Purpose

The novel ¹⁸F-labeled somatostatin receptor (SSTR)-directed radiotracer [¹⁸F]SiTATE demonstrated promising results for the imaging of various SSTR-expressing tumor types. Although thyroid carcinomas (TC) express SSTR, data on [¹⁸F]SiTATE PET/CT imaging in TC are lacking. This study explores the use of [¹⁸F]SiTATE PET/CT in a patient cohort with histologically proven TC.

Methods

As part of a prospective observational study at a single tertiary cancer center, 21 patients with TC (10 medullary (MTC) and 11 differentiated (DTC)) who underwent at least one [¹⁸F]SiTATE PET/CT were included (37 scans in total). Mean SUV_max and SUV_mean of tumoral lesions, mean total-tumor-volume (TTV), and whole-body (WB)-SUV_max and WB-SUV_mean on PET with their standard deviations (SDs) were determined. PET parameters were correlated to clinical parameters including tumor marker levels (thyroglobulin for DTC, calcitonin for MTC).

Results

89 lesions were included in the analysis. Metastases were localized in the bone, lymph nodes, lung, soft tissue, and thyroid bed. Osseous (31 lesions; SUV_max 8.6 ± 8.0; SUV_mean 5.8 ± 5.4) and nodal (37 lesions; SUV_max 8.7 ± 7.8; SUV_mean 5.7 ± 5.4) metastases showed the highest uptake. The MTC disease burden on PET significantly correlated with the calcitonin tumor marker level (e.g., TTV: r = 0.771, r² = 0.594, p = 0.002). For DTC, no such correlation was present.

Conclusion

Our data demonstrate high feasibility of [¹⁸F]SiTATE PET/CT in a small cohort of patients with MTC and DTC. The use of [¹⁸F]SiTATE may overcome logistical disadvantages of ⁶⁸Ga-based tracers and facilitate SSTR-targeted PET/CT imaging of thyroid carcinoma.

中文翻译：

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使用新型 SSTR 靶向肽 [18F]SiTATE 对分化型甲状腺癌和髓样甲状腺癌进行 PET/CT 成像 – 初步临床经验

 目的

新型 ¹⁸F 标记的生长抑素受体 （SSTR） 定向放射性示踪剂 [¹⁸F]SiTATE 在各种表达 SSTR 的肿瘤类型的成像方面显示出有希望的结果。虽然甲状腺癌 （TC） 表达 SSTR，但缺乏 TC 中 [¹⁸F]SiTATE PET/CT 成像的数据。本研究探讨了 [¹⁸F]SiTATE PET/CT 在经组织学证实的 TC 患者队列中的应用。

 方法

作为在单个三级癌症中心进行的前瞻性观察研究的一部分，纳入了 21 名接受了至少一项 [¹⁸F]SiTATE PET/CT 的 TC 患者 （10 例髓质 （MTC） 和 11 例分化型 （DTC）） （共 37 次扫描）。确定了肿瘤病灶的平均 SUV_max 和 SUV_平均值、平均肿瘤总体积 （TTV） 以及 PET 上的全身 （WB）-SUV_max 和 WB-SUV_平均值及其标准差 （SD）。PET 参数与临床参数相关，包括肿瘤标志物水平 （甲状腺球蛋白用于 DTC，降钙素用于 MTC）。

 结果

分析包括 89 个病灶。转移灶位于骨骼、淋巴结、肺、软组织和甲床。骨性 （31 个病灶;SUV_最大 8.6 ± 8.0;SUV_平均 5.8 ± 5.4）和淋巴结 （37 个病灶;SUV_最大 8.7 ± 7.8;SUV_平均 5.7 ± 5.4） 转移显示摄取最高。PET 上的 MTC 疾病负荷与降钙素肿瘤标志物水平显著相关 （例如，TTV： r = 0.771，r² = 0.594，p = 0.002）。 对于 DTC，不存在这种相关性。

 结论

我们的数据表明 [¹⁸F]SiTATE PET/CT 在一小群 MTC 和 DTC 患者中具有高度的可行性。使用 [¹⁸F]SiTATE 可以克服 ⁶⁸种基于 Ga的示踪剂的物流劣势，并促进甲状腺癌的 SSTR 靶向 PET/CT 成像。