Hideya Saeki

Generation of radioisotopes with accelerator neutrons by deuterons

A new system proposed for the generation of radioisotopes with accelerator neutrons by deuterons (GRAND) is described by mainly discussing the production of 99Mo used for nuclear medicine diagnosis. A prototype facility of this system consists of a cyclotron to produce intense accelerator neutrons from the natC(\(d\),\(n\)) reaction with 40 MeV 2 mA deuteron beams, and a sublimation system to separate 99mTc from an irradiated 100MoO3 sample. About 8.1 TBq/week of 99Mo is produced by repeating irradiation on an enriched 100Mo sample (251 g) with accelerator neutrons for two days three times. It meets about 10% of the 99Mo demand in Japan. The characteristic feature of the system lies in its capability to reliably produce a wide variety of high-quality, carrier-free, carrier-added radioisotopes with a minimum level of radioactive waste without using uranium. The system is compact in size, and easy to operate; therefore it could be used worldwide to produce radioisotopes for medical, research, and industrial...

High Thermo-Separation Efficiency of 99mTc from Molten 100MoO3 Samples by Repeated Milking Tests

High thermo-separation efficiencies of about 90 and 70% have been obtained for the first time for 99mTc from molten MoO3 samples containing 99Mo with thicknesses of 4.0 and 8.5 mm, respectively, by repeated milking tests. 99Mo was produced with 100Mo(n,2n)99Mo by using neutrons from 3H(d,n)4He. The thermo-separation efficiency was determined by measuring the 141 keV γ-ray yield of 99mTc within the molten MoO3 samples with a radiation detector as a function of the furnace temperature and time. The diffusion coefficients of 99mTc in the molten MoO3 samples were estimated in order to help understand the high thermo-separation efficiency. The present result solves a long-standing problem of decreasing the separation efficiency of 99mTc from MoO3 while increasing the sample mass or repeating sublimation in thermo-separation, and will bring a major breakthrough to obtain high-quality 99mTc from MoO3 irradiated by accelerator-neutrons (protons) or reactor-neutrons.

First Measurement of the Radionuclide Purity of the Therapeutic Isotope 67Cu Produced by 68Zn(n,x) Reaction Using natC(d,n) Neutrons

We have for the first time studied the radionuclide purity of the therapeutic isotope 67Cu produced by the 68Zn(n,x)67Cu reaction. The neutrons were obtained by the natC(d,n) reaction using 40 MeV ...

Application of 67Cu Produced by 68Zn(n,n′p+d)67Cu to Biodistribution Study in Tumor-Bearing Mice

67Cu produced by the 68Zn(n,n′p+d)67Cu reaction was used for the first time to determine the biodistribution of 67CuCl2 in colorectal tumor-bearing mice. A high uptake of 67Cu was observed in the tumor as well as in the liver and kidney, which are the major organs for copper metabolism. The result showing 67Cu accumulation in the tumor suggests that 67CuCl2 can be a potential radionuclide agent for cancer radiotherapy. It should also encourage further studies on the therapeutic effect on small animals using an increased dose of 67Cu produced by the 68Zn(n,n′p+d)67Cu reaction using presently available intense neutrons.

SPECT Imaging of Mice with 99mTc-Radiopharmaceuticals Obtained from 99Mo Produced by 100Mo(n,2n)99Mo and Fission of 235U

The distribution of 99mTc-radiopharmaceutical in mouse was determined by single photon emission computed tomography (SPECT) for the first time using 99mTc, which was separated by thermochromatograp...

Quality of99mTcO4−from99Mo Produced by100Mo(n,2n)99Mo

The pharmaceutical quality of 99mTc pertechnetate solution obtained from 99Mo, the 100Mo(n,2n) reaction product, was investigated for the first time with an emphasis on the nonradioactive Mo conten...

99Mo Yield Using Large Sample Mass of MoO3 for Sustainable Production of 99Mo

A neutron source from the C(d,n) reaction has the unique capability of producing medical radioisotopes such as 99Mo with a minimum level of radioactive waste. Precise data on the neutron flux are crucial to determine the best conditions for obtaining the maximum yield of 99Mo. The measured yield of 99Mo produced by the 100Mo(n,2n)99Mo reaction from a large sample mass of MoO3 agrees well with the numerical result estimated with the latest neutron data, which are a factor of two larger than the other existing data. This result establishes an important finding for the domestic production of 99Mo: approximately 50% of the demand for 99Mo in Japan could be met using a 100 g 100MoO3 sample mass with a single accelerator of 40 MeV, 2 mA deuteron beams.

Quality of 99m TcO 4 − from 99 Mo Produced by 100 Mo( n ,2 n ) 99 Mo

The pharmaceutical quality of 99mTc pertechnetate solution obtained from 99Mo, the 100Mo(n,2n) reaction product, was investigated for the first time with an emphasis on the nonradioactive Mo conten...