Kang Ji-Hun, Jung Da-Woon, Pak Kyoung-June, Kim In-Ju, Kim Hak-Jin, Cho Jae-Keun, Shin Sung-Chan, Wang Soo-Geun, Lee Byung-Joo
Department of Otorhinolaryngology-Head and Neck Surgery, Pusan National University School of Medicine, Pusan National University, Busan, South Korea.
Department of Nuclear Medicine, Pusan National University School of Medicine, Pusan National University, Busan, South Korea.
Head Neck. 2018 Jan;40(1):94-102. doi: 10.1002/hed.24967. Epub 2017 Nov 11.
Fluorine-18 fluorodeoxyglucose positron emission tomography/CT ( F-FDG PET/CT) has been widely accepted as an effective method for detecting recurrent papillary thyroid cancer (PTC) in patients with increased serum thyroglobulin (Tg) or Tg antibody (TgAb) levels and negative whole-body scintigraphy (WBS) results. The role of WBS as a diagnostic tool in detecting recurrence has relatively decreased recently. However, only a few studies have examined the usefulness of F-FDG PET/CT for evaluating patients with recurrent PTC, regardless of the WBS results. The purpose of this analysis was to evaluate the diagnostic value and prognostic role of F-FDG PET/CT for patients with recurrent PTC, irrespective of their WBS results.
Sixty-six patients with locoregional recurrent PTC who underwent F-FDG PET/CT and neck CT within 6 months before surgical treatment were included in this retrospective analysis. Imaging findings were compared with postoperative histopathologic results. The diagnostic values of F-FDG PET/CT and neck CT were compared according to the serum Tg and TgAb levels and cervical levels. Each patient's status at the last follow-up was also reviewed, and survival probabilities were estimated using the Kaplan-Meier plot.
The sensitivity, specificity, and diagnostic accuracy of F-FDG PET/CT for the entire patient group were 38.5%, 90.2%, and 58.3%, respectively. The corresponding neck CT values were 55.0%, 85.7%, and 66.7%, respectively. According to the serum Tg and TgAb levels, except for the specificity, most diagnostic values of F-FDG PET/CT were worse than those of the neck CTs, with or without statistical significance. For the high maximum standardized uptake value (SUVmax) group (SUVmax >10) and the low SUVmax group, the median locoregional disease-free survival times were 33.3 months and 81.8 months, respectively (P < .001).
The diagnostic value of F-FDG PET/CT for localizing recurrent lesions was worse than that of the neck CT, irrespective of the WBS results. However, patients with a higher SUVmax showed a significantly worse prognosis than did those with a lower SUVmax. Therefore, we suggest that, in patients with recurrent PTC, F-FDG PET/CT should be considered for prognostication rather than diagnosis.
氟-18氟脱氧葡萄糖正电子发射断层扫描/计算机断层扫描（F-FDG PET/CT）已被广泛认可为检测血清甲状腺球蛋白（Tg）或Tg抗体（TgAb）水平升高且全身闪烁扫描（WBS）结果为阴性的乳头状甲状腺癌（PTC）复发患者的有效方法。近年来，WBS作为检测复发的诊断工具的作用相对下降。然而，仅有少数研究探讨了F-FDG PET/CT在评估复发PTC患者中的应用价值，而未考虑WBS结果。本分析的目的是评估F-FDG PET/CT对复发PTC患者的诊断价值和预后作用，无论其WBS结果如何。
本回顾性分析纳入了66例局部复发PTC患者，这些患者在手术治疗前6个月内接受了F-FDG PET/CT和颈部CT检查。将影像学检查结果与术后组织病理学结果进行比较。根据血清Tg和TgAb水平以及颈部区域，比较F-FDG PET/CT和颈部CT的诊断价值。还对每位患者的末次随访状态进行了评估，并使用Kaplan-Meier曲线估计生存概率。
F-FDG PET/CT对整个患者组的敏感性、特异性和诊断准确性分别为38.5%、90.2%和58.3%。颈部CT的相应值分别为55.0%、85.7%和66.7%。根据血清Tg和TgAb水平，除特异性外，F-FDG PET/CT的大多数诊断价值均低于颈部CT，无论有无统计学意义。对于高最大标准化摄取值（SUVmax）组（SUVmax >10）和低SUVmax组，局部无病生存时间的中位数分别为33.3个月和81.8个月（P <.001）。
无论WBS结果如何，F-FDG PET/CT对定位复发灶的诊断价值均低于颈部CT。然而，SUVmax较高的患者预后明显差于SUVmax较低的患者。因此，我们建议，对于复发PTC患者，F-FDG PET/CT应考虑用于预后评估而非诊断。
