Enrichment of naturally occurring radionuclides and trace elements in Yatagan and Yenikoy coal-fired thermal power plants, Turkey

Publication date: August 2018
Source:Journal of Environmental Radioactivity, Volume 188
Author(s): Banu Ozden, Erkan Guler, Taavi Vaasma, Maria Horvath, Madis Kiisk, Tibor Kovacs
Coal, residues and waste produced by the combustion of the coal contain naturally occurring radionuclides such as ²³⁸U, ²²⁶Ra, ²¹⁰Pb, ²³²Th and ⁴⁰K and trace elements such as Cd, Cr, Pb, Ni and Zn. In this work, coal and its combustion residues collected from Yatagan and Yenikoy coal fired thermal power plants (CPPs) in Turkey were studied to determine the concentrations of natural radionuclides and trace elements, and their enrichments factors to better understand the radionuclide concentration processes within the combustion system. In addition, the utilization of coal fly ash as a secondary raw material in building industry was also studied in terms of radiological aspects. Fly ash samples were taken at different stages along the emission control system of the thermal power plants. Activity concentrations of naturally occurring radionuclides were determined with Canberra Broad Energy Germanium (BEGe) detector BE3830-P and ORTEC Soloist PIPS type semiconductor detector. The particle size distribution and trace elements contents were determined in various ash fractions by the laser scattering particle size distribution analyzer and inductively coupled plasma (ICP-OES). From the obtained data, natural radionuclides tend to condense on fly ash with and the activity concentrations increase as the temperature drop in CPPs. Measured ²¹⁰Pb and ²¹⁰Po concentration varied between 186 ± 20–1153 ± 44 Bq kg⁻¹, and 56 ± 5–1174 ± 45 Bq kg⁻¹, respectively. The highest ²¹⁰Pb and ²¹⁰Po activity concentrations were determined in fly ash taken from the temporary storage point as 1153 ± 44 Bq kg⁻¹ and 1174 ± 45 Bq kg⁻¹, respectively. There were significant differences in the activity concentrations of some natural radionuclide and trace elements (Pb and Zn) contents in ash fractions among the sampling point inside both of the plants (ANOVA, p < 0.001). Coal and ash sample analysis showed an increase activity concentration and enrichment factors towards the electrostatic precipitators for both of the power plants. The enrichment factors for Zn follow a similar trend as Pb, increasing in value towards the end of the emission control system. The calculated activity indexes were above 1.0 value for both of the power plants, assuming the utilization of fly ash at 100%. It can be concluded that the reuse of fly ash as a secondary raw material may not be hazardous depending on the percentage of utilization of ash.



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A Comparison of Neuroradiology and Pediatric Radiology Job Boards

Publication date: Available online 19 March 2018
Source:Current Problems in Diagnostic Radiology
Author(s): Cory M Pfeifer




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Variability in the Use of Simulation for Procedural Training in Radiology Residency: Opportunities for Improvement

Publication date: Available online 19 March 2018
Source:Current Problems in Diagnostic Radiology
Author(s): Shanna A. Matalon, Sona A. Chikarmane, Eren D. Yeh, Stacy E. Smith, William W. Mayo-Smith, Catherine S. Giess
ObjectiveIncreased attention to quality and safety has led to a re-evaluation of the classic apprenticeship model for procedural training. Many have proposed simulation as a supplementary teaching tool. The purpose of this study was to assess radiology resident exposure to procedural training and procedural simulation.Materials and MethodsAn IRB-exempt online survey was distributed to current radiology residents in the United States by e-mail. Survey results were summarized using frequency and percentages. Chi-square tests were used for statistical analysis where appropriate.Results353 current residents completed the survey. Thirty-seven percent (n=129/353) of respondents had never used procedure simulation. Of the residents who had used simulation, most did not do so until after having already performed procedures on patients (59%, n=132/223). The presence of a dedicated simulation center was reported by over half of residents (56%, n=196/353) and was associated with prior simulation experience (P=.007). Residents who had not had procedural simulation were somewhat likely or highly likely (3 and 4 on a 4-point Likert-scale) to participate if it were available (81%, n=104/129). Simulation training was associated with higher comfort levels in performing procedures (P<.001).ConclusionsAlthough procedural simulation training is associated with higher comfort levels when performing procedures, there is variable use in radiology resident training and its use is not currently optimized. Given the increased emphasis on patient safety, these results suggest the need to increase procedural simulation use during residency, including an earlier introduction to simulation prior to patient exposure.



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The Nine Habits of Highly Effective Radiologists

Publication date: Available online 19 March 2018
Source:Current Problems in Diagnostic Radiology
Author(s): Timothy Alves, Monica Kalume-Brigido, Corrie Yablon, Puneet Bhargava, David Fessell
Stephen R. Covey′s landmark work in the field of effectiveness and professional development delineated first seven, then ultimately eight, habits of highly effective people with applicability to all professions.¹ This article describes the eight habits in specific relation to the radiologist, and proposes a ninth habit to help one bring a positive and centered approach during the journey to effectiveness and beyond.



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Radiotherapy induced cavernomas in adult cancer patients

Publication date: Available online 19 March 2018
Source:Radiotherapy and Oncology
Author(s): Bernardo Cacho-Díaz, Karen Salmerón-Moreno, Nydia Lorenzana-Mendoza, Armando Reyes, Sergio I. Valdés-Ferrer, Gabriela Gómez-Ahumada, Gervith Reyes-Soto, Ángel Herrera-Gómez
Cerebral Cavernomas (CC) are vascular malformations located in the Central Nervous System (CNS) characterized by endothelium-lined vascular channels without parenchyma between them, whose main risk is hemorrhage. The aim of this study is to report adult cancer patients that developed CC after radiotherapy (RT) to the CNS during oncological surveillance.



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MR Imaging of the Prostate

Publication date: March 2018
Source:Radiologic Clinics of North America, Volume 56, Issue 2
Author(s): Aytekin Oto




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Management of Incidental Lung Nodules

Publication date: Available online 7 March 2018
Source:Radiologic Clinics of North America
Author(s): Jeffrey B. Alpert, Jane P. Ko

Teaser

Incidentally detected lung nodules are increasingly common in routine diagnostic computed tomography (CT) imaging. Formal management recommendations for incidental nodules, such as those outlined by the Fleischner Society, must therefore reflect a balance of malignancy risk and the clinical context in which nodules are discovered. Nodule size, attenuation, morphology, and location all influence the likelihood of malignancy and, thus, the necessity and timing of follow-up according to current Fleischner recommendations. As technological advancements in CT imaging continue, there may be greater reliance on advanced computerized analysis of lung nodule features to help determine the risk of clinically significant disease.


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Lung Cancer Biopsies

Publication date: Available online 7 March 2018
Source:Radiologic Clinics of North America
Author(s): Amita Sharma, Jo-Anne O. Shepard

Teaser

Image-guided percutaneous transthoracic needle biopsy (PTNB) is a well-established and minimally invasive technique for evaluating pulmonary nodules. Implementation of a national lung screening program and increased use of chest computed tomography have contributed to the frequent identification of indeterminate pulmonary nodules that may require tissue sampling. The advent of biomarker-driven lung cancer therapy has led to increased use of repeat PTNB after diagnosis. Percutaneous insertion of markers for preoperative localization of small nodules can aid in minimally invasive surgery and radiation treatment planning. This article discusses PTNB, patient selection, and biopsy technique, including minimizing and managing complications.


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Missed Lung Cancer

Publication date: Available online 7 March 2018
Source:Radiologic Clinics of North America
Author(s): Rydhwana Hossain, Carol C. Wu, Patricia M. de Groot, Brett W. Carter, Matthew D. Gilman, Gerald F. Abbott

Teaser

The chest radiograph is one of the most commonly used imaging studies and is the modality of choice for initial evaluation of many common clinical scenarios. Over the last two decades, chest computed tomography has been increasingly used for a wide variety of indications, including respiratory illnesses, trauma, oncologic staging, and more recently lung cancer screening. Diagnostic radiologists should be familiar with the common causes of missed lung cancers on imaging studies in order to avoid detection and interpretation errors. Failure to detect these lesions can potentially have serious implications for both patients as well as the interpreting radiologist.


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Copyright

Publication date: March 2018
Source:Radiologic Clinics of North America, Volume 56, Issue 2





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Staging Lung Cancer

Publication date: Available online 7 March 2018
Source:Radiologic Clinics of North America
Author(s): Girish S. Shroff, Chitra Viswanathan, Brett W. Carter, Marcelo F. Benveniste, Mylene T. Truong, Bradley S. Sabloff

Teaser

The updated eighth edition of the tumor, node, metastasis (TNM) classification for lung cancer includes revisions to T and M descriptors. In terms of the M descriptor, the classification of intrathoracic metastatic disease as M1a is unchanged from TNM-7. Extrathoracic metastatic disease, which was classified as M1b in TNM-7, is now subdivided into M1b (single metastasis, single organ) and M1c (multiple metastases in one or multiple organs) descriptors. In this article, the rationale for changes in the M descriptors, the utility of preoperative staging with PET/computed tomography, and the treatment options available for patients with oligometastatic disease are discussed.


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Contributors

Publication date: March 2018
Source:Radiologic Clinics of North America, Volume 56, Issue 2





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Contents

Publication date: March 2018
Source:Radiologic Clinics of North America, Volume 56, Issue 2





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CME Accreditation Page

Publication date: March 2018
Source:Radiologic Clinics of North America, Volume 56, Issue 2





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Forthcoming Issues

Publication date: March 2018
Source:Radiologic Clinics of North America, Volume 56, Issue 2





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The important role of the peer-reviewer

Very soon after having accepted the position of section editor for Oral and Maxillofacial Surgery in the journal Oral Surgery Oral Medicine Oral Pathology Oral Radiology, I quickly discovered one of the most stressful tasks encountered by all editors of peer-reviewed scientific journals. How does one find an appropriate reviewer who will provide a meaningful critical review, in a timely fashion in order to avoid publication delays?

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Radiotherapy induced cavernomas in adult cancer patients

Cerebral Cavernomas (CC) are vascular malformations located in the Central Nervous System (CNS) characterized by endothelium-lined vascular channels without parenchyma between them, whose main risk is hemorrhage. The aim of this study is to report adult cancer patients that developed CC after radiotherapy (RT) to the CNS during oncological surveillance.

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The important role of the peer-reviewer

Publication date: Available online 19 March 2018
Source:Oral Surgery, Oral Medicine, Oral Pathology and Oral Radiology
Author(s): Joshua E. Lubek




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Postmortem computed tomography findings of airway occlusion caused by a plastic bag: A case report of suspected fatal asphyxia

Publication date: Available online 17 March 2018
Source:Journal of Forensic Radiology and Imaging
Author(s): Rutsuko Yamaguchi, Go Inokuchi, Yohsuke Makino, Hiroki Mukai, Maiko Yoshida, Shumari Urabe, Hirotaro Iwase




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Periprocedural Management in Transthoracic Needle Biopsy: Review of the Current Evidence

Abstract

Purpose of Review

Transthoracic needle biopsy (TTNB) is a common diagnostic tool with expanding clinical indications. While most literature on this topic has focused on complications and techniques, this review will examine the evidence for periprocedural care specific to lung biopsy.

Recent Findings

Review of the literature reveals great heterogeneity in clinical practice regarding periprocedural management of TTNB, for example, in terms of post-procedural monitoring as well as strategies for dealing with potential complications of TTNB. This is on the basis of a relative paucity of systematic clinical studies to guide management specific to the procedure.

Summary

Further studies focused on periprocedural management in TTNB are needed to establish evidence-based guidelines that address the unique clinical aspects and complications of this procedure.

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Pitfalls in the Diagnosis of Acute Pulmonary Embolism on Computed Tomography: Common Pathologic and Imaging Mimics

Abstract

Purpose of Review

Acute pulmonary embolism (PE) is the third most-common acute cardiovascular disease in the United States. Nearly 900,000 new diagnoses are made each year, with 250,000 associated hospitalizations and up to 100,000 deaths (Palacio et al. in Semin Roentgenol 50(3):217–225, 2015; Metter et al. in Am J Roentgenol 208(3):489–494, 2017; Jaff et al. in Circulation 123(16):1788–830, 2011). Timely and accurate diagnosis of acute PE is crucial for the prevention of most deaths associated with PE, even more so than optimal medical therapy (Palacio et al. in Semin Roentgenol 50(3):217–225, 2015; Jaff et al. in Circulation 123(16):1788–830, 2011; Raja et al. in Ann Intern Med 163(9):701, 2015).

Recent Findings

Computed tomography (CT) has emerged as the primary imaging modality used in the diagnosis of acute PE. Thus, radiologists play a key role in the correct diagnosis of acute PE, and must differentiate this diagnosis from other conditions that mimic the imaging findings of acute PE, as well as from artifacts associated with imaging techniques (Palacio et al. in Semin Roentgenol 50(3):217–225, 2015; Jaff et al. in Circulation 123(16):1788–830, 2011; Raja et al. in Ann Intern Med 163(9):701, 2015). Understanding how these diagnoses present on CT is necessary for improved patient care.

Summary

This article will discuss the diagnosis of acute PE with CT, the diagnosis of diseases that may be mistaken for acute PE, and how to identify imaging artifacts that may be mistaken for an acute PE.

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Editorial Board

Publication date: August 2018
Source:Journal of Environmental Radioactivity, Volume 188





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Kinetics of 3H, 90Sr and 137Cs content changes in hydrosphere in the Vltava River system (Czech Republic)

Publication date: August 2018
Source:Journal of Environmental Radioactivity, Volume 188
Author(s): Eduard Hanslík, Diana Marešová, Eva Juranová, Barbora Sedlářová
The paper presents results and interpretation of long-term monitoring of occurrence and behaviour of radioisotopes ³H, ⁹⁰Sr, and ¹³⁷Cs in the vicinity of the Temelín Nuclear Power Plant. ³H, ⁹⁰Sr, and ¹³⁷Cs originate predominantly from residual contamination due to atmospheric nuclear weapons tests and the Chernobyl disaster in the last century. Monitoring of radionuclides comprised surface waters, river sediments, aquatic plants, and fish. This enables an up-to-date appraisal of the Temelín Nuclear Power Plant impact on the hydrosphere in all indicators at standard power plant operation, as well as at critical situations. The time and spatial variability of these radionuclide concentrations were monitored in the hydrosphere at in- and out-flow of the Orlík Water Reservoir. The basic evaluated radioecological characteristics can be used in assessing the long-term kinetics of decline and behaviour of radionuclides and their potential release into the environment. A very slow decline in ³H concentration at unaffected sites was observed. At sites downstream from the power plant the ³H concentrations were significantly higher, an evident impact of the power plant operation. A decline in ⁹⁰Sr and ¹³⁷Cs concentrations was observed in all the monitored indicators. Also, the characteristic effective and ecological half-lives were evaluated.



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Assessment of uranium release to the environment from a disabled uranium mine in Brazil

Publication date: August 2018
Source:Journal of Environmental Radioactivity, Volume 188
Author(s): Wagner de Souza Pereira, Alphonse Germaine Albert Charles Kelecom, Ademir Xavier da Silva, Alessander Sá do Carmo, Delcy de Azavedo Py Júnior
The Ore Treatment Unit (in Portuguese Unidade de Tratamento de Minérios - UTM) located in Caldas, MG, Brazil is a disabled uranium mine. Environmental conditions generate acid drainage leaching metals and radionuclides from the waste rock pile. This drainage is treated to remove the heavy metals and radionuclides, before allowing the release of the effluent to the environment. To validate the treatment, samples of the released effluents were collected at the interface of the installation with the environment. Sampling was carried out from 2010 to 2015, and the activity concentration (AC, in Bq·l⁻¹) of uranium in the liquid effluent was analyzed by arzenazo UV-Vis spectrophotometry of the soluble and particulate fractions, and of the sum of both fractions. Descriptive statistics, Z test and Pearson R² correlation among the fractions were performed. Then, the data were organized by year and both ANOVA and Tukey test were carried out to group the means by magnitude of AC. The annual mean ranged from 0.02 Bq·l⁻¹ in 2015 to 0.11 Bq·l⁻¹ in 2010. The soluble fraction showed a higher AC mean when compared to the mean of the particulate fraction and no correlation of the data could be observed. Concerning the magnitude of the release, the ANOVA associated with the Tukey test, identified three groups of annual means (AC2010> AC2011 = AC2012 = AC2013 = AC2014 > AC2015). The mean values of uranium release at the interface installation-environment checking point (point 014) were within the Authorized Annual Limit (AAL) set by the regulator (0.2 Bq·l⁻¹) indicating compliance of treatment with the licensing established for the unit. Finally, the data showed a decreasing tendency of U release.



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Improvement of in-situ gamma spectrometry methods by Monte-Carlo simulations

Publication date: August 2018
Source:Journal of Environmental Radioactivity, Volume 188
Author(s): Dusan Mrdja, Kristina Bikit, Sofija Forkapic, Istvan Bikit, Jaroslav Slivka, Jan Hansman
Performing in-situ measurements of gamma radiation originating from soil requires adequate detection efficiency curves, which can be obtained by Monte-Carlo simulations. In simulations, soil density of 1.046 g/cm³ was used, with the following elemental composition of soil in which gamma radiation was generated: O - 47%, Si −35%, Al - 8%, Fe - 3.9%, C - 2.1%, Ca - 1.4%, K - 1.3%, N - 0.6%, Mg - 0.6%, N - 0.1%. Soil matrix was represented by cylindrical volume of 1.5 m diameter and 0.5m thickness, while germanium detector was placed at 1 m height above the soil. The simulated gamma spectrum, originated from K-40, as well as from members of Th-232 chain, and daughters of Ra-226, was obtained. Homogeneous distribution of various radionuclides (Ra-226, Th-232, K-40) in soil matrix is considered in this work. Gamma spectra obtained in simulations were analyzed, and together with simulated detection efficiency data they provide comparison with real experimental measurements and practical application of results derived by Monte-Carlo simulations. As a result of this work, the corresponding detection efficiency curve for HPGe detector was obtained, which can be applied for in-situ measurements of radionuclide concentration in soil, assuming uniform radionuclide distribution.In order to validate our simulation results regarding detection efficiency, we performed in-situ measurements of soil radioactivity and compared the obtained activity concentrations with laboratory measurements. We found a good agreement, within activity concentration uncertainty, between in-situ measurement results and average values of activity concentrations obtained by laboratory measurements.



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Sources of inflow and nature of redistribution of 90Sr in the salt lakes of the Crimea

Publication date: August 2018
Source:Journal of Environmental Radioactivity, Volume 188
Author(s): N.Yu. Mirzoyeva, S.I. Arkhipova, N.V. Kravchenko
At the first time for the period after the Chernobyl NPP accident the nature of the redistribution of the ⁹⁰Sr concentrations in components of the ecosystems of the salt lakes of the Crimea were identified and described. Concentration of ⁹⁰Sr in water of the salt lakes depends on the sources of the inflow this radionuclide into aquatic ecosystems and salinity level of lakes water. Until April 2014 the flow of the Dnieper river water through the Northern-Crimean canal was more important factor of contamination of salt lakes of the Crimea by ⁹⁰Sr, than atmospheric fallout of this radionuclide after the Chernobyl NPP accident. Concentrations of ⁹⁰Sr in water of the salt lakes of the Crimea exceeded 2.4–156.5 times its concentrations in their bottom sediments. The ⁹⁰Sr dose commitments to hydrophytes, which were sampled from the salt lakes of the Crimea have not reached values which could impact them during entire the after-accident period.



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Rapid in-situ radiometric assessment of the Mrima-Kiruku high background radiation anomaly complex of Kenya

Publication date: August 2018
Source:Journal of Environmental Radioactivity, Volume 188
Author(s): M.I. Kaniu, H.K. Angeyo, I.G. Darby, L.M. Muia
This paper presents the radiometric survey results of the Mrima-Kiruku high background radiation (HBR) anomaly complex of south coastal Kenya. Utilizing a portable γ-ray spectrometer consisting of a 2.0 l NaI(Tl) backpack detector integrated with GPS to perform the relevant in-situ radiometric measurements, a novel geospatial gating method was devised to represent the measurements. The goal of this study was to assess radiation exposure and associated natural radioactivity levels in the complex and to compare the results obtained with those from previous preliminary related studies. Absorbed dose-rates in air were found to range <60–2368 nGy h⁻¹. These rates were observed to correspond with the spatial variability of the underlying geology and terrain, increasing toward the summits of both Mrima and Kiruku Hills which implies that the complex is a geogenic HBR anomaly. The activity concentrations of ²³²Th in the study area are generally higher than those of ⁴⁰K and ²³⁸U: The means of ⁴⁰K, ²³⁸U and ²³²Th ranged 235±19–603±28 Bq kg⁻¹, 68±6–326±24 Bq kg⁻¹ and 386±12–1817±51 Bq kg⁻¹ respectively. It was concluded that the high air absorbed dose-rate values that were measured (>600 nGy h⁻¹) are due to elevated activity concentrations of ²³²Th. Therefore there is significant (>1 mSv/y) radiological hazard to the inhabitants of the area particularly those who reside at the foothills of both Mrima and Kiruku Hills.



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InSiCal – A tool for calculating calibration factors and activity concentrations in in situ gamma spectrometry

Publication date: August 2018
Source:Journal of Environmental Radioactivity, Volume 188
Author(s): Alexander Mauring, Tim Vidmar, Torbjörn Gäfvert, Jon Drefvelin, Aldo Fazio
In situ gamma spectrometry is a widely applied analysis technique for the determination of radioactivity levels in soil. Compared to traditional laboratory analysis of soil samples, in situ techniques offer a quick and low-cost way of obtaining accurate results from on-site measurements. However, although the technique is well-known, the dependence of in situ gamma spectrometry on complex and time-consuming calibration procedures as well as in-depth knowledge of the geometric distribution of the source in the ground deters many potential users from employing it in their routine work. Aiming to alleviate this issue, a software tool named InSiCal (In Situ gamma spectrometry Calculator) has been developed to make in situ gamma spectrometry more accessible to both experts and non-experts in the field. This is done by simplifying and streamlining both calibration and activity calculation through a simple and intuitive graphical user interface. Testing in real field conditions show that InSiCal is capable of yielding results which are in very good agreement with soil sample analyses, and that the results may be obtained using different detector types (HPGe, NaI, LaBr and CZT). Overall, InSiCal, provides results which are comparable in accuracy to laboratory measurements, indicating that it fulfills its purpose successfully.



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Distribution and migration of 239+240Pu in abiotic components of the Black Sea ecosystems during the post-Chernobyl period

Publication date: August 2018
Source:Journal of Environmental Radioactivity, Volume 188
Author(s): N.N. Tereshchenko, S.B. Gulin, V. Yu Proskurnin
Distribution of ^239,240Pu in abiotic components (water and bottom sediment) of the Black Sea ecosystems was studied during the post-Chernobyl period at different offshore and near-shore locations. The trends of these radionuclides accumulation by sediments were analyzed. The spatial-temporal changes in the ^239,240Pu distribution as well as effective half-life for these radionuclides in the Black Sea surface water in deep-sea area are presented. The estimations of the average annual removal fluxes of the ^239,240Pu into the bottom sediments were obtained. The Black Sea sediments were characterized by a higher ^239,240Pu concentration factor (Cf ≈ n·10⁴–n·10⁶) and radiocapacity factor (F(^239,240Pu) was about 99.9% on the shelf, 94.5–99.1% on deep-sea basin for silty and 94.6–98.9% on the shelf for sandy bottom sediments) as compared with Cf and F for ¹³⁷Cs and ⁹⁰Sr. Silty bottom sediments play the role of ^239,240Pu main depot in the Black Sea ecosystem. The studied radioecological characteristics of Pu allowed us to define the type of plutonium biogeochemical behavior in the Black Sea as a pedotropic one. The results of this complex radioecological monitoring of ^239+240Pu contamination in the Black Sea and their analysis makes it possible to understand the plutonium redistribution pathways which will enable to carry out the tracing of its migration within the ecosystems.



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Evaluation of mean transit time of aerosols from the area of origin to the Arctic with 210Pb/210Po daily monitoring data

Publication date: August 2018
Source:Journal of Environmental Radioactivity, Volume 188
Author(s): Weihua Zhang, Baki Sadi, Christopher Rinaldo, Jing Chen, Norman Spencer, Kurt Ungar
In this study, the activity concentrations of ²¹⁰Pb and ²¹⁰Po on the 22 daily air filter samples, collected at CTBT Yellowknife station from September 2015 to April 2016, were analysed. To estimate the time scale of atmospheric long-range transport aerosol bearing ²¹⁰Pb in the Arctic during winter, the mean transit time of aerosol bearing ²¹⁰Pb from its origin was determined based on the activity ratios of ²¹⁰Po/²¹⁰Pb and the parent-progeny decay/ingrowth equation. The activity ratios of ²¹⁰Po/²¹⁰Pb varied between 0.06 and 0.21 with a median value of 0.11. The aerosol mean transit time based the activity ratio of ²¹⁰Po/²¹⁰Pb suggests longer mean transit time of ²¹⁰Pb aerosols in winter (12 d) than in autumn (3.7 d) and spring (2.9 d).Four years ²¹⁰Pb and ²¹²Pb monitoring results and meteorological conditions at the Yellowknife station indicate that the ²¹²Pb activity is mostly of local origin, and that ²¹⁰Pb aerosol in wintertime are mainly from outside of the Arctic regions in common with other pollutants and sources contributing to the Arctic. The activity concentration ratios of ²¹⁰Pb and ²¹²Pb have a relatively constant value in summer with a significant peak observed in winter, centered in the month of February. Comparison of the ²¹⁰Pb/²¹²Pb activity ratios and the estimated mean ²¹⁰Pb transit time, the mean aerosol transit times were real reflection of the atmosphere transport characteristics, which can be used as a radio-chronometer for the transport of air masses to the Arctic region.



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Fast in situ gamma spectroscopy using hand-held spectrometer with NaI probe

Publication date: August 2018
Source:Journal of Environmental Radioactivity, Volume 188
Author(s): Szymon Guguła, Krzysztof Kozak, Jadwiga Mazur, Dominik Grządziel, Mariusz Mroczek
In this work a hand-held spectrometer InSpector 1000 with NaI (Tl) 2″ x 2″ detector has been adapted to fast in situ gamma-ray spectroscopy. Two specially designed mounting stands with shielding have been built, allowing conducting measurements in different geometries. Three particular geometries (NW, IS50, IS00) have been chosen for efficiency calibration and further study. The first one (NW) is intended for small environmental samples (volume ca 140 cm³) collected on site. IS50 geometry is a typical in situ geometry meant for radioactivity measurements in soil with detector pointed towards the ground. In this geometry the probe is shielded and mounted 50 cm above the soil surface. The new proposed geometry IS00 is designed in the way that the detector is inserted directly into the soil in order to increase the counting efficiency. The methods of efficiency calibration involved using calibration standards (in NW geometry) and the results obtained in previous in situ measurements with InSpector 2000 portable spectrometer with HPGe detector and ISOCS™ Shield Systems, which is routinely used in environmental measurements.NW geometry turned out to be useful for natural radioisotopes concentrations (K-40, U-238 and Th-232), which significantly exceed typical values of those concentrations observed in Poland. Both IS50 and IS00 geometries are applicative for quick (2 h long measurement) evaluation of typical concentrations of K, U and Th in soils. The newly proposed geometry IS00 is superior as it showed lower detection limits and uncertainties as well as its handling was far easier than of IS50. Authors have proven that hand-held spectrometer InSpector 1000, together with mounting stands and shielding, can be successfully used for fast in situ gamma-spectroscopy. Its relatively small weight and good mobility are additional assets. Moreover, detailed procedures for measurements in each geometry have been developed to conduct such analyses properly.



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Application of ISOCS system in the laboratory efficiency calibration

Publication date: August 2018
Source:Journal of Environmental Radioactivity, Volume 188
Author(s): Dominik Grządziel, Krzysztof Kozak, Jadwiga Mazur, Mariusz Mroczek
ISOCS (In Situ Counting Object System) from Canberra is applied in laboratory for creating efficiency calibrations of good quality without using radioactive standards. Besides of typical sample containers used in laboratory, ISOSC system also allows modelling containers and objects of almost any shape and elemental composition.The study was based on gamma spectrometry with HPGe semiconductor detector with electronics and software spectrum analysis GENIE 2000 + ISOCS. Measuring set is equipped with portable shield system with set of collimators ISOCS Shield Systems Model ISOXSHLD from Canberra. This shielding system provides attenuation of gamma background radiation with average value 33 (for gamma energies from 186 keV to 2615.5 keV).The portable shield system can be used for low-background laboratory measurements. For this purpose a measuring vessel of new geometry was constructed: the polystyrene cylinder with a height of 40 mm and a diameter of 70 mm. The efficiency calibration for this container was performed using both ISOCS system and classical calibration standard in the same geometry. In order to verify the correctness of performed calibration procedures, the measurements of radioactive standard CBSS 2 were made. The results of both calibrations were compared with the data from the standard certificate. Satisfactory agreement was achieved. Mean percentage difference between results from ISOCS calibration compared to reference values is 6% for all isotopes activities in CBSS 2 standard.The set of collimators was used to develop efficiency calibration for in situ measurements of the soil surface. Test measurements were carried out at the area of the Institute of Nuclear Physics Polish Academy of Sciences in Kraków, Poland (IFJ PAN). Two measurement methods were compared: in situ and laboratory gamma spectroscopy. The obtained average results (from all 10 measuring points) are consistent within the range of measurement uncertainty.



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Assessment of dose rate to terrestrial biota in the area around coal fired power plant applying ERICA tool and RESRAD BIOTA code

Publication date: August 2018
Source:Journal of Environmental Radioactivity, Volume 188
Author(s): Mirjana Ćujić, Snežana Dragović
This paper presents the environmental radiation risk assessment based on two software program approaches ERICA Tool (version 1.2) and RESRAD BIOTA (version 1.5) to estimate dose rates to terrestrial biota in the area around the largest coal fired power plant in Serbia. For dose rate assessment software's default reference animals and plants and the best estimated values of activity concentrations of ²³⁸U, ²³⁴U, ²³⁴Th, ²³²Th, ²³⁰Th, ²²⁶Ra, ²¹⁰Pb, ²¹⁰Po, ¹³⁷Cs in soil were used. Both approaches revealed the highest contribution to the internal dose rate due to ²²⁶Ra and ²¹⁰Po, while ¹³⁷Cs contributed the most to the external dose rate. In the investigated area total dose rate to biota derived using ERICA Tool ranged from 0.3 to 14.4 μGy h⁻¹. The natural radionuclides exhibited significantly higher contribution to the total dose rate than the artificial one. In the investigated area, only dose rate for lichens and bryophytes exceeded ERICA Tool screening value of total dose rate of 10 μGy h⁻¹ suggested as confident that environmental risks are negligible. The assessed total dose rates for reference animals and plants using RESRAD BIOTA were found to be 7 and 3 μGy h⁻¹, respectively. In RESRAD BIOTA - Level 3, 10 species (Lumbricus terrestris, Rana lessonae, Sciurus vulgaris, Anas platyrhynchos, Lepus europaeus, Vulpes vulpes, Capreolus capreolus, Suss crofa, Quercu srobur, Tilia spp.) representative for the study area were modeled. Among them the highest total dose rate (4.5 μGy h⁻¹) was obtained for large mammals. Differences in the predicted dose rates to biota using the two software programs are the consequence of the difference in the values of transfer parameters used to calculate activity concentrations in biota. Doses of ionizing radiation estimated in this study will not exhibit deterministic effects at the population level. Thus, the obtained results indicate no significant radiation impact of coal fired power plant operation on terrestrial biota. This paper confirms the use ERICA Tool and RESRAD BIOTA softwares as flexible and effective means of radiation impact assessment.



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Treatment of Wide-Necked Bifurcation Aneurysms

Abstract

Background

Recently, numerous devices dedicated to the treatment of wide-necked aneurysms have become available. We present our initial experience with the pCANvas device and present the technical success rate, clinical outcome and immediate angiographic occlusion rates.

Objective

We sought to determine the efficacy of flow with the pCANvas for the treatment of unruptured intracranial aneurysms.

Methods

We performed a retrospective review of our prospectively collected data to identify patients treated with the pCANvas device between February 2015 and February 2017. The patient demographics, aneurysm characteristics, immediate and delayed clinical and radiographic follow-up data were recorded.

Results

We identified 17 patients (13 female) treated only with the pCANvas device. The average age of the patients was 60.5 ± 13.3 years (range 25–75 years). The average dome width was 7.6 ± 3.2 mm (range 3–15.8 mm), dome height 7.1 ± 3.2 mm (range 3–12.9 mm) and neck width 5.4 ± 3.2 (range 3–16.3 mm). The average aspect ratio was 1.5 ± 0.8 (range 0.6–3.7). At the end of the procedure 15 aneurysms continued complete filling of the aneurysm (Raymond Roy Classification[RRC] 3) with 2 aneurysms showing only filling of the neck of the aneurysm (RRC 2). Early follow-up angiography was available for 16 patients and at this stage 11 aneurysms showed persistent and complete filling of the aneurysm (RRC 3), 5 aneurysms showed complete occlusion of the aneurysm (RRC 1) and 7 aneurysms underwent repeat treatment with coiling.

Conclusion

The early results on the use of the pCANvas are promising; however, longer term follow-up and larger studies are required.

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Besonderheiten des Röntgen-Thorax im Kindesalter

Zusammenfassung

Die Aufnahmetechnik der Thoraxaufnahme im Kindesalter unterscheidet sich erheblich von der bei Erwachsenen. Fast immer reicht die ap/pa-Aufnahme aus, nur selten ist eine seitliche Aufnahme notwendig. In den ersten Lebensjahren kann der Thymus das Herz, das Gefäßband und die Lungenhili überlagern. Wichtige Leitstrukturen für die Analyse pathologischer Befunde der Lungen und des Mediastinums sind die Trachea mit der Bifurkation, die großen Bronchien und die Gefäße. Zur Beurteilung überblähter Lungen und intrathorakaler Verdichtungen sind genaue Kenntnisse der Anatomie im Kindesalter und von Fehlbildungen, welche die Atemwege, das Herz, die systemischen Gefäße und die Lungengefäße betreffen können, unerlässlich. Erkrankungen der Pleura und der Thoraxwand sollten immer auch mit Ultraschall untersucht werden. Maligne Erkrankungen sind selten, mit Ausnahme maligner Lymphome. In der Diagnostik komplexer Vitien, komplexer Lungenfehlbildungen, der zystischen Fibrose und in der Diagnostik aller Tumorerkrankungen ist die Computertomographie (CT) und/oder Magnetresonanztomographie (MRT) für die richtigen Therapieentscheidungen notwendig.

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Tumor microenvironment – Unknown niche with powerful therapeutic potential

Publication date: May–June 2018
Source:Reports of Practical Oncology & Radiotherapy, Volume 23, Issue 3
Author(s): Tomasz Kolenda, Weronika Przybyła, Marta Kapałczyńska, Anna Teresiak, Maria Zajączkowska, Renata Bliźniak, Katarzyna M. Lamperska
Head and neck squamous cell carcinomas (HNSCC) are in a group of cancers that are the most resistant to treatment. The survival rate of HNSCC patients has been still very low since last 20 years. The existence of relationship between oncogenic and surrounding cells is probably the reason for a poor response to treatment. Fibroblasts are an important element of tumor stroma which increases tumor cells ability to proliferate. Another highly resistance, tumorigenic and metastatic cell population in tumor microenvironment are cancer initiating cells (CICs). The population of cancer initiating cells can be found regardless of differentiation status of cancer and they seem to be crucial for HNSCC development.In this review, we describe the current state of knowledge about HNSCC biological and physiological tumor microenvironment.



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CyberKnife Stereotactic Radiosurgery in brain metastases: A report from Latin America with literature review

Publication date: May–June 2018
Source:Reports of Practical Oncology & Radiotherapy, Volume 23, Issue 3
Author(s): Cuauhtémoc de la Peña, Jorge H. Guajardo, María F. Gonzalez, César González, Benjamín Cruz
Background and aimStereotactic radiosurgery is increasingly being employed for the treatment of brain metastases, both as an adjuvant to surgical resection, and also as a primary treatment modality. The aim of this study is to evaluate overall survival and local control in patients with brain metastases treated with CyberKnife Stereotactic Radiosurgery (CKRS), due to the lack of evidence reported in Latin America.Materials and methodsWe performed a retrospective chart review from October 2011 to January 2017 of 49 patients with 152 brain metastases. Clinical and prognostic factors were further analyzed by independent analysis. Kaplan–Meier curves were constructed for overall survival and local control. The median follow-up period was 12 months (range, 1–37 months).ResultsThe median age was 61 years (range, 27–85 years) and Karnofsky performance status >70 in 96% of the patients. The median overall survival rate was 15.5 months (95% confidence interval [CI], 10.23–24.3 months). Overall 3-month, 6-month and 1-year local control rates were 98% (95% CI, 85–99%), 96% (95% CI, 82–99%), and 90% (94% IC, 76–96%), respectively. Local failure (LF) was observed in 6 patients (18 lesions). No late complications, such as radiation necrosis, were observed during the follow-up period.ConclusionsCKRS achieves excellent overall survival and local control rates with low toxicity in patients with brain metastases.



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4D modeling in a gimbaled linear accelerator by using gold anchor markers

Publication date: May–June 2018
Source:Reports of Practical Oncology & Radiotherapy, Volume 23, Issue 3
Author(s): Hideharu Miura, Shuichi Ozawa, Takaaki Matsuura, Atsushi Kawakubo, Fumika Hosono, Kiyoshi Yamada, Yasushi Nagata
PurposeThe purpose of this study was to verify whether the dynamic tumor tracking (DTT) feature of a Vero4DRT system performs with 10-mm-long and 0.28mm diameter gold anchor markers.MethodsGold anchor markers with a length of 10mm and a diameter of 0.28mm were used. Gold anchor markers were injected with short and long types into bolus material. These markers were sandwiched by a Tough Water (TW) phantom in the bolus material. For the investigation of 4-dimensional (4D) modeling feasibility under various phantom thicknesses, the TW phantom was added at 2cm intervals (in upper and lower each by 1cm). A programmable respiratory motion table was used to simulate breathing-induced organ motion, with an amplitude of 30mm and a breathing cycle of 3s. X-ray imaging parameters of 80kV and 125kV (320mA and 5ms) were used. The least detection error of the fiducial marker was defined as the 4D-modeling limitation.ResultsThe 4D modeling process was attempted using short and long marker types and its limitation with the short and long types was with phantom thicknesses of 6 and 10cm at 80kV and 125kV, respectively. However, the loss in detectability of the gold anchor because of 4D-modeling errors was found to be approximately 6% (2/31) with a phantom thickness of 2cm under 125kV. 4D-modeling could be performed except under the described conditions.ConclusionsThis work showed that a 10-mm-long gold anchor marker in short and long types can be used with DTT for short water equivalent path length site, such as lung cancer patients, in the Vero4DRT system.



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Evaluation of high-grade astrocytoma recurrence patterns after radiotherapy in the era of temozolomide: A single institution experience

Publication date: May–June 2018
Source:Reports of Practical Oncology & Radiotherapy, Volume 23, Issue 3
Author(s): Arno Lotar Cordova Jr., Taynná Vernalha Rocha Almeida, Cintia Mara da Silva, Pedro Argolo Piedade, Cristiane Maria Almeida, Carlos Genesio Bezzera Lima Jr., Carolina Dutra, Rafael Martins Ferreira, Marcelo Neves Linhares, Valeriy Denyak
AimEvaluating the recurrence patterns of high-grade astrocytomas in patients who were treated with radiotherapy (RT) plus temozolomide (TMZ).BackgroundThe current literature suggests that reducing the margins added to the CTV does not significantly change the risk of recurrence and overall survival; thus, we decided to analyze our data and to examine the possibility of changing the adopted margins.Materials and methodsFrom February 2008 till September 2013, 55 patients were treated for high-grade astrocytomas, 20 patients who had been confirmed to have recurrence were selected for the present study. Post-operative MRI was superimposed on the planning CT images in order to correlate the anatomical structures with the treatment targets. Recurrences were defined according to the Response Assessment Criteria for Glioblastoma. The mean margins of the PTVinitial and PTVboost were 1.2cm and 1.4cm, respectively. The analysis of the percentage of the recurrence volume (Volrec) within the 100% isodose surface was based on the following criteria: (I) Central: >95% of the Volrec; (II) In-field: 81–95% of the Volrec; (III) Marginal: 20–80% of the Volrec; and (IV) Outside: <20% of the Volrec.ResultsOf the 20 patients, 13 presented with central recurrences, 3 with in-field recurrences, 2 with marginal recurrences and 2 with outside recurrences. Therefore, the lower Volrec within 100% of the prescribed dose was considered in the classification.ConclusionsOf the selected patients, 80% had ≥81–95% of the Volrec within 100% of the prescribed dose and predominantly had central or in-field recurrences. These results are comparable with those from the literature.



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CT-based attenuation correction and resolution compensation for I-123 IMP brain SPECT normal database: a multicenter phantom study

Abstract

Objective

Statistical image analysis of brain SPECT images has improved diagnostic accuracy for brain disorders. However, the results of statistical analysis vary depending on the institution even when they use a common normal database (NDB), due to different intrinsic spatial resolutions or correction methods. The present study aimed to evaluate the correction of spatial resolution differences between equipment and examine the differences in skull bone attenuation to construct a common NDB for use in multicenter settings.

Methods

The proposed acquisition and processing protocols were those routinely used at each participating center with additional triple energy window (TEW) scatter correction (SC) and computed tomography (CT) based attenuation correction (CTAC). A multicenter phantom study was conducted on six imaging systems in five centers, with either single photon emission computed tomography (SPECT) or SPECT/CT, and two brain phantoms. The gray/white matter I-123 activity ratio in the brain phantoms was 4, and they were enclosed in either an artificial adult male skull, 1300 Hounsfield units (HU), a female skull, 850 HU, or an acrylic cover. The cut-off frequency of the Butterworth filters was adjusted so that the spatial resolution was unified to a 17.9 mm full width at half maximum (FWHM), that of the lowest resolution system. The gray-to-white matter count ratios were measured from SPECT images and compared with the actual activity ratio. In addition, mean, standard deviation and coefficient of variation images were calculated after normalization and anatomical standardization to evaluate the variability of the NDB.

Results

The gray-to-white matter count ratio error without SC and attenuation correction (AC) was significantly larger for higher bone densities (p < 0.05). The count ratio error with TEW and CTAC was approximately 5% regardless of bone density. After adjustment of the spatial resolution in the SPECT images, the variability of the NDB decreased and was comparable to that of the NDB without correction.

Conclusion

The proposed protocol showed potential for constructing an appropriate common NDB from SPECT images with SC, AC and spatial resolution compensation.

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