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Bourhis J, Sozzi WJ, Jorge PG, Gaide O, Bailat C, Duclos F, Patin D, Ozsahin M, Bochud F, Germond JF, Moeckli R, Vozenin MC. Treatment of a first patient with FLASH-radiotherapy. Radiother Oncol 2019; 139:18-22. [PMID: 31303340 DOI: 10.1016/j.radonc.2019.06.019] [Citation(s) in RCA: 304] [Impact Index Per Article: 60.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Revised: 06/12/2019] [Accepted: 06/14/2019] [Indexed: 01/16/2023]
Abstract
BACKGROUND When compared to conventional radiotherapy (RT) in pre-clinical studies, FLASH-RT was shown to reproducibly spare normal tissues, while preserving the anti-tumor activity. This marked increase of the differential effect between normal tissues and tumors prompted its clinical translation. In this context, we present here the treatment of a first patient with FLASH-RT. MATERIAL & METHODS A 75-year-old patient presented with a multiresistant CD30+ T-cell cutaneous lymphoma disseminated throughout the whole skin surface. Localized skin RT has been previously used over 110 times for various ulcerative and/or painful cutaneous lesions progressing despite systemic treatments. However, the tolerance of these RT was generally poor, and it was hypothesized that FLASH-RT could offer an equivalent tumor control probability, while being less toxic for the skin. This treatment was given to a 3.5-cm diameter skin tumor with a 5.6-MeV linac specifically designed for FLASH-RT. The prescribed dose to the PTV was 15 Gy, in 90 ms. Redundant dosimetric measurements were performed with GafChromic films and alanine, to check the consistency between the prescribed and the delivered doses. RESULTS At 3 weeks, i.e. at the peak of the reactions, a grade 1 epithelitis (CTCAE v 5.0) along with a transient grade 1 oedema (CTCAE v5.0) in soft tissues surrounding the tumor were observed. Clinical examination was consistent with the optical coherence tomography showing no decrease of the thickness of the epidermis and no disruption at the basal membrane with limited increase of the vascularization. In parallel, the tumor response was rapid, complete, and durable with a short follow-up of 5 months. These observations, both on normal skin and on the tumor, were promising and prompt to further clinical evaluation of FLASH-RT. CONCLUSION This first FLASH-RT treatment was feasible and safe with a favorable outcome both on normal skin and the tumor.
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Affiliation(s)
- Jean Bourhis
- Department of Radiation Oncology, Lausanne University Hospital and University of Lausanne, Switzerland; Radiation Oncology Laboratory, Department of Radiation Oncology. Lausanne University Hospital and University of Lausanne, Switzerland.
| | - Wendy Jeanneret Sozzi
- Department of Radiation Oncology, Lausanne University Hospital and University of Lausanne, Switzerland
| | - Patrik Gonçalves Jorge
- Department of Radiation Oncology, Lausanne University Hospital and University of Lausanne, Switzerland; Radiation Oncology Laboratory, Department of Radiation Oncology. Lausanne University Hospital and University of Lausanne, Switzerland; Institute of Radiation Physics, Lausanne University Hospital and University of Lausanne, Switzerland
| | - Olivier Gaide
- Department of Dermatology, Lausanne University Hospital and University of Lausanne, Switzerland
| | - Claude Bailat
- Institute of Radiation Physics, Lausanne University Hospital and University of Lausanne, Switzerland
| | - Fréderic Duclos
- Department of Radiation Oncology, Lausanne University Hospital and University of Lausanne, Switzerland
| | - David Patin
- Department of Radiation Oncology, Lausanne University Hospital and University of Lausanne, Switzerland
| | - Mahmut Ozsahin
- Department of Radiation Oncology, Lausanne University Hospital and University of Lausanne, Switzerland
| | - François Bochud
- Institute of Radiation Physics, Lausanne University Hospital and University of Lausanne, Switzerland
| | - Jean-François Germond
- Institute of Radiation Physics, Lausanne University Hospital and University of Lausanne, Switzerland
| | - Raphaël Moeckli
- Institute of Radiation Physics, Lausanne University Hospital and University of Lausanne, Switzerland
| | - Marie-Catherine Vozenin
- Department of Radiation Oncology, Lausanne University Hospital and University of Lausanne, Switzerland; Radiation Oncology Laboratory, Department of Radiation Oncology. Lausanne University Hospital and University of Lausanne, Switzerland
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Bourhis J, Montay-Gruel P, Gonçalves Jorge P, Bailat C, Petit B, Ollivier J, Jeanneret-Sozzi W, Ozsahin M, Bochud F, Moeckli R, Germond JF, Vozenin MC. Clinical translation of FLASH radiotherapy: Why and how? Radiother Oncol 2019; 139:11-17. [PMID: 31253466 DOI: 10.1016/j.radonc.2019.04.008] [Citation(s) in RCA: 230] [Impact Index Per Article: 46.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Revised: 03/21/2019] [Accepted: 04/03/2019] [Indexed: 11/19/2022]
Abstract
Over the past decades, technological advances have transformed radiation therapy (RT) into a precise and powerful treatment for cancer patients. Nevertheless, the treatment of radiation-resistant tumors is still restricted by the dose-limiting normal tissue complications. In this context, FLASH-RT is emerging in the field. Consisting of delivering doses within an extremely short irradiation time, FLASH-RT has been identified as a promising new tool to enhance the differential effect between tumors and normal tissues. Indeed, preclinical studies on various animal models and a veterinarian clinical trial have recently shown that compared to conventional dose-rate RT, FLASH-RT could control tumors while minimizing normal tissue toxicity. In the present review, we summarize the main data supporting the clinical translation of FLASH-RT and explore its feasibility, the key irradiation parameters and the potential technologies needed for a successful clinical translation.
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Affiliation(s)
- Jean Bourhis
- Department of Radiation Oncology, Department of Oncology, Lausanne University Hospital and Lausanne University, Switzerland; Radiation Oncology Laboratory, Department of Radiation Oncology, Department of Oncology, Lausanne University Hospital and Lausanne University, Switzerland.
| | - Pierre Montay-Gruel
- Department of Radiation Oncology, Department of Oncology, Lausanne University Hospital and Lausanne University, Switzerland; Radiation Oncology Laboratory, Department of Radiation Oncology, Department of Oncology, Lausanne University Hospital and Lausanne University, Switzerland
| | - Patrik Gonçalves Jorge
- Department of Radiation Oncology, Department of Oncology, Lausanne University Hospital and Lausanne University, Switzerland; Radiation Oncology Laboratory, Department of Radiation Oncology, Department of Oncology, Lausanne University Hospital and Lausanne University, Switzerland; Institute of Radiation Physics, Lausanne University Hospital Lausanne University, Switzerland
| | - Claude Bailat
- Institute of Radiation Physics, Lausanne University Hospital Lausanne University, Switzerland
| | - Benoît Petit
- Department of Radiation Oncology, Department of Oncology, Lausanne University Hospital and Lausanne University, Switzerland; Radiation Oncology Laboratory, Department of Radiation Oncology, Department of Oncology, Lausanne University Hospital and Lausanne University, Switzerland
| | - Jonathan Ollivier
- Department of Radiation Oncology, Department of Oncology, Lausanne University Hospital and Lausanne University, Switzerland; Radiation Oncology Laboratory, Department of Radiation Oncology, Department of Oncology, Lausanne University Hospital and Lausanne University, Switzerland
| | - Wendy Jeanneret-Sozzi
- Department of Radiation Oncology, Department of Oncology, Lausanne University Hospital and Lausanne University, Switzerland
| | - Mahmut Ozsahin
- Department of Radiation Oncology, Department of Oncology, Lausanne University Hospital and Lausanne University, Switzerland
| | - François Bochud
- Institute of Radiation Physics, Lausanne University Hospital Lausanne University, Switzerland
| | - Raphaël Moeckli
- Institute of Radiation Physics, Lausanne University Hospital Lausanne University, Switzerland
| | - Jean-François Germond
- Institute of Radiation Physics, Lausanne University Hospital Lausanne University, Switzerland
| | - Marie-Catherine Vozenin
- Department of Radiation Oncology, Department of Oncology, Lausanne University Hospital and Lausanne University, Switzerland
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Montay-Gruel P, Acharya MM, Petersson K, Alikhani L, Yakkala C, Allen BD, Ollivier J, Petit B, Jorge PG, Syage AR, Nguyen TA, Baddour AAD, Lu C, Singh P, Moeckli R, Bochud F, Germond JF, Froidevaux P, Bailat C, Bourhis J, Vozenin MC, Limoli CL. Long-term neurocognitive benefits of FLASH radiotherapy driven by reduced reactive oxygen species. Proc Natl Acad Sci U S A 2019; 116:10943-10951. [PMID: 31097580 PMCID: PMC6561167 DOI: 10.1073/pnas.1901777116] [Citation(s) in RCA: 261] [Impact Index Per Article: 52.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Here, we highlight the potential translational benefits of delivering FLASH radiotherapy using ultra-high dose rates (>100 Gy⋅s-1). Compared with conventional dose-rate (CONV; 0.07-0.1 Gy⋅s-1) modalities, we showed that FLASH did not cause radiation-induced deficits in learning and memory in mice. Moreover, 6 months after exposure, CONV caused permanent alterations in neurocognitive end points, whereas FLASH did not induce behaviors characteristic of anxiety and depression and did not impair extinction memory. Mechanistic investigations showed that increasing the oxygen tension in the brain through carbogen breathing reversed the neuroprotective effects of FLASH, while radiochemical studies confirmed that FLASH produced lower levels of the toxic reactive oxygen species hydrogen peroxide. In addition, FLASH did not induce neuroinflammation, a process described as oxidative stress-dependent, and was also associated with a marked preservation of neuronal morphology and dendritic spine density. The remarkable normal tissue sparing afforded by FLASH may someday provide heretofore unrealized opportunities for dose escalation to the tumor bed, capabilities that promise to hasten the translation of this groundbreaking irradiation modality into clinical practice.
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Affiliation(s)
- Pierre Montay-Gruel
- Laboratory of Radiation Oncology, Lausanne University Hospital, University of Lausanne, Lausanne VD-1011, Switzerland
- Department of Radiation Oncology, Lausanne University Hospital, University of Lausanne, Lausanne VD-1011, Switzerland
| | - Munjal M Acharya
- Department of Radiation Oncology, University of California, Irvine, CA 92697-2695
| | - Kristoffer Petersson
- Laboratory of Radiation Oncology, Lausanne University Hospital, University of Lausanne, Lausanne VD-1011, Switzerland
- Department of Radiation Oncology, Lausanne University Hospital, University of Lausanne, Lausanne VD-1011, Switzerland
- Institute of Radiation Physics, Lausanne University Hospital, University of Lausanne, Lausanne VD-1011, Switzerland
| | - Leila Alikhani
- Department of Radiation Oncology, University of California, Irvine, CA 92697-2695
| | - Chakradhar Yakkala
- Laboratory of Radiation Oncology, Lausanne University Hospital, University of Lausanne, Lausanne VD-1011, Switzerland
- Department of Radiation Oncology, Lausanne University Hospital, University of Lausanne, Lausanne VD-1011, Switzerland
| | - Barrett D Allen
- Department of Radiation Oncology, University of California, Irvine, CA 92697-2695
| | - Jonathan Ollivier
- Laboratory of Radiation Oncology, Lausanne University Hospital, University of Lausanne, Lausanne VD-1011, Switzerland
- Department of Radiation Oncology, Lausanne University Hospital, University of Lausanne, Lausanne VD-1011, Switzerland
| | - Benoit Petit
- Laboratory of Radiation Oncology, Lausanne University Hospital, University of Lausanne, Lausanne VD-1011, Switzerland
- Department of Radiation Oncology, Lausanne University Hospital, University of Lausanne, Lausanne VD-1011, Switzerland
| | - Patrik Gonçalves Jorge
- Laboratory of Radiation Oncology, Lausanne University Hospital, University of Lausanne, Lausanne VD-1011, Switzerland
- Department of Radiation Oncology, Lausanne University Hospital, University of Lausanne, Lausanne VD-1011, Switzerland
- Institute of Radiation Physics, Lausanne University Hospital, University of Lausanne, Lausanne VD-1011, Switzerland
| | - Amber R Syage
- Department of Radiation Oncology, University of California, Irvine, CA 92697-2695
| | - Thuan A Nguyen
- Department of Radiation Oncology, University of California, Irvine, CA 92697-2695
| | - Al Anoud D Baddour
- Department of Radiation Oncology, University of California, Irvine, CA 92697-2695
| | - Celine Lu
- Department of Radiation Oncology, University of California, Irvine, CA 92697-2695
| | - Paramvir Singh
- Department of Radiation Oncology, University of California, Irvine, CA 92697-2695
| | - Raphael Moeckli
- Institute of Radiation Physics, Lausanne University Hospital, University of Lausanne, Lausanne VD-1011, Switzerland
| | - François Bochud
- Institute of Radiation Physics, Lausanne University Hospital, University of Lausanne, Lausanne VD-1011, Switzerland
| | - Jean-François Germond
- Institute of Radiation Physics, Lausanne University Hospital, University of Lausanne, Lausanne VD-1011, Switzerland
| | - Pascal Froidevaux
- Institute of Radiation Physics, Lausanne University Hospital, University of Lausanne, Lausanne VD-1011, Switzerland
| | - Claude Bailat
- Institute of Radiation Physics, Lausanne University Hospital, University of Lausanne, Lausanne VD-1011, Switzerland
| | - Jean Bourhis
- Laboratory of Radiation Oncology, Lausanne University Hospital, University of Lausanne, Lausanne VD-1011, Switzerland
- Department of Radiation Oncology, Lausanne University Hospital, University of Lausanne, Lausanne VD-1011, Switzerland
| | - Marie-Catherine Vozenin
- Laboratory of Radiation Oncology, Lausanne University Hospital, University of Lausanne, Lausanne VD-1011, Switzerland;
- Department of Radiation Oncology, Lausanne University Hospital, University of Lausanne, Lausanne VD-1011, Switzerland
| | - Charles L Limoli
- Department of Radiation Oncology, University of California, Irvine, CA 92697-2695;
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Medici S, Carbonez P, Damet J, Bochud F, Bailat C, Pitzschke A. Detecting intake of radionuclides: In vivo screening measurements with conventional radiation protection instruments. RADIAT MEAS 2019. [DOI: 10.1016/j.radmeas.2019.01.022] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Desorgher L, Bochud F, Flury T, Murith C, Baechler S, Bailat C. Model of ambient dose equivalent for radium contamination: Dependence on the geometry of the source. J Environ Radioact 2018; 192:698-708. [PMID: 29674154 DOI: 10.1016/j.jenvrad.2017.12.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Revised: 10/31/2017] [Accepted: 12/19/2017] [Indexed: 06/08/2023]
Abstract
Industrial activities involving radium sources, such as watchmaking, were still common up until the 1960s. They produced contaminations in building materials and the soil in a large variety of geometries. The potential remediation of such places requires instruments that are properly calibrated as well as adequate procedures. We have developed a model that estimates the rate of ambient dose equivalent H˙∗(10) at 10 cm and 1 m from a source of 226Ra and its progeny in both the soil or the building materials. Our model, described here, uses Monte Carlo (GEANT4) computed yield functions of H˙∗(10) per unit activity induced by point-like sources in different contaminated materials. Fit functions of the yield curve of H˙∗(10) are provided for outdoor contamination. The model can be used for any geometrical activity distribution and we present an example showing the dependency of H˙∗(10) on the diameter and the depth profile of the sources, for both outdoor and indoor contamination.
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Affiliation(s)
- Laurent Desorgher
- Institute of Radiation Physics (IRA), Lausanne University Hospital, Lausanne, Switzerland.
| | - François Bochud
- Institute of Radiation Physics (IRA), Lausanne University Hospital, Lausanne, Switzerland
| | - Thomas Flury
- Swiss Federal Office of Public Health, Switzerland
| | | | | | - Claude Bailat
- Institute of Radiation Physics (IRA), Lausanne University Hospital, Lausanne, Switzerland
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Montay-Gruel P, Bouchet A, Jaccard M, Patin D, Serduc R, Aim W, Petersson K, Petit B, Bailat C, Bourhis J, Bräuer-Krisch E, Vozenin MC. X-rays can trigger the FLASH effect: Ultra-high dose-rate synchrotron light source prevents normal brain injury after whole brain irradiation in mice. Radiother Oncol 2018; 129:582-588. [DOI: 10.1016/j.radonc.2018.08.016] [Citation(s) in RCA: 173] [Impact Index Per Article: 28.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Revised: 08/06/2018] [Accepted: 08/23/2018] [Indexed: 11/16/2022]
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Vozenin MC, De Fornel P, Petersson K, Favaudon V, Jaccard M, Germond JF, Petit B, Burki M, Ferrand G, Patin D, Bouchaab H, Ozsahin M, Bochud F, Bailat C, Devauchelle P, Bourhis J. The Advantage of FLASH Radiotherapy Confirmed in Mini-pig and Cat-cancer Patients. Clin Cancer Res 2018; 25:35-42. [PMID: 29875213 DOI: 10.1158/1078-0432.ccr-17-3375] [Citation(s) in RCA: 344] [Impact Index Per Article: 57.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Revised: 02/28/2018] [Accepted: 05/31/2018] [Indexed: 01/30/2023]
Abstract
PURPOSE Previous studies using FLASH radiotherapy (RT) in mice showed a marked increase of the differential effect between normal tissue and tumors. To stimulate clinical transfer, we evaluated whether this effect could also occur in higher mammals. EXPERIMENTAL DESIGN Pig skin was used to investigate a potential difference in toxicity between irradiation delivered at an ultrahigh dose rate called "FLASH-RT" and irradiation delivered at a conventional dose rate called "Conv-RT." A clinical, phase I, single-dose escalation trial (25-41 Gy) was performed in 6 cat patients with locally advanced T2/T3N0M0 squamous cell carcinoma of the nasal planum to determine the maximal tolerated dose and progression-free survival (PFS) of single-dose FLASH-RT. RESULTS Using, respectively, depilation and fibronecrosis as acute and late endpoints, a protective effect of FLASH-RT was observed (≥20% dose-equivalent difference vs. Conv-RT). Three cats experienced no acute toxicity, whereas 3 exhibited moderate/mild transient mucositis, and all cats had depilation. With a median follow-up of 13.5 months, the PFS at 16 months was 84%. CONCLUSIONS Our results confirmed the potential advantage of FLASH-RT and provide a strong rationale for further evaluating FLASH-RT in human patients.See related commentary by Harrington, p. 3.
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Affiliation(s)
- Marie-Catherine Vozenin
- Radio-Oncology Laboratory, Department of Radiation Oncology, Lausanne University Hospital, Lausanne, Switzerland.
| | | | - Kristoffer Petersson
- Radio-Oncology Laboratory, Department of Radiation Oncology, Lausanne University Hospital, Lausanne, Switzerland.,Institute of Radiation Physics (IRA), Lausanne University Hospital, Lausanne, Switzerland
| | - Vincent Favaudon
- Institut Curie, INSERM U1021/CNRS UMR3347, Université Paris-Sud, Orsay, France
| | - Maud Jaccard
- Radio-Oncology Laboratory, Department of Radiation Oncology, Lausanne University Hospital, Lausanne, Switzerland.,Institute of Radiation Physics (IRA), Lausanne University Hospital, Lausanne, Switzerland
| | - Jean-François Germond
- Institute of Radiation Physics (IRA), Lausanne University Hospital, Lausanne, Switzerland
| | - Benoit Petit
- Radio-Oncology Laboratory, Department of Radiation Oncology, Lausanne University Hospital, Lausanne, Switzerland
| | - Marco Burki
- Service de Chirurgie Expérimentale, Département de chirurgie et anesthésie, Lausanne University Hospital, Lausanne, Switzerland
| | | | - David Patin
- Institute of Radiation Physics (IRA), Lausanne University Hospital, Lausanne, Switzerland
| | - Hanan Bouchaab
- Radio-Oncology Laboratory, Department of Radiation Oncology, Lausanne University Hospital, Lausanne, Switzerland
| | - Mahmut Ozsahin
- Radio-Oncology Laboratory, Department of Radiation Oncology, Lausanne University Hospital, Lausanne, Switzerland.,UNIL, Lausanne, Switzerland
| | - François Bochud
- Institute of Radiation Physics (IRA), Lausanne University Hospital, Lausanne, Switzerland
| | - Claude Bailat
- Institute of Radiation Physics (IRA), Lausanne University Hospital, Lausanne, Switzerland
| | | | - Jean Bourhis
- Radio-Oncology Laboratory, Department of Radiation Oncology, Lausanne University Hospital, Lausanne, Switzerland.,UNIL, Lausanne, Switzerland
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Teresa Durán M, Nedjadi Y, Juget F, Bochud F, Bailat C. Fast digital 4πβ−4πγ coincidence counting with offline analysis at IRA. Appl Radiat Isot 2018; 134:329-336. [DOI: 10.1016/j.apradiso.2017.09.029] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Revised: 09/06/2017] [Accepted: 09/19/2017] [Indexed: 11/26/2022]
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Juget F, Nedjadi Y, Buchillier T, Durán T, Bochud F, Kottler C, Bailat C. A portable precision ionization chamber: The transfer ionization reference chamber. Appl Radiat Isot 2018; 134:95-99. [DOI: 10.1016/j.apradiso.2017.10.022] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Revised: 10/09/2017] [Accepted: 10/10/2017] [Indexed: 11/28/2022]
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Jaccard M, Durán MT, Petersson K, Germond JF, Liger P, Vozenin MC, Bourhis J, Bochud F, Bailat C. High dose-per-pulse electron beam dosimetry: Commissioning of the Oriatron eRT6 prototype linear accelerator for preclinical use. Med Phys 2018; 45:863-874. [DOI: 10.1002/mp.12713] [Citation(s) in RCA: 94] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Revised: 09/13/2017] [Accepted: 11/15/2017] [Indexed: 11/10/2022] Open
Affiliation(s)
- Maud Jaccard
- Institute of Radiation Physics; Lausanne University Hospital; Lausanne Switzerland
| | - Maria Teresa Durán
- Institute of Radiation Physics; Lausanne University Hospital; Lausanne Switzerland
| | - Kristoffer Petersson
- Institute of Radiation Physics; Lausanne University Hospital; Lausanne Switzerland
| | | | | | - Marie-Catherine Vozenin
- Department of Radiation Oncology; Lausanne University Hospital; Lausanne Switzerland
- Radio-Oncology Laboratory; DO/CHUV; Lausanne University Hospital; Lausanne Switzerland
| | - Jean Bourhis
- Department of Radiation Oncology; Lausanne University Hospital; Lausanne Switzerland
- Radio-Oncology Laboratory; DO/CHUV; Lausanne University Hospital; Lausanne Switzerland
| | - François Bochud
- Institute of Radiation Physics; Lausanne University Hospital; Lausanne Switzerland
| | - Claude Bailat
- Institute of Radiation Physics; Lausanne University Hospital; Lausanne Switzerland
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Nedjadi Y, Laedermann JP, Bochud F, Bailat C. On the reverse micelle effect in liquid scintillation counting. Appl Radiat Isot 2017; 125:94-107. [DOI: 10.1016/j.apradiso.2017.04.020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Revised: 03/13/2017] [Accepted: 04/11/2017] [Indexed: 11/25/2022]
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Montay-Gruel P, Petersson K, Jaccard M, Boivin G, Germond JF, Petit B, Doenlen R, Favaudon V, Bochud F, Bailat C, Bourhis J, Vozenin MC. Irradiation in a flash: Unique sparing of memory in mice after whole brain irradiation with dose rates above 100Gy/s. Radiother Oncol 2017; 124:365-369. [PMID: 28545957 DOI: 10.1016/j.radonc.2017.05.003] [Citation(s) in RCA: 340] [Impact Index Per Article: 48.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Revised: 04/13/2017] [Accepted: 05/04/2017] [Indexed: 10/19/2022]
Abstract
This study shows for the first time that normal brain tissue toxicities after WBI can be reduced with increased dose rate. Spatial memory is preserved after WBI with mean dose rates above 100Gy/s, whereas 10Gy WBI at a conventional radiotherapy dose rate (0.1Gy/s) totally impairs spatial memory.
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Affiliation(s)
- Pierre Montay-Gruel
- Department of Radiation Oncology/DO/CHUV, Lausanne University Hospital, Switzerland; Institut Curie, INSERM U1021/CNRS UMR3347, Université Paris-Saclay, Orsay, France
| | | | - Maud Jaccard
- Institute of Radiation Physics (IRA), Lausanne University Hospital, Switzerland
| | - Gaël Boivin
- Department of Radiation Oncology/DO/CHUV, Lausanne University Hospital, Switzerland
| | | | - Benoit Petit
- Department of Radiation Oncology/DO/CHUV, Lausanne University Hospital, Switzerland
| | - Raphaël Doenlen
- Faculty of Life Sciences, Ecole Polytechnique Fédérale de Lausanne, Switzerland
| | - Vincent Favaudon
- Institut Curie, INSERM U1021/CNRS UMR3347, Université Paris-Saclay, Orsay, France
| | - François Bochud
- Institute of Radiation Physics (IRA), Lausanne University Hospital, Switzerland
| | - Claude Bailat
- Institute of Radiation Physics (IRA), Lausanne University Hospital, Switzerland
| | - Jean Bourhis
- Department of Radiation Oncology/DO/CHUV, Lausanne University Hospital, Switzerland
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Petersson K, Montay-Gruel P, Jaccard M, Boivin G, Germond J, Petit B, Bochud F, Bailat C, Bourhis J, Vozenin M. OC-0039: Unique sparing of spatial memory in mice after whole brain irradiation with dose rates above 100Gy/s. Radiother Oncol 2017. [DOI: 10.1016/s0167-8140(17)30483-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Bochud FO, Laedermann JP, Baechler S, Bailat C. CONVERTING SPECIFIC ACTIVITY INTO AMBIENT DOSE EQUIVALENT: UPDATED COEFFICIENTS FOR IN SITU GAMMA SPECTROMETRY. Radiat Prot Dosimetry 2017; 174:167-174. [PMID: 27311733 DOI: 10.1093/rpd/ncw130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2015] [Accepted: 05/06/2016] [Indexed: 06/06/2023]
Abstract
In situ gamma spectrometry is a valuable tool to assess the radionuclides released in the environment and the associated dose. This requires prior establishment of coefficients allowing the conversion of the specific activity into ambient equivalent dose. The aim of this work is to calculate updated conversion factors for monoenergetic photons and for a series of radionuclides of interest. The calculation was performed using the Monte Carlo (MC) method, the GEANT4 MC code, various activity distribution models and up-to-date nuclear decay data. A new set of conversion factors is established in the energy range extending from <100 keV to 8.5 MeV. The coefficients calculated in this work were compared to the data published in the literature.
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Affiliation(s)
- F O Bochud
- Institute of Radiation Physics (IRA), Lausanne University Hospital (CHUV), Switzerland
| | - J-P Laedermann
- Institute of Radiation Physics (IRA), Lausanne University Hospital (CHUV), Switzerland
| | - S Baechler
- Institute of Radiation Physics (IRA), Lausanne University Hospital (CHUV), Switzerland
| | - C Bailat
- Institute of Radiation Physics (IRA), Lausanne University Hospital (CHUV), Switzerland
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Petersson K, Jaccard M, Germond JF, Buchillier T, Bochud F, Bourhis J, Vozenin MC, Bailat C. High dose-per-pulse electron beam dosimetry - A model to correct for the ion recombination in the Advanced Markus ionization chamber. Med Phys 2017; 44:1157-1167. [PMID: 28094853 DOI: 10.1002/mp.12111] [Citation(s) in RCA: 104] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2016] [Revised: 01/11/2017] [Accepted: 01/11/2017] [Indexed: 11/12/2022] Open
Abstract
PURPOSE The purpose of this work was to establish an empirical model of the ion recombination in the Advanced Markus ionization chamber for measurements in high dose rate/dose-per-pulse electron beams. In addition, we compared the observed ion recombination to calculations using the standard Boag two-voltage-analysis method, the more general theoretical Boag models, and the semiempirical general equation presented by Burns and McEwen. METHODS Two independent methods were used to investigate the ion recombination: (a) Varying the grid tension of the linear accelerator (linac) gun (controls the linac output) and measuring the relative effect the grid tension has on the chamber response at different source-to-surface distances (SSD). (b) Performing simultaneous dose measurements and comparing the dose-response, in beams with varying dose rate/dose-per-pulse, with the chamber together with dose rate/dose-per-pulse independent Gafchromic™ EBT3 film. Three individual Advanced Markus chambers were used for the measurements with both methods. All measurements were performed in electron beams with varying mean dose rate, dose rate within pulse, and dose-per-pulse (10-2 ≤ mean dose rate ≤ 103 Gy/s, 102 ≤ mean dose rate within pulse ≤ 107 Gy/s, 10-4 ≤ dose-per-pulse ≤ 101 Gy), which was achieved by independently varying the linac gun grid tension, and the SSD. RESULTS The results demonstrate how the ion collection efficiency of the chamber decreased as the dose-per-pulse increased, and that the ion recombination was dependent on the dose-per-pulse rather than the dose rate, a behavior predicted by Boag theory. The general theoretical Boag models agreed well with the data over the entire investigated dose-per-pulse range, but only for a low polarizing chamber voltage (50 V). However, the two-voltage-analysis method and the Burns & McEwen equation only agreed with the data at low dose-per-pulse values (≤ 10-2 and ≤ 10-1 Gy, respectively). An empirical model of the ion recombination in the chamber was found by fitting a logistic function to the data. CONCLUSIONS The ion collection efficiency of the Advanced Markus ionization chamber decreases for measurements in electron beams with increasingly higher dose-per-pulse. However, this chamber is still functional for dose measurements in beams with dose-per-pulse values up toward and above 10 Gy, if the ion recombination is taken into account. Our results show that existing models give a less-than-accurate description of the observed ion recombination. This motivates the use of the presented empirical model for measurements with the Advanced Markus chamber in high dose-per-pulse electron beams, as it enables accurate absorbed dose measurements (uncertainty estimation: 2.8-4.0%, k = 1). The model depends on the dose-per-pulse in the beam, and it is also influenced by the polarizing chamber voltage, with increasing ion recombination with a lowering of the voltage.
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Affiliation(s)
- Kristoffer Petersson
- CHUV, Institut de Radiophysique, Rue du Grand-Pré 1, CH-1007, Lausanne, Switzerland
| | - Maud Jaccard
- CHUV, Institut de Radiophysique, Rue du Grand-Pré 1, CH-1007, Lausanne, Switzerland
| | | | - Thierry Buchillier
- CHUV, Institut de Radiophysique, Rue du Grand-Pré 1, CH-1007, Lausanne, Switzerland
| | - François Bochud
- CHUV, Institut de Radiophysique, Rue du Grand-Pré 1, CH-1007, Lausanne, Switzerland
| | - Jean Bourhis
- CHUV, Service de Radio-Oncologie, Rue du Bugnon 46, CH - 1011, Lausanne, Switzerland
| | | | - Claude Bailat
- CHUV, Institut de Radiophysique, Rue du Grand-Pré 1, CH-1007, Lausanne, Switzerland
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Jaccard M, Petersson K, Buchillier T, Germond JF, Durán MT, Vozenin MC, Bourhis J, Bochud FO, Bailat C. High dose-per-pulse electron beam dosimetry: Usability and dose-rate independence of EBT3 Gafchromic films. Med Phys 2017; 44:725-735. [PMID: 28019660 DOI: 10.1002/mp.12066] [Citation(s) in RCA: 96] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Revised: 12/02/2016] [Accepted: 12/07/2016] [Indexed: 11/09/2022] Open
Abstract
PURPOSE The aim of this study was to assess the suitability of Gafchromic EBT3 films for reference dose measurements in the beam of a prototype high dose-per-pulse linear accelerator (linac), capable of delivering electron beams with a mean dose-rate (Ḋm ) ranging from 0.07 to 3000 Gy/s and a dose-rate in pulse (Ḋp ) of up to 8 × 106 Gy/s. To do this, we evaluated the overall uncertainties in EBT3 film dosimetry as well as the energy and dose-rate dependence of their response. MATERIAL AND METHODS Our dosimetric system was composed of EBT3 Gafchromic films in combination with a flatbed scanner and was calibrated against an ionization chamber traceable to primary standard. All sources of uncertainties in EBT3 dosimetry were carefully analyzed using irradiations at a clinical radiotherapy linac. Energy dependence was investigated with the same machine by acquiring and comparing calibration curves for three different beam energies (4, 8 and 12 MeV), for doses between 0.25 and 30 Gy. Ḋm dependence was studied at the clinical linac by changing the pulse repetition frequency (f) of the beam in order to vary Ḋm between 0.55 and 4.40 Gy/min, while Ḋp dependence was probed at the prototype machine for Ḋp ranging from 7 × 103 to 8 × 106 Gy/s. Ḋp dependence was first determined by studying the correlation between the dose measured by films and the charge of electrons measured at the exit of the machine by an induction torus. Furthermore, we compared doses from the films to independently calibrated thermo-luminescent dosimeters (TLD) that have been reported as being dose-rate independent up to such high dose-rates. RESULTS We report that uncertainty below 4% (k = 2) can be achieved in the dose range between 3 and 17 Gy. Results also demonstrated that EBT3 films did not display any detectable energy dependence for electron beam energies between 4 and 12 MeV. No Ḋm dependence was found either. In addition, we obtained excellent consistency between films and TLDs over the entire Ḋp range attainable at the prototype linac confirming the absence of any dose-rate dependence within the investigated range (7 × 103 to 8 × 106 Gy/s). This aspect was further corroborated by the linear relationship between the dose-per-pulse (Dp ) measured by films and the charge per pulse (Cp ) measured at the prototype linac exit. CONCLUSION Our study shows that the use of EBT3 Gafchromic films can be extended to reference dosimetry in pulsed electron beams with a very high dose rate. The measurement results are associated with an overall uncertainty below 4% (k = 2) and are dose-rate and energy independent.
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Affiliation(s)
- Maud Jaccard
- Institute of Radiation Physics (IRA), Lausanne University Hospital, Lausanne, Switzerland
| | - Kristoffer Petersson
- Institute of Radiation Physics (IRA), Lausanne University Hospital, Lausanne, Switzerland
| | - Thierry Buchillier
- Institute of Radiation Physics (IRA), Lausanne University Hospital, Lausanne, Switzerland
| | - Jean-François Germond
- Institute of Radiation Physics (IRA), Lausanne University Hospital, Lausanne, Switzerland
| | - Maria Teresa Durán
- Institute of Radiation Physics (IRA), Lausanne University Hospital, Lausanne, Switzerland
| | - Marie-Catherine Vozenin
- Department of Radiation Oncology, Lausanne University Hospital, Lausanne, Switzerland.,Radio-Oncology Laboratory, DO/CHUV, Lausanne University Hospital Lausanne, Lausanne, Switzerland
| | - Jean Bourhis
- Department of Radiation Oncology, Lausanne University Hospital, Lausanne, Switzerland.,Radio-Oncology Laboratory, DO/CHUV, Lausanne University Hospital Lausanne, Lausanne, Switzerland
| | - François O Bochud
- Institute of Radiation Physics (IRA), Lausanne University Hospital, Lausanne, Switzerland
| | - Claude Bailat
- Institute of Radiation Physics (IRA), Lausanne University Hospital, Lausanne, Switzerland
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Pommé S, Stroh H, Paepen J, Van Ammel R, Marouli M, Altzitzoglou T, Hult M, Kossert K, Nähle O, Schrader H, Juget F, Bailat C, Nedjadi Y, Bochud F, Buchillier T, Michotte C, Courte S, van Rooy M, van Staden M, Lubbe J, Simpson B, Fazio A, De Felice P, Jackson T, Van Wyngaardt W, Reinhard M, Golya J, Bourke S, Roy T, Galea R, Keightley J, Ferreira K, Collins S, Ceccatelli A, Unterweger M, Fitzgerald R, Bergeron D, Pibida L, Verheyen L, Bruggeman M, Vodenik B, Korun M, Chisté V, Amiot MN. Evidence against solar influence on nuclear decay constants. Phys Lett B 2016; 761:281-286. [PMID: 28057978 PMCID: PMC5207040 DOI: 10.1016/j.physletb.2016.08.038] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The hypothesis that proximity to the Sun causes variation of decay constants at permille level has been tested and disproved. Repeated activity measurements of mono-radionuclide sources were performed over periods from 200 days up to four decades at 14 laboratories across the globe. Residuals from the exponential nuclear decay curves were inspected for annual oscillations. Systematic deviations from a purely exponential decay curve differ from one data set to another and are attributable to instabilities in the instrumentation and measurement conditions. The most stable activity measurements of alpha, beta-minus, electron capture, and beta-plus decaying sources set an upper limit of 0.0006% to 0.008% to the amplitude of annual oscillations in the decay rate. Oscillations in phase with Earth's orbital distance to the Sun could not be observed within a 10-6 to 10-5 range of precision. There are also no apparent modulations over periods of weeks or months. Consequently, there is no indication of a natural impediment against sub-permille accuracy in half-life determinations, renormalisation of activity to a distant reference date, application of nuclear dating for archaeology, geo- and cosmochronology, nor in establishing the SI unit becquerel and seeking international equivalence of activity standards.
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Affiliation(s)
- S. Pommé
- European Commission, Joint Research Centre (JRC), Retieseweg 111, B-2440Geel, Belgium
| | - H. Stroh
- European Commission, Joint Research Centre (JRC), Retieseweg 111, B-2440Geel, Belgium
| | - J. Paepen
- European Commission, Joint Research Centre (JRC), Retieseweg 111, B-2440Geel, Belgium
| | - R. Van Ammel
- European Commission, Joint Research Centre (JRC), Retieseweg 111, B-2440Geel, Belgium
| | - M. Marouli
- European Commission, Joint Research Centre (JRC), Retieseweg 111, B-2440Geel, Belgium
| | - T. Altzitzoglou
- European Commission, Joint Research Centre (JRC), Retieseweg 111, B-2440Geel, Belgium
| | - M. Hult
- European Commission, Joint Research Centre (JRC), Retieseweg 111, B-2440Geel, Belgium
| | - K. Kossert
- Physikalisch-Technische Bundesanstalt (PTB), Bundesallee 100, 38116 Braunschweig, Germany
| | - O. Nähle
- Physikalisch-Technische Bundesanstalt (PTB), Bundesallee 100, 38116 Braunschweig, Germany
| | - H. Schrader
- Physikalisch-Technische Bundesanstalt (PTB), Bundesallee 100, 38116 Braunschweig, Germany
| | - F. Juget
- Institut de Radiophysique, Lausanne (IRA), Switzerland
| | - C. Bailat
- Institut de Radiophysique, Lausanne (IRA), Switzerland
| | - Y. Nedjadi
- Institut de Radiophysique, Lausanne (IRA), Switzerland
| | - F. Bochud
- Institut de Radiophysique, Lausanne (IRA), Switzerland
| | - T. Buchillier
- Institut de Radiophysique, Lausanne (IRA), Switzerland
| | - C. Michotte
- Bureau International des Poids et Mesures (BIPM), Pavillon de Breteuil, 92310 Sèvres, France
| | - S. Courte
- Bureau International des Poids et Mesures (BIPM), Pavillon de Breteuil, 92310 Sèvres, France
| | - M.W. van Rooy
- Radioactivity Standards Laboratory (NMISA), 15 Lower Hope Road, Rosebank 7700, Cape Town, South Africa
| | - M.J. van Staden
- Radioactivity Standards Laboratory (NMISA), 15 Lower Hope Road, Rosebank 7700, Cape Town, South Africa
| | - J. Lubbe
- Radioactivity Standards Laboratory (NMISA), 15 Lower Hope Road, Rosebank 7700, Cape Town, South Africa
| | - B.R.S. Simpson
- Radioactivity Standards Laboratory (NMISA), 15 Lower Hope Road, Rosebank 7700, Cape Town, South Africa
| | - A. Fazio
- National Institute of Ionizing Radiation Metrology (ENEA), Casaccia Research Centre, Via Anguillarese, 301—S.M. Galeria I-00060 Roma, C.P. 2400, I-00100 Roma A.D., Italy
| | - P. De Felice
- National Institute of Ionizing Radiation Metrology (ENEA), Casaccia Research Centre, Via Anguillarese, 301—S.M. Galeria I-00060 Roma, C.P. 2400, I-00100 Roma A.D., Italy
| | - T.W. Jackson
- Australian Nuclear Science and Technology Organisation (ANSTO), Locked Bag 2001, Kirrawee, NSW 2232, Australia
| | - W.M. Van Wyngaardt
- Australian Nuclear Science and Technology Organisation (ANSTO), Locked Bag 2001, Kirrawee, NSW 2232, Australia
| | - M.I. Reinhard
- Australian Nuclear Science and Technology Organisation (ANSTO), Locked Bag 2001, Kirrawee, NSW 2232, Australia
| | - J. Golya
- Australian Nuclear Science and Technology Organisation (ANSTO), Locked Bag 2001, Kirrawee, NSW 2232, Australia
| | - S. Bourke
- Australian Nuclear Science and Technology Organisation (ANSTO), Locked Bag 2001, Kirrawee, NSW 2232, Australia
| | - T. Roy
- National Research Council of Canada (NRC), 1200 Montreal Road, Ottawa, ON, K1A0R6, Canada
| | - R. Galea
- National Research Council of Canada (NRC), 1200 Montreal Road, Ottawa, ON, K1A0R6, Canada
| | - J.D. Keightley
- National Physical Laboratory (NPL), Hampton Road, Teddington, Middlesex TW11 OLW, UK
| | - K.M. Ferreira
- National Physical Laboratory (NPL), Hampton Road, Teddington, Middlesex TW11 OLW, UK
| | - S.M. Collins
- National Physical Laboratory (NPL), Hampton Road, Teddington, Middlesex TW11 OLW, UK
| | - A. Ceccatelli
- Terrestrial Environment Laboratory, IAEA Environment Laboratories, Department of Nuclear Sciences and Applications, International Atomic Energy Agency (IAEA), Vienna International Centre, PO Box 100, 1400 Vienna, Austria
| | - M. Unterweger
- Physical Measurement Laboratory, National Institute of Standards and Technology (NIST), 100 Bureau Dr., Gaithersburg, MD 20899-8462, USA
| | - R. Fitzgerald
- Physical Measurement Laboratory, National Institute of Standards and Technology (NIST), 100 Bureau Dr., Gaithersburg, MD 20899-8462, USA
| | - D.E. Bergeron
- Physical Measurement Laboratory, National Institute of Standards and Technology (NIST), 100 Bureau Dr., Gaithersburg, MD 20899-8462, USA
| | - L. Pibida
- Physical Measurement Laboratory, National Institute of Standards and Technology (NIST), 100 Bureau Dr., Gaithersburg, MD 20899-8462, USA
| | - L. Verheyen
- Belgian Nuclear Research Centre (SCK·CEN), Boeretang 200, B-2400 Mol, Belgium
| | - M. Bruggeman
- Belgian Nuclear Research Centre (SCK·CEN), Boeretang 200, B-2400 Mol, Belgium
| | - B. Vodenik
- Jožef Stefan Institute (JSI), Jamova 39, 1000 Ljubljana, Slovenia
| | - M. Korun
- Jožef Stefan Institute (JSI), Jamova 39, 1000 Ljubljana, Slovenia
| | - V. Chisté
- CEA, LIST, Laboratoire National Henri Becquerel (LNHB), Bât. 602 PC 111, CEA-Saclay 91191 Gif-sur-Yvette cedex, France
| | - M.-N. Amiot
- CEA, LIST, Laboratoire National Henri Becquerel (LNHB), Bât. 602 PC 111, CEA-Saclay 91191 Gif-sur-Yvette cedex, France
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Cusnir R, Jaccard M, Bailat C, Christl M, Steinmann P, Haldimann M, Bochud F, Froidevaux P. Probing the Kinetic Parameters of Plutonium-Naturally Occurring Organic Matter Interactions in Freshwaters Using the Diffusive Gradients in Thin Films Technique. Environ Sci Technol 2016; 50:5103-10. [PMID: 27064997 DOI: 10.1021/acs.est.5b05435] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
The interaction of trace metals with naturally occurring organic matter (NOM) is a key process of the speciation of trace elements in aquatic environments. The rate of dissociation of metal-NOM complexes will impact the amount of free metal available for biouptake. Assessing the bioavailability of plutonium (Pu) helps to predict its toxic effects on aquatic biota. However, the rate of dissociation of Pu-NOM complexes in natural freshwaters is currently unknown. Here, we used the technique of diffusive gradients in thin films (DGT) with several diffusive layer thicknesses to provide new insights into the dissociation kinetics of Pu-NOM complexes. Results show that Pu complexes with NOM (mainly fulvic acid) are somewhat labile (0.2 ≤ ξ ≤ 0.4), with kd = 7.5 × 10(-3) s(-1). DGT measurements of environmental Pu in organic-rich natural water confirm these findings. In addition, we determined the effective diffusion coefficients of Pu(V) in polyacrylamide (PAM) gel in the presence of humic acid using a diffusion cell (D = 1.70 ± 0.25 × 10(-6) cm(2) s(-1)). These results show that Pu(V) is a more mobile species than Pu(IV).
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Affiliation(s)
- Ruslan Cusnir
- Institute of Radiation Physics, Lausanne University Hospital , 1007 Lausanne, Switzerland
| | - Maud Jaccard
- Institute of Radiation Physics, Lausanne University Hospital , 1007 Lausanne, Switzerland
| | - Claude Bailat
- Institute of Radiation Physics, Lausanne University Hospital , 1007 Lausanne, Switzerland
| | - Marcus Christl
- Laboratory of Ion Beam Physics, ETH Zurich , 8093 Zürich, Switzerland
| | - Philipp Steinmann
- Division of Radiation Protection, Federal Office of Public Health , 3003 Berne, Switzerland
| | - Max Haldimann
- Division of Radiation Protection, Federal Office of Public Health , 3003 Berne, Switzerland
| | - François Bochud
- Institute of Radiation Physics, Lausanne University Hospital , 1007 Lausanne, Switzerland
| | - Pascal Froidevaux
- Institute of Radiation Physics, Lausanne University Hospital , 1007 Lausanne, Switzerland
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69
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Jaccard M, Petersson K, Buchillier T, Bailat C, Germond J, Moeckli R, Bourhis J, Vozenin M, Bochud F. EP-1494: Absolute dosimetry with EBT3 Gafchromic films in a pulsed electron beam at high dose-rate. Radiother Oncol 2016. [DOI: 10.1016/s0167-8140(16)32744-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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70
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Froidevaux P, Bochud F, Baechler S, Castella V, Augsburger M, Bailat C, Michaud K, Straub M, Pecchia M, Jenk TM, Uldin T, Mangin P. 210Po poisoning as possible cause of death: forensic investigations and toxicological analysis of the remains of Yasser Arafat. Forensic Sci Int 2016; 259:1-9. [DOI: 10.1016/j.forsciint.2015.09.019] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2015] [Revised: 09/25/2015] [Accepted: 09/30/2015] [Indexed: 11/25/2022]
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71
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Petersson K, Jaccard M, Vozenin M, Montay-Gruel P, Trompier F, Buchillier T, Germond J, Bochud F, Bourhis J, Bailat C. Dosimetry of ultra high dose rate irradiation for studies on the biological effect induced in normal brain and GBM. Radiother Oncol 2016. [DOI: 10.1016/s0167-8140(16)30172-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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72
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Kropat G, Baechler S, Bailat C, Barazza F, Bochud F, Damet J, Meyer N, Palacios Gruson M, Butterweck G. Calibration of the Politrack® system based on CR39 solid-state nuclear track detectors for passive indoor radon concentration measurements. Radiat Prot Dosimetry 2015; 167:302-305. [PMID: 25948829 DOI: 10.1093/rpd/ncv267] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Swiss national requirements for measuring radon gas exposures demand a lower detection limit of 50 kBq h m(-3), representing the Swiss concentration average of 70 Bq m(-3) over a 1-month period. A solid-state nuclear track detector (SSNTD) system (Politrack, Mi.am s.r.l., Italy) has been acquired to fulfil these requirements. This work was aimed at the calibration of the Politrack system with traceability to international standards and the development of a procedure to check the stability of the system. A total of 275 SSNTDs was exposed to 11 different radon exposures in the radon chamber of the Secondary Calibration Laboratory at the Paul Scherrer Institute, Switzerland. The exposures ranged from 50 to 15000 kBq h m(-3). For each exposure of 20 detectors, 5 SSNTDs were used to monitor possible background exposures during transport and storage. The response curve and the calibration factor of the whole system were determined using a Monte Carlo fitting procedure. A device to produce CR39 samples with a reference number of tracks using a (241)Am source was developed for checking the long-term stability of the Politrack system. The characteristic limits for the detection of a possible system drift were determined following ISO Standard 11929.
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Affiliation(s)
- G Kropat
- Institute of Radiation Physics, Lausanne, Switzerland
| | - S Baechler
- Swiss Federal Office of Public Health, Berne, Switzerland
| | - C Bailat
- Institute of Radiation Physics, Lausanne, Switzerland
| | - F Barazza
- Swiss Federal Office of Public Health, Berne, Switzerland
| | - F Bochud
- Institute of Radiation Physics, Lausanne, Switzerland
| | - J Damet
- Institute of Radiation Physics, Lausanne, Switzerland
| | - N Meyer
- Institute of Radiation Physics, Lausanne, Switzerland
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Bailat C, Bochud F, Juget F, Buchillier T. Development, design and validation of solid reference samples. Appl Radiat Isot 2014; 87:480-4. [PMID: 24378364 DOI: 10.1016/j.apradiso.2013.11.085] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2013] [Accepted: 11/17/2013] [Indexed: 11/25/2022]
Abstract
We developed a method of sample preparation using epoxy compound, which was validated in two steps. First, we studied the homogeneity within samples by scanning tubes filled with radioactive epoxy. We found within-sample homogeneity better than 2%. Then, we studied the homogeneity between samples during a 4.5 h dispensing time. The homogeneity between samples was found to be better than 2%. This study demonstrates that we have a validated method, which assures the traceability of epoxy samples.
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Affiliation(s)
- Claude Bailat
- Institute of Radiation Physics, Lausanne, Switzerland.
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Nedjadi Y, Bailat C, Caffari Y, Froidevaux P, Wastiel C, Kivel N, Guenther-Leopold I, Triscone G, Jaquenod F, Bochud F. A new measurement of the half-life of 166mHo. Appl Radiat Isot 2012; 70:1990-6. [PMID: 22421399 DOI: 10.1016/j.apradiso.2012.02.063] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2011] [Accepted: 02/19/2012] [Indexed: 11/18/2022]
Affiliation(s)
- Y Nedjadi
- Institute of Radiation Physics, University Hospital and University of Lausanne, Switzerland.
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Mayer S, Boschung M, Hoedlmoser H, Buchillier T, Bailat C, Bitterli B. Intercomparison of the response of different photon and neutron detectors around a spent fuel cask. RADIAT MEAS 2012. [DOI: 10.1016/j.radmeas.2012.06.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Bailat C, Buchillier T, Baechler S, Bochud F. Calibration of surface contamination monitors for the detection of iodine incorporation in the thyroid gland. Radiat Prot Dosimetry 2011; 144:505-509. [PMID: 21149292 DOI: 10.1093/rpd/ncq419] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
In Switzerland, individuals exposed to the risk of activity intake are required to perform regular monitoring. Monitoring consists in a screening measurement and is meant to be performed using commonly available laboratory instruments. More particularly, iodine intake is measured using a surface contamination monitor. The goal of the present paper is to report the calibration method developed for thyroid screening instruments. It consists of measuring the instrument response to a known activity located in the thyroid gland of a standard neck phantom. One issue of this procedure remains that the iodine radioisotopes have a short half-life. Therefore, the adequacy and limitations to simulate the short-lived radionuclides with so-called mock radionuclides of longer half-life were also evaluated. In light of the results, it has been decided to use only the appropriate iodine sources to perform the calibration.
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Affiliation(s)
- C Bailat
- Institute of Radiation Physics, Lausanne, Switzerland.
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Abstract
Monte Carlo simulations were carried out to study the response of a thyroid monitor for measuring intake activities of (125)I and (131)I. The aim of the study was 3-fold: to cross-validate the Monte Carlo simulation programs, to study the response of the detector using different phantoms and to study the effects of anatomical variations. Simulations were performed using the Swiss reference phantom and several voxelised phantoms. Determining the position of the thyroid is crucial for an accurate determination of radiological risks. The detector response using the Swiss reference phantom was in fairly good agreement with the response obtained using adult voxelised phantoms for (131)I, but should be revised for a better calibration for (125)I and for any measurements taken on paediatric patients.
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Affiliation(s)
- J Damet
- University Institute for Radiation Physics, University Hospital of Lausanne, 1007 Lausanne, Switzerland.
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Baluc N, Bailat C, Dai Y, Luppo M, Schaublin R, Victoria M. A Comparison of the microstructure and tensile behaviour of irradiated fcc and bcc metals. ACTA ACUST UNITED AC 2011. [DOI: 10.1557/proc-540-539] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
AbstractAs part of an on-going research program, findings are presented from a comparison of the microstructures and associated tensile properties of fcc and bcc materials after high energy proton irradiation, to fluences between 10−4 and 1 dpa, at 300-320 K. Results for this comparison between Cu, Pd, 304 and 316 stainless steel on one side and Fe and the F82H ferritic-martensitic low activation steel on the other are discussed, showing a strong difference in defect accumulation behaviour between the differing crystal structures. The overall deformation behaviour is similar, with an initial localised deformation taking place in all cases, even though the actual deformation mode itself might be different. Furthermore, a comparison is made with some of the materials that have also been irradiated with fission neutrons, showing no influence of the PKA spectra for these irradiation conditions.
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Chauvenet B, Bé MM, Amiot MN, Bobin C, Lépy MC, Branger T, Lanièce I, Luca A, Sahagia M, Wätjen A, Kossert K, Ott O, Nähle O, Dryák P, Sochorovà J, Kovar P, Auerbach P, Altzitzoglou T, Pommé S, Sibbens G, Van Ammel R, Paepen J, Iwahara A, Delgado J, Poledna R, da Silva C, Johansson L, Stroak A, Bailat C, Nedjadi Y, Spring P. International exercise on 124Sb activity measurements. Appl Radiat Isot 2010; 68:1207-10. [DOI: 10.1016/j.apradiso.2010.01.037] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Bailat C, Buchillier T, Caffari Y, Nedjadi Y, Spring P, Estier S, Bochud F. Seven years of gamma-ray spectrometry interlaboratory comparisons in Switzerland. Appl Radiat Isot 2010; 68:1256-60; discussion 1260. [DOI: 10.1016/j.apradiso.2010.01.013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Nedjadi Y, Bailat C, Caffari Y, Bochud F. Standardisation of 18F by a coincidence method using full solid angle detectors. Appl Radiat Isot 2010; 68:1309-13; discussion 1313. [PMID: 20106673 DOI: 10.1016/j.apradiso.2010.01.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A solution of (18)F was standardised with a 4pibeta-4pigamma coincidence counting system in which the beta detector is a one-inch diameter cylindrical UPS89 plastic scintillator, positioned at the bottom of a well-type 5''x5'' NaI(Tl) gamma-ray detector. Almost full detection efficiency-which was varied downwards electronically-was achieved in the beta-channel. Aliquots of this (18)F solution were also measured using 4pigamma NaI(Tl) integral counting and Monte Carlo calculated efficiencies as well as the CIEMAT-NIST method. Secondary measurements of the same solution were also performed with an IG11 ionisation chamber whose equivalent activity is traceable to the Système International de Référence through the contribution IRA-METAS made to it in 2001; IRA's degree of equivalence was found to be close to the key comparison reference value (KCRV). The (18)F activity predicted by this coincidence system agrees closely with the ionisation chamber measurement and is compatible within one standard deviation of the other primary measurements. This work demonstrates that our new coincidence system can standardise short-lived radionuclides used in nuclear medicine.
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Affiliation(s)
- Youcef Nedjadi
- Institut de Radiophysique Appliquée, Lausanne, Switzerland.
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Caffari Y, Spring P, Bailat C, Nedjadi Y, Bochud F. Activity measurements of 18F and 90Y with commercial radionuclide calibrators for nuclear medicine in Switzerland. Appl Radiat Isot 2009; 68:1388-91. [PMID: 19954992 DOI: 10.1016/j.apradiso.2009.11.015] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The activity of radiopharmaceuticals in nuclear medicine is measured before patient injection with radionuclide calibrators. In Switzerland, the general requirements for quality controls are defined in a federal ordinance and a directive of the Federal Office of Metrology (METAS) which require each instrument to be verified. A set of three gamma sources (Co-57, Cs-137 and Co-60) is used to verify the response of radionuclide calibrators in the gamma energy range of their use. A beta source, a mixture of (90)Sr and (90)Y in secular equilibrium, is used as well. Manufacturers are responsible for the calibration factors. The main goal of the study was to monitor the validity of the calibration factors by using two sources: a (90)Sr/(90)Y source and a (18)F source. The three types of commercial radionuclide calibrators tested do not have a calibration factor for the mixture but only for (90)Y. Activity measurements of a (90)Sr/(90)Y source with the (90)Y calibration factor are performed in order to correct for the extra-contribution of (90)Sr. The value of the correction factor was found to be 1.113 whereas Monte Carlo simulations of the radionuclide calibrators estimate the correction factor to be 1.117. Measurements with (18)F sources in a specific geometry are also performed. Since this radionuclide is widely used in Swiss hospitals equipped with PET and PET-CT, the metrology of the (18)F is very important. The (18)F response normalized to the (137)Cs response shows that the difference with a reference value does not exceed 3% for the three types of radionuclide calibrators.
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Affiliation(s)
- Yvan Caffari
- Institut de Radiophysique Appliquée, Lausanne, Switzerland.
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83
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Pachoud M, Bailat C, Buchillier T, Bochud F, Moeckli R. TH-D-352-07: Absolute Dose Determination of Helical Tomotherapy: Comparison Between Several Methods. Med Phys 2008. [DOI: 10.1118/1.2962950] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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84
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Abstract
As part of a project to use the long-lived (T(1/2)=1200a) (166m)Ho as reference source in its reference ionisation chamber, IRA standardised a commercially acquired solution of this nuclide using the 4pibeta-gamma coincidence and 4pigamma (NaI) methods. The (166m)Ho solution supplied by Isotope Product Laboratories was measured to have about 5% Europium impurities (3% (154)Eu, 0.94% (152)Eu and 0.9% (155)Eu). Holmium had therefore to be separated from europium, and this was carried out by means of ion-exchange chromatography. The holmium fractions were collected without europium contamination: 162h long HPGe gamma measurements indicated no europium impurity (detection limits of 0.01% for (152)Eu and (154)Eu, and 0.03% for (155)Eu). The primary measurement of the purified (166m)Ho solution with the 4pi (PC) beta-gamma coincidence technique was carried out at three gamma energy settings: a window around the 184.4keV peak and gamma thresholds at 121.8 and 637.3keV. The results show very good self-consistency, and the activity concentration of the solution was evaluated to be 45.640+/-0.098kBq/g (0.21% with k=1). The activity concentration of this solution was also measured by integral counting with a well-type 5''x5'' NaI(Tl) detector and efficiencies computed by Monte Carlo simulations using the GEANT code. These measurements were mutually consistent, while the resulting weighted average of the 4pi NaI(Tl) method was found to agree within 0.15% with the result of the 4pibeta-gamma coincidence technique. An ampoule of this solution and the measured value of the concentration were submitted to the BIPM as a contribution to the Système International de Référence.
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Affiliation(s)
- Youcef Nedjadi
- Institut Universitaire de Radiophysique Appliquée, Grand Pré 1, 1007 Lausanne, Switzerland
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Nedjadi Y, Spring P, Bailat C, Decombaz M, Triscone G, Gostely JJ, Laedermann JP, Bochud FO. Primary activity measurements with 4πγ NaI(Tl) counting and Monte Carlo calculated efficiencies. Appl Radiat Isot 2007; 65:534-8. [PMID: 17257850 DOI: 10.1016/j.apradiso.2006.10.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2006] [Revised: 10/19/2006] [Accepted: 10/20/2006] [Indexed: 10/23/2022]
Abstract
The radioactive concentrations of (18)F, (88)Y and (152)Eu solutions and the activity of (222)Rn gas ampoules are measured using a primary method involving 4pigamma NaI(Tl) integral counting with a well-type NaI(Tl) detector and efficiencies computed by Monte Carlo simulations. The simulations use the GEANT code coupled with a routine (sch2for), which generates randomly the decay paths and emissions depending on the decay scheme parameters. The resulting radioactive concentrations of (88)Y, (152)Eu and (18)F are found to agree with those measured with other primary measurement methods, such as 4pi (beta, e, X)-gamma coincidence counting or liquid scintillation counting. Results of the determination of the activity of (222)Rn gas ampoules by this method also match the results of an absolute standardisation technique in which radon is condensed onto a cold surface and its alpha-emissions are detected through an accurately specified solid angle.
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Affiliation(s)
- Youcef Nedjadi
- Institut de Radiophysique Appliquée, Grand Pré 1, 1007 Lausanne, Switzerland.
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