1
|
Brühlmann SA, Walther M, Blei MK, Mamat C, Kopka K, Freudenberg R, Kreller M. Scalability study on [ 133La]LaCl 3 production with a focus on potential clinical applications. EJNMMI Radiopharm Chem 2024; 9:60. [PMID: 39147960 PMCID: PMC11327230 DOI: 10.1186/s41181-024-00292-w] [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: 05/16/2024] [Accepted: 08/05/2024] [Indexed: 08/17/2024] Open
Abstract
BACKGROUND In recent years, targeted alpha therapy has gained importance in the clinics, and in particular, the alpha-emitter 225Ac plays a fundamental role in this clinical development. Nevertheless, depending on the chelating system no real diagnostic alternative has been established which shares similar chemical properties with this alpha-emitting radionuclide. In fact, the race to launch a diagnostic radionuclide to form a matched pair with 225Ac is still open, and 133La features attractive radiation properties to claim this place. However, in order to enable its translation into clinical use, upscaling of the production of this PET radionuclide is needed. RESULTS A study on optimal irradiation parameters, separation conditions and an exhaustive product characterization was carried out. In this framework, a proton irradiation of 2 h, 60 µA and 18.7 MeV produced 133La activities of up to 10.7 GBq at end of bombardment. In addition, the performance of four different chromatographic resins were tested and two optimized purification methods presented, taking approximately 20 min with a 133La recovery efficiencies of over 98%, decay corrected. High radionuclide purity and apparent molar activity was proved, of over 99.5% and 120 GBq/µmol, respectively, at end of purification. Furthermore, quantitative complexation of PSMA-617 and mcp-M-PSMA were obtained with molar activities up to 80 GBq/µmol. In addition, both 133La-radioconjugates offered high stability in serum, of over (98.5 ± 0.3)% and (99.20 ± 0.08)%, respectively, for up to 24 h. A first dosimetry estimation was also performed and it was calculated that an 133La application for imaging with between 350 and 750 MBq would only have an effective dose of 2.1-4.4 mSv, which is comparable to that of 18F and 68Ga based radiopharmaceuticals. CONCLUSIONS In this article we present an overarching study on 133La production, from the radiation parameters optimization to a clinical dose estimation. Lanthanum-133 activities in the GBq range could be produced, formulated as [133La]LaCl3 with high quality regarding radiolabeling and radionuclide purity. We believe that increasing the 133La availability will further promote the development of radiopharmaceuticals based on macropa or other chelators suitable for 225Ac.
Collapse
Affiliation(s)
- Santiago Andrés Brühlmann
- Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, 01328, Dresden, Germany
- Faculty of Chemistry and Food Chemistry, School of Science, Technische Universität Dresden, 01062, Dresden, Germany
| | - Martin Walther
- Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, 01328, Dresden, Germany.
| | - Magdalena Kerstin Blei
- Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, 01328, Dresden, Germany
- Faculty of Chemistry and Food Chemistry, School of Science, Technische Universität Dresden, 01062, Dresden, Germany
| | - Constantin Mamat
- Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, 01328, Dresden, Germany
- Faculty of Chemistry and Food Chemistry, School of Science, Technische Universität Dresden, 01062, Dresden, Germany
| | - Klaus Kopka
- Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, 01328, Dresden, Germany
- Faculty of Chemistry and Food Chemistry, School of Science, Technische Universität Dresden, 01062, Dresden, Germany
- National Center for Tumor Diseases (NCT) Dresden, University Hospital Carl Gustav Carus, Fetscherstraße 74, 01307, Dresden, Germany
- German Cancer Consortium (DKTK), Partner Site Dresden, Fetscherstraße 74, 01307, Dresden, Germany
| | - Robert Freudenberg
- Department of Nuclear Medicine, University Hospital Carl Gustav Carus, Fetscherstraße 74, 01307, Dresden, Germany
| | - Martin Kreller
- Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, 01328, Dresden, Germany
| |
Collapse
|
2
|
Miederer M, Benešová-Schäfer M, Mamat C, Kästner D, Pretze M, Michler E, Brogsitter C, Kotzerke J, Kopka K, Scheinberg DA, McDevitt MR. Alpha-Emitting Radionuclides: Current Status and Future Perspectives. Pharmaceuticals (Basel) 2024; 17:76. [PMID: 38256909 PMCID: PMC10821197 DOI: 10.3390/ph17010076] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Revised: 12/27/2023] [Accepted: 12/28/2023] [Indexed: 01/24/2024] Open
Abstract
The use of radionuclides for targeted endoradiotherapy is a rapidly growing field in oncology. In particular, the focus on the biological effects of different radiation qualities is an important factor in understanding and implementing new therapies. Together with the combined approach of imaging and therapy, therapeutic nuclear medicine has recently made great progress. A particular area of research is the use of alpha-emitting radionuclides, which have unique physical properties associated with outstanding advantages, e.g., for single tumor cell targeting. Here, recent results and open questions regarding the production of alpha-emitting isotopes as well as their chemical combination with carrier molecules and clinical experience from compassionate use reports and clinical trials are discussed.
Collapse
Affiliation(s)
- Matthias Miederer
- Department of Translational Imaging in Oncology, National Center for Tumor Diseases (NCT/UCC), 01307 Dresden, Germany
- Medizinische Fakultät and University Hospital Carl Gustav Carus, Technische Universität Dresden, 01307 Dresden, Germany
- German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
- Helmholtz-Zentrum Dresden-Rossendorf (HZDR), 01328 Dresden, Germany
| | - Martina Benešová-Schäfer
- Research Group Molecular Biology of Systemic Radiotherapy, German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany;
| | - Constantin Mamat
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Bautzner Landstr, 400, 01328 Dresden, Germany
- School of Science, Faculty of Chemistry and Food Chemistry, Technische Universität Dresden, 01062 Dresden, Germany
| | - David Kästner
- Department of Nuclear Medicine, University Hospital Carl Gustav Carus, Technische Universität Dresden, Fetscherstraße 74, 01307 Dresden, Germany; (D.K.); (C.B.)
| | - Marc Pretze
- Department of Nuclear Medicine, University Hospital Carl Gustav Carus, Technische Universität Dresden, Fetscherstraße 74, 01307 Dresden, Germany; (D.K.); (C.B.)
| | - Enrico Michler
- Department of Nuclear Medicine, University Hospital Carl Gustav Carus, Technische Universität Dresden, Fetscherstraße 74, 01307 Dresden, Germany; (D.K.); (C.B.)
| | - Claudia Brogsitter
- Department of Nuclear Medicine, University Hospital Carl Gustav Carus, Technische Universität Dresden, Fetscherstraße 74, 01307 Dresden, Germany; (D.K.); (C.B.)
| | - Jörg Kotzerke
- Medizinische Fakultät and University Hospital Carl Gustav Carus, Technische Universität Dresden, 01307 Dresden, Germany
- Department of Nuclear Medicine, University Hospital Carl Gustav Carus, Technische Universität Dresden, Fetscherstraße 74, 01307 Dresden, Germany; (D.K.); (C.B.)
| | - Klaus Kopka
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Bautzner Landstr, 400, 01328 Dresden, Germany
- School of Science, Faculty of Chemistry and Food Chemistry, Technische Universität Dresden, 01062 Dresden, Germany
- National Center for Tumor Diseases (NCT) Dresden, University Hospital Carl Gustav Carus, Fetscherstraße 74, 01307 Dresden, Germany
- German Cancer Consortium (DKTK), Partner Site Dresden, Fetscherstraße 74, 01307 Dresden, Germany
| | - David A. Scheinberg
- Molecular Pharmacology Program, Sloan Kettering Institute, New York, NY 10065, USA;
| | - Michael R. McDevitt
- Molecular Imaging and Therapy Service, Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
- Department of Radiology, Weill Cornell Medical College, New York, NY 10065, USA
| |
Collapse
|
3
|
Brühlmann SA, Walther M, Kopka K, Kreller M. Production of the PET radionuclide 61Cu via the 62Ni(p,2n) 61Cu nuclear reaction. EJNMMI Radiopharm Chem 2024; 9:3. [PMID: 38180574 PMCID: PMC10770005 DOI: 10.1186/s41181-023-00233-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2023] [Accepted: 12/21/2023] [Indexed: 01/06/2024] Open
Abstract
BACKGROUND There are only a handful of true theranostic matched pairs, and in particular the theranostic radiocopper trio 61Cu, 64Cu and 67Cu, for diagnosis and therapy respectively, is a very attractive candidate. In fact, the alternative of two imaging radionuclides with different half-lives is a clear advantage over other theranostic pairs, since it offers a better matching for the tracer biological and radionuclide physical half-lives. Due to the high availability of 64Cu, its translation into the clinic is being successfully carried out, giving the example of the FDA approved radiopharmaceutical Detectnet (copper Cu 64 dotatate injection). However, a shorter-lived PET radionuclide such as 61Cu may as well be beneficial. RESULTS Proton irradiation of enriched 62Ni electrodeposited targets with a compact cyclotron produced the desired radionuclide via the 62Ni(p,2n)61Cu nuclear reaction, leading to 61Cu activities of up to 20 GBq at end of bombardment and 8 GBq at end of purification. Furthermore, two purification methods are compared leading to comparable results regarding separation yield and product purity. Following the radiochemical separation, quality assessment of this product [61Cu]CuCl2 solution proved radionuclidic purities (RNP) over 99.6% and apparent molar activities (AMA) of 260 GBq/µmol with the 1,4,8,11-tetraazacyclotetradecane-1,4,8,11-tetraacetic acid (TETA) chelator, end of purification corrected. CONCLUSIONS In the current article a comprehensive novel production method for the PET radionuclide 61Cu is presented, providing an alternative to the most popular production routes. Characterization of the [61Cu]CuCl2 product showed both high RNP as well as high AMA, proving that the produced activity presented high quality regarding radiolabeling up to 9 h after end of purification. Furthermore, production scalability could be easily achieved by increasing the irradiation time.
Collapse
Affiliation(s)
- Santiago Andrés Brühlmann
- Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, 01328, Dresden, Germany
- Faculty of Chemistry and Food Chemistry, School of Science, Technische Universität Dresden, 01062, Dresden, Germany
| | - Martin Walther
- Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, 01328, Dresden, Germany.
| | - Klaus Kopka
- Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, 01328, Dresden, Germany
- Faculty of Chemistry and Food Chemistry, School of Science, Technische Universität Dresden, 01062, Dresden, Germany
- National Center for Tumor Diseases (NCT) Dresden, University Hospital Carl Gustav Carus, Fetscherstraße 74, 01307, Dresden, Germany
- German Cancer Consortium (DKTK), Partner Site Dresden, Fetscherstraße 74, 01307, Dresden, Germany
| | - Martin Kreller
- Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, 01328, Dresden, Germany
| |
Collapse
|
4
|
Kopp I, Cieslik P, Anger K, Josephy T, Neupert L, Velmurugan G, Gast M, Wadepohl H, Brühlmann SA, Walther M, Kopka K, Bachmann M, Stephan H, Kubeil M, Comba P. Bispidine Chelators for Radiopharmaceutical Applications with Lanthanide, Actinide, and Main Group Metal Ions. Inorg Chem 2023; 62:20754-20768. [PMID: 37707798 DOI: 10.1021/acs.inorgchem.3c02340] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/15/2023]
Abstract
Octadentate and specifically nonadentate ligands with a bispidine scaffold (3,7-diazabicyclo[3.3.1]nonane) are known to be efficiently coordinated to a range of metal ions of interest in radiopharmaceutical chemistry and lead to exceedingly stable and inert complexes. Nonadentate bispidine L2 (with a tridentate bipyridine acetate appended to N3 and a picolinate at N7) has been shown before to be an ideal chelator for 111In3+, 177Lu3+, and 225Ac3+, nuclides of interest for diagnosis and therapy, and a proof-of-principle study with an SSTR2-specific octreotate has shown potential for theranostic applications. We now have extended these studies in two directions. First, we present ligand derivative L3, in which the bipyridine acetate is substituted with terpyridine, a softer donor for metal ions with a preference for more covalency. L3 did not fulfill the hopes because complexation is much less efficient. While for Bi3+ and Pb2+ the ligand is an excellent chelator with properties similar to those of L2, Lu3+ and La3+ show very slow and inefficient complexation with L3 in contrast to L2, and 225Ac3+ is not fully coordinated, even at an increased temperature (92% radiochemical yield at 80 °C, 60 min, [L3] = 10-4 M). These observations have led to a hypothesis for the complexation pathway that is in line with all of the experimental data and supported by a preliminary density functional theory analysis, which is important for the design of further optimized bispidine chelators. Second, the coordination chemistry of L2 has been extended to Bi3+, La3+, and Pb2+, including solid state and solution structural work, complex stabilities, radiolabeling, and radiostability studies. All complexes of this ligand (La3+, Ac3+, Lu3+, Bi3+, In3+, and Pb2+), including nuclides for targeted α therapy (TAT), single-photon emission computed tomography, and positron emission tomography, are formed efficiently under physiological conditions, i.e., suitable for the labeling of delicate biological vectors such as antibodies, and the complexes are very stable and inert. Importantly, for TAT with 225Ac, the daughter nuclides 213Bi and 209Pb also form stable complexes, and this is important for reducing damage to healthy tissue.
Collapse
Affiliation(s)
- Ina Kopp
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Bautzner Landstraße 400, 01328 Dresden, Germany
| | - Patrick Cieslik
- Universität Heidelberg, Anorganisch-Chemisches Institut, INF 270, 69120 Heidelberg, Germany
| | - Karl Anger
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Bautzner Landstraße 400, 01328 Dresden, Germany
| | - Thomas Josephy
- Universität Heidelberg, Anorganisch-Chemisches Institut, INF 270, 69120 Heidelberg, Germany
| | - Lucca Neupert
- Universität Heidelberg, Anorganisch-Chemisches Institut, INF 270, 69120 Heidelberg, Germany
| | - Gunasekaran Velmurugan
- Universität Heidelberg, Anorganisch-Chemisches Institut, INF 270, 69120 Heidelberg, Germany
| | - Michael Gast
- Universität Heidelberg, Anorganisch-Chemisches Institut, INF 270, 69120 Heidelberg, Germany
| | - Hubert Wadepohl
- Universität Heidelberg, Anorganisch-Chemisches Institut, INF 270, 69120 Heidelberg, Germany
| | - Santiago Andrés Brühlmann
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Bautzner Landstraße 400, 01328 Dresden, Germany
| | - Martin Walther
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Bautzner Landstraße 400, 01328 Dresden, Germany
| | - Klaus Kopka
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Bautzner Landstraße 400, 01328 Dresden, Germany
- Technische Universität Dresden, Faculty of Chemistry and Food Chemistry, School of Science, 01069 Dresden, Germany
- National Center for Tumor Diseases (NCT) Dresden, University Hospital Carl Gustav Carus, Fetscherstraße 74, 01307 Dresden, Germany
- German Cancer Consortium (DKTK), Partner Site Dresden, 01307 Dresden, Germany
| | - Michael Bachmann
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Bautzner Landstraße 400, 01328 Dresden, Germany
- National Center for Tumor Diseases (NCT) Dresden, University Hospital Carl Gustav Carus, Fetscherstraße 74, 01307 Dresden, Germany
- Technische Universität Dresden, Medical Faculty Carl Gustav Carus, 01069 Dresden, Germany
| | - Holger Stephan
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Bautzner Landstraße 400, 01328 Dresden, Germany
| | - Manja Kubeil
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Bautzner Landstraße 400, 01328 Dresden, Germany
| | - Peter Comba
- Universität Heidelberg, Anorganisch-Chemisches Institut, INF 270, 69120 Heidelberg, Germany
- Universität Heidelberg, Interdisciplinary Center for Scientific Computing, INF 205, 69120 Heidelberg, Germany
| |
Collapse
|
5
|
Blei M, Waurick L, Reissig F, Kopka K, Stumpf T, Drobot B, Kretzschmar J, Mamat C. Equilibrium Thermodynamics of Macropa Complexes with Selected Metal Isotopes of Radiopharmaceutical Interest. Inorg Chem 2023; 62:20699-20709. [PMID: 37702665 PMCID: PMC10731647 DOI: 10.1021/acs.inorgchem.3c01983] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Indexed: 09/14/2023]
Abstract
To pursue the design of in vivo stable chelating systems for radiometals, a concise and straightforward method toolbox was developed combining NMR, isothermal titration calorimetry (ITC), and europium time-resolved laser-induced fluorescence spectroscopy (Eu-TRLFS). For this purpose, the macropa chelator was chosen, and Lu3+, La3+, Pb2+, Ra2+, and Ba2+ were chosen as radiopharmaceutically relevant metal ions. They differ in charge (2+ and 3+) and coordination properties (main group vs lanthanides). 1H NMR was used to determine four pKa values (±0.15; carboxylate functions, 2.40 and 3.13; amino functions, 6.80 and 7.73). Eu-TRLFS was used to validate the exclusive existence of the 1:1 Mn+/ligand complex in the chosen pH range at tracer level concentrations. ITC measurements were accomplished to determine the resulting stability constants of the desired complexes, with log K values ranging from 18.5 for the Pb-mcp complex to 7.3 for the Lu-mcp complex. Density-functional-theory-calculated structures nicely mirror the complexes' order of stabilities by bonding features. Radiolabeling with macropa using ligand concentrations from 10-3 to 10-6 M was accomplished by pointing out the complex formation and stability (212Pb > 133La > 131Ba ≈ 224Ra > 177Lu) by means of normal-phase thin-layer chromatography analyses.
Collapse
Affiliation(s)
- Magdalena
K. Blei
- Helmholtz-Zentrum
Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Bautzner Landstraße 400, D-01328 Dresden, Germany
- TU
Dresden, Faculty of Chemistry and Food Chemistry, D-01062 Dresden, Germany
| | - Lukas Waurick
- TU
Dresden, Faculty of Chemistry and Food Chemistry, D-01062 Dresden, Germany
- Helmholtz-Zentrum
Dresden-Rossendorf, Institute of Resource Ecology, Bautzner Landstraße 400, D-01328 Dresden, Germany
| | - Falco Reissig
- Helmholtz-Zentrum
Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Bautzner Landstraße 400, D-01328 Dresden, Germany
| | - Klaus Kopka
- Helmholtz-Zentrum
Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Bautzner Landstraße 400, D-01328 Dresden, Germany
- TU
Dresden, Faculty of Chemistry and Food Chemistry, D-01062 Dresden, Germany
- National
Center for Tumor Diseases, University Cancer Center, University Hospital Carl Gustav Carus Dresden, Fetscherstraße 74, D-01307 Dresden, Germany
- German
Cancer Consortium, Partner Site Dresden, Fetscherstraße 74, D-01307 Dresden, Germany
| | - Thorsten Stumpf
- TU
Dresden, Faculty of Chemistry and Food Chemistry, D-01062 Dresden, Germany
- Helmholtz-Zentrum
Dresden-Rossendorf, Institute of Resource Ecology, Bautzner Landstraße 400, D-01328 Dresden, Germany
| | - Björn Drobot
- Helmholtz-Zentrum
Dresden-Rossendorf, Institute of Resource Ecology, Bautzner Landstraße 400, D-01328 Dresden, Germany
| | - Jerome Kretzschmar
- Helmholtz-Zentrum
Dresden-Rossendorf, Institute of Resource Ecology, Bautzner Landstraße 400, D-01328 Dresden, Germany
| | - Constantin Mamat
- Helmholtz-Zentrum
Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Bautzner Landstraße 400, D-01328 Dresden, Germany
- TU
Dresden, Faculty of Chemistry and Food Chemistry, D-01062 Dresden, Germany
| |
Collapse
|
6
|
Nelson BJB, Wilson J, Andersson JD, Wuest F. Theranostic Imaging Surrogates for Targeted Alpha Therapy: Progress in Production, Purification, and Applications. Pharmaceuticals (Basel) 2023; 16:1622. [PMID: 38004486 PMCID: PMC10674391 DOI: 10.3390/ph16111622] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Revised: 11/08/2023] [Accepted: 11/14/2023] [Indexed: 11/26/2023] Open
Abstract
This article highlights recent developments of SPECT and PET diagnostic imaging surrogates for targeted alpha particle therapy (TAT) radiopharmaceuticals. It outlines the rationale for using imaging surrogates to improve diagnostic-scan accuracy and facilitate research, and the properties an imaging-surrogate candidate should possess. It evaluates the strengths and limitations of each potential imaging surrogate. Thirteen surrogates for TAT are explored: 133La, 132La, 134Ce/134La, and 226Ac for 225Ac TAT; 203Pb for 212Pb TAT; 131Ba for 223Ra and 224Ra TAT; 123I, 124I, 131I and 209At for 211At TAT; 134Ce/134La for 227Th TAT; and 155Tb and 152Tb for 149Tb TAT.
Collapse
Affiliation(s)
- Bryce J. B. Nelson
- Department of Oncology, University of Alberta, 11560 University Ave., Edmonton, AB T6G 1Z2, Canada; (B.J.B.N.); (J.W.); (J.D.A.)
| | - John Wilson
- Department of Oncology, University of Alberta, 11560 University Ave., Edmonton, AB T6G 1Z2, Canada; (B.J.B.N.); (J.W.); (J.D.A.)
| | - Jan D. Andersson
- Department of Oncology, University of Alberta, 11560 University Ave., Edmonton, AB T6G 1Z2, Canada; (B.J.B.N.); (J.W.); (J.D.A.)
- Edmonton Radiopharmaceutical Center, Alberta Health Services, 11560 University Ave., Edmonton, AB T6G 1Z2, Canada
| | - Frank Wuest
- Department of Oncology, University of Alberta, 11560 University Ave., Edmonton, AB T6G 1Z2, Canada; (B.J.B.N.); (J.W.); (J.D.A.)
- Cancer Research Institute of Northern Alberta, University of Alberta, Edmonton, AB T6G 2E1, Canada
| |
Collapse
|
7
|
Rubira L, Deshayes E, Santoro L, Kotzki PO, Fersing C. 225Ac-Labeled Somatostatin Analogs in the Management of Neuroendocrine Tumors: From Radiochemistry to Clinic. Pharmaceutics 2023; 15:pharmaceutics15041051. [PMID: 37111537 PMCID: PMC10146019 DOI: 10.3390/pharmaceutics15041051] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 03/18/2023] [Accepted: 03/22/2023] [Indexed: 04/29/2023] Open
Abstract
The widespread use of peptide receptor radionuclide therapy (PRRT) represents a major therapeutic breakthrough in nuclear medicine, particularly since the introduction of 177Lu-radiolabeled somatostatin analogs. These radiopharmaceuticals have especially improved progression-free survival and quality of life in patients with inoperable metastatic gastroenteropancreatic neuroendocrine tumors expressing somatostatin receptors. In the case of aggressive or resistant disease, the use of somatostatin derivatives radiolabeled with an alpha-emitter could provide a promising alternative. Among the currently available alpha-emitting radioelements, actinium-225 has emerged as the most suitable candidate, especially regarding its physical and radiochemical properties. Nevertheless, preclinical and clinical studies on these radiopharmaceuticals are still few and heterogeneous, despite the growing momentum for their future use on a larger scale. In this context, this report provides a comprehensive and extensive overview of the development of 225Ac-labeled somatostatin analogs; particular emphasis is placed on the challenges associated with the production of 225Ac, its physical and radiochemical properties, as well as the place of 225Ac-DOTATOC and 225Ac-DOTATATE in the management of patients with advanced metastatic neuroendocrine tumors.
Collapse
Affiliation(s)
- Léa Rubira
- Nuclear Medicine Department, Institut Régional du Cancer de Montpellier (ICM), University Montpellier, 34090 Montpellier, France
| | - Emmanuel Deshayes
- Nuclear Medicine Department, Institut Régional du Cancer de Montpellier (ICM), University Montpellier, 34090 Montpellier, France
- Institut de Recherche en Cancérologie de Montpellier (IRCM), INSERM U1194, University Montpellier, Institut Régional du Cancer de Montpellier (ICM), 34298 Montpellier, France
| | - Lore Santoro
- Nuclear Medicine Department, Institut Régional du Cancer de Montpellier (ICM), University Montpellier, 34090 Montpellier, France
- Institut de Recherche en Cancérologie de Montpellier (IRCM), INSERM U1194, University Montpellier, Institut Régional du Cancer de Montpellier (ICM), 34298 Montpellier, France
| | - Pierre Olivier Kotzki
- Nuclear Medicine Department, Institut Régional du Cancer de Montpellier (ICM), University Montpellier, 34090 Montpellier, France
- Institut de Recherche en Cancérologie de Montpellier (IRCM), INSERM U1194, University Montpellier, Institut Régional du Cancer de Montpellier (ICM), 34298 Montpellier, France
| | - Cyril Fersing
- Nuclear Medicine Department, Institut Régional du Cancer de Montpellier (ICM), University Montpellier, 34090 Montpellier, France
- IBMM, University Montpellier, CNRS, ENSCM, 34293 Montpellier, France
| |
Collapse
|
8
|
Nelson BJB, Wilson J, Schultz MK, Andersson JD, Wuest F. High-yield cyclotron production of 203Pb using a sealed 205Tl solid target. Nucl Med Biol 2023; 116-117:108314. [PMID: 36708660 DOI: 10.1016/j.nucmedbio.2023.108314] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Revised: 12/15/2022] [Accepted: 01/02/2023] [Indexed: 01/15/2023]
Abstract
INTRODUCTION 203Pb (t1/2 = 51.9 h, 279 keV (81 %)) is a diagnostic SPECT imaging radionuclide ideally suited for theranostic applications in combination with 212Pb for targeted alpha particle therapy. Our objectives were to develop a high-yield solid target 203Pb cyclotron production route using isotopically enriched 205Tl target material and the 205Tl(p,3n)203Pb reaction as an alternative to lower energy production via the 203Tl(p,n)203Pb reaction. METHODS 250 mg 205Tl metal (99.9 % isotopic enrichment) was pressed using a hardened stainless steel die. Aluminum target discs were machined with a central depression and annulus groove. The flattened 205Tl pellet was placed into the central depression of the Al disc and a circle of indium wire was laid in the machined annulus surrounding the pellet. An aluminum foil cover was then pressed onto the target disc to create an airtight bond. Targets were irradiated at 23.3 MeV for up to 516 min on a TR-24 cyclotron at currents up to 60 μA to produce 203Pb via the 205Tl(p,3n)203Pb nuclear reaction. Following a cool-down period of >12 h, the target was removed and 205Tl dissolved in 4 M HNO3. A NEPTIS Mosaic-LC synthesis unit performed automated separation using Eichrom Pb resin, and 203Pb was eluted using 8 M HCl or 1 M NH4OAc. 205Tl was diverted to a vial for recovery in an electrolytic cell. 203Pb product radionuclidic purity was assessed by HPGe gamma spectroscopy, while elemental purity was assessed by ICP-OES. Radiolabeling and stability studies were performed with PSC, TCMC, and DOTA chelators, and 203Pb incorporation was verified by radio-TLC analysis. RESULTS Cyclotron irradiations performed at 60 μA proton beam current and 23.3 MeV (205Tl incident energy) had a 203Pb saturated yield of 4658 ± 62 MBq/μA (n = 3). Automated NEPTIS separation took <4 h from the start of target dissolution to product elution, yielding >85 % decay-corrected [203Pb]PbCl2 with a radionuclidic purity of >99.9 %. Purified [203Pb]PbCl2 yields of up to 12 GBq 203Pb were attained (15.8 GBq at EOB). The [203Pb]PbCl2 and [203Pb]Pb(OAc)2 products contained no detectable radionuclidic impurities besides 201Pb (<0.1 %), and <0.4 ppm stable Pb. 205Tl metal was recovered with a 92 % batch yield. Aliquots of 100 μL [203Pb]Pb(OAc)2 were used for radiolabeling PSC-Bn-NCS, TCMC-NCS, and DOTA-NCS chelators at pH 4.5 and 22 °C for 30 min, with maximum respective molar activities of 461 ± 30 GBq/μmol, 195 ± 37 GBq/μmol, and 83 ± 12 GBq/μmol. PSC, TCMC, and DOTA chelators exhibited >99.9 % incorporation after a 120-hour incubation in human serum at 37 °C. CONCLUSIONS Nuclear medicine centers with access to higher energy cyclotrons can produce large 203Pb activities sufficient for clinical applications, with a convenient separation technique producing highly pure [203Pb]PbCl2 or [203Pb]Pb(OAc)2 for direct radiolabeling. This represents an attractive route to produce 203Pb for diagnostic SPECT imaging alongside 212Pb targeted alpha particle therapy. ADVANCES IN KNOWLEDGE AND IMPLICATIONS FOR PATIENT CARE Our high-yield 203Pb production technique significantly enhances 203Pb production capabilities to meet the growing preclinical and clinical demand for 203Pb radiopharmaceuticals alongside 212Pb target alpha particle therapy.
Collapse
Affiliation(s)
- Bryce J B Nelson
- Department of Oncology, Cross Cancer Institute, University of Alberta, Edmonton, Alberta T6G 1Z2, Canada
| | - John Wilson
- Department of Oncology, Cross Cancer Institute, University of Alberta, Edmonton, Alberta T6G 1Z2, Canada
| | - Michael K Schultz
- Viewpoint Molecular Targeting, Inc., Coralville, IA 52241, USA; Department of Radiology, The University of Iowa, Iowa City, IA 52240, USA
| | - Jan D Andersson
- Department of Oncology, Cross Cancer Institute, University of Alberta, Edmonton, Alberta T6G 1Z2, Canada; Edmonton Radiopharmaceutical Center, Alberta Health Services, Edmonton, Alberta T6G 1Z2, Canada
| | - Frank Wuest
- Department of Oncology, Cross Cancer Institute, University of Alberta, Edmonton, Alberta T6G 1Z2, Canada; Cancer Research Institute of Northern Alberta, University of Alberta, Edmonton, Alberta T6G 2E1, Canada.
| |
Collapse
|