Department of Nuclear Medicine, Technische Universität München, Ismaningerstr. 22, 81675 Munich, Germany.
Eur J Nucl Med Mol Imaging. 2012 May;39(5):846-51. doi: 10.1007/s00259-012-2061-8. Epub 2012 Jan 26.
Despite recent advances in clinical imaging modalities, differentiation of pancreatic masses remains difficult. Here, we tested the diagnostic accuracy of molecular-based imaging including 3'-deoxy-3'-[(18)F]fluorothymidine (FLT) positron emission tomography (PET) and [(18)F]fluorodeoxyglucose (FDG) PET/CT in patients with suspected pancreatic masses scheduled to undergo surgery.
A total of 46 patients with pancreatic tumours suspicious for malignancy and scheduled for resective surgery were recruited prospectively. In 41 patients, FLT PET and FDG PET/CT scans were performed. A diagnostic CT performed on a routine basis was available in 31 patients. FLT PET and FDG PET/CT emission images were acquired according to standard protocols. Tracer uptake in the tumour [FDG and FLT standardized uptake value (SUV)] was quantified by the region of interest (ROI) technique. For FDG PET/CT analysis, correct ROI placement was ensured via side-by-side reading of corresponding CT images.
Of 41 patients, 33 had malignancy, whereas 8 patients had benign disease. Visual analysis of FDG and FLT PET resulted in sensitivity values of 91% (30/33) and 70% (23/33), respectively. Corresponding specificities were 50% (4/8) for FDG PET and 75% (6/8) for FLT PET. In the subgroup of patients with contrast-enhanced CT (n = 31), sensitivities were 96% (PET/CT), 88% (CT alone), 92% (FDG PET) and 72% (FLT PET), respectively. Mean FLT uptake in all malignant tumours was 3.0 (range SUV(max) 1.1-6.5; mean FDG SUV(max) 7.9, range 3.3-17.8; p < 0.001).
For differentiation of pancreatic tumours, FDG PET and FDG PET/CT showed a higher sensitivity but lower specificity than FLT PET. Interestingly, visual analysis of FLT PET led to two false-positive findings by misinterpreting physiological bowel uptake as pathological FLT uptake in the pancreas. Due to the limited number of patients, the clinical value of adding FLT PET to the diagnostic workup of pancreatic tumours remains to be determined.
尽管临床影像模式有了最近的进展，但是胰腺肿块的鉴别仍然具有挑战性。在这里，我们测试了包括 3'-脱氧-3'-[[18]F]氟代胸苷（FLT）正电子发射断层扫描（PET）和[[18]F]氟脱氧葡萄糖（FDG）PET/CT 在内的分子成像在疑似胰腺肿块患者中的诊断准确性，这些患者计划接受手术。
共招募了 46 名疑似恶性胰腺肿瘤并计划进行切除术的患者进行前瞻性研究。在 41 名患者中，进行了 FLT PET 和 FDG PET/CT 扫描。31 名患者可获得常规诊断 CT。根据标准方案采集 FLT PET 和 FDG PET/CT 发射图像。通过感兴趣区域（ROI）技术定量肿瘤中的示踪剂摄取[FDG 和 FLT 标准化摄取值（SUV）]。对于 FDG PET/CT 分析，通过并排阅读相应的 CT 图像来确保正确的 ROI 放置。
在 41 名患者中，33 名患有恶性肿瘤，而 8 名患有良性疾病。FDG 和 FLT PET 的视觉分析结果分别为 91%（30/33）和 70%（23/33）的敏感性。相应的特异性分别为 50%（4/8）用于 FDG PET 和 75%（6/8）用于 FLT PET。在增强 CT（n = 31）的患者亚组中，敏感性分别为 96%（PET/CT）、88%（CT 单独）、92%（FDG PET）和 72%（FLT PET）。所有恶性肿瘤的平均 FLT 摄取量为 3.0（SUV(max) 范围 1.1-6.5；平均 FDG SUV(max) 7.9，范围 3.3-17.8；p <0.001）。
对于胰腺肿瘤的鉴别，FDG PET 和 FDG PET/CT 显示出较高的敏感性，但特异性较低，而 FLT PET 则较低。有趣的是，FLT PET 的视觉分析导致了两个假阳性发现，因为错误地将生理肠摄取解释为胰腺中的病理性 FLT 摄取。由于患者数量有限，因此将 FLT PET 添加到胰腺肿瘤的诊断评估中的临床价值仍有待确定。
