RENEB accident simulation exercise

Purpose: The RENEB accident exercise was carried out in order to train the RENEB participants in coordinating and managing potentially large data sets that would be generated in case of a major radiological event. Materials and methods: Each participant was offered the possibility to activate the network by sending an alerting email about a simulated radiation emergency. The same participant had to collect, compile and report capacity, triage categorization and exposure scenario results obtained from all other participants. The exercise was performed over 27 weeks and involved the network consisting of 28 institutes: 21 RENEB members, four candidates and three non-RENEB partners. Results: The duration of a single exercise never exceeded 10 days, while the response from the assisting laboratories never came later than within half a day. During each week of the exercise, around 4500 samples were reported by all service laboratories (SL) to be examined and 54 scenarios were coherently estimated by all laboratories (the standard deviation from the mean of all SL answers for a given scenario category and a set of data was not larger than 3 patient codes). Conclusions: Each participant received training in both the role of a reference laboratory (activating the network) and of a service laboratory (responding to an activation request). The procedures in the case of radiological event were successfully established and tested

Integration of new biological and physical retrospective dosimetry methods into EU emergency response plans : joint RENEB and EURADOS inter-laboratory comparisons

Purpose: RENEB, 'Realising the European Network of Biodosimetry and Physical Retrospective Dosimetry,' is a network for research and emergency response mutual assistance in biodosimetry within the EU. Within this extremely active network, a number of new dosimetry methods have recently been proposed or developed. There is a requirement to test and/or validate these candidate techniques and inter-comparison exercises are a well-established method for such validation. Materials and methods: The authors present details of inter-comparisons of four such new methods: dicentric chromosome analysis including telomere and centromere staining; the gene expression assay carried out in whole blood; Raman spectroscopy on blood lymphocytes, and detection of radiation induced thermoluminescent signals in glass screens taken from mobile phones. Results: In general the results show good agreement between the laboratories and methods within the expected levels of uncertainty, and thus demonstrate that there is a lot of potential for each of the candidate techniques. Conclusions: Further work is required before the new methods can be included within the suite of reliable dosimetry methods for use by RENEB partners and others in routine and emergency response scenarios

TL investigation of glasses from mobile phone screen protectors for radiation accident dosimetry

International audienceTL dosimetric characteristics of glass screen protectors were analyzed for radiation accident dosimetry. Radiation-induced TL signal and intrinsic background signal of these glasses were investigated. An attempt to categorize the glasses according to the shape of their radiation-induced TL glow curve was made. Then, the main dosimetric properties were studied for a category of glass. Radiation-induced TL signal was light sensitive and TL measurements were done on the hard-to-bleach component of the TL signal after bleaching with blue LEDs. The sensitization was negligible after 5 cycles of irradiation and measurement. The dose response was linear up to 20 Gy. Fading was negligible up to 100 h and limited to ~20% for the investigated time range of 12 days. The results of a dose recovery test were promising. These preliminary results are interesting, but further studies on a larger set of screen protectors are needed to really appreciate the potential of glass extracted from mobile phone screen protectors to be used as fortuitous retrospective dosimeter in the event of a radiological accident

Surgivisio® and O-arm®O2 cone beam CT mobile systems for guidance of lumbar spine surgery: Comparison of patient radiation dose

International audiencePurpose : To compare patient radiation doses in cone beam computed tomography (CBCT) of two mobile systems used for navigation-assisted mini-invasive orthopedic surgery: O-arm®O2 and Surgivisio®.Methods : The study focused on imaging of the spine. Thermoluminescent dosimeters were used to measure organs and effective doses (ED) during CBCT. An ionizationchamber and a solid-state sensor were used to measure the incident air-kerma (Ki) atthe center of the CBCT field-of-view and Ki during 2D-imaging, respectively. The PCXMC software was used to calculate patient ED in 2D and CBCT configurations.The image quality in CBCT was evaluated with the CATPHAN phantom. Results : The experimental ED estimate for the low-dose 3D-modes was 2.41 and 0.35 mSv with O-arm®O2 (Low Dose 3D-small-abdomen) and Surgivisio® (3DSU-91images), respectively. PCXMC results were consistent: 1.54 and 0.30 mSv. Organ doses were 5 to 12 times lower with Surgivisio®. Ki at patient skin were comparable on lateral 2D-imaging (0.5 mGy), but lower with O-arm®O2 on anteroposterior (0.3 versus 0.9 mGy). Both systems show poor low contrast resolution and similar high contrast spatial resolution (7 line-pairs/cm).Conclusions : This study is the first to evaluate patient ED and organ doses with Surgivisio®. A significant difference in organs doses was observed between the CBCTsystems. The study demonstrates that Surgivisio® used on spine delivers approximately five to six times less patient ED, compared to O-arm®O2, in low dose 3D-modes. Doses in 2D-mode preceding CBCT were higher with Surgivisio®, but negligible compared to CBCT doses under the experimental conditions tested

Salivary Dysfunctions and Conséquences After RadioiodineTreatment for Thyroid Cancer: Protocol for a Self-Controlled Study(START Study)

International audienceBackground: Following radioiodine (131I) therapy of differentiated thyroid cancer, salivary glands may become inflamed, leading to dysfunctions, then leading to decreases in patients’ nutrition and quality of life. The incidence of these dysfunctions after 131I-therapy is poorly known, and no clinical or genetic factors have been identified to date to define patients at risk, allowing the delivered activity to be adapted to the expected risk of salivary dysfunctions.Objective: this study aims to estimate the incidence of salivary dysfunctions after 131I-therapy, to characterize patients at risk of developing post-treatment dysfunctions using clinical, biomolecular and biochemical factors, and to validate a dosimetric method to calculate the dose received at the salivary gland level in order to analyze the dose response relationship between absorbed doses to salivary glands and salivary dysfunctions.Methods: This prospective cohort aims to include patients for whom a 131I-therapy is indicated within the treatment of their differentiated thyroid cancer in a Paris hospital (40 and 80 patients in a 1.1 GBq and a 3.7 GBq groups respectively). The follow-up is based on 3 scheduled visits: at inclusion (T0, immediately before 131I-therapy), 6 months (T6) and 18 months (T18) after treatment. For each visit, questionnaires on salivary dysfunctions (validated French tool), quality of life (HAD-scale, MOS-SF-36), and nutritional status are administered by a trained clinical research associate. At T0 and at T6, saliva samples and individual measurement of the salivary flow, without and with salivary glands stimulation, are performed. External thermoluminescent dosimeters are positioned on the skin opposite the salivary glands and at the sternal fork immediately before radioiodine administration and removed 5 days after treatment. From dosimeters, an estimation of the dose received at the salivary glands will be performed using physical and computational phantoms.Genetic and epigenetic analyses will be performed in order to look for potential biomarkers of predisposition to develop salivary dysfunctions after 131I-therapy.Results: 139 patients (71% women, mean age=47.4 (±14.3) years old) were included between September 2020 and April 2021 (45 and 94 patients in 1.1GBq and 3.7GBq groups respectively). The 6-months follow-up is still ongoing, and the 18-months follow-up will start in February 2022. Statistical analyses will study the links between salivary dysfunctions and absorbed doses to the salivary glands, taking into account associated factors. In addition, impacts on the patients' quality of life will be analyzed.Conclusions: To our knowledge, this study is the first to investigate the risk of salivary dysfunctions (using both objective and subjective indicators) in relation to organ (salivary glands) doses, based on individual dosimeter records and dose reconstructions. The results will allow the identification of patients at risk of salivary dysfunctions, and thus to propose to clinicians a more adapted follow-up and/or countermeasures to adverse effects

SEED: AN OPERATIONAL NUMERICAL TOOL FOR DOSIMETRIC RECONSTRUCTION IN CASE OF RADIOLOGICAL OVEREXPOSURE

International audienceIn the event of a radiological accident involving one or more victims and potential high doses, it is essential to know the dose distribution within the body, in order to sort the victims according to the severity of the irradiation, and then to take them to the most suitable medical structures. However, there are currently very a few techniques that can be rapidly deployed on field and capable of characterizing an irradiation.Therefore, a numerical simulation tool has been designed. Called SEED, this tool is integrated into a militarized and hardened device, which can dispense with any communication with a cluster of processors thanks to a powerful multi-core calculator. The user can navigate in three dimensions in the accident scene thanks to a graphical user interface including a “first person” camera. It allows a rapid modeling of this scene, and a visual exchange with the victims and witnesses of the event.In order to ensure the performance of the SEED tool, two dosimetric validations were performed. The first consisted in comparing the dose value provided by SEED to that given by a reference calculation code: MCNPX. The purpose of the second validation was to perform an experiment irradiating a physical dummy equipped with dosemeters and to reconstruct this irradiation using SEED. These two validation protocols have shown very satisfactory results. They confirm that this new tool is able to provide useful information to medical teams in charge of dosimetric triage in case of a major external exposure event

Dysfunction of the salivary and lacrimal glands after radioiodine treatment: Preliminary results of a self-controlled study in france

International audienceFollowing radioiodine (131I) therapy of differentiated thyroid cancer, salivary and lacrimal glands may become inflamed, leading to dysfunctions. The incidence of these dysfunctions after 131I-therapy is poorly known, and no clinical or genetic factors have been identified to date to define patients at risk. The aims of this study are 1) to characterize the dysfunction of salivary and lacrimal glands after 131I-therapy, 2) to identify risk factors of salivary and lacrimal dysfunction.START (Salivary dysfuncTion After Radioiodine Treatment) is a prospective study including 139 patients, candidates for a 131I-therapy in the context of their differentiated thyroid cancer (45 and 94 patients in 1.1GBq and 3.7GBq groups respectively). The follow-up was based on 2 scheduled visits: immediately before 131I-therapy (T0) and 6-months after (T6). At each visit, questionnaires on salivary disorders (validated French tool) and dry eye (OSDI© Questionnaire) were administered, and individual salivary flow measurements (without and with salivary gland stimulation) were performed. Descriptive analyses and paired comparisons tests between T0 and T6 were computed.The T6 follow-up started in March 2021, and is still ongoing. Complete information was provided for 122 patients (71% women, mean age=47.4 (±14.3) y). At 6 months after 131I-therapy, stimulated saliva flow rate decreased (from 6.98 (±3.35) to 6.07 (±3.15) mL/min, p<0.01), as well as the difference between stimulated and unstimulated saliva flow rates (from 1.40 (±0.67) to 1.21 (±0.63) mL/min, p<0.01). Also, after 131I-therapy, 19% and 21% of the study population reported dry eye or dry mouth feeling, respectively.This work presents preliminary results of the START study, showing a decrease in salivary and lacrimal gland activity after 131I-therapy. Further analyses will be performed, including saliva biochemical composition, genetic and epigenetic variants, and dose-response relationships (using dosimetric reconstructions)

Dysfunction of the salivary and lacrimal glands after radioiodine treatment: Preliminary results of a self-controlled study in france

International audienceFollowing radioiodine (131I) therapy of differentiated thyroid cancer, salivary and lacrimal glands may become inflamed, leading to dysfunctions. The incidence of these dysfunctions after 131I-therapy is poorly known, and no clinical or genetic factors have been identified to date to define patients at risk. The aims of this study are 1) to characterize the dysfunction of salivary and lacrimal glands after 131I-therapy, 2) to identify risk factors of salivary and lacrimal dysfunction.START (Salivary dysfuncTion After Radioiodine Treatment) is a prospective study including 139 patients, candidates for a 131I-therapy in the context of their differentiated thyroid cancer (45 and 94 patients in 1.1GBq and 3.7GBq groups respectively). The follow-up was based on 2 scheduled visits: immediately before 131I-therapy (T0) and 6-months after (T6). At each visit, questionnaires on salivary disorders (validated French tool) and dry eye (OSDI© Questionnaire) were administered, and individual salivary flow measurements (without and with salivary gland stimulation) were performed. Descriptive analyses and paired comparisons tests between T0 and T6 were computed.The T6 follow-up started in March 2021, and is still ongoing. Complete information was provided for 122 patients (71% women, mean age=47.4 (±14.3) y). At 6 months after 131I-therapy, stimulated saliva flow rate decreased (from 6.98 (±3.35) to 6.07 (±3.15) mL/min, p<0.01), as well as the difference between stimulated and unstimulated saliva flow rates (from 1.40 (±0.67) to 1.21 (±0.63) mL/min, p<0.01). Also, after 131I-therapy, 19% and 21% of the study population reported dry eye or dry mouth feeling, respectively.This work presents preliminary results of the START study, showing a decrease in salivary and lacrimal gland activity after 131I-therapy. Further analyses will be performed, including saliva biochemical composition, genetic and epigenetic variants, and dose-response relationships (using dosimetric reconstructions)

Dysfunction of the salivary and lacrimal glands after radioiodine treatment: Preliminary results of a self-controlled study in france

International audienceFollowing radioiodine (131I) therapy of differentiated thyroid cancer, salivary and lacrimal glands may become inflamed, leading to dysfunctions. The incidence of these dysfunctions after 131I-therapy is poorly known, and no clinical or genetic factors have been identified to date to define patients at risk. The aims of this study are 1) to characterize the dysfunction of salivary and lacrimal glands after 131I-therapy, 2) to identify risk factors of salivary and lacrimal dysfunction.START (Salivary dysfuncTion After Radioiodine Treatment) is a prospective study including 139 patients, candidates for a 131I-therapy in the context of their differentiated thyroid cancer (45 and 94 patients in 1.1GBq and 3.7GBq groups respectively). The follow-up was based on 2 scheduled visits: immediately before 131I-therapy (T0) and 6-months after (T6). At each visit, questionnaires on salivary disorders (validated French tool) and dry eye (OSDI© Questionnaire) were administered, and individual salivary flow measurements (without and with salivary gland stimulation) were performed. Descriptive analyses and paired comparisons tests between T0 and T6 were computed.The T6 follow-up started in March 2021, and is still ongoing. Complete information was provided for 122 patients (71% women, mean age=47.4 (±14.3) y). At 6 months after 131I-therapy, stimulated saliva flow rate decreased (from 6.98 (±3.35) to 6.07 (±3.15) mL/min, p<0.01), as well as the difference between stimulated and unstimulated saliva flow rates (from 1.40 (±0.67) to 1.21 (±0.63) mL/min, p<0.01). Also, after 131I-therapy, 19% and 21% of the study population reported dry eye or dry mouth feeling, respectively.This work presents preliminary results of the START study, showing a decrease in salivary and lacrimal gland activity after 131I-therapy. Further analyses will be performed, including saliva biochemical composition, genetic and epigenetic variants, and dose-response relationships (using dosimetric reconstructions)

START (Salivary dysfuncTions After Radioiodine Treatment) Preliminary results of a self-controlled study in France

International audienceIntroductionThe treatment of differentiated thyroid cancer includes generally a total thyroidectomy, followed by a radioiodine (131I)-therapy. Due to their ability to concentrate iodine, the salivary glands may present inflammation after administration of 131I, which may be symptomatic, may lead to longer-term chronic abnormalities, resulting in alterations in patients’ nutrition and quality of life. The incidence of salivary dysfunctions after 131I-therapy varies considerably between studies due to methodological limitations. Also, the occurrence of these dysfunctions may be linked to increased uptake and/or retention of 131I in the salivary glands and/or individual radiosensitivity. However, no clinical or genetic factors have been identified to date to define patients at risk, allowing the delivered activity to be adapted to the expected risk of salivary dysfunctions. The aims of this study are 1) to estimate the incidence of salivary dysfunctions after 131I-therapy, 2) to investigate the risk of salivary dysfunctions in relation to 131I dosimeter recorded doses.MethodsThis prospective study included 139 patients, candidates for a 131I-therapy in the context of their differentiated thyroid cancer, treated in the Nuclear Medicine department of the Pitié-Salpêtrière hospital (45 and 94 patients in 1.1GBq and a 3.7GBq dose groups respectively) treated between September, 2020 and June, 2021. External thermoluminescent dosimeters were placed opposite the salivary glands and at the sternal fork immediately before radioiodine administration and removed 5 days after. The dose precisely received at the salivary glands was established from dosimeter records, physical and computational phantomsThe follow-up is based on 2 scheduled visits: at inclusion (T0, immediately before 131I-therapy) and 6 months after (T6). For each visit, questionnaires about salivary disorders (validated French tool) is administered, and individual measurements of the salivary flow (without and with salivary glands stimulation) are performed. Poisson regression models with adjustment for potential confounding factors will be used. ResultsThe T6 follow-up started in March, 2021, and is still ongoing. Statistical analyses will be set up in October, 2021, and results will be presented. Both subjective (questionnaire responses) and objective (saliva flow rates) indicators of salivary dysfunctions will be analysed, and a combined indicator will be created.DiscussionIt is the first study to investigate the risk of salivary dysfunctions (using both objective and subjective indicators) in relation to organ (salivary glands) doses, based on individual dosimeter records and dose reconstructions. Potential associated risk factors will be investigated. The results will allow the identification of patients at risk of salivary dysfunctions, and thus to propose to clinicians a more adapted follow-up and/or countermeasures to adverse effects