scholarly journals THERMOLUMINESCENT DETECTORS FOR SURVEILLANCE STUDIES OF RADIATION EXPOSURE OF THE POPULATION

2016 ◽  
pp. 3-10 ◽  
Author(s):  
Nadezhda Aluker ◽  
Nadezhda Aluker ◽  
Yana Suzdal’tseva ◽  
Yana Suzdal’tseva ◽  
Anna Dulepova ◽  
...  
Keyword(s):  
Aluminum Oxide ◽  
Lithium Fluoride ◽  
Absorbed Dose ◽  
Ir Detectors ◽  
Surveillance Studies ◽  
Absorbed Doses ◽  
Dosimetric Monitoring ◽  
Thermoluminescence Dosimetry ◽  
Different Types ◽  
Thermoluminescent Detectors

Luminescent glow occurring in a substance exposed to ionizing radiation (IR) in the process of heating, thermoluminescence (TL) is now an effective method of registration of radiation-absorbed doses. It is important to be aware that the correct absorbed dose when exposed to mixed radiation with unknown characteristics is determined in the material of detector as well as in materials similar in composition (Z eff) and density [1-3]. In this connection, it is expedient to use different types of detectors for solution of different dosimetric problems. This study gives a comparison of the performance characteristics of TLD-K thermoluminescent detectors [4, 5], made of sodium silicate glass ceramic with the characteristics of IR detectors made of luminophors based on lithium fluoride monocrystals containing impurities of titanium and magnesium (TLD -100) [6, 7] and an anion of defective aluminum oxide (TLD-500) [8-11] widely used in thermoluminescence dosimetry. Comparison of a number of parameters that are relevant to the use of detectors in dosimetric monitoring of environment favors TLD-K detectors. The studies were carried out on the territory of the Kemerovo region.

scholarly journals α-Particle-induced DNA damage tracks in peripheral blood mononuclear cells of [223Ra]RaCl2-treated prostate cancer patients

2021 ◽  
Author(s):  
S. Schumann ◽  
U. Eberlein ◽  
C. Lapa ◽  
J. Müller ◽  
S. Serfling ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Dna Damage ◽  
Cancer Patients ◽  
Peripheral Blood Mononuclear Cells ◽  
Peripheral Blood ◽  
Mononuclear Cells ◽  
Absorbed Dose ◽  
Peripheral Blood Mononuclear ◽  
Absorbed Doses ◽  
Blood Mononuclear Cells

Abstract Purpose One therapy option for prostate cancer patients with bone metastases is the use of [223Ra]RaCl2. The α-emitter 223Ra creates DNA damage tracks along α-particle trajectories (α-tracks) in exposed cells that can be revealed by immunofluorescent staining of γ-H2AX+53BP1 DNA double-strand break markers. We investigated the time- and absorbed dose-dependency of the number of α-tracks in peripheral blood mononuclear cells (PBMCs) of patients undergoing their first therapy with [223Ra]RaCl2. Methods Multiple blood samples from nine prostate cancer patients were collected before and after administration of [223Ra]RaCl2, up to 4 weeks after treatment. γ-H2AX- and 53BP1-positive α-tracks were microscopically quantified in isolated and immuno-stained PBMCs. Results The absorbed doses to the blood were less than 6 mGy up to 4 h after administration and maximally 16 mGy in total. Up to 4 h after administration, the α-track frequency was significantly increased relative to baseline and correlated with the absorbed dose to the blood in the dose range < 3 mGy. In most of the late samples (24 h – 4 weeks after administration), the α-track frequency remained elevated. Conclusion The γ-H2AX+53BP1 assay is a potent method for detection of α-particle-induced DNA damages during treatment with or after accidental incorporation of radionuclides even at low absorbed doses. It may serve as a biomarker discriminating α- from β-emitters based on damage geometry.

scholarly journals Is nuclear medicine really safe?

2002 ◽  
Vol 45 (spe) ◽  
pp. 115-118
Author(s):  
Nicole Colas-Linhart
Keyword(s):  
Nuclear Medicine ◽  
Human Serum Albumin ◽  
Radiation Dose ◽  
Serum Albumin ◽  
Human Serum ◽  
Absorbed Dose ◽  
Cellular Level ◽  
Whole Body ◽  
Absorbed Doses ◽  
Standard Models

In nuclear medicine, radiation absorbed dose estimates calculated by standard models at the whole body or organ are very low. At cellular level, however, the heterogeneity of radionuclide distributions of radiation dose patterns may be significant. We present here absorbed doses at cellular level and evaluate their possible impact on the usually assumed risk/benefit relationships in nuclear medicine studies. The absorbed dose values calculated are surprisingly high, and are difficult to interpret. In the present study, we show calculated doses at the cellular level and discuss possible biological consequences, for two radiopharmaceuticals labelled with technetium-99m: human serum albumin microspheres used for pulmonary scintigrapies and HMPAO used to labelled leukocytes.

Lithium Fluoride Thermoluminescence Dosimetry

Radiology ◽  
1966 ◽  
Vol 87 (5) ◽  
pp. 938-943 ◽  
Author(s):  
R. G. Worton ◽  
A. F. Holloway
Keyword(s):  
Lithium Fluoride ◽  
Thermoluminescence Dosimetry

scholarly journals Is it necessary to reduce the radioiodine dose in patients with thyroid cancer and renal failure?

2010 ◽  
Vol 54 (4) ◽  
pp. 413-418 ◽  
Author(s):  
José Willegaignon ◽  
Verena Pinto Brito Ribeiro ◽  
Marcelo Sapienza ◽  
Carla Ono ◽  
Tomoco Watanabe ◽  
...  
Keyword(s):  
Thyroid Cancer ◽  
Dose Adjustment ◽  
Absorbed Dose ◽  
Whole Body ◽  
Half Time ◽  
Dialysis Therapy ◽  
Absorbed Doses ◽  
131I Activity ◽  
Dosimetric Data ◽  
Higher Doses

The objective of this study were to obtain dosimetric data from a patient with thyroid cancer simultaneously undergoing peritoneal dialysis therapy, so as to determine the appropriate amount of 131I activity to be applied therapeutically. Percentages of radioiodine in the blood and the whole-body were evaluated, and radiation absorbed doses were calculated according to OLINDA/EXM software. Whole-body 131I effective half-time was 45.5 hours, being four times longer than for patients without any renal dysfunction. Bone-marrow absorbed dose was 0.074 mGy/MBq, with ablative procedure maintenance at 3.7 GBq, as the reported absorbed dose was insufficiently restrictive to change the usual amount of radioiodine activity administered for ablation. It was concluded that radioiodine therapeutic-dose adjustment, based on individual patient dosimetry, is an important way of controlling therapy. It also permits the safe and potential delivery of higher doses of radiation to tumors and undesirable tissues, with a minimum of malignant effects on healthy tissues.

The Effect of Radiation Sterilization on the Stress-Strain Properties of Non-Woven Materials -Based on Polypropylene

2020 ◽  
Vol 992 ◽  
pp. 403-408
Author(s):  
Elvina R. Rakhmatullina ◽  
M.S. Lisanevich ◽  
Rezeda Yu. Galimzyanova ◽  
Yu.N. Khakimullin
Keyword(s):  
Ionizing Radiation ◽  
Absorbed Dose ◽  
Breaking Load ◽  
Radiation Sterilization ◽  
Stress Strain ◽  
Cross Direction ◽  
Absorbed Doses ◽  
Single Use ◽  
The Cross ◽  
The Web

Non-woven materials are widely used for the manufacture of disposable medical clothing and underwear. Radiation is widely used to sterilize single-use medical devices. The paper analyzes the effect of ionizing radiation at absorbed doses of 0-60 kGy on the stress-strain properties of medical non-woven spanmelt material based on polypropylene obtained by blow-molding technology. It has been established that ionizing radiation significantly reduces the breaking load and elongation in the machine and cross directions of the web. For this type of material, the most critical is the decrease in strength in the cross direction of the web, primarily because the level of strength in the cross direction of spanmelt materials is generally low. Sterilization by ionizing radiation further reduces strength and leads to the fact that non-woven materials irradiated with an absorbed dose of 50-60 kGy are close to unacceptable values in accordance with the requirements of EN 13975-2011.

ASSESSMENT OF NATURAL RADIOACTIVITY LEVELS AND RADIOLOGICAL HAZARDS IN BUILDING MATERIALS

2020 ◽  
Vol 188 (3) ◽  
pp. 316-321
Author(s):  
Fei Tuo ◽  
Xuan Peng ◽  
Qiang Zhou ◽  
Jing Zhang
Keyword(s):  
Building Materials ◽  
Gamma Ray ◽  
Absorbed Dose ◽  
Gamma Ray Spectrometry ◽  
Absorbed Dose Rate ◽  
Radium Equivalent Activity ◽  
Radiological Hazards ◽  
Radium Equivalent ◽  
Different Types ◽  
Radioactivity Levels

Abstract Radioactivity of 226Ra, 232Th, and 40K were measured in a total of 92 samples, including eight commonly used types of building materials that were obtained from local manufacturers and suppliers in Beijing. Concentrations were determined using high-purity germanium gamma-ray spectrometry. The 226Ra, 232Th, and 40K activity concentrations in all samples varied from 10.1 to 661, 3.3 to 555 and 3.2 to 2945 Bq per kg with an average of 127.8, 114.8, and 701.5 Bq per kg, respectively. The potential radiological hazards were estimated by calculating the absorbed dose rate (D), radium equivalent activity (Raeq), external hazard (Hex), and internal hazard (Hin) indices. The investigated building materials were classified into different types according to the radioactivity levels. Results from this research will provide a reference for the acquisition, sales, and use of building materials. Attention should be paid to the use of coal cinder brick, ceramic, and granite in the construction of dwellings.

scholarly journals Absorbed dose evaluation at different organs after 131I oral contamination of two Wistar rat models

2019 ◽  
Vol 14 ◽  
pp. 07004
Author(s):  
Meriem Mezaguer-Lekouaghet ◽  
Eric Blanchardon ◽  
Abdelwahab Badreddine ◽  
Jean-Marc Bertho ◽  
Maamar Souidi ◽  
...  
Keyword(s):  
Rat Model ◽  
Bladder Wall ◽  
Thyroid Tissue ◽  
Absorbed Dose ◽  
Emission Spectra ◽  
Wistar Rat ◽  
Radiation Emission ◽  
Rat Models ◽  
Absorbed Doses ◽  
The Difference

Iodine-131 (131I) is one of the most frequently used radionuclides for diagnosis and therapy of thyroid diseases. It is administered orally in the treatment of cancer to eliminate the residual postoperative microscopic tumor foci, and the residual normal thyroid tissue for early detection of recurrence [1]. The comparative behavior of 131I concentration into two animalmodels with total and partial thyroid has been investigated in our previous work [2]. The accumulated activities have been measured in fourteen organs. In this study, the mean absorbed doses resulting from 131I accumulated in all organs have been evaluated using RODES software [3, 4]. With this software, mean absorbed doses were calculatedfor selected organs (thyroid, lungs, heart, liver, kidneys, stomach, spleen, large and small intestine, testes, urinary bladder wall) by combining the specific absorbed fractions (SAF) of energy with radiation emission spectra and biokinetic data determined from our previous experimental study [2]. Calculations were based on the 131I photon and electron emissions reported by [5] and SAFs previously calculated by Monte Carlo simulation in the voxel phantom of an adult male rate [3, 4]. The obtained results show high absorbed dosesdeliveredto stomach and lungs for both models compared to other organs. The dose received by the testes and salivary glands is found to be higher in the case of the rat model without thyroid. Conversely, the spleen and bladder wall received lower doses in this latter model compared to those received by the rat model with thyroid. One can also note that the difference in mean absorbed dose received by liver, lungs, heart, and walls of the stomach is not significant between the two rat models.

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