ICRP 103 PDF
ICRP Publication The Recommendations of the. International Commission on. Radiological Protection. The full report is available for download and. Download free PDF Other Resources. Free Extract of ICRP Publication · ICRP Publication summary article from the Journal of Radiological Protection . The International Commission on Radiological Protection (ICRP) is the primary body in (yazik.info
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yazik.info ICRP Ny basisrekommendasjon fra den internasjonale strålevernskommisjonen. Tor Wøhni. Gardermoen 17 november The International Commission on Radiological Protection (ICRP) is the primary body in protection against ionising radiation. ICRP is a registered charity and is. The Recommendations of ICRP. Dr Jack Valentin, Scientific Secretary, ICRP. ○ International Commission on Radiological Protection. ICRP: Who, why.
The International Commission on Radiological Protection ICRP Committee-I reviewed the information related to radiogenic cataracts just before issuing the general recommendations ICRP [ 1 ] and realized the fact that the eye lens is more sensitive than previously assumed. This was based on the studies of children treated for hemangioma and review of the atomic-bomb A-bomb survivor data.
Recently, the ICRP[ 4 , 5 ] issued revised recommendations reducing the equivalent dose limits to the eye lens. The Atomic Energy Regulatory Board of India has initiated a series of measures to develop protection devices for reducing exposure to the eye lens, for radiation monitoring, to sensitize the critical groups involved in cine fluoroscopy-guided procedures, and evolve specialized training programs for those who have the potential to receive significant lens doses.
Some of the information relevant to this decision is outlined below. Cataract is an eye disease characterized by the opacity of the lens which under normal conditions focuses the image on the retina to enable perception of the visual information.
Such opacity may lead to just reduction in the vision, partial impairment of vision, or total blindness. Cataract is the single-most important cause of blindness in human beings. Depending on the nature and location, cataracts are classified as posterior subcapsular PSC , cortical, and nuclear.
ICRP publication now available in French
Neutrons are several folds more efficient than photons in inducing cataracts. At present, it is clear that a number of factors such as age, sex, hereditary factors, duration of exposure, blood sugar level diabetes , blood pressure and cardiovascular diseases, alcohol consumption, smoking, exposure to sunlight, ultraviolet-B and infrared radiations, and use of corticosteroids may influence the formation of cataracts.
A number of factors[ 8 , 9 ] related to the mode of exposure such as dose rate, radiation quality, scoring systems used, variable latent periods, lack of clarity pertaining to the mechanism of induction, and the aforesaid confounders have created considerable uncertainty in the assessment of threshold dose for the induction of cataract.
The mechanism of formation of radiation-induced cataracts remains unclear. Radiation may disturb a number of physiological processes such as the formation of transparent lens fibers by differentiation of epithelial cells, reduction in the repair enzymes, hampering of the mechanism of replacement of damaged fibers, and damage to the lens cell membrane. Radiation can also inflict oxidative damage to lens fiber proteins by the radiation-induced free radicals and cause DNA damage resulting in opacity at a later stage.
Since then a considerable amount of data has accrued for acute as well as protracted exposures. Epidemiological studies for acute exposures include revised A-bomb survivor data[ 3 , 11 , 12 ] and Chernobyl liquidators. The epidemiological studies include prospective cohort studies, retrospective case-control studies, and cross-sectional studies.
However, many uncertainties in the studies fail to provide a clear indication of a threshold dose. Exposure at low doses and lower dose rates may have long latent periods of several decades.
Most of the studies use different systems. These may subsequently progress to vision-impairing cataracts. The Lens Opacity Classification System[ 15 ] uses reference slides classification based on nuclear color and opalescence, posterior and subcapsular cataracts into 5—6 grades.
This system appears appropriate for scoring radiation cataract. Reanalysis of the A-bomb survivors related to the risk of cataracts by a number of researchers[ 3 , 11 , 12 , 20 , 21 ] suggests a relative risk of 1.
Group dosimetry, dose calculation techniques, thermoluminescent, and electron spin resonance dosimetry techniques based on tooth enamel were used for assessment of individual doses. Based on the Merriam-Focht scoring system, the study suggests a threshold dose in the range of 0. Even though there is a possibility of a threshold of mSv, it cannot be confirmed due to uncertainty in the mechanisms involved in induction.
Lower doses and protracted exposures are associated with longer latent periods, thus resulting in the overestimation of a threshold dose. Those engaged in cine-fluoroscopy-guided interventional procedures such as hepatic chemoembolization, catheterization, endoscopic retrograde cholangiopancreatography, and gastroenterologists receive doses ranging from 0. Astronauts, airline pilots, residents in contaminated buildings, and radium dial painters also showed elevated risk.
In Annex A of its report 27 , the United Nations Scientific Committee on the Effects of Atomic Radiation pointed out the numerous difficulties in obtaining reliable estimates of absorbed doses and consequently the effective doses corresponding to clinical examinations, noting that this quantity should always be correlated with homogeneous populations.
That report highlighted three major approaches to estimating doses in patients undergoing radiological procedures: dose measurements directly in the patient; dose measurements in physical phantoms and Monte Carlo calculations. In each case, the associated uncertainties 28 and difficulties were highlighted, as was the weak association that these results can have with estimates of risk or detriment. McCollough et al. The authors began by addressing the scenario in which a patient, after undergoing an examination, asks the doctor: "What dose did I receive?
The authors assert that what the patient really wants to know is how much risk is associated with the procedure performed.
In addition, other medical professionals now have more access to information available in medical journals about the risk of stochastic effects resulting from procedures such as CT Taking into account the limitations and uncertainties associated with the use of the effective dose to support the determination of risks from radiological procedures, McCollough et al.
The authors stated that the effective dose could be applied as a kind of "whole-body dose equivalent" value related to the risks arising from non-uniform irradiation in different diagnostic modalities. With this approach, it is possible to compare different dose values resulting from different imaging modalities with similar purposes, such as conventional coronary angiography, CT angiography and myocardial perfusion with nuclear medicine.
Excluding differences related to gender and age, equal effective doses correspond to approximately the same overall risk. For uniform whole-body exposure, even for a specific type of radiation, the effective dose is equal to the absorbed dose of radiation multiplied by the radiation weighting factor. ICRP Publication states that the effective dose is calculated for a reference person and not for an individual. In addition, ICRP Publication 30 clarifies that the factors used to weight the absorbed doses to specific tissues do not vary with age or gender, and that the use of the weighted sum for obtaining the effective dose is not applicable to a specific individual.
Therefore, the effective dose serves to support regulatory devices and comparative assessments of professional practices. It should be noted that effective dose was established as a quantity applicable to planned situations.
ICRP Publication 33 states that the distribution of ages of workers and the general population can be significantly different from that of a population subjected to a given type of medical procedure that employs ionizing radiation. Other aspects, such as the gender of the patients undergoing the procedure, can be related to these age distributions, which are used in deriving the value of the effective dose.
However, the convenience of using quantitative parameters that describe a procedure in terms of its potential risk to the health of patients, compared with the alternative practices or the application of a new technique in contrast with others currently in use, makes it a tempting option.
For such correlations associated with the CT technique, Dixon 34 emphasized the need to train all of the workers involved, which comprises adapting the instruction of medical students, technicians, technologists, and physicians of other specialties to include concepts regarding doses and their implications.
The author also highlighted the apparent inconsistency of institutions that invest hundreds of thousands of dollars, euros, or Brazilian reals in the acquisition of a new CT modality but are reluctant to invest in training their staff, in the continuing education of their physicians, or in obtaining the support of medical physics professionals for the proper monitoring of aspects related to the dose in CT and in other modalities.
This quantity can be used in order to compare the relative detriments of radiological procedures and other radiation sources when calculated for populations of patients that are homogeneous in terms of age and gender. The use of effective dose can also be useful for the purpose of comparisons between different procedures and techniques, or between different hospitals or countries provided that the reference patient or patient population are similar with respect to age and gender.
It should be borne in mind that the ICRP does not recommend using effective dose to estimate the risk for an individual subjected to a diagnostic imaging procedure.
Impact of updating the non-radiation parameters in the ICRP detriment model
That is because the quantity was introduced as a means of representing the potential stochastic detriments resulting from the exposure of populations of workers and the general population. Therefore, it is incorrect to use effective dose as an estimator of individual risks for patients undergoing radio-logic studies. In summary, the effective dose can be useful for estimating the detriment relative to non-uniform and partial-body irradiation; for optimizing radiological procedures involving multiple organs or tissues; for drawing comparisons between alternative procedures or background radiation levels; and for estimating the relative detriment attributed to multiple exposures or different modalities.
The effective dose serves to support regulatory documents and comparative assessments of professional practices, despite of the fact that its quantity is not able to represent the stochastic health risk resulting from exposures of a given worker or other individual.
For the medical community, the principle of justifying radiological procedures is more important than the determination of doses through the use of quantities that are not applicable to the estimation of risks It is understood that this is a factor, which affects radiation protection more significantly than does the determination of the individual dose.
ICRP Publication Ann ICRP. Evolution over the past century of quantities and units in radiation dosimetry.
J Radiol Prot. The meaning and the principle of determination of the effective dose equivalent in radiation protection. Radiat Prot Dosimetry.
Assessment of lifetime attributable risks from internal radiation exposure
Effective dose - how effective for patients? Radiat Environ Biophys. Available from: www. Med Phys. A survey of organ equivalent and effective doses from diagnostic radiology procedures.
The Recommendations of the International Commission on Radiological Protection
ISRN Radiol. Calibration measurements and standards for radiation protection dosimetry. Organ dose conversion coefficients for external photon irradiation of male and female voxel models.
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School of Physics and Astronomy.The authors stated that the effective dose could be applied as a kind of "whole-body dose equivalent" value related to the risks arising from non-uniform irradiation in different diagnostic modalities.
The use of effective dose can also be useful for the purpose of comparisons between different procedures and techniques, or between different hospitals or countries provided that the reference patient or patient population are similar with respect to age and gender. View Metrics. It should be noted that effective dose was established as a quantity applicable to planned situations. The new recommendations were adopted at the end of an open process lasting nine years.
Based on that argument, they demonstrated support for their previous interpretation, concluding that the use of effective dose is incorrect because of inappropriate simplification of the underlying biological mechanisms and the inadequacy of using weighting factors connected to the definition of the effective dose for a given patient population.
ICRP Publication Lens Eye Toxic Res. Some of the information relevant to this decision is outlined below.
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