Preparation of Patient Doses of [177Lu]Lu-DOTATATE and [177Lu]Lu-PSMA-617 with Carrier Added (CA) and No Carrier Added (NCA) 177Lu

Purpose [Lu-177]Lu-DOTATATE and [Lu-177]Lu-PSMA-617 used for targeted radionuclide therapy are very often prepared in the hospital radiopharmacy. The preparation parameters vary depending upon the specific activity of the Lu-177 used. The aim of this study was to develop optimized protocols to be used in the nuclear medicine department for the preparation of patient doses of the above radiopharmaceuticals. Method( 177)Lu (CA and NCA) were used for radiolabeling DOTATATE and PSMA-617. Parameters studied are Lu-177 of different specific activity and different peptide concentrations and two different buffer systems. Paper and thin layer chromatography systems were used for estimating the radiochemical yield as well as radiochemical purity. Solid-phase extraction was used for the purification of the labeled tracers. Results [Lu-177]Lu-DOTATATE was prepared with CA Lu-177 (n = 13) and NCA(177)Lu (n = 6). Four batches each of [Lu-177]Lu-PSMA-617 were prepared using CA and NCA Lu-177. Radiochemical yields > 80% and final product with less than < 1% radiochemical impurity could be obtained in all batches which were used for therapy. Conclusion Robust protocols for the preparation of clinical doses of [Lu-177]Lu-DOTATATE and [Lu-177]Lu-PSMA-617 were developed and used for the preparation of clinical doses. The quality of the SPECT images of both the tracers are consistent with the expected uptake in respective diseases.