EVALUATION OF RADIATION DOSE IN DIFFERENT POSITIONS AROUND THE PATIENT TABLE DURING INTERVENTIONAL CARDIOLOGY PROJECTIONS

2019 ◽  
Vol 188 (2) ◽  
pp. 199-204
Author(s):  
Y Lahfi ◽  
A Ismail

Abstract The aim of the present study was to evaluate the radiation exposure around the patient table as relative to the cardiologist position dose value. The dose rates at eight points presuming staff positions were measured for PA, LAO 30° and RAO 30° radiographic projections, and then normalized to the cardiologist’s position dose-rate value. The results show that in PA and RAO 30° projections, the normalized dose rate was higher by 9–22% at the right side of the table at a distance of 50 cm, while it was higher up to 31% at the left side for the same measured points in the LAO 30°. The differences of normalized dose rates for the both table sides were lower and decreased at farther positions. The obtained results correspond to the recommendations of staff radiation protection in Cath-labs with regards to X-ray tube and detector positions.

Author(s):  
Amir Hamzah ◽  
Hery Adrial ◽  
Subiharto Subiharto

EVALUATION OF RADIATION DOSE RATE OF RSG-GAS REACTOR. The RSG-GAS reactor has been operated for 30 years. Since the nuclear reactor has been operated for a long time, aging process on its components may occur. One important parameter for maintaining the safety level of the RSG-GAS reactor is to maintain radiation exposure as low as possible, especially in the working area. The evaluation results should be able to demonstrate that the radiation exposure of the RSG-GAS is still safe for workers, communities and the surrounding environments. The purpose of this study is to evaluate radiation exposure in the working area to ensure that the operation of RSG-GAS is still safe for the next 10 years. The scope of this work is confirming the calculation results with the measured radiation dose in the RSG-GAS reactor working area. Measurement of radiation exposure is done by using the installed equipments at some points in the RSG-GAS working area and a portable radiation exposure measurement equipment. The calculations include performance of a modeling and analysis of dose rate distribution based on the composition and geometry data of RSG-GAS by using MCNP.  The analysis results show that the maximum dose rate at Level 0 m working area of RSG-GAS reactor is 3.0 mSv/h with a deviation of 6%, which is relatively close to the measurement value. The evaluation results show that the dose rate in RSG-GAS working area is below the limit value established by the Nuclear Energy Regulatory Agency of Indonesia (BAPETEN) of 10 mSv/h (for the average effective dose of 20 mSv/year). Therefore, it is concluded that the dose rate in RSG-GAS working area is safe for personnel..Kata kunci: dose rates, RSG-GAS, radiation safety, MCNP.


2014 ◽  
Vol 111 (10) ◽  
pp. E914-E923 ◽  
Author(s):  
Kouji H. Harada ◽  
Tamon Niisoe ◽  
Mie Imanaka ◽  
Tomoyuki Takahashi ◽  
Katsumi Amako ◽  
...  

Radiation dose rates were evaluated in three areas neighboring a restricted area within a 20- to 50-km radius of the Fukushima Daiichi Nuclear Power Plant in August–September 2012 and projected to 2022 and 2062. Study participants wore personal dosimeters measuring external dose equivalents, almost entirely from deposited radionuclides (groundshine). External dose rate equivalents owing to the accident averaged 1.03, 2.75, and 1.66 mSv/y in the village of Kawauchi, the Tamano area of Soma, and the Haramachi area of Minamisoma, respectively. Internal dose rates estimated from dietary intake of radiocesium averaged 0.0058, 0.019, and 0.0088 mSv/y in Kawauchi, Tamano, and Haramachi, respectively. Dose rates from inhalation of resuspended radiocesium were lower than 0.001 mSv/y. In 2012, the average annual doses from radiocesium were close to the average background radiation exposure (2 mSv/y) in Japan. Accounting only for the physical decay of radiocesium, mean annual dose rates in 2022 were estimated as 0.31, 0.87, and 0.53 mSv/y in Kawauchi, Tamano, and Haramachi, respectively. The simple and conservative estimates are comparable with variations in the background dose, and unlikely to exceed the ordinary permissible dose rate (1 mSv/y) for the majority of the Fukushima population. Health risk assessment indicates that post-2012 doses will increase lifetime solid cancer, leukemia, and breast cancer incidences by 1.06%, 0.03% and 0.28% respectively, in Tamano. This assessment was derived from short-term observation with uncertainties and did not evaluate the first-year dose and radioiodine exposure. Nevertheless, this estimate provides perspective on the long-term radiation exposure levels in the three regions.


2020 ◽  
Vol 287 (1937) ◽  
pp. 20201638
Author(s):  
Katherine E. Raines ◽  
Penelope R. Whitehorn ◽  
David Copplestone ◽  
Matthew C. Tinsley

The consequences for wildlife of living in radiologically contaminated environments are uncertain. Previous laboratory studies suggest insects are relatively radiation-resistant; however, some field studies from the Chernobyl Exclusion Zone report severe adverse effects at substantially lower radiation dose rates than expected. Here, we present the first laboratory investigation to study how environmentally relevant radiation exposure affects bumblebee life history, assessing the shape of the relationship between radiation exposure and fitness loss. Dose rates comparable to the Chernobyl Exclusion Zone (50–400 µGy h −1 ) impaired bumblebee reproduction and delayed colony growth but did not affect colony weight or longevity. Our best-fitting model for the effect of radiation dose rate on colony queen production had a strongly nonlinear concave relationship: exposure to only 100 µGy h −1 impaired reproduction by 30–45%, while further dose rate increases caused more modest additional reproductive impairment. Our data indicate that the practice of estimating effects of environmentally relevant low-dose rate exposure by extrapolating from high-dose rates may have considerably underestimated the effects of radiation. If our data can be generalized, they suggest insects suffer significant negative consequences at dose rates previously thought safe; we therefore advocate relevant revisions to the international framework for radiological protection of the environment.


2017 ◽  
Vol 2 (3) ◽  
pp. 242
Author(s):  
Raj Kumar ◽  
A.K. Singh

<p>Radiation countermeasures development was undertaken almost six decade ago at AFRRI, USA with the aim to protect military as well as civilian personals against accidental or deliberate radiation exposure. Later on, with the advancement of radiation technologies and exploration of X-ray or γ-rays for diagnostics and therapeutic purposes, probability of radiation exposure was enhanced multifold. Therefore, importance of radiation countermeasures development was recognised globally. However, despite the concentrated efforts, till date not a single FDA approved radio protective drug is available for emergency uses. Major impediments identified in this are included variability in radio protective efficacy with different experimental models, radiation dose rate, radiation types and differential radio sensitivity of various biological systems. No way to evaluate radio protective efficacy of an agent in human volunteers. It is sufficient to realise that uniform excellence may not be achieved in the area of radiation countermeasure development. However, practical excellence based on the radioprotector’s application scenario can be achieved. Different radiation accidental scenarios and feasible practical parameters of excellence for radiation countermeasure development for particular types of incidental, accidental or deliberated radiation exposure are described.</p>


2017 ◽  
Vol 62 (2) ◽  
pp. 13-27
Author(s):  
Julio Abel ◽  
Julio Abel

Purpose: The aim of the paper is to review the genesis and evolution of the concept termed dose and dose rate effectiveness factor or DDREF, to expose critiques on the concept and to suggest some curse of action on its use. Material and methods: Mainly using the UNSCEAR reporting and ICRP recommendations as the main reference material, the paper describes the evolution (since the 70’s) of the conundrum of inferring radiation risk at low dose and dose-rate. People are usually exposed to radiation at much lower doses and dose rates than those for which quantitative evaluations of incidence of radiation effects are available – a situation that tempted experts to search for a factor relating the epidemiological attribution of effects at high doses and dose-rates with the subjective inference of risk at low doses and dose-rates. The formal introduction and mathematical formulation of the concept by UNSCEAR and ICRP (in the 90’s), is recalled. It is then underlined that the latest UNSCEAR radiation risk estimates did not use a DDREF concept, making it de facto unneeded for purposes of radiation risk attribution. The paper also summarizes the continuous use of the concept for radiation protection purposes and related concerns as well as some current public misunderstandings and apprehension on the DDREF (particularly the aftermath of the Fukushima Dai’ichi NPP accident). It finally discusses epistemological weaknesses of the concept itself. Results: It seems that the DDREF has become superseded by scientific developments and its use has turned out to be unneeded for the purposes of radiation risk estimates. The concept also appears to be arguable for radiation protection purposes, visibly controversial and epistemologically questionable Conclusions: It is suggested that: (i) the use of the DDREF can be definitely abandoned for radiation risk estimates; (ii) while recognizing that radiation protection has different purposes than radiation risk estimation, the discontinuation of using a DDREF for radiation protection might also be considered; (iii) for radiation exposure situations for which there are available epidemiological information that can be scientifically tested (namely which is confirmable and verifiable and therefore falsifiable), radiation risks should continue to be attributed in terms of frequentistic probabilities; and, (iv) for radiation exposure situations for which direct scientific evidence of effects is unavailable or unfeasible to obtain, radiation risks may need to be inferred on the basis of indirect evidence, scientific reasoning and professional judgment aimed at estimating their plausibility in terms of subjective probabilities.


2005 ◽  
Vol 44 (03) ◽  
pp. 94-98 ◽  
Author(s):  
G. Wunderlich ◽  
K. Behge ◽  
Th. Schönmuth ◽  
J. Kotzerke ◽  
M. Andreeff

SummaryAim: The number of therapies with radiopharmaceuticals labelled with 188Re is increasing requiring the documentation of the beta radiation exposure Hp(0.07) of the staff at all working and production sites and during the application and follow-up of the patient according to the new German Radiation Protection Law (StrlSchV). However, data for β-radiation exposure are rare. Therefore, we determined the personal dose Hp(0.07) of the skin of the hands handling 188Re radiopharmaceuticals to identify steps of high radiation exposure and to optimize working conditions. Method: Thermoluminescence dosimeters (TLD 100) were fixed to the fingertips of the radiochemist, the physician and the nurse and compared to official ring dosimeters. In addition, to monitor radiation exposure continuously readable electronic beta- and gamma dosimeters EPD (Siemens) were used. At eight days in which therapies were performed these readings were evaluated. Results: Considering one therapy with a 188Re-labelled radiopharmaceutical the middle finger of the radiochemist (production) and the physician (application) showed a radiation burden of 894 and 664 μSv/GBq, respectively. The cumulative dose of the fingertips after eight days of therapy was 249 and 110 mSv for the radiochemist and physician, respectively. A cumulative finger dose after eight days of therapy of 17 and 38 μSv/GBq was found for physician and nurse leading to a Hp(0.07) of 3 and 6 mSv, respectively. Preparing the radiopharmaceutical labelled with 20GBq of 188Re the reading of the personal electronic dosimeter of the radiochemist showed a γ-dose rate H . p(10) of 55 μSv/h and a β-dose rate H . p(0.07) of 663 μSv/h which are obviously not representative for the true radiation dose to the skin of the fingertips. Conclusion: During therapy with 188Re-labelled radiopharmaceuticals the true radiation dose to the skin of the finger tips exceeds by far the readings of the official ring dosimeters as well as the continuously readable beta- and gamma dosimeters. This means a risk in exceeding the radiation limit of 500 mSv/a given in the German Radiation Protection Law (§55 StrSchV) primarily in the working field of the radiochemist and the administering physician.


2015 ◽  
Vol 6 ◽  
pp. 145-149
Author(s):  
F Gbaorun ◽  
D Terver

In this study, a Geiger Muller ionization counter has been used to investigate the variation of background radiation dose level with time in a typical x-ray machine room and its environment. This is to monitor the effect of x-ray exposure on the background ionizing radiation level. The results showed that within a period of 3 hours, the cumulative background radiation dose in the x-ray room grew from s s Gy to around 84 . 90 ́ 10 - 10 - an initial level of 38 . 78 ́ Gy compared with nearby rooms where the s cumulative radiation grew from almost zero to a maximum value of about 46 . 9 ́ Gy within the 10 - same period. It was observed that after a radiation exposure from the machine, the background s radiation dose rate took about 25 minutes to decay from a maximum level of around 45 ́ Gy/hr to 10 - - s 17 . 47 ́ 10 the background level about Gy/hr which was found to be higher than the background dose rates in other nearby locations. While the dose rate in the x-ray machine room was higher than the s 10 - maximum dose limit of 12 ́ Gy/hr recommended for members of the public by the International Committee for Radiation Protection (ICRP), the dose rates in the other locations studied in the neighbourhood of the x-ray machine were within the limit.


2020 ◽  
Vol 6 (2) ◽  
pp. 96-102
Author(s):  
Ida Septiyanti ◽  
M. Ardhi Khalif ◽  
Edi Daenur Anwar

Background: This study analyzes the Radiation Dose of the General X-ray Radiology Installation at Roemani Hospital  Muhammadiyah Semarang to determine the dose received by the radiographer, the community around the room and to know the value of the effectiveness of radiation protection and to determine the pattern of radiation exposure distribution in the general X-ray radiology installation room II.Methods: Measurements were taken during general X-ray exposure and without exposure using a 451P ion chamber survey. Measurement of dose data received by the radiographer and the community around the room is taken at the point of the operator’s room, service room, waiting room. As for the measurement of the effectiveness of radiation protection taken at the point in the operator’s room and the general X-ray II and the radiation distribution pattern taken at points A, B, C, D and E with a distance of 40 cm, 80 cm and 120 cm in the room general X-ray II.Result: The result of measurements in the operator room are 0.0354 µSv / hour, waiting rooms with a distance of 3.5 m at 0.0146 µSv / hour, in the service room and waiting room with a distance of 8 m at 0 µSv / hour. The value of the effectiveness of radiation protection in the operator station is 83.33% and the general X-ray II door is 84.09%.Conclusions: Based on the results of the data obtained the value of the dose received and the value of effectiveness is quite safe from excessive radiation exposure. The radiation distribution pattern, the farther the distance from the radiation source, the measured radiation exposure value will be lower. 


2021 ◽  
pp. 152660282110074
Author(s):  
Quirina M. B. de Ruiter ◽  
Frans L. Moll ◽  
Constantijn E. V. B. Hazenberg ◽  
Joost A. van Herwaarden

Introduction: While the operator radiation dose rates are correlated to patient radiation dose rates, discrepancies may exist in the effect size of each individual radiation dose predictors. An operator dose rate prediction model was developed, compared with the patient dose rate prediction model, and converted to an instant operator risk chart. Materials and Methods: The radiation dose rates (DRoperator for the operator and DRpatient for the patient) from 12,865 abdomen X-ray acquisitions were selected from 50 unique patients undergoing standard or complex endovascular aortic repair (EVAR) in the hybrid operating room with a fixed C-arm. The radiation dose rates were analyzed using a log-linear multivariable mixed model (with the patient as the random effect) and incorporated varying (patient and C-arm) radiation dose predictors combined with the vascular access site. The operator dose rate models were used to predict the expected radiation exposure duration until an operator may be at risk to reach the 20 mSv year dose limit. The dose rate prediction models were translated into an instant operator radiation risk chart. Results: In the multivariate patient and operator fluoroscopy dose rate models, lower DRoperator than DRpatient effect size was found for radiation protocol (2.06 for patient vs 1.4 for operator changing from low to medium protocol) and C-arm angulation. Comparable effect sizes for both DRoperator and DRpatient were found for body mass index (1.25 for patient and 1.27 for the operator) and irradiated field. A higher effect size for the DRoperator than DRpatient was found for C-arm rotation (1.24 for the patient vs 1.69 for the operator) and exchanging from femoral access site to brachial access (1.05 for patient vs 2.5 for the operator). Operators may reach their yearly 20 mSv year dose limit after 941 minutes from the femoral access vs 358 minutes of digital subtraction angiography radiation from the brachial access. Conclusion: The operator dose rates were correlated to patient dose rate; however, C-arm angulation and changing from femoral to brachial vascular access site may disproportionally increase the operator radiation risk compared with the patient radiation risk. An instant risk chart may improve operator dose awareness during EVAR.


2019 ◽  
Vol 187 (1) ◽  
pp. 21-27 ◽  
Author(s):  
Laurent Faroux ◽  
Thierry Blanpain ◽  
Anthony Fernandez ◽  
Pierre Nazeyrollas ◽  
Sophie Tassan-Mangina ◽  
...  

ABSTRACT Interventional cardiologists count among the health professionals that are most exposed to ionising radiation. To minimise exposure, it is recommended that the patient be placed at the maximum distance possible from the X-ray source, but this recommendation has not been clinically validated. We aimed to investigate the impact of the average table height on the level of radiation delivered to cardiologists performing coronary interventions. The population for analysis included all invasive coronary procedures performed in our centre from March to June 2017. The primary endpoint was operator radiation exposure, as assessed using personal electronic dosimeters located on the operator’s left arm. In total, 225 invasive coronary procedures were analysed. When the average table height was 1126 mm or more, the operators received a radiation dose that was, on average, 53% lower than when the table was lower than 1126 mm. This reduction remained significant by multivariate analysis adjusted for the operator.


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