Production of 161Tb Radionuclide

Abstract

Targeted radionuclide therapy (TRT)，the use of radiopharmaceuticals to target and irradiate tumour cells，has become an important method for cancer treatment. The radiolanthanide Lutetium-177 (177Lu) is a medium-energy beta radionuclide with a suitable electron energy range for treatment of small tumors，and has been widely used in clinical targeted radionuclide therapy. The radiolanthanide terbium-161 (161Tb) isotope has similar decay properties，biochemical properties，and in vivo characteristics to 177Lu，and it releases more Auger electrons and internal conversion electrons than 177Lu. It has been proposed，and preclinically demonstrated，that 161Tb is a better alternative to 177Lu for the treatment of small prostate cancer lesions. According to the conferences and published articles on nuclear medicine in recent years，more and more attention has been paid to the preparation of 161Tb nuclides and the development of its labeled drugs in the field of radiopharmaceuticals. However，there is no mature production process for 161Tb internationally，which has seriously hindered the clinical research of 161Tb-labeled drugs. Currently，there are two main methods for the preparation research of 161Tb. One is to produce 161Tb through an accelerator，and the other is to produce carrier-free 161Tb using a high-throughput reactor or a fission neutron source via the reaction 160Gd(n，γ)161Gd→161Tb. Commercial production of 161Tb using an accelerator is very difficult. The most common method internationally is to irradiate enriched 160Gd2O3 target material with a reactor or a fission neutron source to produce carrier-free 161Tb. According to the investigation，there are several research institutes or companies at home and abroad are carrying out relevant research on the preparation of 161Tb. Chengdu Gaotong Isotope Co.，Ltd. (CNNC) used enriched 160Gd2O3 target material irradiated by a reactor with neutron flux of about 1-2×1014 n·cm−2·s−1 to separate a large amount of irradiated 160Gd by a two-column method to prepare no carrier-added 161TbCl3 nuclide solutions. Chengdu Gaotong Isotope Co.，Ltd. has carried out many experiments on the preparation of 161Tb from 160Gd target material enriched. After separation and purification，the radionuclide purity，radiochemical purity and activity of 161TbCl3 nuclide solution were detected by high purity germanium gamma spectrometer，activity meter and other instruments and equipment. The results showed that the radionuclide solution of 161TbCl3 with radionuclide purity greater than or equal to 99.9%，radiochemical purity greater than 99% and chemical purity was obtained after the separation and purification of 161Gd target material enriched by irradiation in the reactor.

Keywords

• trt
• cancer
• 177lu
• 161tb