With great interest we have read the paper “Pregnancy Screening before Diagnostic Radiography in Emergency Department; an Educational Review†by A.I. Abushouk et al. (1). We agree with the authors ...that unnecessary fetal radiation exposure should be avoided and that pregnancy screening can be a means to accomplish this. However, in their paper the authors suggest in several instances that radiological imaging during pregnancy can lead to teratogenic effects. In the Abstract it is stated: “Radiation exposure during pregnancy may have serious teratogenic effects to the fetus. Therefore, checking the pregnancy status before imaging women of child bearing age can protect against these effects.â€, and in the Introduction: “Therefore, checking the pregnancy status before imaging women of child bearing age can protect against radiation teratogenic effects.â€
The gamma radiation shielding ability for CaO-K2O-Na2O-P2O5 glasses were experimentally determined between 0.0595 and 1.41 MeV. The experimental MAC results were compared with theoretical results ...obtained from the XCOM software to test the accuracy of the experimental values. Additionally, the effect of increasing the P2O5 in the glass composition, or reducing the Na2O content, was evaluated at varying energies. For the fabricated glasses, the experimental data strongly agreed with the XCOM results. The effective atomic number (Zeff) of the fabricated glasses was also determined. The Zeff values start out at their maximum (12.41–12.55) at the lowest tested energy, 0.0595 MeV, and decrease to 10.69–10.80 at 0.245 MeV. As energy further increases, the Zeff values remain almost constant between 0.344 and 1.41 MeV. The mean free path (MFP) of the fabricated glasses is investigated and we found that the lowest MFP value occurs at the lowest tested energy, 0.0595 MeV, and lies within the range of 1.382–1.486 cm, while the greatest MFP can be found at the highest tested energy, 1.41 MeV, within the range of 8.121–8.656 cm. At all energies, the KCNP40 sample has the lowest MFP, while the KCNP60 sample has the greatest. The half value layer (HVL) for the KCNP-X glasses is determined. For all the selected energies, the HVL values follow the order of KCNP40 < KCNP45 < KCNP50 < KCNP55 < KCNP60. The HVL of the KCNP50 sample increased from 0.996 to 2.663, 3.392, 4.351, and 5.169 cm for energies of 0.0595, 0.245, 0.444, 0.779, and 1.11 MeV, respectively. The radiation protection efficiency (RPE) results reveal that decreasing the P2O5 content in the glasses improves the radiation shielding ability of the samples. Thus, the KCNP40 sample has the best potential for photon attenuation applications.
The benefits of cardiac imaging are immense, and modern medicine requires the extensive and versatile use of a variety of cardiac imaging techniques. Cardiologists are responsible for a large part of ...the radiation exposures every person gets per year from all medical sources. Therefore, they have a particular responsibility to avoid unjustified and non-optimized use of radiation, but sometimes are imperfectly aware of the radiological dose of the examination they prescribe or practice. This position paper aims to summarize the current knowledge on radiation effective doses (and risks) related to cardiac imaging procedures. We have reviewed the literature on radiation doses, which can range from the equivalent of 1-60 milliSievert (mSv) around a reference dose average of 15 mSv (corresponding to 750 chest X-rays) for a percutaneous coronary intervention, a cardiac radiofrequency ablation, a multidetector coronary angiography, or a myocardial perfusion imaging scintigraphy. We provide a European perspective on the best way to play an active role in implementing into clinical practice the key principle of radiation protection that: 'each patient should get the right imaging exam, at the right time, with the right radiation dose'.
National Council on Radiation Protection and Measurements Commentary 27 examines recent epidemiologic data primarily from low-dose or low dose-rate studies of low linear-energy-transfer radiation and ...cancer to assess whether they support the linear no-threshold model as used in radiation protection. The commentary provides a critical review of low-dose or low dose-rate studies, most published within the last 10 y, that are applicable to current occupational, environmental, and medical radiation exposures. The strengths and weaknesses of the epidemiologic methods, dosimetry assessments, and statistical modeling of 29 epidemiologic studies of total solid cancer, leukemia, breast cancer, and thyroid cancer, as well as heritable effects and a few nonmalignant conditions, were evaluated. An appraisal of the degree to which the low-dose or low dose-rate studies supported a linear no-threshold model for radiation protection or on the contrary, demonstrated sufficient evidence that the linear no-threshold model is inappropriate for the purposes of radiation protection was also included. The review found that many, though not all, studies of solid cancer supported the continued use of the linear no-threshold model in radiation protection. Evaluations of the principal studies of leukemia and low-dose or low dose-rate radiation exposure also lent support for the linear no-threshold model as used in protection. Ischemic heart disease, a major type of cardiovascular disease, was examined briefly, but the results of recent studies were considered too weak or inconsistent to allow firm conclusions regarding support of the linear no-threshold model. It is acknowledged that the possible risks from very low doses of low linear-energy-transfer radiation are small and uncertain and that it may never be possible to prove or disprove the validity of the linear no-threshold assumption by epidemiologic means. Nonetheless, the preponderance of recent epidemiologic data on solid cancer is supportive of the continued use of the linear no-threshold model for the purposes of radiation protection. This conclusion is in accord with judgments by other national and international scientific committees, based on somewhat older data. Currently, no alternative dose-response relationship appears more pragmatic or prudent for radiation protection purposes than the linear no-threshold model.
Yttrium-90 microsphere brachytherapy of the liver exploits the distinctive features of the liver anatomy to treat liver malignancies with beta radiation and is gaining more wide spread clinical use. ...This report provides a general overview of microsphere liver brachytherapy and assists the treatment team in creating local treatment practices to provide safe and efficient patient treatment. Suggestions for future improvements are incorporated with the basic rationale for the therapy and currently used procedures. Imaging modalities utilized and their respective quality assurance are discussed. General as well as vendor specific delivery procedures are reviewed. The current dosimetry models are reviewed and suggestions for dosimetry advancement are made. Beta activity standards are reviewed and vendor implementation strategies are discussed. Radioactive material licensing and radiation safety are discussed given the unique requirements of microsphere brachytherapy. A general, team-based quality assurance program is reviewed to provide guidance for the creation of the local procedures. Finally, recommendations are given on how to deliver the current state of the art treatments and directions for future improvements in the therapy.
This work aims to investigate the structure and the radiation shielding efficiency of various types of superconducting ceramics of REBCO (RE: La, Sm, Gd, Eu, Er, Nd, and Dy). The different samples ...were made via the conventional solid-state reaction route (SSR). The structural analysis via the XRD technique showed that all ceramics crystallized in an orthorhombic structure, except for LaBCO ceramic, which has a tetragonal crystalline structure. The lattice parameters showed a variation with a relative change in the ionic radius of RE elements. The crystallite sizes D were calculated using the Scherrer equation. The highest value was obtained in ErBCO (87.19 nm) and DyBCO (92.02 nm) ceramics. Also, the density of different ceramics shows a variance with the respect to ionic radii and atomic numbers of RE elements, and the highest values were obtained for ErBCO and DyBCO ceramics. The radiation shielding analysis was performed by Monte Carlo simulation. Different important shielding parameters were calculated. The results showed all these ceramics have high attenuation strength at low energy, and this competence to shield the radiation is dropped with increasing the energy. The LAC for all ceramics is (in order of 0.85–1.14 cm−1 at 0.244 MeV, and in order of 0.356 and 0.444 cm−1 at 0.511 MeV. Dy-123 and Er-123 have the highest LAC values, while La-123 has the least. The half-value layer (Δ0.5) results proved that ceramics samples made with comparatively high density showed an outstandingly better performance in attenuating the radiation compared to the low-density ceramics. Also, the Δ0.5 results showed that the utilization of Dy and Er has a notable effect in reducing the thickness of the ceramic since the least Δ0.5 is found for Dy-123 followed by Er-123. These results could be original references for future studies aimed at developing new and innovative ceramics exploited as radiation-protective materials.
•Synthesis of (RE)BCO (RE = La, Gd, Sm, Eu, Nd, Er, Dy) ceramics via solid state reaction.•The unit cell volume showed variation with a relative change in ionic radius of RE elements.•γ-ray attenuation ability of (RE)BCO ceramics was assessed via Monte Carlo simulation.•The least Δ0.5 is found for DyBCO followed by ErBCO.•DyBCO possesses the highest radiation protection efficiency (RPE).
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