On Some Methodological Issues of Studying Cytogenetic Effects in Cancer Patients Treated with Neutron Therapy Using U-120 Cyclotron

2018 ◽  
Vol 63 (2) ◽  
pp. 47-54
Author(s):  
В. Лисин ◽  
V. Lisin
Keyword(s):  
Radiation Field ◽  
Chromosome Aberrations ◽  
Absorbed Dose ◽  
Neutron Radiation ◽  
The Body ◽  
Beam Intensity ◽  
Whole Body ◽  
Γ Radiation ◽  
Cytogenetic Effect ◽  
Tissue Equivalent

Purpose: To study dosimetric characteristics of neutron radiation field, to determine their role in the formation of the total cytogenetic effect in the patient’s body and to assess the cytogenetic dosimetry capabilities in improving the quality of NT. Material and methods: A therapeutic beam with the average neutron energy of ~6.3 MeV was obtained from the V-120 cyclotron. The radiation field of the beam was investigated with the help of two ionization chambers with different sensitivity to neutrons. Chamber with high and low sensitivities were made of polyethylene and graphite, respectively. To exclude the uncertainty associated with the change in beam intensity in time, a dosimeter monitor operating in the integral mode was used. Results: The dependence of the monitor factor on the irradiated area was measured. The distributions of the absorbed dose of neutrons and γ-radiation over the depth of the tissue-equivalent medium were found. The contribution of γ-radiation to the neutron dose was increased from ~10 % at the entry to the medium to ~30 % at a depth of 16 cm. Dose distributions of scattered neutron and γ-radiation in the plane of the end face of the forming device were obtained. The contribution of these radiations to the dose received by the patient’s body was estimated. This contribution was shown to be comparable with that from the therapeutic beam. The analysis of the influence of NT on the estimation of the frequency of chromosome aberrations in the blood of patients was carried out. Conclusion: The frequency of chromosome aberrations in the blood of patients was determined by the whole-body dose, including dose due to scattered radiation. When using equal focal doses, the cytogenetic effect was found to be dependent on the area of the irradiated field and the depth of the tumor in the patient’s body. The differences in the RBE of neutrons and γ-radiation as well as the instability of the therapeutic neutron beam intensity create uncertainties that do not allow for the necessary control over the doses using the cytogenetic dosimetry. Therefore, cytogenetic dosimetry should be combined with an effective instrument dosimetry method. The use of biodosimetry based on the assessment of the frequency of chromosome aberrations is promising for controlling the average whole-body dose, on which the overall radiation response of the body depends.

scholarly journals High-sensitive colour indicator of absorbed dose of epithermal neutrons radiation

2022 ◽  
Vol 2155 (1) ◽  
pp. 012032
Author(s):  
G A Kulabdullaev ◽  
A A Kim ◽  
G T Djuraeva ◽  
A F Nebesniy ◽  
G A Abdullaeva ◽  
...  
Keyword(s):  
Absorbed Dose ◽  
High Sensitivity ◽  
Neutron Radiation ◽  
Arsenazo Iii ◽  
Indicator Solution ◽  
Tissue Equivalent ◽  
Epithermal Neutrons ◽  
Delayed Measurement ◽  
Artificial Illumination ◽  
Error Of Measurement

Abstract In our study, the high-sensitivity colour indicator of the absorbed dose of radiation of epithermal neutrons with energy 0 to 10 keV for dosimetry of low-energy neutrons was developed. We had been developed an indicator on the basis of the dye solution of arsenazo III and gadopentetic acid, allowing precisely define of absorbed dose in the range 2 to 103 Gy. The properties of arsenazo III as metallic indicator, which changes colour after binding of free ions of metals, were used. Colour of the indicator solution before irradiation and after it is stable enough in time at storage in the dark, at artificial illumination or at scattered sunlight. The developed indicator, consisting of a solution of arsenazo III and gadopentetic acid, allows estimating the absorbed dose of epithermal neutron irradiation with good accuracy and reduces the error of measurement related to changing colour of dye under the influence of other factors (light, temperature etc.) Dosimeter is tissue-equivalent and possesses a high-sensitivity neutron radiation due to the content of gadolinium in solution, which has great neutron capture cross-section. The developed dosimeter persists spectrophotometric characteristics after irradiaion within few weeks that allows to use it for measurement of the absorbed dose, both in real time mode and with the delayed measurement within few weeks.

Operational Values of Radioactive Skin Contamination in the Case of Radiological Accident

2020 ◽  
Vol 65 (3) ◽  
pp. 20-26
Author(s):  
M. Grachev ◽  
Yu. Salenko ◽  
Yu. Abramov ◽  
G. Frolov ◽  
V. Klochkov ◽  
...  
Keyword(s):  
Experimental Studies ◽  
Absorbed Dose ◽  
The Body ◽  
Surface Contamination ◽  
Radioactive Material ◽  
Whole Body ◽  
Laboratory Animals ◽  
Intact Skin ◽  
Radioactive Substances ◽  
Skin Contamination

Purpose: Development of recommendations on the use in medical practice of institutions under FMBA of Russia of operational values of radioactive skin contamination in the event of radiological accidents. Material and methods: The easily measured radiation parameters were used as operational values: ambient dose equivalent rate (ADER) of γ-radiation, density of skin contamination with γ-, β- and α-emitting radionuclides. Operational values ​​of skin contamination were estimated on the basis of experimental data described in the literature and models on the kinetics of radioactive substances transport in the body, accepted values ​​of dose criteria for deterministic and stochastic effects. The estimation of radioactive material resorption through the skin was based on the results of experimental studies in laboratory animals (mainly piglets) for a limited set of chemical compounds of radionuclides. Results: The values of γ-ADER of the main dose-forming radionuclides measured at a distance of 10 cm from the skin surface in the range of 10–1000 μSv/h and the possible health effects due to the skin exposure and the intake of radioactive substances into the body were presented. In the IAEA recommendations, the level of skin contamination at 1 µSv/h is considered as a significant operational value according to the criterion of radioactive substances intake through the mouth from the contaminated surface of the hands. However, in our opinion, this estimate is excessively conservative; therefore it is not included in the recommended operational values. If the skin is contaminated with γ-β-emitting radionuclide solutions at a surface contamination higher than 106 Bq/cm2 (ADER ≥1000 µSv/h), the out of turn emergency decontamination should be carried out. Obligatory indications for the whole body counter examination after thorough decontamination and conducting biophysical analysis of bioassay are the following operational values: γ-ADER from the skin > 10 µSv/h; surface contamination of intact skin with β-active radionuclides > 20 000 β-part./(cm2·min); surface contamination of intact skin with α-active radionuclides > 200 α-part./ (cm2·min). Conclusion: The recommended operational values allow preliminarily and promptly to assess the health risk not only in the case of external (contact) exposure of the skin and underlying tissues, but also due to the intake of soluble radioactive substances into the body through intact and damaged (injured) skin. Taking into account the high degree of uncertainty of the estimates obtained, the operational values ​​should be considered as strictly conservative. They should be used only to determinate of urgency of decontamination carrying out for the provision of medical care during the prehospital and early hospital periods with the obligatory follow-up dosimetry examination for the final assessment of absorbed dose.

THE DETERMINATION OF NEUTRON FLUENCE TO ABSORBED DOSE CONVERSION COEFFICIENTS AND RELATIVE BIOLOGICAL EFFECT BASED ON MICRODOSIMETRY MEASUREMENTS

2019 ◽  
Vol 187 (2) ◽  
pp. 262-267
Author(s):  
Weihua Zhang ◽  
Chunjuan Li ◽  
Yisheng Zou ◽  
Yina Liu ◽  
Hailong Luo
Keyword(s):  
Biological Effect ◽  
Absorbed Dose ◽  
Neutron Radiation ◽  
Electron Multiplier ◽  
Lineal Energy ◽  
Radiation Fields ◽  
Empirical Procedure ◽  
Tissue Equivalent ◽  
Conversion Coefficients ◽  
Tissue Equivalent Proportional Counter

Abstract A tissue-equivalent proportional counter (TEPC) is a reference detector to measure microdosimetric quantities. A conventional spherical TEPC and a novel TEPC based on a ceramic thick gas electron multiplier (THGEM) foil were developed to carry out microdosimetric measurements of lineal energy spectra in monoenergetic and 252Cf/241Am-Be neutron radiation fields, and the absorbed dose values had been derived. In order to go further in radiobiology and therapy, the fluence to absorbed dose conversion coefficients in neutron fields were also determined. According to the dose distribution in lineal energy, the neutron relative biological effect (RBE) values were also calculated using an empirical procedure applying biological weighting functions.

scholarly journals Improved Patient Dosimetry at Radioiodine Therapy by Combining the ICRP Compartment Model and the EANM Pre-Therapeutic Standard Procedure for Benign Thyroid Diseases

2021 ◽  
Vol 12 ◽  
Author(s):  
Martin Andersson ◽  
Sören Mattsson
Keyword(s):  
Standard Procedure ◽  
Absorbed Dose ◽  
Compartment Model ◽  
Thyroid Diseases ◽  
The Body ◽  
Whole Body ◽  
Patient Specific ◽  
Transfer Coefficients ◽  
Thyroid Uptake ◽  
Benign Thyroid

Radioactive iodine is commonly used for the treatment of different thyroid conditions since the 1940s. The EANM has developed a standard pre-therapeutic procedure to estimate patient specific thyroid uptake at treatment of benign thyroid diseases. The procedure which models the time dependent fractional thyroid uptake is based on a two-compartment fitting system, one representing the thyroid and the other the blood. The absorbed dose is however only estimated for the thyroid and not for any other organ in the body. A more detailed biokinetic model for iodine is given by the ICRP and includes an iodide transport in the whole body. The ICRP model has 30 different compartments and 48 transfer coefficients to model the biokinetics of iodide and to model different transfer for inorganic iodide and organic iodine. The ICRP model is a recirculation iodine model, and the optimization is performed on the whole model and not exclusively on the thyroid as in the EANM procedure. Combining the EANM method and the ICRP model gives both patient specific estimations of thyroid uptake and retention and include most organs in the body. The new software gives both an improved patient specific dosimetry for the thyroid and an estimation of the absorbed dose to non-target organs and tissues like kidneys, urinary bladder, stomach wall, and uterus. Using the method described in this paper, the repercussions on the daily routines will be minimal.

A Simple and Inexpensive Clinical Whole Body Counter

1976 ◽  
Vol 15 (05) ◽  
pp. 248-253
Author(s):  
A. K. Basu ◽  
S. K. Guha ◽  
B. N. Tandon ◽  
M. M. Gupta ◽  
M. ML. Rehani
Keyword(s):  
The Body ◽  
Whole Body ◽  
Vitro Assay ◽  
Body Counter ◽  
Optimum Parameters ◽  
Whole Body Counter ◽  
Single Detector ◽  
Background Index ◽  
Iodide Crystal

SummaryThe conventional radioisotope scanner has been used as a whole body counter. The background index of the system is 10.9 counts per minute per ml of sodium iodide crystal. The sensitivity and derived sensitivity parameters have been evaluated and found to be suitable for clinical studies. The optimum parameters for a single detector at two positions above the lying subject have been obtained. It has been found that for the case of 131I measurement it is possible to assay a source located at any point in the body with coefficient of variation less than 5%. To add to the versatility, a fixed geometry for in-vitro counting of large samples has been obtained. The retention values obtained by the whole body counter have been found to correlate with those obtained by in-vitro assay of urine and stool after intravenous administration of 51Cr-albumin.

Visualization of Invasion into the Body and Internal Diffusion of Nanoparticles

2008 ◽  
Vol 396-398 ◽  
pp. 569-572
Author(s):  
Fumio Watari ◽  
Shigeaki Abe ◽  
I.D. Rosca ◽  
Atsuro Yokoyama ◽  
Motohiro Uo ◽  
...  
Keyword(s):  
Biomedical Applications ◽  
Fluorescent Microscopy ◽  
The Body ◽  
Internal Diffusion ◽  
Whole Body ◽  
X Ray ◽  
Body Level ◽  
Organ Level ◽  
Level 2 ◽  
Internal Body

Nanoparticles may invade directly into the internal body through the respiratory or digestive system and diffuse inside body. The behavior of nanoparticles in the internal body is also essential to comprehend for the realization of DDS. Thus it is necessary to reveal the internal dynamics for the proper treatments and biomedical applications of nanoparticles. In the present study the plural methods with different principles such as X-ray scanning analytical microscope (XSAM), MRI and Fluorescent microscopy were applied to enable the observation of the internal diffusion of micro/nanoparticles in the (1) whole body level, (2) inner organ level and (3) tissue and intracellular level. Chemical analysis was also done by ICP-AES for organs and compared with the results of XSAM mapping.

scholarly journals Making the choice between bioelectrical impedance measures for body hydration status assessment

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Dmitry M. Davydov ◽  
Andrey Boev ◽  
Stas Gorbunov
Keyword(s):  
Body Schema ◽  
Bioelectrical Impedance ◽  
Information Criterion ◽  
The Body ◽  
Whole Body ◽  
Hydration Status ◽  
Status Assessment ◽  
Best Fitting ◽  
Body Compartments ◽  
Fitting In

AbstractSituational or persistent body fluid deficit (i.e., de- or hypo-hydration) is considered a significant health risk factor. Bioimpedance analysis (BIA) has been suggested as an alternative to less reliable subjective and biochemical indicators of hydration status. The present study aimed to compare various BIA models in the prediction of direct measures of body compartments associated with hydration/osmolality. Fish (n = 20) was selected as a biological model for physicochemically measuring proximate body compartments associated with hydration such as water, dissolved proteins, and non-osseous minerals as the references or criterion points. Whole-body and segmental/local impedance measures were used to investigate a pool of BIA models, which were compared by Akaike Information Criterion in their ability to accurately predict the body components. Statistical models showed that ‘volumetric-based’ BIA measures obtained in parallel, such as distance2/Rp, could be the best approach in predicting percent of body moisture, proteins, and minerals in the whole-body schema. However, serially-obtained BIA measures, such as the ratio of the reactance to resistance and the resistance adjusted for distance between electrodes, were the best fitting in predicting the compartments in the segmental schema. Validity of these results should be confirmed on humans before implementation in practice.

scholarly journals Integumentary Colour Allocation in the Stork Family (Ciconiidae) Reveals Short-Range Visual Cues for Species Recognition

Birds ◽  
2021 ◽  
Vol 2 (1) ◽  
pp. 138-146
Author(s):  
Eduardo J. Rodríguez-Rodríguez ◽  
Juan J. Negro
Keyword(s):  
Short Range ◽  
Visual Cues ◽  
Species Recognition ◽  
The Body ◽  
Whole Body ◽  
Divergent Evolution ◽  
Black And White ◽  
Extant Species ◽  
Chromatic Spectrum ◽  
Mixed Species Flocks

The family Ciconiidae comprises 19 extant species which are highly social when nesting and foraging. All species share similar morphotypes, with long necks, a bill, and legs, and are mostly coloured in the achromatic spectrum (white, black, black, and white, or shades of grey). Storks may have, however, brightly coloured integumentary areas in, for instance, the bill, legs, or the eyes. These chromatic patches are small in surface compared with the whole body. We have analyzed the conservatism degree of colouration in 10 body areas along an all-species stork phylogeny derived from BirdTRee using Geiger models. We obtained low conservatism in frontal areas (head and neck), contrasting with a high conservatism in the rest of the body. The frontal areas tend to concentrate the chromatic spectrum whereas the rear areas, much larger in surface, are basically achromatic. These results lead us to suggest that the divergent evolution of the colouration of frontal areas is related to species recognition through visual cue assessment in the short-range, when storks form mixed-species flocks in foraging or resting areas.

scholarly journals Comparison of superficial wound documentation using 2D forensic photography, 3D photogrammetry, Botscan© and VR with real-life examination

2021 ◽  
Vol 17 (3) ◽  
pp. 422-430
Author(s):  
Federico Massini ◽  
Lars Ebert ◽  
Garyfalia Ampanozi ◽  
Sabine Franckenberg ◽  
Lena Benz ◽  
...  
Keyword(s):  
Gold Standard ◽  
3D Visualization ◽  
Real Life ◽  
The Body ◽  
Whole Body ◽  
Forest Plot ◽  
Technical Documentation ◽  
Forensic Photography ◽  
Head Mounted Display ◽  
Significant Difference

AbstractEvidence acquisition, interpretation and preservation are essential parts of forensic case work that make a standardized documentation process fundamental. The most commonly used method for the documentation and interpretation of superficial wounds is a combination of two modalities: two-dimensional (2D) photography for evidence preservation and real-life examination for wound analysis. As technologies continue to develop, 2D photography is being enhanced with three-dimensional (3D) documentation technology. In our study, we compared the real-life examination of superficial wounds using four different technical documentation and visualization methods.To test the different methods, a mannequin was equipped with several injury stickers, and then the different methods were applied. A total of 42 artificial injury stickers were documented in regard to orientation, form, color, size, wound borders, wound corners and suspected mechanism of injury for the injury mechanism. As the gold standard, superficial wounds were visually examined by two board-certified forensic pathologists directly on the mannequin. These results were compared to an examination using standard 2D forensic photography; 2D photography using the multicamera system Botscan©, which included predefined viewing positions all around the body; and 3D photogrammetric reconstruction based on images visualized both on screen and in a virtual reality (VR) using a head-mounted display (HMD).The results of the gold standard examination showed that the two forensic pathologists had an inter-reader agreement ranging from 69% for the orientation and 11% for the size of the wounds. A substantial portion of the direct visual documentation showed only a partial overlap, especially for the items of size and color, thereby prohibiting the statistical comparison of these two items. A forest plot analysis of the remaining six items showed no significant difference between the methods. We found that among the forensic pathologists, there was high variability regarding the vocabulary used for the description of wound morphology, which complicated the exact comparison of the two documentations of the same wound.There were no significant differences for any of the four methods compared to the gold standard, thereby challenging the role of real-life examination and 2D photography as the most reliable documentation approaches. Further studies with real injuries are necessary to support our evaluation that technical examination methods involving multicamera systems and 3D visualization for whole-body examination might be a valid alternative in future forensic documentation.

Sign in / Sign up

Export Citation Format

Share Document