Ionizing radiation dosimetry in the absorbed dose range 0.01–50 MGy based on resistance and ESR linewidth measurements of organic conducting crystals

The effect of gamma pre-irradiation of the mixed nickel-magnesium oxide catalyst on the kinetics of hydrogenation of maleic acid in the liquid phase has been studied. The changes of the hydrogenation rate are compared with the changes of the adsorbed amount of the acid and with the changes of the solution composition, activation energy, and absorbed dose of the ionizing radiation. From this comparison and from the interpretation of the experimental data it can be deduced that two types of centers can be distinguished on the surface of the catalyst under study, namely the sorption centres for the acid and hydrogen and the reaction centres.

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Biodistribution and internal radiation dosimetry of a companion diagnostic radiopharmaceutical, [68Ga]PSMA-11, in subcutaneous prostate cancer xenograft model mice

Scientific Reports ◽

10.1038/s41598-021-94684-6 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Su Bin Kim ◽

In Ho Song ◽

Yoo Sung Song ◽

Byung Chul Lee ◽

Arun Gupta ◽

...

Keyword(s):

Prostate Cancer ◽

Radiation Dosimetry ◽

Xenograft Model ◽

Absorbed Dose ◽

Patient Specific ◽

Internal Radiation ◽

Washout Phase ◽

Heterogeneous Tissue ◽

Organ Level ◽

Reported Data

Abstract[68Ga]PSMA-11 is a prostate-specific membrane antigen (PSMA)-targeting radiopharmaceutical for diagnostic PET imaging. Its application can be extended to targeted radionuclide therapy (TRT). In this study, we characterize the biodistribution and pharmacokinetics of [68Ga]PSMA-11 in PSMA-positive and negative (22Rv1 and PC3, respectively) tumor-bearing mice and subsequently estimated its internal radiation dosimetry via voxel-level dosimetry using a dedicated Monte Carlo simulation to evaluate the absorbed dose in the tumor directly. Consequently, this approach overcomes the drawbacks of the conventional organ-level (or phantom-based) method. The kidneys and urinary bladder both showed substantial accumulation of [68Ga]PSMA-11 without exhibiting a washout phase during the study. For the tumor, a peak concentration of 4.5 ± 0.7 %ID/g occurred 90 min after [68Ga]PSMA-11 injection. The voxel- and organ-level methods both determined that the highest absorbed dose occurred in the kidneys (0.209 ± 0.005 Gy/MBq and 0.492 ± 0.059 Gy/MBq, respectively). Using voxel-level dosimetry, the absorbed dose in the tumor was estimated as 0.024 ± 0.003 Gy/MBq. The biodistribution and pharmacokinetics of [68Ga]PSMA-11 in various organs of subcutaneous prostate cancer xenograft model mice were consistent with reported data for prostate cancer patients. Therefore, our data supports the use of voxel-level dosimetry in TRT to deliver personalized dosimetry considering patient-specific heterogeneous tissue compositions and activity distributions.

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Study of Afterglow and Thermoluminescence Properties of Synthetic Opal-C Nanoparticles for In Vivo Dosimetry Applications

MRS Proceedings ◽

10.1557/opl.2013.205 ◽

2013 ◽

Vol 1530 ◽

Author(s):

Marlen Hernández-Ortiz ◽

Laura S. Acosta-Torres ◽

Rodolfo Bernal ◽

Catalina Cruz-Vázquez ◽

Víctor M. Castaño

Keyword(s):

Radiation Dosimetry ◽

Dose Range ◽

Beta Particle ◽

In Vivo Dosimetry ◽

Synthetic Opal ◽

Genotoxic Effects ◽

Stöber Method ◽

Particle Irradiation ◽

The Stöber Method

ABSTRACTOpal particles, with diameter ca. 80 nm, were synthesized by the Stöber method. Samples were exposed to 100 Gy of beta particle irradiation and its thermoluminescence (TL) emission was recorded. TL response presents good reproducibility, standard deviation 1 %. The glow curve displays two TL peaks 86 and 400 °C and the afterglow (AG) phenomenon is observed immediately after irradiation (< 150°C). The synthetic opal-C exhibits a linear dependence of AG response as function of dose from 0.25 to 8 Gy. This dose range is of interest for personal and clinical dosimetry. Moreover, a previous study indicates that cytotoxic and genotoxic effects caused by opal nanoparticles, did not induce unrepairable DNA damage neither a cellular harm. Therefore, our results show synthetic opal-C is a material useful for in vivo radiation dosimetry.

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A comparison of in-air and in-water calibration of a dosimetry system used for radiation dose assessment in cancer therapy

Nuclear Technology and Radiation Protection ◽

10.2298/ntrp1001051a ◽

2010 ◽

Vol 25 (1) ◽

pp. 51-54 ◽

Cited By ~ 2

Author(s):

Waheed Arshed ◽

Khalid Mahmood ◽

Ikramullah Qazi ◽

Asad Ullah ◽

Perveen Akhter ◽

...

Keyword(s):

Radiation Dosimetry ◽

Absorbed Dose ◽

Dose Assessment ◽

Dose Delivery ◽

Air Kerma ◽

Tissue Equivalent ◽

Dosimetry System ◽

Irradiation Geometry ◽

Radiation Dose Assessment ◽

Absorbed Dose To Water

An accurate calibration of the therapy level radiation dosimetry system has a pivotal role in the accuracy of dose delivery to cancer patients. The two methods used for obtaining a tissue equivalent calibration of the system: air kerma calibration and its conversion to a tissue equivalent value (absorbed dose to water) and direct calibration of the system in a water phantom, have been compared for identical irradiation geometry. It was found that the deviation between the two methods remained within a range of 0% to ?1.7% for the PTW UNIDOS dosimetry system. This means that although the recommended method is in-water calibration, under exceptional circumstances, in-air calibration may be used as well.

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Ionization Dosimetry Principles for Conventional and Laser-Driven Clinical Particle Beams

International Journal of Women’s Health Care ◽

10.33140/ijwhc/03/02/00004 ◽

2018 ◽

Vol 3 (2) ◽

Keyword(s):

Ionizing Radiation ◽

Heavy Particle ◽

Absorbed Dose ◽

High Energy ◽

Particle Energy ◽

Particle Accelerators ◽

Carbon Ions ◽

Particle Beams ◽

Radiation Fields ◽

Number Of Particles

In this paper after mentioning the clinical radiation fields of 20 keV-450 MeV/u, they are characterized by the number of particles and their energy. Particle energy is the quantity that determines radiation penetration at the depth at which the tumor is situated (Fig. 1). The number of particles (or beam intensity) is the second major quantity that assures the administration of the absorbed dose in the tumor. The first application shows the radiation levels planned for various radiation fields. Prior to interacting with the medium, the intensity (or energy fluence rate) allows the determination of energy density, energy, power and relativistic force. In the interaction process, it determines the absorbed dose, kerma and exposure. Non-ionizing radiations in the EM spectrum are used as negative energy waves to accelerate particles charged into special installations called particle accelerators. The particles extracted from the accelerator are the source of the corpuscular radiation for high-energy radiotherapy. Of these, light particle beams (electrons and photons) for radiotherapy are generated by betatron, linac, microtron, and synchrotron and heavy particle beams (protons and heavy ions) are generated by cyclotron, isochronous cyclotron, synchro-cyclotron and synchrotron. The ionization dosimetry method used is the ionization chamber for both indirectly ionizing radiation (photons and neutrons) and for directly ionizing radiation (electrons, protons and carbon ions). Because the necessary energies for hadrons therapy are relatively high, 50-250 MeV for protons and 100-450 MeV/u for carbon ions, the alternative to replace non-ionizing radiation with relativistic laser radiation for generating clinical corpuscular radiation through radiation pressure acceleration mechanism (RPA) is presented.

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Gamma-radiation induced damage of proteins in the thick fraction of egg white

Journal of the Serbian Chemical Society ◽

10.2298/jsc0511255v ◽

2005 ◽

Vol 70 (11) ◽

pp. 1255-1262 ◽

Cited By ~ 6

Author(s):

Marija Vuckovic ◽

Marija Radojcic ◽

Bratoljub Milosavljevic

Keyword(s):

Ionizing Radiation ◽

Gel Electrophoresis ◽

Dose Range ◽

Polyacrylamide Gel Electrophoresis ◽

Egg White ◽

Oh Radical ◽

Low Doses ◽

Gel Structure ◽

Exclusion Chromatography ◽

Saturated Sample

The thick fraction of egg white saturated with either N2O or Ar was irradiated in the dose range 1.5-45 kGy at 60Co gamma source. The gel structure decomposition and other processes accompanied with changes in protein molecular mass were followed by Sephadex G-200 exclusion chromatography, denaturing SDS-polyacrylamide gel electrophoresis, viscosity and turbidity measurements. The complex behavior of viscosity was observed in the N2O saturated sample (where the hydrated electron was converted into the OH radical); the initial abrupt decrease that gradually slows down reaching the minimum at 12 kGy (?min = 2.7 mPa s) followed by the slow rise was measured. The Ar saturated sample ([eaq-]?[OH]) showed both the significantly faster initial decrease and lower viscosity minimum (?min = 2.2 mPa s). The combined Sephadex G-200 exclusion chromatography and denaturing SDS-polyacrylamide gel electrophoresis data revealed that the three-dimensional egg white (hydrated) gel structure was (efficiently) decomposed even in the N2O saturated sample. The protein scission was detected in the entire dose range studied, while the protein agglomeration is not noticed at low doses (around 1.5 kGy); however, it dominates at higher doses. In the highest dose region studied, the loss of structure in SDS-PAGE chromatograms indicates that the agglomerates are formed from protein fragments rather than from intact proteins. The continuous linear increase in turbidity was measured. The results obtained indicate that ionizing radiation causes the breakdown of the protein network of the thick fraction of egg white via the reduction of S-S bridges by the hydrated electron and the protein fragmentation due to the direct action of ionizing radiation. The protein agglomeration is initiated by the reaction of the OH radical; its inefficiency at low doses is attributed to the glucose antioxidant properties and radical immobility. .

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Radiation physics, biology, and protection

Cardiovascular Computed Tomography ◽

10.1093/med/9780198809272.003.0005 ◽

2019 ◽

pp. 45-68

Keyword(s):

Ionizing Radiation ◽

Radiation Dosimetry ◽

Biological Effects ◽

Patient Dose ◽

Radiation Doses ◽

X Rays ◽

Radiation Physics

This chapter describes the interactions of X-rays with matter, the biological effects of ionizing radiation (including estimated dose thresholds), the science behind radiation dosimetry, and principles of protection of people and the environment. It goes on to describe patient dose according to scanner design, scan parameters, and methods to manage and optimize radiation doses.

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

Materials Science Forum ◽

10.4028/www.scientific.net/msf.992.403 ◽

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.

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Effect of High-Intensity X-Radiation on the A Group Fibers of the Frog's Sciatic Nerve

American Journal of Physiology-Legacy Content ◽

10.1152/ajplegacy.1956.184.2.333 ◽

1956 ◽

Vol 184 (2) ◽

pp. 333-337 ◽

Cited By ~ 8

Author(s):

Herbert B. Gerstner

Keyword(s):

Sciatic Nerve ◽

Ionizing Radiation ◽

Action Potential ◽

Rise Time ◽

High Intensity ◽

Dose Range ◽

Monophasic Action Potential ◽

Potential Amplitude ◽

Complete Failure ◽

Sciatic Nerves

Isolated sciatic nerves of bullfrogs received x-radiation at a dose rate of 9 kr/min. Prior to and following exposure, the monophasic action potential was recorded. In alpha fibers, doses between 75 kr and 200 kr caused a decrease in conduction velocity, an increase in the rise time of the action potential, and an elevated rheobase with shortened chronaxie; the potential amplitude was not obviously affected. In the dose range above 200 kr, the potential amplitude declined rapidly and complete failure of function occurred at about 300 kr. Beta fibers closely resembled alpha fibers in behavior; however, they appeared to be somewhat more radioresistant than a portion of the alpha subdivision. Gamma fibers seemed to be most susceptible to ionizing radiation; their potential disappeared at doses between 150 kr and 200 kr.

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Dosimetric evaluation of methyl red radiochromic film for radiation processing

Pigment & Resin Technology ◽

10.1108/prt-02-2020-0008 ◽

2020 ◽

Vol ahead-of-print (ahead-of-print) ◽

Author(s):

Awad AL Zahrany ◽

Khalid Rabaeh ◽

Molham Eyadeh ◽

Ahmed Basfar

Keyword(s):

Gamma Ray ◽

Dose Range ◽

Absorbed Dose ◽

Radiochromic Film ◽

High Dose ◽

Methyl Red ◽

Radiation Processing ◽

Content Type ◽

The Stability ◽

The Impact

Purpose The purpose of this paper is to present a radiochromic film dosimeter containing polyvinyl alcohol (PVA) matrix and various concentrations of methyl red (MR) dye for high dose measurements. Design/methodology/approach The MR-PVA films were exposed to irradiation up to 60 kGy using 60Co source of gamma ray. The ultraviolet and visible regions (UV/VIS) spectrophotometry were used to examine the optical density of pre-and post-irradiated dosimeters at 424 nm. Findings The dose sensitivity of MR-PVA films increases significantly with increasing MR dye concentrations in the dose range of 5 to 60 kGy. The impact of relative humidity, irradiation temperature, dose rate and the stability of the films has been analyzed. The overall uncertainty of the MR-PVA film dosimeter is 6.12% (Double Standard-deviation, 95% confidence level). Practical implications It was found that the MR-PVA films may be used as high dose dosimeter with an acceptable overall uncertainty in routine industrial radiation processing. Originality/value The color bleaching of irradiated MR-PVA films in terms of specific absorbance curves increases significantly with increasing absorbed dose up to 60 kGy.

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