scholarly journals Effective dose in medicine

2020 ◽  
Vol 49 (1_suppl) ◽  
pp. 126-140
Author(s):  
C.J. Martin

The International Commission on Radiological Protection (ICRP) developed effective dose as a quantity related to risk for occupational and public exposure. There was a need for a similar dose quantity linked to risk for making everyday decisions relating to medical procedures. Coefficients were developed to enable the calculation of doses to organs and tissues, and effective doses for procedures in nuclear medicine and radiology during the 1980s and 1990s. Effective dose has provided a valuable tool that is now used in the establishment of guidelines for patient referral and justification of procedures, choice of appropriate imaging techniques, and providing dose data on potential exposure of volunteers for research studies, all of which require the benefits from the procedure to be weighed against the risks. However, the approximations made in the derivation of effective dose are often forgotten, and the uncertainties in calculations of risks are discussed. An ICRP report on protection dose quantities has been prepared that provides more information on the application of effective dose, and concludes that effective dose can be used as an approximate measure of possible risk. A discussion of the way in which it should be used is given here, with applications for which it is considered suitable. Approaches to the evaluation of risk and methods for conveying information on risk are also discussed.

2020 ◽  
Vol 189 (3) ◽  
pp. 318-322
Author(s):  
Ritva Bly ◽  
Hannu Järvinen ◽  
Sampsa Kaijaluoto ◽  
Verneri Ruonala

Abstract Contemporary collective effective doses to the population from x-ray and nuclear medicine examinations in Finland in 2018 was estimated. The estimated effective dose per caput from x-ray examinations increased from year 2008 to 2018 respectively from 0.45 mSv to 0.72 mSv and from nuclear medicine examinations from 0.03 mSv to 0.04 mSv. The proportional dose due to CT examinations of the total collective effective dose from all x-ray examinations increased from 58% in 2008 to 70% in 2018 and the dose did not change substantially in total when new conversion factors were applied. The collective effective dose from conventional plain radiography did not change substantially during the last ten years while the new (ICRP 103) tissue weighting factors were taken into use in 2018, however frequencies of examinations in total decreased. The collective effective dose from CT in nuclear medicine tripled between 2009 and 2018.


2020 ◽  
Vol 191 (2) ◽  
pp. 188-191
Author(s):  
Petr P S Otahal ◽  
Ivo Burian ◽  
Eliska Fialova ◽  
Josef Vosahlik

Abstract Measurements of activity concentration of radon gas and radon decay products were carried out in several workplaces including schools, radium spas, swimming pools, water treatment plants, caves and former mines. Based on these measurements, annual effective doses to workers were estimated and values of the equilibrium factor, F, were calculated. This paper describes the different approaches used to estimate the annual effective dose based on the dose coefficients recommended by the International Commission on Radiological Protection. Using the measured F values as opposed to the default F value of 0.4 changed the doses by about 5–95% depending mainly upon the ventilation conditions of the workplace.


Author(s):  
J. Bazoma ◽  
G. B. Dallou ◽  
P. Ondo Meye ◽  
C. Bouka Biona ◽  
Saïdou ◽  
...  

The present study aimed at estimating organ and effective doses from computed tomography (CT) scans of paediatric patients in three hospitals in Brazzaville, Congo Republic. A total of 136 data on paediatric patients, from 0.25 (3 months) to 15 years old, who underwent head, chest, abdomen – pelvis (AP) and chest – abdomen – pelvis (CAP) CT scans was considered. The approach followed in the present study to compute organ doses was to use pre-calculated volume CT dose index (CTDIvol) – and 100 milliampere-second (mAs) – normalized organ doses determined by Monte Carlo (MC) simulation. Effective dose were then derived using the international commission on radiological protection (ICRP) publications 60 and 103 formalism. For comparison purposes, effective dose were also computed using dose-length product (DLP) – to – effective dose conversion factors. A relatively high variation in organ and effective doses was observed in each age group due to the dependence of patient dose on the practice of technicians who perform the CT scan within the same facility or from one facility to another, patient size and lack of adequate training of technicians. In the particular case of head scan, the brain and the eye lens were delivered maximum absorbed doses of 991.81 mGy and 1176.51 mGy, respectively (age group 10-15 y). The maximum absorbed dose determined for the red bone marrow was 246.08 mGy (age group 1-5 y). This is of concern as leukaemia and brain tumours are the most common childhood cancers and as the ICRP recommended absorbed dose threshold for induction of cataract is largely exceeded. Effective doses derived from MC calculations and ICRP publications 60 and 103 tissues weighting factors showed a 0.40-17.61 % difference while the difference between effective doses derived by the use of k- factors and those obtained by MC calculations ranges from 0.06 to 224.87 %. The study has shown that urgent steps should be taken in order to significantly reduce doses to paediatric patients to levels observed in countries where dose reduction techniques are successfully applied.


2016 ◽  
Vol 21 (4) ◽  
pp. 66-72 ◽  
Author(s):  
Lillian Atsumi Simabuguro Chinem ◽  
Beatriz de Souza Vilella ◽  
Cláudia Lúcia de Pinho Maurício ◽  
Lucia Viviana Canevaro ◽  
Luiz Fernando Deluiz ◽  
...  

ABSTRACT Objective: The aim of this study was to compare the equivalent and effective doses of different digital radiographic methods (panoramic, lateral cephalometric and periapical) with cone-beam computed tomography (CBCT). Methods: Precalibrated thermoluminescent dosimeters were placed at 24 locations in an anthropomorphic phantom (Alderson Rando Phantom, Alderson Research Laboratories, New York, NY, USA), representing a medium sized adult. The following devices were tested: Heliodent Plus (Sirona Dental Systems, Bernsheim, Germany), Orthophos XG 5 (Sirona Dental Systems, Bernsheim, Germany) and i-CAT (Imaging Sciences International, Hatfield, PA, USA). The equivalent doses and effective doses were calculated considering the recommendations of the International Commission of Radiological Protection (ICRP) issued in 1990 and 2007. Results: Although the effective dose of the radiographic set corresponded to 17.5% (ICRP 1990) and 47.2% (ICRP 2007) of the CBCT dose, the equivalent doses of skin, bone surface and muscle obtained by the radiographic set were higher when compared to CBCT. However, in some areas, the radiation produced by the orthodontic set was higher due to the complete periapical examination. Conclusion: Considering the optimization principle of radiation protection, i-CAT tomography should be used only in specific and justified circumstances. Additionally, following the ALARA principle, single periapical radiographies covering restricted areas are more suitable than the complete periapical examination.


2021 ◽  
pp. 039156032199444
Author(s):  
Bob Yang ◽  
Noorunisa Suhail ◽  
Johan Marais ◽  
James Brewin

Background: Urolithiasis patients often require frequent urinary tract imaging, leading to high radiation exposure. CT Kidney-Ureter-Bladder (CT-KUB) is the gold standard in urolithiasis detection, however it is thought to harbour significant radiation load. Urologists have therefore utilised abdominal radiographs (XR-KUB) as an alternative, though with markedly lower sensitivity and specificity. We present the first contemporary UK study comparing the effective doses of XR-KUBs with low dose CT-KUBs. Method: Fifty-three patients were retrospectively identified in a single centre who underwent both a XR-KUB and a CT-KUB in 2018. Effective-Dose was measured by converting the recorded ‘Dose Area/Length Product’ via the International Commission on Radiological Protection formula. Results: The average effective dose of XR-KUBs and low dose CT-KUBs were 5.10 mSv and 5.31 mSv respectively. Thirty-four percent (18/53) of patients had a XR-KUBs with a higher effective dose than their low dose CT-KUB. Patients with higher Weight, BMI and AP diameter had higher effective doses for both their XR and low dose CT-KUBs. All patients in our study weighing over 92 kg or with a BMI greater than 32 had a XR-KUBs with a higher effective dose than their low dose CT-KUB. Conclusion: This data supports moving away from XR-KUBs for the investigation of urolithiasis, particularly in patients with a high BMI.


2006 ◽  
Vol 45 (01) ◽  
pp. 1-9 ◽  
Author(s):  
D. Noßke ◽  
P. Schnell-Inderst ◽  
M. Hacker ◽  
K. Hahn ◽  
G. Brix ◽  
...  

Summary Aim: Man-made radiation exposure to the German population predominantly results from the medical use of ionizing radiation. It was therefore the aim of the present study, to provide public health information concerning diagnostic nuclear medicine procedures carried out in Germany between 1996 and 2002. Material and methods: Application frequencies for 10 groups of procedures were estimated from official reimbursement data provided by the German health insurance companies. Mean effective doses for these examinations were estimated from data provided by 14 clinics and 10 practices concerning the radiopharmaceuticals in use and the activities administered. Results: During the period 1996-2002, a total of (3.83 ± 0.31) million nuclear medicine procedures were performed in average per year, which corresponds to a mean annual application frequency of approximately 47 examinations per 1 000 inhabitants. More than 90% of the examinations were scintigraphies of the thyroid (37%), skeleton (25%), myocardium (13%), lungs (8%) and kidneys (8%). The averaged collective effective dose was (10.2 ± 1.4) ⋅103 manSv per year, which corresponds to a mean annual per caput effective dose of about (0.12 ± 0.02) mSv. Three types of procedures were responsible for about 80% of the total collective effective dose: scintigraphies of the myocardium (36%), skeleton (33%) and thyroid (10%). Averaged over all procedures carried-out, the mean effective dose per examination was (2.7 ± 0.8) mSv. Conclusion: The average effective dose per inhabitant and year caused by nuclear medicine examinations is markedly lower than that resulting from medical X-ray procedures (0.12 vs. 1.8 mSv). Reduction of patient exposure may be achieved, for example, by replacing 201Tl-labeled radiopharmaceuticals by 99mTc-labeled compounds.


2020 ◽  
Vol 68 (2) ◽  
pp. 161-165
Author(s):  
Yeasin Noor ◽  
Jannatul Ferdous ◽  
Naureen Ahsan ◽  
Abdus Sattar Mollah

This study estimates the potential health risks attributed to the internal contamination of occupational workers at the Institute of Nuclear Medicine and Allied Sciences (INMAS) located at Dhaka Medical College and Hospital, Dhaka, during nuclear medicine practices involving the radionuclides 131I and 99mTc, using in vitro methods from urine samples. A total of 55 urine samples from 6 occupational workers are collected over a period of about 11 months. These samples are analyzed using a High Purity Germanium (HPGe) detector coupled with a multichannel analyzer (MCA). The radioactivity of the isotopes present in each urine sample is measured based on the detector efficiency, and the committed effective dose due to each intake is calculated from this activity. The average annual doses of individual workers found in this study range from 4.57 × 10-5 mSv to 9.72 × 10-3 mSv. Although these doses are considerably below the International Commission on Radiological Protection (ICRP) recommended annual dose limit of 20 mSv, efforts to abide by the ALARA principle should continue. Dhaka Univ. J. Sci. 68(2): 161-165, 2020 (July)


2020 ◽  
Vol 9 (3) ◽  
pp. 121-123
Author(s):  
Ilham Khalid Ibrahim ◽  
Fatiheea Fatihalla Hassan ◽  
Nashwan Karkhi Abdulkareem

Background: In conventional X-ray examinations, patients are exposed to radiation. Biological hazards from radiation of any source is expressed as effective dose, and is measured in millisieverts (mSv). The purpose of this study was to assess and calculate the effective dose values for patients undergoing posteroanterior (PA) chest, abdomen, anteroposterior (AP) pelvis, and cervical spine X-ray examinations in general hospitals of Erbil city and compare it with those of other studies. Materials and Methods: A total of 255 patients between 20-70 years of age participated in this work (85 per hospital). The patients’ characteristics included age, sex, examination type, projection posture, and exposure parameters captured by NOMEX Multimeter including tube potential and current-time product. The mean effective doses (EDs) of four different examinations (chest (PA), pelvis (AP), abdomen, and cervical spine) were measured using the Monte Carlo method and compared with those of other studies. Results: The mean EDs were calculated 1.04, 2.01, 3.12, and 3.22 mSv for chest (PA), pelvis (AP), abdomen, and cervical spine, respectively. All ED values in this study were higher than those of published studies. The aim of the study was to increase the awareness of the radiographer and patients undergoing conventional X-ray diagnostic radiology on the risk of ionizing radiation for radiological protection in Erbil hospitals. Conclusion: The mean EDs were increased by an increase in the age; this may increase the probability of cancer incidence and heritable diseases. Hence, dose optimization is required due to more probable incidence of cancer when compared to other studies.


2008 ◽  
Vol 51 (spe) ◽  
pp. 103-107 ◽  
Author(s):  
Bernardo Maranhão Dantas ◽  
Eder Augusto de Lucena ◽  
Ana Letícia Almeida Dantas

The manipulation of unsealed sources in nuclear medicine poses significant risks of internal exposure to the staff. According to the International Atomic Energy Agency, the radiological protection program should include an evaluation of such risks and an individual monitoring plan, assuring acceptable radiological safety conditions in the workplace. The IAEA Safety Guide RS-G-1.2 recommends that occupational monitoring should be implemented whenever it is likely that committed effective doses from annual intakes of radionuclides would exceed 1 mSv. It also suggests a mathematical criterion to determine the need to implement internal monitoring. This paper presents a simulation of the IAEA criteria applied to commonly used radionuclides in nuclear medicine, taking into consideration usual manipulated activities and handling conditions. It is concluded that the manipulation of 131I for therapy presents the higher risk of internal exposure to the workers, requiring the implementation of an internal monitoring program by the Nuclear Medicine Centers.


2004 ◽  
Vol 43 (03) ◽  
pp. 79-84 ◽  
Author(s):  
V. Minkov ◽  
G. Brix ◽  
D. Noßke

SummaryDiagnostic reference levels (DRL) were introduced in Germany by a publication in the Bundesanzeiger Nr. 143 from August 5, 2003. Thereby a recommendation of the International Commission on Radiological Protection (ICRP) from 1996 and a demand by the EU Guideline 97/43/EURATOM from 1997 is converted into national law. Aim of this paper is to acquaint with and to justify the determined DRL as well as to provide information on the practical use of the concept of the DRL. Material and method: DRL were established by experts on the basis of a national survey conducted in hospitals and private practices as well as of national and international recommendations and published by the Federal Office for Radiation Protection. Besides the data basis the dosimetric principles are described for the estimation of the effective doses of the various examinations. Results: DRL were established for 10 frequent and dose-relevant examinations constituting more than 80% of all nuclear medicine examinations currently performed in Germany. For some examinations two different DRL were given to take into account clinical conditions. For paediatric examinations fractions of the activities to be administered to adults are given dependent on the body weight. Discussion: The published DRL are in agreement with the majority of national and international recommendations and with the present practice of nuclear medicine examinations in Germany. They are related to average activities for groups of patients with standard sizes and, moreover, to typical examinations with current standard equipment. It is planned to check and to reconsider the DRL about every 2-3 years.


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