Effective dose: a radiation protection quantity

2012 ◽  
Vol 41 (3-4) ◽  
pp. 117-123 ◽  
Author(s):  
H-G. Menzel ◽  
J. Harrison
Keyword(s):  
Effective Dose ◽  
Radiation Protection ◽  
Scientific Information ◽  
Scientific Data ◽  
Whole Body ◽  
Practical Implementation ◽  
Radiological Protection ◽  
Stochastic Effects ◽  
Weighting Factors ◽  
Dose Limits

Modern radiation protection is based on the principles of justification, limitation, and optimisation. Assessment of radiation risks for individuals or groups of individuals is, however, not a primary objective of radiological protection. The implementation of the principles of limitation and optimisation requires an appropriate quantification of radiation exposure. The International Commission on Radiological Protection (ICRP) has introduced effective dose as the principal radiological protection quantity to be used for setting and controlling dose limits for stochastic effects in the regulatory context, and for the practical implementation of the optimisation principle. Effective dose is the tissue weighted sum of radiation weighted organ and tissue doses of a reference person from exposure to external irradiations and internal emitters. The specific normalised values of tissue weighting factors are defined by ICRP for individual tissues, and used as an approximate age- and sex-averaged representation of the relative contribution of each tissue to the radiation detriment of stochastic effects from whole-body low-linear energy transfer irradiations. The rounded values of tissue and radiation weighting factors are chosen by ICRP on the basis of available scientific data from radiation epidemiology and radiation biology, and they are therefore subject to adjustment as new scientific information becomes available. Effective dose is a single, risk-related dosimetric quantity, used prospectively for planning and optimisation purposes, and retrospectively for demonstrating compliance with dose limits and constraints. In practical radiation protection, it has proven to be extremely useful.

Reference levels in the context of Fukushima - lessons learned and a challenge for the radiation protection system

2012 ◽  
Vol 41 (3-4) ◽  
pp. 282-285 ◽  
Author(s):  
K. Sakai
Keyword(s):  
Radiation Protection ◽  
School Children ◽  
General Public ◽  
Radiation Effects ◽  
Scientific Information ◽  
Lessons Learned ◽  
Protection System ◽  
Reference Level ◽  
Radiological Protection ◽  
Plain Language

A number of dose criteria were set after the accident in Fukushima, including a criterion regarding the use of school playgrounds in Fukushima. Considering the band of 1–20 mSv/year recommended by the International Commission on Radiological Protection (ICRP) for public exposure under existing exposure situations, Japanese authorities set 20 mSv/year as a ‘start line’ for reducing the dose to school children. However, this led to considerable confusion among the general public and some experts. They thought that the dose limit was increased to 20 mSv/year (20 times as high as before), and that school children could be exposed to 20 mSv in 1 year. This is just an example of confusion caused by inadequate comprehension of radiation effects, misunderstanding of radiation protection concepts, or both. Another issue was raised regarding the higher radiosensitivity of children compared with adults. In the 2007 ICRP Recommendations, a higher risk coefficient is given to the whole population than the adult population, because the whole population includes children; a subpopulation with higher radiosensitivity and a longer life span. The point of argument was whether a lower reference level should be set for children alone. Radiation protection experts should continue to collect scientific information to improve the radiation protection system. In addition, it is the role of these experts to explain the framework of radiation protection to the general public in plain language.

Effective dose from inhaled radon and its progeny

2012 ◽  
Vol 41 (3-4) ◽  
pp. 378-388 ◽  
Author(s):  
J.D. Harrison ◽  
J.W. Marsh
Keyword(s):  
Effective Dose ◽  
Reference Conditions ◽  
International Commission ◽  
Radiological Protection ◽  
Dose Calculations ◽  
Reference Levels ◽  
Weighting Factors ◽  
Preliminary Results ◽  
Recent Statement ◽  
Dose Coefficients

Currently, the International Commission on Radiological Protection (ICRP) uses the dose conversion convention to calculate effective dose per unit exposure to radon and its progeny. In a recent statement, ICRP indicated the intention that, in future, the same approach will be applied to intakes of radon and its progeny as is applied to all other radionuclides, calculating effective dose using reference biokinetic and dosimetric models, and radiation and tissue weighting factors. Effective dose coefficients will be given for reference conditions of exposure. In this paper, preliminary results of dose calculations for Rn-222 progeny are presented and compared with values obtained using the dose conversion convention. Implications for the setting of reference levels are also discussed.

A regulatory perspective on whether the system of radiation protection is fit for purpose

2012 ◽  
Vol 41 (3-4) ◽  
pp. 57-63 ◽  
Author(s):  
M.A. Boyd
Keyword(s):  
Effective Dose ◽  
Radiation Protection ◽  
Organ Dose ◽  
Radiological Protection ◽  
X Rays ◽  
Tolerance Dose ◽  
Critical Organ ◽  
Fit For Purpose ◽  
And Gender ◽  
Definition Of

The system of radiation protection has its origins in the early efforts to protect people from x rays and radium. It was at the Second International Congress of Radiology in Stockholm in 1928 where the first radiation protection recommendations were adopted. The system of protection steadily evolved as new sources of exposure arose and understanding of radiation-related health risks improved. Safeguarding against these risks has required regulators to set enforceable (i.e. measurable) standards. From erythema dose to tolerance dose, critical organ dose to effective dose equivalent, and now effective dose, the units used to set these limits have evolved along with the science underpinning them. Similarly, the definition of the person or group being protected has changed - from Standard Man to Reference Man to Reference Person, with age and gender differences now considered explicitly. As regulators look towards implementing the changes in the 2007 Recommendations of the International Commission on Radiological Protection (ICRP), there remain questions about how to translate an optimisation-based system of constraints and reference levels into the more familiar regime of enforceable limits. Nevertheless, as the new ICRP Recommendations are refinements of a system that did the job it was designed to do more than adequately, so too will the new system of radiation protection be fit for purpose.

US NRC discussion of options to revise radiation protection recommendations

2012 ◽  
Vol 41 (3-4) ◽  
pp. 313-317
Author(s):  
D.A. Cool
Keyword(s):  
Radiation Protection ◽  
Nuclear Regulatory Commission ◽  
Radiological Protection ◽  
Policy Paper ◽  
Occupational Dose ◽  
Wide Range ◽  
Other Information ◽  
Dose Limits ◽  
Key Issues ◽  
Regulatory Commission

The Nuclear Regulatory Commission (NRC) is continuing the process of engaging stakeholders on issues associated with possible changes to the radiation protection regulations contained in 10 CFR Part 20, and other parts of the NRC regulations, to increase alignment with international recommendations. The Commission is particularly seeking to explore implications, as appropriate and where scientifically justified, of greater alignment with the 2007 Recommendations of the International Commission for Radiological Protection. Other information from national and international sources is also being considered. Given that the NRC regulations provide adequate protection, the discussion has been focusing on discerning the benefits and burdens associated with revising the radiation protection regulatory framework. NRC, through three Federal Register Notices, has officially solicited comments on a series of key issues, and has conducted a series of facilitated workshops to encourage feedback from a wide range of stakeholders. The issues include the use of updated scientific methodologies and terminology, the occupational dose limits, and the use of the concepts of constraints in optimisation. NRC staff provided a policy paper with recommendations to the Commission on April 25, 2012 (NRC, 2012).

Radiation exposure of patients undergoing whole-body FDG-PET/CT examinations

2014 ◽  
Vol 53 (05) ◽  
pp. 217-220 ◽  
Author(s):  
D. Noßke ◽  
U. Leche ◽  
G. Brix
Keyword(s):  
Radiation Exposure ◽  
Effective Dose ◽  
Fdg Pet ◽  
Radiation Risk ◽  
Whole Body ◽  
Organ Doses ◽  
Weighting Factors ◽  
Pet Ct ◽  
Conversion Coefficients ◽  
Fdg Pet Ct

SummaryAim: Reinvestigation of the radiation exposure of patients undergoing whole-body [18F]FDG-PET/CT examinations pursuant to the revised recommendations of the ICRP. Methods: Conversion coefficients for equivalent organ doses were determined for realistic anthropomorphic phantoms of reference persons. Based on these data, conversion coefficients for the effective dose were calculated using the revised tissue-weighting factors that account for the different radiation susceptibilities of organs and tissues, and the redefinition of the group ‘remainder tissues’. Results: Despite the markedly changed values of the equivalent organ doses estimated for FDG and of the tissue-weighting factors, the conversion coefficient for the effective dose resulting from FDG administration decreases only slightly by 10 %. For whole-body CT scans it remains even unchanged. Conclusion: The updated dose coefficients provide a valuable tool to easily assess the generic radiation risk of patients undergoing whole- body PET/CT (or PET/MRI) examinations and can be used, amongst others, for protocol optimization.

Radiation Safety

2018 ◽  
Author(s):  
Erin M. Maddy ◽  
Kevin Abnet ◽  
Geoffrey Scriver ◽  
Mrinal Shukla
Keyword(s):  
Best Practices ◽  
Radiation Protection ◽  
Human Body ◽  
Radiation Safety ◽  
Radiological Protection ◽  
Surgical Practice ◽  
Anesthesia Practice ◽  
Dose Limits ◽  
Effects Of Radiation

Exposure to ionizing radiation is increasing in modern anesthesia practice, due to both the number of procedures facilitated and the expanding role of imaging in surgical practice. International Commission on Radiological Protection (ICRP) recommends that physicians who assist with radiation procedures be educated on the basics of radiation including units, effects of radiation exposure, and radiation protection for both providers and patients. This chapter will mirror the recommendations of the ICRP and include an introduction to radiation production, terminology, units, effects on the human body, dose limits, best practices for radiation protection, and safety infrastructure.

scholarly journals The importance of protection glasses during neuroangiographies: A study on radiation exposure at the lens of the primary operator

2016 ◽  
Vol 22 (3) ◽  
pp. 368-371 ◽  
Author(s):  
JB Tavares ◽  
E Sacadura-Leite ◽  
T Matoso ◽  
LL Neto ◽  
L Biscoito ◽  
...  
Keyword(s):  
Radiation Dose ◽  
Radiation Protection ◽  
Interventional Neuroradiology ◽  
Diagnostic Procedures ◽  
Threshold Limit Value ◽  
Whole Body ◽  
Radiological Protection ◽  
Specific Information ◽  
Radiation Beam ◽  
Primary Operator

Background In interventional neuroradiology, few operators routinely use radiation protection glasses. Moreover, in most centers, radiation dose data only accounts for whole body dose without specific information on lens dose. In 2012, the International Commission on Radiological Protection advised that the threshold limit value for the lens should be 20 mSv/year instead of the previous 150 mSv/year limit. The purpose of this study was to compare the radiation dose in the operator’s lens during real diagnostic and interventional neuroangiographies, either using or without lead protection glasses. Methods Using the Educational Direct Dosimeter (EDD30 dosimeter), accumulated radiation dose in the lens was measured in 13 neuroangiographies: seven diagnostic and six interventional. Operators with and without radiation protection glasses were included and the sensor was placed near their left eye, closest to the radiation beam. Results Without glasses, the corrected mean dose of radiation in the lens was 8.02 µSv for diagnostic procedures and 168.57 µSv for interventional procedures. Using glasses, these values were reduced to 1.74 µSv and 33.24 µSv, respectively. Conclusion Considering 20 mSv as the suggested annual limit of equivalent dose in the lens, neuroradiologists may perform up to 2,494 diagnostic procedures per year without protecting glasses, a number that increases to 11,494 when glasses are used consistently. Regarding intervention, a maximum of 119 procedures per year is advised if glasses are not used, whereas up to 602 procedures/year may be performed using this protection. Therefore, neuroradiologists should always wear radiation protection glasses.

scholarly journals Investigation of 18F and 89Zr Isotopes Self-Absorption and Dose Rate Parameters for PET Imaging

Dose-Response ◽  
2021 ◽  
Vol 19 (3) ◽  
pp. 155932582110284
Author(s):  
Abdulrahman A. Alfuraih ◽  
Khalid Alzimami ◽  
Andy K. Ma
Keyword(s):  
Effective Dose ◽  
Dose Rate ◽  
Radiation Protection ◽  
Rate Constants ◽  
International Committee ◽  
National Standards ◽  
Radiological Protection ◽  
Positron Emission ◽  
American Nuclear Society ◽  
Conversion Coefficients

This work concerns study of self-absorption factor (SAF) and dose rate constants of zirconium-89 (89Zr) for the purpose of radiation protection in positron emission tomography (PET) and to compare them with those of 18F-deoxyglucose (18F-FDG). We analyzed the emitted energy spectra by 18F and 89Zr through anthropomorphic phantom and calculated the absorbed energy using Monte Carlo method. The dose rate constants for both radionuclides were estimated with 2 different fluence-to-effective dose conversion coefficients. Our estimated SAF value of 0.65 for 18F agreed with the recommendation of the American Association of Physicists in Medicine (AAPM). The SAF for 89Zr was in the range of 0.61-0.66 depending on the biodistribution. Using the fluence-to-effective dose conversion coefficients recommended jointly by the American National Standards Institute and the American Nuclear Society (ANSI/ANS), the dose rate at 1 m from the patient for 18F was 0.143 μSv·MBq−1·hr−1, which is consistent with the AAPM recommendation, while that for 89Zr was 0.154 μSv·MBq−1·hr−1. With the conversion coefficients currently recommended by the International Committee on Radiological Protection (ICRP), the dose rate estimates were lowered by 2.8% and 2.6% for 89Zr and 18F, respectively. Also, we observed that the AAPM derived dose is an overestimation near the patient, compared to our simulations, which can be explained by the biodistribution nature and the assumption of the point source. Thus, we proposed new radiation protection factors for 89Zr radionuclide.

Radioiodine treatment of feline hyperthyroidism in Germany

2002 ◽  
Vol 41 (06) ◽  
pp. 245-251 ◽  
Author(s):  
M. Knietsch ◽  
T. Spillmann ◽  
E.-G. Grünbaum ◽  
R. Bauer ◽  
M. Puille
Keyword(s):  
Radiation Exposure ◽  
Radiation Protection ◽  
Thyroid Function ◽  
Radioiodine Therapy ◽  
Whole Body ◽  
Radioiodine Treatment ◽  
Normal Thyroid ◽  
Normal Thyroid Function ◽  
Body Activity ◽  
Thyroid Uptake

SummaryAim: Establishment of radioiodine treatment of feline hyperthyroidism in veterinary routine in accordance with German radiation protection regulations. Patients and methods: 35 cats with proven hyperthyroidism were treated with 131I in a special ward. Thyroid uptake and effective halflife were determined using gammacamera dosimetry. Patients were released when measured whole body activity was below the limit defined in the German “Strahlenschutzverordnung”. Results: 17/20 cats treated with 150 MBq radioiodine and 15/15 cats treated with 250 MBq had normal thyroid function after therapy, normal values for FT3 and FT4 were reached after two and normal TSH levels after three weeks. In 14 cats normal thyroid function was confirmed by controls 3-6 months later. Thyroidal iodine uptake was 24 ± 10%, effective halflife 2.5 ± 0.7 days. Whole body activity <1 MBq was reached 13 ± 4 days after application of 131I. Radiation exposure of cat owners was estimated as 1.97 Sv/MBq for adults. Conclusion: Radioiodine therapy of feline hyper-thyroidism is highly effective and safe. It can easily be performed in accordance with German radiation protection regulations, although this requires hospitalisation for approximately two weeks. Practical considerations on radiation exposure of cat owners do not justify this long interval. Regulations for the veterinary use of radioactive substances similar to existing regulations for medical use in humans are higly desirable.

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