Radiation Environment and Medicine (REM)

REM » Archives » REM Vol.8, No.2

Radiation Environment and Medicine Vol.8, No.2

  • Publisher : Hirosaki University press
  • Language : English
  • ISSN : 2423-9097 (PRINT), 2432-163X (ONLINE)
  • Release : September 2019
  • Issue : Hirosaki University Press
  • pp. 39-132

Articles

Special Contribution

Radiation Doses to Practitioners Caring for Victims of a Radiological Accident

  • Jason Davis*

  • Oak Ridge Institute for Science and Education, Oak Ridge Associated Universities, Oak Ridge, TN 37830, USA

     

    Radiat Environ Med(2019)8(2): 39-44

Abstract
  1. Introduction: Nuclear and Radiological incidents present unique patient care challenges.

Traditionally, the focus of radiological incident preparedness has been nuclear power plant

accidents. Emergency response planning now has a broader focus and addresses a range of

nuclear and radiological emergencies including acts of terrorism.

Basic actions of responders to radiological emergencies should not differ, in general, from those

taken in response to emergencies involving other hazardous material. The purpose of this project

was to model the potential radiation exposure to first responders and in receiving healthcare

facilities.

  1. Methods: Radiation doses to medical personnel were modeled both empirically and via computer

modeling. Simulated isotopes were selected based on their likelihood of being present during

a radiological incident, as well as their radiological characteristics. Working backward from a

regulatory dose limit, the amount of material on or in a victimʼs body needed to produce such a

dose was determined.

  1. Results: Calculations estimate a dose rate of 0.67 mSv h-1 to a practitioner caring for a Chernobyl

accident victim with 1,400 MBq of I-131 in the thyroid. A practitioner caring for a hypothetical

patient uniformly contaminated with 60Co, 137Cs, or 192Ir would be able to stay in close proximity to

the patient for 18.1, 33.7, or 54.7 hours, respectively, before they reached the IAEA threshold dose

for lifesaving activities.

  1. Conclusion: Information presented here may be used to educate healthcare workers on the

relative risk of lifesaving activities following a radiological or nuclear incident. The research

presented here can also be used to provide additional information that an Incident Commander

can use to make more informed decisions about evacuation, sheltering-in-place, defining radiation

hazard boundaries, and in-field radiological dose assessments of the radiation workers, responders, and members of the public.

Key words: emergency response, accident, dose assessment

Special Contribution

Validation of Popular Models Used in the Analysis of Specific Activity of Primordial Radionuclides in Environmental Samples through 1-D Analytical Modeling

  • Margaret Wairimu Chege1* and Jeremiah Monari Kebwaro2

  • 1Physics Department, Kenyatta University, Nairobi, Kenya

    2School of Pure and Applied Sciences, Karatina University, Karatina, Kenya

     

    Radiat Environ Med (2019)8(2):45-50

Abstract

A scientific model may be considered agreeable if it conforms to given scientific laws, in addition to being able to procure data that can be replicated to an acceptable level when other time-tested and proven methodologies are applied. For first-time researchers such as graduate students, choosing the right model is not always easy and some may opt for a particular model not because they are assured of its correctness, but because it has been used by peers before them. Such tendencies can inadvertently lead to the propagation of flawed models across generations of researchers. In the field of environmental radioactivity, the “comparison” and “conventional” models are frequently used in the evaluation of specific activity of primordial radionuclides in solids. Through one-dimensional (1-D) analytical modeling, this paper shows that while the conventional model conforms to given scientific laws, the comparison model does not since it wrongly assumes a linear between the intensity of gamma radiation through a solid and mass of the solid. A modified version of the comparison model that corrects for difference in mass between the solids being compared (sample of interest and certified reference material) is advanced.

Key words: 1-D modeling, model, conventional model, one-dimensional modeling

Special Contribution

Radiation Induced by Stander Signalling

  • Fiona M. Lyng*

  • Radiation and Environmental Science Centre, Technological University Dublin, Kevin St, Dublin D08 NF82, Ireland

     

    Radiat Environ Med (2019)8(2):51-58

Abstract

Radiation induced bystander effects are effects observed in unirradiated cells which receive signals

from irradiated cells. Bystander effects include DNA damage, chromosomal aberrations, changes

in gene expression, oncogenic transformation and cell death. Bystander signals can be transferred

to surrounding cells either by gap junctional intercellular communication or by the production of

soluble extracellular factors released from irradiated cells. Recently, exosomes have been shown

to play a role in transferring signals from irradiated to non-irradiated cells. This review summarises

a recent body of work on radiation induced bystander signalling, focusing on calcium, reactive

oxygen and nitrogen species and on membrane signalling.

Key words: Radiation induced bystander effects, signalling, calcium, reactive oxygen 32 species, reactive nitrogen species, membrane signalling

Review

Current Status of Dosimetry Tools for Clinical Proton Beams

  • Takahiro Kato1, 2*

  • 1Preparing Section for New Faculty of Medical Science, Fukushima Medical University,

    Hikarigaoka 1, Fukushima City, Fukushima 960-1295 Japan

    2Department of Radiation Physics and Technology, Southern Tohoku Proton Therapy Center,

    172-7choume, Yatsuyamada, Koriyama, Fukushima 963-8563 Japan

     

    Radiat Environ Med (2019)8(2):59-69

Abstract

The use of proton beams is increasing in radiation therapy due to the physical characteristics of

the Bragg curve, offering dosimetric advantages over conventional radiation. However, dosimetric

measurements are necessary for safe and accurate irradiation with clinical proton beams. The

accuracy of dosimetry should be considered in terms of the required dose at the target volume,

which in general, requires standard uncertainty levels of 3%–5%. Reference dosimetry should thus

be done with uncertainties well below those levels, typically better than 1%, by using cylindrical

ionization chambers. By contrast, for non-reference measurements, the use of other dosimeters

should be considered provided that the energy and linear energy transfer (LET) dependence of

the detector response has been checked against the ionization chambers. The response of films,

silicon diodes, and other available solid-state detectors exhibits strong energy or LET dependence,

and their use is limited to conditions with nearly constant LET. This review is described current

dosimetric tools and methods for use with proton beams in routine clinical practice.

 

Key words: proton beam, dosimetry, measurement, detector

Regular Article

Preliminary Study of Expression of γ -H2AX and 53BP1 in Medical Radiation Workers

  • Iin Kurnia Hasan Basri1*, Yanti Lusiyanti1, Nastiti Rahajeng1,Tur Rahardjo1, Darlina Yusuf1 and Setiawan Soetopo2

  • 1Center for Technology of Radiation Safety and Metrology National Nuclear Energy Agency Jl.

    Lebakbulus Raya No. 49 Jakarta, 12440 INDONESIA

    2Hasan Sadikin Hospital, Jl. Pasteur No.38 Bandung, 40161 Indonesia

     

    Radiat Environ Med (2019)8(2):70-76

Abstract

Currently a huge number of professional and technical personnel in medicine, dentistry,and veterinary medicine are exposed to radiation while administering various radiologic procedures such as diagnostic, therapeutic, interventional, and nuclear medicine. The radiation workers in medical area have risks to be exposed to ionizing radiation that also potentially cause DNA damage. In this study, 43 blood samples were taken from medical radiation workers in three hospitals (Hasan Sadikin, Medistra, and Betsaida Hospitals) and administrative staff served as control. They were grouped according to gender (man and woman) and duration of working time (0 – 20 and > 20 years). The expression of γ-H2AX and 53BPI foci was detected by using antibody of γ-H2AX Ser-139 and 53BPI under fluorescence microscope observation. The mean γ-H2AX and 53BPI foci in medical radiation worker and control were 0.22 and 0.12 and 0.38 and 0.17 respectively (P > 0.05). There was correlation between γ-H2AX foci and 53BP1 (P < 0.0001) and no statistically significant of γ-H2AX and 53BP1 foci in behalf on gender and duration of working time of radiation workers (P > 0.05). It can be concluded that potency of DNA damaged that detected by γ-H2AX and 53BP1 foci between medical radiation worker and administrative staff and their duration of working time was not different.

Key words: γ-H2AX, 53BP1, DNA damage, medical radiation worker

Regular Article

An Alternative Method for Screening Liquid in Bottles at Airports Using Low Energy X-ray Transmission Technique

  • Parkphum Orachorn, Nares Chankow* and Somyot Srisatit

  • Department of Nuclear Engineering, Faculty of Engineering, Chulalongkorn University Bangkok 10330, Thailand

     

    Radiat Environ Med (2019)8(2):77-84

Abstract

Since August 2006, each airline passenger has been allowed to carry only a maximum of 100 ml liquid in each container and a total of not more than 1,000 ml in carry-on luggage. This measure was adopted to prevent bringing sufficient amount of deleterious liquids such as flammable, combustible and explosive liquids into the aircraft. Several methods have been investigated and tested to screen liquids in bottles at airports but none of them has been accepted as a routine inspection method. This research introduces low energy X-ray/gamma-ray transmission technique using a small 238Pu isotopic source and a compact 25 mm3 CdTe detector. The linear attenuation coefficients of various kinds of liquids contained in bottles having different sizes and thickness at 13.6 – 43.5 keV were determined without measurement of transmitted X-rays from an empty identical container or the empty portion of the container. Attenuation factor of the container was obtained from the estimated or measured container thickness and the predetermined linear attenuation coefficient of the container material. The technique introduced here could clearly distinguish alcohol, fuel oil and other kinds of liquid from water contained in bottles and cans while its sensitivity is dependent upon radiation energy and diameter of the bottle. It could be concluded that the proposed method has potential application in screening liquids contained in bottles for aviation security but further investigation on using other X-ray sources and X-ray detectors is recommended.

 

Key words: X-ray, gamma-ray, liquid, airport security, aviation security, explosive

Regular Article

Apoptotic Induction Mechanism of X-ray Irradiation Combined with Hydrogen Peroxide

  • Satoshi Fujita1, Yoichiro Hosokawa1*, Ryo Saga1, Eichi Tsuruga1, Kazuhiko Okumura2,

    Kentaro Ohuchi2 and Morio Ochi3

  • 1Hirosaki University Graduate School of Health Sciences, 66-1, Hon-cho, Hirosaki, Aomori 036-8564, Japan.

    2Division of Recostractive Surgery for Oral and Maxillofacial Region, Department of Human Biology and Pathophysiology, School of Dentistry, Health Sciences University of Hokkaido, 1757 Kanazawa, Tobetsu-cho, Ishikari-gun, Hokkaido 061-0293, Japan

    3Division of Fixed Prosthodontics and Oral Implantology, Department of Oral Rehabilitation, School of Dentistry, Health Sciences University of Hokkaido, 1757 Kanazawa, Tobetsu-cho, Ishikari-gun, Hokkaido 061-0293, Japan

     

    Radiat Environ Med (2019)8(2):85-93

Abstract

Kochi oxydol-radiation therapy for unresectable carcinomas (KORTUC) is a clinical therapy, that combines X-ray irradiation and localized hydrogen peroxide. However few studies have reported the basic biological mechanism of action of KORTUC. Therefore we examined the effects of using a combination of hydrogen peroxide and X-ray irradiation on cell death. Cell viability of DU145, SAS, and HL60 cells decreased upon X-ray irradiation combined with exposure to hydrogen peroxide, compared to that on X-ray irradiation alone. DNA fragmentation of HL60 cells increased when cells were exposed to the combination treatment in comparison to X-ray irradiation, and apoptosis was considered to have increased. Abasic sites by DNA oxidative damage were observed early during X-ray irradiation, but no such increase was observed with hydrogen peroxide treatment. Caspase-3 and caspase-9 activities increased with all the three types of treatment, whereas caspase-8 showed high activity on treatment with hydrogen peroxide and the combination. The appearance of Bax and cytochrome c on X-ray irradiation and western blot analysis indicated the involvement of caspase-9 activation. Thus, cytochrome c was released via Bax, and the pathway leading directly from caspase-8 to caspase-3 was inferred to be induced with hydrogen peroxide treatment. The results suggested that hydrogen peroxide treatment induces apoptosis through a cascade that is different from that induced by irradiation, and combination with hydrogen peroxide is considered to enhance the effect of irradiation.

 

Key words: radiation, hydrogen peroxide (H2O2), apoptosis, caspase, KORTUC (Kochi oxydolradiation therapy for unresectable carcinomas)

Regular Article

Radon Priority Areas and Radon Extremes −−Initial Statistical Considerations

  • Peter Bossew*

  • German Federal Office for Radiation Protection, Köpenicker Allee 120-130, Berlin

     

    Radiat Environ Med (2019)8(2):94-104

Abstract

Radon is acknowledged an important health hazard. Indoor radon is believed to be the second cause of lung cancer after smoking. Therefore, indoor Rn has increasingly been subject to regulation for the last years; in Europe, the EU directive on basic safety standards for protection against ionizing radiation. Among other, it requires delineation of radon priority areas, i.e. areas in which action related to prevention and remediation of high indoor radon concentrations should be taken with priority. Whatever the exact definition of these areas, also in those not declared priority areas, high radon concentrations can occur, if with lower frequency. Arguing that also scattered instances of high radon, which are too scarce to justify declaring an area radon priority, deserve mitigation attention, a particular label might be given to these areas, indicating the presence of extremes within an otherwise non-priority area. First statistical considerations about radon extremes and anomalies are presented in this paper.

 

Key words: Radon priority area, anomaly, extreme

Regular Article

Extended Ordered-subsets Expectation-maximization Algorithm with Power Exponent for Noise-robust Image Reconstruction in Computed Tomography

  • Yusaku Yamaguchi1, Moe Kudo2, Takeshi Kojima3, Omar Mohammad Abou Al-Ola4 and Tetsuya Yoshinaga3

  • 1National Hospital Organization, Shikoku Medical Center for Children and Adults, 2-1-1 Senyu, Zentsuji, Kagawa 765-8507, Japan

    2Graduate School of Health Sciences, Tokushima University, 3-18-15 Kuramoto, Tokushima 770-8509, Japan

    3Institute of Biomedical Sciences, Tokushima University, 3-18-15 Kuramoto, Tokushima 770-8509, Japan

    4Faculty of Science, Tanta University, El-Giesh St., Tanta, Gharbia 31527, Egypt

     

    Radiat Environ Med (2019)8(2):105-112

Abstract

The maximum-likelihood expectation-maximization (ML-EM) algorithm is the most popular iterative reconstruction method in emission-computed tomography with a noise model based on the Poisson distribution. The ordered-subsets EM (OS-EM) algorithm is known owing to accelerating the convergence of the ML-EM algorithm with the drawback of slow convergence. In this paper, we propose an extended OS-EM algorithm with a power exponent. We theoretically prove the asymptotic stability of an equilibrium corresponding to the solution of the nonlinear hybrid dynamical system whose numerical discretization based on multiplicative calculus coincides with the extended OS-EM algorithm. We provide a numerical experiment to demonstrate the effectiveness of the proposed system and confirm the acceleration of the proposed method and the robustness against noise. The reconstruction of high-quality images made by the method even when the projection data is noisy allows patient dose reduction in clinical practice.

Key words: Computed tomography, Iterative reconstruction, Ordered-subsets expectation maximization algorithm, Continuous-time image reconstruction, Noise-robust image, reconstruction, Dose reduction

Note

Determination of Radon Mass Exhalation Rate in the Region of Highest Lung Cancer Incidence in India

  • LZ Chhangte1, PC Rohmingliana2, B. K. Sahoo3, B. K. Sapra3, Hmingchungnunga1, Vanramlawma1, Remlalsiama1, Z. Pachuau1 and B. Zoliana2*

  • 1Department of Physics, Department of Physics, Mizoram University, Tanhril, Aizawl Mizoram, 796004 India

    2Department of Physics, Mizoram University, Tanhril, Mizoram, 796004 India

    3Department of Electronics, Govt. Zirtiri Residential Science College, Aizawl, Mizoram, 796007 India

    4Radiological Physics & Advisory Division, Bhabha Atomic Research Centre, Mumbai, 400085 India

     

    Radiat Environ Med (2019)8(2):113-117

Abstract

Radon mass exhalation rate and radon flux from the soil are measured using Smart RnDuo detector in Saiha and Lawngtlai District of Mizoram, India during 2015-2016. Seasonal collection and analysis of soil samples were done from the study area under or near the dwellings. Inspite of being the region of highest lung cancer incidence area in India, the average mass exhalation rate and radon flux from the soil were found to be low, being 89.59 ± 1.83 mBq/kg/h and 66.66 ± 3.69 Bq/m2/h respectively. Soil type and its grain size which are important factors in determining the radon mass exhalation rate were further analysed and it was found that the soil was sandy type where larger grain sizes (mesh number 60-120) were dominant. Mizoram has high percentage (67%) of tobacco user from the population. Large consumption of tobacco and its products along with the life style of the people rather than radon are attribute to the high cancer incidence in these areas. In spite of lower than global average radon flux in the study area, effect of inhalation of the gas to cause lung cancer cannot be ignored.

 

Key words: Radon Mass exhalation rate, radon flux, Smart RnDuo detector, High lung cancer

Report

Experience in Individual Dose Estimation after the Fukushima Nuclear Accident Using Self-administered Questionnaires ─ Activities to Encourage Responses to the Questionnaires and Resulting Response Rate ─

  • Tetsuo Ishikawa*, Seiji Yasumura, Akira Sakai, Akira Ohtsuru, Makoto Miyazaki,

    Mitsuaki Hosoya, Tetsuya Ohira and Kenji Kamiya

  • Fukushima Medical University, Hikarigaoka 1, Fukushima City, Fukushima, 960-1295, Japan

     

    Radiat Environ Med (2019)8(2):118-126

Abstract

Following the Fukushima Daiichi Nuclear Power Plant accident, individual external doses have been estimated by obtaining information on peopleʼs behavior at an initial stage after the accident and combining it with ambient dose rate maps. Residents in Fukushima Prefecture were asked to fill in their behaviors on self-administered questionnaires. The rate of response to the questionnaires was in the 20% range several months after sending out the questionnaire by mail. However, the rate did not subsequently increase by much after that, so various activities were taken to raise the response rate. Major activities were (1) creating a questionnaire that was simpler to fill out, (2) approaching Fukushima residents directly at various venues to help them fill out questionnaires, and (3) using the mass media to encourage people to submit questionnaires. While these activities, carried out primarily from FY2012 to FY2015, helped increase the number of responses, the response rate for the entire prefecture did not increase by much, and was at 27.6% as of March 31, 2018. However, rates exceeded 50% in most municipalities of the Soso region, where the damaged nuclear power plant is located. It appears that the response rate roughly reflected the ambient dose rate level.

 

Key words: Fukushima accident, individual external dose, behavior survey, self-administered, questionnaire, response rate

Report

Introduction of the Radiation Emergency Medicine Course at REAC/TS and Impressions of It from the Viewpoint of Medical Students

  • Remi Tokonami1, Mitsuaki Yoshino1and Masahiro Hosoda2*

  • 1Student in the Hirosaki University School of Medicine, 5 Zaifu-cho, Hirosaki, Aomori 036-8562, Japan

    2Hirosaki University Graduate School of Health Sciences, 66-1 Hon-cho, Hirosaki, Aomori 036-8564, Japan

    This author is equivalent to the first author.

     

    Radiat Environ Med (2019)8(2):127-132

Abstract

Since 2008, Hirosaki University has been running several projects on radiation emergency medicine for the preparedness in radiation and nuclear accidents. Within the framework of these projects, staff members of Hirosaki University have participated in the Radiation Emergency Medicine Course at the Radiation Emergency Assistance Center/Training Site (REAC/TS) in the USA since 2009. In 2019, some medical students of Hirosaki University got the first opportunity to attend the training course conducted by REAC/TS. Radiation Emergency Medicine course was mainly emphasized on the practical aspects of initial hospital management for the patients who were exposed and/or contaminated through lectures and hands-on practical exercises. In addition to radiation knowledge, having the same training with people from different occupations, languages and cultures gave us valuable experiences in deepening communication abilities. All of us had a very exciting and fulfilling time during our stay in REAC/TS.

 

Key words: radiation emergency medicine, training course, REAC/TS, medical student, Hirosaki University

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