scholarly journals Prospective lifetime radiation risk of cancer among Russian cleanup workers in Chernobyl

2021 ◽  
Vol 30 (1) ◽  
pp. 94-109
Author(s):  
S.Yu. Chekin ◽  
◽  
A.N. Menyajlo ◽  
V.V. Kashcheev ◽  
S.S. Lovachev ◽  
...  
Keyword(s):  
Chernobyl Accident ◽  
Radiation Safety ◽  
Risk Model ◽  
Radiation Risk ◽  
Epidemiological Data ◽  
Risk Models ◽  
Radiation Risks ◽  
Risk Of Cancer ◽  
Cleanup Workers

As stated in the Basic sanitary rules of radiation safety, radiation risk is one of the main character-istics of radiation safety. Before the work persons involved in cleanup operations after radiation accidents should be informed about subsequent risks to their health. However, mathematical models for radiation risk prediction and methods for its calculation are currently at the stage of scientific research and have not yet been standardized for solving practical problems of risk pre-diction. At the international level, UNSCEAR, ICRP and WHO developed radiation risk models on the basis of radiation-epidemiological data on survivors of Hiroshima and Nagasaki atomic bombings in August 1945. In recent decades, data on radiation-epidemiological follow-up of co-horts contained people exposed to radiation after the Chernobyl accident in 1986, in particular NRER data, have been used to identify and assess radiation risks. The radiation risk models iden-tified from the Chernobyl cohorts of exposed individuals differ from the models identified from the Japanese cohort, which leads, respectively, to different projections of lifetime radiation risk. The purpose of this work is to compare quantitatively the possible lifetime radiation risks of can-cer for a cohort of Russian liquidators of the Chernobyl accident, evaluated with radiation risk models developed by UNSCEAR, WHO and NRER. It is shown that after 2020, 1297 cases of cancer are expected in the cohort of Russian liquidators, this figure is 2.4 times higher than esti-mates obtained with the international models. The radiation risk model of leukemia, built on the basis of NRER follow-up data, predicts 145 cases of leukemia in the observed cohort of liquida-tors, which is 8 times higher than the values estimated with the use of international models. Since the liquidators of the considered cohort are generally over 50 years old, the results obtained may indicate the need to adjust the dose limits established by the current radiation safety standards based on ICRP risk models for people over 50 years old.

Calibration Algorithms for Estimating the Number of Radiogenic Deaths in a Cohort

2021 ◽  
Vol 65 (6) ◽  
pp. 47-56
Author(s):  
E Vasilyev ◽  
E Annenkova ◽  
A. Biryukov ◽  
Yu. Orlov ◽  
S Dumansky ◽  
...  
Keyword(s):  
Chernobyl Accident ◽  
Risk Model ◽  
Radiation Risk ◽  
Total Mortality ◽  
Calculation Algorithm ◽  
Risk Models ◽  
Risk Of Death ◽  
Calculation Algorithms ◽  
Radiation Induced ◽  
Low Sensitivity

Background: Development of algorithms for estimating the number of radiogenic deaths in a cohort that happened or may happen before an arbitrary moment in time. Algorithms should be based on continuous lifelong risk models and minimize the errors of estimates based on deformable non-radiation models ("seed" models) reflecting the general patterns of Russian mortality, but with the possibility of calibrating according to selected data. Materials and methods: For the study, the databases of the register of liquidators of the consequences of the Chernobyl accident – employees of the enterprises of the Ministry of Atomic Energy of Russia were used. Persons with a non-zero dose of ionizing radiation received as a result of the accident and who were registered in the register until 2018 were selected from the register. There are 7324 men and 655 women in this sample. The number of deaths from the beginning of the observation period until 1996, 2006, 2016 from all causes, as well as from solid cancers and leukemias, was used as a reference data for the calibration. Radiation risk was calculated using UNSCEAR 2006 models. Calibration was performed using the Levenberg – Marquardt method. Results: A general formula was obtained for assessing the excess lifetime risk of death, which is the basis of the developed algorithms. The "seed" models of the risk of death from all causes and from solid cancers and leukemia’s were obtained. In accordance with the purpose of the work, two algorithms have been developed. The first algorithm is intended for direct (without using radiation risk models) estimation of the number of radiation-induced deaths in a cohort. The second uses radiation risk models. The performance of the algorithms was tested using the industry register of liquidators of the consequences of the Chernobyl accident. In particular, a 30 % calculated increase in the estimated number of deaths from radiation-induced solid cancers was recorded using calibrated models. Conclusions: The proposed calculation algorithms for calibrated models provide reliable (if the radiation risk models are considered sufficiently adequate) estimates of the number of Chernobyl deaths for points in time preceding the current one and, presumably, more accurate predictive estimates compared to the calculation algorithm for uncalibrated models. The low sensitivity of the lifelong risk model to variations in the parameters of the background models and the total mortality model makes it possible to apply models calibrated according to the liquidator register to other closely related populations (NPP workers, etc.).

scholarly journals LEUKEMIA INCIDENCE AND MORTALITY OF RECOVERY OPERATION WORKERS OF THE CHERNOBYL ACCIDENT: ASSESSMENT OF RADIATION RISKS FOR THE FOLLOW-UP PERIOD OF 1986–2014

2018 ◽  
Vol 11 (4) ◽  
pp. 7-17 ◽  
Author(s):  
V. K. Ivanov ◽  
V. V. Kashcheev ◽  
S. V. Karpenko ◽  
S. E. Glebova ◽  
K. A. Tumanov ◽  
...  
Keyword(s):  
Relative Risk ◽  
Chronic Lymphocytic Leukemia ◽  
Chernobyl Accident ◽  
Radiation Risk ◽  
Lymphocytic Leukemia ◽  
Excess Relative Risk ◽  
Entire Body ◽  
Average Dose ◽  
Incidence And Mortality

Leukemia incidence in the cohort of Russian male recovery operation workers (liquidators) was estimated at 78110 people for the follow-up period 1986-2014. The average age of the liquidators at the time of entry into the zone of works for liquidation of the Chernobyl accident was 34 years. Radiation risk of leukemia incidence (with the exception of chronic lymphocytic leukemia) was analyzed for liquidators who had official data on the individual dose of external gamma radiation of the entire body accumulated over the period of work. During the follow-up period, 157 cases of leukemia were detected (with the exception of chronic lymphocytic leukemia). Collection and verification of data of hemoblastoses cases among persons exposed to radiation exposure was carried out according to a specially developed algorithm. The average dose of the liquidators was 108 mGy. During the period 1986–1997 was established a statistically significant (p<0.05) linear dose dependence of the leukemia incidence with an excess relative risk of ERR/Gy=4.17 (90% CI: 0.18, 13.24). From 1998 until the end of the follow-up period, as well as for the entire follow-up period (from 1986 to 2014), no statistically significant estimates of excess relative risk were found. For mortality, no statistically significant estimates of excess relative risk and relative risk were found for any of the observation periods. The obtained estimates of the radiation risk of morbidity indicate that a statistically significant excess leukemia incidence of liquidators, which may be associated with external gamma irradiation, is manifested in the first decade after exposure.

scholarly journals Potential radiological risk for the population during implementation of the Rosatom Proryv project. Part 2. Radiation detriment assessment

2020 ◽  
Vol 29 (4) ◽  
pp. 48-68
Author(s):  
V.K. Ivanov ◽  
◽  
S.Yu. Chekin ◽  
A.N. Menyajlo ◽  
S.S. Lovachev ◽  
...  
Keyword(s):  
Nuclear Power ◽  
Radiation Safety ◽  
Fuel Cycle ◽  
Radiation Risk ◽  
Population Based ◽  
Normal Operation ◽  
Radiation Doses ◽  
Radiation Risks ◽  
Proryv Project ◽  
Current Health Care System

Nuclear power is effective and safe source of electricity. Meanwhile, uranium reserves in the earth's crust will run out in 100 years with the development of traditional nuclear reactors. The Rosatom “Proryv” project implementation will allow multiplying fuel sources for the new genera-tion nuclear power through the closing fuel cycle. Radiation safety of the new nuclear powers should be based on the state of the art Russian national and international regulations, as well as on predicted radiation doses, estimates of potential radiation risks and radiation detriment of the public. Developed methods for computational analysis of possible doses of estimates of radia-tion risks and population-based detriment, associated with atmospheric fallouts of radioactive substances from the BREST-OD-300 reactor, corresponds to the currently recognized approach-es to evaluating safety of nuclear energy facilities. Developed method for radiation detriment es-timating is in accordance with ICRP recommendations. It allows making assessment of radiation-associated health effects for Russian population with account of patients’ quality of life provided by the current health care system. The analysis of possible radiation doses and potential radia-tion risks shows that the upper 95% confidence bound of radiation detriment for the critical group of population in the town of Seversk (girls of 5 years of age) even in the event of beyond design basis accident at the reactor equals 1.1610-5 year-1, and does not exceed the radiation risk limit of 510-5 years-1, established by Russian national radiation safety regulations NRB-99/2009 for the population during normal operation of ionizing radiation sources. In the event of an accidental situation on the Brest-OD-300 reactor, the average estimates of radiation risks for the population living within the 30-km zone around the JSC “Siberian Chemical Combine” will generally remain in the range of negligible risk and will not exceed the level of 10-6 year-1.

scholarly journals Development of the automated system for assessing radiation risks to the population of the Russian Federation based on the data of radiation-hygienic certification of territories

2021 ◽  
Vol 14 (4) ◽  
pp. 114-121
Author(s):  
R. R. Akhmatdinov ◽  
A. M. Biblin ◽  
L. V. Repin
Keyword(s):  
Russian Federation ◽  
Radiation Safety ◽  
Negative Impact ◽  
Radiation Risk ◽  
Quantitative Characteristic ◽  
Computer Programs ◽  
Automated System ◽  
Risk Indicators ◽  
Radiation Risks ◽  
The Russian Federation

The assessment of the radiation risk based on the data of the radiation-hygienic passports of the territories makes it possible to give a brief quantitative characteristic of the negative impact of sources of ionizing radiation on the health of the population of various regions of the Russian Federation at the population level. The calculation of individual indicators of radiation risk for the population of particular region of the Russian Federation is a time-consuming task that requires referring to radiation-hygienic passports of territories for particular years. Therefore, the purpose of the performed work was to develop specialized software designed to assess the indicators of radiation risk to the population of the Russian Federation according to the data of the radiation-hygienic certification system of territories. Automation of the calculation of radiation risk allows not only to simplify the calculation procedure but also to carry out a spatial-temporal analysis of risk in dynamics for different regions of the Russian Federation over long periods. The methodological basis for the software development is guideline MR 2.6.1.0145-19 “Calculation of radiation risk according to the data contained in the radiation-hygienic passports of the territories to provide a comprehensive comparative assessment of the radiation safety status of the population of the subjects of the Russian Federation”. To achieve the set goal, two computer programs were developed: 1) to automate the process of calculating radiation risk based on the information contained in the radiation-hygienic passports of territories, a computer program “Calculation of radiation risk indicators according to RGPT data”; 2) for the spatial visualization of the calculations, a specialized geographic information system “Radiation risks of the population of the Russian Federation according to radiation-hygienic certification data”. The computer programs developed in the course of the work allow an automated calculation of radiation risk based on the data of radiation-hygienic passports of territories, visualize the spatially distributed results of calculating radiation risk, carry out a preliminary assessment of the state of radiation safety, based on the data contained in radiation-hygienic passports of territories using radiation risk indicators. 

scholarly journals Association between Radiotherapy and Risk of Cancer Associated Venous Thromboembolism: A Sub-Analysis of the COMPASS—CAT Study

Cancers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 1033
Author(s):  
Sally Temraz ◽  
Nour Moukalled ◽  
Grigorios T. Gerotziafas ◽  
Ismail Elalamy ◽  
Luis Jara-Palomares ◽  
...  
Keyword(s):  
Missing Data ◽  
Risk Model ◽  
Locally Advanced ◽  
Cellular Toxicity ◽  
Patients With Cancer ◽  
Increased Risk ◽  
Post Hoc ◽  
Risk Of Cancer ◽  
Anthracycline Chemotherapy

Background: The role and effect of radiotherapy in the development of VTE has not been extensively explored; Methods: This is a post-hoc analysis from the COMPASS-CAT trial. Patients with breast, lung, colon or ovarian cancer, with early, locally advanced or metastatic disease and receiving chemotherapy were included. Primary endpoint was documented symptomatic VTE; Results: A total of 1355 patients were enrolled between November 2013 and November 2015. Of those, 194 patients were excluded because of missing data or the use of anticoagulation. Of the evaluable patients, 361 patients received radiotherapy (33.6%) At a median follow up of 6 months, 9.1% (n = 33) of patients receiving radiotherapy developed a VTE event (excluding those with missing data on follow up). After applying the competing risk model, radiotherapy remained significantly associated with increased risk for VTE (HR 2.47, 95% CI: 1.47–4.12, p = 0.001). Stratification analysis for the cohort that received radiotherapy revealed an increased risk of VTE in women compared to men (10.8% vs. 2.7%; p = 0.03), in those older than 50 (12.2% vs. 3.7%; p = 0.011); for patients receiving anthracycline chemotherapy (14.4% vs. 2.9%; p < 0.001) and hormonal therapy (12.9% vs. 3.9%; p < 0.001); Conclusions: Analysis from the COMPASS-CAT revealed a significant correlation between radiotherapy and VTE in patients with cancer. Further studies are needed to better understand the potential cellular toxicity associated with radiotherapy.

scholarly journals Estimating of radiation risks of malignant neoplasms among Russian Chernobyl cleanup workers

2021 ◽  
Vol 30 (1) ◽  
pp. 58-77
Author(s):  
V.V. Kashcheev ◽  
◽  
S.Yu. Chekin ◽  
S.V. Karpenko ◽  
M.A. Maksioutov ◽  
...  
Keyword(s):  
Relative Risk ◽  
Cancer Incidence ◽  
Radiation Risk ◽  
Excess Relative Risk ◽  
Solid Cancer ◽  
Radiation Doses ◽  
Risk Coefficient ◽  
Incidence And Mortality ◽  
Cleanup Workers

The paper considers radiation risks of solid cancer incidence and mortality, as well as risk of leu-kemia incidence (other than chronic lymphocytic leukemia) among Russian Chernobyl cleanup workers (liquidators). The study of the cohort of liquidators carried out at the National Radiation Epidemiological Registry (NRER) was based on the follow-up data collected from 1992 over 2019. The size of the Chernobyl cleanup workers cohort exceeded 65 thousand people, their av-erage age at the time of entering the exclusion zone was 34 years, the average external gamma radiation dose received by liquidators during their cleanup work was about 0.133 Gy. Radiation-induced risks of solid cancer incidence and mortality in the study cohort were statistically signifi-cant, the risk magnitude rose with increasing the follow-up length. For the maximum follow-up period, from 1992 over 2019, the excess relative risk coefficient for solid cancer incidence was ERR/Gy=0.62, 95% CI (0.29; 0.98), and excess relative risk coefficient for solid cancer mortality was ERR/Gy=0.74, 95% CI (0.32; 1.22), the estimated coefficients were in good agreement with similar coefficients calcu-lated for the Russian liquidators with the use of ICRP radiation risk models. Non-parametric esti-mates of relative radiation risk within the same dose intervals for solid cancers and for leukemias in the cohort of liquidators were statistically significant for radiation doses above 0.150 Gy. For radiation doses below 0,150 Гр the linear non-threshold model is conservative, i.e. there was ev-idence for statistically significant radiation risk of leukemia incidence among liquidators during the first 11 years after the accident, from 1986 over 1997, ERR/Gy=4.41, 95% CI (0.24; 14.23). In later years, until 2018 there was no evidence of radiation-related risk of leukemia incidence. Out-comes of future studies will impact on optimization of radiological protection, development of reference levels for Russian general public exposure and improvement of the system for delivery of targeted medical care to people exposed to radiation.

scholarly journals Ural cohort of the population exposed in childhood

2020 ◽  
Vol 13 (1) ◽  
pp. 91-93
Author(s):  
S. A. Shalaginov ◽  
L. Yu. Krestinina
Keyword(s):  
Radiation Risk ◽  
High Sensitivity ◽  
Southern Urals ◽  
Morbidity And Mortality ◽  
Childhood And Adolescence ◽  
The Southern Urals ◽  
Definition Of ◽  
Age Range ◽  
Risk Of Cancer

The object of the study is the cohort of individuals exposed in the Southern Urals in the 1950s at the age of 0–19 years. The relevance of the creation of the cohort of individuals exposed in childhood and adolescence is determined by their high sensitivity to radiation exposure and is associated with the need for differentiated assessments of the radiation risk of morbidity and mortality for individuals exposed at different stages of ontogenesis. The work includes definition of the cohort, the criteria for inclusion and exclusion from the cohort. According to the data as of 01.01.2019, the created cohort includes 32,461 potential members exposed as a result of living in the riverside villages of the Techa River and on the territory of the East Ural radioactive trace; the follow-up period of the cohort is 70 years (from 1950 to 2019). The cohort has an almost equal number of men and women, includes two ethnic groups (Slavs and Turks), the age range is from 0 to 91 years. The formed cohort can be used to assess the radiogenic risk of cancer and non-cancer morbidity and mortality for the low and medium doses of exposure

scholarly journals A Validation Study Comparing Risk Prediction Models of IgA Nephropathy

2021 ◽  
Vol 12 ◽  
Author(s):  
Yan Ouyang ◽  
Zhanzheng Zhao ◽  
Guisen Li ◽  
Huimin Luo ◽  
Feifei Xu ◽  
...  
Keyword(s):  
Prediction Models ◽  
Risk Model ◽  
Collaborative Study ◽  
Low Risk ◽  
Composite Outcome ◽  
Risk Models ◽  
Clinical Indicators ◽  
Clinical Model ◽  
Risk Patients

We aimed to validate three IgAN risk models proposed by an international collaborative study and another CKD risk model generated by an extended CKD cohort with our multicenter Chinese IgAN cohort. Biopsy-proven IgAN patients with an eGFR ≥15 ml/min/1.73 m2 at baseline and a minimum follow-up of 6 months were enrolled. The primary outcomes were a composite outcome (50% decline in eGFR or ESRD) and ESRD. The performance of those models was assessed using discrimination, calibration, and reclassification. A total of 2,300 eligible cases were enrolled. Of them, 288 (12.5%) patients reached composite outcome and 214 (9.3%) patients reached ESRD during a median follow-up period of 30 months. Using the composite outcome for analysis, the Clinical, Limited, Full, and CKD models had relatively good performance with similar C statistics (0.81, 0.81, 0.82, and 0.82, respectively). While using ESRD as the end point, the four prediction models had better performance (all C statistics &gt; 0.9). Furthermore, subgroup analysis showed that the models containing clinical and pathological variables (Full model and Limited model) had better discriminatory abilities than the models including only clinical indicators (Clinical model and CKD model) in low-risk patients characterized by higher baseline eGFR (≥60 ml/min/1.73 m2). In conclusion, we validated recently reported IgAN and CKD risk models in our Chinese IgAN cohort. Compared to pure clinical models, adding pathological variables will increase performance in predicting ESRD in low-risk IgAN patients with baseline eGFR ≥60 ml/min/1.73 m2.

scholarly journals Integrated prognostication of intrahepatic cholangiocarcinoma by contrast-enhanced computed tomography: the adjunct yield of radiomics

2021 ◽  
Author(s):  
Mario Silva ◽  
Michele Maddalo ◽  
Eleonora Leoni ◽  
Sara Giuliotti ◽  
Gianluca Milanese ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Risk Model ◽  
Full Range ◽  
Univariate Analysis ◽  
Distant Metastases ◽  
Risk Models ◽  
Contrast Enhanced ◽  
Venous Phase ◽  
Enhanced Computed Tomography

Abstract Purpose To test radiomics for prognostication of intrahepatic mass-forming cholangiocarcinoma (IMCC) and to develop a comprehensive risk model. Methods Histologically proven IMCC (representing the full range of stages) were retrospectively analyzed by volume segmentation on baseline hepatic venous phase computed tomography (CT), by two readers with different experience (R1 and R2). Morphological CT features included: tumor size, hepatic satellite lesions, lymph node and distant metastases. Radiomic features (RF) were compared across CT protocols and readers. Univariate analysis against overall survival (OS) warranted ranking and selection of RF into radiomic signature (RSign), which was dichotomized into high and low-risk strata (RSign*). Models without and with RSign* (Model 1 and 2, respectively) were compared. Results Among 78 patients (median follow-up 262 days, IQR 73–957), 62/78 (79%) died during the study period, 46/78 (59%) died within 1 year. Up to 10% RF showed variability across CT protocols; 37/108 (34%) RF showed variability due to manual segmentation. RSign stratified OS (univariate: HR 1.37 for R1, HR 1.28 for R2), RSign* was different between readers (R1 0.39; R2 0.57). Model 1 showed AUC 0.71, which increased in Model 2: AUC 0.81 (p < 0.001) and AIC 89 for R1, AUC 0.81 (p = 0.001) and AIC 90.2 for R2. Conclusion The use of RF into a unified RSign score stratified OS in patients with IMCC. Dichotomized RSign* classified survival strata, its inclusion in risk models showed adjunct yield. The cut-off value of RSign* was different between readers, suggesting that the use of reference values is hampered by interobserver variability.

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