Zhu H, Wang F, Guo X Y, Li L Q, Duan D B, Liu Z B, Yang Z
Department of Nuclear Medicine, Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Peking University Cancer Hospital & Institute, Beijing 100142, China.
College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
Beijing Da Xue Xue Bao Yi Xue Ban. 2018 Apr 18;50(2):364-367.
To provide useful information for the further production and application of this novel radio-nuclide for potential clinical application.
Te (p,n) I nuclide reaction was used for the I production. Firstly, the target material, TeO (200 mg) and Al2O3 (30 mg) mixture, were compressed into the round platinum based solid target by tablet device. HM-20 medical cyclotron was applied to irradiate the solid target slice for 6-10 h with helium and water cooling. Then, the radiated solid target was placed for 12 h (overnight) to decay the radioactive impurity; finally, I was be purified by dry distillation using 1 mL/min nitrogen for about 6 hours and radiochemical separation methods. Micro-PET imaging studies were performed to investigate the metabolism properties and thyroid imaging ability of I.After 740 kBq I was injected intravenously into the tail vein of the normal mice, the animals were imaged with micro-PET and infused with CT. The micro-PET/CT infusion imaging revealed actual state I's metabolism in the mice.
It was been successfully applied for 200 mg TeO plating by the tablet device on the surface of platinum. It showed smooth, dense surface and without obviously pits and cracks. The enriched Te target was irradiated for 6 to 10 hours at about 12.0 MeV with 20 μA current on HM-20 cyclotron. Then 370-1 110 MBq I could be produced on the solid target after irradiation and 370-740 MBq high specific activity could be collected afterdry distillation separation and radio-chemical purification.I product was finally dissolved in 0.01 mol/L NaOH for the future distribution. The gamma spectrum of the produced I-solution showed that radionuclide purity was over 80.0%. The micro-PET imaging of I in the normal mice exhibited the thyroid and stomach accumulations and kidney metabolism, the bladder could also be clearly visible, which was in accordance with what was previously reported. To the best of our knowledge, it was the first production of I report in China.
In this study, the preparation of TeO solid target was successfully carried out by using the tablet device. After irradiation of the TeO solid target and radio-chemical purification, we successfully produced 370-740 MBq high specific activity I by a cyclotron for biomedical application, and micro-PET imaging of I in normal mice exhibited the thyroid accumulations. Also, slight uptake in stomach were also monitored with almost nonuptake in other organs in the micro-PET imaging. The production of I is expected to provide a new solid target radionuclide for the scientific research and potential clinical application of our country.
为这种新型放射性核素的进一步生产和潜在临床应用提供有用信息。
采用碲（p，n）碘核素反应来生产碘。首先，将靶材料碲酸（200mg）和氧化铝（30mg）的混合物通过压片装置压制成圆形铂基固体靶。应用HM - 20医用回旋加速器，在氦气和水冷条件下对固体靶片辐照6 - 10小时。然后，将辐照后的固体靶放置12小时（过夜）以使放射性杂质衰变；最后，通过以1mL/分钟的氮气进行约6小时的干馏及放射化学分离方法对碘进行纯化。进行微型正电子发射断层显像（Micro - PET）成像研究以考察碘的代谢特性和甲状腺显像能力。在将740kBq碘静脉注射到正常小鼠尾静脉后，用微型正电子发射断层显像仪对动物进行成像并注入计算机断层扫描（CT）。微型正电子发射断层显像/计算机断层扫描（Micro - PET/CT）融合成像显示了碘在小鼠体内的实际代谢情况。
通过压片装置成功地在铂表面镀上了200mg碲酸。其表面光滑、致密，无明显凹坑和裂纹。在HM - 20回旋加速器上，以约12.0MeV的能量、20μA的电流对富集碲靶辐照6至10小时。辐照后固体靶上可产生370 - 1110MBq碘，经过干馏分离和放射化学纯化后可收集到370 - 740MBq的高比活度碘。最终将碘产品溶解于0.01mol/L氢氧化钠中以备后续使用。所制备的碘溶液的γ能谱表明放射性核素纯度超过80.0%。正常小鼠体内碘的微型正电子发射断层显像显示甲状腺和胃有聚集，肾脏有代谢，膀胱也清晰可见，这与先前报道一致。据我们所知，这是国内首次关于碘生产的报道。
本研究中，通过压片装置成功制备了碲酸固体靶。在对碲酸固体靶进行辐照和放射化学纯化后，我们利用回旋加速器成功生产出了370 - 至740MBq高比活度的碘用于生物医学应用，正常小鼠体内碘的微型正电子发射断层显像显示有甲状腺聚集。此外，微型正电子发射断层显像还监测到胃有轻微摄取，而其他器官几乎无摄取。碘的生产有望为我国的科研和潜在临床应用提供一种新的固体靶放射性核素。
