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Barbaro F, Canton L, Uzunov N, De Nardo L, Melendez-Alafort L. 155Tb production by cyclotrons: what level of 155Gd enrichment allows clinical applications? EJNMMI Phys 2024; 11:26. [PMID: 38485872 PMCID: PMC11286608 DOI: 10.1186/s40658-024-00630-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Accepted: 03/06/2024] [Indexed: 07/30/2024] Open
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.
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Affiliation(s)
- Francesca Barbaro
- INFN-Padua, National Institute of Nuclear Physics, Via Marzolo 8, 35131, Padua, Italy
- Department of Physics and Astronomy, University of Padua, Via Marzolo 8, 35131, Padua, Italy
| | - Luciano Canton
- INFN-Padua, National Institute of Nuclear Physics, Via Marzolo 8, 35131, Padua, Italy
| | - Nikolay Uzunov
- INFN-Legnaro National Laboratories, National Institute of Nuclear Physics, Viale Dell'Università 2, 35020, Legnaro, Italy
| | - Laura De Nardo
- INFN-Padua, National Institute of Nuclear Physics, Via Marzolo 8, 35131, Padua, Italy.
- Department of Physics and Astronomy, University of Padua, Via Marzolo 8, 35131, Padua, Italy.
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Barbaro F, Canton L, Carante MP, Colombi A, De Nardo L, Fontana A, Meléndez-Alafort L. The innovative 52g Mn for positron emission tomography (PET) imaging: Production cross section modeling and dosimetric evaluation. Med Phys 2023; 50:1843-1854. [PMID: 36433924 DOI: 10.1002/mp.16130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2022] [Revised: 09/14/2022] [Accepted: 10/10/2022] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND Manganese is a paramagnetic element suitable for magnetic resonance imaging (MRI) of neuronal function. However, high concentrations of Mn2 + can be neurotoxic. 52g Mn may be a valid alternative as positron emission tomography (PET) imaging agent, to obtain information similar to that delivered by MRI but using trace levels of Mn2 + , thus reducing its toxicity. Recently, the reaction n a t $^{nat}$ V(α,x)52g Mn has been proposed as a possible alternative to the standard n a t $^{nat}$ Cr(p,x)52g Mn one, but improvements in the modeling were needed to better compare the two production routes. PURPOSE This work focuses on the development of precise simulations and models to compare the 52g Mn production from both reactions in terms of amount of activity and radionuclidic purity (RNP), as well as in terms of dose increase (DI) due to the co-produced radioactive contaminants, versus pure 52g MnCl2 . METHODS The nuclear code Talys has been employed to optimize the n a t $^{nat}$ V(α,x)52g Mn cross section by tuning the parameters of the microscopic level densities. Thick-target yields have been calculated from the expression of the rates as energy convolution of cross sections and stopping powers, and finally integrating the time evolution of the relevant decay chains. Dosimetric assessments of [ x x $^{xx}$ Mn]Cl2 have been accomplished with OLINDA software 2.2.0 using female and male adult phantoms and biodistribution data for 52g MnCl2 in normal mice. At the end, the yield of x x $^{xx}$ Mn radioisotopes estimated for the two production routes have been combined with the dosimetric results, to assess the DI at different times after the end of the irradiation. RESULTS Good agreement was obtained between cross-section calculations and measurements. The comparison of the two reaction channels suggests that n a t $^{nat}$ V(α,x)52g Mn leads to higher yield and higher purity, resulting in more favorable radiation dosimetry for patients. CONCLUSIONS Both n a t $^{nat}$ V(α,x) and n a t $^{nat}$ Cr(p,x) production routes provide clinically acceptable 52g MnCl2 for PET imaging. However, the n a t $^{nat}$ V(α,x)52g Mn reaction provides a DI systematically lower than the one obtainable with n a t $^{nat}$ Cr(p,x)52g Mn and a longer time window in which it can be used clinically (RNP ≥ 99%).
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Affiliation(s)
- Francesca Barbaro
- INFN, Sezione di Padova, Padova, Italy
- Dipartimento di Fisica dell'Università di Pavia, Pavia, Italy
| | | | - Mario Pietro Carante
- Dipartimento di Fisica dell'Università di Pavia, Pavia, Italy
- INFN, Sezione di Pavia, Pavia, Italy
| | - Alessandro Colombi
- Dipartimento di Fisica dell'Università di Pavia, Pavia, Italy
- INFN, Sezione di Pavia, Pavia, Italy
| | - Laura De Nardo
- INFN, Sezione di Padova, Padova, Italy
- Dipartimento di Fisica e Astronomia dell'Università di Padova, Padova, Italy
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Nawar MF, Türler A. New strategies for a sustainable 99mTc supply to meet increasing medical demands: Promising solutions for current problems. Front Chem 2022; 10:926258. [PMID: 35936080 PMCID: PMC9355089 DOI: 10.3389/fchem.2022.926258] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Accepted: 06/27/2022] [Indexed: 11/13/2022] Open
Abstract
The continuing rapid expansion of 99mTc diagnostic agents always calls for scaling up 99mTc production to cover increasing clinical demand. Nevertheless, 99mTc availability depends mainly on the fission-produced 99Mo supply. This supply is seriously influenced during renewed emergency periods, such as the past 99Mo production crisis or the current COVID-19 pandemic. Consequently, these interruptions have promoted the need for 99mTc production through alternative strategies capable of providing clinical-grade 99mTc with high purity. In the light of this context, this review illustrates diverse production routes that either have commercially been used or new strategies that offer potential solutions to promote a rapid production growth of 99mTc. These techniques have been selected, highlighted, and evaluated to imply their impact on developing 99mTc production. Furthermore, their advantages and limitations, current situation, and long-term perspective were also discussed. It appears that, on the one hand, careful attention needs to be devoted to enhancing the 99Mo economy. It can be achieved by utilizing 98Mo neutron activation in commercial nuclear power reactors and using accelerator-based 99Mo production, especially the photonuclear transmutation strategy. On the other hand, more research efforts should be devoted to widening the utility of 99Mo/99mTc generators, which incorporate nanomaterial-based sorbents and promote their development, validation, and full automization in the near future. These strategies are expected to play a vital role in providing sufficient clinical-grade 99mTc, resulting in a reasonable cost per patient dose.
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Nuclear data for light charged particle induced production of emerging medical radionuclides. RADIOCHIM ACTA 2022. [DOI: 10.1515/ract-2022-0011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Abstract
Whatever the radionuclide to be used in nuclear medicine, it is essential to know the expected yield during the production process, but also of all the possible radionuclidic impurities coproduced, that can have an impact on the product final quality, as well as in the related waste management. The availability of the majority of emerging radioisotopes, including the theranostic ones or pairs, is mainly limited by the fact that, for most of them, the optimal production route still needs to be strengthened if not defined in some cases. The aim of this work is to present a review on the charged particle induced nuclear cross sections to produce some emerging radionuclides for medical applications to show that all types of projectiles should be considered in the quest of producing medical radionuclides. An accurate analysis of the production routes is presented for some radionuclides (67Cu, 47Sc, 89Zr, 103Pd, 186gRe, 97Ru, 211At) chosen as examples to highlight (i) how the quality of the final product strongly depends on the chosen target/projectile/energy parameters set, (ii) how deuteron production routes may sometimes be more effective than the proton ones or lead to a different impurity profile and (iii) how α-particle beams may allow to bypass the limitations occurring when using Z = 1 beams. An overview of possible advantages and drawbacks of the cited production routes and of potential cross sections that still need to be measured, is also reported.
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De Nardo L, Pupillo G, Mou L, Esposito J, Rosato A, Meléndez‐Alafort L. A feasibility study of the therapeutic application of a mixture of 67/64 Cu radioisotopes produced by cyclotrons with proton irradiation. Med Phys 2022; 49:2709-2724. [PMID: 35134261 PMCID: PMC9305914 DOI: 10.1002/mp.15524] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 01/21/2022] [Accepted: 01/29/2022] [Indexed: 11/26/2022] Open
Abstract
PURPOSE 64 Cu and 67 Cu radioisotopes have nuclear characteristics suitable for nuclear medicine applications. The production of 64 Cu is already well established. However, the production of 67 Cu in quantities suitable to conduct clinical trials is more challenging as it leads to the coproduction of other Cu isotopes, in particular 64 Cu. The aim of this study is to investigate the possibility of using a CuCl2 solution with a mixture of 67/64 Cu radioisotopes for therapeutic purposes, providing an alternative solution for the cyclotron production problem. METHODS Copper radioisotopes activities were calculated by considering proton beam irradiation of the following targets: (i) 70 Zn in the energy range 70-45 MeV; (ii) 68 Zn in the energy range 70-35 MeV; (iii) a combination of 70 Zn (70-55 MeV) and 68 Zn (55-35 MeV). The contribution of each copper radioisotope to the human-absorbed dose was estimated with OLINDA/EXM software using the biokinetic model for CuCl2 published by ICRP 53. The total absorbed dose generated by the 67/64 CuCl2 mixture, obtained through different production routes, was calculated at different times after the end of the bombardment (EOB). A simple spherical model was used to simulate tumors of different sizes containing uniformly distributed 67/64 Cu mixture and to calculate the absorbed dose of self-irradiation. The biological damage produced by 67 Cu and 64 Cu was also evaluated through cellular dosimetry and cell surviving fraction assessment using the MIRDcell code, considering two prostate cancer cell lines with different radiosensitivity. RESULTS The absorbed dose to healthy organs and the effective dose (ED) per unit of administered activity of 67 CuCl2 are higher than those of 64 CuCl2 . Absorbed dose values per unit of administered activity of 67/64 CuCl2 mixture increase with time after the EOB because the amount of 67 Cu in the mixture increases. Survival data showed that the biological damage caused per each decay of 67 Cu is greater than that of 64 Cu, assuming that radionuclides remain accumulated in the cell cytoplasm. Sphere model calculations demonstrated that 64 Cu administered activity must be about five times higher than that of 67 Cu to obtain the same absorbed dose for tumor mass between 0.01 and 10 g and about 10 times higher for very small spheres. Consequently, the 64 CuCl2 -absorbed dose to healthy organs will reach higher values than those of 67 CuCl2 . The supplemental activity of the 67/64 CuCl2 mixture, required to get the same tumor-absorbed dose produced by 67 CuCl2 , triggers a dose increment (DI) in healthy organs. The waiting time post-EOB necessary to keep this DI below 10% (t10% ) depends on the irradiation methods employed for the production of the 67/64 CuCl2 mixture. CONCLUSIONS A mixture of cyclotron produced 67/64 Cu radioisotopes proved to be an alternative solution for the therapeutic use of CuCl2 with minimal DI to healthy organs compared with pure 67 Cu. Irradiation of a 70 Zn+68 Zn target in the 70-35 MeV proton energy range for 185 h appears to be the best option from among all the production routes investigated, as it gives the maximum amount of activity, the shortest t10% (10 h), and less than 1% of 61 Cu and 60 Cu impurities.
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Affiliation(s)
- Laura De Nardo
- Department of Physics and AstronomyUniversity of PaduaVia Marzolo 8Padova35131Italy
- INFN‐PadovaNational Institute of Nuclear PhysicsVia Marzolo 8Padova35131Italy
| | - Gaia Pupillo
- INFN‐Legnaro National LaboratoriesNational Institute of Nuclear PhysicsViale dell'Università 2Legnaro35020Italy
| | - Liliana Mou
- INFN‐Legnaro National LaboratoriesNational Institute of Nuclear PhysicsViale dell'Università 2Legnaro35020Italy
| | - Juan Esposito
- INFN‐Legnaro National LaboratoriesNational Institute of Nuclear PhysicsViale dell'Università 2Legnaro35020Italy
| | - Antonio Rosato
- Department of SurgeryOncology and GastroenterologyUniversity of PaduaPadovaItaly
- Veneto Institute of Oncology IOV‐IRCCSVia Gattamelata 64Padova35138Italy
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Jang J, Kumakura Y, Tatenuma K, Ozeki AN, Wada Y, Akimitsu N, Tsuguchi A, Kikunaga H, Higaki S, Uesaka M. A preliminary biodistribution study of [99mTc]sodium pertechnetate prepared from an electron linear accelerator and activated carbon-based 99mTc generator. Nucl Med Biol 2022; 110-111:1-9. [DOI: 10.1016/j.nucmedbio.2022.03.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Revised: 03/05/2022] [Accepted: 03/08/2022] [Indexed: 11/30/2022]
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Meléndez-Alafort L, Ferro-Flores G, Santos-Cuevas C, Ocampo-García B, Turato S, Fracasso G, Bolzati C, Rosato A, De Nardo L. Preclinical dosimetric studies of 177 Lu-scFvD2B and comparison with 177 Lu-PSMA-617 and 177 Lu-iPSMA endoradiotherapeutic agents. Med Phys 2021; 48:4064-4074. [PMID: 33966284 DOI: 10.1002/mp.14936] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Revised: 04/19/2021] [Accepted: 04/30/2021] [Indexed: 11/08/2022] Open
Abstract
PURPOSE Internal dosimetry has become a very important tool to evaluate the risks and benefits of new endoradiotherapeutic agents. Nowadays, some of the most successful targeted radionuclide therapy (TRT) agents are 177 Lu-DOTA conjugates based on low molecular weight (LMW) Glu-ureido PSMA inhibitors. It has, however, been demonstrated that the DOTA chelating moiety reduces the internalization of the LMW-PSMA agent and its radiation dose to the tumor. Previously, we reported that 177 Lu-scFvD2B, an antibody-based construct, demonstrated statistically significant higher cell uptake and internalization in LNCaP prostate cancer (PCa) cells (PSMA-positive) when compared to the LMW-PSMA agents, 177 Lu-PSMA-617 and 177 Lu-iPSMA, two of the endoradiotherapeutic agents which currently are the most used in PCa therapy. The aim of this study is to estimate the preclinical 177 Lu-scFvD2B organ and tumor-absorbed doses, and to compare the values with those of 177 Lu-PSMA-617 and 177 Lu-iPSMA. METHODS 177 Lu-scFvD2B, 177 Lu-PSMA-617, and 177 Lu-iPSMA were prepared and their radiochemical purity determined. Biodistribution studies of each radiopharmaceutical were then carried out in healthy mice to define the main source organs (SO) and to calculate the number of disintegrations in each source organs per unit of administered activity (NSO ). Absorbed dose in the main organs were then calculated for each 177 Lu-conjugate by means of OLINDA/EXM 2.1.1 software, using the calculated NSO for both the adult male and the mouse phantoms as program inputs. Images of mice bearing micropulmonary tumors injected with 177 Lu-conjugates were also obtained. Tumor standardized uptake values (SUV) for the different conjugates, obtained from the 3D SPECT image reconstruction of these mice, were used as the number of disintegrations in a tumor site per unit of administered activity (NT ). The tumor-absorbed dose was calculated using the published electron dose S-values for sphere models with diameters ranging from 10 µm to 10 mm and considering a uniform activity distribution and tumor density equivalent to water density. RESULTS All 177 Lu-labeled agents were obtained in high yield (98%). Dosimetric studies carried out using mouse phantoms demonstrated that organ absorbed doses of 177 Lu-scFvD2B were from 1.4 to 2.3 times higher than those for 177 Lu-iPSMA and from 1.5 to 2.6 times higher than those for 177 Lu-PSMA-617. However, the 177 Lu-scFvD2B values of tumor-absorbed doses for all investigated tumor sizes were from 2.8 to 3.0 times greater than those calculated for 177 Lu-iPSMA and 177 Lu-PSMA-617, respectively. Moreover, 177 Lu-scFvD2B showed the highest tumor/kidney ratio when compared to those reported for 177 Lu-albumin conjugates. CONCLUSIONS In this preclinical study, we demonstrated the potential of 177 Lu-scFvD2B as a therapeutic agent for PSMA-expressing tumors, due to its higher tumor-absorbed dose when compared with 177 Lu-LMW agents.
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Affiliation(s)
| | - Guillermina Ferro-Flores
- Laboratorio Nacional de Investigación y Desarrollo de Radiofármacos-CONACyT, Instituto Nacional de Investigaciones Nucleares, Carretera México-Toluca S/N, La Marquesa, Ocoyoacac,, 52750, Estado de México, México
| | - Clara Santos-Cuevas
- Laboratorio Nacional de Investigación y Desarrollo de Radiofármacos-CONACyT, Instituto Nacional de Investigaciones Nucleares, Carretera México-Toluca S/N, La Marquesa, Ocoyoacac,, 52750, Estado de México, México
| | - Blanca Ocampo-García
- Laboratorio Nacional de Investigación y Desarrollo de Radiofármacos-CONACyT, Instituto Nacional de Investigaciones Nucleares, Carretera México-Toluca S/N, La Marquesa, Ocoyoacac,, 52750, Estado de México, México
| | - Sofia Turato
- Veneto Institute of Oncology IOV-IRCCS, Via Gattamelata 64, 35138, Padua, Italy
| | - Giulio Fracasso
- Department of Medicine, University of Verona, Piaz. Le L.A. Scuro 10, 37134, Verona, Italy
| | - Cristina Bolzati
- Institute of Condensed Matter Chemistry and Energy Technologies, ICMATE-CNR, Corso Stati Uniti 4, 35127, Padua, Italy
| | - Antonio Rosato
- Veneto Institute of Oncology IOV-IRCCS, Via Gattamelata 64, 35138, Padua, Italy.,Department of Surgery, Oncology and Gastroenterology, University of Padua, Via Gattamelata 64, 35138, Padua, Italy
| | - Laura De Nardo
- Department of Physics and Astronomy, University of Padua, Via Marzolo 8, 35131, Padua, Italy.,INFN, Sezione di Padova, Via Marzolo 8, 35131, Padua, Italy
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Cawthorne C, Maguire P, Mercier J, Sciberras D, Serdons K, Bormans G, de Hoon J, Van Laere K, Koole M. Human biodistribution and dosimetry of [ 11C]-UCB-J, a PET radiotracer for imaging synaptic density. EJNMMI Phys 2021; 8:37. [PMID: 33891195 PMCID: PMC8065069 DOI: 10.1186/s40658-021-00384-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Accepted: 04/13/2021] [Indexed: 11/10/2022] Open
Abstract
RATIONALE [11C]-UCB-J is an emerging tool for the noninvasive measurement of synaptic vesicle density in vivo. Here, we report human biodistribution and dosimetry estimates derived from sequential whole-body PET using two versions of the OLINDA dosimetry program. METHODS Sequential whole-body PET scans were performed in 3 healthy subjects for 2 h after injection of 254 ± 77 MBq [11C]-UCB-J. Volumes of interest were drawn over relevant source organs to generate time-activity curves and calculate time-integrated activity coefficients, with effective dose coefficients calculated using OLINDA 2.1 and compared to values derived from OLINDA 1.1 and those recently reported in the literature. RESULTS [11C]-UCB-J administration was safe and showed mixed renal and hepatobiliary clearance, with largest organ absorbed dose coefficients for the urinary bladder wall and small intestine (21.7 and 23.5 μGy/MBq, respectively). The average (±SD) effective dose coefficient was 5.4 ± 0.7 and 5.1 ± 0.8 μSv/MBq for OLINDA versions 1.1 and 2.1 respectively. Doses were lower than previously reported in the literature using either software version. CONCLUSIONS A single IV administration of 370 MBq [11C]-UCB-J corresponds to an effective dose of less than 2.0 mSv, enabling multiple PET examinations to be carried out in the same subject. TRIAL REGISTRATION EudraCT number: 2016-001190-32. Registered 16 March 2016, no URL available for phase 1 trials.
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Affiliation(s)
- Christopher Cawthorne
- Nuclear Medicine and Molecular Imaging, Department of Imaging and Pathology, KU Leuven, Leuven, Belgium
| | | | | | | | - Kim Serdons
- Division of Nuclear Medicine, University Hospitals Leuven, Leuven, Belgium
| | - Guy Bormans
- Laboratory for Radiopharmaceutical Research, KU Leuven, Leuven, Belgium
| | - Jan de Hoon
- Center for Clinical Pharmacology, University Hospitals Leuven, Leuven, Belgium
| | - Koen Van Laere
- Nuclear Medicine and Molecular Imaging, Department of Imaging and Pathology, KU Leuven, Leuven, Belgium.,Division of Nuclear Medicine, University Hospitals Leuven, Leuven, Belgium
| | - Michel Koole
- Nuclear Medicine and Molecular Imaging, Department of Imaging and Pathology, KU Leuven, Leuven, Belgium.
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Nardo LD, Pupillo G, Mou L, Furlanetto D, Rosato A, Esposito J, Meléndez-Alafort L. Preliminary dosimetric analysis of DOTA-folate radiopharmaceutical radiolabelled with 47Sc produced through natV(p,x) 47Sc cyclotron irradiation. Phys Med Biol 2021; 66:025003. [PMID: 33480361 DOI: 10.1088/1361-6560/abc811] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
47Sc is one of the most promising theranostic radionuclides, thanks to its low energy γ-ray emission (159 keV), suitable for single photon emission computed tomography imaging and its intense β - emission, useful for tumour treatment. Despite promising preclinical results, the translation of 47Sc-therapeutic agents to the clinic is hampered by its limited availability. Among different 47Sc-production routes currently being investigated, the natV(p,x)47Sc reaction has proved to be of particular interest, thanks to the low-cost and easy availability on the market of natV material and the diffusion of medium energy proton cyclotrons. However, the cross section of this specific nuclear reaction is quite low and small amounts of Sc-contaminants are co-produced at energies E P ≤ 45 MeV, namely 48Sc and 46Sc. The main concern with these Sc-contaminants is their contribution to the patient absorbed dose. For such a reason, the absorbed dose contributions to healthy organs and the effective dose contributions by the three radioisotopes, 48Sc, 47Sc and 46Sc, were evaluated using DOTA-folate conjugate (cm10) as an example of radiopharmaceutical product. Considering as acceptable the limits of 99% for the radionuclidic purity and 10% for the contribution of radioactive Sc-contaminants to the total effective dose after 47Sc-cm10 injection, it was obtained that proton beam energies below 35 MeV must be used to produce 47Sc through irradiation of a natV target.
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Affiliation(s)
- L De Nardo
- Department of Physics and Astronomy, University of Padova, Via Marzolo 8, Padova 35131, Italy. INFN (Istituto Nazionale di Fisica Nucleare), Sezione di Padova, Via Marzolo 8, Padova 35131, Italy
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Hasan S, Prelas MA. Molybdenum-99 production pathways and the sorbents for 99Mo/99mTc generator systems using (n, γ) 99Mo: a review. SN APPLIED SCIENCES 2020. [DOI: 10.1007/s42452-020-03524-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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