Target burn-up corrected specific activity of 177Lu produced via 176Lu(n, γ) 177Lu nuclear reactions

Production of 177Lu for Targeted Radionuclide Therapy: Available Options

“…It is worthwhile to point out that an irradiation period equal to t max does not provide the maximum specific activity owing to the transformation of the target material in the nuclear reaction. As reported by Zhernosekov et al [50] , the actual specific activity of 177 Lu is different from the value obtained by dividing the production of the yield of 177 Lu by the mass of the target irradiated, since the actual mass of lutetium present in the system post irradiation is different from the initial mass of the target irradiated owing to target burn-up. During irradiation, 177 Lu absorbs neutron and leads to the formation of 177/ 178 Hf, which results in the accumulation of the 177 / 178 Hf carrier in the target system.…”

“…This is possible because 176 Lu has a very high thermal neutron capture cross section (σ=2090 b, I 0 =1087 b) for formation of 177 Lu. The neutron capture cross section of 176 Lu does not follow the 1/v law, and there is a strong resonance very close to the thermal region [50,54].…”

“…Under this premise, using the simplified Westcott convention is an effective proposition for the calculation of the reaction rate of 176 Lu(n,γ) 177 Lu in which an additional correction of the activation rate as a function of the thermal neutron flux temperature is necessary to account for the non-abeyance of the 1/ Vn law. This is expressed by the factor k [48][49][50]. Following the simplified Westcott convention and taking into the account the target burn-up of 176 Lu as well as 177 Lu atoms during irradiation, the accumulation of 177 Lu can therefore be expressed by a differential equation:…”

“…With increasing the 'k' value, the yield of 177 Lu during neutron irradiation increases. The time of irradiation at which the maximum activity of 177 Lu is achieved is expressed as [50] t max ¼ 1…”

Timing and optimized acquisition parameters for the whole-body imaging of 177Lu-EDTMP toward performing bone pain palliation treatment

“…The radiochemical processing of the irradiated target to obtain 177 LuCl 3 solution used for the preparation of 177 Lu-EDTMP complex, and the assay of 177 Lu activity and its radionuclide purity, were carried out following the procedure reported previously [13,19]. The work was performed by the China Institute of Atomic Energy under good manufacturing practice conditions.…”