Department of Nuclear Medicine, Ludwig-Maximilians-University of Munich, Munich, Germany.
J Nucl Med. 2012 Nov;53(11):1686-92. doi: 10.2967/jnumed.111.101675. Epub 2012 Sep 14.
In patients with suspected but yet not localized neuroendocrine tumors (NETs), early diagnosis or reliable exclusion is crucial for optimal individual prognosis and therapy. Despite recourse to several imaging modalities, the definite diagnosis of NET can be challenging. Therefore, we tested (68)Ga-DOTATATE PET/CT as a tool for improved diagnosis in a cohort of patients with suspected, nonlocalized NET.
(68)Ga-DOTATATE PET/CT recordings were obtained in 104 consecutive patients meeting at least one of the following criteria: clinical suspicion of NET (n = 70), elevated blood levels of tumor markers (n = 49), and image-based suspicion of NET (n = 53). The presence of NET was validated by histopathology (n = 49) or clinical follow-up of 107 ± 59 wk (n = 55).
In 36 of 104 patients (35%), NET was histologically verified, most frequently located in the small bowel (10/36), pancreas (8/36), lung (5/36), and stomach (2/36). Twelve patients had tumors of nonneuroendocrine origin, and 7 patients had benign tumors. (68)Ga-DOTATATE PET/CT identified NET in 29 of the 36 cases and excluded the presence of a NET in 61 of the 68 non-NET patients, indicating a sensitivity of 81% and specificity of 90%. The PET/CT gave a false-positive result in 7 patients and a false-negative in another 7 patients, indicating positive and negative predictive values of 81% and 90%, respectively, and an accuracy of 87%. Chromogranin A levels were significantly higher in both PET-positive patients (1,841 vs. 342 ng/mL; P < 0.05) and patients with verified NET (2,214 vs. 524 ng/mL; P < 0.05).
In patients with suspected NETs due to clinical symptoms, elevated levels of tumor markers, or indeterminate tumors suggestive of NET, (68)Ga-DOTATATE PET/CT is highly accurate, thus supporting its use in clinical routine diagnostics.
在疑似但尚未定位的神经内分泌肿瘤（NET）患者中，早期诊断或可靠排除对于最佳个体预后和治疗至关重要。尽管采用了多种影像学方法，NET 的明确诊断仍具有挑战性。因此，我们测试了（68）Ga-DOTATATE PET/CT 作为提高疑似非局限性 NET 患者诊断的工具。
104 例符合以下至少一项标准的连续患者进行了（68）Ga-DOTATATE PET/CT 记录：NET 的临床疑似（n=70）、肿瘤标志物血液水平升高（n=49）和基于影像学的 NET 疑似（n=53）。NET 的存在通过组织病理学（n=49）或 107±59 周的临床随访（n=55）得到验证。
36 例患者（35%）的 NET 通过组织学证实，最常见的部位是小肠（10/36）、胰腺（8/36）、肺（5/36）和胃（2/36）。12 例患者的肿瘤为非神经内分泌起源，7 例患者为良性肿瘤。（68）Ga-DOTATATE PET/CT 在 36 例中的 29 例中识别出 NET，并在 68 例非 NET 患者中的 61 例中排除 NET 的存在，表明敏感性为 81%，特异性为 90%。PET/CT 在 7 例患者中给出假阳性结果，在另外 7 例患者中给出假阴性结果，分别表明阳性和阴性预测值为 81%和 90%，准确率为 87%。在 PET 阳性患者（1841 vs. 342 ng/mL；P<0.05）和经证实的 NET 患者（2214 vs. 524 ng/mL；P<0.05）中，嗜铬粒蛋白 A 水平明显升高。
对于因临床症状、肿瘤标志物水平升高或提示 NET 的不确定肿瘤而疑似 NET 的患者，（68）Ga-DOTATATE PET/CT 具有很高的准确性，因此支持其在临床常规诊断中的应用。
