High Radiation Risk Research Articles

Assessment of the radiation risk to health caused by the intake of Cs-137 and Sr-90 radionuclides from food in the able-bodied population of the Samara region

Monitoring of the content of technogenic radionuclides (Cs-137 and Sr-90) in foods is one of the key areas in ensuring radiation safety of the population, taking into account the current radiation situation. The greatest risk to health is food produced or imported from the territories that have been subjected to man-made radiation accidents. The purpose of the research was to assess the radiation risk caused by oral intake of radionuclides based on the study of the actual nutrition of the adult population and contamination of food with Cs-137 and Sr-90 radionuclides. Material and methods. The specific activity of Cs-137 and Sr-90 radionuclides (median and 90 percentile) was assessed by gamma spectrometric method in 1235 samples of food produced in the Samara region and imported from outside. Data on the actual nutrition of 894 respondents aged 18 to 68 years (in the autumn-winter period) were obtained by the 24-hour dietary recall using the automated software package Nutri-prof (version 2.9). Based on the data obtained, effective annual doses of internal radiation were calculated, information was obtained on the risks of malignant neoplasms, including in the long-term period under various scenarios of internal radiation. Results. Radiometric studies of food samples did not reveal deviations from hygienic standards. The highest median values of Cs-137 specific activity were observed in samples of forest mushrooms (1.23 Bq/kg), wild berries (0.97 Bq/kg), fish and fish products (0.96 Bq/kg). The highest median values of Sr-90 specific activity were also observed in samples of forest mushrooms (3.86 Bq/kg), fish and fish products (2.71 Bq/kg). The radiation risk under various scenarios of Cs-137 intake was regarded as «negligible», while the risk was regarded as «small» when consuming food contaminated with Sr-90. The number of additional cases of malignant neoplasms at the admission of Cs-137 in the median values of specific activity is 0.38 per year, at maximum values - 0.57 per year, at the admission of Sr-90 - 2.04 per year and 3.30 cases per year, respectively. Conclusion. The implementation of radiation monitoring of food, especially those imported from areas of high radiation risk, is a necessary condition for ensuring radiation safety of the population. It is also necessary to take into account the stochastic effect of the influence of small doses of internal exposure on the organism when consuming food, which make a significant contribution to the formation of the dose of internal radiation.

Initial Study of A-mode Ultrasound Spectroscopy Through Mechanical Wave Scattering Phenomenon for Measuring 3D-printed Bone Model Density

In Indonesia, the prevalence of osteoporosis is high. Given the economic burden it may impose on the population, this condition must be taken seriously. Dual-energy X-ray absorptiometry is the gold standard for diagnosing osteoporosis (DEXA). However, due to its high cost, non-portability, and radiation risk, DEXA cannot be applied to large populations. An alternative method for evaluating bone quality is ultrasound. It is more affordable, portable, and has no radiation risk. In this preliminary study, an A-mode ultrasound spectroscopy prototype for assessing the density of a 3D-printed bone model is designed. A single-element transducer (Transmit-Tx/Receive-Rx), a reconfigurable and modular FPGA-based ultrasound beamformer system, and a Raspberry Pi 3 are the system's control units. The raw radio frequency (RF) signal is acquired from three variations of density of the 3D-printed bone model, i.e., 100%, 60%, and 40%, to represent normal bone, osteopenia, and osteoporosis. The designed prototype can adequately characterize the mechanical wave scattering pattern of the 3D-printed bone model indicated by the increased tendency in the maximum amplitude when the density of the bone model is increasing. The tendency is the opposite for delay time and Power Spectral Density (PSD). These three signal parameters are potential candidate parameters to represent bone density. For future work, the selected candidate parameters can later be used as reference values while adding a significant data so that a machine learning method can be employed to extract representative features of bone density level, i.e., normal bone, osteopenia, and osteoporosis.

To Mars and Beyond: Engineering Life as a Moral Duty

To Mars and Beyond: Engineering Life as a Moral Duty

Features of the Course of Various types of Stroke in Patients Exposed to Low-dose Radiation

BACKGROUND: There is limited number of studies about peculiarities of cardiovascular diseases in population of different region by the zone of radiation exposure risk. AIM: The aim of the study was to study the effect of radiation factor on the pathogenesis of stroke. MATERIALS AND METHODS: To study the in influence of radiation factor on pathogenesis of stroke, 358 stroke patients were distributed based on the place of their residence into corresponding zones of radiation risk: 53 patients lived in zone of extremely high radiation level (488–100 cSV, zone I): 75 - from the zone of maximal radiation exposure (35–100 cSV, zone II), 158 - from zone with high radiation exposure (35–7 cSV, zone III), and 72 patients were the residents of minimal radiation risk (1–7 cSV, zone IV). RESULTS: The study of coagulation hemostasis had revealed the significant increase of fibrinogen level in patients from zone I: 4.7 ± 0.14% versus 3.2 ± 0.11%, in patients living in minimal radiation risk zone (p < 0.01). The patients from extremely high radiation risk had significant decrease in fibrinolysis time in comparison to patients from zone IV (p < 0.05). The primary APS was diagnosed in 24 (6.7%) patients in total group of stroke patients (11 males and 13 females), from which 21 patients with ischemic stroke and 3 with hemorrhagic stroke. Leiden Va defect was found significantly more often in patients lived in high radiation risk zone (9.4%), in 13.5% stroke patients from zone II, in 13.2% patients lived in zone I, in comparison to 6.9% patients lived in zone IV. The patients from zone I had significantly higher level of plasma homocysteine in comparison to patients from other zones, (p < 0.01). Furthermore, the significantly higher levels of plasma homocysteine were found in the group with maximal and high radiation exposure, in comparison to the group of patients from minimal risk zone (p < 0.05). CONCLUSIONS: We can see the presence of indirect evidences of modifying influence of radiation factor on pathogenic mechanisms of stroke.

Оценка радиационной безопасности населения загрязнённых вследствие аварии на Чернобыльской АЭС районов Брянской области на основе расчёта радиационных рисков с учётом их неопределённостей

The current recommendations of the International Commission on Radiological Protection (ICRP) are based on the classification of exposure situations as: planned, emergency and existing exposure situations. In planned situations, annual risk limits are set to limit human exposure. However, in emergency exposure situations or in existing exposure situations, permanent (annual) source control is not always possible, so the radiation protection strategy by monitoring the individual annual risk limit cannot always be practically implemented either. The purpose of this work is to assess the radiation safety of the population currently residing (at the beginning of 2022) in six districts of the Bryansk region: contaminated with radionuclides as a result of the Chernobyl accident: in Gordeevsky, Zlynkovsky, Klimovsky, Klintsovsky, Krasnogorsky and Novozybkovsky districts. Assessment of the current state of radiation safety of the population is based on calculations of the radiation detriment from chronic exposure due to living in contaminated areas, considering uncertainties of the reconstructed exposure doses and the parameters of mathematical risk models for the population. Radiation damage is calculated according to the modern ICRP methodology. Based on the general principle of conservative assessment of safety, the calculated upper 95% confidence limits (95% CL) of radiation detriment are compared with the corresponding lifetime radiation detriment limit, 3.510-3, determined by the Russian radiation safety standards (NRB-99/2009) under normal exposure conditions for the nominal period 70 years of life for the public. The radiation safety of the population of the Klimovsky district corresponds to the normal conditions of exposure from technogenic sources of ionizing radiation. Among the population of the remaining five contaminated districts of the Bryansk region, critical groups have been identified, the radiation detriment for which exceeds the limit 3.510-3 for normal conditions of public exposure in planned situations. The results of this work can be used in the preparation of recommendations for health authorities to improve medical monitoring of exposed citizens living in territories contaminated with radionuclides, as well as in the development of regulatory documents for the provision of targeted medical care to people from high radiation risk groups with the use of personalized medicine methods.

The possible impact of passive smoke exposure on radiation-related risk estimates for lung cancer among women: the life span study of atomic bomb survivors

Purpose Analyses of the Life Span Study cohort of atomic bomb survivors have shown a statistically significant sex difference in the excess risk of incident lung cancer due to radiation exposure, with the radiation-related excess relative risk per gray (ERR/Gy) for women approximately 4 times that for men, after accounting for active smoking. We sought to determine the extent to which this risk difference could be explained by adjustment for passive smoke exposure, which is a known risk factor for lung cancer that was not measured among Life Span Study participants, and which could be particularly influential among female never-smokers. Materials and methods The Life Span Study includes survivors of the atomic bombings of Hiroshima and Nagasaki and city residents who were not in either city at the time of the bombings, matched to survivors on city, sex, and age. First primary lung cancers were identified from population-based cancer registries between 1958 and 2009. Data on active smoking were obtained from mailed surveys and in-person questionnaires (1965–1991). We calculated passive smoke exposure for female never-smokers by attributing smoking pack-years at various intensities (5–50%) based on smoking patterns among men, stratified by city, birth year, radiation dose, and lung cancer status. Poisson regression models with additive and multiplicative interactions between radiation dose and smoking were used to estimate sex-specific radiation-related excess relative risks for lung cancer. Results During the study period, 2,446 first primary lung cancers were identified among 105,444 study participants. On average, male smokers started smoking 19.5 cigarettes per day at 21.5 years old. Partially attributing male smoking patterns to female never-smokers—to approximate passive smoke exposure—yielded lower radiation-related ERR/Gy estimates for women under a multiplicative radiation-smoking interaction model, leading to a lower female-to-male ratio of ERR/Gy estimates; however, this difference was evident only at very high passive smoke intensities. Under an additive radiation-smoking interaction model, the results were unchanged. Conclusions Our results are consistent with the possibility that failure to account for passive smoke might contribute, in small part, to the higher radiation risk estimates for lung cancer among women compared to men in the Life Span Study.

Screening for Sarcopenia (Physical Frailty) in the COVID-19 Era.

Although the numbers of aged populations have risen considerably in the last few decades, the current coronavirus disease 2019 (COVID-19) has revealed an extensive vulnerability among these populations. Sarcopenia is an age-related disorder that increases hospitalization, dependencies, and mortality in older adults. It starts to develop in midlife or even earlier as a result of unbalanced diet/poor nutrition and low levels of physical activity, in addition to chronic disorders such as obesity and diabetes mellitus. Given that social isolation is adopted as the most protective measure against COVID-19, the level of physical activity and the intake of adequate diet have considerably declined, especially among older adults—denoting an increased possibility for developing sarcopenia. Research also shows a higher vulnerability of sarcopenic people to COVID-19 as well as the development of wasting disorders such as sarcopenia and cachexia in a considerable proportion of symptomatic and recovering COVID-19 patients. Muscular wasting in COVID-19 is associated with poor prognosis. Accordingly, early detection and proper management of sarcopenia and wasting conditions in older adults and COVID-19 patients may minimize morbidity and mortality during the current COVID-19 crisis. This review explored different aspects of screening for sarcopenia, stressing their relevance to the detection of altered muscular structure and performance in patients with COVID-19. Current guidelines recommend prior evaluation of muscle strength by simple measures such as grip strength to identify individuals with proven weakness who then would be screened for muscle mass loss. The latter is best measured by MRI and CT. However, due to the high cost and radiation risk entailed by these techniques, other simpler and cheaper techniques such as DXA and ultrasound are given preference. Muscle loss in COVID-19 patients was measured during the acute phase by CT scanning of the pectoralis muscle simultaneously during a routine check for lung fibrosis, which seems to be an efficient evaluation of sarcopenia among those patients with no additional cost. In recovering patients, muscle strength and physical performance have been evaluated by electromyography and traditional tests such as the six-minute walk test. Effective preventive and therapeutic interventions are necessary in order to prevent muscle loss and associated physical decline in COVID-19 patients.

Radiographic anatomy and clinical significance of percutaneous endoscopic transforaminal oblique fixation from posterior corner in lumbar spine.

BackgroundEndoscopic transforaminal decompression and interbody fusion (ETDIF) has been widely discussed due to its advantages of less trauma, less bleeding, quick recovery, high safety, and relatively fewer complications, as well as adverse factors such as incomplete decompression, steep learning curve, low fusion rate, and high radiation risk. Furthermore, this technique requires the use of supplemental posterior pedicle-screw. Decompression, interbody fusion and percutaneous pedicle screw implantation are not completed in a single channel. Percutaneous endoscopic transforaminal oblique fixation from posterior corner in lumbar spine (PETOFPC) overcomes the above limitations. The purpose of this study is to confirm the anatomical feasibility for PETOFPC in the posterolateral transforaminal approach and to provide anatomic data for the design of new integrated fixable and fused interbody cage.MethodsSixty volunteers (22 men and 38 women) who underwent lumbar CT scans were collected and sent to the GEAW4.4 workstation. As a cohort study, the distances and angles of each path in the sagittal and axial planes were measured and analyzed statistically.ResultsThe lengths of each path are not less than 40mm, and the longest can be up to 46mm. The paths in full-length group are about 5mm longer than that in medium group. PE (from point P to target E) path was the optimal path. The angles of each path were significantly different (P≤0.001), namely, a1 > a2 > a3, b1 > b2 > b3, and c1 < c2 < c3.ConclusionsThis study confirms anatomic feasibility for PETOFPC and provides anatomic data for the design of new integrated fixable and fused interbody cage. PETOFPC may be a very promising technology and have great clinical significance.

Lifetime attributable risk of cancer incidence and mortality in routine digital radiology procedures

PurposeDigital radiography has the potential to improve the practice of radiography but it also has the potential to significantly increase patient doses. Considering rapidly growing digital radiography in many centers, concerns rise about increasing the collective dose of the human population and following health effects. This study aimed to estimate organ and effective doses and calculate the lifetime attributable risk (LAR) of cancer incidence and mortality in digital radiography procedures in Iran. MethodsOrgan and effective doses of 12 routine digital radiography examinations including the skull, cervical spine, chest, thoracic spine, lumbar spine, pelvic and abdomen were estimated using PCXMC software based on Monte Carlo simulation method. Then, LARs of cancer incidence and mortality were estimated using the BEIR VII method. ResultsOrgan doses ranged from 0.01 to a maximum of 2.5 mGy while effective doses ranged from 0.01 to 0.7 mSv. Radiation risk showed dependence on the X-ray examination type and the patient's sex and age. In skull and cervical X-rays, the thyroid; in the chest and thoracic spine X-rays, the lung, and breast; and in the lumbar spine, pelvic and abdominal X-rays, the colon and bladder had the highest LAR of cancer incidence and mortality. Furthermore, younger patients and also females were at higher radiation risk. ConclusionThe lifetime attributable risk of cancer incidence and mortality due to radiation exposure is not trivial. Therefore efforts should be made to reduce patient doses while maintaining image quality.

Прогноз радиационных рисков населения на загрязнённых 137Cs территориях России в соответствии с современными рекомендациями МКРЗ

Purpose: Calculations of radiation detriment to the population currently living (in 2020) in the territories of Russia contaminated with 137Cs after the Chernobyl accident in 1986.&#x0D; Material and methods: Radiation detriment was calculated in two ways: according to the original ICRP method, and approximate calculation as the product of the nominal risk factor of RSS-99/2009 by the effective dose (nominal radiation detriment). For ICRP calculations, equivalent doses were estimated using the dose coefficients of the US Environmental Protection Agency (EPA). The number of the studied population at the beginning of 2020 was 142676 people, 65205 men and 77471 women. This is mainly the population of the Bryansk region and Tula region, 85.5 % and 10 % of the total population, respectively. The average accumulated effective dose of the population was 30.6 mSv, and the maximum individual accumulated dose was 707 mSv.&#x0D; Results: In 2020, for men at the age of 44 and for women at the age of 55, the nominal radiation detriment is approximately equal to the value of radiation detriment calculated using the ICRP method. At the same time, the nominal detriment is significantly (up to 2.3 times) underestimated for younger and overestimated for older ages. In 2020, the critical population groups with the highest accumulated doses and maximum radiation detriment are men aged 34 and women aged 35. For these population groups, the average accumulated effective doses were 35.3 mSv and 39.2 mSv, and the average radiation detriment was 2.6×10–3 and 4.2×10–3, for men and women, respectively. For 11.8 % of the population (8.3 % of men and 14.8 % of women), the individual radiation detriment calculated using the ICRP method exceeds the value of 3.5×10–3, which corresponds to the maximum increase in individual risk for the population over 70 years of exposure, established by RSS-99/2009 for normal exposure conditions. The maximum radiation detriment of 3.9×10–2 was found for a woman of the Krasnogorsky district of the Bryansk region at the age of 37 years, with an accumulated effective dose of 392 mSv.&#x0D; Conclusion: The results of this work can be used in preparing recommendations to health authorities on improving medical supervision of exposured citizens living in areas contaminated with radionuclides, as well as in developing regulatory documents for the provision of targeted medical care to people from high radiation risk groups using personalized medicine methods.

Biologically-based modeling of radiation risk and biomarker prevalence for papillary thyroid cancer in Japanese a-bomb survivors 1958–2005

Purpose Thyroid cancer of papillary histology (PTC) is the dominant type in radio-epidemiological cohorts established after nuclear accidents or warfare. Studies on post-Chernobyl PTC and on thyroid cancer in the life span study (LSS) of Japanese a-bomb survivors consistently revealed high radiation risk after exposure during childhood and adolescence. For post-Chernobyl risk assessment overexpression of the CLIP2 gene was proposed as molecular biomarker to separate radiogenic from sporadic PTC. Based on such binary marker a biologically-based risk model of PTC carcinogenesis has been developed for observational Chernobyl data. The model featured two independent molecular pathways of disease development, of which one was associated with radiation exposure. To gain credibility the concept for a mechanistic risk model must be based on general biological features which transcend findings in a single cohort. The purpose of the present study is therefore to demonstrate portability of the model concept by application to PTC incidence data in the LSS. By exploiting the molecular two-path concept we improve the determination of the probability of radiation causing cancer (POC). Materials and methods The current analysis uses thyroid cancer incidence data of the LSS with thyroid cancer diagnoses and papillary histology (n = 292) from the follow-up period between 1958 and 2005. Risk analysis was performed with both descriptive and biologically-based models. Results Judged by goodness-of-fit all applied models described the data almost equally well. They yielded similar risk estimates in cohorts post-Chernobyl and LSS. The preferred mechanistic model was selected by biological plausibility. It reflected important features of an imperfect radiation marker which are not easily addressed by descriptive models. Precise model predictions of marker prevalence in strata of epidemiological covariables can be tested by molecular measurements. Application of the radiation-related molecular pathway from our preferred model in retrospective risk assessment decreases the threshold dose for 50% POC from 0.33 (95% confidence interval (CI) 0.18; 0.64) Gy to 0.04 (95% CI 0.01; 0.19) Gy for females and from 0.43 (95% CI 0.17; 1.84) Gy to 0.19 (95% CI 0.05; 1.00) Gy for males. These improvements are still not sufficient to separate radiation-induced from sporadic PTC cases at very low doses <0.015 Gy typical for the Fukushima accident. Conclusions Successful application of our preferred mechanistic model to LSS incidence data confirms and improves the biological two-path concept of radiation-induced PTC. Model predictions suggest further molecular validation studies to consolidate the basis of biologically-based risk estimation.

Parenting in a warming world: thermoregulatory responses to heat stress in an endangered seabird.

The frequency of extreme weather events, including heat waves, is increasing with climate change. The thermoregulatory demands resulting from hotter weather can have catastrophic impacts on animals, leading to mass mortalities. Although less dramatic, animals also experience physiological costs below, but approaching, critical temperature thresholds. These costs may be particularly constraining during reproduction, when parents must balance thermoregulation against breeding activities. Such challenges should be acute among seabirds, which often nest in locations exposed to high solar radiation and predation risk. The globally endangered bank cormorant Phalacrocorax neglectus breeds in southern Africa in the winter, giving little scope for poleward or phenological shifts in the face of increasing temperatures. Physiological studies of endangered species sensitive to human disturbance, like the bank cormorant, are challenging, because individuals cannot be captured for experimental research. Using a novel, non-invasive, videographic approach, we investigated the thermoregulatory responses of this seabird across a range of environmental temperatures at three nesting colonies. The time birds spent gular fluttering, a behaviour enhancing evaporative heat loss, increased with temperature. Crouching or standing birds spent considerably less time gular fluttering than birds sitting on nests (ca 30% less at 22°C), showing that postural adjustments mediate exposure to heat stress and enhance water conservation. Crouching or standing, however, increases the vulnerability of eggs and chicks to suboptimal temperatures and/or expose nest contents to predation, suggesting that parents may trade-off thermoregulatory demands against offspring survival. We modelled thermoregulatory responses under future climate scenarios and found that nest-bound bank cormorants will gular flutter almost continuously for several hours a day by 2100. The associated increase in water loss may lead to dehydration, forcing birds to prioritize survival over breeding, a trade-off that would ultimately deteriorate the conservation status of this species.

Radiometric and petrographic characterization of sediment samples collected from Jhelum, Neelum and Kunhar Rivers of Muzaffarabad, Azad Kashmir

In the present study, we present results of radiometric and petrographic analyses of sediment samples collected from the river banks of Jhelum, Neelum, and Kunhar confluencing in the district Muzaffarabad. Gamma activity concentrations due to 226Ra, 232Th, and 40K were determined using high-purity germanium detector (HPGe). For a total of thirty sediment samples collected from three rivers, the activity concentrations of 226Ra, 232Th and 40K varied from 03.32 ± 0.40 to 100.45 ± 2.08 Bq Kg−1, 02.17 ± 1.35 to 298.42 ± 4.50 Bq Kg−1 and 37.88 ± 11.66 to 1386.32 ± 30.17 Bq Kg−1 with mean values of 36.91 ± 1.12, 61.57 ± 2.81 and 557.33 ± 19.81 Bq Kg−1, respectively. The overall value of Raeq for all the investigated sediment samples was found to be in the range from 9.34 ± 3.23 to 633.53 ± 10.14 Bq Kg−1 with mean value of 167.88 ± 6.66 Bq Kg−1. The values estimated for hazard indices, viz., external hazard index (Hex), internal hazard index (Hin), representative index (Ir), gamma index (I) and alpha index (Iα) for all sediment samples were found to be in the range from 0.02 ± 0.008 to 1.71 ± 0.03, 0.034 ± 0.009 to 1.98 ± 0.03, 0.07 ± 0.02 to 4.57 ± 0.07, 0.03 ± 0.01 to 2.29 ± 0.03 and 0.02 ± 0.002 to 0.50 ± 0.010 with mean values of 0.45 ± 0.02, 0.55 ± 0.02, 1.23 ± 0.04, 0.62 ± 0.02 and 0.18 ± 0.010, respectively. The activity concentrations were subsequently used to estimate the terrestrial gamma ray absorbed dose rate in air at 1 m above the ground and annual effective dose. For all the samples, the values of gamma absorbed dose rate and annual effective dose ranged from 4.42 ± 1.49 to 284.24 ± 4.64 nGyh−1 and 0.027 ± 0.009 to 1.74 ± 0.03 mSv year−1 with mean values of 77.49 ± 3.04 nGyh−1 and 0.48 ± 0.02 mSv year−1, respectively. Mean gamma absorbed dose rate computed in the present study is higher than that reported for world average (59 nGy h−1) and it also exceeds the UNSCEAR proposed safe limit of 55 nGyh−1. The resulting annual effective dose is also higher than the worldwide average value of 0.07 mSv year−1, however, it is less than the safe limit of 1 mSv year−1. From the present study, it is concluded that there is a possibility of high radiation risk from the sediments of the surveyed rivers due to elevated activity concentrations and doses when used as building materials. The building codes need to be revisited taking into account the effects of radiation exposure and absorbed dose on the inhabitants.

Comparison of the diagnostic accuracy of diffusion-weighted magnetic resonance imaging and positron emission tomography/computed tomography in pulmonary nodules: a prospective study.

PurposeComputed tomography (CT) and positron emission tomography (PET) are the mainstay imaging methods in the evaluation and follow-up of pulmonary nodules. But they both have high radiation risk for patients. Diffusion- weighted magnetic resonance imaging (DW-MRI), on the other hand, is a radiation free imaging method that gives information about the biological structure of tissues at the molecular level by measuring random movement of water in biological tissues. In this prospective study we aimed to compare the computed tomography characteristics of the nodules in terms of malignancy and to compare the accuracy of DW-MRI and PET/CT results in those patients.Material and methodsSeventy-six patients suspicious for lung cancer on thorax CT imaging were prospectively further evaluated by thorax diffusion-weighted imaging and PET/CT. Pulmonary lesion characteristics, apparent diffusion coefficient (ADC), and maximum standardised uptake values (SUVmax) were compared with histopathological results.ResultsThere was statistically significant moderate negative correlation between PET-SUVmax and ADC values of lung lesions. ADC values below the cut-off was 97.1%, specificity was 97.6%, positive predictive value was 97.1%, and the negative predictive value was 97.6%.ConclusionsDAG-MRI and PET/CT have similar success in the differentiation of benign and malignant lung lesions.

Paediatric Dose AssessmentToward Establishment of National Diagnostic Reference Levels for Digital Radiography Examinations in Iran

Introduction: Paediatric patients deserve special attention because of the higher radiation risks compared with adults. The main purpose of this study is to determine patient dose and diagnostic reference level for Paediatric through Entrance Surface Dose (ESD) calculations in common X-ray examination and to establish Paediatric national DRLs in digital radiography in Iran. Materials and Methods: The study was performed on 5260 patients in 53 X-ray room. They are classified into four age groups, 0>1 year, 1>5 years, 5>10 years and 10>15 years old. Skull (PA), Skull (Lat), Chest (PA), Chest (Lat), Pelvis(AP), Abdomen (AP) digital X-ray examination is done for them. The dosimetry protocol in this study was indirect method to measure Entrance Surface Air Kerma (ESAK). The X-ray tube output for each equipment is measured using RTI solid state detector (Model Barracuda). Finally, the third quarter determined diagnostic reference level. Results: Based on the results of this study, national diagnostic reference levels were established: for example, for age group 0 to 1-year-old: 0.51 mGy for Skull(AP/PA), 0.46 mGy for Skull(Lat), 0.11 mGy for Cervical spine(AP), 0.11 mGy for Cervical spine(Lat), 0.06mGy for Chest(PA), 0.08 mGy Chest(Lat), 0.15 mGy for Thoracic spine(AP), 0.26 mGy for Thoracic spine (Lat), 0.48 mGy for Lumbar spine (AP), 0.74 mGy for Lumbar spine(Lat), 0.47 mGy for Pelvis (AP) and 0.47 mGy for Abdomen (AP). Conclusion: This article has determined wide variations in radiation dose of x-ray examinations among hospitals in Iran. Application of a diagnostic reference levels (DRL) could be a optimization procedure for reducing patients dose. The survey reveals significant variations in the radiological practices.

Freeze-dried diethylenetriaminepentaacetic acid-functionalized polymeric micelles containing paclitaxel: A kit formulation for theranostic application in cancer

Polymeric micelles (PM) are versatile nanoparticles with suitable properties to tumor delivery of hydrophobic drugs such as paclitaxel (PTX) and imaging probes such as technetium-99 m. However, instability of drug content in aqueous medium and obstacles related to lengthy radiolabeling procedures, high radiation exposure and risk of human error limit its clinical application. Freeze-dried kit formulation might be a strategy to overcome these issues. Thus, we developed a freeze-dried kit formulation containing diethylenetriaminepentaacetic acid (DTPA)-functionalized 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy(polyethyleneglycol)-2000] polymeric micelles carrying PTX (PM-DTPA/PTX) for application in the diagnosis and/or treatment of solid tumors. PM-DTPA/PTX were prepared and the physical and radiochemical characteristics (size, zeta potential, PTX content and radiolabeling yields) evaluated before lyophilization process and after storage up to 180 days. In vivo biodistribution studies were performed in 4T1 breast tumor-bearing BALB/c mice. A freeze-dried kit containing PM-DTPA/PTX showed high storage stability in all parameters evaluate up to 180 days since no significant alteration was observed at all evaluated timeframes. The freeze-drying process did not change the physicochemical and biological properties of the PM, including the property of tumor targeting. Therefore, a stable freeze-dried kit containing PM-DTPA/PTX was developed as an easy and fast preparation and showed high potential for theranostic application in cancer treatment.

Preliminary investigations on reducing the high radiation risk level of TENORM scale waste from petroleum industry

Abstract The main objective of this study is directed to remove 226Ra, 228Ra radionuclides from TENORM scale waste without seriously degradation the physicochemical characteristics of soils or generating waste. It was found that 82, 87% removal of total radioactivity using successive washing by commercial and TX-100 solutions, respectively, after seven cycles. Some radiation risk before and after treatment with surfactants were determined. It is a promising and efficient as well as economic process. Our results from this task could provide a useful information for defining the establishing and operating on a pilot-scale plant for efficient and economic TENORM treatment.

Low-dose CT for lung cancer screening: opportunities and challenges.

Lung cancer is among the most frequently diagnosed cancers worldwide and the leading cause of cancer death in both males and females. Screening for lung cancer coupled with earlier intervention has long been studied as an approach to mortality reduction. However, minimal progress was achieved until recently, when lowdose spiral computed tomography (LDCT) screening demonstrated a 20% reduction in mortality from lung cancer in a randomized controlled trial (RCT), the National Lung Screening Trial, from the United States. On the basis of this finding, LDCT has been recommended for lung cancer screening in high-risk populations by several clinical guidelines. However, results from the following independent RCTs in Europe failed to show consistent conclusions. In addition, intractable problems gradually emerged with the progress of LDCTscreening. This paper summarizes and discusses the main observations and challenges of LDCT screening for lung cancer. Before spreading implementation of LDCTscreening, challenges, including high false-positive rates, overdiagnosis, enormous costs, and radiation risk, must be addressed. Complementary biomarkers and technical improvement are expected in the field of lung cancer screening in the near future.

Radiological Risks Assessment of Ogun State Drinking Water

The presence of radionuclides in water constitute health risk to man. The consumption of such water increases the likelihood of incurring cancer. Analysis will enhance the detection of significant radionuclides causing harm to the populace and stimulate remediation. This inferred the radioactivity measurements of twenty (20) well water samples from three industrial cities of Ogun State using Hyper Pure Germanium detector (HPGe). The pH and other physiochemical parameters were also determined. The result showed that the mean activity concentrations of 40K, 210Pb, 224Ra, 232Th and 238U were found to be 1.86±1.70 Bql−1; 7.93±2.40 Bql−1; 3.60±1.25 Bql−1; 8.48±2.10 Bql−1; and 2.28±0.57 Bql−1 respectively. The corresponding mean total annual effective dose for ages 0-1 y; 1-2 y; 2-7 y; 7-12 y; 12-17 y and > 17 y are: 9.14 mSv y−1; 9.58 mSv y−1; 6.87 mSv y−1; 6.86 mSv y−1; 11.91 mSv y−1; and 5.68 mSv y−1 respectively. The mean cancer mortality and morbidity risks respectively are: {(3.16 and 5.00)10−5} for 40K; {(575.74 and 759.67)10−5} for 210Pb; {(43.25 and 71.05)10−5} for 224Ra; {(63.37 and 96.03)10−5} for232Th; and {(10.70 and 16.40)10−5} for 238U. The activity concentrations of 210Pb, 224Ra and 232Th exceeded the World Health Organization (WHO) guidance level in all samples but one. The corresponding total annual effective dose for all the six age groups exceeded the recommended WHO standard of 0.1 mSv y−1 in all samples. More importantly, there is high radiation risk in drinking the water from these wells and 210Pb contribution to risk was the highest

Vertebroplasty versus kyphoplasty: a comparative study of safety and cost-effectiveness and tips to improve outcomes of vertebroplasty

Background Vertebroplasty (VP) has been found to be effective in treating persistent pain resulting from osteoporotic vertebral fractures. It brings rapid and significant pain relief but shows high rates of cement leakage (CL) and does not restore lost vertebral height. Kyphoplasty (KP) can partially restore vertebral height with minimal risk for CL but is very expensive, time consuming, and exposes surgeons to higher radiation risk. Patients and methods Thirty-one patients who underwent either VP or KP were included in the study. VP technique was refined to minimize complications and maximize outcome. VP was performed unipedicularly, whereas KP was performed usually bipedicularly (except for two patients). Pain relief and functional outcome were evaluated using the Visual Analogue Scale and the Oswestry Disability Index. Radiographs were used to evaluate CL, vertebral height restoration, and cemented vertebral body fraction. Results Twenty patients underwent VP and 11 patients underwent KP. The mean duration was 45.5 and 70.9 min for VP and KP, respectively. The mean number of C-arm images was 46 and 163 images for VP and KP, respectively. The mean reduction in Visual Analogue Scale was 7.2 and 7.6 points for VP and KP, respectively. The mean reduction in the Oswestry Disability Index was 66.3 and 72.1 points for VP and KP, respectively. The mean regain in vertebral height was 19.7 and 42.5% after VP and KP, respectively. Symptomatic adjacent level fractures occurred in two VP patients and one KP patient. Conclusion KP is more effective compared with VP in terms of vertebral height restoration, but is very expensive, time consuming, and entails more radiation exposure to surgeons compared with VP. Both techniques are equally effective as regards pain relief. CL can be minimized by refining VP technique.