A new extrapolation chamber is described, which is used as absolute standard for the determination of the absorbed beta radiation dose. The construction simulates a semi-infinite phantom and the absorbed dose to tissue was determined in tissue equivalent ...
National Technical Information Service (NTIS)
... source in water and in two aluminum and water mixtures. ... By use of experimentally determined counting efficiencies, absolute saturation activities ...
DTIC Science & Technology
The absolute measurements of main dosimetric parameters in the /sup 60/Co field of ROKUS irradiation device are performed in order to create a standard irradiation field for calibration of medical dosemeters. The measurements were made by means of tissue-...
... AD0822914. Title : ABSOLUTE DOSE MEASUREMENTS ON A MEGACURIE CO-60 SOURCE BY MEANS OF CALORIMETRY. ...
Studies were performed for thc determination of radiation doses absorbed in matter, for electron beams from Van-de-Graaff-type accelerators. For absolute measurements both depth dose'' and calorimetric methods were used, and for secondary or routine dose measurements ...
Energy Citations Database
A series of scoping calculations has been undertaken to evaluate the absolute and relative contributions of different radionuclides and exposure pathways to doses that may have been received by individuals living in the vicinity of the Hanford Site. This ...
A series of scoping calculations has been undertaken to evaluate the absolute and relative contribution of different radionuclides and exposure pathways to doses that may have been received by individuals living in the vicinity of the Hanford site. This s...
A method for absolute dose rate determinations in the range of 10/sup 7/ rad (Si) s/sup -/1 to greater than 10/sup 1/0 rad (Si) s/sup -/1 is reported here. The method is useful in determining the simultaneous dose rate delivered to a device under test which is small enough that it does not ...
... Title : DETERMINATION AND APPLICATION OF ABSOLUTE TRANSITION PROBABILITIES AND LIFETIMES OF ATOMS, MOLECULES, AND IONS ...
When establishing the permissible levels of radiation during prolonged space flights one should consider not only the absolute risk attributed to radiation, but also the relative risk. The latter is determined by the ratio of frequencies of the consequenc...
Photon and electron dosimetry equipment and procedures are described. Radiation sources; primary standards for photon radiation in air; ionization chamber standards for water phantoms; chemical dosimetry; absolute determination of absorbed dose; type test...
Twelve wildlife toxicology laboratories participated in an interlaboratory survey of cholinesterase (ChE) assays to determine comparability of absolute ChE values and estimates of ChE inhibition from organophosphorus insecticide-dosed birds and to examine the type and consistency...
EPA Science Inventory
The absolute dose rate around beta sources for intravascular brachytherapy was measured with thin thermoluminescent (TL) dosimeters and radiochromic film. The calibration of these dosimeters was performed at the dose maximum in a 6 MeV electron beam of a linear accelerator. Compared to the values given by the manufacturers, higher ...
PubMed
It is argued that there should be an agreement as to what conventions to use in determining absolute
NASA Technical Reports Server (NTRS)
The irradiation of blood before transfusion into immunosuppressed patients is an increasingly common technique used to prevent graft-versus-host disease. A technical procedure is described for the calibration of blood irradiators, including the determination of absolute dose rate and relative dose distribution over ...
Dose in radiation therapy is traditionally reported as the water-equivalent dose, or dose to water. Monte Carlo dose calculations report dose to medium and thus a methodology is needed to convert dose to medium into dose to water (or vice versa) for ...
NASA Astrophysics Data System (ADS)
Terbutaline sulfate (4 X 0.250 mg) was given to 11 healthy volunteers by inhalation from a metered dose inhaler (MDI), with and without oral administration of a charcoal slurry. Before the inhalations, the adsorbing capacity of the charcoal slurry was tested. Deuterated terbutaline, 0.125 mg, was given intravenously at the same time as the test doses. The ...
ObjectiveThe objectives of the study were to determine the absolute bioavailability of fentanyl from fentanyl buccal soluble film, estimate the percentage of a fentanyl dose absorbed through the buccal mucosa, and compare the bioavailability of equivalent doses administered either as single or multiple ...
PubMed Central
The authors have evaluated the accuracy, in absolute and relative dose measurements, of the Gafchromic EBT film in pulsed high-energy electron beams. Typically, the electron beams used in radiotherapy have a dose-per-pulse value of less than 0.1 mGy/pulse. However, very high dose-per-pulse electron beams are ...
Presented are the results of an investigation of the dose-response relationship for the yield of chromosome aberrations in peripheral blood lymphocytes of persons with some hereditary diseases which represent the high risk group with respect to the increased incidence of malignant tumors and decreased life span. Despite substantially different absolute ...
A series of scoping calculations has been undertaken to evaluate the absolute and relative contributions of different radionuclides and exposure pathways to doses that may have been received by individuals living in the vicinity of the Hanford Site. This scoping calculation (Calculation 004) examined the contributions of numerous radionuclides to ...
... ADA286670. Title : Absolute Determination of the Acceleration of Gravity at the All-Union Scientific Research Institute of Metrology,. ...
... Title : Absolute Determination of Elastic Constants and Stresses from Ultrasonic Group Velocity Data,. Corporate Author : ...
The aim of this study is to develop a model which computes exit dose values from transmission dose data obtained during patient treatment with an electronic portal imaging device (EPID). The proposed model convolves the primary dose distribution, derived from transmission dose distributions at large air gaps, with ...
AimsTo determine the absolute bioavailability, dose proportionality and the effects of food on the pharmacokinetics of single oral doses of sildenafil citrate.MethodsThree open-label, randomized crossover studies were conducted in healthy male subjects. Absolute bioavailability was ...
The use of the thermoluminescence method for dose measurements after Sr/ sup 90/-incorporation was tested in a biological experiment using rats. There is a linear relation between the administered Sr/sup 90/-dose and the radiation dose measured in the abdomen of the rat with a CaF/sub 2/dosimeter. The ...
Intensity modulated radiotherapy (IMRT) has become a treatment of choice in many oncological institutions. Small fields or beamlets with sizes of 1 to 5 cm2 are now routinely used in IMRT delivery. Therefore small ionization chambers (IC) with sensitive volumes <=0.1 cm3are generally used for dose verification of an IMRT treatment. The measurement conditions during ...
The dose-response characteristics were analysed for late skin telangiectasia in patients for 1, 2 and 5 fractions per week and 3 to 4 dose levels per schedule. Altogether 286 fields were used. Skin telangiectasia was scored on an arbitrary scale and dose-response analysis was performed at 10 year's follow-up for various degrees of ...
Deferasirox is a novel iron chelator formulated as tablets for dispersion (suspension) for once-a-day oral administration. The current study evaluated the absolute bioavailability of a single 375-mg oral dose of deferasirox administered in the form of tablets compared with a 130-mg intravenous infusion of deferasirox. Since this was a first-in-man study ...
The treatment of uveal melanoma with proton radiotherapy has provided excellent clinical outcomes. However, contemporary treatment planning systems use simplistic dose algorithms that limit the accuracy of relative dose distributions. Further, absolute predictions of absorbed dose per monitor unit are not yet ...
The prescribed dose in radiation therapy has to be converted into machine monitor units for patient treatment. This is done routinely for each spread-out Bragg peak (SOBP) field either by calibration measurements, by using analytical algorithms or by relying on empirical data. At the Northeast Proton Therapy Center, a monitor unit corresponds to a fixed amount of charge ...
A series of scoping calculations has been undertaken to evaluate the absolute and relative contribution of different radionuclides and exposure pathways to doses that may have been received by individuals living in the vicinity of the Hanford site. This scoping calculation (Calculation 005) examined the contributions of numerous parameters to the ...
The acute radiation pneumonitis syndrome is a major complication for patients receiving total thoracic irradiation in a large single dose. Previous studies have evaluated the onset of radiation pneumonitis on the basis of radiation doses calculated assuming unit density tissues. In this report, the incidence of radiation pneumonitis is ...
This test operations procedure (TOP) delineates general test and specific subtest procedure required to determine the technical performance of absolute altimeters. Absolute altimeters which are used to measure vertical separation between the aircraft and ...
We experimentally evaluated the proton beam dose reproducibility, sensitivity, angular dependence and depth-dose relationships for a new Metal Oxide Semiconductor Field Effect Transistor (MOSFET) detector. The detector was fabricated with a thinner oxide layer and was operated at high-bias voltages. In order to accurately measure dose ...
The distribution of neutrons and gamma rays in the irradiation channels of the Rossendorf Research Reactor was measured. Thermal, epithermal, and fast fluxes were determined. The Cd ratio for several channels was also determined. The measurements of absolute values of the thermal and epithermal neutron flux were performed ...
The TM multispectral scanner system was calibrated in an absolute manner before launch. To determine
... Presented in the report are the results of determination of the absolute spectral sensitivity of photographic films developed by Gosniikhimfotoproyekt ...
A human pharmacokinetic study was performed to assess the ability of a microdose to predict the pharmacokinetics of a therapeutic dose of fexofenadine and to determine its absolute oral bioavailability. Fexofenadine was chosen to represent an unmetabolized transporter substrate (P-gP and OATP). Fexofenadine was administered to 6 ...
Current knowledge on the dosimrietry of fast electrons is reviewed. Definitions of absorbed dose, energy dose, and specific dose are presented. Some methods for absolute and relative dose measurements are discussed. Some calculations for detemination of the ...
Up to 48 hours after a single oral dose of 2 ml of rice bran oil containing 2,500 ppm of diphenyl chloride to white rats, approximately 10% of the diphenyl chloride administered was excreted in the feces, however absolutely none was observed in the urine....
Accurate determination of dose-rate constant (lambda) for interstitial brachytherapy sources emitting low-energy photons (< 50 keV) has remained a challenge in radiation dosimetry because of the lack of a suitable absolute dosimeter for accurate measurement of the dose rates near these sources. Indeed, a ...
Accurate determination of dose-rate constant ({lambda}) for interstitial brachytherapy sources emitting low-energy photons (<50 keV) has remained a challenge in radiation dosimetry because of the lack of a suitable absolute dosimeter for accurate measurement of the dose rates near these sources. Indeed, a ...
An isothermal calorimetric method for the measurement of the energy dose absorbed during reactor irradiatrons of substances is described. The dose values are calculated with respect to the geometrical arrangement from the resulting irradiation temperatures with an absolute error of about 20%, and a relative one of a few ...
Lawrence Livermore National Laboratory (LLNL) has emplaced eleven spent nuclear-reactor fuel assemblies in the Climax granite at the Nevada Test Site as part of the DOE Nevada Nuclear-Waste Storage Investigations. One of our objectives is to study radiation effects on the rock. The neutron and gamma-ray doses to the rock have been determined by MORSE-L ...
DOE Information Bridge
A simple procedure is described for the calibration of a shadow shield whole-body monitor to determine the absolute amount of a radioisotope at various body sites of a patient. It is possible to measure the turnover of the isotope in different tissues from day to day, or to compare the uptake of successive doses of isotope at ...
Measurements and analysis of gamma-background radiation spectrum in four different places of Qatar University campus were performed at the energy range 10 keV-3 MeV using hyper pure Ge-detector. The dependence of the detector absolute photopeak efficiency on gamma-ray energies was determined and correction of the data for that was also done. The absorbed ...
A comparison was made of complete hemograms of 417 uranium-mine employees, of which 347 worked mostly underground, with those of 84 hard-coal miners. The experimental group showed consistent relative and absolute lymphocytosis (presumed reactive overcompensation). neutropenia, eosinopenia (in contrast to British and U. S. reports of eosinophilia), erythiopenia, and ...
The concept of integral dose has been introduced in radiotherapy as the expression of a simple physical characteristic to which is bound the whole of the biological effects produced in the entire irradiated system. The clinical value of such a concept finds confirmation in the correlation noted between the integral dose and some systemic or ...
... Accession Number : ADA205041. Title : Implications of Conservation Equations for the Determination of Absolute Velocities. ...
... BASED ON THE CHANGE IN ABSOLUTE INTENSITY OF ... A METHOD FOR DETERMINING THE TEMPERATURE STABILITY OF TRANSPARENT ...
To assess the effect of ionization chamber wall thickness on absolute neutron absorbed dose determinations, measurements were made of the charge collected by an A-150 tissue-equivalent plastic ionization chamber irradiated by a p(66)Be(49) neutron therapy beam as a function of chamber wall thickness both in air and in four different ...
In comparison to laboratory gamma-ray spectroscopy, in situ gamma-ray spectrometry characterizes a much larger volume of material, requires much less time to determine accurate radionuclide concentrations, and minimizes worker dose and the risk of radioactive contamination. However, the main limitation of in situ gamma-ray spectrometry lies in ...
Reversed-phase high-performance liquid chromatography utilizing photodiode array detection is used for the simultaneous determination of caffeine and nine alkaloids from Citrus aurantium (CA) and ephedra (EA) contained in dietary weight loss products. Since the Food and Drug Administration (FDA) ban of EA, manufacturers have substituted CA in their weight loss formulations, ...
This study reports the absorption, dose-linearity and pharmacokinetics of a novel antiangiogenic agent KR-31831 in rats after i.v. and oral administration at doses of 5, 10 and 25 mg/kg on both occasions. Concentrations of KR-31831 were determined by a validated LC/MS/MS assay method. After i.v. injection, plasma concentration-time ...
A hybrid phantom-embedded extrapolation chamber (PEEC) made of Solid Water(TM) and bone-equivalent material was used for determining absolute dose in a bone-equivalent phantom irradiated with clinical radiation beams (cobalt-60 gamma rays; 6 and 18 MV x-rays; and 9 and 15 MeV electrons). The dose was ...
Purpose: To identify dosimetric variables predictive of acute gastrointestinal (GI) and genitourinary (GU) toxicity and to determine whether hormonal therapy (HT) is independently associated with acute GI and GU toxicity in prostate cancer patients treated with conformal radiotherapy (RT). Methods and Materials: This analysis was performed on 336 patients participating in a ...
Aims: Erythropoietin stimulating agents (ESAs) is an active area of clinical investigation in heart failure (HF) but can cause hypertension and higher hemoglobin concentrations (Hb) that have been associated with adverse outcomes. We evaluated a dosing algorithm and potential confounders' effect on Hb and blood pressure (BP) in a clinical trial. Methods: In an ongoing ...
The physical dose delivered in radio-immunotherapy (RIT) may not, by itself, be a reliable indicator of the likely effectiveness of the treatment. Radiobiological considerations, in particular those relating to the dose-rate, are also very relevant. Dose-rate effects are important in conventional radiotherapy because of their ability ...
This study was first conducted to characterize the intravenous and oral pharmacokinetics of magnolin, a major pharmacologically active ingredient of Magnolia fargesii, at various doses in rats. Magnolin was administered to rats by intravenous injection (0.5, 1 and 2 mg/kg doses) and oral administration (1, 2 and 4 mg/kg doses), and ...
The GAFCHROMIC(�) EBT2 dosimetry film has been studied as a rapid QC/QA tool for 2D dose profile mapping in the BNCT beam at THOR. The pixel values of the EBT2 film image were converted to the 2D dose profile using a dose calibration curve obtained by 6-MV X-ray. The reproducibility of the 2D dose profile ...
Electron beam temperature, {beta}{perpendicular} (= v{perpendicular}/v), is important to control for the development of high dose flash radiographic bremsstrahlung sources. At high voltage (> 5 MV) increasing electron beam temperature has a serious deleterious effect on dose production. The average and time resolved behavior of beam temperature was ...
Pharmacokinetics of ragaglitazar (a novel phenoxazine derivative of aryl propanoic acid), a potent insulin sensitizing and lipid-lowering compound was studied in Wistar rats. A single dose of 1, 3 or 10 mg/kg of ragaglitazar was given orally to male rats (n=4 per dose level) to evaluate dose proportionality. In another study, a single ...
... 4. TITLE AND SUBTITLE P-Vector Method for Determining Absolute Velocity From Hydrographic Data 5a. CONTRACT NUMBER 5b. ...
... ADA480668. Title : P-Vector Method for Determining Absolute Velocity From Hydrographic Data. Descriptive Note : Journal article. ...
A method is described whereby the absolute radiative quantum efficiency of paramagnetic ions in liquids or solids can be determined from photoacoustic measurements. 1 figure.
Intensity modulated radiotherapy (IMRT) provides an improvement in the conformality of radiotherapy dose distributions. Its application to photon radiotherapy for prostate adenocarcinoma is well established. A quality assurance tool for verifying photon IMRT treatment and the potential application of intensity modulation to neutron radiotherapy (IMNRT) to prostate cancer are ...
In this work some dosimetric characteristics of MD-55-2 GafChromic films were studied in a low energy proton beam (21.5 MeV) directly in a water phantom. The nonlinearity of the optical density was quantified by a factor P(lin). A correction factor P(en), that accounts for optical density dependence on the energy, was empirically determined. The effects of detector thickness ...
AimsTo investigate the absolute bioavailability of imidafenacin, a new muscarinic receptor antagonist, a single oral dose of 0.1 mg imidafenacin was compared with an intravenous (i.v.) infusion dose of 0.028 mg of the drug in healthy subjects.MethodsFourteen healthy male subjects, aged 21�45 years, received a single oral ...
The sulphuric acid used for the preparation of the Fricke dosimeter solution may contain trace impurities that can affect the yield of ferric ions. Two methods, pre-irradiation or oxidation with hydrogen peroxide, have been proposed to reduce the influence of these impurities. Fricke users sometimes omit this treatment. In the present work Fricke solutions prepared from six different brands and ...
A method for the production of t-butoxy radicals by the photolysis of t-butyl hypochlorite was employed to determine the absolute rate of combination of t-butoxy radicals at room temperature and to determine the absolute rate of hydrogen atom abstraction ...
The status of absolute gravimetry is discussed. An easily portable apparatus for the absolute determination of the acceleration of gravity is described. Laboratory tests of this instrument indicate that a measurement accuracy of six parts in a billion is achieved. This corresponds to an equivalent height sensitivity of about 2 cm.
To determine the relative importance of factors influencing tumour uptake of antibodies, we used a mathematical model to simulate intravenous injection of substances of varying molecular sizes and tumour-binding affinities at several dose levels. The FACSIMILE program was used to simulate the time course of tumour uptake of the tumour-binding substance by ...
In this study a complete set of dosimetric data is presented for the high dose rate (HDR) source from Amersham used in the Buchler remote afterloading HDR unit. These data have been calculated by means of the Monte Carlo simulation code GEANT taking into account the detailed geometry of the source. Absolute dose rate distributions in ...
Proton beam radiotherapy is an effective and non-invasive treatment for uveal melanoma. Recent research efforts have focused on improving the dosimetric accuracy of treatment planning and overcoming the present limitation of relative analytical dose calculations. Monte Carlo algorithms have been shown to accurately predict dose per monitor unit (D/MU) ...
Dose distributions generated from intensity-modulated-radiation-therapy (IMRT) treatment planning present high dose gradient regions in the boundaries between the target and the surrounding critical organs. Dose accuracy in these areas can be critical, and may affect the treatment. With the increasing use of IMRT in radiotherapy, there ...
In this study, absorbed doses were measured and compared for high-energy electrons (6, 9, 12, 16, and 20 MeV) using International Atomic Energy Agency (IAEA), Technical Reports Series No. 277 (TRS), TRS 381, and TRS 398 dosimetry protocols. Absolute dose measurements were carried out using FC65-G Farmer chamber and Nordic Association ...
In order to sophisticate the radiotherapy high accuracy knowledge of the absorbed dose delivered to the patient is essential The main methods of absolute dosimetry are indicated as follows a Dosimetry by ion chamber b Fricke dosimetry and c Calorimetry The calorimetry is most direct method of dosimetry due to direct measurement of energy deposit in ...
The determination of accurate, quantitative, biokinetic distribution of an internally dispersed radionuclide in humans is important in making realistic radiation absorbed dose estimates, studying biochemical transformations in health and disease, and developing clinical procedures indicative of abnormal functions. In order to collect these data, a ...
AimTo determine the absolute bioavailability of extravascularly administered dexmedetomidine, a novel a2-adrenoceptor agonist, in healthy subjects.MethodsSingle 2 �g kg?1 doses of dexmedetomidine were given intravenously, intramuscularly, perorally and buccally (where the solution is not swallowed) to 12 ...
Reported MOSFET measurements concern mostly external radiotherapy and in vivo dosimetry. In this paper, we apply the technique for absolute dosimetry in the context of HDR brachytherapy using an {sup 192}Ir source. Measured radial dose rate distributions in water for different planes perpendicular to the source axis are presented and special attention is ...
The concept of equivalent uniform dose (EUD) was introduced to provide a method of reporting radiotherapy dose distributions which takes account of the nonlinearity of tissue dose-response, whilst not attempting to make predictions of absolute outcome. The purpose of this investigation was to ...
The increased utilization of x-ray imaging in image-guided radiotherapy has dramatically improved the radiation treatment and the lives of cancer patients. Daily imaging procedures, such as cone-beam computed tomography (CBCT), for patient setup may significantly increase the dose to the patient's normal tissues. This study investigates the dosimetry from a ...
The increased utilization of x-ray imaging in image-guided radiotherapy has dramatically improved the radiation treatment and the lives of cancer patients. Daily imaging procedures, such as cone-beam computed tomography (CBCT), for patient setup may significantly increase the dose to the patient's normal tissues. This study investigates the dosimetry from a kilovoltage (kV) ...
Proton radiation in space will come from both the Van Allen Belt and solar flares. Although the transitory radiation fluxes from these flares contain a variety of particles, the proton componert is chiefly responsible for radiation effects on man. Observations of proton flux after the solar flares of May 10, 1959. and February 23, 1956, were studied to determine the ...
... digital signals can be combined with dose data stored in the microprocessor to determine gamma ray dose rates and neutron and gamma ray doses ...
The electron Monte Carlo (eMC) dose calculation algorithm in Eclipse (Varian Medical Systems) is based on the macro MC method and is able to predict dose distributions for high energy electron beams with high accuracy. However, there are limitations for low energy electron beams. This work aims to improve the accuracy of the dose ...
BackgroundDiabetic type 1 patients are often advised to use dose adjustment guidelines to calculate their doses of insulin. Conventional methods of measuring patients' adherence are not applicable to these cases, because insulin doses are not determined in advance. We propose a method and a number of indicators to ...
Intensity-modulated radiotherapy treatment demands stringent quality assurance and accurate dose determination for delivery of highly conformal dose to the patients. Generally 3D dose distributions obtained from a treatment planning system have to be verified by dosimetric methods. Mainly, a comparison of ...
... the photon yields in the ... Descriptors : *CHEMICAL REACTIONS, *PHOTONS, *CHEMILUMINESCENCE ... LASERS, FLUORINE, YIELD, NITROGEN ...
