Ma C, Wang X, Shao M, Zhao L, Jiawei X, Wu Z, Wang H
Department of Nuclear Medicine, Xinhua Hospital of Medical School, Shanghai Jiaotong University, Shanghai, Republic of China -
Q J Nucl Med Mol Imaging. 2015 Jun;59(2):220-7. Epub 2014 May 21.
Aim of the present study was to investigate the usefulness of 18F-FDG SPECT/CT in differentiated thyroid cancer (DTC) with elevated serum thyroglobulin (Tg) but negative iodine-131 scan.
This retrospective review of patients with DTC recurrence who had 18F-FDG SPECT/CT and 18F-FDG PET/CT for elevated serum Tg but negative iodine-131 scan (March 2007-October 2012). After total thyroidectomy followed by radioiodine ablation, 86 consecutive patients with elevated Tg levels underwent 18F-FDG SPECT/CT or 18F-FDG PET/CT. Of these, 45 patients had 18F-FDG SPECT/CT, the other 41 patients had 18F-FDG PET/CT 3-4weeks after thyroid hormone withdrawal. The results of 18F-FDG PET/CT and SPECT/CT were correlated with patient follow-up information, which included the results from subsequent imaging modalities such as neck ultrasound, MRI and CT, Tg levels, and histologic examination of surgical specimens. The diagnostic accuracy of the two imaging modalities was evaluated.
In 18F-FDG SPECT/CT scans, 24 (24/45) patients had positive findings, 22 true positive in 24 patients, false positive in 2 patients, true-negative and false-negative in 6, 15 patients, respectively. The overall sensitivity, specificity, and accuracy of 18F-FDG SPECT/CT were 59.5%, 75% and 62.2%, respectively. Twenty six patients had positive findings on 18F-FDG PET/CT scans, 23 true positive in 26 (26/41) patients, false positive in 3 patients, true-negative and false-negative in 9, 6 patients, respectively. The overall sensitivity, specificity, and accuracy of 18F-FDG PET/CT were 79.3%, 81.8% and 78.1%, respectively. Clinical management changed for 13 (29%) of 45 patients by 18F-FDG SPECT/CT, 14 (34%) of 41 patients by 18F-FDG PET/CT including surgery, radiation therapy, or multikinase inhibitor.
Based on the retrospective analysis of 86 patients, 18F-FDG SPECT/CT has lower sensitivity in the diagnosis of DTC recurrence with elevated Tg and negative iodine-131scan to 18F-FDG PET/CT. The clinical application of FDG SPECT/CT is then limited and cannot replace PET/CT.
本研究旨在探讨18F-FDG SPECT/CT在血清甲状腺球蛋白（Tg）升高但碘-131扫描阴性的分化型甲状腺癌（DTC）中的应用价值。
对2007年3月至2012年10月期间因血清Tg升高但碘-131扫描阴性而接受18F-FDG SPECT/CT和18F-FDG PET/CT检查的DTC复发患者进行回顾性分析。在全甲状腺切除并进行放射性碘消融后，86例连续的Tg水平升高的患者接受了18F-FDG SPECT/CT或18F-FDG PET/CT检查。其中，45例患者接受了18F-FDG SPECT/CT检查，另外41例患者在甲状腺激素撤药3 - 4周后接受了18F-FDG PET/CT检查。18F-FDG PET/CT和SPECT/CT的结果与患者的随访信息相关，随访信息包括后续成像检查（如颈部超声、MRI和CT）的结果、Tg水平以及手术标本的组织学检查结果。评估了这两种成像检查方法的诊断准确性。
在18F-FDG SPECT/CT扫描中，24例（24/45）患者有阳性发现，其中24例中有22例为真阳性，2例为假阳性，6例为真阴性，15例为假阴性。18F-FDG SPECT/CT的总体敏感性、特异性和准确性分别为59.5%、75%和62.2%。18F-FDG PET/CT扫描中有26例患者有阳性发现，其中26例（26/41）中有23例为真阳性，3例为假阳性，9例为真阴性，6例为假阴性。18F-FDG PET/CT的总体敏感性、特异性和准确性分别为79.3%、81.8%和78.1%。18F-FDG SPECT/CT使45例患者中的13例（29%）的临床管理发生了改变，18F-FDG PET/CT使41例患者中的14例（34%）的临床管理发生了改变，包括手术、放疗或多激酶抑制剂治疗。
基于对86例患者的回顾性分析，18F-FDG SPECT/CT在诊断Tg升高且碘-131扫描阴性的DTC复发方面的敏感性低于18F-FDG PET/CT。因此，FDG SPECT/CT的临床应用有限，不能替代PET/CT。
