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Computed tomography has become increasingly common for diagnosing socially significant diseases in recent years. In foreign practice, screening schemes for lung cancer in people belonging to risk categories have been developed and implemented. These schemes have been successfully used over the past 10 years. In this case, “low-dose” scanning protocols are used, which make it possible to perform examination with patient effective dose several times lower compared to standard protocols. Lung cancer screening methods using low-dose computed tomography are beginning to be introduced in the Russian Federation. To ensure the radiation safety of those individuals eligible for inclusion in screening programs or participating in biomedical research testing lung cancer screening, it is necessary to evaluate effective doses from low-dose computed tomography and compare these doses to established radiation dose limits. This study assessed the patients’ effective doses who underwent different types of low-dose computed tomography of chest at two medical organizations. The results of the study show that it is possible to achieve non-exceedance of the current annual effective dose limit of 1 mSv only for patients weighing less than 90 kg. For patients with higher body weight, the minimum effective dose will be in the range of 1.2 – 1.4 mSv. The results of the study indicate the need to make changes to the current regulatory and methodological documents of Rospotrebnadzor to ensure the possibility of using low-dose computed tomography as part of screening for all categories of people.

The practical implementation of radiation protection principles in the medical exposure of patients often tends to fall into one of two extremes: either excessive simplification of the methodology for assessing radiation health detriment, or its excessive complexity. An example of an excessively simplified approach is the assessment of radiation risk to patients using effective dose and radiation damage coefficients (nominal risk coefficients) as presented in Norms of the Radiation Safety NRB-99/2009. An example of an unjustifiably complex approach can be considered Tables 1-2 in MR 2.6.1.0215-20 "Assessment of radiation risk to patients during X-ray diagnostic radiological examinations," which indicate "lifetime risk values of death taking into account harm from reduced quality of life due to cancer of various organs and tissues and genetic effects from medical examinations" for a wide range of medical diagnostic X-ray radiological examinations in five-year age groups of patients. The main shortcomings of the simplified approach can be considered the lack of differences in risk assessment between individuals of different sexes and ages, although the fact of higher radiosensitivity in children compared to adults and in women compared to men can be considered universally recognized. The risk assessment approach proposed in MR 2.6.1.0215-20 addresses these shortcomings. However, in the view of the authors of this study, it offers an unnecessarily detailed picture considering uncertainties inherent in risk assessments at low doses, as well as uncertainties in the method of interpopulation transfer of radiation risk proposed by the International Commission on Radiological Protection. The aim of this study was to develop and justify a simpler and more straightforward method of presenting information on radiation risks associated with medical X-ray radiological examinations, free from the main drawbacks of the two aforementioned methods. To achieve this goal, radiation risks were calculated using two methods (using effective dose and using the risk model of the International Commission on Radiological Protection). A comparative analysis of the calculation results was conducted with estimates presented in Tables 1-2 of MR 2.6.1.0215-20. As a result of the analysis, an original applied method for presenting qualitative characteristics of radiation risks was developed for use in prescribing X-ray radiological examinations and informing patients about potential health risks. The practical outcome of the study is the formation of a table of radiation risks associated with conducting studies on patients from the Russian population, using the developed method of presenting information on radiation risks.

A model of occupational exposure to gamma flaw detector operators working with portable flaw detectors in the field has been developed. The initial data for the development and verification of the model were the results of measurements of the characteristics of the gamma radiation field at the workplaces of flaw detectors and data from individual dosimetric monitoring. The relationships between the measured (H*(10), Hp(10)) and protection (effective dose) quantities (conversion coefficients) were determined using calculations and phantom experiments simulating three main operations of the full production cycle: transportation of the flaw detector to the place of X-raying of the product, installation of a flaw detector to perform x-raying and X-raying of the product. As a result of the study, it was found that more than 90% of the dose contribution to the readings of an individual dosimeter is due to the installation of the flaw detector in the working position and X-raying of the product. The values of the conversion coefficients for these operations in the form of the ratio of the effective dose values and the readings of dosimeters (Hp(10)) located on the worker's body at chest level (standard place) and abdominal level differ little for both positions of individual dosimeters. The use of maximum conversion coefficient value of 0.8 Sv/Sv corresponding to the operation of X-raying of the product will ensure conservatism in the assessment of the effective dose for the entire production cycle by no more than 15% and 25% for dosimeters located at the chest level and abdominal level, respectively.

Diagnostic reference levels are one of the effective tools for optimizing patient radiation doses in diagnostic radiology. The staff of domestic radiology departments does not have an understanding of the development process and use of diagnostic reference levels during X-ray examinations, although this tool is a generally accepted in practice abroad. The article shows the experience of forming regional diagnostic reference levels based on measurements provided by the accredited testing laboratory of the Scientific and Practical Clinical Center for Diagnostics and Telemedicine Technologies of the Moscow Healthcare Department. The diagnostic reference levels for radiography in Moscow were developed for eight of the most common types of examinations based on the operation of 216 digital X-ray machines. The resulting levels, expressed in the dose-area product (cGy-cm2) and effective dose (mSv), were compared with the local diagnostic reference levels for the Ryazan region, Russia, and national diagnostic reference levels for other countries. The analysis showed continuity in the values. Some types of studies have been optimized. The developed diagnostic reference levels are the quality performance indicators foe diagnostic radiology departments and will be used to optimize a patient radiation dose during diagnostic studies in Moscow.

The paper provides an assessment of the probability and consequences of external events capable of leading to an incident with a breach of established safety barriers restricting the spread of radioactive substances along the coastline of the Techensky reservoir cascade. The initiating events for such an incident could be adverse meteorological conditions resulting in a decrease in the water level in the cascade water bodies below the specified design levels. Drying out the surface of previously inundated sections of the coastline will create an extensive source of atmospheric contamination by technogenic radionuclides during wind-induced resuspension. The probable area of the dried-out sections will be 0.02 — 0.08 kml for reservoir V-3, 0.06 — 0.28 kml for reservoir V-4, 0.19 — 0.90 kml for reservoir V-10, and 0.47 — 2.19 kml for reservoir V-11. The cumulative inventory of 137Cs and 90Sr in the specified area exceeds 105 Bq/ml. The activity released into the atmosphere within an hour will range from 3.69∙108 to 8.48∙1011 Bq for the wind speeds of 5 m/s and 20 m/s, respectively. The probabilities of joint occurrence of strong winds and drought conditions are 6.8∙10-7 per year for a wind speed of 20 m/s and 2.1∙10-3 per year for a wind speed of 5 m/s. The highest values of effective dose for the population of the nearest settlements, reaching 1-3 μSv in the first 10 days and over 200 μSv in the first year, are achieved under extreme wind loads with wind speeds of 20 m/s or more.

Abstract Background One of the most common congenital conditions detected globally, congenital heart diseases, and CT techniques provide a high-quality and thorough presentation of heart anatomy, thoracic vasculature, and extracardiac structures, and hence, it is becoming a more popular non-invasive diagnostic imaging method for congenital heart disease. The drawbacks with CT imaging are the radiation exposure from repeated scans is also rising, especially in young patients. The present study is aimed to evaluate the radiation dose in gated and non-gated cardiac CT for preoperative diagnosis of pediatric patients with congenital heart diseases. Results A total of 111 pediatric patients with mean age of 7.47 years were prospectively included in the study. The mean value of “Effective dose (E)” for gated CT at $$100\;{\text{kV}}_{{\text{p}}}$$ 100 kV p was found to be $$4.71\;{\text{mSv}}$$ 4.71 mSv which is higher than mean “E” of $$3.95\;{\text{mSv}}$$ 3.95 mSv observed for gated CT at $$80\;{\text{kV}}_{{\text{p}}}$$ 80 kV p . The average value of “E” for non-gated technique was observed less than that of gated technique at both $$100\;{\text{kV}}_{{\text{p}}}$$ 100 kV p and $$80\;{\text{kV}}_{{\text{p}}}$$ 80 kV p . The multiple regression analysis shows that “E” is significantly dependent on $${\text{DLP}}\left( {{\text{mGy}}\;{\text{cm}}} \right)$$ DLP mGy cm for both gated and non-gated techniques at 95% level of significance $$\left( {p < 0.05} \right)$$ p < 0.05 . The Student’s t-test verifies that the mean value of “E” for both the techniques at $$100\;{\text{kV}}_{{\text{p}}}$$ 100 kV p and $$80\;{\text{kV}}_{{\text{p}}}$$ 80 kV p are significantly different at 95% level of significance $$\left( {p < 0.05} \right)$$ p < 0.05 . Conclusions The effective dose received by pediatric patients is much higher when using ECG-gated acquisition with an average value of $$4.71\;{\text{mSv}}$$ 4.71 mSv and $$3.95\;{\text{mSv}}$$ 3.95 mSv at $$100\;{\text{kV}}_{{\text{p}}}$$ 100 kV p , and at $$80\;{\text{kV}}_{{\text{p}}}$$ 80 kV p respectively. Because low-voltage X-rays are more sensitive to high atomic number iodinated contrast media, the mean “E” for non-gated cardiac CT imaging at $$80\;{\text{kV}}_{{\text{p}}}$$ 80 kV p is $$2.26\;{\text{mSv}}$$ 2.26 mSv , and results in significant reduction of effective dose.

The article proposes a new approach to assessing the effective doses of flaw detectorists performing flaw detection using portable radionuclide flaw detectors (gamma flaw detectors). The existing approach to assessing effective doses, based on the use of one individual dosimeter placed on work clothes in the chest area, is inadequate for the actual working conditions of exposure of flaw detectorists. Gamma flaw detectors contain a closed man-made source of ionizing radiation in their head, therefore, even in the non-working position, such flaw detectors pose a radiation hazard. When transporting and preparing gamma flaw detectors for work, the flaw detector operator is in close proximity to the radiation source. The irradiation geometry changing during the technological cycle when working with portable gamma flaw detectors at certain stages creates a sharply uneven irradiation of the flaw detectorist’s body. Therefore, after assessing the stages of the technological cycle, an option was proposed for a more conservative assessment of effective doses – to change the location of the individual dosimeter on the working clothes of the flaw detectorist, moving the individual dosimeter to the abdominal area. An anonymous study was carried out with the participation of 15 flaw detectorists; three individual dosimeters were displayed on their working clothes: two of them were experimental and were placed in the chest and abdomen; the third (a control dosimeter) was exposed for the quarter on the chest as part of constant individual dosimetric monitoring. In controlled anonymous measurements, the average effective dose, estimated from the readings of dosimeters exposed in the chest area, was equal to 0,95 mSv (median – 0,92 mSv, maximum value – 1,27 mSv). These values were compared with values obtained using dosimeters that were exposed to the abdomen, and the differences were significant (the average effective dose was 1,24 mSv (median – 1,22 mSv, maximum value – 1,78 mSv).

Abstract Introduction Concerns regarding the adverse consequences of radiation have increased due to the expanded application of computed tomography (CT) in medical practice. Certain studies have indicated that the radiation dosage depends on the anatomical region, the imaging technique employed and patient‐specific variables. The aim of this study is to present fitting models for the estimation of age‐specific dose estimates (ASDE), in the same direction of size‐specific dose estimates, and effective doses based on patient age, gender and the type of CT examination used in paediatric head, chest and abdomen–pelvis imaging. Methods A total of 583 paediatric patients were included in the study. Radiometric data were gathered from DICOM files. The patients were categorised into five distinct groups (under 15 years of age), and the effective dose, organ dose and ASDE were computed for the CT examinations involving the head, chest and abdomen–pelvis. Finally, the best fitting models were presented for estimation of ASDE and effective doses based on patient age, gender and the type of examination. Results The ASDE in head, chest, and abdomen–pelvis CT examinations increases with increasing age. As age increases, the effective dose in head and abdomen–pelvis CT scans decreased. However, for chest scans, the effective dose initially showed a decreasing trend until the first year of life; after that, it increases in correlation with age. Conclusions Based on the presented fitting model for the ASDE, these CT scan quantities depend on factors such as patient age and the type of CT examination. For the effective dose, the gender was also included in the fitting model. By utilising the information about the scan type, region and age, it becomes feasible to estimate the ASDE and effective dose using the models provided in this study.

Abstract Introduction A significant number of head computed tomography (CT) scans are performed annually. However, due to the close proximity of the thyroid gland to the radiation field, this procedure can expose the gland to ionising radiation. Consequently, this study aimed to estimate organ dose, effective dose (ED) and lifetime attributable risk (LAR) of thyroid cancer from head CT scans in adults. Methods Head CT scans of 74 patients (38 males and 36 females) were collected using three different CT scanners. Age, sex, and scanning parameters, including scan length, tube current–time product (mAs), pitch, CT dose index, and dose‐length product (DLP) were collected. CT‐Expo software was used to calculate thyroid dose and ED for each patient based on scan parameters. LARs were subsequently computed using the methodology presented in the Biologic Effects of Ionizing Radiation (BEIR) Phase VII report. Results Although the mean thyroid organ dose (2.66 ± 1.03 mGy) and ED (1.6 ± 0.4 mSv) were slightly higher in females, these differences were not statistically significant compared to males (mean thyroid dose, 2.52 ± 1.31 mGy; mean ED, 1.5 ± 0.4 mSv). Conversely, there was a significant difference between the mean thyroid LAR of females (0.91 ± 1.35) and males (0.20136 ± 0.29) (P = 0.001). However, the influencing parameters were virtually identical for both groups. Conclusions The study's results indicate that females have a higher LAR than males, which can be attributed to higher radiation sensitivity of the thyroid in females. Thus, additional care in the choice of scan parameters and irradiated scan field for female patients is recommended.

Medical diagnostics procedures involving the use of ionising radiation is one of the most intensively developing areas in medical diagnostics. At the same time, medical exposure of patients has a number of fundamental differences from other routine situations of planned exposure. As a rule, medical exposure is acute, and radiation doses in some types of examinations exceed the level of natural and man-made exposure associated with normal operation of radiation facilities. In such a situation, risk differentiation is of great importance, taking into account the different radiosensitivity of individual sex and age groups of patients. Radiation risks should be taken into account both when prescribing examinations involving the use of ionising radiation and when analysing the benefit-harm ratio associated with their application to specific patients. Another reason why risk assessment is an urgent task is the need to inform patients and/or their legal representatives about the health risks associated with the carrying out of examinations, including radiation risks. Within the framework of the present work, the risks associated with fluoroscopic examinations were assessed. To characterise the risk we used the DALY indicator, which is more and more frequently used in risk assessment, reflecting the possible number of lost years of healthy life as a result of radiation exposure during the study. The aim of the work was to calculate DALY values for different sex and age groups of patients from the Russian population during fluoroscopic examinations. To achieve this aim, the method of estimating the number of healthy life years lost due to exposure to ionising radiation, which was developed in the course of the research work, was used. The paper presents the results of calculating DALY values for three types of fluoroscopic examinations. This work represents the next step in the direction of harmonisation of radiation risk assessment methodology with the methodologies of risk assessment of other nature. One of the directions of using the calculation results is the development of methodological approaches to the calculation of sex- and age-dependent risk coefficients associated with medical exposure of patients. The analysis of the obtained results showed that the contribution of oncological diseases to the total radiation harm in older men was significantly higher than in women.

An open plot of virgin land is the reference location in the basic model used to date to estimate the effective dose of external exposure to the population living in a radioactively contaminated area. As our field observations in the Bryansk region of Russia have shown, at present it is very difficult to find truly reference plots of virgin land due to the fact that many virgin meadows were plowed or reclaimed for more than 30 years after the Chernobyl accident. Without special instrumental survey, such disturbed meadow areas can easily be confused with areas of virgin soil. Therefore, the situation with the use of open areas of virgin soil as the reference location has changed dramatically since the first years after the Chernobyl accident. It requires a change in the approach to choosing such a location for the model and/or some revision of the structure of the model itself. Firstly, we propose and justify the use of a permanently cultivated kitchengarden plot as the reference location. The second way to resolve the current difficult situation with the presence of a sufficient number of the virgin soil sites could be excluding the very concept of “reference location” from the model. In this case, when calculating the effective dose of external radiation, it is proposed to directly use the values of the gamma radiation dose rate in the air normalized to the 137Cs contamination density of soil. The values of the normalized dose rate should be experimentally determined in the required time period for each of the locations taken into account in the model.

Abstract Aim Positron emission tomography (PET) using 124I-mIBG has been established for imaging and pretherapeutic dosimetry. Here, we report the first systematic analysis of the biodistribution and radiation dosimetry of 124I-mIBG in patients with neural crest tumours and project the results to paediatric patient models. Methods Adult patients with neural crest tumours who underwent sequential 124I-mIBG PET were included in this retrospective single-center analysis. PET data were acquired 4, 24, 48, and/or 120 h after administration of a mean of 43 MBq 124I-mIBG. Whole-body counting and blood sampling were performed at 2, 4, 24, 48 and 120 h after administration. Absorbed organ dose and effective dose coefficients were estimated in OLINDA/EXM 2.2 according to the MIRD formalism. Extrapolation to paediatric models was performed based on mass-fraction scaling of the organ-specific residence times. Biodistribution data for adults were also projected to 123I-mIBG and 131I-mIBG. Results Twenty-one patients (11 females, 10 males) were evaluated. For adults, the organs exposed to the highest dose per unit administered activity were urinary bladder (1.54 ± 0.40 mGy/MBq), salivary glands (0.77 ± 0.28 mGy/MBq) and liver (0.65 ± 0.22 mGy/MBq). Mean effective dose coefficient for adults was 0.25 ± 0.04 mSv/MBq (male: 0.24 ± 0.03 mSv/MBq, female: 0.26 ± 0.06 mSv/MBq), and increased gradually to 0.29, 0.44, 0.69, 1.21, and 2.94 mSv/MBq for the 15-, 10-, 5-, 1-years-old, and newborn paediatric reference patients. Projected mean effective dose coefficients for 123I-mIBG and 131I-mIBG for adults were 0.014 ± 0.002 mSv/MBq and 0.18 ± 0.04 mSv/MBq, respectively. Conclusion PET-based derived radiation dosimetry data for 124I-mIBG from this study agreed well with historical projected data from ICRP 53. The effective dose coefficients presented here may aid in guidance for establishing weight-based activity administration protocols.

Interventional examinations are associated with high levels of patient exposure per examination, which makes it particularly important to monitor individual patient doses and to assess radiation risks. The aim of this study was the assessment of effective doses for fluoroscopy-guided balloon dilatation of benign esophageal strictures, whichwasperformedonpediatricpatientsaged 1 to 2 yearsatthe Departmentof Radiosurgical Methodsof Diagnosis and Treatment of St. Petersburg State Pediatric Medical University. Patient exposure patterns were basedonourowndatacollection. Thecalculationofeffectiveandorgandosesofpatientsnormalizedbythevalue of the dose area product measured during the study was carried out using PCXMC 2.0 software. The conversion coefficients from the dose area product to the effective dose were calculated using tissue weighting coefficients from the ICRP Publications 60 and 103 their values were 10.7 and 11.7 µSv/cGy cm2, respectively. The results of verification of the method indicated that the use of inappropriate conversion coefficients leads to an almost double underestimation of children’s effective doses. Differences in the values of conversion coefficients are significant and are explained by differences in voltage, source to image distance, and irradiation field size. A simplified model of patient exposure was proposed, which is described by a single irradiation field. The assessment of effective doses using multi-field and single-field irradiation model shows comparable results, which allows using the differentiated approach to the assessment of radiation doses of patients.

adiation risks assessment in medical exposure of patients is one of the mandatory steps in justifying the medical radiological examinations. The main objectives of such assessment are the need for benefit-harm analysis, when prescribing a study, and informing patients or their legal representatives about the radiation risk associated with the recommended examination. The traditional approach to radiation risk assessment is the use of measures based on lifetime morbidity and/or mortality due to radiation exposure in risk characterization. However, the development of the methodology of population health assessment and the need to harmonize the methodology of radiation risk assessment with risks from exposure to factors of other nature imply the use of more informative generalized health indicators in the assessment of exposure to harmful environmental factors. The aim of actual work was to apply the developed methodology of radiation detriment assessment to characterize the risk by calculating DALY (number of years of healthy full life lost due to exposure to ionizing radiation) values for different sex and age groups of Russian patients undergoing computed tomography. To achieve this goal, the previously developed method of estimating the number of years of healthy life lost due to exposure to ionizing radiation was used. Calculations were performed with the use of a specially developed computer program based on the models of the International Commission on Radiological Protection using medical and demographic data of Russian population. The article presents the results of DALY calculation for six types of computed tomographic examinations. The use of DALY to characterize risk instead of the most widely used value of radiation detriment (or lifetime risk of death, relating the harm from the reduction in the quality of life in the case of non-fatal oncological disease) is an attempt to harmonize the methodology of radiation risk assessment with the methodologies of other kind of health risks. One of the directions of calculation results usage is the development of sexand age-dependent risk coefficients associated with medical exposure of patients. The analysis of the obtained results showed that the age distribution of risks agrees well with the data presented in the methodological recommendations MR 2.6.1.0215-20 “Assessment of radiation risk to patients in radiology examinations”. It is also shown that the DALY indicator can serve as a basis for comparative assessment of obtainable and avoidable risks in the field of medical radiation exposure of patients.

The article presents the analysis of the structure of computed tomography diagnostics according to the forms of the federal state statistical observation (radiation-hygienic passports in 2011–2021, forms № 3-DOZ in 2011-2021 and forms № 30 in 2014–2020) in order to assess the status of CT diagnostics in the Russian Federation and identify the main trends in the development of this type of radiation diagnostics and patient doses. In 2011–2021, there was a sharp development of CT diagnostics in the Russian Federation – an increase in the number of CT examinations per 1000 people (up to a factor of 5.9 – from 32 CT examinations per 1000 people to 189 CT examinations per 1000 people) and the contribution of CT in the collective dose from medical diagnostic exposure (3 times from 26% to 77%). The number of CT examinations per 1 CT device from 2014 to 2019 increased by 2 thousand (52%), and in 2020 by another 1.85 thousand (32% compared to 2019) and reached 7.7 thousand. The increase in the number of CT examinations was mainly due to the increased use of CT equipment. The main contribution to the structure and collective dose of computed tomography in 2021 is made by examinations of chest (58%/65%), abdomen (8%/14%), pelvis and hips (3%/4%), skull and maxillofacial area (18%/7%). In 2011-2021 for chest CT examinations, the average effective dose was in the range from 4.2 to 5.9 mSv per examination, for abdomen – from 6.5 to 9.2 mSv, for pelvis and hips – 5 to 6.7 mSv, for skull and maxillofacial area – 1.5 to 2.4 mSv. The COVID-19 pandemic in 2020-2021 caused a change in the structure of CT examinations and collective dose in the Russian Federation – the chest CT examinations occupied the first place of the contribution to the number of examinations and the collective dose. The number of CT examinations per 1000 people and the contribution of CT to the collective dose from medical diagnostic exposure in the Russian Federation were significantly lower than those in foreign countries (up to a factor of 3.5 in the number of CT examinations per 1000 people and up to a factor of 1.6 of the contribution of CT to the collective dose).

Background: The same conversion factors (k-factors) of Single CT (SECT) are applied to estimate the Effective Dose (ED) in Dual Energy Computed Tomography (DECT). However, k-factors for different organs need independently validating for DECT, due to the different conditions in DECT.Objective: This study aimed to calculate organ dose and k-factors in different imaging protocols (liver, chest, cardiac, and abdomen) for male and female phantoms.Material and Methods: This Monte Carlo Simulation study used Monte Carlo N-Particle (MCNP) code for modeling a Siemens Somatom Definition Flash dual-source CT scanner. The organ dose, dose length product, and k-factors were calculated for the Medical Internal Radiation Dose (MIRD) of male and female phantoms.Results: For the male phantom, the k-factors for the liver, chest, cardiac, and abdomen-pelvis imaging protocols are equal to 0.020, 0.012, 0.016, and 0.014 mSv.mGy−1cm−1, respectively. For the female phantom, the corresponding values are equal to 0.026, 0.023, 0.036, and 0.018, respectively. These values for DECT are different from those corresponding values for SECT, especially for the female phantom. Conclusion: The calculated k-factors for DECT can be used as reference values for the estimation of ED in DECT.

Introduction: Radioactive contamination by uranium and its emissions, such as alpha particles, is considered one of the most critical issues affecting the human race and its existence. The study investigated the high ionization capacity number of alpha particles in whole blood samples from cancer patients because these particles have the most significant impact on the shape and function of living cells, modifying them into malignancies. Material and Methods: The TASLImage solid nuclear trace detector CR-39 was used to measure the effects of alpha emitters in the whole blood samples from 40 cancer patients for five types of cancer (breast, uterus, prostate, kidney, and colon) collected from a government hospital at Karbala/Iraq and compared with ten healthy samples. Moreover, the research investigated whether smoking and gender variation affect the outcomes. Results: The radon concentration in whole blood samples from patients and healthy individuals was significantly different (p< 0.05), and it was slightly higher in males with (22.82254±7.38794 Bq/m3). Women with colon cancer had higher blood levels of radon (32.13787±5.79261 Bq/m3) than men with the same malignancy (18.80531±5.63747 Bq/m3), regardless of gender. While the age factor had no noticeable impact, the smoking element had a considerable effect (p< 0.05). Conclusion: All alpha levels were within the (ICRP) usual ranges. Women with colon cancer had the most significant alpha values. In contrast, men with the same disease had the lowest values despite cancer patients' blood levels being higher than those of the healthy group.

Analysis of levels of exposure of public of the Russian Federation by sources of ionizing exposure is one of main parts of the activities conducted by the Federal Service for Surveillance on Consumer Rights Protection and Human Wellbeing. Data on the doses of public of the Russian Federation from medical exposure on facility, regional and federal levels is collected using the form of federal governmental statistical surveillance № 3-DOZ “Data on patient doses from medical X-ray examinations”, that is active since 2000. For the last 20 years there were no significant updates of the form № 3-DOZ. According to the decision of the Board of the Rospotrebnadzor from 11.09.2020, a complex program on update and modernization of form № 3-DOZ was initiated, that has resulted in the approvement of new form № 3-DOZ by the order of Rosstat № 880. The form has been significantly changed to reflect the modern condition of X-ray diagnostics in the Russian Federation. The aim of the current study was to analyze main components of medical exposure dose data collection system that required update and modernization. The study was performed based on the results of assessment of the forms № 3-DOZ from different medical facilities and regions in 2015-2020. The results of the study allowed developing main approaches to the update of the form № 3-DOZ that were implemented in a new edition of the form.

This study is aimed at the analysis of perspectives of provision of radiation safety from natural sources of ionizing exposure on the territories included into the Russian Federation in 2022. The study contains comparison of the requirements of legislative acts and regulations on the radiation safety that were active in 4 new subjects of the Russian Federation (Donetsk and Lugansk republics, Zaporozhye and Kherson regions) on the time of their integration with their Russian equivalents. The results indicate the lack of harmonization between acting radiation safety sanitary acts of the Russian Federation and the Ukraine with recommendations of the international organizations. The study contains results of the surveys on the exposure of the public of the Donbass republics and Zoporozhye region by natural sources of ionizing exposure, analysis of the perspectives of the provision of radiation safety of the public of these regions and the Kherson region. Additionally the study includes the evaluation of the existing legislative base on the protection from natural sources of ionizing exposure in the Russian Federation and perspectives of harmonization with the recommendations of international organizations.

In recent years, an increase in the collective dose from medical exposure has been recorded annually, which is associated with an increase in the availability of high-tech methods of medical care and an increase of their percentage in the structure of X-ray studies. However, any exposure to ionizing radiation on a patient is associated with an increased risk of stochastic effects. The justification principle is the most effective to ensure the radiation safety of patients. The article considers in detail the experiment on the application of the justification principle in medical organizations. The aim of the study was to evaluate the incidence of unjustified referrals to radiological examinations and their impact on the collective effective dose of patients in outpatient medical organizations. As a result, it was ound, that the collective dose from studies with unjustified referrals contributes 21% to the annual collective dose from X-ray studies in outpatient medical organizations. The result obtained confirms the need to ensure the availability of information on clinical recommendations, the accumulated effective dose and patient characteristics in medical information systems, and proves the importance of using this information when prescribing X-ray radiological studies.

After the Chernobyl accident, a certain proportion of agricultural land was withdrawn from normal use due to significant radioactive contamination. Forestry is one of the options currently under consideration to return the abandoned agricultural land to economic circulation in Russia. When using former agricultural land for forestry in radioactively contaminated areas, it is important to have an assessment of the potential radiation doses for forestry workers and the public. The aim of this study was to assess the radiological situation in a young pine forest planted and grown after the Chernobyl accident in the resettlement zone on a former arable field. A nearby old pine forest, which had grown before the Chernobyl accident, was taken for comparison. The study of the radiological situation was performed in the period 1998–2022. In the young forest, 137Cs was fairly evenly distributed in the upper 20 cm soil layer; further with depth, the activity concentration of 137Cs sharply decreased. In the old forest, the maximum activity concentration of 137Cs in the soil was in the top 0–2 cm layer. The activity concentration of 137Cs decreased with depth. In 1998, the average value of the absorbed dose rate in the air from 137Cs+134Cs was lower by a factor of 3 in the young forest compared to the old forest. The difference was associated with differences in the vertical distributions of 137Cs in the soil. Over time, the absorbed dose rate in air from 137Cs+134Cs decreased at both sites with the same effective halftime period of 21.7 year. The activity concentration of 137Cs in the biota (pine trees, edible mushrooms) in the young forest was lower by a factor of 4–30 compared to the old forest. The “forest” component of the external effective dose to adults from the 137Cs source in the young forest was lower by a factor of 3 compared to the old forest. The “forest” component of the internal effective dose from 137Cs was lower by a factor of 10 when eating edible mushrooms from the young forest compared to the old one. In general, the performed study shows that the use of radioactively contaminated abandoned arable land for forestry can be expedient and justified from a radiological point of view.

Abstract Introduction Health professionals in paediatric medical imaging are routinely required to communicate radiation risks to carers and patients. Effective dose alone cannot be used to specify and communicate the radiation risk for an individual as risks are dependent on many factors including age and patient sex. In this study, we estimated typical effective doses for 20 commonly performed paediatric general radiography examinations using the weight‐based imaging protocols employed at a major Australian specialist paediatric hospital. Effective doses were used to estimate and categorise associated age‐based stochastic risks with commonly used risk terminology to facilitate communication of risk. Methods Paediatric protocols for common general radiography examinations and World Health Organization 50th percentile weight‐for‐age data for females and males aged up to 18 years were used to estimate typical effective doses using Monte Carlo software and lifetime risk of cancer incidence using published data. Results were used to determine standardised levels of risk using the Calman risk model. Results Effective doses, corresponding lifetime risk of cancer incidence and level of risk category from 20 general radiography examinations for paediatric patients were calculated and presented for ease of communication. Doses ranged from

Introduction: The purpose of this study was to establish of diagnostic reference level (DRL) and to compare radiation dose between single phase and unjustified double phase abdominopelvic CT imaging. Material and Methods: A total of 163 patients, 85 patients with single phase and 78 patients with unjustified double phase abdominopelvic CT scans, were included in this retrospective study. Volumetric CT dose index (CTDIvol) and dose length product (DLP) were obtained from the CT console. The third quartile of CTDIvol and DLP were determined for diagnostic reference level (DRL). Effective dose (E) and organ dose were obtained using CT-Expo software (version 2.2). Single phase and double phase scans were compared in terms of CTDIvol, DLP, size-specific dose estimate (SSDE), E and organ doses. Results: The institutional DRLs using CTDIvol and DLP for abdominopelvic CT were 9.8 mGy and 571 mGy.cm, respectively. The mean value of E was 5.4 ± 1.8 and 10.3 ± 3.4 for single phase and double phase imaging, respectively, resulting in 4.9 mSv excess dose per patient. Mean value of the DLP was 396.9 ± 142.7 and 759.0 ± 250.7 for single phase and double phase imaging, respectively. E was significantly higher in female compared to male (p < 0.05). Bladder has a highest lifetime attributed risk of cancer incidence among other organs. Also, the cancer risk incidence was higher for female than male. Conclusion: The awareness of physicians about the correct indications of abdominopelvic CT should be increased by using associated reliable guidelines

Abstract Background The aim was to review available biokinetic data, collect own experimental data, and propose an updated compartmental model for 2-[18F]FDG in the frame of the revision of the ICRP report on dose coefficients for radiopharmaceuticals used in diagnostic nuclear medicine. Methods The compartmental model was developed based on published biokinetic data for 2-[18F]FDG. Additional data on urinary excretion in 23 patients (11 males, 12 females) undergoing whole-body PET/CT examinations were obtained within this study. The unknown biokinetic model parameters were derived using the software SAAM II and verified with a modified version of IDAC-Iodide. Dose coefficients for reference adults were calculated with the programme IDAC-Dose 2.1. A dynamic bladder model was employed for urinary bladder dosimetry. Results The proposed model consists of following compartments: blood, heart wall, brain, liver, lungs, pancreas, spleen, kidneys, urinary bladder content and a generic pool compartment “Other”. The latter was introduced to account for 2-[18F]FDG in body organ and tissues besides the explicitly modelled ones. The model predictions showed a good agreement with experimental data. Urinary bladder wall received the highest absorbed dose coefficient of 7.5E−02 mGy/MBq under the assumption of initial urine volume of 100 ml, first voiding at 45 min p.i. and 3.75 h voiding intervals thereafter. The effective dose coefficient calculated according to the current dosimetry framework of ICRP amounted to 1.7E−02 mSv/MBq, compared to 1.9E−02 mSv/MBq in ICRP Publication 128. Conclusion A compartmental model for 2-[18F]FDG was proposed and will be used to replace the descriptive biokinetic model of ICRP Publication 128. The revised model and the provided dose coefficients are expected to improve reference dosimetry for patients administered with 2-[18F]FDG.

The paper presents the values of the conversion coefficients from the operational quantity, HP(10)/ to the protection quantity, effective dose (E). The conversion coefficients were calculated in a number of points located at a depth of 10 mm under the surface of the torso of the computational model MIRD-5 of the body of an adult. The simulated irradiation conditions corresponded to both uniform and sharply non-uniform irradiation of the employee in the fields of photon radiation with the energy from 0.04 to 2 MeV. It was demonstrated that for the uniform radiation and the “typical” location of the individual dosimeter on the employee’s body, the E/HP(10) ratio is less than one in the entire range of radiation energies for the directions of its incidence in front and from the left side, i.e. Hp(10) is a conservative assessment of E. When the radiation falls on the back and for the “typical” location of an individual dosimeter on the employee’s body in the entire range of radiation energies, the ratio E/Hp(10) is significantly larger (for the energies

The study aimed to compute the effective dose (E) and size-specific dose estimate (SSDE) of routine adult patients undergoing thorax and abdominal computed tomography (CT) imaging and to present their multivariate analysis. All adult thorax and abdominal CT examinations conducted from March 2022 to June 2022 were prospectively included in this study. The Water Equivalent Diameter (Dw) and SSDE of all the examinations were computed from CT dose index volume (CTDIvol) and Dose length product (DLP) displayed on the dose report in the CT console. The multivariate statistical analysis was performed to investigate the correlation of SSDE and E on CTDIvol, Dw area of the region of interest (ROI) (AreaROI), body mass index (BMI), conversion factor (fsize) and hounsfield (HUmean) number in the ROI at 95% level of significance (P < 0.05). The linear regression analysis was performed to investigate the dependence of SSDE and E on other parameters for both abdominal and thorax patients. A total number of 135 (Abdomen = 61 and Thorax = 74) measurements were performed. The mean value of effective dose for abdomen and thorax patients was found to be 7.17 ± 3.94 and 4.89 ± 2.16 mSv, respectively. The SSDE was observed to be 13.24 ± 3.61 and 13.04 ± 3.61 mGy for thorax and abdomen respectively. The multivariate analysis suggests that SSDE for abdominal CT is found significantly dependent on CTDIvol, Dw and fsize with P < 0.05 and E is found to be significantly dependent on DLP, AreaROI, Dw and fsize at 95% level of confidence for abdominal CT imaging. SSDE for thorax CT was found significantly dependent on BMI, CTDIvol, HUmean, Dw and fsize at 95% level of confidence. Furthermore, E was observed dependent on DLP at P < 0.05. The linear regression analysis also shows that E is strongly correlated with DLP (r = 1.0) for both thorax and abdominal CT, further the SSDE was observed strongly correlated with CTDIvol with r = 0.79 and r = 0.86 for abdomen and thorax CT respectively. A strong correlation was observed between BMI and for Dw abdominal CT imaging (r = 0.68). The mean value of SSDE for thorax is slightly greater than abdomen. The average value of effective dose for abdomen and thorax measurements was found to be 7.17 ± 3.94 and 4.89 ± 2.16 mSv and , correspondingly. SSDE for both abdomen and thorax CT is significantly dependent on CTDIvol, Dw and fsize at 95% level of confidence. The strong correlation was also observed E on DLP and SSDE on CTDIvol for both Abdomen and Thorax CT. The strong dependence of Dw on BMI (r = 0.68) is due to the excessive fat concentration around the stomach and abdomen.

Abstract Background Since it was first approved in Europe in 2016, the gallium-68 (68Ga) radiopharmaceutical [68Ga]Ga-DOTA-TOC has been widely used for imaging of somatostatin receptor (SSTR) positive tumours using positron emission tomography–computed tomography (PET/CT). Significant patient benefits have been reported, so its use is rapidly increasing. However, few studies have been published regarding occupational doses to nuclear medicine personnel handling this radiopharmaceutical, despite its manual usage at low distances from the skin and the beta-emission decay scheme, which may result in an increased absorbed dose to their hands. In this context, this study aims to analyse the occupational exposure during the administration of [68Ga]Ga-DOTA-TOC for PET/CT imaging. For this purpose, extremity, eye lens and whole-body dosimetry in terms of Hp(0.07), Hp(3) and Hp(10), respectively, was conducted on six workers with both thermoluminescent dosimeters, and personal electronic dosimeters. Results The non-dominant hand is more exposed to radiation than the dominant hand, with the thumb and the index fingertip being the most exposed sites on this hand. Qualitative analysis showed that when no shielding is used during injection, doses increase significantly more in the dominant than in the non-dominant hand, so the use of shielding is strongly recommended. While wrist dosimeters may significantly underestimate doses to the hands, placing a ring dosimeter at the base of the ring or middle finger of the non-dominant hand may give a valuable estimation of maximum doses to the hands if at least a correction factor of 5 is applied. Personal equivalent doses for the eyes did not result in measurable values (i.e., above the lowest detection limit) for almost all workers. The extrapolated annual dose estimations showed that there is compliance with the annual dose limits during management of [68Ga]Ga-DOTA-TOC for diagnostics with PET in the hospital included in this study. Conclusions Imaging with [68Ga]Ga-DOTA-TOC is a safe process for the workers performing the administration of the radiopharmaceutical, including intravenous injection to the patient and the pre- and post-activity control, as it is highly unlikely that annual dose limits will be exceeded if good working practices and shielding are used.

The paper presents results of comparative analysis of the regulatory framework of the Russian Federation with the recommendations and requirements of international organizations in relation to the exposure of population and workers to natural sources of radiation. It is shown that the approaches to radiation safety related to exposure to natural sources of radiation in the Russian regulatory documents are somewhat more consistent with the provisions of the EU Council Directive 2013/59/Euratom than with the recommendations of the IAEA Basic Safety Standards. Analysis of requirements of Russian and international documents is the first step on the way to assess the possibility of implementation of recommendations of international organizations into the Russian regulatory documents and to develop the proposals on harmonization of requirements for control of the exposure of population and workers to natural sources of radiation.

During a stay in a radioactively contaminated forest, a person is inevitably exposed to ionizing radiation from the man-made radionuclides. The purpose of this study was to evaluate the external component of the annual effective dose due to exposure in the forests contaminated following the Chernobyl accident. The study was conducted in the south-western districts of the Bryansk region of Russia in the period 2015–2021. Field (in situ) gamma spectrometric measurements were carried out on 46 forest plots located in the areas of 27 settlements. As of 01.01.2017, the officially established values of soil contamination density with 137Cs in the territory of the settlements themselves were in the range from 33 to 2050 kBq/m2 . According to the field gamma spectrometry, the density of soil contamination with 137Cs on the forest plots varied from 21 to 1930 kBq/m2 . The density of soil contamination with 137Cs in forest was in good agreement with the officially established level of soil contamination with 137Cs in the nearby settlement: the ratio of one indicator to another ranged from 0.70 to 1.32 (mean = 0.94; median = 0.95). The scatter in the measured values of the ambient dose equivalent rate from 137Cs was quite significant: more than one order of magnitude, from 31 to 2700 nSv/h. The variability of the ambient dose equivalent rate from natural radionuclides was relatively small: from 13 to 29 nSv/h. Based on the obtained experimental data and on published values of the duration of human stay in forest, the annual effective dose to selected groups of population was estimated. The dose from natural radionuclides, even in the case of a prolonged stay in the forest (1400 hours per year for foresters), did not exceed 0.02 mSv/year. The estimated values of the effective dose from 137Cs varied very widely from 0.001 to 1.9 mSv/year, depending on the selected forest plot and population group. On the whole, the data obtained indicate that the officially established values of the density of soil contamination with 137Cs in a settlement can be directly used in dosimetric models to estimate the component of the effective dose to a person due to his/her staying in the forest which is located in the area of this settlement. The currently recommended conversion coefficient from the density of soil contamination with 137Cs in a settlement to the ambient dose equivalent rate from 137Cs in the nearby forest is 1.28 (nSv/h)/(kBq/m2 ). To estimate the effective dose from natural radionuclides, it is recommended to use the value of the ambient dose equivalent rate equal to 21 nSv/h.

Mining of minerals increases the risk of exposure to natural radionuclides by exposing them to the outer surface of the earth. The risk increases when these radionuclides are migrated into the bodies of water that have been used for drinking purposes. This work was carried out to assess the radionuclides concentration in drinking water from tin mining areas in North-western Nigeria. Water samples were collected and the activity concentration of 40K, 232Th, 226Ra, and 222Ra were analyzed using a high-purity germanium detector and a liquid scintillation counter respectively. The mean activity concentrations were found to be 3.57 ± 2.1, 4.0 ± 2.2, 7.6 ± 3.7 and 5.8 ± 3.3, 4.4 ± 2.7, 6.2 ± 4.2 Bq/l in surface and groundwater for 226Ra, 232Th, 40K respectively. These values exceeded the recommended value of 1.00 Bq/l in drinking water set by the International Atomic Energy Agency. The activity concentrations of radon varied from 0.75 to 17.08 Bq/L with a mean value of 12.50 Bq/l. The obtained mean value exceeded the recommended value of 11 Bq/l set by the United State Environmental Protection Agency as the level of radon in drinking water. The calculated annual effective dose due to radon and 226Ra, 232Th 40K from the studied water are 2.66 μSv/y and 3.30 μSv/y respectively. These values are lower than the maximum allowable value of 100 μSv/y as a radiation dose received from drinking water set by the World Health Organisation and the United Nations Scientific Committee on the Effect of Atomic Radiations. Therefore, both the surface and groundwater from the study areas can be used for drinking and other domestic purposes as it could pose no significant radiological health hazards.

Attention to the implications of common needle stick injuries has focused heavily on the risk of cross-infection from blood-borne pathogens. An additional risk to the nuclear medicine healthcare worker is that of subcutaneous radioactive contamination from radiopharmaceuticals. This case report provides a rare opportunity to examine the clinical and operator causes of one such event during the dispensing of 99mTc-Tetrofosmin. Contamination monitoring, scintigraphic imaging, and quantification of effective radiation dose provide the level of risk to the operator from the subcutaneous radioactive contamination. Findings demonstrated a very low dose to operator and no deterministic radiobiological effects. Delayed imaging demonstrated negligible biological clearance from the injury site. Implications of the findings for clinical practice are discussed, highlighting the need for a careful and calm approach to radiopharmacy activities.

Abstract Background The rising increase in the incidence of breast cancer among women is worrisome and a great concern to all. More disturbing is that the incidence of breast cancer and death has been attributed to exposure to imaging modalities that utilize ionizing radiation such as computed tomography. The aim of this study was to estimate the lifetime attributable risk (LAR) incidence and mortality for breast cancer for female patients who had head computed tomography in two imaging facilities (centres) in the Niger Delta region of Nigeria. Result The overall estimated mean effective dose in centres G1 and G2 is 5.76 mSv and 1.54 mSv, respectively. There was a statistical significant difference in the mean effective dose between centres G1 and G2 (P

Objective: Reject analysis is usually performed in digital radiography (DR) for quality assurance. Data for computed tomography (CT) rejects remains sparse. The aim of this study is to help provide a straightforward benchmark for reject analysis of both DR and CT. Materials and methods: This retrospective observational study included 107,277 DR and 20,659 CT during 18 months in a tertiary care center. Rejected acquisitions were retrieved by Dose Archiving and Communication System (DACS). The DR and CT reject analysis included reject rates, reasons for rejection and supplementary radiation dose associated with these rejects. Results: 8,904 rejected DR and 514 rejected CT were retrieved. The DR reject rate was 8.3% whereas the CT reject rate was 2.5%. The cumulative effective dose (ED) of DR rejects was 377.3 mSv while the cumulative ED of CT rejects was 1267.4 mSv. The major reason for rejects was positioning for both DR (61%) and CT (44%). Conclusion: This study helps constitute a simple reproducible method to analyze both DR and CT rejects simultaneously. Although CT rejects are less often monitored than DR rejects, the radiation dose associated with CT rejects is much higher, which emphasizes the need to systematically monitor both DR and CT rejects. Investigating the reasons and the most frequently rejected examinations gives an opportunity for improvement of imaging techniques in cooperation with technologists.

The scientific article is devoted to the actual problem of modern medicine – the exposure of the public during multislice spiral computed tomography in the Republic of Uzbekistan. For the period 2017-2020 the number of computed tomography procedures increased from 175000 to 375000 (by a factor of 2), there was an increase in the collective dose from computed tomography from 987,5 to 2482,6 man-Sv (2.5 times). During the study the patient effective doses were calculated and the risks were assessed. The research work was carried out in medical institutions on CT units from different vendors. The examination protocols of 1126 adult patients were analyzed. The patient effective doses during MSCT of various anatomical regions were calculated from the DLP value and their comparative assessment was carried out. The radiation risk assessment was carried out on the basis of the effective dose using the nominal ICRP risk coefficients adjusted for age-related radiosensitivity. According to the results of the studies, it was found that when examining the head area, the effective doses of patients ranged from 1.3 ± 0.3 to 1.9 ± 0.2 mSv, the neck area – from 1.3 ± 0.3 to 2.4 ±0.3 mSv, the chest area – from 5.3 ± 0.7 to 6.6 ± 1,9 mSv, abdomen – from 7.0 ± 1.0 to 8.8 ± 1.6 mSv, small pelvis – from 7.8 ± 1.0 to 10.8 ± 2.5 mSv. The lifetime risk of long-term stochastic effects for the health of a patient from 18 to 65 years old was in the range of 10-4 – 10-3. The results of the study showed that the effective doses differ significantly from each other depending on the anatomical area of study of the patients. A person receives the highest doses of radiation when examining the pelvic and abdominal area, and smaller ones when examining the head area. The difference in the values of effective doses in the study of the same anatomical parts of the human body mainly depended on the weight of the patients, the length of the studied anatomical area, the model of the computer tomograph.

The article presents results of a study on the tritium content in surface and ground waters in the area of peaceful underground nuclear explosions of the “Dnepr” series. Low-yield thermonuclear explosions (1.8–2.1 kt of TNT equivalent) were carried out inside Mount Kuel’por (Khibiny Massif, Kola Peninsula, Murmansk Oblast, the Russian Federation) in 1972 and 1984. The purpose of the explosions was to crush the ore body (apatite minerals), followed by the extraction of the crushed rock to the ground surface. The main long-term problem generated by these explosions was the flow of tritium-contaminated groundwater onto the ground surface. The area where the explosions took place is actively visited by tourists. Water from local reservoirs, in particular from the Kuniyok River, is used by people for drinking. The purpose of this study was to assess the drinkability of the local waters in terms of activity concentration of tritium. To achieve this goal, 35 water samples were taken in 2019 from wells, boreholes, rivers, streams, lakes and other accessible environmental waterbodies. Activity concentration of tritium in the samples was determined using the Quantulus 1220 low-background liquid scintillation spectrometer. The activity concentration of tritium in the water samples was in a rather wide range: from less than 2 Bq/kg up to 1510 Bq/kg. The maximum value was up to three orders of magnitude higher than the regional background level of approximately 2 Bq/kg. At the same time, the maximum activity concentration was significantly lower compared to the intervention level for drinking water (7600 Bq/kg, according to Sanitary Norms and Rules of the Russian Federation). Based on the results of this study and data obtained by other researchers earlier, it became possible to assess the half-time for decrease of activity concentration of tritium in surface and ground waters in the period 2008–2019. The mean value (± standard error of the mean) of the effective half-time of tritium in water from the mine, the boreholes, and the Kuniyok River was estimated as 4.4 ± 0.2 year. The decrease in activity concentration of tritium in water depended more on ecological processes (dilution with “pure” water) than on physical decay of the radionuclide. In 2019, the estimated value of the effective dose due to ingestion of tritium in drinking water from the Kuniyok River was 0.17 μSv; this was negligible compared to the dose limit of 1 mSv per year for the public.

The aim of the study was to develop a methodology that allows taking into account the age and sex dependencies of the risk of radiogenic cancer and the age and sex distribution of the patients to evaluate the collective risk due to separate X-ray examinations and medical exposure in the Russian Federation as a whole. Methodology is based on the use of lifetime risk coefficients estimated for the Russian and Composite population and the results of the study of typical doses of patients for various X-ray examinations in the Russian Federation. It is shown that the assessment of the radiation risk of separate X-ray examinations calculated using lifetime age and sex risk coefficients, organ doses and age distributions of patients may differ up to order of magnitude from the risk assessment based on effective dose and nominal risk coefficients. The difference in estimating of the collective risk of total medical exposure in the Russian Federation by these two methods reached 2.5 times in 2018.

Aims: Calculation of the absorbed dose in human organs is one of the first steps for developing new radiopharmaceuticals. The aim of this study is to estimate the human absorbed dose of a newly developed 68Ga-NODAGA-RGD-BBN radiolabeled compound. Materials and Methods: 68Ga-NODAGA-RGD-BBN was prepared by varying different parameters at optimized conditions. The stability of the radiolabeled peptide in phosphate-buffered saline (PBS) and in human serum was evaluated for 120 min. Afterward, the biodistribution of the complex was assessed in normal and tumor-bearing mice, at least for 120 min postinjection. Finally, the human absorbed dose of 68Ga-NODAGA-RGD-BBN was estimated based on mice data using Radiation Dose Assessment Resource and Spark method. Results: 68Ga-NODAGA-RGD-BBN was produced with radiochemical purity of more than 98% (high-performance liquid chromatography/ radio thin layer chromatography (RTLC)) with high stability in PBS buffer and in human serum at least for 2 h. The complex demonstrated high uptake in gastrin-releasing peptide receptor-expressing tumors compared to other nontarget organs. Furthermore, the dose assessment for the complex showed that the kidneys receive the highest absorbed dose in comparison with other organs. Conclusion: The result of this study showed that 68Ga-NODAGA-RGD-BBN is an effective and radiolabeled ligand for tumor detection, however more studies are still needed.

During last 50 years, firstly in the RSFSR in the USSR (1970-80), then in the Russian Federation - RF (1990-2019), the authors studied the radiation safety issues of patients from medical exposure. The reader is offered a complex radiation-hygienic analysis of the 50-year medical exposure of patients and of the population in Russia to inform and analyze the available data on the most common type of use of ionizing radiation sources in the national economy. For a half century, several generations of people have changed and medical diagnostic X-ray equipment and technologies have also radically changed. The information from this article was obtained on the basis of radiation-hygienic statistics, as well as considered our research. The data is presented at the federal level in the form of the volume of research carried out- determined by the number of X-ray procedures, as well as the level of medical exposure in the form of effective dose of patients in Russia - a huge region with a population of about 150 million people, where about 200 million X-Ray procedures were performed annually, i.e. about 10 billion X-Ray procedures for the entire observation period. During the study, a collective effective dose was - 6.5 million person-Sv at the rate of 100 thousand person-Sv and more per year. The paper presents the dynamics and the structure of the studied indicators depending on the type of medical exposure, as well as its localization. The contribution of the X-ray diagnostics to the total volume of radiation diagnostics, which is developing dynamically, is presented. It was found that throughout the study, there were two oppositely directed processes: an increase in the number of X-Ray procedures and a decrease in the effective doses of patients. At present, the minimum dose has been reached, after that it has been increasing began, associated with the use of new computer technologies. It was determined that, depending on the localization, the main radiation load during X-ray procedures falls on the skeleton and digestive organs. It is shown that during the study period (in 1986) there was an accident at the Chernobyl, which significantly affected on medical activities and, in particular, X-ray diagnostic indicators. The paper shows the consequences of these situations. In general, the data presented is huge in volume and significant in information content. The information obtained on the basis of such a unique data is representative and allows, firstly, to analytically study the issues of radiation protection of patients and, secondly, to plan the strategy and tactics of its development.

Objective: To assess the radiation exposure in cardiovascular implantable electronic device(CIED) implantation procedures, the effect of fluoroscopy frame rate on various radiation exposure indices, and in-hospital outcomes. Methods: Data of CIED implantation procedures from September 2015 to December 2019 of all the CIED implantation procedures performed at our institute were retrospectively analyzed. The procedural data were divided into two groups: a) pre-group: procedures that were performed under fluoroscopy frame rate of 7.5 frames per second(fps); b) post-group: procedures that were performed under fluoroscopy frame rate of 3.75 fps. We compared procedure time, fluoroscopy time, Kerma air product, effective dose, and in-hospital outcomes between the two groups. Results: A total of 2,225 procedures were included in the analysis with mean age of (62 ​± ​15) years. The procedures consisted of the implantation of single-chamber (n ​= ​1,436), double chamber (n ​= ​656), and biventricular devices (n ​= ​133). Procedure time and radiation indices showed a significant reduction over the study period (P ​

Introduction: Whole-body computed tomography (WBCT) is still debatable and a source of excessive radiation exposure when screening individuals with suspected blunt multiple trauma. Objective: This study aims to develop institutional Diagnostic Reference Level's (DRL) value and estimate effective organ doses for poly-trauma patients who underwent WBCT examination. Method: Retrospective analysis for patients undergone WBCT scans after being traumatized and admitted to the emergency room. Effective and organ dose estimated for 78 patients. Sequence parameters and CT indices were retrieved from the CT system. Data analysis was done using SPSS 20.0 (SPSS Inc, Chicago, IL, USA). Results: 84.3% of the patients were male, while 15.7% were female. 88% of the patients had a road traffic accident, and the rest fell from height. The effective dose was estimated as 34.5–35.3 mSv in males and females, respectively, while the organ doses ranged from 10.2 to 63.7 mGy. Conclusion: WBCT is a standard diagnostic radiological tool for urgent evaluation of patients with serious trauma. However, WBCT scanning comes with significant radiation exposure and the risk of developing cancer. Therefore, the WBCT should be clinically justified, and dosage reduction measures should be applied.

The aim of the study was to develop a methodology for assessing radiation risk for patients undergoing medical examinations in the Russian Federation. The methodology is based on the risk model of the ICRP Publication 103, the coefficients of lifetime radiation risk for the Russian population and the results of evaluating the doses of patients in the Russian Federation. For thirty examinations that define about 80% of the collective dose of the population of the Russian Federation from medical exposure, the radiation risk was calculated using «gold standard», — the organ doses and the corresponding sex/age risk coefficients for the Russian population. For other examinations (with the exception of mammography) the values of the risk coefficients normalized on 1 mSv of effective dose, which is the averaged value for four selected anatomical areas of the body: head, neck, chest and abdominal cavity — pelvis, were used. It is assumed that for such examinations the error of risk assessment will increase relative to the error of risk assessment for the aforementioned 30 examinations not more than 30%. It is shown that risk estimates for some examinations calculated using the “gold standard” may differ from such estimates on the base of effective dose and nominal risk coefficients averaged by age and the sex to the order of magnitude.

Objective: To investigate patient-specific radioprotection methods for people in close contact with cancer patients treated by 125I-seed implantation. Methods: The initial dose rates (Ḋ0) at distances of 30 and 100 ​cm from 80 patients who had undergone 125I-seed implantation were measured within 24 ​h of the procedure. The dose rate at t (Ḋt) and effective dose (E) were calculated according to the measured values of Ḋ0. The appropriate precaution times for general adult family members, spouses, coworkers, and children or pregnant women were determined, and the relationships between Ḋ0 and precaution time for different close-contact groups were derived by curve-fitting the corresponding data. Results: The mean Ḋ0 values of 80 patients at distances of 30 and 100 ​cm were (15.24 ​± ​11.25) μSv/h and (1.96 ​± ​2.63) μSv/h, respectively (P ​

Objective: In order to understand the complete scenario of the effectiveness of radiation protection practice in the workplace, especially in the industrial radiography and also to analyze the trends with other related studies, epidemiological studies and legal purposes, the assessment and register of the effective dose plays a significant role. Therefore, efforts have been given in the assessment of collective effective dose, mean effective dose, prediction of lifetime cancer risk, and contribution of different age group workers in the collective effective dose. Methods: The occupational radiation exposures for 472 workers were investigated in industrial radiography throughout Bangladesh from 2015 to 2018 by using thermoluminescent dosimeter (TLD). By using a Harshaw TLD reader (Model-4500), the effective dose was measured in a quarterly basis throughout the year. Based on the value of personal dose equivalent Hp(10), database was prepared and recorded. Results: The collective effective dose was 36.1, 40.7, 28.8 and 37.5 man·mSv among 105, 102, 100 and 165 radiation workers in 2015, 2016, 2017 and 2018, respectively. The maximum effective dose received by radiation workers was 6.0, 7.1, 6.9 and 19.9 ​mSv in 2015, 2016, 2017 and 2018, respectively, which remained within the stipulated dose limits imposed by Nuclear Safety and Radiation Control (NSRC) Rules-1997, Bangladesh and International Commission on Radiological Protection (ICRP-103). Conclusion: This kind of monitoring would help to construct a national database that will be used by the end users to improve their implementation of optimization in occupational radiation protection in industrial radiography.

Abstract This review presents basic information on the dosimetric quantities used in medical imaging for reporting patient doses and establishing diagnostic reference levels. The proper use of the radiation protection quantity “effective dose” to compare doses delivered by different radiological procedures and different imaging modalities with its uncertainties and limitations, is summarised. The estimates of population doses required by the European Directive on Basic Safety Standards is commented on. Referrers and radiologists should be familiar with the dose quantities to inform patients about radiation risks and benefits. The application of effective dose on the cumulative doses from recurrent imaging procedures is also discussed. Patient summary: Basic information on the measurement units (dosimetric quantities) used in medical imaging for reporting radiation doses should be understandable to patients. The Working Group on “Dosimetry for imaging in clinical practice” recommended that a brief explanation on the used dosimetric quantities and units included in the examination imaging report, should be available for patients. The use of the quantity “effective dose” to compare doses to which patients are exposed to from different radiological procedures and its uncertainties and limitations, should also be explained in plain language. This is also relevant for the dialog on to the cumulative doses from recurrent imaging procedures. The paper summarises these concepts, including the need to estimate the population doses required by the European Directive on Basic Safety Standards. Referrers and radiologists should be familiar with the dose quantities to inform patients about radiation risks and benefits.

Abstract Purpose A 2-m axial field-of-view, total-body PET/CT scanner (uEXPLORER) has been recently developed to provide total-body coverage and ultra-high sensitivity, which together, enables opportunities for in vivo time-activity curve (TAC) measurement of all investigated organs simultaneously with high temporal resolution. This study aims at quantifying the cumulated activity and patient dose of 2-[F-18]fluoro-2-deoxy-D-glucose (F-18 FDG ) imaging by using delayed time-activity curves (TACs), measured out to 8-h post-injection, for different organs so that the comparison between quantifying approaches using short-time method (up to 75 min post-injection) or long-time method (up to 8 h post-injection) could be performed. Methods Organ TACs of 10 healthy volunteers were collected using total-body PET/CT in 4 periods after the intravenous injection of F-18 FDG. The 8-h post-injection TACs of 6 source organs were fitted using a spline method (based on Origin (version 8.1)). To compare with cumulated activity estimated from spline-fitted curves, the cumulated activity estimated from multi-exponential curve was also calculated. Exponential curve was fitted with shorter series of data consistent with clinical procedure and previous dosimetry works. An 8-h dynamic bladder wall dose model considering 2 voiding were employed to illustrate the differences in bladder wall dose caused by the different measurement durations. Organ absorbed doses were further estimated using Medical Internal Radiation Dose (MIRD) method and voxel phantoms. Results A short-time measurement could lead to significant bias in estimated cumulated activity for liver compared with long-time-measured spline fitted method, and the differences of cumulated activity were 18.38% on average. For the myocardium, the estimated cumulated activity difference was not statistically significant due to large variation in metabolism among individuals. The average residence time differences of brain, heart, kidney, liver, and lungs were 8.38%, 15.13%, 25.02%, 23.94%, and 16.50% between short-time and long-time methods. Regarding effective dose, the maximum differences of residence time between long-time-measured spline fitted curve and short-time-measured multi-exponential fitted curve was 9.93%. When using spline method, the bladder revealed the most difference in the effective dose among all the investigated organs with a bias up to 21.18%. The bladder wall dose calculated using a long-time dynamic model was 13.79% larger than the two-voiding dynamic model, and at least 50.17% lower than previous studies based on fixed bladder content volume. Conclusions Long-time measurement of multi-organ TACs with high temporal resolution enabled by a total-body PET/CT demonstrated that the clinical procedure with 20 min PET scan at 1 h after injection could be used for retrospective dosimetry analysis in most organs. As the bladder content contributed the most to the effective dose, a long-time dynamic model was recommended for the bladder wall dose estimation.

The aim of the study was to estimate the patient effective doses from hepatic arterial chemoembolization. The study was based on the parameters of the protocols of liver chemoembolization collected for 67 patients in Angiography department of the «A.M. Granov Russian Scientific Center of Radiology and Surgical Technologies» of the Ministry of Health of the Russian Federation. The parameters were collected using a dedicated questionnaire and exported from digital image files in DICOM format with preliminary anonymization. The simulation of patient exposure was performed using PCXMC 2.0 software. The median values of the patient dose-related quantities (minimum and maximum values) were as follows: total dose–area product – 6.1 Gy×cm2 (3.4-693Gy×cm2), fluoroscopy time – 7.5 min (2.0-28.3 min), effective dose – 11.7 mSv (0.6-132 mSv). For three patients effective doses exceeded 100 mSv. In two cases, total dose-area product exceeded the control values for deterministic effects in the skin. No tissue reactions were identified for the whole patient sample.

In April 2020 we commemorate the 90th birthday of the major scientist, doctor of technical sciences, Professor Eduard Mechislavovich Krisiyk. A new field of research on radiation-hygienic assessment of the natural sources of ionizing exposure and limitation of the public exposure has been developed under his scientific supervision and personal participation. For the first time in the international practice E.M. Krisiyk as the main author developed the requirements for the concentration of the natural radionuclides in the building materials; as the co-author – in phosphoric fertilizers, indicated the necessity of their radiation control. His scientific results were included into various Russian legislative and methodical documents: Federal state law “On the radiation safety of the public” in 1996, Norms of the radiation safety NRB-96 and NRB-99, Basic sanitary rules on the provision of the radiation safety OSPORB-99, Federal targeted program “Radon”, various guidelines. His scientific school, his flock and followers are successfully developing the scientific-methodical basics of the regulation of the natural exposure of the public of the Russian Federation at the current stage.

Radionuclide therapy with 223Ra-dichloride is used to treat bone metastases and to improve the quality of life of patients with metastatic castration-resistant prostate cancer. At the present time there is no reliable data on the biodistribution of the 223Ra-dichloride in the patient body. The aim of this study was to assess absorbed, equivalent doses in radiosensitive organs and tissues and effective dose from internal exposure for patients with metastatic castration-resistant prostate cancer treated with 223Ra-dichloride. Internal doses from 223Ra-dichloride were calculated for a chamber model specific for patients with metastatic castration-resistant prostate cancer. This model consists of 8 chambers (blood plasma, two chambers describing bone tissue, small intestine, upper large intestine, lower large intestine, feces and the rest of the body). Time-integrated activities were calculated using the SAAM II v2.3 software. The IDAC-Dose 2.1 software was used to calculate the absorbed doses. The highest absorbed doses in organs and equivalent doses were determined for the bone surface and red bone marrow. The absorbed dose from a-radiation in the bone surface for a set of six therapeutic procedures with 223Ra-dichloride was estimated as 1 Gy; in the red bone marrow — 0.14 Gy. However, the approach used does not specifically consider accumulation of the radiopharmaceutical in metastases, which can lead to a significant overestimation of the absorbed dose in the healthy part of the bone surface and red bone marrow.

The purpose of this work is to investigative radiation protection of the female breast in different X-ray examinations, including radiography. It is actual, because Publication ICRP №103 takes female breast to maximum irradiating organs. Analysed: risk of ionizing radiation, FB cancer, volume and dynamics X-ray examinations, female breast organ dose and effective dose. In conformity with data of Publication ICRP №103, effective dose of patients at mammography increased in 2,4 time and reach 0,48 mSv for examination as compared with 0,20 mSv with data of Publication ICRP №60. It is shown, that among different cancer, female breast cancer takes first place and constancy increased. Quantity of mammograms for 10 years increased in 2 time and collective dose increased in 2 times at last 7 years. Female breast average organ dose in mammography is 0,96 mGy and effective dose 0,05 mSv. It is only a part of summary irradiation from all X-ray examinations. The average mean value female breast organ dose of all radiography is 1,84 mGy (anterio-posterior projection – 1,57 mGy, lateral – 2,91 mGy) and effective dose – 0,25 mSv (anterioposterior – 0,26 mSv, lateral – 0,17 mSv). Considerable female breast irradiation is caused by X-ray spine examinations (thorax and lumbar). It is necessary to ensure radiation protection of female breast in diagnostic radiology, including quality control and optimization. Also need to shut female breast by X-ray protection apron, particularly in the lateral projection.

The paper is devoted to the verification of the model of external exposure of the Japanese population from radioactive fallout after the accident at the “Fukushima-1” NPP published by UNSCEAR in 2014. The paper presents specific quantitative examples of the verification of the external exposure model of the Japanese population after the accident at the “Fukushima-1” nuclear power plant. As an independent set of experimental data for validation of the model estimates we used the results of measurements of individual doses of external radiation in various population groups in Japan in different time periods after fallout. In the case of the deterministic version of the model, it was shown that for the adult population working mainly outdoors (construction workers and agricultural workers), the differences between the average values of effective doses predicted by the model and those obtained on the basis of measurements were less than 20%. For office workers, this difference was larger, from 34 to 70%, depending on whether their office buildings are wooden or multi-story concrete. For children under 16 years of age and a longer period of time for measuring individual doses after radioactive fallout (2011 – 2015), the differences between the model average effective doses and those estimated on the basis of measurements ranged from –24% to +32% in different time periods. In the case of the stochastic version of the model, it was shown that for the three considered groups of the adult population the distributions of individual doses obey the logarithmically normal law and the differences in the values of the calculated and experimental geometric means ranged from –7% to +20%. The geometric standard deviation values obtained in the simulation were always slightly higher than the similar values estimated based on the measurement results.