155Tb production by cyclotrons: what level of 155Gd enrichment allows clinical applications?
Abstract Background 155Tb represents a potentially useful radionuclide for diagnostic medical applications, but its production remains a challenging problem, in spite of the fact that many production routes have been already investigated and tested. A recent experimental campaign, conducted with low...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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SpringerOpen
2024-03-01
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| Series: | EJNMMI Physics |
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| Online Access: | https://doi.org/10.1186/s40658-024-00630-6 |
| _version_ | 1827156461831061504 |
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| author | Francesca Barbaro Luciano Canton Nikolay Uzunov Laura De Nardo Laura Melendez-Alafort |
| author_facet | Francesca Barbaro Luciano Canton Nikolay Uzunov Laura De Nardo Laura Melendez-Alafort |
| author_sort | Francesca Barbaro |
| collection | DOAJ |
| description | Abstract Background 155Tb represents a potentially useful radionuclide for diagnostic medical applications, but its production remains a challenging problem, in spite of the fact that many production routes have been already investigated and tested. A recent experimental campaign, conducted with low-energy proton beams impinging on a 155Gd target with 91.9% enrichment, demonstrated a significant co-production of 156gTb, a contaminant of great concern since its half-life is comparable to that of 155Tb and its high-energy γ emissions severely impact on the dose released and on the quality of the SPECT images. In the present investigation, the isotopic purity of the enriched 155Gd target necessary to minimize the co-production of contaminant radioisotopes, in particular 156gTb, was explored using various computational simulations. Results Starting from the recent experimental data obtained with a 91.9% 155Gd-enriched target, the co-production of other Tb radioisotopes besides 155Tb has been theoretically evaluated using the Talys code. It was found that 156Gd, with an isotopic content of 5.87%, was the principal contributor to the co-production of 156gTb. The analysis also demonstrated that the maximum amount of 156Gd admissible for 155Tb production with a radionuclidic purity higher than 99% was 1%. A less stringent condition was obtained through computational dosimetry analysis, suggesting that a 2% content of 156Gd in the target can be tolerated to limit the dose increase to the patient below the 10% limit. Moreover, it has been demonstrated that the imaging properties of the produced 155Tb are not severely affected by this level of impurity in the target. Conclusions 155Tb can be produced with a quality suitable for medical applications using low-energy proton beams and 155Gd-enriched targets, if the 156Gd impurity content does not exceed 2%. Under these conditions, the dose increase due to the presence of contaminant radioisotopes remains below the 10% limit and good quality images, comparable to those of 111In, are guaranteed. |
| first_indexed | 2024-04-24T23:02:18Z |
| format | Article |
| id | doaj.art-20c44b1b0dd44ec5a93ff5a80b507204 |
| institution | Directory Open Access Journal |
| issn | 2197-7364 |
| language | English |
| last_indexed | 2025-03-20T23:09:49Z |
| publishDate | 2024-03-01 |
| publisher | SpringerOpen |
| record_format | Article |
| series | EJNMMI Physics |
| spelling | doaj.art-20c44b1b0dd44ec5a93ff5a80b5072042024-08-04T11:37:17ZengSpringerOpenEJNMMI Physics2197-73642024-03-0111112010.1186/s40658-024-00630-6155Tb production by cyclotrons: what level of 155Gd enrichment allows clinical applications?Francesca Barbaro0Luciano Canton1Nikolay Uzunov2Laura De Nardo3Laura Melendez-Alafort4INFN-Padua, National Institute of Nuclear PhysicsINFN-Padua, National Institute of Nuclear PhysicsINFN-Legnaro National Laboratories, National Institute of Nuclear PhysicsINFN-Padua, National Institute of Nuclear PhysicsVeneto Institute of Oncology IOV-IRCCSAbstract Background 155Tb represents a potentially useful radionuclide for diagnostic medical applications, but its production remains a challenging problem, in spite of the fact that many production routes have been already investigated and tested. A recent experimental campaign, conducted with low-energy proton beams impinging on a 155Gd target with 91.9% enrichment, demonstrated a significant co-production of 156gTb, a contaminant of great concern since its half-life is comparable to that of 155Tb and its high-energy γ emissions severely impact on the dose released and on the quality of the SPECT images. In the present investigation, the isotopic purity of the enriched 155Gd target necessary to minimize the co-production of contaminant radioisotopes, in particular 156gTb, was explored using various computational simulations. Results Starting from the recent experimental data obtained with a 91.9% 155Gd-enriched target, the co-production of other Tb radioisotopes besides 155Tb has been theoretically evaluated using the Talys code. It was found that 156Gd, with an isotopic content of 5.87%, was the principal contributor to the co-production of 156gTb. The analysis also demonstrated that the maximum amount of 156Gd admissible for 155Tb production with a radionuclidic purity higher than 99% was 1%. A less stringent condition was obtained through computational dosimetry analysis, suggesting that a 2% content of 156Gd in the target can be tolerated to limit the dose increase to the patient below the 10% limit. Moreover, it has been demonstrated that the imaging properties of the produced 155Tb are not severely affected by this level of impurity in the target. Conclusions 155Tb can be produced with a quality suitable for medical applications using low-energy proton beams and 155Gd-enriched targets, if the 156Gd impurity content does not exceed 2%. Under these conditions, the dose increase due to the presence of contaminant radioisotopes remains below the 10% limit and good quality images, comparable to those of 111In, are guaranteed.https://doi.org/10.1186/s40658-024-00630-6Terbium radioisotopes155Tb productionTheranosticsSPECT imagingGadolinium targetsProton-induced nuclear-reaction calculations |
| spellingShingle | Francesca Barbaro Luciano Canton Nikolay Uzunov Laura De Nardo Laura Melendez-Alafort 155Tb production by cyclotrons: what level of 155Gd enrichment allows clinical applications? EJNMMI Physics Terbium radioisotopes 155Tb production Theranostics SPECT imaging Gadolinium targets Proton-induced nuclear-reaction calculations |
| title | 155Tb production by cyclotrons: what level of 155Gd enrichment allows clinical applications? |
| title_full | 155Tb production by cyclotrons: what level of 155Gd enrichment allows clinical applications? |
| title_fullStr | 155Tb production by cyclotrons: what level of 155Gd enrichment allows clinical applications? |
| title_full_unstemmed | 155Tb production by cyclotrons: what level of 155Gd enrichment allows clinical applications? |
| title_short | 155Tb production by cyclotrons: what level of 155Gd enrichment allows clinical applications? |
| title_sort | 155tb production by cyclotrons what level of 155gd enrichment allows clinical applications |
| topic | Terbium radioisotopes 155Tb production Theranostics SPECT imaging Gadolinium targets Proton-induced nuclear-reaction calculations |
| url | https://doi.org/10.1186/s40658-024-00630-6 |
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