The identification of neck lymph node (LN) metastases represents a very important issue in the management of patients with differentiated thyroid carcinoma (DTC). To this purpose, in the present study, we used 131I-SPECT/CT as a diagnostic imaging procedure. A consecutive series of 224 DTC patients with ascertained neck radioiodine-avid foci at 131I-SPECT/CT during long-term follow-up was evaluated. All patients had already undergone total thyroidectomy and radioiodine therapy and had been classified as follows: 62 at high risk (H), 64 at low risk (L) and 98 at very low risk (VL). 131I-Whole body scan (WBS) followed by SPECT/CT was performed in all cases. In the 224 patients, 449 neck iodine avid foci were ascertained at SPECT/CT, while 322 were evidenced at WBS in 165/224 patients. WBS classified as residues 263/322 foci and as unclear 59/322 foci; among the former foci SPECT/CT correctly characterized 8 LN metastases and 3 physiologic uptakes and among the latter, it pinpointed 26 LN metastases, 18 residues, and 15 physiologic uptakes. SPECT/CT also classified 127 foci occult at WBS as 59 LN metastases and 68 residues. Globally, SPECT/CT identified 93 LN metastases in 59 patients (26 H, 20 L, 13 VL), while WBS evidenced 34 in 25 cases. All 13 VL patients, T1aN0M0, 5 of whom with LN near sub-mandibular glands, had thyroglobulin undetectable or < 2.5 ng/ml. Globally, SPECT/CT obtained an incremental value than WBS in 45.5% of patients, a more correct patient classification changing therapeutic approach in 30.3% of cases and identified WBS false-positive findings in 8% of cases. 131I-SPECT/CT proved to correctly detect and characterize neck LN metastases in DTC patients in long-term follow-up, improving the performance of planar WBS. SPECT/CT routine use is thus suggested; its role is particularly relevant in patients with WBS inconclusive, VL, T1aN0M0 and with undetectable or very low thyroglobulin levels.

中文翻译：

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¹³¹ I-SPECT / CT研究对分化型甲状腺癌（DTC）患者的颈部淋巴结转移进行长期随访

颈部淋巴结（LN）转移的识别代表分化型甲状腺癌（DTC）患者的治疗中非常重要的问题。为此，在本研究中，我们使用131I-SPECT / CT作为诊断成像程序。评估了连续224例DTC患者，这些患者在长期随访期间均在131I-SPECT / CT上确定了颈部放射性碘-avid病灶。所有患者都已经接受了全甲状腺切除术和放射性碘治疗，并被分类如下：高危（H）62例，低危（L）64例，极低危（VL）98例。在所有情况下均进行131I-全身扫描（WBS），然后进行SPECT / CT。在224例患者中，在SPECT / CT处确定了449例碘碘致病灶，而在165/224例患者中，在WBS处证实了322例碘碘狂犬病灶。WBS分类为残基263/322病灶和不清楚的59/322病灶；在前者SPECT / CT中正确表征了8个LN转移和3个生理摄取，在后者中，它确定了26个LN转移，18个残基和15个生理摄取。SPECT / CT还将WBS的127个潜伏病分类为59个LN转移灶和68个残基。在全球范围内，SPECT / CT在59例患者（26 H，20 L，13 VL）中鉴定出93例LN转移，而WBS证实25例中有34例转移。所有13例VL患者，T1aN0M0，其中5例在下颌下腺附近有LN，均检出甲状腺球蛋白或<2.5 ng / ml。在全球范围内，SPECT / CT在45.5％的患者中获得了比WBS更高的价值，更正确的患者分类改变了30.3％的患者的治疗方法，并在8％的患者中发现了WBS的假阳性结果。在长期随访中，事实证明131I-SPECT / CT可正确检测DTC患者的颈部LN转移并确定其特征，从而改善平面WBS的性能。因此建议SPECT / CT常规使用。它的作用在WBS不确定，VL，T1aN0M0且甲状腺球蛋白水平不可检测或非常低的患者中尤其重要。