Stefano Riga1, Gianfranco Cicoria2, Davide Pancaldi3, Federico Zagni3, Sara Vichi4, Michele Dassenno5, Luca Mora6, Filippo Lodi6, Maria Pia Morigi5, Mario Marengo3. 1. Medical Physics Department, University Hospital, S. Orsola-Malpighi, Bologna, Italy. Electronic address: stefano.riga@studio.unibo.it. 2. Medical Physics Department, Azienda Ospedaliero-Universitaria di Modena, Modena, Italy. 3. Medical Physics Department, University Hospital, S. Orsola-Malpighi, Bologna, Italy. 4. Nuclear Engineering Laboratory of Montecuccolino, University of Bologna, Bologna, Italy. 5. Department of Physics and Astronomy, University of Bologna, Bologna, Italy. 6. PET Radiopharmacy Unit, University Hospital S. Orsola-Malpighi, Bologna, Italy.
Abstract
PURPOSE: In recent years the use of 68Ga (t1/2 = 67.84 min, β+: 88.88%) for the labelling of different PET radiopharmaceuticals has significantly increased. This work aims to evaluate the feasibility of the production of 68Ga via the 68Zn(p,n)68Ga reaction by proton irradiation of an enriched zinc solution, using a biomedical cyclotron, in order to satisfy its increasing demand. METHODS: Irradiations of 1.7 Msolution of 68Zn(NO3)2 in 0.2 N HNO3 were conducted with a GE PETtrace cyclotron using a slightly modified version of the liquid target used for the production of fluorine-18. The proton beam energy was degraded to 12 MeV, in order to minimize the production of 67Ga through the68Zn(p,2n)67Ga reaction. The product's activity was measured using a calibrated activity meter and a High Purity Germanium gamma-ray detector. RESULTS: The saturation yield of68Ga amounts to (330 ± 20) MBq/µA, corresponding to a produced activity of68Ga at the EOB of (4.3 ± 0.3) GBq in a typical production run at 46 µA for 32 min. The radionuclidic purity of the68Ga in the final product, after the separation, is within the limits of the European Pharmacopoeia (>99.9%) up to 3 h after the EOB. Radiochemical separation up to a yield not lower than 75% was obtained using an automated purification module. The enriched material recovery efficiency resulted higher than 80-90%. CONCLUSIONS: In summary, this approach provides clinically relevant amounts of68Ga by cyclotron irradiation of a liquid target, as a competitive alternative to the current production through the68Ge/68Ga generators.
PURPOSE: In recent years the use of 68Ga (t1/2 = 67.84 min, β+: 88.88%) for the labelling of different PET radiopharmaceuticals has significantly increased. This work aims to evaluate the feasibility of the production of 68Ga via the 68Zn(p,n)68Ga reaction by proton irradiation of an enriched zinc solution, using a biomedical cyclotron, in order to satisfy its increasing demand. METHODS: Irradiations of 1.7 Msolution of 68Zn(NO3)2 in 0.2 N HNO3 were conducted with a GE PETtrace cyclotron using a slightly modified version of the liquid target used for the production of fluorine-18. The proton beam energy was degraded to 12 MeV, in order to minimize the production of 67Ga through the68Zn(p,2n)67Ga reaction. The product's activity was measured using a calibrated activity meter and a High Purity Germanium gamma-ray detector. RESULTS: The saturation yield of68Ga amounts to (330 ± 20) MBq/µA, corresponding to a produced activity of68Ga at the EOB of (4.3 ± 0.3) GBq in a typical production run at 46 µA for 32 min. The radionuclidic purity of the68Ga in the final product, after the separation, is within the limits of the European Pharmacopoeia (>99.9%) up to 3 h after the EOB. Radiochemical separation up to a yield not lower than 75% was obtained using an automated purification module. The enriched material recovery efficiency resulted higher than 80-90%. CONCLUSIONS: In summary, this approach provides clinically relevant amounts of68Ga by cyclotron irradiation of a liquid target, as a competitive alternative to the current production through the68Ge/68Ga generators.
Authors: Melissa E Rodnick; Carina Sollert; Daniela Stark; Mara Clark; Andrew Katsifis; Brian G Hockley; D Christian Parr; Jens Frigell; Bradford D Henderson; Monica Abghari-Gerst; Morand R Piert; Michael J Fulham; Stefan Eberl; Katherine Gagnon; Peter J H Scott Journal: EJNMMI Radiopharm Chem Date: 2020-11-12