Development of generator technologies for therapeutic radionuclides

Rhenium-188 is an isotope of high therapeutic potential for nuclear medicine. That radionuclide belongs to the group of beta-gamma emitters (energy for beta radiation is 2,11 MeV, and for gamma quantum is 155 keV). The β particles (depth in soft tissues about 8mm) can destroy cancer tissues, while γ quantums describe a place where the radionuclide is accumulated. 188Re complexes with different ligands are more often used in radionuclide therapy, especially in oncology therapy. The studies on the use of 188Re complexes with HEDP and DMSA as pain relives in palliative therapy are performed at present. The complexes with peptides and their use in therapy against cancer are also studied. 188Re sterile and pyrogen-free solution placed inside a balloon is used in brachytherapy of coronary vessels. Beta radiation emitted by 188Re slows the collapse of blood vessels after the operation of their restenosis. According to the literature data, about 60% of patients after traditional operation of coronary vessels restenosis, need it again after six months or their need the stent implantation. If after the operation of restenosis, the 188Re therapy was applied, the restenosis was present at only 40% of the patients. Because of short half-life of 188Re, deliveries to remote customers create a huge logistic problem, which can me solved by delivering 188W/188Re generator as source of 188Re. In the first CRP meeting we presented data obtained when sodium acetate has been used as eluent for 188W/188Re generator. In this report we have changed our solvent/elution system towards 0.9% NaCl, which is more friendly from the point of view of the final user. The eluate is received easily by eluting the generator with 0.9% acidified saline solution. Both the generator column and the lead shielding used in standard 99Mo/99mTc generator (fission 99Mo) were applied to make a 188W/188Re generator. Depending on the needs, the elution would be performed few times a day at the place the generator is needed. The received eluate was sterile what give the possibility of its use just straight after the elution. According to the literature the generators could be used for a long time (above 6 months), as the mother radionuclide has a long half-life (T1/2 is 69 days). In our experience the prepared generator has been evaluated for the period of 4 month and no deviations from its regular performance have been observed