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

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.

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

Annals of the ICRP ◽

10.1016/j.icrp.2012.06.003 ◽

2012 ◽

Vol 41 (3-4) ◽

pp. 57-63 ◽

Cited By ~ 1

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.

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Effective dose: a radiation protection quantity

Annals of the ICRP ◽

10.1016/j.icrp.2012.06.022 ◽

2012 ◽

Vol 41 (3-4) ◽

pp. 117-123 ◽

Cited By ~ 12

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.

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Annual Effective Dose from Natural Background Radiation in Pokhara, Nepal

Asian Journal of Research and Reviews in Physics ◽

10.9734/ajr2p/2020/v3i230119 ◽

2020 ◽

pp. 36-42

Author(s):

S. P. Gautam ◽

A. Silwal ◽

S. Acharya ◽

B. Aryal

Keyword(s):

Effective Dose ◽

Dose Rate ◽

Background Radiation ◽

Annual Effective Dose ◽

Radiological Protection ◽

Natural Background ◽

Radiation Dose Rate ◽

Natural Background Radiation ◽

Effective Dose Rate ◽

Annual Effective Dose Rate

Measurement of outdoor natural background radiation doses at different locations of Pokhara city, Nepal was carried out using GCA-07W, Nuclear Regulatory Commission (NRC) certified Geiger Muller (GM) detector. From the measurements, the least value of background radiation dose rate was found to be 0.26 ± 0.08 μSv/hr for Mahendra Cave area, and the highest value of dose rate was found to be 0.65 ± 0.12 μSv/hr for Prithvi Narayan Campus. The average annual effective dose rate of Pokhara city was found to be 0.56 ± 0.12 mSv/yr ranging from 0.31 ± 0.09 mSv/yr to 0.80 ± 0.14 mSv/yr. The radiation levels in Pokhara, the most populated city of the western development region of Nepal, were found to be within the secure limit for areas of the normal background recommended by the International Commission on Radiological Protection (ICRP) (1 mSv/yr). Further, the current result was compared with the previous study of annual effective dose rate measured in Kathmandu city. Comparable value of the average annual effective dose rate in Pokhara and Kathmandu was obtained.

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Study of natural background radiation in Kathmandu Valley

BIBECHANA ◽

10.3126/bibechana.v16i0.21605 ◽

2018 ◽

Vol 16 ◽

pp. 187-195

Author(s):

Parkash Pantha ◽

Tanka Prasad Bhusal ◽

Budha Ram Shah ◽

Rajendra Prasad Koirala

Keyword(s):

Effective Dose ◽

Dose Rate ◽

Background Radiation ◽

Annual Effective Dose ◽

Kathmandu Valley ◽

Radiological Protection ◽

Average Dose ◽

Natural Background ◽

Natural Background Radiation ◽

Dose Rates

The study of natural background radiation dose at thirty two locations of Kathmandu valley has been done successfully using the instrument Radalert 100. The average dose rates and annual effective dose were measured. From the measurements, the least value of average dose rate was found to be (22.3±3.9)×10-3 mR/hr for Sundhara and the greatest value of average dose rate was found to be (37.7±7)×10-3 mR/hr for Budhanilkantha 3. As per the annual effective dose, the least value was 0.391 mSv/yr for Sundhara and the greatest value was 0.661 mSv/yr for Budhanilkantha 3. The average annual effective dose of Kathmandu valley was 0.475 mSv/yr ranging from 0.391 mSv/yr to 0.661 mSv/yr. The values thus obtained were compared to the worldwide average value of annual effective dose, 0.48 mSv/yr. Also, the obtained values were compared to the legal dose limit (annual effective dose), 1 mSv/yr set by International Commission on Radiological Protection (ICRP) for non-radiation workers and members of public. Among these thirty two locations, eight locations were chosen such that they had larger range of the observed dose rates. Those eight locations were re-observed. Further, Chi-square test was carried out to test whether the observed dose rates were following normal distribution or not. From the calculation, it was observed that the observed dose rates were following the normal distribution.BIBECHANA 16 (2019) 187-195

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Assessment of background ionizing radiation dose levels in quarry sites located in Ebonyi State, Nigeria

Journal of Applied Sciences and Environmental Management ◽

10.4314/jasem.v24i10.17 ◽

2020 ◽

Vol 24 (10) ◽

pp. 1821-1826

Author(s):

E.O. Echeweozo ◽

F.O. Ugbede

Keyword(s):

Radiation Dose ◽

Ionizing Radiation ◽

Effective Dose ◽

Dose Rate ◽

Annual Effective Dose ◽

Nuclear Radiation ◽

Radiological Protection ◽

Continuous Exposure ◽

Average Value ◽

Dose Levels

The study presents a radiometric survey of Background Ionizing Radiation (BIR) dose levels in ten quarry sites located in Ebonyi State, Nigeria. In-situ BIR dose rate measurements, by means of nuclear radiation survey meter, at 1 m above ground level were carried out at the excavation section (ES) and quarrying section (QS) of the investigated quarry sites. The obtained results indicated dose rates ranging from from 0.14 to 0.18 μSv/h with mean of 0.15±0.01 μSv/h at the ES and 0.16 to 0.19 μSv/h with mean value of 0.18±0.01 μSv/h at the QS. While the values obtained at the QS are respectively higher than those measured at the ES, they are all higher than the worldwide average value of 84 nSv/h signifying BIR elevated environments. The estimated mean annual effective dose (AED) and excess lifetime cancer risk (ELCR) are 0.27±0.03 mSv/y and 0.94×10–3 respectively at the ES and 0.31±0.02 mSv/y and 1.07×10–3 at the QS. The obtained AED values for all the sites are well above the outdoor worldwide average value of 0.07 mSv/y but lower than the International Commission on Radiological Protection recommended permissible limits of 1.0 mSv/y for the general public. Generally, the BIR levels of the quarry sites are within acceptable limits and no immediate radiological health threat may be derived from the current levels. However, long-term health effects due to continuous exposure to low-level radiation doses may manifested in future over a lifetime exposure of 70 years as indicated by the ELCR values. Keywords: Background ionizing radiation, Dose rate, Annual effective dose, Quarry site, Ebonyi State

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Radiation exposure of the staff at the therapeutic and diagnostic nuclear medicine department

Nuklearmedizin ◽

10.3413/nukmed-0163 ◽

2008 ◽

Vol 47 (04) ◽

pp. 175-177 ◽

Cited By ~ 4

Author(s):

J. Dolezal

Keyword(s):

Nuclear Medicine ◽

Radiation Exposure ◽

Effective Dose ◽

Radiation Protection ◽

Annual Effective Dose ◽

Protection Measures ◽

Professional Groups ◽

Personal Dosimetry ◽

The Mean ◽

Administered Activity

SummaryAim: To assess a radiation exposure and the quality of radiation protection concerning a nuclear medicine staff at our department as a six-year retrospective study. Therapeutic radionuclides such as 131I, 153Sm, 186Re, 32P, 90Y and diagnostic ones as a 99mTc, 201Tl, 67Ga, 111In were used. Material, method: The effective dose was evaluated in the period of 2001–2006 for nuclear medicine physicians (n = 5), technologists (n = 9) and radiopharmacists (n = 2). A personnel film dosimeter and thermoluminescent ring dosimeter for measuring (1-month periods) the personal dose equivalent Hp(10) and Hp(0,07) were used by nuclear medicine workers. The wearing of dosimeters was obligatory within the framework of a nationwide service for personal dosimetry. The total administered activity of all radionuclides during these six years at our department was 17,779 GBq (99mTc 14 708 GBq, 131I 2490 GBq, others 581 GBq). The administered activity of 99mTc was similar, but the administered activity of 131I in 2006 increased by 200%, as compared with the year 2001. Results: The mean and one standard deviation (SD) of the personal annual effective dose (mSv) for nuclear medicine physicians was 1.9 ± 0.6, 1.8 ± 0.8, 1.2 ± 0.8, 1.4 ± 0.8, 1.3 ± 0.6, 0.8 ± 0.4 and for nuclear medicine technologists was 1.9 ± 0.8, 1.7 ± 1.4, 1.0 ± 1.0, 1.1 ± 1.2, 0.9 ± 0.4 and 0.7 ± 0.2 in 2001, 2002, 2003, 2004, 2005 and 2006, respectively. The mean (n = 2, estimate of SD makes little sense) of the personal annual effective dose (mSv) for radiopharmacists was 3.2, 1.8, 0.6, 1.3, 0.6 and 0.3. Although the administered activity of 131I increased, the mean personal effective dose per year decreased during the six years. Conclusion: In all three professional groups of nuclear medicine workers a decreasing radiation exposure was found, although the administered activity of 131I increased during this six-year period. Our observations suggest successful radiation protection measures at our department.

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MINIMIZING THE EXPOSURE TO THE EYE LENS OF RADIOLOGIC TECHNOLOGISTS ASSISTING PATIENTS DURING CHEST X RAYS: A PHANTOM STUDY

Radiation Protection Dosimetry ◽

10.1093/rpd/ncab019 ◽

2021 ◽

Vol 193 (1) ◽

pp. 43-54

Author(s):

Yasuda Mitsuyoshi ◽

Funada Tomoya ◽

Sato Hisaya ◽

Kato Kyoichi

Keyword(s):

Radiation Protection ◽

Phantom Study ◽

International Commission ◽

Eye Lens ◽

Radiological Protection ◽

X Rays ◽

Radiologic Technologists ◽

Maximum Reduction ◽

The Right

Abstract As chest x rays involve risks of patients falling, radiologic technologists (technologists) commonly assist patients, and as the assistance takes place near the patients, the eye lenses of the technologists are exposed to radiation. The recommendations of the International Commission on Radiological Protection suggest that the risk of developing cataracts due to lens exposure is high, and this makes it necessary to reduce and minimize the exposure. The present study investigated the positions of technologists assisting patients that will minimize exposure of the eye lens to radiation. The results showed that it is possible to reduce the exposure by assisting from the following positions: 50% at the sides rather than diagonally behind, 10% at the right side of the patient rather than the left and 40% at 250 mm away from the patient. The maximum reduction with radiation protection glasses was 54% with 0.07 mmPb and 72% with 0.88 mmPb.

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Radon Activity Concentrations in Natural Hot Spring Water: Dose Assessment and Health Perspective

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph18030920 ◽

2021 ◽

Vol 18 (3) ◽

pp. 920

Author(s):

Eka Djatnika Nugraha ◽

Masahiro Hosoda ◽

June Mellawati ◽

Untara Untara ◽

Ilsa Rosianna ◽

...

Keyword(s):

Public Health ◽

Effective Dose ◽

Radiation Protection ◽

Water Samples ◽

Hot Springs ◽

Hot Spring ◽

Annual Effective Dose ◽

Spring Water ◽

Dose Assessment ◽

West Java

The world community has long used natural hot springs for tourist and medicinal purposes. In Indonesia, the province of West Java, which is naturally surrounded by volcanoes, is the main destination for hot spring tourism. This paper is the first report on radon measurements in tourism natural hot spring water in Indonesia as part of radiation protection for public health. The purpose of this paper is to study the contribution of radon doses from natural hot spring water and thereby facilitate radiation protection for public health. A total of 18 water samples were measured with an electrostatic collection type radon monitor (RAD7, Durridge Co., USA). The concentration of radon in natural hot spring water samples in the West Java region, Indonesia ranges from 0.26 to 31 Bq L−1. An estimate of the annual effective dose in the natural hot spring water area ranges from 0.51 to 0.71 mSv with a mean of 0.60 mSv for workers. Meanwhile, the annual effective dose for the public ranges from 0.10 to 0.14 mSv with an average of 0.12 mSv. This value is within the range of the average committed effective dose from inhalation and terrestrial radiation for the general public, 1.7 mSv annually.

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