Department of Nuclear Medicine, Department of Internal Medicine Medical Research Institute, Pusan National University Hospital, Pusan National University, Busan, South Korea.
Endocr Relat Cancer. 2013 Jul 4;20(4):R203-13. doi: 10.1530/ERC-13-0088. Print 2013 Aug.
The incidence of thyroid cancer in both men and women is increasing faster than that of any other cancer. Although positron emission tomography (PET) using (18)F-fluorodeoxyglucose (FDG) has received much attention, the use of FDG PET for the management of thyroid cancer is limited primarily to postoperative follow-up. However, it might have a role in selected, more aggressive pathologies, and so patients at a high risk of distant metastasis may benefit from PET before surgery. As less FDG-avid thyroid cancers may lower the diagnostic accuracy of PET in preoperative assessment, an understanding of FDG avidity is important for the evaluation of thyroid cancer. FDG avidity has been shown to be associated with tumor size, lymph node metastasis, and glucose transporter expression and differentiation. As PET is commonly used in clinical practice, the detection of incidentalomas by PET is increasing. However, incidentalomas detected by PET have a high risk of malignancy. Clinicians handling cytologically indeterminate nodules face a dilemma regarding a procedure for a definitive diagnosis, usually lobectomy. With 'nondiagnostic (ND)' fine-needle biopsy (FNA), PET has shown a negative predictive value (NPV) of 100%, which indicates that negative uptake in a ND FNA procedure accurately excludes malignancy. With 'atypia of undetermined significance' or 'follicular neoplasm', the sensitivity and NPV of PET are 84 and 88%. PET does not provide additional information for the preoperative assessment of thyroid cancer. However, factors associated with FDG positivity are related to a poor prognosis; therefore, FDG PET scans before surgery may facilitate the prediction of the prognosis of differentiated thyroid cancer.
男性和女性甲状腺癌的发病率增长速度比其他任何癌症都要快。尽管正电子发射断层扫描（PET）使用（18）F-氟代脱氧葡萄糖（FDG）受到了广泛关注，但 FDG PET 在甲状腺癌的管理中的应用主要限于术后随访。然而，它可能在某些侵袭性更强的病变中具有一定作用，因此，患有远处转移高风险的患者可能会受益于手术前的 PET。由于 FDG 摄取较少的甲状腺癌可能会降低 PET 在术前评估中的诊断准确性，因此了解 FDG 摄取对于评估甲状腺癌非常重要。FDG 摄取与肿瘤大小、淋巴结转移以及葡萄糖转运体表达和分化有关。由于 PET 在临床实践中广泛应用，因此通过 PET 检测到的偶发瘤的数量正在增加。然而，PET 检测到的偶发瘤恶性风险较高。处理细胞学不确定结节的临床医生在确定诊断的程序方面面临两难境地，通常是进行叶切除术。对于“非诊断性（ND）”细针活检（FNA），PET 显示出 100%的阴性预测值（NPV），这表明 ND FNA 程序中的阴性摄取准确地排除了恶性肿瘤。对于“意义未明的不典型性”或“滤泡性肿瘤”，PET 的敏感性和 NPV 分别为 84%和 88%。PET 不能为甲状腺癌的术前评估提供额外信息。然而，与 FDG 阳性相关的因素与不良预后有关；因此，在手术前进行 FDG PET 扫描可能有助于预测分化型甲状腺癌的预后。
