Copper complex N(4)-ortho-toluyl-2-acetylpyridine thiosemicarbazone - (64Cu)(H2Ac4oT)Cl - internal dosimetry: animal model and human extrapolation

Thiosemicarbazones have attracted great pharmacological interest because of their biological properties, such as cytotoxic activity against multiple strains of human tumors. Due to the excellent properties of 64Cu, the copper complex N(4)-ortho-toluyl-2-acetylpyridine thiosemicarbazone ( (64Cu)(H2Ac4oT)Cl) was developed for tumor detection by positron emission tomography. The radiopharmaceuticals were produced in the nuclear reactor TRIGA-IPR-R1 from CDTN. At the present work, (64Cu)(H2Ac4oT)Cl biokinetic data (evaluated in mice bearing Ehrlich tumor) were treated by MIRD formalism to perform Internal Dosimetry studies. Doses in several organs of mice were determinate, as well as in implanted tumor, for (64Cu)(H2Ac4oT)Cl. Doses results obtained for animal model were extrapolated to humans assuming a similar concentration ratio among various tissues between mouse and human. In the extrapolation, it was used human organ masses from Cristy/Eckerman phantom. Both penetrating and non-penetrating radiation from 64Cu in the tissue were considered in dose calculations. (author)