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BSE 27 février 2015 - no. 200

Documentation en Radioprotection d'EDF - DPI - Division Production Nucléaire

 


27 février 2015 - no. 200

 

Projets de publication

Article

SPYCHER BD, LUPATSCH JE, ZWAHLEN M et al. - Background ionizing radiation and the risk of childhood cancer : a census-based nationwide cohort study. – Environmental health perspectives, online 23 février 2015, 29 p.

 

Vient de paraître

Articles

MOLLER AP, MOUSSEAU TA – Strong effects of ionizing radiation from Chernobyl on mutation rates. - Scientific reports, 10/02/2015, 5:8363, 6 p.

 

XU P, LUO H, HUANG GL et al. - Exposure to ionizing radiation during dental x-rays is not associated with risk of developing meningioma : a meta-analysis based on seven case-control studies. – PlosOne, 06/02/2015, 10, 2, 12 p.

 

SMITH JN, BROWN RM, WILLIAMS WJ et al. - Arrival of the Fukushima radioactivity plume in North American continental waters. – Proceedings of the National Academy of Sciences, 03/02/2015, 112, 5, 1310-1315.

 

BERRINGTON DE GONZALEZ A, WONG J, KLEINERMAN R et al. – Risk of second cancers according to radiation therapy technique and modality in prostate cancer survivors. - International journal of radiation oncology biology physics, 01/02/2015, 91, 2, 295-302.

  • abstract

PURPOSE: Radiation therapy (RT) techniques for prostate cancer are evolving rapidly, but the impact of these changes on risk of second cancers, which are an uncommon but serious consequence of RT, are uncertain. We conducted a comprehensive assessment of risks of second cancer according to RT technique (>10 MV vs ≤10 MV and 3-dimensional [3D] vs 2D RT) and modality (external beam RT, brachytherapy, and combined modes) in a large cohort of prostate cancer patients.

METHODS AND MATERIALS: The cohort was constructed using the Surveillance Epidemiology and End Results-Medicare database. We included cases of prostate cancer diagnosed in patients 66 to 84 years of age from 1992 to 2004 and followed through 2009. We used Poisson regression analysis to compare rates of second cancer across RT groups with adjustment for age, follow-up, chemotherapy, hormone therapy, and comorbidities. Analyses of second solid cancers were based on the number of 5-year survivors (n=38,733), and analyses of leukemia were based on number of 2-year survivors (n=52,515) to account for the minimum latency period for radiation-related cancer.

RESULTS: During an average of 4.4 years' follow-up among 5-year prostate cancer survivors (2DRT = 5.5 years; 3DRT = 3.9 years; and brachytherapy = 2.7 years), 2933 second solid cancers were diagnosed. There were no significant differences in second solid cancer rates overall between 3DRT and 2DRT patients (relative risk [RR] = 1.00, 95% confidence interval [CI]: 0.91-1.09), but second rectal cancer rates were significantly lower after 3DRT (RR = 0.59, 95% CI: 0.40-0.88). Rates of second solid cancers for higher- and lower-energy RT were similar overall (RR = 0.97, 95% CI: 0.89-1.06), as were rates for site-specific cancers. There were significant reductions in colon cancer and leukemia rates in the first decade after brachytherapy compared to those after external beam RT.

CONCLUSIONS: Advanced treatment planning may have reduced rectal cancer risks in prostate cancer survivors by approximately 3 cases per 1000 after 15 years. Despite concerns about the neutron doses, we did not find evidence that higher energy therapy was associated with increased second cancer risks.

 

ZABLOTSKA LB, NADYROV EA, ROZHKO AV et al. - Analysis of thyroid malignant pathologic findings identified during 3 rounds of screening (1997-2008) of a cohort of children and adolescents from Belarus exposed to radioiodines after the Chernobyl accident. - Cancer, 01/02/2015, 121, 3, 457-466.

  • abstract

BACKGROUND: Recent studies of children and adolescents who were exposed to radioactive iodine-131 (I-131) after the 1986 Chernobyl nuclear accident in Ukraine exhibited a significant dose-related increase in the risk of thyroid cancer, but the association of radiation doses with tumor histologic and morphologic features is not clear.

METHODS: A cohort of 11,664 individuals in Belarus who were aged ≤18 years at the time of the accident underwent 3 cycles of thyroid screening during 1997 to 2008. I-131 thyroid doses were estimated from individual thyroid activity measurements taken within 2 months after the accident and from dosimetric questionnaire data. Demographic, clinical, and tumor pathologic characteristics of the patients with thyroid cancer were analyzed using 1-way analysis of variance, chi-square tests or Fisher exact tests, and logistic regression.

RESULTS: In total, 158 thyroid cancers were identified as a result of screening. The majority of patients had T1a and T1b tumors (93.7%), with many positive regional lymph nodes (N1; 60.6%) but few distant metastases (M1; <1%). Higher I-131 doses were associated with higher frequency of solid and diffuse sclerosing variants of thyroid cancer (P < .01) and histologic features of cancer aggressiveness, such as lymphatic vessel invasion, intrathyroidal infiltration, and multifocality (all P < .03). Latency was not correlated with radiation dose. Fifty-two patients with self-reported thyroid cancers which were diagnosed before 1997 were younger at the time of the accident and had a higher percentage of solid variant cancers compared with patients who had screening-detected thyroid cancers (all P < .0001).

CONCLUSIONS: I-131 thyroid radiation doses were associated with a significantly greater frequency of solid and diffuse sclerosing variants of thyroid cancer and various features of tumor aggressiveness.

 

ALIYU AS, RAMLI AT – The world's high background natural radiation areas (HBNRAs) revisited : a broad overview of the dosimetric, epidemiological and radiobiological issues. - Radiation measurements, 02/2015, 73, 51-59.

  • abstract

The residents of the world's high background natural radiation areas (HBNRAs), such as Ramsar (in Iran), Guarapari (in Brazil), Orissa and Kerala (in India) and Yangjiang (in China) have lived in these areas for generations under extraordinary radiation fields. The failure of earlier epidemiological studies to report any substantial increase in cancer incidence in HBNRAs has raised some controversy regarding the validity of the linear no-threshold hypothesis. This paper reviews some of the most recent studies of HBNRAs with the intent of stimulating greater research interest in the dosimetric, epidemiological and radiobiological issues related to the world's HBNRAs and proposes solutions to the challenges facing HBNRA studies. This paper may serve as a useful reference for some of the harder-to-find literature.

 

BOLLAERTS K, SONCK M. SIMONS K et al. - Thyroid cancer incidence around the Belgian nuclear sites : surrogate exposure modelling. - Cancer epidemiology, 02/2015, 39, 1, 48-54.

 

BOUVILLE A, TOOHEY RE, BOICE JD et al. – Dose reconstruction for the million worker study : status and guidelines. - Health physics, 02/2015, 108, 2, 206-220.

  • abstract

The primary aim of the epidemiologic study of one million U.S. radiation workers and veterans [the Million Worker Study (MWS)] is to provide scientifically valid information on the level of radiation risk when exposures are received gradually over time and not within seconds, as was the case for Japanese atomic bomb survivors. The primary outcome of the epidemiologic study is cancer mortality, but other causes of death such as cardiovascular disease and cerebrovascular disease will be evaluated. The success of the study is tied to the validity of the dose reconstruction approaches to provide realistic estimates of organ-specific radiation absorbed doses that are as accurate and precise as possible and to properly evaluate their accompanying uncertainties. The dosimetry aspects for the MWS are challenging in that they address diverse exposure scenarios for diverse occupational groups being studied over a period of up to 70 y. The dosimetric issues differ among the varied exposed populations that are considered: atomic veterans, U.S. Department of Energy workers exposed to both penetrating radiation and intakes of radionuclides, nuclear power plant workers, medical radiation workers, and industrial radiographers. While a major source of radiation exposure to the study population comes from external gamma- or x-ray sources, for some of the study groups, there is a meaningful component of radionuclide intakes that requires internal radiation dosimetry assessments. Scientific Committee 6-9 has been established by the National Council on Radiation Protection and Measurements (NCRP) to produce a report on the comprehensive organ dose assessment (including uncertainty analysis) for the MWS. The NCRP dosimetry report will cover the specifics of practical dose reconstruction for the ongoing epidemiologic studies with uncertainty analysis discussions and will be a specific application of the guidance provided in NCRP Report Nos. 158, 163, 164, and 171. The main role of the Committee is to provide guidelines to the various groups of dosimetrists involved in the MWS to ensure that certain dosimetry criteria are considered: calculation of annual absorbed doses in the organs of interest, separation of low and high linear-energy transfer components, evaluation of uncertainties, and quality assurance and quality control. It is recognized that the MWS and its approaches to dosimetry are a work in progress and that there will be flexibility and changes in direction as new information is obtained with regard to both dosimetry and the epidemiologic features of the study components. This paper focuses on the description of the various components of the MWS, the available dosimetry results, and the challenges that have been encountered. It is expected that the Committee will complete its report in 2016.

 

BRENT RL - Protection of the gametes embryo/fetus from prenatal radiation exposure. - Health physics, 02/2015, 108, 2, 242-274.

  • abstract

There is no convincing evidence of germline mutation manifest as heritable disease in the offspring of humans attributable to ionizing radiation, yet radiation clearly induces mutations in microbes and somatic cells of rodents and humans. Doses to the embryo estimated to be in the range of 0.15-0.2 Gy during the pre-implantation and pre-somite stages may increase the risk of embryonic loss. However, an increased risk of congenital malformations or growth retardation has not been observed in the surviving embryos. These results are primarily derived from mammalian animal studies and are referred to as the "all-or-none phenomenon." The tissue reaction effects of ionizing radiation (previously referred to as deterministic effects) are congenital malformations, mental retardation, decreased intelligence quotient, microcephaly, neurobehavioral effects, convulsive disorders, growth retardation (height and weight), and embryonic and fetal death (miscarriage, stillbirth). All these effects are consistent with having a threshold dose below which there is no increased risk. The risk of cancer in offspring that have been exposed to diagnostic x-ray procedures while in utero has been debated for 55 y. High doses to the embryo or fetus (e.g., >0.5 Gy) increase the risk of cancer. Most pregnant women exposed to x-ray procedures and other forms of ionizing radiation today received doses to the embryo or fetus <0.1 Gy. The risk of cancer in offspring exposed in utero at exposures <0.1 Gy is controversial and has not been fully resolved. Diagnostic imaging procedures using ionizing radiation that are clinically indicated for the pregnant patient and her fetus should be performed because the clinical benefits outweigh the potential oncogenic risks.

 

EVANGELIOU N, BALKANSKI Y, COZIC A et al. – Fire evolution in the radioactive forests of Ukraine and Belarus : future risks for the population and the environment. - Ecological monographs, 02/2015, 85, 1, 49-72.

  • abstract

In this paper, we analyze the current and future status of forests in Ukraine and Belarus that were contaminated after the nuclear disaster in 1986. Using several models, together with remote-sensing data and observations, we studied how climate change in these forests may affect fire regimes. We investigated the possibility of 137Cs displacement over Europe by studying previous fire events, and examined three fire scenarios that depended on different emission altitudes of 137Cs, assuming that 10% of the forests were affected by fires. Field

measurements and modeling simulations confirmed that numerous radioactive contaminants are still present at these sites in extremely large quantities.

Forests in Eastern Europe are characterized by large, highly fire-prone patches that are conducive to the development of extreme crown fires. Since 1986, there has been a positive correlation between extreme fire events and drought in the two contaminated regions. Litter carbon storage in the area has doubled since 1986 due to increased tree mortality and decreased decomposition rates; dead trees and accumulating litter in turn can provide fuel for wildfires that pose a high risk of redistributing radioactivity in future years. Intense fires in 2002, 2008, and 2010 resulted in the displacement of 137Cs to the south; the cumulative amount of 137Cs re-deposited over Europe was equivalent to 8% of that deposited following the initial Chernobyl disaster. However, a large amount of 137Cs still remains in these forests, which could be remobilized along with a large number of other dangerous, long-lived, refractory radionuclides. We predict that an expanding flammable area associated with climate change will lead to a high risk of radioactive contamination with characteristic fire peaks in the future. Current fire-fighting infrastructure in the region is inadequate due to understaffing and lack of funding. Our data yield the first cogent predictions for future fire incidents and provide scientific insights that could inform and spur evidence-based policy decisions concerning highly contaminated regions around the world, such as those of Chernobyl.

 

GUNDERMAN RB, GONDA AS – Radiums girls. - Radiology, 02/2015, 274, 2, 314-318.

(pas d’abstract disponible)

 

LAND CB, KWON D, HOFFMAN FO et al. – Accounting for shared and unshared dosimetric uncertainties in the dose response for ultrasound-detected thyroid nodules after exposure to radioactive fallout. - Radiation research, 02/2015, 183, 2, 159-173.

  • abstract

Dosimetic uncertainties, particularly those that are shared among subgroups of a study population, can bias, distort or reduce the slope or significance of a dose response. Exposure estimates in studies of health risks from environmental radiation exposures are generally highly uncertain and thus, susceptible to these methodological limitations. An analysis was published in 2008 concerning radiation-related thyroid nodule prevalence in a study population of 2,994 villagers under the age of 21 years old between August 1949 and September 1962 and who lived downwind from the Semipalatinsk Nuclear Test Site in Kazakhstan. This dose-response analysis identified a statistically significant association between thyroid nodule prevalence and reconstructed doses of fallout-related internal and external radiation to the thyroid gland; however, the effects of dosimetric uncertainty were not evaluated since the doses were simple point "best estimates". In this work, we revised the 2008 study by a comprehensive treatment of dosimetric uncertainties. Our present analysis improves upon the previous study, specifically by accounting for shared and unshared uncertainties in dose estimation and risk analysis, and differs from the 2008 analysis in the following ways: 1. The study population size was reduced from 2,994 to 2,376 subjects, removing 618 persons with uncertain residence histories; 2. Simulation of multiple population dose sets (vectors) was performed using a two-dimensional Monte Carlo dose estimation method; and 3. A Bayesian model averaging approach was employed for evaluating the dose response, explicitly accounting for large and complex uncertainty in dose estimation. The results were compared against conventional regression techniques. The Bayesian approach utilizes 5,000 independent realizations of population dose vectors, each of which corresponds to a set of conditional individual median internal and external doses for the 2,376 subjects. These 5,000 population dose vectors reflect uncertainties in dosimetric parameters, partly shared and partly independent, among individual members of the study population. Risk estimates for thyroid nodules from internal irradiation were higher than those published in 2008, which results, to the best of our knowledge, from explicitly accounting for dose uncertainty. In contrast to earlier findings, the use of Bayesian methods led to the conclusion that the biological effectiveness for internal and external dose was similar. Estimates of excess relative risk per unit dose (ERR/Gy) for males (177 thyroid nodule cases) were almost 30 times those for females (571 cases) and were similar to those reported for thyroid cancers related to childhood exposures to external and internal sources in other studies. For confirmed cases of papillary thyroid cancers (3 in males, 18 in females), the ERR/Gy was also comparable to risk estimates from other studies, but not significantly different from zero. These findings represent the first reported dose response for a radiation epidemiologic study considering all known sources of shared and unshared errors in dose estimation and using a Bayesian model averaging (BMA) method for analysis of the dose response.

 

LEE Y, KIM YJ, CHOI YJ et al. – Radiation-induced changes in DNA methylation and their relationship to chromosome aberrations in nuclear power plant workers. - International journal of radiation biology, 02/2015, 91, 2, 142-149.

  • abstract

Purpose : We investigated the association between occupational radiation exposure and DNA methylation changes in nuclear power plant workers. We also evaluated whether radiation- induced DNA methylation alterations are associated with chromosome aberrations.

Materials and methods : The study population included 170 radiation-exposed workers and 30 controls. We measured global, long interspersed nuclear element-1 (LINE-1), and satellite 2 methylation levels in blood leukocyte DNA. The analysis of chromosome aberrations was performed on peripheral lymphocytes.

Results : Global DNA methylation levels were lower in radiation-exposed workers than in controls. The methylation levels were negatively associated with the recent 1.5-year radiation dose in a multiple linear regression model (β = - 0.0088, p ≤ 0.001); the levels increased proportionally with the total cumulative dose in radiation-exposed workers. LINE-1 methylation levels were higher in radiation-exposed workers than in controls and were significantly associated with the total cumulative radiation dose in a multiple linear regression model (β = - 0.031, p = 0.035). Global DNA methylation levels were also correlated with chromosome aberrations among workers. Workers with low global methylation levels had a higher frequency of chromosome aberrations than did subjects with high global methylation levels.

Conclusion : Occupational exposure to low-dose radiation could affect DNA methylation levels, and the radiation-induced DNA methylation alterations may be associated with chromosome aberrations.

 

PATIL R, SZABO E, FELLS JI et al. - Combined mitigation of the gastrointestinal and hematopoietic acute radiation syndromes by an LPA2 receptor-specific nonlipid agonist. – Chemistry and biology, 02/2015, 22, 2, 206-216.

 

RINGEN K, DEMENT J, WELCH L et al. – Mortality of older construction and craft workers employed at department of energy (DOE) nuclear sites : follow-up through 2011. - American journal of industrial medicine, 02/2015, 58, 2, 152-167.

  • abstract

BACKGROUND: The Building Trades National Medical Screening Program (BTMed) was established in 1996 to provide occupational medicine screening examinations for construction workers who have worked at US Department of Energy nuclear sites. Workers participating in BTMed between 1998 and 2011 were followed to determine their vital status and mortality experience through December 31, 2011.

METHODS: The cohort includes 18,803 BTMed participants and 2,801 deaths. Cause-specific Standardized Mortality Ratios (SMRs) were calculated based on US death rates.

RESULTS: Mortality was elevated for all causes, all cancers, cancers of the trachea, bronchus, and lung and lymphatic and hematopoietic system, mesothelioma, COPD, and asbestosis.

CONCLUSIONS: Construction workers employed at DOE sites have a significantly increased risk for occupational illnesses. Risks are associated with employment during all time periods covered including after 1980. The cancer risks closely match the cancers identified for DOE compensation from radiation exposures. Continued medical surveillance is important.

 

SUZUKI K, MITSUTAKE N, SAENKO V et al. – Radiation signatures in childhood thyroid cancers after the Chernobyl accident : possible roles of radiation in carcinogenesis. - Cancer science, 02/2015, 106, 2, 127-133.

 

THOMPSON PA, KWAMENA NO, ILIN M et al. – Levels of tritium in soils and vegetation near Canadian nuclear facilities releasing tritium to the atmosphere : implications for environmental models. - Journal of environmental radioactivity, 02/2015, 140, 105-113.

  • abstract

Concentrations of organically bound tritium (OBT) and tritiated water (HTO) were measured over two growing seasons in vegetation and soil samples obtained in the vicinity of four nuclear facilities and two background locations in Canada. At the background locations, with few exceptions, OBT concentrations were higher than HTO concentrations: OBT/HTO ratios in vegetation varied between 0.3 and 20 and values in soil varied between 2.7 and 15. In the vicinity of the four nuclear facilities OBT/HTO ratios in vegetation and soils deviated from the expected mean value of 0.7, which is used as a default value in environmental transfer models. Ratios of the OBT activity concentration in plants ([OBT]plant) to the OBT activity concentration in soils ([OBT]soil) appear to be a good indicator of the long-term behaviour of tritium in soil and vegetation. In general, OBT activity concentrations in soils were nearly equal to OBT activity concentrations in plants in the vicinity of the two nuclear power plants. [OBT]plant/[OBT]soil ratios considerably below unity observed at one nuclear processing facility represents historically higher levels of tritium in the environment. The results of our study reflect the dynamic nature of HTO retention and OBT formation in vegetation and soil during the growing season. Our data support the mounting evidence suggesting that some parameters used in environmental transfer models approved for regulatory assessments should be revisited to better account for the behavior of HTO and OBT in the environment and to ensure that modelled estimates (e.g., plant OBT) are appropriately conservative.

 

ROSEN EM, DAY R, SINGH VK - New approaches to radiation protection. – Frontiers in oncology, 20/01/2015, 4, 381, 15 p.

 

GOYAL N, CAMACHO F, MANGANO J et al. – Evaluating for a geospatial relationship between radon levels and thyroid cancer in Pennsylvania. - Laryngoscope, 01/2015, 125, 1, E45-49.

 

SHEN BM, JI YQ, TIAN Q et al. - Determination of total tritium in urine from residents living in the vicinity of nuclear power plants in Qinshan, China. – International journal of environmental research and public health, 01/2015, 12, 1, 888-894.

 

SZUMIEL I - Ionizing radiation-induced oxidative stress, epigenetic changes and genomic instability : the pivotal role of mitochondria. - International journal of radiation biology, 01/2015, 91, 1, 1-12.

  • abstract

Purpose: To review the data concerning the role of endogenously generated reactive oxygen species (ROS) in the non-targeted ionizing radiation (IR) effects and in determination of the cell population's fate, both early after exposure and after many generations.

Conclusions: The short-term as well as chronic oxidative stress responses mainly are produced due to ROS generation by the electron transport chain (ETC) of the mitochondria and by the cytoplasmic NADPH oxidases. Whether the induction of the oxidative stress and its consequences occur or are hampered in a single cell largely depends on the interaction between the nucleus and the cellular population of several hundred or thousands of mitochondria that are genetically heterogeneous. High intra-mitochondrial ROS level is damaging the mitochondrial (mt) DNA and its mutations affect the epigenetic control mechanisms of the nuclear (n) DNA, by decreasing the activity of methyltransferases and thus, causing global DNA hypomethylation. These changes are transmitted to the progeny of the irradiated cells. The chronic oxidative stress is the main cause of the late post-radiation effects, including cancer, and this makes it an important adverse effect of exposure to IR and a target for radiological protection.

 

TANG FR, LOKE WK - Molecular mechanisms of low dose ionizing radiation-induced hormesis, adaptive responses, radioresistance, bystander effects, and genomic instability. - International journal of radiation biology, 01/2015, 91, 1, 13-27.

  • abstract

Purposes: To review research progress on the molecular mechanisms of low dose ionizing radiation (LDIR)-induced hormesis, adaptive responses, radioresistance, bystander effects, and genomic instability in order to provide clues for therapeutic approaches to enhance biopositive effects (defined as radiation-induced beneficial effects to the organism), and control bionegative effects (defined as radiation-induced harmful effects to the organism) and related human diseases.

Conclusions: Experimental studies have indicated that Ataxia telangiectasia-mutated (ATM), extracellular signal-related kinase (ERK), mitogen-activated protein kinase (MAPK), phospho-c-Jun NH2-terminal kinase (JNK) and protein 53 (P53)-related signal transduction pathways may be involved in LDIR-induced hormesis; MAPK, P53 may be important for adaptive response; ATM, cyclooxygenase-2 (COX-2), ERK, JNK, reactive oxygen species (ROS), P53 for radioresistance; COX-2, ERK, MAPK, ROS, tumor necrosis factor receptor alpha (TNFα) for LDIR-induced bystander effect; whereas ATM, ERK, MAPK, P53, ROS, TNFα-related signal transduction pathways are involved in LDIR-induced genomic instability. These results suggest that different manifestations of LDIR-induced cellular responses may have different signal transduction pathways. On the other hand, LDIR-induced different responses may also share the same signal transduction pathways. For instance, P53 has been involved in LDIR-induced hormesis, adaptive response, radioresistance and genomic instability. Current data therefore suggest that caution should be taken when designing therapeutic approaches using LDIR to induce beneficial effects in humans.

 

KRASNOV V, KRYUKOV V, SAMEDOVA E et al. - Early aging in Chernobyl clean-up workers : long-term study. – BioMed research international, 2015, 2015 :948473, 5 p.

 

Compte-rendu de congrès

CE – Radiation induced long-term health effects after medical exposure. Radiation protection no. 182. EU Scientific seminar. Luxembourg, 19 novembre 2013. – 2015, 68 p.

 

Norme

AFNOR – Radioprotection - Sources radioactives scellées - Exigences générales et classification. – 14/02/2015, NF EN ISO 2919, 32 p.

  • résumé

Le présent document établit un système de classification des sources radioactives scellées selon leurs performances d'essais, et spécifie des prescriptions générales, des essais de qualification et en cours de production ainsi que des prescriptions relatives au marquage et à la certification. Il décrit une série d'essais permettant au fabricant de sources radioactives scellées d'évaluer la sécurité de son produit dans les conditions d'emploi, et à l'utilisateur de choisir les types de sources adaptés pour l'application voulue, notamment lorsque se pose le problème de la protection contre la dispersion des matières radioactives et donc de l'exposition à un rayonnement ionisant. Le présent document peut aussi servir de guide aux autorités réglementaires.

 

Rapports

AIEA - International peer review mission on mid-and-long-term roadmap towards the decommissioning of TEPCO's Fukushima Daiichi nuclear power station units 1-4 (3rd mission). Preliminary report. – 17/02/2015, 16 p.

 

IRSN - Recommandations sur les bonnes pratiques en matière de radioprotection des travailleurs dans la perspective de l’abaissement de la limite réglementaire de dose équivalente pour le cristallin. – IRSN, PRP-HOM 2013-00010, 27 p.

 

CE – General guidelines on risk management in external beam radiotherapy. Radiation protection no. 181. – 2015, 72 p. + 205 p.(annexes)

 

ICRP – Publication 127 : Radiological protection in ion beam radiotherapy. – Annals of the ICRP, 2014, 43, 4, 1-113 p.

  • abstract

The goal of external-beam radiotherapy is to provide precise dose localisation in the treatment volume of the target with minimal damage to the surrounding normal tissue. Ion beams, such as protons and carbon ions, provide excellent dose distributions due primarily to their finite range, allowing a significant reduction of undesired exposure of normal tissue. Careful treatment planning is required for the given type and localisation of the tumour to be treated in order to maximise treatment efficiency and minimise the dose to normal tissue. Radiation exposure in outof- field volumes arises from secondary neutrons and photons, particle fragments, and photons from activated materials. These unavoidable doses should be considered from the standpoint of radiological protection of the patient. Radiological protection of medical staff at ion beam radiotherapy facilities requires special attention.

Appropriate management and control are required for the therapeutic equipment and the air in the treatment room that can be activated by the particle beam and its secondaries. Radiological protection and safety management should always conform with regulatory requirements. The current regulations for occupational exposures in photon radiotherapy are applicable to ion beam radiotherapy with protons or carbon ions. However, ion beam radiotherapy requires a more complex treatment system than conventional radiotherapy, and appropriate training of staff and suitable quality assurance programmes are recommended to avoid possible accidental exposure of patients, to minimise unnecessary doses to normal tissue, and to minimise radiation exposure of staff.

 

 

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