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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.

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.

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.

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).

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.

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.

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.

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 aim of the current study was to perform a comparative assessment of the radiation and non-radiation health risks for the sample of transgenders as well as the assessment of their perception of these risks. The study was performed on the sample of patients, undergoing the gender reassignment surgery from female to male. The structure of surgical procedures and the corresponding X-ray examinations was analyzed with the subsequent assessment of the radiation and non-radiation health risks. The level of patient knowledge on the risks and benefits of the medical procedures and perception of the ratio of radiation and non-radiation risks were evaluated based on the results of the sociological study. The study included the patients that underwent gender reassignment surgery in August 2012 – February 2018 on the base of I.M. Sechenov First Moscow State Medical University. Data collection and questioning were performed in August 2019 – March 2020. Data on the structure of the surgical procedures and X-ray examinations was collected for 99 patients; 86 patients agreed to participate in the questioning. The results indicate that the selected sample of patients, undergoing the gender reassignment surgery from female to male, is a high risk group both for radiation and non-radiation factors. For the whole multi-stage gender reassignment surgery, a patient could receive a total effective dose up to 250 mSv due to repeated computed tomography scans of chest, abdomen and head with contrast, corresponding to the lifetime attributive radiation risk of up to 1×10-2. Comparison of radiation and non-radiation risks for that patient sample indicates the dominance of the risk of successful suicide attempts (5×10-2). Radiation risks are equal to or even exceed (for the final stages of the gender reassignment surgery) the other risks of mortality from the non-radiation factors (anesthesia – 5,4×10-5, thrombosis – 2×10-5, post-surgical complications – 6×10-2). The reduction of suicide risks, as a result of the treatment, outweighs all other risk factors and justifies the gender reassignment surgery. The results of a sociological study show a decrease from 77% to 23% of suicidal thoughts among the patients. The study indicates that risk-communication was performed on the unsatisfactory level: less than 40% of the patients were informed about the possible health risks during the treatment; less than 50% of respondents knew about the benefits of X-ray examinations. About 70% of the patients rate their current problems with health higher compared to the risks from diagnostics and surgery. It explains the lack of interest to the radiation risk.

High levels of tuberculosis morbidity in the Russian Federation lead to the extensive use of X-ray diagnostics for the tuberculosis screening and assessment of the effectiveness of treatment. Digital radiography and computed tomography are traditionally used for the diagnostics of tuberculosis. These methods are associated with significant drawbacks: low specificity for radiography, high costs per examination, significant patient doses, and limited availability for computed tomography. As an additional method for the assessment of the effectiveness of the tuberculosis treatment it is possible to use linear tomography performed on the digital X-ray units. The aim of the current study was to evaluate the possibility of utilization of the digital linear tomography for the control of the effectiveness of tuberculosis treatment in a dedicated antitubercular medical facility. The study was divided in two stages. The first stage was aimed at the assessment of the diagnostic image quality of the digital linear tomograms obtained using the previously developed low-dose imaging protocols. Image quality assessment was performed using an anthropomorphic chest phantom and dedicated imitators of the lung lesions. Image quality was assessed by the experts (radiologists) based on the developed image quality criteria. Results of the first stage of the study indicate that all low-dose protocols allow obtaining images with at least acceptable image quality. Hence it was possible to propose low-dose protocols for clinical evaluations. The second stage of the study was performed as a prospective cohort survey aimed at the evaluation of the structure of X-ray examinations, patient doses and clinical image quality of the digital linear tomograms in antitubercular early treatment center. The cohort survey included two patient samples, uniform by age and gender composition, anthropometric characteristics and structure of diagnosis. One of the samples was imaged using standard (vendor) digital linear protocols, other – using the proposed low-dose protocols. Dose data collection (measurement of dose-area product and subsequent calculation of effective dose) and expert image quality assessment was performed for each patient. The results of the second stage of the study indicate that the use of the low-dose protocols allow reducing the patient effective doses per examination up to a factor of 6–8 (0.56 – 5.9 mSv for standard protocols; 0.2 – 1.15 mSv for low-dose protocols) due to the reduction in tube current-time product (126 mean mAs and 11 mean mAs, respectively). The dose reduction is accompanied by the reduction in the image quality of the linear tomograms (from “excellent” or “good” for standard protocols to “acceptable” for low-dose protocols). However, that dose not hinder the conclusion decision and identification of pathologies. Results of the study indicate that digital linear tomography can be used for the evaluation of the dynamics of the pathological process in the lungs with the previously defined localization of the pathology. The presented low-dose protocols were implemented into radiological practice of the antitubercular early treatment center. Currently, the proposed low-dose protocols are under evaluation for the large-scale study on the base of general practice hospitals

The current study was aimed at the justification and proposal of the supplements and corrections that are planned for the implementation in the updated version of the Methodical guidelines “Control of the effective doses of the patients from the X-ray examinations” (MU 2.6.1.2944-11). This study included estimation and/ or update of the values of the conversion coefficients from measurable dose characteristics (entrance-surface dose, dose-area product) to the effective dose for various X-ray examinations. Estimation of the updated conversion coefficients was based both on the home analytical and experimental studies based on the modern protocols of the X-ray examinations, and the results of the published data. Updated values of the conversion coefficients were presented for: fluoroscopic examinations of the gastro-intestinal tract with barium media for adult and pediatric patients; interventional examinations of the adult patients; computed tomography examinations for adult and pediatric patients; dental intraoral examinations. For the first time, the methods of the estimation of the effective dose and corresponding conversion coefficients were presented for: computed tomography of the extremities, whole body, scan of several anatomic regions; angiographic examinations of the heart vessels of the pediatric patients of different age categories; slot-scanning X-ray examinations; bone densitometry.

Implementation of modern highly informative methods of X-ray diagnostics (computed tomography, interventional examinations, nuclear medicine), associated with the increase of doses to the public and patients, requires the development and improvement of the existing system of the radiation protection from medical exposure. Despite the prevalence of the traditional imaging modalities in the structure of X-ray diagnostics in the Russian Federation (radiography and fluorography compose up to 95% out of 280 mln. X-ray examinations performed in 2017), the major contribution into the collective dose from medical exposure is due to the computed tomography (50,5%). Comparison of the structure of X-ray diagnostics in the Russian Federation with European Union indicates the absence of fluorography examinations and significantly (up to a factor of 5) higher contribution of computed tomography in European countries. An average collective dose from medical exposure in European countries is composed of 80% of computed tomography and of 10% of nuclear medicine; a mean effective dose per X-ray examination are higher up to a factor of 3 compared to Russia. The analysis of the trends of the development of the X-ray diagnostic in the Russian Federation allows predicting a further increase of the number of computer tomography, interventional and nuclear medicine examinations as well as an increase of the collective dose from medical exposure up to a factor of two in the next decade. This will be associated with changes in the structure of the X-ray diagnostics and an increase of the mean effective doses from X-ray examinations.

Fluoroscopic examinations of the upper gastro-intestinal tract and, especially, barium meal examinations, are commonly performed in a majority of hospitals. These examinations are associated both with substantial individual patient doses and contribution to the collective dose from medical exposure. Effective dose estimation for this type of examinations is complicated due to: 1) the necessity to simulate the moving X-ray irradiation field; 2) differences in study structure for the individual patients; 3) subjectivity of the operators; and 4) differences in the X-ray equipment. The aim of the current study was to estimate conversion coefficients from dose-area product to effective dose for barium meal examinations for the over couch and under couch exposure conditions. The study was based on data collected in the X-ray unit of the surgical department of the St-Petersburg Mariinsky hospital. A model of patient exposure during barium meal examination was developed based on the collected data on fluoroscopy protocols and adult patient irradiation geometry. Conversion coefficients were calculated using PCXMC 2.0 software. Complete examinations were converted into a set of typical fluoroscopy phases and X-ray images, specified by the examined anatomical region and the projection of patient exposure. Conversion coefficients from dose-area product to effective dose were calculated for each phase of the examination and for the complete examination. The resulting values of the conversion coefficients are comparable with published data. Variations in the absolute values of the conversion coefficients can be explained by differences in clinical protocols, models for the estimation of the effective dose and parameters of barium meal examinations. The proposed approach for estimation of effective dose considers such important features of fluoroscopic examinations as: 1) non-uniform structure of examination, 2) significant movement of the X-ray tube within a single fluoroscopic phase, and 3) the variety of exposure geometries within complete examination.

Objective: to search for the possibility of lowering a dose burden on a patient during preventive chest radiography.Material and methods. The investigation was carried out in two hospitals (City Mariinsky Hospital, Saint Petersburg, Russia) and (Skane University Hospital, Malm ° ö, Sweden) in 2013–2015. The existing protocols for this type of investigation were corrected by changing the anode voltage, the thickness of complete filtration, and the refusal to use a raster to determine the optimal dose/image quality ratio.Results. The investigation showed the possibility of reducing the values of the products of the dose per area (PDA) by 47% and lowering the effective dose (ED) by 33%, by increasing the tube voltage (up to 125 or 150 kV) and decreasing the thickness of full filtration of direct beam radiation (to 3 mm Al). The refusal to use a raster could further reduce the value of PDA and ED to 75%.Conclusion. Comparison of the dose values of Russian and Swedish X-ray apparatuses showed that the absolute values of PDP and ED are 10 times lower for Swedish devices in the same modes of chest radiography. This fact can be explained by the use of various image receivers and automatic exposure control settings.

Diagnostic reference levels are the main and the most effective tools of optimization of the radiation protection of patients from medical exposure. Diagnostic reference levels should be established based on the results of dedicated dose surveys, allowing evaluating typical patient dose distributions in a selected dose quantity for the selected X-ray examinations. The aim of the current study was to assess the distributions of typical effective doses in representative Russian regions. Materials and methods: Typical patient effective doses for the 13 most common radiographic X-ray examinations were collected in 203 X-ray rooms in 101 hospitals in six regions of Russian Federation in 2009–2014. A differentiated approach was used for the estimation of the typical effective doses depending on the image acquisition technology. Effective doses were estimated using «EDEREX» (Russia) computational software. Results and discussion: Results of the dose data analysis indicate the lack of significant differences between the distributions of the typical effective doses between the selected regions, allowing merging the regional samples and further evaluating the pooled (joint) sample. A significant ratio of maximum to minimum (up to two orders of magnitude) due to a presence of X-ray units with abnormally high and low typical effective doses was observed for all 13 selected X-ray examinations. Abnormally high typical effective doses can be explained by performing the examinations using high values of tube current-time product (150–600 mAs) on a maximum field size (up 40×40 cm). Removal of the typical effective doses below 5%-percentile and above 95%-percentile of typical effective dose distributions for all examinations would result in a reduction of a mean effective dose by up to 30% and reduction of a 75%-percentile of the distributions by up to 15%. No significant differences between the distributions of TED for analogue and digital X-ray units were observed for the pooled sample for selected examinations except for the examination of the chest in posterior-anterior projection. Conclusions: These results should be considered in the process of establishing and implementing DRLs as well as in the cost-benefit analysis of the optimization in radiography.

The modern approach to the radiation protection of the patients from medical exposure is mainly based on the principle of optimization using diagnostic reference levels. Implementation of diagnostic reference levels and optimization in Russian radiological practice is limited due to lack of methodology of data collection and patient dose assessment, investigation and management of abnormally high and low patient doses. Current study is focused on the justification of the diagnostic reference levels concept and practical aspects of establishment of diagnostic reference levels for common radiographic X-ray examinations and their use in clinical practice. It is proposed to establish diagnostic reference levels as the 75%-percentiles of X-ray unit distributionby the patient standard doses for a given X-ray examination. Methodology for standard doses assessment is presented for different types of X-ray units. Based on the results of dose data collection in different regions of the Russian Federation in 2009–2014, the national diagnostic reference levels values are estimated in terms of effective dose for the radiographic examinations of skull, chest, cervical, thoracic and lumbar spine,abdomen and pelvis. The methodology of the optimization process is developed for the hospital use. It includes a comparison of the patient standard doses with the national diagnostic reference levels, investigation and correction of abnormally high and low patient doses. A list of corrective measures is proposed: from additional training of the staff and manual adjustment of the parameters of examinations to the replacement of an X-ray unit. It is conferment that even a limited implementation of the optimization methodology would allow to reduce standard doses with a factor of 1,5.

Saint-Petersburg Institute of Radiation Hygiene has undertaken in 2009-2010 selective regional study of exposure levels of adult patients during radiological diagnostic procedures in 20 hospitals of the city Saint-Petersburg and the Leningrad region. We examined 52 X-ray machines, 14 computed tomography rooms and 9 angiography rooms. The average effective doses, depending on the technology and type of patient examination, varied within the following limits: routine radiographic procedures - from 0.05 mSv to 0.6 mSv, computed tomography procedures - from 0.6 to 17.5 mSv, interventional examinations - from 6 to 60 mSv. The obtained effective doses of the patients in the studied hospitals of Sant-Petersburg and Leningrad region are compared with the average values recommended in the statistical form 3-DOS, and with published foreign data.

We introduce a system of Diagnostic Reference Levels (DRLs) for patients medical exposure for national health care practice implementation. DRLs are an effective way of the patient radiation protection through the optimization of the medical exposure. The paper discusses and compares different methods of determining the DRLs based on measured and/or calculated quantities of patient’s dose: dose area product (DAP), entrance surface dose (ESD) and an effective dose. Distributions of different dose quantities in different Saint-Petersburg clinics are shown on the example of chest PA examinations. The results are compared with the data from other sources. Regional DRLs for Saint-Petersburg are proposed.

This study is devoted to the assessment of the relations between the digital chest x-ray screening procedure parameters, different dose quantities (DAP, ESD, Effective dose) for different age and gender patient groups and patient’s anthropometric indicators. We selected the anthropometric indicators with the maximum impact on patient’s doses. We propose a new approach for the determination of the standard patient to be used for the medical exposure protection optimization using DRLs.

The form of federal governmental statistical surveillance № 3-DOZ, titled “Data on patient doses from medical X-ray examinations,” has changed significantly by the order of Rosstat N 880. In particular, the structure of the form’s has been revised: studies involving high doses were dedicated from the rest; the section on radionuclide diagnostics has been redesigned; the information on the levels of patient exposure when using individual radionuclides and in hybrid studies have been displayed; information on the number of radiological studies and collective doses for pediatric patients have been introduced; and the number of studies for which typical (average) effective doses of patients are presented has been reduced. The structure of the updated form № 3-DOZ is presented within the framework of this work. In this article, recommendations for filling out № 3-DOZ have been developed in order to increase the reliability of the data provided and reduce the number of procedural errors. This work is a continuation of the article Vodovatov A.V., Chipiga L.A., Bratilova A.A., Druzhinina P.S., Shatskiy I.G., Petryakova A.V., Sarycheva S.S., Biblin A.M., Akhmatdinov R.R., Kapyrina Yu.N., Soldatov I.V., Puzyrev V.G., and Ryzhov S.A. “Update of the federal governmental statistical surveillance form № 3-DOZ “Data on patient doses from medical X-ray examinations”. Perquisites for the update, published in the journal Radiatsionnaya Gygiena (2023. Vol. 16, N 2. P. 126–136. DOI: https://doi.org/10.21514/1998-426X-2023-16-2-126-136).