiling Maximilian, Ostermair Lukas, Unterrainer Lena Maria, Theodoropoulou Marily, Reincke Martin, Völter Friederike
Department of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany.
Bayerisches Zentrum für Krebsforschung (BZKF), Partner Site Munich, Munich, Germany.
Front Endocrinol (Lausanne). 2025 May 16;16:1536301. doi: 10.3389/fendo.2025.1536301. eCollection 2025.
Positron-emission-tomography-(PET)/computed-tomography-(CT) using somatostatin-receptor-(SSTR)-binding radioligands is well established in the imaging of neuroendocrine tumors (NETs). SSTRs are expressed in NETs and endocrine and exocrine tissues, e.g. pancreas, where somatostatin binding to SST2 and SST5 inhibits glucagon and insulin secretion. Pancreatic background activity on SSTR-PET varies widely and is increased in up to 45% of cases. High uptake in the can obscure NETs or cause false positives. The determinants of elevated pancreatic activity on SSTR-PET remain unclear, prompting investigation into the association between pancreatic radioligand uptake and diabetic status.
All patients with non-pancreatic NETs undergoing [68Ga]Ga-DOTATOC-PET/CT at LMU clinic with available HbA1c were included. Patients were grouped: without glucose metabolism disorder (HbA1c 4.0-5.6%), prediabetes (HbA1c 5.7-6.4%), type 2 diabetes mellitus. Pancreatic volume and tracer uptake were assessed, with correlation and regression analyses between SSTR expression and HbA1c.
The study included 40 patients (54 scans; n=22: normal glucose metabolism, n=20: prediabetes, n=12: diabetes; n=11: antidiabetic medication (AM)). Patients with normal glucose homeostasis showed increased tracer-uptake than those with impaired glucose metabolism (p=0.033; p=0.009). Correlation analysis revealed a significant negative correlation of HbA1c and SUVmax in patients without AM (r2 = 0.267; p<0.001). Multiple linear regression analysis with AM as a covariate revealed a significant association between HbA1c and SUVmax (r2 = 0.667; CI -0.371 to -0.135; p<0.001), AM was a significant covariate (CI 1.393 to 2.120; p<0.001). The association between HbA1c and SUVmean showed a trend (p=0.061) but no statistical significance.
Our findings indicate a significant association between pancreatic [68Ga]Ga-DOTATOC-uptake and glucose metabolism, suggesting that [68Ga]Ga-DOTATOC-PET/CT sensitivity for detecting pancreatic NETs may be affected by individual glucose homeostasis.
使用与生长抑素受体（SSTR）结合的放射性配体的正电子发射断层扫描（PET）/计算机断层扫描（CT）在神经内分泌肿瘤（NETs）成像中已得到广泛应用。SSTRs在NETs以及内分泌和外分泌组织中表达，例如胰腺，生长抑素与SST2和SST5结合可抑制胰高血糖素和胰岛素分泌。SSTR-PET上的胰腺背景活性差异很大，高达45%的病例中会升高。胰腺部位的高摄取可能会掩盖NETs或导致假阳性。SSTR-PET上胰腺活性升高的决定因素尚不清楚，这促使人们研究胰腺放射性配体摄取与糖尿病状态之间的关联。
纳入所有在LMU诊所接受[68Ga]Ga-DOTATOC-PET/CT检查且有可用糖化血红蛋白（HbA1c）的非胰腺NETs患者。患者分为：无葡萄糖代谢紊乱（HbA1c 4.0 - 5.6%）、糖尿病前期（HbA1c 5.7 - 6.4%）、2型糖尿病。评估胰腺体积和示踪剂摄取情况，并对SSTR表达与HbA1c进行相关性和回归分析。
该研究纳入40例患者（54次扫描；n = 22：葡萄糖代谢正常，n = 20：糖尿病前期，n = 12：糖尿病；n = 11：使用抗糖尿病药物（AM））。葡萄糖稳态正常的患者示踪剂摄取高于葡萄糖代谢受损的患者（p = 0.033；p = 0.009）。相关性分析显示，未使用AM的患者中，HbA1c与SUVmax呈显著负相关（r2 = 0.267；p < 0.001）。以AM作为协变量的多元线性回归分析显示，HbA1c与SUVmax之间存在显著关联（r2 = 0.667；CI -0.371至-0.135；p < 0.001），AM是一个显著的协变量（CI 1.393至2.120；p < 0.001）。HbA1c与SUVmean之间的关联呈现出一种趋势（p = 0.061），但无统计学意义。
我们的研究结果表明胰腺[68Ga]Ga-DOTATOC摄取与葡萄糖代谢之间存在显著关联，提示[68Ga]Ga-DOTATOC-PET/CT检测胰腺NETs的敏感性可能受个体葡萄糖稳态的影响。
