Theranostics Center for Molecular Radiotherapy and Precision Oncology, ENETS Center of Excellence, Zentralklinik Bad Berka, Bad Berka, Germany;
Theranostics Center for Molecular Radiotherapy and Precision Oncology, ENETS Center of Excellence, Zentralklinik Bad Berka, Bad Berka, Germany.
J Nucl Med. 2021 Oct;62(10):1391-1397. doi: 10.2967/jnumed.120.258376. Epub 2021 Feb 5.
Tb has decay properties similar to those of Lu but, additionally, emits a substantial number of conversion and Auger electrons. The aim of this study was to apply Tb in a clinical setting and to investigate the feasibility of visualizing the physiologic and tumor biodistributions of Tb-DOTATOC. Tb was shipped from Paul Scherrer Institute, Villigen-PSI, Switzerland, to Zentralklinik Bad Berka, Bad Berka, Germany, where it was used for the radiolabeling of DOTATOC. In 2 separate studies, 596 and 1,300 MBq of Tb-DOTATOC were administered to a 35-y-old male patient with a metastatic, well-differentiated, nonfunctional malignant paraganglioma and a 70-y-old male patient with a metastatic, functional neuroendocrine neoplasm of the pancreatic tail, respectively. Whole-body planar γ-scintigraphy images were acquired over a period of several days for dosimetry calculations. SPECT/CT images were reconstructed using a recently established protocol and visually analyzed. Patients were observed for adverse events after the application of Tb-DOTATOC. The radiolabeling of DOTATOC with Tb was readily achieved with a high radiochemical purity suitable for patient application. Planar images and dosimetry provided the expected time-dependent biodistribution of Tb-DOTATOC in the liver, kidneys, spleen, and urinary bladder. SPECT/CT images were of high quality and visualized even small metastases in bones and liver. The application of Tb-DOTATOC was well tolerated, and no related adverse events were reported. This study demonstrated the feasibility of imaging even small metastases after the injection of relatively low activities of Tb-DOTATOC using γ-scintigraphy and SPECT/CT. On the basis of this essential first step in translating Tb to clinics, further efforts will be directed toward the application of Tb for therapeutic purposes.
铽具有类似于镥的衰变特性，但除此之外，还发射大量的转换电子和俄歇电子。本研究旨在将铽应用于临床，并研究可视化铽-DOTATOC 的生理和肿瘤生物分布的可行性。铽从瑞士保罗谢尔研究所（Villigen-PSI）运送到德国巴特贝雷克的中央诊所（Zentralklinik Bad Berka），在那里用于 DOTATOC 的放射性标记。在 2 项独立的研究中，分别给一名患有转移性、分化良好、无功能的恶性副神经节瘤的 35 岁男性患者和一名患有转移性、功能性胰腺尾部神经内分泌肿瘤的 70 岁男性患者施用了 356 和 1300 MBq 的铽-DOTATOC。为了进行剂量计算，在几天的时间内采集了全身平面γ闪烁成像图像。使用最近建立的协议重建 SPECT/CT 图像，并进行视觉分析。观察患者在施用铽-DOTATOC 后的不良反应。使用 Tb 对 DOTATOC 进行放射性标记很容易实现，放射化学纯度高，适合患者应用。平面图像和剂量学提供了铽-DOTATOC 在肝脏、肾脏、脾脏和膀胱中的预期时间依赖性生物分布。SPECT/CT 图像质量高，甚至可以可视化骨骼和肝脏中的小转移灶。铽-DOTATOC 的应用耐受性良好，未报告与治疗相关的不良事件。本研究表明，使用γ闪烁成像和 SPECT/CT，即使在注射相对低活性的铽-DOTATOC 后，也可以对小转移灶进行成像。在此基础上，将进一步努力将铽应用于治疗目的。
