Nuklearmedizinische Klinik und Poliklinik, Klinikum rechts der Isar der Technischen Universität München, Ismaninger Str. 22, 81675, Munich, Germany.
Eur J Nucl Med Mol Imaging. 2011 Nov;38(11):2005-13. doi: 10.1007/s00259-011-1875-0. Epub 2011 Jul 27.
Neuroendocrine tumours are frequently located in the upper abdomen and especially in the pancreas. Imaging of the abdomen with somatostatin analogs such as (68)Ga-DOTA-Phe(1)-Tyr(3)-octreotide (DOTATOC) is a standard approach for imaging neuroendocrine cancer, but is still challenging due to physiological and technical considerations in this area. Therefore, the aim of this study was to further investigate the origin of (68)Ga-DOTATOC findings in the pancreas.
Forty-three consecutive patients with neuroendocrine tumours were examined by (68)Ga-DOTATOC positron emission tomography (PET)/CT for staging or restaging. As imaging of the upper abdomen is frequently affected by breathing artefacts, PET and CT data were analysed for misalignment and rearranged if necessary. Any noticeable uptake in the pancreas was described. Tracer uptake in the head of the pancreas and the liver was measured by means of maximum and average standard uptake value (SUV(max), SUV(av)). The reference standards (malignant versus benign) for correlation with PET findings were clinical and radiological follow-up (mean follow-up time 14 months) (n = 37) or histological confirmation (n = 6).
In 23 of 43 studies (54%) misalignment between PET and CT data was found with a mean value of 1.4 cm. Visual assessment demonstrated that 20 of 43 scans (46.6%) showed no uptake in the head of the pancreas. Of 43 scans, 23 (53.4%) showed noticeable uptake with focal pattern in the head of the pancreas in 10 scans and irregular pattern in 13 scans. Follow-up indicated malignant pancreatic lesions in three patients. The pancreatic head to liver SUV(av) ratios in these patients ranged from 1.62 to 6.85, whereas in cases of uptake without known malignancy ratios ranged from 0.56 to 1.19. Considering SUV(max), the ratio ranged from 3.24 to 9.1 and from 0.84 to 1.47, respectively. No statistically significant difference was noted between uptake in the head of the pancreas and the liver in patients without malignant pancreatic tumours (p > 0.05).
(68)Ga-DOTATOC uptake in the head of the pancreas is a common finding in patients undergoing (68)Ga-DOTATOC PET/CT. However, this finding most likely represents a physiological condition, especially if the uptake in the pancreatic head is similar to the uptake in the liver (uptake ratio head to liver SUV(av) < 1.4). Therefore, quantification is recommended to avoid false-positive diagnosis. Misalignment due to respiratory motion must always be taken into account.
神经内分泌肿瘤常位于上腹部，特别是胰腺。使用生长抑素类似物（如 68Ga-DOTA-Phe1-Tyr3-octreotide [DOTATOC]）对腹部进行成像，是一种用于成像神经内分泌癌的标准方法，但由于该区域的生理和技术因素，仍然具有挑战性。因此，本研究的目的是进一步研究胰腺中 68Ga-DOTATOC 发现的起源。
对 43 例神经内分泌肿瘤患者进行 68Ga-DOTATOC 正电子发射断层扫描（PET）/CT 分期或重新分期检查。由于上腹部成像经常受到呼吸伪影的影响，因此需要对 PET 和 CT 数据进行分析和重新排列，如果有必要的话。描述了胰腺中任何明显的摄取情况。通过最大和平均标准摄取值（SUV(max)，SUV(av)）测量胰腺头部和肝脏中的示踪剂摄取。与 PET 结果相关的参考标准（恶性与良性）是临床和影像学随访（平均随访时间 14 个月）（n = 37）或组织学确认（n = 6）。
在 43 项研究中的 23 项（54%）中发现了 PET 和 CT 数据之间的错位，平均值为 1.4 厘米。视觉评估显示，43 项扫描中有 20 项（46.6%）在胰腺头部没有摄取。在 43 项扫描中，23 项（53.4%）在胰腺头部有明显摄取，10 项扫描中呈局灶性模式，13 项扫描中呈不规则模式。随访显示 3 例患者有恶性胰腺病变。这些患者的胰腺头部至肝脏 SUV(av)比值范围为 1.62 至 6.85，而在无恶性肿瘤摄取的情况下，比值范围为 0.56 至 1.19。考虑到 SUV(max)，比值范围为 3.24 至 9.1 和 0.84 至 1.47。在无恶性胰腺肿瘤的患者中，胰腺头部和肝脏的摄取无统计学差异（p > 0.05）。
68Ga-DOTATOC 在胰腺头部的摄取是接受 68Ga-DOTATOC PET/CT 检查的患者的常见发现。然而，这种发现很可能代表一种生理状态，特别是如果胰腺头部的摄取与肝脏相似（摄取比头部到肝脏 SUV(av) < 1.4）。因此，建议进行定量分析以避免假阳性诊断。必须始终考虑由于呼吸运动引起的错位。
