Production Cross-Section Measurements for Terbium Radionuclides of Medical Interest Produced in Tantalum Targets Irradiated by 0.3 to 1.7 GeV Protons and Corresponding Thick Target Yield Calculations

Abstract

This work presents the production cross-sections of Ce, Tb and Dy radionuclides produced by 300 MeV to 1.7 GeV proton-induced spallation reactions in thin tantalum targets as well as the related Thick Target production Yield (TTY) values and ratios. The motivation is to optimise the production of terbium radionuclides for medical applications and to find out at which energy the purity of the collection by mass separation would be highest. For that purpose, activation experiments were performed using the COSY synchrotron at FZ Jülich utilising the stacked-foils technique and γ spectrometry with high-purity germanium detectors. The Al-27(p,x)Na-24 reaction has been used as monitor reaction. All experimental data have been systematically compared with the existing literature.

Terbium radionuclides for theranostic applications in nuclear medicine: from atom to bedside

“…The production of terbium-149 remains the most challenging, hindering its availability. For preclinical research, terbium-149 has primarily been produced by high energy proton induced spallation of tantalum targets followed by mass separation 11 , 24 . In short, tantalum foils are irradiated with a 1.4 GeV proton beam after which the generated radiolanthanides are released from the target, ionized, and accelerated as a radioactive ion beam (RIB) and subsequently implanted on a thin layer of aluminum, zinc or NaCl.…”

“…One disadvantage of this method is the potential contamination by pseudo-isobars in the final product, such as cerium-133m oxides. To obtain high radionuclidic purity, the use of cation exchange chromatography is crucial to further isolate terbium-149 from its daughter isotopes and pseudo-isobars 24 . To date, production yields ranging from few hundreds of MBq up to 1 GBq have been achieved at the ISOLDE facility, though access remains limited to a few times a year due to the competitive nature of the beam allocation at that facility.…”

Terbium Medical Radioisotope Production: Laser Resonance Ionization Scheme Development

“…This lanthanide element, entitled as "Swiss army knife" of nuclear medicine (9), offers four different radioisotopes to researchers providing a desired combination of α or β − therapy ( 149 Tb, 161 Tb) along with PET or SPECT imaging ( 152 Tb, 155 Tb) (10)(11)(12)(13)(14)(15). Whereas 161 Tb can be produced in nuclear reactors, the other three isotopes are available only at cyclotrons (16) or at radioactive ion beam facilities, like CERN-MEDICIS (17). Unfortunately, their production process is associated with high isobaric and isotopic contaminations, and, therefore, their use is not yet well-established (18).…”