Feasibility of Mass Production of Lu-177 Using Commercial Light Water Reactors

Targeted radionuclide therapy using Lu-177 is mainly used to treat prostate cancer. Although Lu-177 is being produced by research reactors around the world, Lu-177 production has not yet been attempted in Japan. There are two methods of producing Lu-177 in reactors: direct route by the Lu-176(n,γ) reaction and indirect route by the Yb-176(n,γβ) reaction. The direct method using enriched Lu-176 yields a large amount of Lu-177, but its specific activity is approximately as small as 0.5 TBq/mg-Lu at the neutron flux level of commercial light water reactors. On the other hand, the indirect method using enriched Yb-176 yields a smaller amount of Lu-177 than the direct method, but it has a high specific activity of about 4 TBq/mg-Lu that enables the production of no-carrier-added (nca) Lu-177 without the waste problem of Lu-177m (half-life: 160 days). The objective of this study is to produce Lu-177 in PWR while generating electricity. Assuming that the annual demand for Lu-177 in Japan is equivalent to 15,000 castration-resistant prostate cancer patients, one pressurized water reactor could produce the required amount of nca Lu-177 by irradiating 200 g of enriched Yb-176 for 2 weeks × 17 times a year.