Labelling of Y- and Lu-DOTA-Bioconjugates for Targeted Radionuclide Therapy: A Comparison among Manual, Semiautomated, and Fully Automated Synthesis

In spite of the hazard due to the radiation exposure, preparation of 90Y- and 177Lu-labelled radiopharmaceuticals is still mainly performed using manual procedures. In the present study the performance of a commercial automatic synthesizer based on disposable cassettes for the labelling of 177Lu- and 90Y-DOTA-conjugated biomolecules (namely, DOTATOC and PSMA-617) was evaluated and compared to a manual and a semiautomated approach. The dose exposure of the operators was evaluated as well. More than 300 clinical preparations of both 90Y- and 177Lu-labelled radiopharmaceuticals have been performed using the three different methods. The mean radiochemical yields for 90Y-DOTATOC were %, %, and %, while for 177Lu-DOTATOC they were 98.3%  ± 0.6, 90.8%  ± 8.3, and % when manual, semiautomated, and automated approaches were used, respectively. The mean doses on the whole hands for yttrium-90 preparations were  mSv/GBq,  mSv/GBq, and  mSv/GBq for manual, semiautomated, and automated synthesis, respectively, and for lutetium-177 preparations, they were  mSv/GBq,  mSv/GBq, and  mSv/GBq, respectively. In conclusion, the automated approach guaranteed reliable and reproducible preparations of pharmaceutical grade therapeutic radiopharmaceuticals in a decent RCY. The radiation exposure of the operators remained comparable to the manual approach mainly due to the fact that a dedicated shielding was still not available for the system.