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Objective: Early 2018, the new eye lens dose limit of 20 mSv per year for occupational exposure to ionising radiation was implemented in the European Union. Dutch guidelines state that monitoring is compulsory above an expected eye lens dose of 15 mSv/year. In this study we propose a method to investigate whether the eye lens dose of interventionalists would exceed 15 mSv/year and to determine if the eye lens dose can be derived from the regular personal dosimeter measurements. Methods: The eye lens dose, Hp(3), of interventional radiologists (n = 2), cardiologists (n = 2) and vascular surgeons (n = 3) in the Máxima Medical Centre, The Netherlands, was measured during six months, using thermoluminescence dosimeters on the forehead. Simultaneously, the surface dose, Hp(0,07), and whole body dose, Hp(10), were measured using regular dosimeters outside the lead skirt at chest level. The dosimeters were simultaneously refreshed every four weeks. The eye lens dose was compared to both the body-worn dosimeter values. Measurements were performed in the angiography suite, Cath lab and hybrid OR. Results: A clear relation was observed between the two dosimeters: Hp(3) ≈ 0,25 Hp(0,07). The extrapolated year dose for the eye lens did not exceed 15 mSv for any of the interventionalists (average 3 to 10 studies/month). Conclusions: The eye lens dose can be monitored indirectly through the regular dosimeter at chest level. Additionally, based on the measurements we conclude that all monitored interventionalists remain below the dose limit and compulsory monitoring limit for the eye lens dose.

In this research, a comprehensive code called KIANA is developed based on the Gaussian plume model to simulate and predict the radiological consequences received through all the possible, reasonable, probable, and standard exposure pathways for NPPs and chemical facilities. To validate the KIANA code, a case study is modeled for Bushehr Nuclear Power Plant Unit One (BNPP-1), and the KIANA code results are compared with the results of the Final Safety Analysis Report (FSAR-2017) data of BNPP-1. To assess the performance of the KIANA code, the total dose due to the airborne pathway in accident conditions including small break LOCA (SBLOCA), large break LOCA (LBLOCA), and equivalent exposure dose for the thyroid gland of a group of infants and children age 1 to 8 y at BNPP-1, are investigated. The KIANA code results show that the total effective doses do not exceed the regulatory limit of 5 mSv for external and internal exposures and the regulatory limit of 50 mSv for thyroid equivalent dose. The KIANA code results indicate good agreement with the results of FSAR-2017.

In nature, each mineral grain (quartz or feldspar) receives a dose rate (Dr) specific to its environment. The dose-rate distribution therefore reflects the micro-dosimetric context of grains of similar size. If all the grains were well bleached at deposition, this distribution is assumed to correspond, within uncertainties, with the distribution of equivalent doses (De). The combination of the De and Dr distributions in the De_Dr model proposed here would then allow calculation of the true depositional age. If grains whose De values are not representative of this age (hereafter called “outliers”) are present in the De distribution, this model allows them to be identified before the age is calculated, enabling their exclusion. As the De_Dr approach relies only on the Dr distribution to describe the De distribution, the model avoids any assumption about the shape of the De distribution, which can be difficult to justify. Herein, we outline the mathematical concepts of the De_Dr approach (more details are given in Galharret et al., 2021) and the exploitation of this Bayesian modelling based on an R code available in the R package “Luminescence”. We also present a series of tests using simulated Dr and De distributions with and without outliers and show that the De_Dr approach can be an alternative to available models for interpreting De distributions.

The rapid rise in the application of novel treatment techniques, such as intensity-modulated radiotherapy (IMRT), motivated us to survey the status of Korea's radiation safety management and the shielding designs of facilities employing medical linear accelerators (LINACs). To this end, a questionnaire was used to collect information on LINAC facilities and treatments, workload, shielding design, shielding management, and path of obtaining shielding information. Out of 100 domestic institutions, 52 responded to the survey. Approximately 70% of the institutions utilized IMRT for more than 60% of their cases, and an IMRT factor of 5 was adopted by 75% of these institutions. Over 80% of the institutions accounted for the applied time-averaged dose rate per week and instantaneous dose equivalent rates in their shielding designs. Approximately 45% of the institutions obtained important shielding information via a radiation shielding design company and the NCRP-151 report. Overall, most facilities were shown to follow the standards recommended by the relevant international agencies. However, the requirement to establish standardized shielding design information and clarify ambiguous paths for information acquisition was also highlighted. Therefore, the study's results can be used as a foundation for establishing a safety control system and for creating adequate shielding designs.

High risk prostate cancer (HR-PrCa) is a subset of localized PrCa with significant potential for morbidity and mortality associated with disease recurrence and metastasis. Radiotherapy combined with Androgen Deprivation Therapy has been the standard of care for many years in HR-PrCa. In recent years, dose escalation, hypo-fractionation and high precision delivery with immobilization and image-guidance have substantially changed the face of modern PrCa radiotherapy, improving treatment convenience and outcomes. Ultra-hypo-fractionated radiotherapy delivered with high precision in the form of stereotactic body radiation therapy (SBRT) combines delivery of high biologically equivalent dose radiotherapy with the convenience of a shorter treatment schedule, as well as the promise of similar efficacy and reduced toxicity compared to conventional radiotherapy. However, rigorous investigation of SBRT in HR-PrCa remains limited. Here, we review the changes in HR-PrCa radiotherapy through dose escalation, hypo- and ultra-hypo-fractionated radiotherapy boost treatments, and the radiobiological basis of these treatments. We focus on completed and on-going trials in this disease utilizing SBRT as a sole radiation modality or as boost therapy following pelvic radiation.

Biological modeling for anti-cancer treatments using mathematical models can be very supportive in gaining more insight into dynamic processes responsible for cellular response to treatment, and predicting, evaluating and optimizing therapeutic effects of treatment. This review presents an overview of the current status of biological modeling for hyperthermia in combination with radiotherapy (thermoradiotherapy). Various distinct models have been proposed in the literature, with varying complexity; initially aiming to model the effect of hyperthermia alone, and later on to predict the effect of the combined thermoradiotherapy treatment. Most commonly used models are based on an extension of the linear-quadratic (LQ)-model enabling an easy translation to radiotherapy where the LQ model is widely used. Basic predictions of cell survival have further progressed toward 3 D equivalent dose predictions, i.e., the radiation dose that would be needed without hyperthermia to achieve the same biological effect as the combined thermoradiotherapy treatment. This approach, with the use of temperature-dependent model parameters, allows theoretical evaluation of the effectiveness of different treatment strategies in individual patients, as well as in patient cohorts. This review discusses the significant progress that has been made in biological modeling for hyperthermia combined with radiotherapy. In the future, when adequate temperature-dependent LQ-parameters will be available for a large number of tumor sites and normal tissues, biological modeling can be expected to be of great clinical importance to further optimize combined treatments, optimize clinical protocols and guide further clinical studies.

This work aims to establish some X-ray qualities recommended by the International Standard Organization (ISO) using the half-value layer (HVL) and Hp(10) dosimetry approaches. The HVL values of the following qualities N-60, N-80, N-100, N-150 and N-250 were determined using various attenuation layers. The obtained results were compared to those of reference X-ray beam qualities and a good agreement was found (difference less than 5% for all qualities). The GAMOS (Geant4-based Architecture for Medicine-Oriented Simulations) radiation transport Monte Carlo toolkit was employed to simulate the production of X-ray spectra. The characteristics HVLs, mean energy and the spectral resolution of simulated spectra have been calculated and turned out to be conform to the ISO reference ones (difference less than the limit allowed by ISO). Furthermore, the conversion coefficients from air kerma to personal dose equivalent for simulated and measured spectra were fairly similar (the maximum difference less than 4.2%).

Анализ радиационного воздействия при эксплуатации луноходов на Луне предполагает комплексное исследование радиационной стойкости (РС) бортовых устройств и аппаратуры, и радиационной безопасности экипажа. Вопросы РС лунохода были подробно освещены в работе (Власенков Е.В. и др., 2019). В настоящей статье рассматриваются уровни радиационного воздействия ионизирующего излучения космического пространства и радиоизотопных источников, расположенных на борту лунохода, на организм космонавта. Расчёты основаны на типовом сценарии строительных работ при создании лунной базы в соответствии с мировыми тенденциями освоения Луны и выполнены с применением трёхмерных моделей перспективных луноходов и разработанного программного комплекса, позволяющего учитывать вклад искусственных радиоизотопных источников и космического излучения. Результаты расчёта позволяют оценить уровень радиационной опасности для космонавтов и допустимое время их работы при непосредственной эксплуатации лунохода на поверхности Луны, An analysis of the radiation impact during the operation of lunar rovers on the Moon involves a comprehensive study of both the radiation hardness (RH) of on-board devices and equipment, and the radiation safety of the crew. The RH issues of the lunar rover were presented in detail in the work (Vlasenkov E.V. et al., 2019). This article discusses the exposure levels of ionizing radiation from space and radioisotope sources located on board the lunar rover on the astronaut's body. The calculations are based on a typical scenario of construction work during the creation of a lunar base in accordance with the global trends in the exploration of the Moon and are performed using three-dimensional models of promising moon rovers and a developed software package that allows taking into account the contribution of both artificial radioisotope sources and cosmic radiation. The results of the calculation make it possible to estimate the level of radiation hazard for astronauts and the permissible time of their work during the direct operation of the lunar rover on the surface of the Moon, Вестник НПО им. С.А. Лавочкина, Выпуск 2 (60) 2023, Pages 47-53

The intention of my diploma thesis was estimate the effective doses from different examinations in the area of the nuclear medicine and radiodiagnosis and find out what numbers are of the examinations in the Czech republic. In the theoretical part I worked with the professional literature, the applicable legal regulations and the internet links. The diploma thesis on the topic "Estimation of average doses of the population of the Czech republic from medical sources" is partition to the two parts. The introductory part of the theoretical work is dedicated to the importance of medical radiation within radiological methods and to the brief description the whole thesis. In the other part od the thesis are summarized the informations about the ionizing radiation - about his history, species, sources, interactions with the environment and biological effects on the organism. In the other part of the thesis which is devoted to radiation protection is listed the basic czech legislation which relates on the given topic. Further are in this thesis within the radiation protection listed her objectives, conception, principles, radiation protection methods, radiation monitoring and basic monitored quantities which are important in terms of the radiation protection. In the last part of the theoretical thesis is listed the medical radiation and his possibilities of use in the medical. In this thesis were to established three objectives. The first objective was to estimate the average effective doses in various examinations in the nuclear medicine and the radiodiagnosis. For selected examinations was calculated the average effective dose for patients who underwent the selected examination in January 2022. In the framework of nuclear medicine, it was an skeletal scintigraphy (96 patients), myocardial perfusion scintigraphy (51 patients), perfusion and ventilation lung scintigraphy (166 patients) and dynamic renal scintigraphy (12 patients). The results of these examinations were compared with data listed in UNSCEAR Report 2020/2021. In the famework of the radiodiagnosis, it was an CT brain natively (226 patients), abdominal CT natively (91 patients), CT chest native (33 patients) and CT of the lumbrar spine natively (46 patients). The results of these examinations were compared with data listed in UNSCEAR Report 2020/2021 and the results listed in the document "Medical radiation assessment" released by the SÚJB in the year 2021. The second objective was to find out how are numbers of examinations mentioned above in Czech republic. For this purpose I was provided with data from ÚZIS. Within this objective were estimated the collective effective doses. The third objective was estimated the relative probability of emergence of stochastic effects (the cancer). For this purpose was used the program named X-ray risk.

To estimate the mean effective dose per procedure with multiple dosimetry, to calculate the annual effective dose to personnel working in neuroendovascular procedures and compared with methods reported in the literature and with national and international limits. The radiation dose to personnel was monitored in 20 procedures classified as diagnostic or therapeutic. During each procedure, the equivalent dose to eyes, thyroid, under and over the lead apron at chest level, hands, gonads and knees was measured with lithium fluoride thermoluminescent dosimeter chips (TLD-100). Estimations of the annual effective dose from different methods found in literature that use one or two dosimeters and from this work were compared. Also, a comparison was made with the safety limits recommended in national and international regulations. Radiation exposure to eyes, thyroid, gonads and knees is relevant to the effective dose, and therefore to the annual effective dose estimations. Personnel position is important, as the performing physician, who is closer to the patient, received the highest dose measured. In particular, this was observed in the equivalent dose received over the apron. However, the equivalent dose to the right eye was higher for neuroanaesthesiologists than for performing physicians due to their position relative to the patient. In general, effective doses estimated using one- and two-dosimeter methods found in the literature were, respectively, lower and higher than those obtained with the ten-dosimeter method in this work. The annual effective doses to personnel estimated with the multiple dosimetry algorithm ranged from 1.3 to 1.5 mSv y−1 and are within the national and international limits.

In this paper, the results of indoor radon levels in the spas of Bosnia and Herzegovina, which became known as health institutions, are presented. With the method of solid state nuclear track detectors (SSNTD) type CR-39 the measurements of radon activity concentration in the air in spas of Bosnia and Herzegovina were performed. The results of measurements have shown that the values of radon activity concentrations at the investigated spa locations were in the range 6.5–168.4 Bqm−3. The estimated annual effective dose was in the range 0.04–0.97 mSvy−1 and 0.40–10.20 µSvy−1 for workers and patients, respectively. For all investigated spas excess lifetime cancer risk (ELCR) and dose equivalent were estimated.

An evaluation of cancer risk based on organ-absorbed dose is underway for the Japanese Epidemiological Study on Low-Dose Radiation Effects (J-EPISODE), which has analyzed health effects in association with radiation exposure evaluated with the personal dose equivalent Hp(10). Although the concept of effective dose and its operational definition of Hp(10) are widely used for radiological protection purposes, effective dose is not recommended for epidemiological evaluation. Organ-absorbed dose was instead adopted for the IARC 15-Country Collaborative study (15-Country study), the International Nuclear Workers Study (INWORKS), the Mayak worker study, and the Life Span Study (LSS) of atomic bomb survivors. The reconstruction method in J-EPISODE followed in principle the approach adopted in the 15-Country Study. As part of the approach of J-EPISODE, a conversion factor from photon dosimeter reading to air kerma was developed using dosimeter response data, which were measured by the experiment using an anthropomorphic phantom, and it was confirmed that the 15-Country study’s assumption of photon energy and geometry distribution in a work environment applied to Japanese nuclear workers. This article focuses on a method for reconstructing the conversion factor from photon dosimeter reading to organ-absorbed photon dose for a Japanese nuclear worker cohort. The model for estimating the conversion factor was defined under the assumption of a lognormal distribution from three concerned bias factors: (1) a dosimeter reading per air kerma, i.e., dosimeter response; (2) an organ-absorbed dose per air kerma; and (3) a factor relating to the differences in dose concepts and calibration practices between the roentgen dosimeter era and the present. Dosimeter response data were cited from the companion paper. Data on organ-absorbed photon dose per air kerma were estimated using a voxel phantom with the average Japanese adult male height and weight. The bias factor for the recorded dose in the roentgen era was defined, considering the backscatter radiation from the human body. The estimated values of organ-absorbed photon dose per air kerma were almost the same as those in ICRP Publication 116, revealing that the effect of differences in body size was almost negligible. The conversion factors from dosimeter reading to organ-absorbed dose were estimated by period (the roentgen era or from then), nuclear facility type (nuclear power plant or other), dosimeter type, and tissue or organ. The estimated conversion factors ranged from 0.7 to 0.9 (Gy Sv−1). The estimated cumulative organ-absorbed photon dose for the participants of J-EPISODE demonstrated that organ-absorbed dose values were approximately 0.8 times the recorded doses if neglecting dose-unit differences. J-EPISODE reconstructed an organ-absorbed dose conversion factor and will evaluate the risk of cancer mortality and morbidity using the organ-absorbed dose in the future.

Cone-beam CT (CBCT) applications possess potential for dose reduction in musculoskeletal imaging. This study evaluates the ultra-high-resolution CBCT prototype of a twin robotic X-ray system in wrist examinations compared to high-resolution multidetector CT (MDCT).Sixteen wrists of body donors were examined with the CBCT scan mode and a 384 slice MDCT system. Radiation-equivalent low-dose (CTDISubjective image quality in CBCT was superior to dose equivalent MDCT with p ≤ 0.03 for full-dose and p0.001 for low-dose scans, respectively. Median Likert values were 7/7 (reader 1 / reader 2) in full-dose CBCT, 6/6 in full-dose MDCT, 5/6 in low-dose CBCT and 3/3 in low-dose MDCT. Intraclass correlation coefficient was 0.936 (95% confidence interval, 0.897-0.961; p0.001), indicating excellent reliability. Objective analysis displayed smaller fractions of "indecisive" pixels with intermediate signal intensity for full-dose CBCT (0.57 [interquartile range 0.13]) compared to full-dose MDCT (0.68 [0.21]), low-dose CBCT (0.72 [0.19]), and low-dose MDCT (0.80 [0.15]) studies. No significant difference was observed between low-dose CBCT and full-dose MDCT.The new CBCT prototype provides superior image quality for trabecula and bone marrow in cadaveric wrist studies and enables dose reduction up to 75% compared to high-resolution MDCT.

Breakthrough whole body energy-specific photoneutron (PN) dosimetry was made in/out-of-field in polyethylene phantom organ surface/depths remote from isocenter of 10 × 10 cm2 field prostate cancer therapy in 18 MV X-rays Varian Clinac 2100C medical linear accelerator for PN tissue-specific second primary cancer (PN-SPC) risk estimation. A novel miniature neutron dosimeter/spectrometer with polycarbonate/10B/cadmium inserts was invented and applied. Each dosimeter determines seven tissue-specific dose equivalent (mSv)/Gy X-ray dose at each measurement point providing seven major energy-specific responses for beam thermal, albedo thermal, total thermal, total epithermal, total fast, sum of totals (thermal + epithermal) and sum of totals (thermal + epithermal + fast) PNs dose equivalents. The neutron dosimeter is simple, efficient, and unique with high spatial resolution and provides matrix of energy-specific PN dose equivalent (mSv)/Gy X-ray dose on surface and organ depths for tissue-specific PN-SPC risk estimation. The dosimeter also performs like a “miniature neutron spectrometer” and is unique for other applications in health physics in particular individual neutron dosimetry, medical physics, space flights, science and technology.

Background: Crookes tube is utilized in junior high and high schools in Japan to study the character of electrons and current, and not for radiological education. There is no official guideline or regulation for these radiation source to the public. Therefore, most teachers have no information about the leakage of X-rays from Crookes tube. The peak energy of X-rays is approximately 20 keV, and it is impossible to measure using conventional survey meters.Materials and Methods: Each leakage dose of low energy X-rays from 38 Crookes tube in the education field, such as junior and senior high schools in Japan, was explored by the teachers in the school using radio-photoluminescence (RPL) dosimeters. Before and after the measurements, the dosimeters were sent by postal mails.Results and Discussion: At the exploration in this study, it was estimated that the 70 μm dose equivalent, Hp(0.07) of X-rays from 31 Crookes tubes were smaller than 100 μSv in 10 minutes, at the distance of 1 m, where the Crookes tube was usually observed. However, the highest dose was estimated as 0.69 mSv by an equipment with the full power. Furthermore, one Crookes tube exhibited 0.62 mSv with minimum output power of the induction coil. This relatively large dose was reduced by the shorter distance of discharge electrodes of the induction coil.Conclusion: The leakage dose of low energy X-rays from 38 Crookes tube was explored using RPL dosimeters. It was estimated that the Hp(0.07) of X-rays from 31 Crookes tubes were smaller than 100 μSv in 10 minutes at the distance of 1 m, while some equipment radiated a higher dose. With this study, the provisional guideline for the safety operation of Crookes tube is established.

In the present work, radium (226Ra), thorium (232Th), potassium (40 K), and cesium (137Cs) (Bq/kg) was measured for 24 soil samples of some districts of Al-Doura city in Baghdad governorate. The gamma spectrometry method with NaI (Tl) detector was used for radiometric measurements. The average values of specific activity for 226Ra, 232Th, 40K and 137Cs in soil samples were 38.03, 42.48, 16.34 and 2.76 Bq/kg, respectively. The radiation indicators were measured and the average values recorded were 100 Bq/kg, 44.6 nGy/h, 0.27 Bq/kg, 0.373 Bq/kg, 0.219 mSv/y, 0.055 mSv/y and 0.689 Bq/kg for the parameters of radium equivalent activity (Raeq), the absorbed dose rate (D), the external hazard index (Hex), the internal risk index (Hin), and the annual effective equivalent dose for the indoor (In Eff.), outdoor annual effective dose equivalent (Out Eff.) and representative gamma index (Iγr), respectively. All the health hazard indices were well below their recommended limits, except in one soil sampling site (AL-Eskan site) which were found to be 0.495 Hex and 0.668 Hin.

Background Re-irradiation (reRT) is a promising technique for patients with localized recurrence in a previously irradiated area but presents major challenges. These include how to deal with anatomical change between two courses of radiotherapy and integration of radiobiology when summating original and re-irradiation doses. The Support Tool for Re-Irradiation Decisions guided by Radiobiology (STRIDeR) project aims to develop a software tool for use in a commercial treatment planning system to facilitate more informed reRT by accounting for anatomical changes and incorporating radiobiology. We evaluated three approaches to dose summation, incorporating anatomical change and radiobiology to differing extents. Methods In a cohort of 21 patients who previously received pelvic re-irradiation the following dose summation strategies were compared: (1) Rigid registration (RIR) and physical dose summation, to reflect the current clinical approach, (2) RIR and radiobiological dose summation in equivalent dose in 2 Gy fractions (EQD2), and (3) Patient-specific deformable image registration (DIR) with EQD2 dose summation. Results RIR and physical dose summation (Strategy 1) resulted in high cumulative organ at risk (OAR) doses being 'missed' in 14% of cases, which were highlighted by EQD2 dose summation (Strategy 2). DIR (with EQD2 dose summation; Strategy 3) resulted in improved OAR overlap and distance to agreement metrics compared to RIR (with EQD2 dose summation; Strategy 2) and was consistently preferred in terms of clinical utility. DIR was considered to have a clinically important impact on dose summation in 38% of cases. Conclusion Re-irradiation cases require individualized assessment when considering dose summation with the previous treatment plan. Fractionation correction is necessary to meaningfully assess cumulative doses and reduce the risk of unintentional OAR overdose. DIR can add clinically relevant information in selected cases, especially for significant anatomical change. Robust solutions for cumulative dose assessment offer the potential for future improved understanding of cumulative OAR tolerances.

The International Commission on Radiation Units and Measurements (ICRU) Report Number 95 (2020 Operational quantities for external radiation exposureICRU Rep. 95 J. ICRU20) recommends new definitions ffor operational quantities as estimators of the International Commission on Radiological Protection radiation protection quantities. As part of this report, dose coefficients for neutron fluences are included for energies from 10-9-50 MeV. For lens of the eye dosimetry, several changes in the ICRU recommended quantities are of particular interest. First, an updated eye model is used that includes segmentation of the sensitive lens region. In addition, the use of absorbed dose instead of dose equivalent has been selected as the appropriate operational quantity since deterministic (i.e. non-stochastic) effects are of primary importance for the lens of the eye. The ICRU report also addresses computational parameters, such as absorbed dose tally volumes, depths, source areas and source rotational angles. In this work, neutron dose coefficients calculated for the lens of the eye in support of the ICRU report are presented. Dose coefficients for mono-energetic neutrons and reference neutron spectra are presented. The source is a parallel beam, and the mono-energetic dose coefficients are provided for rotational angles with respect to the front face of the head ranging from 0°-90°. In addition, monoenergetic dose coefficients for the parallel beam incident on the back of the head (180°) and for a rotational source geometry where the head is irradiated from all angles are reported. For all scenarios, absorbed doses to the complete lens and the sensitive volume of each eye were calculated. Eye lens absorbed dose coefficients,Dp,slab(3,0)/Φ, were also calculated in an ICRU tissue slab phantom at a depth of 3 mm for a parallel beam irradiating the slab perpendicular to the front face, and these results are compared to the values determined using the eye phantom.

The objective of the present study was to evaluate the intensity and spatial distribution of the scattered radiation caused by the use of hand-held x-ray equipment in the zone occupied by the operator, using the Monte Carlo simulation for radiographic views of the upper and lower incisor teeth, and the consequent evaluation of the equivalent dose in the lens. In order to carry out this evaluation, the geometry of a typical dental facility with plaster walls containing the scattering object was used for the computational scenario implemented for the Monte Carlo method simulation. The PENELOPE code for Monte Carlo simulation of electron and photon transport was used with the radiation beam represented by a 60 kV spectrum, 1.5 mm Al and tungsten target. The simulations were carried out with typical parameters for workload and the number of radiographs/week. The results showed that the exposure levels varied significantly according to the angle of the x-ray beam and with the distance to the scattering object. It is concluded that the incorporation of hand-held equipment in dental radiology must be accompanied by the surveillance of occupational exposure levels and a review of the training structure of professionals in dental radiology regarding aspects of radiological protection and the particularities of using this type of equipment.

The Gamma-ray spectrometry (spectra line Gp) and a high-purity germanium (HPGe) detector were used to determine the activity concentrations of 226Ra, 232Th, and 40K in fertilizer samples. 226Ra, 232Th, and 40K activity concentrations in fertilizers and phosphate raw. In this study the gamma index(I), Radium equivalent dose(Raeq),dose rate(DR),external hazard index(Hex) internal hazard index(Hin), annual effective dose outdoor(AEDout) and annual effective dose indoor(AEDin)were found. This study could serve as a starting point for figuring out how fertilizer radiation affects human health.

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.

Intracavitary gynecologic brachytherapy in the form of tandem-based brachytherapy and vaginal cylinder-based brachytherapy represents a fundamental component of the treatment of women with cervical or uterine cancer due to the ability to deliver a therapeutic dose of radiation with sharp dose falloff. This results in highly effective treatment in terms of oncologic outcomes with an overall favorable toxicity profile. Still, complications and side effects of brachytherapy do exist. While advances in brachytherapy techniques have led to a significant decrease in the rates of toxicity, a thorough understanding of the potential complications is crucial to ensuring optimal outcomes for women with gynecologic cancer undergoing brachytherapy. Use of equivalent dose at 2 Gy per fraction (EQD2) models has allowed incorporation of external beam radiotherapy dose to the brachytherapy dose leading to development of consolidated dose constraints for organs-at-risk in the modern era. This manuscript offers a comprehensive review of potential complications associated with intracavitary brachytherapy for gynecologic cancer including predictive factors, mitigation tactics, and management strategies.

Introduction Occupational exposure to ionizing radiation for people working with an X-ray treatment unit is one of the highest in medicine. The epidemiological data analyzed by the International Commission on Radiological Protection (ICRP) indicate that the dose threshold for tissues located in the eye lens is or may be lower than previously thought. The new ICRP recommendations reduce the currently used threshold 7.5 times to the limit of 20 mSv per year. Aim To carry out measurements of equivalent doses for the lenses and scalps of cardiology interventional staff to determine the actual exposure. Material and methods Personnel performing interventional cardiology procedures participated in the measurements. The measurements were performed using thermoluminescence dosimetry in two measurement periods. The operational quantities used in individual dosimetry were determined (dose equivalent for the scalp, dose equivalent for the eye lens). In both measurement periods, 69 operators and 12 nurses took part. Results The maximum value of eye doses for cardiologists was 18.80 mSv per year, with a mean of 9.83 ±6.47 mSv/year (for all cases), 5.70 ±4.26 mSv/year (with safety glasses/headgear), 13.14 ±6.28 mSv/year (without safety glasses/headgear), and 6.28 ±1.76 mSv per year for the nurses. The values of brain doses fluctuate around 1 mSv per quarter. Conclusions Dose equivalents for the lenses of the eyes obtained by cardiologists may be close to or exceed the current dose limits.

In this study, a radiation alert meter was used to measure background ionizing radiation levels in four hospitals in Makurdi Metropolis, Benue State, North Central, Nigeria. This aimed to determine the radiological health implications of the measured background ionizing radiation study area's populace. The background ionizing radiation exposure rate (indoor and outdoor) measured ranged from 0.0014 to 0.0019 mRhr-1 with average value 0.0017 mRhr-1, 0.0015 to 0.0024 mRhr-1 with average value 0.0019 mRhr-1, 0.0013 to 0.0025 mRhr-1 with average value 0.0018 mRhr-1 and 0.0012 to 0.0024 mRhr-1 with average value 0.0018 mRhr-1 for the selected hospitals A, B, C and D, respectively. The study showed that the mean equivalent dose rate levels are within the international commission on radiological protection's standard permissible limits. The mean annual effective dose equivalent (indoor and outdoor) for all the selected hospitals is within the recommended permissible limits of 1.00 mSvy-1 for the general public. In the selected hospitals A, B, C, and D, the estimated Dorgan values for the lungs, ovaries, bone marrow, testes, kidney, liver, and whole-body due to radiation exposure and inhalation are below tolerable international limits of 1.0 mSv yearly. Hence the selected hospitals are radiologically safe.

The standardised growth curves (SGCs) can compensate for the drawbacks of the single-aliquot regenerative-dose (SAR) procedure, such as low utilization of time and instrument in the optically stimulated luminescence (OSL) dating. In this study, 12 sedimentary samples of 6 lakes from the Mongolian Plateau were selected and 90–125 μm coarse-grains quartz was extracted to establish SGCs. The results show that the OSL signals are mainly composed of a fast component, which is applicable for SAR procedure. The difference in the shape of the dose response curves (DRCs) limits the application of the standardised growth curve (SGC) for which the growth curves among the aliquots corrected by the test dose are scattered. The equivalent dose (De) estimated by the global standardised growth curve (gSGC) by the regenerative normalization (re-normalization) method is more consistent with the full SAR procedure, so the gSGC method is suitable for determining the De values on the regional scale of Mongolian Plateau. For different lacustrine sedimentary samples, the De values estimated by full SAR procedure and gSGC method are consistent for the doses of up to ~280 Gy. The discrepancy of growth curves may result from the sensibility changes of inter-cycle in SAR measurement and the recuperation, also we do not exclude the influence of feldspar inclusions.

Dose escalation has been associated with improved biochemical control for prostate cancer. Focusing the high dose on the MRI-defined intraprostatic lesions (IL) could spare the surrounding organs at risk and hence allow further escalation. We compare treatment efficacy between state-of-the-art focally-boosted proton and photon-based radiotherapy, and investigate possible predictive guidelines regarding individualized treatment prescriptions.Ten prostate cancer patients with well-defined ILs were selected. Multiparametric MRI was used to delineate ILs, which were transferred to the planning CT via image registration. Pencil beam scanning proton therapy and volumetric modulated arc therapy treatment plans, were created for each patient. Each modality featured 6 plans: (1) moderately hypofractionated dose: 70 Gy to the prostate in 28 fractions, (2)-(6) plan 1 plus additional simultaneous-integrated-boost to ILs to 75.6, 81.2, 86.6, 98 and 112 Gy in 28 fractions. Equivalent dose to 2 Gy-per-fraction (EqD2) was used to calculate tumor control (TCP) and normal tissue complication probabilities (NTCP) for ILs and organs-at-risk.For both modalities, the maximum necessary dose to achieve TCP99% was 98 Gy for very high-risk ILs. For lower risk ILs lower doses were sufficient. NTCP was25% and 35% for protons and photons at the maximum dose escalation, respectively. For the cases and beam characteristics considered, proton therapy was dosimetrically superior when IL was4 cc or located2.5 mm from the rectum.This work demonstrated the potential role for proton therapy in the setting of prostate focal dose escalation. We propose that anatomical characteristic could be used as criteria to identify patients who would benefit from proton treatment.

BACKGROUND Standard lead aprons and vests do not adequately shield the most common breast cancer site, the upper outer quadrant (UOQ), from intraoperative radiation. The purpose of the present study was to determine if lead sleeves, wings, and/or axillary supplements decreased intraoperative radiation exposure of the UOQ of the breast. METHODS An anthropomorphic torso phantom (simulating the female surgeon) was placed adjacent to a standard operating room table. Dosimeters were placed bilaterally over the UOQ of the breast. Scatter radiation dose equivalent rates (mrem/hr) were measured during continuous fluoroscopy of a pelvic phantom (simulating the patient). Five protection configurations (no lead; lead vest; and vest with sleeves, wings, and axillary supplements), 2 surgeon positions (facing the table and perpendicular to the table), and 2 C-arm positions (anteroposterior and cross-table lateral projection) were tested. The t test was utilized with a Bonferroni correction for multiple t tests. RESULTS Lead sleeves and axillary supplements decreased intraoperative radiation exposure to the UOQ of the breast when compared with a well-fitted standard lead vest alone (p < 0.01) across all surgeon and C-arm positions. The addition of wings decreased radiation exposure to a lesser extent than sleeves or axillary supplements, and the difference when compared with the lead vest alone did not reach significance (p = 0.29). Breast radiation exposure in the C-arm cross-table lateral projection was highest across all testing. CONCLUSIONS The UOQ of the breast is not adequately protected by standard lead vests alone or vests with the addition of wings. Axillary supplements and sleeves improved protection of the breast. CLINICAL RELEVANCE Modifications of lead protective vests may improve intraoperative breast radiation protection.

This paper investigates the activity concentration of radionuclides (226Ra, 232Th, 40K and 137Cs) in the wheat grain samples using a high-purity germanium detector. Thirty-six wheat grain samples were collected from different locations of Koya City, Iraqi Kurdistan region. Average activity concentrations of 226Ra, 232Th and 40K in wheat grain are found to be 0.407 ± 0.097 Bq.kg-1 for 226Ra, 0.36 ± 0.14 Bq.kg-1 for 232Th and 109.25± 2.214 Bq.kg-1 for 40K, respectively. The measured activity concentrations for the radionuclides are compared with the reported data from other countries. In addition, the fallout radionuclide of 137Cs has no detection of in the wheat grain samples. The radium equivalent activity Raeq, internal and external hazard indices Hin and Hex, and annual gonadal dose equivalent are calculated for the measured samples. The total ingestion dose is 113.19 µSv.y-1, which is below the world average value of 290 µSv.y-1.

Purpose A 5 and 10 μm thin silicon on insulator (SOI) 3D mushroom microdosimeter was used to characterise both the in-field and out-of-field of a 62 MeV proton beam. Methods The SOI mushroom microdosimeter consisted of an array of cylindrical sensitive volumes (SVs), developed by the Centre for Medical Radiation Physics, University of Wollongong, was irradiated with 62 MeV protons at the CATANA (Centro di AdroTerapia Applicazioni Nucleari Avanzate) facility in Catania, Italy, a facility dedicated to the radiation treatment of ocular melanomas. Dose mean lineal energy, ( y D ¯ ), values were obtained at various depths in PMMA along a pristine and spread out Bragg peak (SOBP). The measured microdosimetric spectra at each position were then used as inputs into the modified Microdosimetric Kinetic Model (MKM) to derive the RBE for absorbed dose in a middle of the SOBP 2Gy (RBED ). Microdosimetric spectra were obtained with both the 5 and 10 μm 3D SOI microdosimeters, with a focus on the distal part of the BP. The in-field and out-of-field measurement configurations along the Bragg curve were modelled in Geant4 for comparison with experimental results. Lateral out-of-field measurements were performed to study secondary particles' contribution to normal tissue's dose, up to 12 mm from the edge of the beam field, and quality factor and dose equivalent results were obtained. Results Comparison between experimental and simulation results showed good agreement between one another for both the pristine and SOBP beams in terms of y D ¯ and RBED . Though a small discrepancy between experiment and simulation was seen at the entrance of the Bragg curve, where experimental results were slightly lower than Geant4. The dose equivalent value measured 12 mm from the edge of the target volume was 1.27 ± 0.15 mSv/Gy with a Q ¯ value of 2.52 ± 0.30, both of which agree within uncertainty with Geant4 simulation. Conclusions These results demonstrate that SOI microdosimeters are an effective tool to predict RBED in-field as well as dose equivalent monitoring out-of-field to provide insight to probability of second cancer generation.

Soil samples were collected at 30 sampling points distributed evenly in Guangyao Village, South China to determine the radioactivity level around a monazite tailings pond via gamma spectrometry with an HPGe detector. The result of mean radioactivity concentration ± standard deviation of radionuclides 226Ra, 232Th and 40K in the soil were 26.84 ± 4.36,8.87 ± 0.93 and 453.81 ± 99.95 Bq kg−1, respectively. Shapiro–Wilk normality test results show 226Ra and 232Th radioactivity concentrations consistent with normal distributions. The natural radioactivity level in the soil was evaluated by Radium equivalent activity (Raeq), Absorbed dose rate (Dr), Annual effective dose equivalent (AEDE), Gamma level index (Iγ), Annual gonadal dose equivalent (AGDE), Internal Hazard Index (Hin) and External hazard index (Hex). The radionuclides and radioactive hazard parameters were also statistically analyzed. A spatial distribution map of radionuclides was generated with a geographic information system and subjected to correlation analysis, principal component analysis and cluster analysis of radionuclides and radioactive hazard parameters. The results show that the radioactivity level in the soil of Guangyao Village is lower than the world average and recommended value, suggesting that it poses no significant threat to local residents. This work may provide baseline data for future soil radioactive environmental monitoring.

Objective To inspect personal dose as an interventional radiologist for 40 years, to assess the enforcement number of interventional radiology (IR), and to check for radiation cataract. Materials and methods I evaluated my own effective dose, an equivalent dose to the lens of the eye (EDL), and the number of IR procedures between March 2019 and June 1979. I examined the lens in June 2019 as a radiologist for 40 years. Results The accumulation dose was 0 mSv in 1979–88. During 1989–93, the right crystalline lens equivalence of the value dose was measured. During 1993–96, two badge items for the head, neck, and abdomen were present. Both were distributed, but attaching to the same part and reversing occurred frequently. The EDL of the recent 5 years has exceeded 100 mSv. No association with the number of IR procedures was recognized. Posterior subcapsular vacuoles (PSV) as the early changes of the radiation cataract were recognized as four on the left and one on the right. Conclusion It is important to get accustomed to film badge wearing, and the cancelation of making a mistake in the wearing part. Radiologists should check the PSV at a stage beyond a certain constant dose.

Measurement of terrestrial background ionizing radiation of blacksmith workshops of Gombe State, Nigeria was carried out using well-calibrated Geiger-Muller counter meters and a meter tape. The measured average exposure rate of two line-sections are 0.018±0.002 and 0.017±0.002 mRh-1. Estimated equivalent dose rates for the two line-sections are 1.50 and 1.45 mSvy-1. The average absorbed dose rates estimated in line-section one and line-section two are 154.94 and 149.97 nGyh-1 respectively. Annual effective dose equivalent (AEDE) of 0.48 mSvy-1 was obtained for outdoor exposure in line-section one while in line-section two, AEDE was 0.23 mSvy-1. The calculated mean excess lifetime cancer risk values for the blacksmith workshop sections are 0.83x 10-3 and 0.80 x 10-3. The obtained values for background ionizing radiation in the line-sections of blacksmith workshop were above the recommended standard limit by ICRP while the absorbed doses (D) were above the recommended value and AEDE calculated in two line-sections of blacksmithing workshops were within the safe values this implies that blacksmithing activities in these areas may not influence the doses received by public. The excess lifetime cancer risk (ELCR) estimated were higher than their world permissible values of 0.29 x 10-3 respectively. The calculated dose to organs showed that the testes have the highest organ dose of 0.153 mSvy-1while liver has the lowest organ dose of 0.086 mSvy-1. This result shows that exposure to

Radiation can have undesirable effects on the eye, including a gradual loss of vision. Unnecessary radiation can reach the eye lens during non-enhanced computed tomography (CT) scans of the brain. The International Commission on Radiological Protection states the threshold for acute and chronic eye lens exposure is 500 mGy and the equivalent dose limit for the eye lens for public exposure is 15 mSv per year. Therefore, we measured the direct radiation dose to the eye lens during head CT scans using NanoDots in 216 adults. The mean absorbed dose to both eyes was 33.62 mGy (standard deviation ±12.442). The averages for the other variables were: tube current-time product: 260 mAs; dose-length product: 708 mGy cm and CT dose index: 35.5 mGy. Our findings encourage further study of radiation exposure and modifications in CT imaging protocols.

Background: Euronext Paris Advanced Orthopedic Solutions (EOS) system is a new radiography system, capable of obtaining two-dimensional and three-dimensional images from bony structures in the body. Objective: The aim of this study is to estimate equivalent dose and the risk of exposure induced cancer death (REID) in different organs of body due to EOS imaging system. Material and Methods: In this experimental study, totally 120 patients were evaluated for various imaging techniques of lower limb, full spine and whole body. Equivalent dose and REID for colon, liver, lung, stomach, breast, bladder, ovary, blood cells (leukemia) and other organs were calculated using PCXMC software (version 2.0.1.2) based on Monte Carlo simulation of X-ray and human phantoms. The data on imaging technique, including age, sex, kVp, dose area product (DAP), mA, focal to detector distance were introduced as the input of PCXMC. Results: The maximum equivalent dose (mSv) due to EOS imaging system, was estimated for the bladder 0.240±0.066 for the full body technique and 0.240±0.093 for the lower limb technique, respectively, in both males and females. The maximum organ REID (incidence per million) due to EOS imaging system was estimated for lungs as 2.59±1.0 and 2.53±0.9, for the full body technique in both males and females, respectively. Conclusion: Generally, the equivalent dose and REID by EOS imaging system in different organs of body is low due to the low radiation dose received by the body in different techniques and views.

BACKGROUND: Pelvic lymph node (PLN) metastasis has been included in the FIGO staging, so there is a need to determine the dose contribution from brachytherapy to ascertain the total delivered dose to the pelvic lymph nodes in cervical cancer. The aim of the study was to calculate the equivalent dose in 2 Gy (EQD2) of the pelvic lymph nodes (PLNs) based on volume prescription using three applicators. Materials and methods: Forty-one patients who had undergone external beam radiotherapy followed by brachytherapy using tandem ovoids (TO), tandem ring (TR) and TO + free hand interstitial needles (TO + FH) applicators were taken for this study. 26 Gy in 4 fractions was prescribed to HRCTV. The external iliac node (ELN), internal iliac node (ILN) and obturator (OBT) were contoured and the median EQD2 of the lymph nodes was calculated. RESULTS: The median bilateral EQD2 values of ELN were 1.55 Gy (TR), 1.75 Gy (TO), 1.9 Gy (TO + FH), of ILN these were 2.57 Gy (TR), 3.27 Gy (TO), 3.04 Gy (TO + FH), and of OBT these were 3.69 Gy (TR), 4.46 Gy (TO), 4.69 Gy (TO + FH), respectively. The total median EQD2 values of TR, TO and TO + FH were 52.71 Gy, 53.03 Gy, and 53.88–62.73 Gy, respectively. CONCLUSION: Our study calculated the median EQD2 to the pelvic lymph nodes using three types of applicators in brachytherapy. This could serve as reference to decide on the EBRT boost dose while treating patients with enlarged pelvic lymph nodes.

We have developed physical and biological beam modeling for carbon scanning therapy at the Osaka Heavy Ion Therapy Center (Osaka HIMAK). Carbon beam scanning irradiation is based on continuous carbon beam scanning, which adopts hybrid energy changes using both accelerator energy changes and binary range shifters in the nozzles. The physical dose calculation is based on a triple Gaussian pencil‐beam algorithm, and we thus developed a beam modeling method using dose measurements and Monte Carlo simulation for the triple Gaussian. We exploited a biological model based on a conventional linear‐quadratic (LQ) model and the photon equivalent dose, without considering the dose dependency of the relative biological effectiveness (RBE), to fully comply with the carbon passive dose distribution using a ridge filter. We extended a passive ridge‐filter design method, in which carbon and helium LQ parameters are applied to carbon and fragment isotopes, respectively, to carbon scanning treatment. We then obtained radiation quality data, such as the linear energy transfer (LET) and LQ parameters, by Monte Carlo simulation. The physical dose was verified to agree with measurements to within ±2% for various patterns of volume irradiation. Furthermore, the RBE in the middle of a spread‐out Bragg peak (SOBP) reproduced that from passive dose distribution results to within ±1.5%. The developed carbon beam modeling and dose calculation program was successfully applied in clinical use at Osaka HIMAK.

Calculations of the neutron response for the most widely used neutron dosimeters at the Russian nuclear power plant (NPP) have been performed. It is shown that in some cases it is necessary to introduce a correction for the measured value of the ambient dose equivalent rate (AEDR). The experimentally tested values of the correction for measuring AEDR in the containment rooms of NPP with VVER-1200 are given.

Despite the low contribution of heavy ions to the total fluence in the space radiation environment, their radiobiological effect on the human body is extremely high. In this article, we investigated the radiation field which resulted from the interaction of galactic cosmic rays (GCRs), specifically some heavy ions and energies, typically encountered in space with a realistic multilayer sample of the International Space Station (ISS) Columbus module’s shielding wall. The quality factor, Q, and the normalized dose equivalent, H, derived from microdosimetric measurements for C, Ne, and Si ions behind different spacecraft wall configurations and materials are presented in this article. Particularly, carbon fiber, polyoxymethylene, and perspex with same areal density compared to currently used aluminum were investigated.

PURPOSE: We sought to investigate the tumor control probability (TCP) of vestibular schwannomas (VS) following single-fraction stereotactic radiosurgery (SRS) or hypofractionated SRS over 2–5 fractions (fSRS). MATERIALS AND METHODS: Studies (PubMed Indexed from 1993 – 2017) were eligible for data extraction if they contained dosimetric details of SRS/fSRS correlated with local tumor control. The rate of tumor control at 5 years (or at 3 years if 5-year data were not available) were collated. Poisson modeling estimated the TCP per equivalent dose in 2 Gy per fraction (EQD2) and in 1, 3, and 5 fractions. RESULTS: Data were extracted from 35 publications containing a total of 5162 patients. TCP modeling was limited by the absence of analyzable data of

Spinal cord tolerance data for stereotactic body radiation therapy (SBRT) were extracted from published reports, reviewed, and modelled. For de novo SBRT delivered in 1 to 5 fractions, the following spinal cord point maximum doses (Dmax) are estimated to be associated with a 1% to 5% risk of radiation myelopathy (RM): 12.4 to 14.0 Gy in 1 fraction, 17.0 Gy in 2 fractions, 20.3 Gy in 3 fractions, 23.0 Gy in 4 fractions, and 25.3 Gy in 5 fractions. For reirradiation SBRT delivered in 1 to 5 fractions, reported factors associated with a lower risk of RM include cumulative thecal sac equivalent dose in 2 Gy fractions with an alpha/beta of 2 (EQD22) Dmax ≤70 Gy; SBRT thecal sac EQD22 Dmax ≤25 Gy, thecal sac SBRT EQD22 Dmax to cumulative EQD22 Dmax ratio ≤0.5, and a minimum time interval to reirradiation of ≥5 months. Larger studies containing complete institutional cohorts with dosimetric data of patients treated with spine SBRT, with and without RM, are required to refine RM risk estimates.

Purpose Stereotactic body radiation therapy (SBRT) and stereotactic ablative body radiation therapy is being increasingly used for pancreatic cancer (PCa), particularly in patients with locally advanced and borderline resectable disease. A wide variety of dose fractionation schemes have been reported in the literature. This HyTEC review uses tumor control probability models to evaluate the comparative effectiveness of the various SBRT treatment regimens used in the treatment of patients with localized PCa. Methods and Materials A PubMed search was performed to review the published literature on the use of hypofractionated SBRT (usually in 1-5 fractions) for PCa in various clinical scenarios (eg, preoperative [neoadjuvant], borderline resectable, and locally advanced PCa). The linear quadratic model with α/β= 10 Gy was used to address differences in fractionation. Logistic tumor control probability models were generated using maximum likelihood parameter fitting. Results After converting to 3-fraction equivalent doses, the pooled reported data and associated models suggests that 1-year local control (LC) without surgery is ≈79% to 86% after the equivalent of 30 to 36 Gy in 3 fractions, showing a dose response in the range of 25 to 36 Gy, and decreasing to less than 70% 1-year LC at doses below 24 Gy in 3 fractions. The 33 Gy in 5 fraction regimen (Alliance A021501) corresponds to 28.2 Gy in 3 fractions, for which the HyTEC pooled model had 77% 1-year LC without surgery. Above an equivalent dose of 28 Gy in 3 fractions, with margin-negative resection the 1-year LC exceeded 90%. Conclusions Pooled analyses of reported tumor control probabilities for commonly used SBRT dose-fractionation schedules for PCa suggests a dose response. These findings should be viewed with caution given the challenges and limitations of this review. Additional data are needed to better understand the dose or fractionation-response of SBRT for PCa.

The purpose of this study was to evaluate the effect of dose rate to the rectum on late rectal complications in patients treated with computed tomography (CT)-based image-guided brachytherapy (IGBT) for cervical cancer. The subjects were 142 patients with cervical cancer who underwent Ir-192 high-dose-rate (HDR)-IGBT between March 2012 and January 2018. The dose rate to the rectum was calculated using in-house software. The minimum, mean and maximum effective dose rate (EDR) was calculated for voxels of the rectal volume covered by cumulative doses >D0.1cc, >D2cc, and > D5cc. The average EDR of three to four brachytherapy sessions was calculated (EDR for patients; EDRp). The total dose of the rectum was calculated as the biologically equivalent dose in 2-Gy fractions (EQD2). The associations between EDRp for D0.1cc, D2cc, and D5cc and the respective rectal EQD2 values with late rectal complications were then analyzed. The median follow-up period was 40 months. Patients with rectal complications of ≥Grade 1 received a significantly higher mean EDRp for D0.1cc–5cc and had a greater EQD2 for D0.1cc–5cc. Multivariate analysis was performed using the mean EDRp for D2cc, EQD2 for D2cc, heavy smoking and BMI. Of these four variables, mean EDRp for D2cc (HR = 3.38, p = 0.004) and EQD2 for D2cc (HR = 2.59, p = 0.045) emerged as independent predictors for late rectal complications. In conclusion, mean EDRp and EQD2 were associated with late rectal complications in patients treated with HDR CT-based IGBT for cervical cancer.

The article presents data on the radiation situation on the territories of the protected zones of peaceful nuclear explosions «Globus-2», «Agat» and «Rubin-1» based on the results of field studies in 2020. Peaceful nuclear explosions were conducted in the Arkhangelsk region for seismic exploration. The results of the radiation-hygienic state of protected zones and radiation safety in the territories adjacent to peaceful nuclear explosions are analyzed by the main indicators: the values of the ambient dose equivalent of gamma radiation, the identification of gamma-emitting radionuclides in situ by field gamma spectrometry, the specific activity of technogenic radionuclides in the soil and tritium in the water of reservoirs and drinking water sources. An assessment of the sanitary condition of the studied territories of protected zones of peaceful nuclear explosions is given. It was found that the levels of the ambient dose equivalent rate of the gamma radiation at all sites are at the level of fluctuations in the natural regional radiation background in the range of 0.08-0.20 microSv/h. On the territory of the protected zone of the peaceful nuclear explosion «Globus-2» were repeatedly identified areas of minor local soil contamination with 137Cs (the previous study was performed in 2011). Increased values of the ambient equivalent dose rate of gamma radiation (0.20 -0.22 μSv/h) and specific activity of 137Cs in two soil samples (154 and 160 Bq/kg, respectively) were found in these areas. The tritium content in the water of water supply sources does not exceed 5 Bq/kg. These values are typical for global levels of this radionuclide in water bodies. Remains of technological equipment were found on the territories of the protected zones of the peaceful nuclear explosions (especially in the protected zone of the explosion «Agat»), as well as rusty metal pipes and barrels, the remains of wooden structures, etc. Information signs installed on dilapidated concrete foundations at the mouths of combat wells of all surveyed peaceful nuclear explosions have subtle inscriptions. The presence of forest thickets in the places where the investigated peaceful nuclear explosions are conducted and their ignition during forest fires is a potential threat to the release of technogenic radionuclides during depressurization of the mouths of combat wells.

Conventional chest-radiography images are the most basic X-ray imaging system for diagnosing lung diseases. However, space-averaging increases due to the overlapping of anatomy structures as three-dimensional information are reduced in two-dimensions. A dual-energy X-ray imaging (DEI) technique for resolve space-averaging is used to increase the conspicuity of the lesion (i.e., lung nodule and calcification) by suppressing anatomical background noise. DEI techniques perform the weighted log-subtraction using the attenuation characteristics of the material for low- and high-kilovoltage-peak (kVp) X-rays. And the weighting factor is calculated to suppressing anatomical background. The objective of this research is to increase the lesion conspicuity in lung regions by optimizing DE technique parameters. DE technique has been applied to three phantoms mimicking the average, thick, and thicker adult chest thicknesses while maintaining the total incident dose equivalent to that used to obtain a single chest radiograph. Investigating DE technique parameters include the added filtration, the low- and high-kVp pair, and the dose allocation between low- and high-kVp setups at the total dose equal to or less than that of the conventional chest radiograph. And the DE image performances investigated through contrast-to-noise ratio, modulation-transfer function, noise-power spectrum, and detective quantum efficiency.

The new recommendation of the International Commission on Radiological Protection for occupational eye dose is an equivalent dose limit to the eye of 20 mSv year–1, averaged over a 5-year period. This recommendation is a drastic reduction from the previous limit of 150 mSv year–1. Hence, it is important to protect physicians’ eyes from X-ray radiation. Particularly in interventional radiology (IVR) procedures, many physicians use protective lead (Pb) glasses to reduce their occupational exposure. This study assessed the shielding effects of novel 0.07 mm Pb glasses. The novel glasses (XR-700) have Pb–acrylic lens molded in three dimensions. We studied the novel type of 0.07 mm Pb glasses over a period of seven consecutive months. The eye dose occupational radiation exposure of seven IVR physicians was evaluated during various procedures. All IVR physicians wore eye dosimeters (DOSIRIS™) close to the left side of the left eye. To calculate the shielding effects of the glasses, this same type of eye dosimeter was worn both inside and outside of the Pb lenses. The average shielding effect of the novel glasses across the seven physicians was 61.4%. Our results suggest an improved shielding effect for IVR physicians that use these glasses. No physician complained that the new glasses were uncomfortable; therefore comfort is not a problem. The lightweight glasses were acceptable to IVR physicians, who often must perform long procedures. Thus, the novel glasses are comfortable and reasonably protective. Based on the results of this study, we recommend that IVR physicians use these novel 0.07 mm Pb glasses to reduce their exposure.

Background Treatment adaptation based on tumour biomarker response during radiotherapy of prostate cancer, could be used for both escalation and de-escalation of radiation doses and volumes. To execute an adaptation involving extension of treatment volumes during radiation can however be restricted by the doses already delivered. The aim of this work was to develop a treatment planning method that addresses this challenge. Material and methods A volumetric-modulated-arc-therapy (VMAT) planning method with sequential plan-on-plan optimization was developed for a prospective phase II trial including 100 patients on salvage radiotherapy (SRT) for prostate cancer recurrence. A treatment adaptation was performed after five weeks of SRT based on prostate-specific antigen response during this phase of the treatment. This involved extension of treatment volumes for non-responders (n = 64) to include pelvic lymph nodes and boost to 68Gallium-Prostate-Specific-Membrane-Antigen-Positron-Emission-Tomography positive lesions. This method was evolved by introducing an EQD2 (equivalent dose in 2.0 Gy fractions) correction of the base plan for improved dose coverage. Results All dose-volume criteria for target coverage were met for the non-responders when based on physical dose. An EQD2 correction of the base plan for non-responders, implemented for the final 29 patients, led to a statistically significant improvement in dose coverage as compared to the 35 patients treated without EQD2 correction. Conclusions This is to our knowledge the only study presented on biomarker-guided sequential VMAT radiotherapy using a plan-on-plan technique in the pelvis. By using a biologically adapted technique an improved target coverage was achieved without compromising doses to organs at risk.

Human activities such as waste disposal tend to impact negatively on the environment. Some waste products are associated with elevated levels of natural radioactivity. It was therefore, the aim of the study to investigate the health risk associated with natural radioactivity from Okakarara municipal waste dumpsite. In this study, gamma spectrometric analysis was used to determine the activity concentrations of 226Ra, 232Th and 40K in 18 soil samples. From these activity concentrations, some radiological parameters were calculated. The average activity concentrations of 226Ra, 232Th and 40K in (Bq.kg-1) were 15.45±0.47, 18.00±0.55, and 215.73±4.29, respectively. The average Raeq value was 57.80±0.98 Bq.kg-1. In all the samples, Raeq values were found to be lower than the worldwide value of 370 Bq.kg-1. The absorbed dose rate was found to be 27.00±0.44 nGy.h-1, whereas an average value of 0.03 mSv.y-1 for AEDE is noted, which is less than 0.48 mSv, the worldwide average. The Annual Gonadal Dose Equivalent (AGDE) was 190.89 μSv.y-1, a value less than the world average of 298 μSv.y-1. The average values of the Representative Level Index (RLI) and the External Hazard Index (Hex) was found to be 0.43 and 0.16., respectively. These indices were less than unity. The average value of the excess lifetime cancer risk (ECLR) was 1.16 x 10-4. This value was lower than the internationally acceptable limit of 2.9 x 10-4. From these results it can be concluded that natural radioactivity from the wasteland area of Okakarara was not an issue of health concern.

Breast cancer patients undergoing radiation therapy can be treated using the 3D conformal or VMAT techniques. For both plans, the doses received by the target and the organs at risk are determined and compared with protocols recommended for the safety of the patients. CT simulations of 10 women with left breast cancer were used for a 3D conformal and VMAT treatment plans in the radiotherapy department of Ain Wazein Medical Village Hospital (AWMV) utilizing Monaco Treatment Planning system using Collapsed-cone and Monte Carlo algorithms respectively. The total prescribed dose to the PTV was 50 Gy in 25 fractions each 2 Gy. The dosimetric parameters obtained were mean, D95%, and homogeneity index for PTV; mean dose and max doses for the heart; the V20% for the left and the right lungs. All values of this retrospective study were analysed and compared to the normal tissue maximum dose tolerance. VMAT plans resulted in significantly better coverage for the target volume concepts as compared with 3D-CRT (D95: 97% vs. 82%, p-value = 0.002; Dmean 4953 cGy in 3D-CRT vs. 5093 cGy in VMAT, p-value = 0.01). The left lung (V20:28.44% with 3D-CRT vs. 21.93 with VMAT, p-value = 0.02). For the heart (Dmax = 4919 cGy in 3D-CRT vs. 4617 cGy in VMAT, p-value = 0.07). For the right lung (V20 was 0.12% in 3D-CRT vs. 0.52% in VMAT with p-value = 0.008). Even though the p-value was significant for the 3D conformal technique, the dose for both techniques was very low and non-significant to have a risk in the organ. The VMAT technique with correct target volume delineation allowed a significant dose escalation and an increase in Tumor Control Probability (TCP). VMAT resulted in an improved sparing of OARs as compared with 3D-CRT at equivalent dose levels.

A portable radiographic system capable of fluoroscopic imaging in the neonatal intensive care unit (NICU) potentially benefits critically ill neonates by eliminating the need to transport them to a fluoroscopy suite. To evaluate whether a portable bedside fluoroscopy system in the NICU can deliver comparable image quality at a similar dose rate to a standard system in a fluoroscopy suite. In phase A, 20 patients

Objectives To compare ultra-low-dose CT (ULD-CT) of the osseous pelvis with tin filtration to standard clinical CT (CT), and to assess the quality of computed virtual pelvic radiographs (VRs). Methods CT protocols were optimized in a phantom and three pelvic cadavers. Thirty prospectively included patients received both standard CT (automated tube voltage selection and current modulation) and tin-filtered ULD-CT of the pelvis (Sn140kV/50mAs). VRs of ULD-CT data were computed using an adapted cone beam–based projection algorithm and were compared to digital radiographs (DRs) of the pelvis. CT and DR dose parameters and quantitative and qualitative measures (1 = worst, 4 = best) were compared. CT and ULD-CT were assessed for osseous pathologies. Results Dose reduction of ULD-CT was 84% compared to CT, with a median effective dose of 0.38 mSv (quartile 1–3: 0.37–0.4 mSv) versus 2.31 mSv (1.82–3.58 mSv; p < .001), respectively. Mean dose of DR was 0.37 mSv (± 0.14 mSv). The median signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of bone were significantly higher for CT (64.3 and 21.5, respectively) compared to ULD-CT (50.4 and 18.8; p ≤ .01), while ULD-CT was significantly more dose efficient (figure of merit (FOM) 927.6) than CT (FOM 167.6; p < .001). Both CT and ULD-CT were of good image quality with excellent depiction of anatomy, with a median score of 4 (4–4) for both methods (p = .1). Agreement was perfect between both methods regarding the prevalence of assessed osseous pathologies (p > .99). VRs were successfully calculated and were equivalent to DRs. Conclusion Tin-filtered ULD-CT of the pelvis at a dose equivalent to standard radiographs is adequate for assessing bone anatomy and osseous pathologies and had a markedly superior dose efficiency than standard CT. Key Points • Ultra-low-dose pelvic CT with tin filtration (0.38 mSv) can be performed at a dose of digital radiographs (0.37 mSv), with a dose reduction of 84% compared to standard CT (2.31 mSv). • Tin-filtered ultra-low-dose CT had lower SNR and CNR and higher image noise than standard CT, but showed clear depiction of anatomy and accurate detection of osseous pathologies. • Virtual pelvic radiographs were successfully calculated from ultra-low-dose CT data and were equivalent to digital radiographs.