MedStar Clinical Research Center, MedStar Health Research Institute, 6525 Belcrest Road #700, Hyattsville, MD, 20782, USA.
Nuclear Medicine Research, MedStar Washington Hospital Center, 110 Irving Street NW, Washington, DC, 20010, USA.
Endocrine. 2018 Oct;62(1):57-63. doi: 10.1007/s12020-018-1636-y. Epub 2018 May 24.
The detection of recurrent disease in differentiated thyroid cancer (DTC) patients with elevated or rising serum thyroglobulin (Tg) levels and multiple negative conventional imaging studies can be challenging, especially when F-FDG PET/CT scan is also negative. We report a patient and review the literature on the diagnostic use of Tc-sestamibi scans to identify the source of elevated or rising Tg in patients with negative conventional imaging including negative F-FDG PET/CT scans.
A 73-year-old woman was referred for widely-invasive metastatic follicular thyroid cancer with bone metastasis to her left mandible. She had a total thyroidectomy, left mandibular resection, and I therapy of 145 mCi (5.4 GBq) and her subsequent unstimulated serum Tg level was 29 ng/ml (TgAb negative). At six months' follow-up, her stimulated Tg was 527 ng/ml (TSH 188 mIU/L, TgAb negative). All imaging studies performed within the prior 12 months were reported as negative for recurrence or metastasis; this included neck ultrasound, diagnostic radioiodine scan, chest CT and, F-FDG PET/CT. The patient was injected with 24.6 mCi (910 MBq) of Tc-sestamibi intravenously, and whole-body and SPECT/CT images were acquired.
The Tc-sestamibi whole-body posterior image demonstrated abnormal focal uptake in the right posterior calvarium and corresponded to an occipital lytic bone lesion on the SPECT/CT. The patient underwent surgical resection of the skull metastasis, and pathology confirmed metastatic follicular thyroid cancer. Five months post-surgery, the suppressed Tg was markedly reduced and remained stable at ~3.2 ng/ml. With the knowledge of the DTC recurrence location, the two sets of F-FDG images were re-evaluated. The more thorough and targeted interpretation underscored the importance of structured image reporting. The current literature on the utility of Tc-sestamibi scans when radioiodine, F-FDG PET/CT, and other imaging studies are negative is sparse and inconsistent.
Tc-sestamibi may have a role in thyroid cancer localization when physical exam, neck ultrasound, radioiodine scan, chest/abdomen CT, and F-FDG PET/CT does not identify the source of elevated Tg levels in DTC.
对于甲状腺球蛋白（Tg）水平升高或升高且多次阴性常规影像学检查的分化型甲状腺癌（DTC）患者，检测复发性疾病具有挑战性，尤其是当 F-FDG PET/CT 扫描也为阴性时。我们报告了一例患者，并回顾了 Tc- sestamibi 扫描在识别阴性常规影像学检查（包括阴性 F-FDG PET/CT 扫描）包括升高或升高的 Tg 来源中的诊断用途的文献。
一名 73 岁女性因广泛侵袭性滤泡状甲状腺癌伴左侧下颌骨骨转移而就诊。她接受了甲状腺全切除术、左侧下颌骨切除术和 145 mCi（5.4 GBq）的 I 治疗，随后未刺激的血清 Tg 水平为 29 ng/ml（TgAb 阴性）。在 6 个月的随访中，她的刺激 Tg 为 527 ng/ml（TSH 188 mIU/L，TgAb 阴性）。在过去 12 个月内进行的所有影像学检查均报告为无复发或转移；包括颈部超声、诊断性放射性碘扫描、胸部 CT 和 F-FDG PET/CT。患者静脉注射 24.6 mCi（910 MBq）Tc-sestamibi，获得全身和 SPECT/CT 图像。
Tc-sestamibi 全身后图像显示右侧顶骨异常局灶性摄取，并与 SPECT/CT 上的枕骨溶骨性骨病变相对应。患者接受了颅骨转移瘤切除术，病理证实为甲状腺滤泡癌转移。手术后 5 个月，抑制性 Tg 明显降低，稳定在~3.2 ng/ml。根据 DTC 复发部位的知识，重新评估了两组 F-FDG 图像。更彻底和有针对性的解释强调了结构化图像报告的重要性。目前关于放射性碘、F-FDG PET/CT 和其他影像学检查阴性时 Tc-sestamibi 扫描的实用性的文献很少且不一致。
当体格检查、颈部超声、放射性碘扫描、胸部/腹部 CT 和 F-FDG PET/CT 无法确定 DTC 中升高的 Tg 水平的来源时，Tc-sestamibi 可能在甲状腺癌定位中具有作用。
