From the Division of Nuclear Medicine, Department of Radiology, Campinas State University (UNICAMP), São Paulo, Campinas, Brazil.
Division of Endocrinology, Department of Internal Medicine Campinas State University (UNICAMP), São Paulo, Campinas, Brazil.
Clin Nucl Med. 2024 Nov 1;49(11):1004-1013. doi: 10.1097/RLU.0000000000005366. Epub 2024 Sep 11.
TENIS syndrome is characterized by reduced expression of sodium-iodine symporter, rising serum thyroglobulin (Tg) levels, and negative whole-body 131 I scans. In such patients, somatostatin receptor imaging with 68 Ga-DOTATATE PET/CT (somatostatin receptor [SSR] PET/CT) and 18 F-FDG PET/CT (FDG PET/CT) can identify metastases and were compared under 2 conditions: elevated (eTSH) and suppressed (sTSH) TSH serum levels. Potential candidates for peptide receptor radionuclide therapy (PRRNT) were identified in 15 patients prospectively enrolled. All patients underwent 4 examinations. Images were blindly evaluated for differences in SUV max values and lesion detectability. Reference standard consisted of neck ultrasound, CT, MRI, PET/CT, biopsy, and follow-up. Three patients were received PRRNT.
sTSH SSR PET/CT detected a greater number of cervical ( P = 0.0253 and P = 0.0176) and distant LNs ( P = 0.0253 and P = 0.0391) when compared with sTSH FDG PET/CT, respectively, in a per-patient and on a per-lesion based analysis. Likewise, eTSH SSR PET/CT detected a greater number of patients with local recurrences ( P = 0.0455) and distant LN metastases ( P = 0.0143). Per-lesion analysis revealed greater number of cervical and distant LNs ( P = 0.0337 and P = 0.0039, respectively) when compared with eTSH FDG PET/CT. There was no difference in detection of distant metastases by both tracers for lung and bone metastases (κ = 1). Both skeletal and pulmonary lesions were also detected by conventional CT part of FDG or DOTATATE PET/CT scans. TSH stimulation had no additional value in a per-patient analysis for both FDG and DOTATATE PET scans (κ varying from 0.6087 to 1). However, TSH stimulation led to more lesion identifications in DOTATATE PET/CT; most of those metastases were not confirmed by the reference standard leading to a decrease in specificity (84% vs 74%). One of 3 patients submitted to 3 cycles of PRRNT presented with a visual partial response, a 20% reduction in quantitative analyses, and stable disease regarding Tg and TgAb levels.
Patients with TENIS syndrome can be imaged with SSR PET/CT as well as FDG PET/CT with high overall accuracy regardless of TSH levels (86% to 92% and 92% to 85%, respectively, with eTSH and sTSH). SSR PET/CT detected a greater number of locoregional and distant LN metastases than FDG PET/CT with both sTSH and eTSH. One of 3 patients submitted to PRRNT presented a partial response to treatment. Our findings may impact in patient restaging, management, and theranostics strategies with radiolabeled somatostatin analogs.
TENIS 综合征的特征是钠碘同向转运体表达减少、血清甲状腺球蛋白（Tg）水平升高以及全身 131 I 扫描呈阴性。在这些患者中，使用 68 Ga-DOTATATE PET/CT（生长抑素受体 [SSR] PET/CT）和 18 F-FDG PET/CT（FDG PET/CT）进行生长抑素受体成像可以识别转移灶，并在两种情况下进行比较：促甲状腺激素（TSH）升高（eTSH）和抑制（sTSH）。前瞻性纳入了 15 名患者以确定肽受体放射性核素治疗（PRRNT）的潜在候选者。所有患者均进行了 4 次检查。盲法评估 SUV max 值和病灶检出率的差异。参考标准包括颈部超声、CT、MRI、PET/CT、活检和随访。有 3 名患者接受了 PRRNT。
与 sTSH FDG PET/CT 相比，sTSH SSR PET/CT 分别在每位患者和每个病灶的基础上分析时，检测到更多的颈部（P = 0.0253 和 P = 0.0176）和远处淋巴结（P = 0.0253 和 P = 0.0391）。同样，eTSH SSR PET/CT 检测到更多局部复发（P = 0.0455）和远处淋巴结转移（P = 0.0143）的患者。基于病灶的分析显示，与 eTSH FDG PET/CT 相比，颈部和远处淋巴结的数量更多（P = 0.0337 和 P = 0.0039）。两种示踪剂在检测肺部和骨骼远处转移方面无差异（κ = 1）。FDG 或 DOTATATE PET/CT 扫描的常规 CT 部分也可检测到骨骼和肺部病变。对于 FDG 和 DOTATATE PET 扫描，TSH 刺激在每位患者的分析中均无额外价值（κ 值在 0.6087 到 1 之间）。然而，TSH 刺激可在 DOTATATE PET/CT 中检测到更多的病灶；大多数转移灶未被参考标准证实，导致特异性降低（84%对 74%）。接受 3 个周期 PRRNT 的 3 名患者中的 1 名出现部分视觉缓解，定量分析减少 20%，以及 Tg 和 TgAb 水平的稳定疾病。
无论 TSH 水平如何（分别为 eTSH 和 sTSH 时为 86%至 92%和 92%至 85%），TENIS 综合征患者均可使用 SSR PET/CT 和 FDG PET/CT 进行成像，具有很高的整体准确性。SSR PET/CT 检测到更多的局部和远处淋巴结转移，比 FDG PET/CT 更多，无论是在 eTSH 还是 sTSH 时。接受 PRRNT 的 3 名患者中的 1 名对治疗有部分反应。我们的研究结果可能会影响患者的分期、管理和放射性标记生长抑素类似物的治疗策略。
