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Reis A, Sampaio C, Sousa W, Aguiar L, Bertelli L. Key topics for making decisions on decorporation terapies. RADIATION PROTECTION DOSIMETRY 2024; 200:707-714. [PMID: 38678315 DOI: 10.1093/rpd/ncae097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Revised: 01/19/2024] [Accepted: 04/08/2024] [Indexed: 04/29/2024]
Abstract
Decorporation therapies increase the excretion of the incorporated material and therefore may reduce the probability of the occurrence of stochastic effects and may avoid deterministic effects in persons internally contaminated with radionuclides. The decision to initiate decorporation therapy should consider the effects of treatment in relation to the benefit provided. The literature presents threshold values above which treatment is recommended. The objective of this work is to collect and summarize recommendations on decorporation therapy. Ten key topics are presented for consideration by a multidisciplinary team when assessing the risk-benefit balance for performing decorporation therapy.
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Affiliation(s)
- Arlene Reis
- Institute of Radiation Protection and Dosimetry (IRD), Division of Dosimetry and Radiation Protection, Barra da Tijuca, RJ 22783-127, Brazil
| | - Camilla Sampaio
- Institute of Radiation Protection and Dosimetry (IRD), Division of Dosimetry and Radiation Protection, Barra da Tijuca, RJ 22783-127, Brazil
| | - Wanderson Sousa
- Institute of Radiation Protection and Dosimetry (IRD), Division of Dosimetry and Radiation Protection, Barra da Tijuca, RJ 22783-127, Brazil
| | - Laís Aguiar
- Institute of Radiation Protection and Dosimetry (IRD), Division of Dosimetry and Radiation Protection, Barra da Tijuca, RJ 22783-127, Brazil
| | - Luiz Bertelli
- L Bertelli & Associates, 6190 S Eagle Nest Drive Murray, UT, 84123, USA
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Dumit S, Miller G, Grémy O, Poudel D, Bertelli L, Klumpp JA. Chelation Modeling of a Plutonium-238 Inhalation Incident Treated with Delayed DTPA. Radiat Res 2023; 200:577-586. [PMID: 37956868 DOI: 10.1667/rade-23-00135.1] [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: 07/12/2023] [Accepted: 10/14/2023] [Indexed: 11/15/2023]
Abstract
This work describes an analysis, using a previously established chelation model, of the bioassay data collected from a worker who received delayed chelation therapy following a plutonium-238 inhalation. The details of the case have already been described in two publications. The individual was treated with Ca-DTPA via multiple intravenous injections and then nebulizations beginning several months after the intake and continuing for four years. The exact date and circumstances of the intake are unknown. However, interviews with the worker suggested that the intake occurred via inhalation of a soluble plutonium compound. The worker provided daily urine and fecal bioassay samples throughout the chelation treatment protocol, including samples collected before, during, and after the administration of Ca-DTPA. Unlike the previous two publications presenting this case, the current analysis explicitly models the combined biokinetics of the plutonium-DTPA chelate. Using the previously established chelation model, it was possible to fit the data through optimizing only the intake (day and magnitude), solubility, and absorbed fraction of nebulized Ca-DTPA. This work supports the hypothesis that the efficacy of the delayed chelation treatment observed in this case results mainly from chelation of cell-internalized plutonium by Ca-DTPA (intracellular chelation). It also demonstrates the validity of the previously established chelation model. As the bioassay data were modified to ensure data anonymization, the calculation of the "true" committed effective dose was not possible. However, the treatment-induced dose inhibition (in percentage) was calculated.
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Affiliation(s)
- Sara Dumit
- Los Alamos National Laboratory (LANL), Radiation Protection Division, Los Alamos, New Mexico 87545
| | - Guthrie Miller
- Unaffiliated (retired from Los Alamos National Laboratory), Santa Fe, New Mexico
| | - Olivier Grémy
- Commissariat à l'Energie Atomique et aux Energies Alternatives (CEA), Direction de la Recherche Fondamentale, Institut de Biologie François Jacob, Université Paris-Saclay, Fontenay-aux-Roses, France
| | - Deepesh Poudel
- Los Alamos National Laboratory (LANL), Radiation Protection Division, Los Alamos, New Mexico 87545
| | | | - John A Klumpp
- Los Alamos National Laboratory (LANL), Radiation Protection Division, Los Alamos, New Mexico 87545
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Kastl M, Grémy O, Lamart S, Giussani A, Li WB, Hoeschen C. Modelling DTPA therapy following Am contamination in rats. RADIATION AND ENVIRONMENTAL BIOPHYSICS 2023; 62:483-495. [PMID: 37831188 PMCID: PMC10628027 DOI: 10.1007/s00411-023-01046-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Accepted: 09/25/2023] [Indexed: 10/14/2023]
Abstract
A major challenge in modelling the decorporation of actinides (An), such as americium (Am), with DTPA (diethylenetriaminepentaacetic acid) is the fact that standard biokinetic models become inadequate for assessing radionuclide intake and estimating the resulting dose, as DTPA perturbs the regular biokinetics of the radionuclide. At present, most attempts existing in the literature are empirical and developed mainly for the interpretation of one or a limited number of specific incorporation cases. Recently, several approaches have been presented with the aim of developing a generic model, one of which reported the unperturbed biokinetics of plutonium (Pu), the chelation process and the behaviour of the chelated compound An-DTPA with a single model structure. The aim of the approach described in this present work is the development of a generic model that is able to describe the biokinetics of Am, DTPA and the chelate Am-DTPA simultaneously. Since accidental intakes in humans present many unknowns and large uncertainties, data from controlled studies in animals were used. In these studies, different amounts of DTPA were administered at different times after contamination with known quantities of Am. To account for the enhancement of faecal excretion and reduction in liver retention, DTPA is assumed to chelate Am not only in extracellular fluids, but also in hepatocytes. A good agreement was found between the predictions of the proposed model and the experimental results for urinary and faecal excretion and accumulation and retention in the liver. However, the decorporation from the skeletal compartment could not be reproduced satisfactorily under these simple assumptions.
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Affiliation(s)
- Manuel Kastl
- Institute of Radiation Medicine, Helmholtz Center Munich, German Research Center for Environmental Health, Neuherberg, Germany.
| | - Olivier Grémy
- Laboratoire de Radio Toxicologie, CEA, Université de Paris-Saclay, Arpajon, France
| | - Stephanie Lamart
- Laboratoire de Radio Toxicologie, CEA, Université de Paris-Saclay, Arpajon, France
- Laboratoire d'Evaluation de la Dose Interne, Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PSE-SANTE/SDOS/LEDI, Fontenay-aux-Roses, France
| | - Augusto Giussani
- Division of Medical and Occupational Radiation Protection, Federal Office for Radiation Protection, Oberschleißheim, Germany
| | - Wei Bo Li
- Institute of Radiation Medicine, Helmholtz Center Munich, German Research Center for Environmental Health, Neuherberg, Germany
- Division of Medical and Occupational Radiation Protection, Federal Office for Radiation Protection, Oberschleißheim, Germany
| | - Christoph Hoeschen
- Institut für Medizintechnik, Otto-Von-Guericke University Magdeburg, Magdeburg, Germany
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Grémy O, Blanchin N, Miccoli L. Excretion of Pu-238 during Long-term Chelation Therapy by Repeated DTPA Inhalation. HEALTH PHYSICS 2022; 123:197-207. [PMID: 35613373 DOI: 10.1097/hp.0000000000001584] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
ABSTRACT An individual underwent an extensive diethylenetriaminepentaacetate (DTPA) chelation therapy that started several months after plutonium incorporation, most likely by inhalation of a soluble compound. After receiving multiple intravenous infusions of DTPA, the patient continued the treatment by pulmonary delivery of aerosolized DTPA. The purpose of the present work is to provide and discuss the bioassay data obtained during the DTPA aerosol therapy and compare them with those under the DTPA infusion therapy that have been largely interpreted elsewhere. As with DTPA given intravenously, each delayed DTPA inhalation increased the clearance of plutonium not only in urine but also in feces, thus demonstrating the ability to remove plutonium retained by extrapulmonary tissues. Also, the slow decline of increased plutonium urinary elimination together with enhanced fecal excretion are two features coherent with the contribution of intracellular chelation to overall decorporation. The therapeutic benefit of DTPA inhalation appeared lower than with DTPA infusion, most likely due to a lower amount of DTPA reaching the systemic compartments where plutonium chelation predominates. The results suggest that DTPA administration through aerosol could be an alternative to the invasive procedure using a needle, i.e., intravenous injection/infusion, when protracted decorporation therapy is needed following transuranic internalization. Indeed, the patient may be more inclined to undergo a chelation treatment for a longer period because taking DTPA by inhalation may make it less cumbersome and painful.
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Affiliation(s)
- Olivier Grémy
- CEA, Direction de la Recherche Fondamentale, Institut de Biologie François Jacob, Université Paris-Saclay, Fontenay-aux-Roses, France
| | - Nicolas Blanchin
- CEA, Service de Santé au Travail, Saint-Paul-Lez-Durance, France
| | - Laurent Miccoli
- CEA, Direction de la Recherche Fondamentale, Institut de Biologie François Jacob, Université Paris-Saclay, Fontenay-aux-Roses, France
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Lai EPC, Li C. Actinide Decorporation: A Review on Chelation Chemistry and Nanocarriers for Pulmonary Administration. Radiat Res 2022; 198:430-443. [PMID: 35943882 DOI: 10.1667/rade-21-00004.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2021] [Accepted: 07/05/2022] [Indexed: 11/03/2022]
Abstract
Chelation is considered the best method for detoxification by promoting excretion of actinides (Am, Np, Pu, Th, U) from the human body after internal contamination. Chemical agents that possess carboxylic acid or hydroxypyridinonate groups play a vital role in actinide decorporation. In this review article, we provide considerable background details on the chelation chemistry of actinides with an aim to formulate better decorporation agents. Nanocarriers for pulmonary delivery represent an exciting prospect in the development of novel therapies for actinide decorporation that both reduce toxic side effects of the agent and improve its retention in the body. Recent studies have demonstrated the benefits of using a nebulizer or an inhaler to administer chelating agents for the decorporation of actinides. Effective chelation therapy with large groups of internally contaminated people can be a challenge unless both the agent and the nanocarrier are readily available from strategic national stockpiles for radiological or nuclear emergencies. Sunflower lecithin is particularly adept at alleviating the burden of administration when used to form liposomes as a nanocarrier for pulmonary delivery of diethylenetriamine-pentaacetic acid (DTPA) or hydroxypyridinone (HOPO). Better physiologically-based pharmacokinetic models must be developed for each agent in order to minimize the frequency of multiple doses that can overload the emergency response operations.
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Affiliation(s)
- Edward P C Lai
- Ottawa-Carleton Chemistry Institute, Department of Chemistry, Carleton University, Ottawa, ON K1S 5B6, Canada
| | - Chunsheng Li
- Radiation Protection Bureau, Health Canada, Ottawa, ON K1A 1C1, Canada
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