Evaluation of the produced 177Lu-specific activity via direct and indirect methods using Tehran Research Reactor

The present research investigates the feasibility of producing the radionuclide Lutetium-177 (177Lu) at the Tehran research reactor, TRR. 177Lu, with suitable nuclear decay characteristics and good chemical behavior, is an ideal therapeutic radionuclide. Some 177Lu-containing radiopharmaceuticals are currently applied in the treatment of various cancers, and many are under development and being tested in clinical trials in Iran. The radionuclide 177Lu can be produced either directly by the 176Lu (n,γ)177Lu reaction or indirectly by the  reaction. The irradiation yield of 177Lu in both production routes was experimentally determined for 14 days at a thermal neutron flux of 5×1013 cm-2.s-1 and was compared with the theoretical calculations. The effects of higher neutron fluxes and a reduction in 176Yb-enrichment-percentage on the produced activity/specific activity variations were assessed theoretically using MATLAB software. It was found that higher neutron fluxes led to higher activity. However, it does not impact specific activity fall rates two weeks after the end of the bombardment. In addition, a lower enrichment percentage of the target material utilized in the indirect method leads to a faster specific activity fall two weeks after the end of the bombardment.