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Tronchin S, Forster J, Hickson K, Bezak E. Modeling the effect of daughter migration on dosimetry estimates for unlabeled actinium-225. Med Phys 2024; 51:5032-5044. [PMID: 38197481 DOI: 10.1002/mp.16917] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Revised: 12/05/2023] [Accepted: 12/13/2023] [Indexed: 01/11/2024] Open
Abstract
BACKGROUND Actinium-225 (225Ac) is an alpha emitting radionuclide which has demonstrated promising results in Targeted Alpha Therapy (TAT). A concern with 225Ac is that the decay energy can break the bond to the targeting vehicle, resulting in the release of free alpha-emitting daughter radionuclides in the body. PURPOSE The aim of this work is to develop a compartment model to describe the movement of unlabeled 225Ac in a human where the daughter isotopes of 225Ac have unique biokinetics. METHOD The ICRP Occupational Intake of Radionuclides reports were used to construct a compartment model for the 225Ac decay chain where the daughter isotopes of 225Ac are assigned their own unique transfer coefficients (TCs) between compartments. Computer simulations were performed for unlabeled 225Ac uniformly placed in the plasma and only the dose from alpha particles was considered. Absorbed doses to normal organs were determined for the liver, kidneys, bone, soft tissue, active marrow, and blood. Simulations were performed for the case when: (1) the daughters have unique biokinetics and (2) the daughters decay at the site of 225Ac. RESULTS When the daughters have unique biokinetics, the organs that receive the highest absorbed dose are the liver (male: 1466.6 mGy/MBq, female: 1885.7 mGy/MBq), bone (male: 293.6 mGy/MBq, female: 403.6 mGy/MBq) and kidneys (male: 260.8 mGy/MBq, female: 294.0 mGy/MBq). These doses were compared to the case when the daughters of 225Ac decay at the site of 225Ac. There was a 13.5% increase in kidney dose, a 0.8% decrease in liver dose, and <0.1% decrease in bone dose calculations when the daughters have unique biokinetics compared to assuming the daughters decay at the site of 225Ac. CONCLUSIONS The kidneys received a large dose estimate (260-295 mGy/MBq) as well as a considerable change in dose of +13.5% when the daughters have unique biokinetics compared to assuming the daughters decay at the site of 225Ac. Therefore, to accurately determine the kidney dose from unlabeled 225Ac in a human, the biokinetics of the daughter isotopes should be considered.
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Affiliation(s)
- Stephen Tronchin
- Department of Physics, The University of Adelaide, Adelaide, South Australia, Australia
| | - Jake Forster
- Department of Physics, The University of Adelaide, Adelaide, South Australia, Australia
- Medical Physics & Radiation Safety, South Australia Medical Imaging, Adelaide, South Australia, Australia
| | - Kevin Hickson
- Medical Physics & Radiation Safety, South Australia Medical Imaging, Adelaide, South Australia, Australia
- Allied Health & Human Performance, University of South Australia, Adelaide, South Australia, Australia
| | - Eva Bezak
- Department of Physics, The University of Adelaide, Adelaide, South Australia, Australia
- Allied Health & Human Performance, University of South Australia, Adelaide, South Australia, Australia
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Craig AJ, Taprogge J, Flux GD, Murray I. Radiation protection aspects for alpha therapies. THE QUARTERLY JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING : OFFICIAL PUBLICATION OF THE ITALIAN ASSOCIATION OF NUCLEAR MEDICINE (AIMN) [AND] THE INTERNATIONAL ASSOCIATION OF RADIOPHARMACOLOGY (IAR), [AND] SECTION OF THE SOCIETY OF... 2023; 67:4-13. [PMID: 36633588 DOI: 10.23736/s1824-4785.22.03501-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
The use of alpha emitting radiotherapeutics is increasing, with further growth expected due to a number of clinical trials currently running involving new alpha emitters. However, literature concerning radiation safety aspects of alpha emitting radionuclides is limited and most of the available literature concerns 223Ra. In general, the occupational exposure from alpha emitting radionuclides is expected to be low, as are doses to the public from external exposure. However, care must be taken to avoid skin contamination, inhalation, and ingestion. Not all alpha emitting radionuclides are identical, they often have very different associated decay chains and emissions. The decay chains and the manufacturing process should be carefully examined to identify any long-lived progeny or impurities. These may have an impact on the radiation safety processes required to limit occupational exposure and for waste management. Doses to the public must also be assessed, either arising directly from exposure to patients treated with radiotherapeutics, or via waste streams. Risk assessments should be in place when starting a new service covering all aspects of the preparation and administration, as well as any foreseeable incidents such as skin contamination or patient death, and the appropriate steps to take in these instances. It is imperative that with the increase in the use of alpha emitting radiotherapeutics more literature is published on radiation safety aspects, especially for new alpha emitting radiotherapeutics which often have very different characteristics than the currently established ones.
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Affiliation(s)
- Allison J Craig
- Joint Department of Physics, Royal Marsden NHSFT, Sutton, UK - .,The Institute of Cancer Research, London, UK -
| | - Jan Taprogge
- Joint Department of Physics, Royal Marsden NHSFT, Sutton, UK.,The Institute of Cancer Research, London, UK
| | - Glenn D Flux
- Joint Department of Physics, Royal Marsden NHSFT, Sutton, UK.,The Institute of Cancer Research, London, UK
| | - Iain Murray
- Joint Department of Physics, Royal Marsden NHSFT, Sutton, UK.,The Institute of Cancer Research, London, UK
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Gear J. Milestones in dosimetry for nuclear medicine therapy. Br J Radiol 2022; 95:20220056. [PMID: 35451857 PMCID: PMC10996314 DOI: 10.1259/bjr.20220056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Revised: 03/31/2022] [Accepted: 04/14/2022] [Indexed: 11/05/2022] Open
Abstract
Nuclear Medicine therapy has reached a critical juncture with an unprecedented number of patients being treated and an extensive list of new radiopharmaceuticals under development. Since the early applications of these treatments dosimetry has played a vital role in their development, in both aiding optimisation and enhancing safety and efficacy. To inform the future direction of this field, it is useful to reflect on the scientific and technological advances that have occurred since those early uses. In this review, we explore how dosimetry has evolved over the years and discuss why such initiatives were conceived and the importance of maintaining standards within our practise. Specific milestones and landmark publications are highlighted and a thematic review and significant outcomes during each decade are presented.
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Affiliation(s)
- Jonathan Gear
- The Joint Department of Physics, The Royal Marsden NHS
Foundation Trust & Institute of Cancer Research,
Sutton, United Kingdom
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Tronchin S, Forster JC, Hickson K, Bezak E. Dosimetry in targeted alpha therapy. A systematic review: current findings and what is needed. Phys Med Biol 2022; 67. [DOI: 10.1088/1361-6560/ac5fe0] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Accepted: 03/22/2022] [Indexed: 12/13/2022]
Abstract
Abstract
Objective. A systematic review of dosimetry in Targeted Alpha Therapy (TAT) has been performed, identifying the common issues. Approach. The systematic review was performed in accordance with the PRISMA guidelines, and the literature was searched using the Scopus and PubMed databases. Main results. From the systematic review, three key points should be considered when performing dosimetry in TAT. (1) Biodistribution/Biokinetics: the accuracy of the biodistribution data is a limit to accurate dosimetry in TAT. The biodistribution of alpha-emitting radionuclides throughout the body is difficult to image directly, with surrogate radionuclide imaging, blood/faecal sampling, and animal studies able to provide information. (2) Daughter radionuclides: the decay energy of the alpha-emissions is sufficient to break the bond to the targeting vector, resulting in a release of free daughter radionuclides in the body. Accounting for daughter radionuclide migration is essential. (3) Small-scale dosimetry and microdosimetry: due to the short path length and heterogeneous distribution of alpha-emitters at the target site, small-scale/microdosimetry are important to account for the non-uniform dose distribution in a target region, organ or cell and for assessing the biological effect of alpha-particle radiation. Significance. TAT is a form of cancer treatment capable of delivering a highly localised dose to the tumour environment while sparing the surrounding healthy tissue. Dosimetry is an important part of treatment planning and follow up. Being able to accurately predict the radiation dose to the target region and healthy organs could guide the optimal prescribed activity. Detailed dosimetry models accounting for the three points mentioned above will help give confidence in and guide the clinical application of alpha-emitting radionuclides in targeted cancer therapy.
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Sarnelli A, Belli ML, Azzali I, Loi E, Severi S, Strigari L. Alpha-Emitter Radiopharmaceuticals and External Beam Radiotherapy: A Radiobiological Model for the Combined Treatment. Cancers (Basel) 2022; 14:cancers14041077. [PMID: 35205825 PMCID: PMC8870677 DOI: 10.3390/cancers14041077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Revised: 02/15/2022] [Accepted: 02/17/2022] [Indexed: 11/16/2022] Open
Abstract
Previously published studies combined external beam radiotherapy (EBRT) treatments with different activities of 223Ra. The data of two-year overall survival (2y-OS) and neutropenia (TOX) incidence when combining EBRT and 223Ra are not homogeneous in literature. We adapted the linear-quadratic model (LQ) to 223Ra therapy using brachytherapy formalism for a mixture of radionuclides, considering the contribution of all daughter isotopes in the decay chain. A virtual cohort of patients undergoing 223Ra therapy was derived using data from the literature. The doses delivered using 223Ra and EBRT were converted into biologically equivalent doses. Fixed-effect logistic regression models were derived for both the 2y-OS and TOX and compared with available literature. Based on the literature search, four studies were identified to have reported the 223Ra injection activity levels varying from the placebo (0) to 80 kBq/kg, associated or not with EBRT. Logistic regression models revealed a dose-dependent increase in both the 2y-OS (intercept = -1.364; slope = 0.006; p-value ≤ 0.05) and TOX (-5.035; 0.018; ≤0.05) using the EBRT schedule of 8 Gy in 1 fr. Similar results were obtained for other schedules. Discrepancies between our TOX model and those derived for EBRT combined with chemotherapy are discussed. Radiobiological models allow us to estimate dose-dependent relationships, to predict the OS and TOX following combined 223Ra + EBRT treatment, which will guide future treatment optimization.
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Affiliation(s)
- Anna Sarnelli
- Medical Physics Unit, IRCCS Istituto Romagnolo per lo Studio dei Tumori (IRST) “Dino Amadori”, 47014 Meldola, Italy; (A.S.); (E.L.)
| | - Maria Luisa Belli
- Medical Physics Unit, IRCCS Istituto Romagnolo per lo Studio dei Tumori (IRST) “Dino Amadori”, 47014 Meldola, Italy; (A.S.); (E.L.)
- Correspondence:
| | - Irene Azzali
- Biostatistics and Clinical Trials Unit, IRCCS Istituto Romagnolo per lo Studio dei Tumori (IRST) “Dino Amadori”, 47014 Meldola, Italy;
| | - Emiliano Loi
- Medical Physics Unit, IRCCS Istituto Romagnolo per lo Studio dei Tumori (IRST) “Dino Amadori”, 47014 Meldola, Italy; (A.S.); (E.L.)
| | - Stefano Severi
- Nuclear Medicine Unit, IRCCS Istituto Romagnolo per lo Studio dei Tumori (IRST) “Dino Amadori”, 47014 Meldola, Italy;
| | - Lidia Strigari
- Department of Medical Physics, IRCCS Azienda Ospedaliero-Universitaria di Bologna, 40138 Bologna, Italy;
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Bastiani I, McMahon SJ, Turner P, Redmond KM, McGarry CK, Cole A, O'Sullivan JM, Prise KM, Ainsbury L, Anderson R. Dose estimation after a mixed field exposure: Radium-223 and intensity modulated radiotherapy. Nucl Med Biol 2021; 106-107:10-20. [PMID: 34968973 DOI: 10.1016/j.nucmedbio.2021.12.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Revised: 11/04/2021] [Accepted: 12/09/2021] [Indexed: 11/28/2022]
Abstract
INTRODUCTION Radium-223 dichloride ([223Ra]RaCl2), a radiopharmaceutical that delivers α-particles to regions of bone metastatic disease, has been proven to improve overall survival of men with metastatic castration resistant prostate cancer (mCRPC). mCRPC patients enrolled on the ADRRAD clinical trial are treated with a mixed field exposure comprising radium-223 (223Ra) and intensity modulated radiotherapy (IMRT). While absorbed dose estimation is an important step in the characterisation of wider systemic radiation risks in nuclear medicine, uncertainties remain for novel radiopharmaceuticals such as 223Ra. METHODS 24-Colour karyotyping was used to quantify the spectrum of chromosome aberrations in peripheral blood lymphocytes of ADRRAD patients at incremental times during their treatment. Dicentric equivalent frequencies were used in standard models for estimation of absorbed blood dose. To account for the mixed field nature of the treatment, existing models were used to determine the ratio of the component radiation types. Additionally, a new approach (M-FISHLET), based on the ratio of cells containing damage consistent with high-LET exposure (complex chromosomal exchanges) and low-LET exposure (simple exchanges), was used as a pseudo ratio for 223Ra:IMRT dose. RESULTS Total IMRT estimated doses delivered to the blood after completion of mixed radiotherapy (after 37 IMRT fractions and two [223Ra]RaCl2 injections) were in the range of 1.167 ± 0.092 and 2.148 ± 0.096 Gy (dose range across all models applied). By the last treatment cycle analysed in this study (four [223Ra]RaCl2 injections), the total absorbed 223Ra dose to the blood was estimated to be between 0.024 ± 0.027 and 0.665 ± 0.080 Gy, depending on the model used. Differences between the models were observed, with the observed dose variance coming from inter-model as opposed to inter-patient differences. The M-FISHLET model potentially overestimates the 223Ra absorbed blood dose by accounting for further PBL exposure in the vicinity of metastatic sites. CONCLUSIONS The models presented provide initial estimations of cumulative dose received during incremental IMRT fractions and [223Ra]RaCl2 injections, which will enable improved understanding of the doses received by individual patients. While the M-FISHLET method builds on a well-established technique for external exposures, further consideration is needed to evaluate this method and its use in assessing non-targeted exposure by 223Ra after its localization at bone metastatic sites.
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Affiliation(s)
- Isabella Bastiani
- Centre for Health Effects of Radiological and Chemical Agents, College of Health, Medicine and Life Sciences, Brunel University London, Kingston Lane, Uxbridge, London UB8 3PH, United Kingdom of Great Britain and Northern Ireland.
| | - Stephen J McMahon
- Patrick G. Johnston Centre for Cancer Research, Queen's University Belfast, Belfast BT9 7AE, United Kingdom of Great Britain and Northern Ireland.
| | - Philip Turner
- Patrick G. Johnston Centre for Cancer Research, Queen's University Belfast, Belfast BT9 7AE, United Kingdom of Great Britain and Northern Ireland; Northern Ireland Cancer Centre, Belfast Health and Social Care Trust, Belfast, United Kingdom of Great Britain and Northern Ireland.
| | - Kelly M Redmond
- Northern Ireland Cancer Centre, Belfast Health and Social Care Trust, Belfast, United Kingdom of Great Britain and Northern Ireland.
| | - Conor K McGarry
- Patrick G. Johnston Centre for Cancer Research, Queen's University Belfast, Belfast BT9 7AE, United Kingdom of Great Britain and Northern Ireland; Northern Ireland Cancer Centre, Belfast Health and Social Care Trust, Belfast, United Kingdom of Great Britain and Northern Ireland.
| | - Aidan Cole
- Patrick G. Johnston Centre for Cancer Research, Queen's University Belfast, Belfast BT9 7AE, United Kingdom of Great Britain and Northern Ireland; Northern Ireland Cancer Centre, Belfast Health and Social Care Trust, Belfast, United Kingdom of Great Britain and Northern Ireland.
| | - Joe M O'Sullivan
- Patrick G. Johnston Centre for Cancer Research, Queen's University Belfast, Belfast BT9 7AE, United Kingdom of Great Britain and Northern Ireland; Northern Ireland Cancer Centre, Belfast Health and Social Care Trust, Belfast, United Kingdom of Great Britain and Northern Ireland.
| | - Kevin M Prise
- Patrick G. Johnston Centre for Cancer Research, Queen's University Belfast, Belfast BT9 7AE, United Kingdom of Great Britain and Northern Ireland.
| | - Liz Ainsbury
- Centre for Radiation, Chemical & Environmental Hazards, Public Health England, Didcot OX11 0RQ, United Kingdom of Great Britain and Northern Ireland.
| | - Rhona Anderson
- Centre for Health Effects of Radiological and Chemical Agents, College of Health, Medicine and Life Sciences, Brunel University London, Kingston Lane, Uxbridge, London UB8 3PH, United Kingdom of Great Britain and Northern Ireland.
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Sgouros G, Frey E, Du Y, Hobbs R, Bolch W. Imaging and dosimetry for alpha-particle emitter radiopharmaceutical therapy: improving radiopharmaceutical therapy by looking into the black box. Eur J Nucl Med Mol Imaging 2021; 49:18-29. [PMID: 34782911 DOI: 10.1007/s00259-021-05583-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Accepted: 10/09/2021] [Indexed: 02/07/2023]
Abstract
Radiopharmaceutical therapy using α-particle emitting radionuclides (αRPT) is a novel treatment modality that delivers highly potent alpha-particles to cancer cells or their environment. We review the advantages and challenges of imaging and dosimetry in implementing αRPT for cancer patients.
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Affiliation(s)
| | - Eric Frey
- Johns Hopkins University, Baltimore, MD, USA
| | - Yong Du
- Johns Hopkins University, Baltimore, MD, USA
| | - Rob Hobbs
- Johns Hopkins University, Baltimore, MD, USA
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Andersson M, Kluge A, Meyer T, Koumarianou E, Mattsson S. IDAC-ALPHA: AN ALPHA DOSIMETRY SOFTWARE FOR NORMAL ORGANS AND TISSUES. RADIATION PROTECTION DOSIMETRY 2021; 195:327-333. [PMID: 33839784 DOI: 10.1093/rpd/ncab046] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Revised: 02/20/2021] [Accepted: 03/05/2021] [Indexed: 06/12/2023]
Abstract
Radiopharmaceuticals have been used for the treatment of various forms of cancer since the 1940s. In recent years, the advantages of alpha emitting radionuclides have emerged as a favourable treatment option. However, most alpha emitting radionuclides have long decay chains with long-lived daughter radionuclides. This leads to uncertainties in the dosimetry for normal organs and tissues, when established dosimetry models are employed. The aim of this project is to assign each progeny its own biokinetic behaviour. The novel dosimetry model was applied to 223Ra-dichloride, frequently used for the treatment of patients with metastatic bone disease from castration-resistant prostate cancer. In this dosimetry model, individual biokinetics for each daughter radionuclide was included. This resulted in a decrease in absorbed dose to bone surfaces and red marrow and increased absorbed dose to liver and kidney, when compared with dosimetry models assuming that the daughter nuclides follow the biokinetics of the parent radionuclide.
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Affiliation(s)
- M Andersson
- Department of Radiation Physics, Institute of Clinical Sciences, Sahlgrenska Cancer Center, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- Medical Radiation Physics, Department of Translational Medicine, Lund University, Skåne University Hospital, SUS Malmö, Sweden
| | - A Kluge
- ABX - CRO advanced pharmaceutical services, Dresden, Germany
| | - T Meyer
- ABX - CRO advanced pharmaceutical services, Dresden, Germany
| | - E Koumarianou
- ABX - CRO advanced pharmaceutical services, Dresden, Germany
| | - S Mattsson
- Medical Radiation Physics, Department of Translational Medicine, Lund University, Skåne University Hospital, SUS Malmö, Sweden
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Sciuto R, Rea S, Ungania S, Testa A, Dini V, Tabocchini MA, Patrono C, Soriani A, Palma V, Marconi R, Strigari L. The role of dosimetry and biological effects in metastatic castration-resistant prostate cancer (mCRPC) patients treated with 223Ra: first in human study. J Exp Clin Cancer Res 2021; 40:281. [PMID: 34488829 PMCID: PMC8420003 DOI: 10.1186/s13046-021-02056-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Accepted: 07/31/2021] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND 223Ra is currently used for treatment of metastatic castration resistant prostate cancer patients (mCRPC) bone metastases with fixed standard activity. Individualized treatments, based on adsorbed dose (AD) in target and non-target tissue, are absolutely needed to optimize efficacy while reducing toxicity of α-emitter targeted therapy. This is a pilot first in human clinical trial aimed to correlate dosimetry, clinical response and biological side effects to personalize 223Ra treatment. METHODS Out of 20 mCRPC patients who underwent standard 223Ra treatment and dosimetry, in a subset of 5 patients the AD to target and non-target tissues was correlated with clinical effects and radiation-induced chromosome damages. Before each 223Ra administrations, haematological parameters, PSA and ALP values were evaluated. Additional blood samples were obtained baseline (T0), at 7 days (T7), 30 days (T30) and 180 days (T180) to evaluate chromosome damage. After administration WB planar 223Ra images were obtained at 2-4 and 18-24 h. Treatment response and toxicity were monitored with clinical evaluation, bone scan, 18F-choline-PET/CT, PSA value and ALP while haematological parameters were evaluated weekly after 223Ra injection and 2 months after last cycle. RESULTS 1. a correlation between AD to target and clinical response was evidenced with threshold of 20 Gy as a cut-off to obtain tumor control; 2. the AD to red marrow was lower than 2 Gy in all the patients with no apparently correlation between dosimetry and clinical toxicity. 3. a high dose dependent increase of the number of dicentrics and micronuclei during the course of 223Ra therapy was observed and a linear correlation has been found between blood AD (BAD) and number of dicentrics. CONCLUSIONS This study provides some interesting preliminary evidence to be further investigated: dosimetry may be useful to identify a more appropriate 223Ra administered activity predicting AD to target tissue; a dose dependent complex chromosome damage occurs during 223Ra administration and this injury is more evident in heavily pre-treated patients; dosimetry could be used for radioprotection purpose. TRIAL REGISTRATION The pilot study has been approved from the Ethics Committee of Regina Elena National Cancer Institute (N:RS1083/18-2111).
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Affiliation(s)
- Rosa Sciuto
- Nuclear Medicine Unit, IRCCS Regina Elena National Cancer Institute, Rome, Italy
| | - Sandra Rea
- Nuclear Medicine Unit, IRCCS Regina Elena National Cancer Institute, Rome, Italy
| | - Sara Ungania
- Laboratory of Medical Physics, IRCCS Regina Elena National Cancer Institute, Rome, Italy
| | - Antonella Testa
- Division of Health Protection Technologies, ENEA Casaccia Research Center, Rome, Italy
| | - Valentina Dini
- National Center for Innovative Technologies in Public Health, Istituto Superiore di Sanità, Rome, Italy
- INFN, Rome, Italy
| | - Maria Antonella Tabocchini
- National Center for Innovative Technologies in Public Health, Istituto Superiore di Sanità, Rome, Italy
- INFN, Rome, Italy
| | - Clarice Patrono
- Division of Health Protection Technologies, ENEA Casaccia Research Center, Rome, Italy
| | - Antonella Soriani
- Laboratory of Medical Physics, IRCCS Regina Elena National Cancer Institute, Rome, Italy
| | - Valentina Palma
- Division of Health Protection Technologies, ENEA Casaccia Research Center, Rome, Italy
| | - Raffaella Marconi
- Laboratory of Medical Physics, IRCCS Regina Elena National Cancer Institute, Rome, Italy
| | - Lidia Strigari
- Laboratory of Medical Physics, IRCCS Regina Elena National Cancer Institute, Rome, Italy.
- Present address: Department of Medical Physics, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy.
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Murray I, Flux G. Applying radiobiology to clinical molecular radiotherapy. Nucl Med Biol 2021; 100-101:1-3. [PMID: 34091132 DOI: 10.1016/j.nucmedbio.2021.05.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Revised: 05/12/2021] [Accepted: 05/16/2021] [Indexed: 01/03/2023]
Affiliation(s)
- Iain Murray
- Joint Department of Physics, The Royal Marsden NHS Foundation Trust and Institute of Cancer Research, Sutton, Surrey SM2 5PT, United Kingdom.
| | - Glenn Flux
- Joint Department of Physics, The Royal Marsden NHS Foundation Trust and Institute of Cancer Research, Sutton, Surrey SM2 5PT, United Kingdom
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Corroyer-Dulmont A, Jaudet C, Frelin AM, Fantin J, Weyts K, Vallis KA, Falzone N, Sibson NR, Chérel M, Kraeber-Bodéré F, Batalla A, Bardet S, Bernaudin M, Valable S. Radioimmunotherapy for Brain Metastases: The Potential for Inflammation as a Target of Choice. Front Oncol 2021; 11:714514. [PMID: 34504791 PMCID: PMC8423367 DOI: 10.3389/fonc.2021.714514] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Accepted: 08/03/2021] [Indexed: 11/18/2022] Open
Abstract
Brain metastases (BM) are frequently detected during the follow-up of patients with malignant tumors, particularly in those with advanced disease. Despite a major progress in systemic anti-cancer treatments, the average overall survival of these patients remains limited (6 months from diagnosis). Also, cognitive decline is regularly reported especially in patients treated with whole brain external beam radiotherapy (WBRT), due to the absorbed radiation dose in healthy brain tissue. New targeted therapies, for an earlier and/or more specific treatment of the tumor and its microenvironment, are needed. Radioimmunotherapy (RIT), a combination of a radionuclide to a specific antibody, appears to be a promising tool. Inflammation, which is involved in multiple steps, including the early phase, of BM development is attractive as a relevant target for RIT. This review will focus on the (1) early biomarkers of inflammation in BM pertinent for RIT, (2) state of the art studies on RIT for BM, and (3) the importance of dosimetry to RIT in BM. These two last points will be addressed in comparison to the conventional EBRT treatment, particularly with respect to the balance between tumor control and healthy tissue complications. Finally, because new diagnostic imaging techniques show a potential for the detection of BM at an early stage of the disease, we focus particularly on this therapeutic window.
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Affiliation(s)
- Aurélien Corroyer-Dulmont
- Medical Physics Department, CLCC François Baclesse, Caen, France
- Normandie Univ, UNICAEN, CEA, CNRS, ISTCT/CERVOxy Group, GIP CYCERON, Caen, France
| | - Cyril Jaudet
- Medical Physics Department, CLCC François Baclesse, Caen, France
| | - Anne-Marie Frelin
- Grand accélérateur National d’Ions Lourds (GANIL), CEA/DRF-CNRS/IN2P3, Caen, France
| | - Jade Fantin
- Normandie Univ, UNICAEN, CEA, CNRS, ISTCT/CERVOxy Group, GIP CYCERON, Caen, France
| | - Kathleen Weyts
- Nuclear Medicine Department, CLCC François Baclesse, Caen, France
| | - Katherine A. Vallis
- Medical Research Council, Department of Oncology, Oxford Institute for Radiation Oncology, University of Oxford, Oxford, United Kingdom
| | | | - Nicola R. Sibson
- Medical Research Council, Department of Oncology, Oxford Institute for Radiation Oncology, University of Oxford, Oxford, United Kingdom
| | - Michel Chérel
- Team 13-Nuclear Oncology, CRCINA, INSERM, CNRS, Nantes University, Nantes, France
| | - Françoise Kraeber-Bodéré
- Team 13-Nuclear Oncology, CRCINA, INSERM, CNRS, Nantes University, Nantes, France
- Nuclear Medicine Department, University Hospital, Nantes, France
| | - Alain Batalla
- Medical Physics Department, CLCC François Baclesse, Caen, France
| | - Stéphane Bardet
- Nuclear Medicine Department, CLCC François Baclesse, Caen, France
| | - Myriam Bernaudin
- Normandie Univ, UNICAEN, CEA, CNRS, ISTCT/CERVOxy Group, GIP CYCERON, Caen, France
| | - Samuel Valable
- Normandie Univ, UNICAEN, CEA, CNRS, ISTCT/CERVOxy Group, GIP CYCERON, Caen, France
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Höllriegl V, Petoussi-Henss N, Hürkamp K, Ocampo Ramos JC, Li WB. Radiopharmacokinetic modelling and radiation dose assessment of 223Ra used for treatment of metastatic castration-resistant prostate cancer. EJNMMI Phys 2021; 8:44. [PMID: 34076794 PMCID: PMC8172819 DOI: 10.1186/s40658-021-00388-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Accepted: 05/12/2021] [Indexed: 12/09/2022] Open
Abstract
PURPOSE Ra-223 dichloride (223Ra, Xofigo®) is used for treatment of patients suffering from castration-resistant metastatic prostate cancer. The objective of this work was to apply the most recent biokinetic model for radium and its progeny to show their radiopharmacokinetic behaviour. Organ absorbed doses after intravenous injection of 223Ra were estimated and compared to clinical data and data of an earlier modelling study. METHODS The most recent systemic biokinetic model of 223Ra and its progeny, developed by the International Commission on Radiological Protection (ICRP), as well as the ICRP human alimentary tract model were applied for the radiopharmacokinetic modelling of Xofigo® biodistribution in patients after bolus administration. Independent kinetics were assumed for the progeny of 223Ra. The time activity curves for 223Ra were modelled and the time integrated activity coefficients, [Formula: see text] in the source regions for each progeny were determined. For estimating the organ absorbed doses, the Specific Absorbed Fractions (SAF) and dosimetric framework of ICRP were used together with the aforementioned [Formula: see text] values. RESULTS The distribution of 223Ra after injection showed a rapid plasma clearance and a low urinary excretion. Main elimination was via faeces. Bone retention was found to be about 30% at 4 h post-injection. Similar tendencies were observed in clinical trials of other authors. The highest absorbed dose coefficients were found for bone endosteum, liver and red marrow, followed by kidneys and colon. CONCLUSION The biokinetic modelling of 223Ra and its progeny may help to predict their distributions in patients after administration of Xofigo®. The organ dose coefficients of this work showed some variation to the values reported from clinical studies and an earlier compartmental modelling study. The dose to the bone endosteum was found to be lower by a factor of ca. 3 than previously estimated.
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Affiliation(s)
- Vera Höllriegl
- Institute of Radiation Medicine, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstädter Landstraße 1, 85764, Neuherberg, Germany
| | - Nina Petoussi-Henss
- Institute of Radiation Medicine, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstädter Landstraße 1, 85764, Neuherberg, Germany
| | - Kerstin Hürkamp
- Institute of Radiation Medicine, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstädter Landstraße 1, 85764, Neuherberg, Germany
| | - Juan Camilo Ocampo Ramos
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, 1250 First Avenue, New York, NY, 10065, USA
| | - Wei Bo Li
- Institute of Radiation Medicine, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstädter Landstraße 1, 85764, Neuherberg, Germany.
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Marques IA, Abrantes AM, Pires AS, Neves AR, Caramelo FJ, Rodrigues T, Matafome P, Tavares-da-Silva E, Gonçalves AC, Pereira CC, Teixeira JP, Seiça R, Costa G, Figueiredo A, Botelho MF. Kinetics of radium-223 and its effects on survival, proliferation and DNA damage in lymph-node and bone metastatic prostate cancer cell lines. Int J Radiat Biol 2021; 97:714-726. [PMID: 33764249 DOI: 10.1080/09553002.2021.1906462] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 02/15/2021] [Accepted: 03/15/2021] [Indexed: 12/24/2022]
Abstract
BACKGROUND Metastatic castration-resistant prostate cancer (mCRPC) is associated with a very unfavorable prognosis. At this advanced stage of the disease, there are several therapeutic strategies approved in recent times, being one of them Radium-223 dichloride (Radium-223). However, its mechanisms of action and the process that conducts to cell death are not fully understood. Given this, our main goal is to characterize the radiobiological effects induced by Radium-223 and to evaluate its kinetics on metastatic Prostate Cancer (mPCa) cells. MATERIALS AND METHODS In vitro studies were conducted using two mPCa cell lines, the LNCaP and PC3, the first being derived from lymph node metastasis and the second from bone metastasis. Kinetic studies were conducted to access the capacity of these cell lines to uptake, retain and internalize the Radium-223. For the assessment of radiobiological effects, cells were first exposed to different doses of Radium-223 and the clonogenic assay was done to evaluate cell survival and to determine lethal doses (LD50). Then, the effects were also evaluated in terms of proliferation, oxidative stress, morphological changes and cell damage. RESULTS Radium-223 is uptaken by mPCa cells and reaches the nucleus, where it is retained over time. Irradiation decreases cell survival and proliferation, with LNCaP cells (LD50 = 1.73mGy) being more radiosensitive than PC3 cells (LD50 = 4.20mGy). Irradiated cells showed morphological changes usually associated with apoptosis and a dose-dependent increase in DNA damage. Moreover, activation of cell cycle checkpoints occurs through ATM/CHK2 pathway, which is involved in cell cycle arrest and cell death. CONCLUSIONS The cytotoxic and anti-proliferative effects on both cell lines showed that Radium-223 can decrease the aggressiveness of tumor cells by decreasing the cell survival and proliferation and, also, by increasing the DNA damage. The similar results observed in both cell lines indicated that Radium-223 may have the potential to be used as a therapeutic option also for mCRPC patients with lymph node metastasis. The activation of DNA Damage Response pathways allows the possibility to understand the importance of these checkpoints as targets for new combined therapies.
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Affiliation(s)
- Inês A Marques
- University of Coimbra, Coimbra Institute for Clinical and Biomedical Research (iCBR) area of Environment Genetics and Oncobiology (CIMAGO), Biophysics Institute of Faculty of Medicine, Coimbra, Portugal
- Center for Innovative Biomedicine and Biotechnology (CIBB), Coimbra, Portugal
- Clinical Academic Center of Coimbra (CACC), Coimbra, Portugal
- University of Coimbra, Faculty of Pharmacy, Coimbra, Portugal
| | - Ana M Abrantes
- University of Coimbra, Coimbra Institute for Clinical and Biomedical Research (iCBR) area of Environment Genetics and Oncobiology (CIMAGO), Biophysics Institute of Faculty of Medicine, Coimbra, Portugal
- Center for Innovative Biomedicine and Biotechnology (CIBB), Coimbra, Portugal
- Clinical Academic Center of Coimbra (CACC), Coimbra, Portugal
| | - Ana S Pires
- University of Coimbra, Coimbra Institute for Clinical and Biomedical Research (iCBR) area of Environment Genetics and Oncobiology (CIMAGO), Biophysics Institute of Faculty of Medicine, Coimbra, Portugal
- Center for Innovative Biomedicine and Biotechnology (CIBB), Coimbra, Portugal
- Clinical Academic Center of Coimbra (CACC), Coimbra, Portugal
| | - Ana R Neves
- University of Coimbra, Coimbra Institute for Clinical and Biomedical Research (iCBR) area of Environment Genetics and Oncobiology (CIMAGO), Biophysics Institute of Faculty of Medicine, Coimbra, Portugal
- Project Development Office, Department of Mathematics and Computer Science, Eindhoven University of Technology (TU/e), Eindhoven, The Netherlands
| | - Francisco J Caramelo
- Clinical Academic Center of Coimbra (CACC), Coimbra, Portugal
- University of Coimbra, Coimbra Institute for Clinical and Biomedical Research (iCBR), Laboratory of Biostatistics and Medical Informatics of Faculty of Medicine, Coimbra, Portugal
| | - Tiago Rodrigues
- Center for Innovative Biomedicine and Biotechnology (CIBB), Coimbra, Portugal
- Clinical Academic Center of Coimbra (CACC), Coimbra, Portugal
- University of Coimbra, Coimbra Institute for Clinical and Biomedical Research (iCBR), Laboratory of Physiology of Faculty of Medicine, Coimbra, Portugal
| | - Paulo Matafome
- Center for Innovative Biomedicine and Biotechnology (CIBB), Coimbra, Portugal
- Clinical Academic Center of Coimbra (CACC), Coimbra, Portugal
- University of Coimbra, Coimbra Institute for Clinical and Biomedical Research (iCBR), Laboratory of Physiology of Faculty of Medicine, Coimbra, Portugal
| | - Edgar Tavares-da-Silva
- University of Coimbra, Coimbra Institute for Clinical and Biomedical Research (iCBR) area of Environment Genetics and Oncobiology (CIMAGO), Biophysics Institute of Faculty of Medicine, Coimbra, Portugal
- Center for Innovative Biomedicine and Biotechnology (CIBB), Coimbra, Portugal
- Clinical Academic Center of Coimbra (CACC), Coimbra, Portugal
- Centro Hospitalar e Universitário de Coimbra (CHUC), Department of Urology and Renal Transplantation, Coimbra, Portugal
| | - Ana C Gonçalves
- Center for Innovative Biomedicine and Biotechnology (CIBB), Coimbra, Portugal
- Clinical Academic Center of Coimbra (CACC), Coimbra, Portugal
- University of Coimbra, Coimbra Institute for Clinical and Biomedical Research (iCBR), Laboratory of Oncobiology and Hematology and University Clinic of Hematology of Faculty of Medicine, Coimbra, Portugal
| | - Cristiana C Pereira
- National Institute of Health, Environmental Health Department, Porto, Portugal
- EPIUnit - Instituto de Saúde Pública, Universidade do Porto, Porto, Portugal
| | - João P Teixeira
- National Institute of Health, Environmental Health Department, Porto, Portugal
- EPIUnit - Instituto de Saúde Pública, Universidade do Porto, Porto, Portugal
| | - Raquel Seiça
- Center for Innovative Biomedicine and Biotechnology (CIBB), Coimbra, Portugal
- Clinical Academic Center of Coimbra (CACC), Coimbra, Portugal
- University of Coimbra, Coimbra Institute for Clinical and Biomedical Research (iCBR), Laboratory of Physiology of Faculty of Medicine, Coimbra, Portugal
| | - Grancinda Costa
- Centro Hospitalar e Universitário de Coimbra (CHUC), Department of Nuclear Medicine, Coimbra, Portugal
| | - Arnaldo Figueiredo
- University of Coimbra, Coimbra Institute for Clinical and Biomedical Research (iCBR) area of Environment Genetics and Oncobiology (CIMAGO), Biophysics Institute of Faculty of Medicine, Coimbra, Portugal
- Center for Innovative Biomedicine and Biotechnology (CIBB), Coimbra, Portugal
- Clinical Academic Center of Coimbra (CACC), Coimbra, Portugal
- Centro Hospitalar e Universitário de Coimbra (CHUC), Department of Urology and Renal Transplantation, Coimbra, Portugal
| | - Maria F Botelho
- University of Coimbra, Coimbra Institute for Clinical and Biomedical Research (iCBR) area of Environment Genetics and Oncobiology (CIMAGO), Biophysics Institute of Faculty of Medicine, Coimbra, Portugal
- Center for Innovative Biomedicine and Biotechnology (CIBB), Coimbra, Portugal
- Clinical Academic Center of Coimbra (CACC), Coimbra, Portugal
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Abstract
As a single organ distributed diffusely throughout the body, bones represent both a unique challenge and unique opportunity for the treatment of symptomatic metastatic disease. While the multifocality of bone metastases often prevents effective complete treatment with focal radiotherapy, the similar pathophysiology of these diffuse sites of disease opens the door to targeted systemic therapy. The relatively rapid dose fall-off from beta- or alpha-emitting particles, if correctly and reliably targeted to osseous metastases, might reduce tumor burden and enhance pain control or improve survival. Radioisotopes have thus been studied keenly with the first generation of primarily beta-emitting radioisotopes, strontium-89 and samarium-153, which reached early FDA approval based on successful endpoints of pain control. More recently, an alpha-emitting therapy, radium-223, has demonstrated a successful endpoint of improved overall survival in patients with a burden of symptomatic, metastatic castrate-resistant prostate cancer (mCRPC) confined to the bones. With this discovery, an additional survival-improving tool beyond systemic and hormonal agents was added to the treatment arsenal for mCRPC for suitable candidates. With an improved understanding of the optimization of hormonal and systemic therapies in the context of mCRPC, there is lingering uncertainty regarding the safety and efficacy of combinatorial use of alpha and beta-emitting therapies with the current generation of systemic agents. In this narrative review, we will highlight the current understanding of the relative utility and clinical paradigms involving alpha- and beta-emitting radioisotopes. We discuss fundamental mechanisms for antineoplastic activity, initial clinical trials validating their use, the use of concurrent antiresorptive therapies to provide bone protection, and ongoing clinical trials targeted at best utilization of these agents in the broader context of mCRPC treatment.
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Affiliation(s)
- Andrew W Smith
- Departments of Radiation Oncology, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Benjamin A Greenberger
- Sidney Kimmel Medical College & Cancer Center at Thomas Jefferson University, Philadelphia, PA
| | - Robert B Den
- Sidney Kimmel Medical College & Cancer Center at Thomas Jefferson University, Philadelphia, PA
| | - Richard G Stock
- Departments of Radiation Oncology, Icahn School of Medicine at Mount Sinai, New York, NY..
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Ogawa K, Higashi T, Mishiro K, Wakabayashi H, Shiba K, Odani A, Kinuya S. Decreasing undesirable absorbed radiation to the intestine after administration of radium-223 dichloride for treatment of bone metastases. Sci Rep 2020; 10:11917. [PMID: 32681007 PMCID: PMC7368038 DOI: 10.1038/s41598-020-68846-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Accepted: 07/02/2020] [Indexed: 11/08/2022] Open
Abstract
[223Ra]RaCl2 is the first alpha-particle emitting radiopharmaceutical to be used for castration-resistant prostate cancer patients with bone metastases because of its excellent therapeutic effects. [223Ra]RaCl2 is excreted via the intestine into feces, and some is absorbed from the intestine into the blood, which may be undesirable in terms of the exposure to radiation. Recently, we showed that a complex of myo-inositol-hexakisphosphate (InsP6) with zinc is a useful decorporation agent against radiostrontium. In this study, we hypothesized that Zn-InsP6 could bind to not only strontium but also to radium, and could inhibit the absorption of radium from the intestine. In in vitro binding experiments, Zn-InsP6 showed a high binding affinity for radium. In in vivo biodistribution experiments by intravenous injection of [223Ra]RaCl2 after treatment of Zn-InsP6, mice treated with Zn-InsP6 showed significantly lower bone accumulation of radioactivity (34.82 ± 1.83%Dose/g) than the mice in the non-treatment control group (40.30 ± 2.78%Dose/g) at 48 h postinjection. These results indicate that Zn-InsP6 bound radium in the intestine and inhibited the absorption of radium into the blood. Therefore, the insoluble Zn-InsP6 complex has high potential to decrease the side effects of [223Ra]RaCl2.
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Affiliation(s)
- Kazuma Ogawa
- Institute for Frontier Science Initiative, Kanazawa University, Kakuma-machi, Kanazawa, 920-1192, Japan.
- Graduate School of Medical Sciences, Kanazawa University, Kakuma-machi, Kanazawa, 920-1192, Japan.
| | - Takuma Higashi
- Graduate School of Medical Sciences, Kanazawa University, Kakuma-machi, Kanazawa, 920-1192, Japan
| | - Kenji Mishiro
- Institute for Frontier Science Initiative, Kanazawa University, Kakuma-machi, Kanazawa, 920-1192, Japan
| | | | - Kazuhiro Shiba
- Advanced Science Research Center, Kanazawa University, Takara-machi, Kanazawa, 920-8640, Japan
| | - Akira Odani
- Graduate School of Medical Sciences, Kanazawa University, Kakuma-machi, Kanazawa, 920-1192, Japan
| | - Seigo Kinuya
- Graduate School of Medical Sciences, Kanazawa University, Kakuma-machi, Kanazawa, 920-1192, Japan
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Guerra Liberal FDC, O'Sullivan JM, McMahon SJ, Prise KM. Targeted Alpha Therapy: Current Clinical Applications. Cancer Biother Radiopharm 2020; 35:404-417. [PMID: 32552031 DOI: 10.1089/cbr.2020.3576] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
α-Emitting radionuclides have been approved for cancer treatment since 2013, with increasing degrees of success. Despite this clinical utility, little is known regarding the mechanisms of action of α particles in this setting, and accurate assessments of the dosimetry underpinning their effectiveness are lacking. However, targeted alpha therapy (TAT) is gaining more attention as new targets, synthetic chemistry approaches, and α particle emitters are identified, constructed, developed, and realized. From a radiobiological perspective, α particles are more effective at killing cells compared to low linear energy transfer radiation. Also, from these direct effects, it is now evident from preclinical and clinical data that α emitters are capable of both producing effects in nonirradiated bystander cells and stimulating the immune system, extending the biological effects of TAT beyond the range of α particles. The short range of α particles makes them a potent tool to irradiate single-cell lesions or treat solid tumors by minimizing unwanted irradiation of normal tissue surrounding the cancer cells, assuming a high specificity of the radiopharmaceutical and good stability of its chemical bonds. Clinical approval of 223RaCl2 in 2013 was a major milestone in the widespread application of TAT as a safe and effective strategy for cancer treatment. In addition, 225Ac-prostate specific membrane antigen treatment benefit in metastatic castrate-resistant prostate cancer patients, refractory to standard therapies, is another game-changing piece in the short history of TAT clinical application. Clinical applications of TAT are growing with different radionuclides and combination therapies, and in different clinical settings. Despite the remarkable advances in TAT dosimetry and imaging, it has not yet been used to its full potential. Labeled 227Th and 225Ac appear to be promising candidates and could represent the next generation of agents able to extend patient survival in several clinical scenarios.
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Affiliation(s)
- Francisco D C Guerra Liberal
- The Patrick G Johnston Centre for Cancer Research, Queen's University Belfast, Belfast, United Kingdom.,Faculdade de Ciências e Tenclonogia, Universidade Nova de Lisboa, Caparica, Portugal
| | - Joe M O'Sullivan
- The Patrick G Johnston Centre for Cancer Research, Queen's University Belfast, Belfast, United Kingdom.,Clinical Oncology, Northern Ireland Cancer Centre, Belfast Health and Social Care Trust, Belfast, United Kingdom
| | - Stephen J McMahon
- The Patrick G Johnston Centre for Cancer Research, Queen's University Belfast, Belfast, United Kingdom
| | - Kevin M Prise
- The Patrick G Johnston Centre for Cancer Research, Queen's University Belfast, Belfast, United Kingdom
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