159Gd. Preparation and preliminary evaluation as a potential antitumoral radionuclide

Beta emitting radionuclides, such as 90Y, 153Sm, and 131I, with short half lives and that deliver a higher radiation dose rate, have been used effectively in alleviating bone pain due to metastases, synovectomy, and tumor therapy. The 159Gd is a radionuclide that presents these characteristics; however, its antitumoral potential has yet to be investigated. The present study aims to identify the 159Gd production, structural characterization, and antitumoral activity. To achieve these objectives, GadodiamideR, the most non-ionic dye used in nuclear magnetic resonance imaging, was neutron irradiated for 8 h to obtain 159Gd-Gadodiamide. A final product with high specific activity was obtained, and its structural integrity was determined by Fourier Transformer Infrared Spectroscopy and High Performance Liquid Chromatography methods. Finally, the irradiated product presented good stability and increased to approximately 95 times that of the in vitro cytotoxicity of the gadodiamide against Ehrlich tumor cells. These results suggest that there is a high potential for the use of 159Gd against tumoral cells. (author)