Experimental and theoretical study of rhenium radioisotopes production for manufacturing of new compositional radiopharmaceuticals.

Rhenium therapeutic radioisotopes, namely rhenium-186 and 188, are radionuclides that have been used in combination with various ligands to provide different radiopharmaceuticals for the treatment of different diseases for many years. Each of these radioisotopes has its own special attributes, which make it appropriate to destroy special-sized tumors. High energy, long range beta particles in 188Re can give this certainty that large tumors can be eradicated with high efficiency. On the other hand, 186Re with low energy, short range beta particles is adequate item to ruin small tumors with minimum side effects and high yield. Thus, each of these radioisotopes has features that can cover just part of the treatment individually. So we thought accompanying 186Re and 188Re must have the best outcome to treat tumors with various sizes. Irradiating natural rhenium with neutrons has this potential to produce parallel 186Re and 188R together. We are looking for investigating whether the natural rhenium irradiation, in addition the concurrent production of these radioisotopes, gives us the appropriate radioactivity values to produce compositional radiopharmaceuticals? In this research, the experimental and theoretical assessments of 186Re and 188R simultaneous production to reach compositional radiopharmaceutical by natural rhenium irradiation in the Tehran research reactor, as well as the type and amount of produced impurities have been investigated. The results showed that experimental data are in good agreement with theoretical calculations. The maximum relative error in data has been calculated 8%. The results showed that, in the simultaneous production 186Re and 188R via the natural rhenium irradiation method, the amounts of impurities are trivial compared to the main products, and the activities of main products are properly enough to produce compositional radiopharmaceuticals.

Preparation and quality control of ¹77Lu-[tris(1,10-phenanthroline) lutetium(III)] complex for therapy.

The ¹77Lu-[tris(1,10-phenanthroline)lutetium(III)] complex (¹77Lu-PQ3) was prepared successfully with high radiochemical purity (> 99%). Lu-177 chloride was obtained by thermal neutron flux (4 × 10¹³ n.cm⁻².s⁻¹) of natural Lu2(NO3)3 sample, dissolved in acidic media. The radiochemical yield was checked by measuring the radiochemical purity of the (177)Lu-PQ complex by ITLC (10 mM DTPA, pH = 5, as mobile phase). The final complex solution was injected intravenously into wild-type male rats and bio-distribution of the complex was checked for up to 48 hours. The dose limiting organs were shown to be the reticulu-endothelial system. The bio-distribution of the labelled compounds in tumour-bearing animals is under investigation.