Total Risk Management for Low Dose Radiation Exposures

International Nuclear Information System (INIS)

Simic, Z.; Mikulicic, V.; Sterc, D.

2012-01-01

Our civilization is witnessing about century of nuclear age mixed with enormous promises and cataclysmic threats. Nuclear energy seems to encapsulate both potential for pure good and evil or at least we humans are able to perceive that. These images are continuously with us and they are both helping and distracting from making best of nuclear potentials for civilization. Today with nuclear use significantly present and with huge potential to further improve our life with energy and medical use it is of enormous importance to try to have calmed, rational, and objective view on potential risks and certain benefits. Because all use of nuclear energy proved that their immediate risks are negligible (i.e., Three Mile Island and Fukushima) or much smaller than from the other alternatives (i.e., Chernobyl) it seems that the most important issue is the amount of risk from the long term effects to people from exposure to small doses of radiation. A similar issue is present in the increased use of modern computational tomography and other radiation sources use in medicine for examination and therapy. Finally, extreme natural exposures are third such potential risk sources. Definition of low doses varies depending on the way of delivery (i.e., single, multiple or continuous exposures), and for this paper usual dose of 100 mSv is selected as yearly upper amount. There are three very different scientifically supported views on the potential risks from the low doses exposure. The most conservative theory is that all radiation is harmful, and even small increments from background levels (i.e., 2-3 mSv) present additional risk. This view is called linear no threshold theory (LNT) and it is accepted as a regulatory conservative simple approach which guarantees safety. Risk is derived from the extrapolation of the measured effects of high levels of radiation. Opposite theory to LNT is hormesis which assumes that in fact small doses of radiation are helpful and they are improving our

p-MOSFET total dose dosimeter

Science.gov (United States)

Buehler, Martin G. (Inventor); Blaes, Brent R. (Inventor)

1994-01-01

A p-MOSFET total dose dosimeter where the gate voltage is proportional to the incident radiation dose. It is configured in an n-WELL of a p-BODY substrate. It is operated in the saturation region which is ensured by connecting the gate to the drain. The n-well is connected to zero bias. Current flow from source to drain, rather than from peripheral leakage, is ensured by configuring the device as an edgeless MOSFET where the source completely surrounds the drain. The drain junction is the only junction not connected to zero bias. The MOSFET is connected as part of the feedback loop of an operational amplifier. The operational amplifier holds the drain current fixed at a level which minimizes temperature dependence and also fixes the drain voltage. The sensitivity to radiation is made maximum by operating the MOSFET in the OFF state during radiation soak.

Determination of the total indicative dose in drinking and mineral waters

International Nuclear Information System (INIS)

Flesch, K.; Schulz, H.; Knappik, R.; Koehler, M.

2006-01-01

In Europe and Germany administrative regulations exist for the surveillance of the total indicative dose of water supplied for human consumption. This parameter, which cannot be analyzed directly, has to be calculated using nuclide specific activity concentration and age specific dose conversion factors and consumption rates. Available calculation methods differ regarding the used radionuclides, consumption rates and whether they use age specific dose conversion factors or not. In Germany administrative guidelines for the determination of the total indicative dose are still not available. As they have analyzed a large number of waters in the past, the authors derive a praxis orientated concept for the determination of the total indicative dose which respects radiological, analytical and hydrochemical aspects as well. Finally it is suggested to handle sparkling waters in the same manner as drinking waters. (orig.)

Pulsed total dose damage effect experimental study on EPROM

International Nuclear Information System (INIS)

Luo Yinhong; Yao Zhibin; Zhang Fengqi; Guo Hongxia; Zhang Keying; Wang Yuanming; He Baoping

2011-01-01

Nowadays, memory radiation effect study mainly focus on functionality measurement. Measurable parameters is few in china. According to the present situation, threshold voltage testing method was presented on floating gate EPROM memory. Experimental study of pulsed total dose effect on EPROM threshold voltage was carried out. Damage mechanism was analysed The experiment results showed that memory cell threshold voltage negative shift was caused by pulsed total dose, memory cell threshold voltage shift is basically coincident under steady bias supply and no bias supply. (authors)

Total dose effects on the matching properties of deep submicron MOS transistors

International Nuclear Information System (INIS)

Wang Yuxin; Hu Rongbin; Li Ruzhang; Chen Guangbing; Fu Dongbing; Lu Wu

2014-01-01

Based on 0.18 μm MOS transistors, for the first time, the total dose effects on the matching properties of deep submicron MOS transistors are studied. The experimental results show that the total dose radiation magnifies the mismatch among identically designed MOS transistors. In our experiments, as the radiation total dose rises to 200 krad, the threshold voltage and drain current mismatch percentages of NMOS transistors increase from 0.55% and 1.4% before radiation to 17.4% and 13.5% after radiation, respectively. PMOS transistors seem to be resistant to radiation damage. For all the range of radiation total dose, the threshold voltage and drain current mismatch percentages of PMOS transistors keep under 0.5% and 2.72%, respectively. (semiconductor devices)

Evaluation of accelerated test parameters for CMOS IC total dose hardness prediction

International Nuclear Information System (INIS)

Sogoyan, A.V.; Nikiforov, A.Y.; Chumakov, A.I.

1999-01-01

The approach to accelerated test parameters evaluation is presented in order to predict CMOS IC total dose behavior in variable dose-rate environment. The technique is based on the analytical model of MOSFET parameters total dose degradation. The simple way to estimate model parameter is proposed using IC's input-output MOSFET radiation test results. (authors)

Dose equivalent distributions in the AAEC total body nitrogen facility

International Nuclear Information System (INIS)

Allen, B.J.; Bailey, G.M.; McGregor, B.J.

1985-01-01

The incident neutron dose equivalent in the AAEC total body nitrogen facility is measured by a calibrated remmeter. Dose equivalent rates and distributions are calculated by Monte Carlo techniques which take account of the secondary neutron flux from the collimator. Experiment and calculation are found to be in satisfactory agreement. The effective dose equivalent per exposure is determined by weighting organ doses, and the potential detriment per exposure is calculated from ICRP risk factors

Low-dose-rate total lymphoid irradiation: a new method of rapid immunosuppression

International Nuclear Information System (INIS)

Blum, J.E.; de Silva, S.M.; Rachman, D.B.; Order, S.E.

1988-01-01

Total Lymphoid Irradiation (TLI) has been successful in inducing immunosuppression in experimental and clinical applications. However, both the experimental and clinical utility of TLI are hampered by the prolonged treatment courses required (23 days in rats and 30-60 days in humans). Low-dose-rate TLI has the potential of reducing overall treatment time while achieving comparable immunosuppression. This study examines the immunosuppressive activity and treatment toxicity of conventional-dose-rate (23 days) vs low-dose-rate (2-7 days) TLI. Seven groups of Lewis rats were given TLI with 60Co. One group was treated at conventional-dose-rates (80-110 cGy/min) and received 3400 cGy in 17 fractions over 23 days. Six groups were treated at low-dose-rate (7 cGy/min) and received total doses of 800, 1200, 1800, 2400, 3000, and 3400 cGy over 2-7 days. Rats treated at conventional-dose-rates over 23 days and at low-dose-rate over 2-7 days tolerated radiation with minimal toxicity. The level of immunosuppression was tested using allogeneic (Brown-Norway) skin graft survival. Control animals retained allogeneic skin grafts for a mean of 14 days (range 8-21 days). Conventional-dose-rate treated animals (3400 cGy in 23 days) kept their grafts 60 days (range 50-66 days) (p less than .001). Low-dose-rate treated rats (800 to 3400 cGy total dose over 2-7 days) also had prolongation of allogeneic graft survival times following TLI with a dose-response curve established. The graft survival time for the 3400 cGy low-dose-rate group (66 days, range 52-78 days) was not significantly different from the 3400 cGy conventional-dose-rate group (p less than 0.10). When the total dose given was equivalent, low-dose-rate TLI demonstrated an advantage of reduced overall treatment time compared to conventional-dose-rate TLI (7 days vs. 23 days) with no increase in toxicity

New Insights into Fully-Depleted SOI Transistor Response During Total Dose Irradiation

International Nuclear Information System (INIS)

Burns, J.A.; Dodd, P.E.; Keast, C.L.; Schwank, J.R.; Shaneyfelt, M.R.; Wyatt, P.W.

1999-01-01

Worst-case bias configuration for total-dose testing fully-depleted SOI transistors was found to be process dependent. No evidence was found for total-dose induced snap back. These results have implications for hardness assurance testing

Total dose effects on ATLAS-SCT front-end electronics

CERN Document Server

Ullán, M; Dubbs, T; Grillo, A A; Spencer, E; Seiden, A; Spieler, H; Gilchriese, M G D; Lozano, M

2002-01-01

Low dose rate effects (LDRE) in bipolar technologies complicate the hardness assurance testing for high energy physics applications. The damage produced in the ICs in the real experiment can be underestimated if fast irradiations are carried out, while experiments done at the real dose rate are usually unpractical due to the still high total doses involved. In this work the sensitivity to LDRE of two bipolar technologies proposed for the ATLAS-SCT experiment at CERN is evaluated, finding one of them free of those effects. (12 refs).

Total dose meter development

International Nuclear Information System (INIS)

Brackenbush, L.W.

1986-09-01

This report describes an alarming ''pocket'' monitor/dosimeter, based on a tissue-equivalent proportional counter, that measure both neutron and gamma dose and determines dose equivalent for the mixed radiation field. This report details the operation of the device and provides information on: the necessity for a device to measure dose equivalent in mixed radiation fields; the mathematical theory required to determine dose equivalent from tissue equivalent proportional; the detailed electronic circuits required; the algorithms required in the microprocessor used to calculate dose equivalent; the features of the instrument; program accomplishments and future plans

Single event effects and total ionizing dose effects of typical VDMOSFET devices

International Nuclear Information System (INIS)

Lou Jianshe; Cai Nan; Liu Jiaxin; Wu Qinzhi; Wang Jia

2012-01-01

In this work, single event effects and total ionizing dose effects of typical VDMOSFET irradiated by 60 Co γ-rays and 252 Cf source were studied. The single event burnout and single event gate rupture (SEB/SEGR) effects were investigated, and the relationship between drain-source breakdown voltage and ionizing dose was obtained. The results showed that the VDMOSFET devices were sensitive to SEB and SEGR, and measures to improve their resistance to SEB and SEGR should be considered seriously for their space applications. The drain-source breakdown voltage was sensitive to total ionizing dose effects as the threshold voltage. In assessing the devices' resistance to the total ionizing dose effects, both the threshold voltage and the drain-source breakdown voltage should be taken into account. (authors)

Pocket total dose meter

International Nuclear Information System (INIS)

Brackenbush, L.W.; Endres, G.W.R.

1984-10-01

Laboratory measurements have demonstrated that it is possible to simultaneously measure absorbed dose and dose equivalent using a single tissue equivalent proportional counter. Small, pocket sized instruments are being developed to determine dose equivalent as the worker is exposed to mixed field radiation. This paper describes the electronic circuitry and computer algorithms used to determine dose equivalent in these devices

Use of normalized total dose to represent the biological effect of fractionated radiotherapy

Energy Technology Data Exchange (ETDEWEB)

Flickinger, J C; Kalend, A [Pittsburgh University School of Medicine (USA). Department of Radiation Oncology Pittsburg Cancer Institute (USA)

1990-03-01

There are currently a number of radiobiological models to account for the effects of dose fractionation and time. Normalized total dose (NTD) is not another new model but is a previously reported, clinically useful form in which to represent the biological effect, determined by any specific radiobiological dose-fractionation model, of a course of radiation using a single set of standardized, easily understood terminology. The generalized form of NTD reviewed in this paper describes the effect of a course of radiotherapy administered with nonstandard fractionation as the total dose of radiation in Gy that could be administered with a given reference fractionation such as 2 Gy per fraction, 5 fractions per week that would produce an equivalent biological effect (probability of complications or tumor control) as predicted by a given dose-fractionation formula. The use of normalized total dose with several different exponential and linear-quadratic dose-fraction formulas is presented. (author). 51 refs.; 1 fig.; 1 tab.

Use of normalized total dose to represent the biological effect of fractionated radiotherapy

International Nuclear Information System (INIS)

Flickinger, J.C.; Kalend, A.

1990-01-01

There are currently a number of radiobiological models to account for the effects of dose fractionation and time. Normalized total dose (NTD) is not another new model but is a previously reported, clinically useful form in which to represent the biological effect, determined by any specific radiobiological dose-fractionation model, of a course of radiation using a single set of standardized, easily understood terminology. The generalized form of NTD reviewed in this paper describes the effect of a course of radiotherapy administered with nonstandard fractionation as the total dose of radiation in Gy that could be administered with a given reference fractionation such as 2 Gy per fraction, 5 fractions per week that would produce an equivalent biological effect (probability of complications or tumor control) as predicted by a given dose-fractionation formula. The use of normalized total dose with several different exponential and linear-quadratic dose-fraction formulas is presented. (author). 51 refs.; 1 fig.; 1 tab

A method comparison of total and HMW adiponectin: HMW/total adiponectin ratio varies versus total adiponectin, independent of clinical condition.

Science.gov (United States)

van Andel, Merel; Drent, Madeleine L; van Herwaarden, Antonius E; Ackermans, Mariëtte T; Heijboer, Annemieke C

2017-02-01

Total and high-molecular-weight (HMW) adiponectin have been associated with endocrine and cardiovascular pathology. As no gold standard is available, the discussion about biological relevance of isoforms is complicated. In our study we perform a method comparison between two commercially available assays measuring HMW and total adiponectin, in various patient groups, thus contributing further to this discussion. We determined levels of HMW and total adiponectin using assays by Lumipulse® and Millipore® respectively, in 126 patients with different clinical characteristics (n=29 healthy volunteers, n=22 dialysis patients, n=25 elderly with body mass index (BMI) LUMIPULSE ∗0.5-0.9=total adiponectin MILLIPORE , albeit with significant deviation from linearity (p<0.001). Pearson's correlation was R=0.987 (p=0.000). No significant differences between patient groups were observed (p=0.190). The HMW/total adiponectin ratio varies with total adiponectin concentration independent of clinical conditions studied. Our results imply that total and HMW adiponectin have similar utility when assessing adiponectin levels in blood, as the ratio is independent of clinical condition. Copyright © 2016 Elsevier B.V. All rights reserved.

Dose calculation method with 60-cobalt gamma rays in total body irradiation

International Nuclear Information System (INIS)

Scaff, Luiz Alberto Malaguti

2001-01-01

Physical factors associated to total body irradiation using 60 Co gamma rays beams, were studied in order to develop a calculation method of the dose distribution that could be reproduced in any radiotherapy center with good precision. The method is based on considering total body irradiation as a large and irregular field with heterogeneities. To calculate doses, or doses rates, of each area of interest (head, thorax, thigh, etc.), scattered radiation is determined. It was observed that if dismagnified fields were considered to calculate the scattered radiation, the resulting values could be applied on a projection to the real size to obtain the values for dose rate calculations. In a parallel work it was determined the variation of the dose rate in the air, for the distance of treatment, and for points out of the central axis. This confirm that the use of the inverse square law is not valid. An attenuation curve for a broad beam was also determined in order to allow the use of absorbers. In this work all the adapted formulas for dose rate calculations in several areas of the body are described, as well time/dose templates sheets for total body irradiation. The in vivo dosimetry, proved that either experimental or calculated dose rate values (achieved by the proposed method), did not have significant discrepancies. (author)

On different types of hereditable changes in the viability of Amoeba protens cells x-irradiated with varying doses

International Nuclear Information System (INIS)

Bychkovskaya, I.B.; Ochinskaya, G.K.; Erokhina, G.M.

1976-01-01

Qualitatively different types of cells lethality have been observed in the posterity of amoebae irradiated with doses ranging from 0.5 to 40 kR and from 60 to 120 kR. At doses of 0.5 to 40 kR, a certain part of cells in a population dies, and the effect is characterized by stability and independency of a radiation dose, hereditable radiation damage of all the cells in the population, and by the fact that it might be caused not only by a derect action of radiation but also by a preirradiated culture medium. Higher doses (60 to 120 kR) cause a more drastic but sell stable effect. Depending on a dose value, a varying percentage of cells has shown the effect not being caused by the action of the preirradiated medium. The data obtained indicate that there are different mechanisms of hereditable radiation damages to cells caused by varying radiation doses

Calculation of midplane dose for total body irradiation from entrance and exit dose MOSFET measurements.

Science.gov (United States)

Satory, P R

2012-03-01

This work is the development of a MOSFET based surface in vivo dosimetry system for total body irradiation patients treated with bilateral extended SSD beams using PMMA missing tissue compensators adjacent to the patient. An empirical formula to calculate midplane dose from MOSFET measured entrance and exit doses has been derived. The dependency of surface dose on the air-gap between the spoiler and the surface was investigated by suspending a spoiler above a water phantom, and taking percentage depth dose measurements (PDD). Exit and entrances doses were measured with MOSFETs in conjunction with midplane doses measured with an ion chamber. The entrance and exit doses were combined using an exponential attenuation formula to give an estimate of midplane dose and were compared to the midplane ion chamber measurement for a range of phantom thicknesses. Having a maximum PDD at the surface simplifies the prediction of midplane dose, which is achieved by ensuring that the air gap between the compensator and the surface is less than 10 cm. The comparison of estimated midplane dose and measured midplane dose showed no dependence on phantom thickness and an average correction factor of 0.88 was found. If the missing tissue compensators are kept within 10 cm of the patient then MOSFET measurements of entrance and exit dose can predict the midplane dose for the patient.

Dose/dose-rate responses of shrimp larvae to UV-B radiation

International Nuclear Information System (INIS)

Damkaer, D.M.

1981-01-01

Previous work indicated dose-rate thresholds in the effects of UV-B on the near-surface larvae of three shrimp species. Additional observations suggest that the total dose response varies with dose-rate. Below 0.002 Wm -2 sub([DNA]) irradiance no significant effect is noted in activity, development, or survival. Beyond that dose-rate threshold, shrimp larvae are significantly affected if the total dose exceeds about 85 Jm -2 sub([DNA]). Predictions cannot be made without both the dose-rate and the dose. These dose/dose-rate thresholds are compared to four-year mean dose/dose-rate solar UV-B irradiances at the experimental site, measured at the surface and calculated for 1 m depth. The probability that the shrimp larvae would receive lethal irradiance is low for the first half of the season of surface occurrence, even with a 44% increase in damaging UV radiation. (orig.)

Dose/dose-rate responses of shrimp larvae to UV-B radiation

Energy Technology Data Exchange (ETDEWEB)

Damkaer, D.M.; Dey, D.B.; Heron, G.A.

1981-01-01

Previous work indicated dose-rate thresholds in the effects of UV-B on the near-surface larvae of three shrimp species. Additional observations suggest that the total dose response varies with dose-rate. Below 0.002 Wm/sup -2/sub((DNA)) irradiance no significant effect is noted in activity, development, or survival. Beyond that dose-rate threshold, shrimp larvae are significantly affected if the total dose exceeds about 85 Jm/sup -2/sub((DNA)). Predictions cannot be made without both the dose-rate and the dose. These dose/dose-rate thresholds are compared to four-year mean dose/dose-rate solar UV-B irradiances at the experimental site, measured at the surface and calculated for 1 m depth. The probability that the shrimp larvae would receive lethal irradiance is low for the first half of the season of surface occurrence, even with a 44% increase in damaging UV radiation.

An experimental study on total dose effects in SRAM-based FPGAs

International Nuclear Information System (INIS)

Yao Zhibin; He Baoping; Zhang Fengqi; Guo Hongxia; Luo Yinhong; Wang Yuanming; Zhang Keying

2009-01-01

In order to study testing methods and find sensitive parameters in total dose effects on SRAM-based FPGA, XC2S100 chips were irradiated by 60 Co γ-rays and tested with two test circuit designs. By analyzing the experimental results, the test flow of configuration RAM and bock RAM was given, and the most sensitive parameter was obtained. The results will be a solid foundation for establishing test specification and evaluation methods of total dose effects on SRAM-based FPGAs. (authors)

Application of combined TLD and CR-39 PNTD method for measurement of total dose and dose equivalent on ISS

International Nuclear Information System (INIS)

Benton, E.R.; Deme, S.; Apathy, I.

2006-01-01

To date, no single passive detector has been found that measures dose equivalent from ionizing radiation exposure in low-Earth orbit. We have developed the I.S.S. Passive Dosimetry System (P.D.S.), utilizing a combination of TLD in the form of the self-contained Pille TLD system and stacks of CR-39 plastic nuclear track detector (P.N.T.D.) oriented in three mutually orthogonal directions, to measure total dose and dose equivalent aboard the International Space Station (I.S.S.). The Pille TLD system, consisting on an on board reader and a large number of Ca 2 SO 4 :Dy TLD cells, is used to measure absorbed dose. The Pille TLD cells are read out and annealed by the I.S.S. crew on orbit, such that dose information for any time period or condition, e.g. for E.V.A. or following a solar particle event, is immediately available. Near-tissue equivalent CR-39 P.N.T.D. provides Let spectrum, dose, and dose equivalent from charged particles of LET ∞ H 2 O ≥ 10 keV/μm, including the secondaries produced in interactions with high-energy neutrons. Dose information from CR-39 P.N.T.D. is used to correct the absorbed dose component ≥ 10 keV/μm measured in TLD to obtain total dose. Dose equivalent from CR-39 P.N.T.D. is combined with the dose component <10 keV/μm measured in TLD to obtain total dose equivalent. Dose rates ranging from 165 to 250 μGy/day and dose equivalent rates ranging from 340 to 450 μSv/day were measured aboard I.S.S. during the Expedition 2 mission in 2001. Results from the P.D.S. are consistent with those from other passive detectors tested as part of the ground-based I.C.C.H.I.B.A.N. intercomparison of space radiation dosimeters. (authors)

Effect of γ-dose rate and total dose interrelation on the polymeric hydrogel: A novel injectable male contraceptive

International Nuclear Information System (INIS)

Jha, Pradeep K.; Jha, Rakhi; Gupta, B.L.; Guha, Sujoy K.

2010-01-01

Functional necessity to use a particular range of dose rate and total dose of γ-initiated polymerization to manufacture a novel polymeric hydrogel RISUG (reversible inhibition of sperm under guidance) made of styrene maleic anhydride (SMA) dissolved in dimethyl sulphoxide (DMSO), for its broad biomedical application explores new dimension of research. The present work involves 16 irradiated samples. They were tested by fourier transform infrared spectroscopy, matrix assisted laser desorption/ionization-TOF, field emission scanning electron microscopy, high resolution transmission electron microscopy, etc. to see the interrelation effect of gamma dose rates (8.25, 17.29, 20.01 and 25.00 Gy/min) and four sets of doses (1.8, 2.0, 2.2 and 2.4 kGy) on the molecular weight, molecular weight distribution and porosity analysis of the biopolymeric drug RISUG. The results of randomized experiment indicated that a range of 18-24 Gy/min γ-dose rate and 2.0-2.4 kGy γ-total doses is suitable for the desirable in vivo performance of the contraceptive copolymer.

Prediction of midline dose from entrance ad exit dose using OSLD measurements for total irradiation

Energy Technology Data Exchange (ETDEWEB)

Choi, Chang Heon; Park, Jong Min; Park, So Yeon; Chun, Min Soo; Han, Ji Hye; Cho, Jin Dong; Kim, Jung In [Dept. of Radiation Oncology, Seoul National University Hospital, Seoul (Korea, Republic of)

2017-06-15

This study aims to predict the midline dose based on the entrance and exit doses from optically stimulated luminescence detector (OSLD) measurements for total body irradiation (TBI). For TBI treatment, beam data sets were measured for 6 MV and 15 MV beams. To evaluate the tissue lateral effect of various thicknesses, the midline dose and peak dose were measured using a solid water phantom (SWP) and ion chamber. The entrance and exit doses were measured using OSLDs. OSLDs were attached onto the central beam axis at the entrance and exit surfaces of the phantom. The predicted midline dose was evaluated as the sum of the entrance and exit doses by OSLD measurement. The ratio of the entrance dose to the exit dose was evaluated at various thicknesses. The ratio of the peak dose to the midline dose was 1.12 for a 30 cm thick SWP at both energies. When the patient thickness is greater than 30 cm, the 15 MV should be used to ensure dose homogeneity. The ratio of the entrance dose to the exit dose was less than 1.0 for thicknesses of less than 30 cm and 40 cm at 6 MV and 15 MV, respectively. Therefore, the predicted midline dose can be underestimated for thinner body. At 15 MV, the ratios were approximately 1.06 for a thickness of 50 cm. In cases where adult patients are treated with the 15 MV photon beam, it is possible for the predicted midline dose to be overestimated for parts of the body with a thickness of 50 cm or greater. The predicted midline dose and OSLD-measured midline dose depend on the phantom thickness. For in-vivo dosimetry of TBI, the measurement dose should be corrected in order to accurately predict the midline dose.

The Sandia total-dose estimator: SANDOSE description and user guide

International Nuclear Information System (INIS)

Turner, C.D.

1995-02-01

The SANdia total-DOSe Estimator (SANDOSE) is used to estimate total radiation dose to a (BRL-CAT) solid model, SANDOSE uses the mass-sectoring technique to sample the model using ray-tracing techniques. The code is integrated directly into the BRL-CAD solid model editor and is operated using a simple graphical user interface. Several diagnostic tools are available to allow the user to analyze the results. Based on limited validation using several benchmark problems, results can be expected to fall between a 10% underestimate and a factor of 2 overestimate of the actual dose predicted by rigorous radiation transport techniques. However, other situations may be encountered where the results might fall outside of this range. The code is written in C and uses X-windows graphics. It presently runs on SUN SPARCstations, but in theory could be ported to any workstation with a C compiler and X-windows. SANDOSE is available via license by contacting either the Sandia National Laboratories Technology Transfer Center or the author

Marrow toxicity of fractionated vs. single dose total body irradiation is identical in a canine model

International Nuclear Information System (INIS)

Storb, R.; Raff, R.F.; Graham, T.; Appelbaum, F.R.; Deeg, H.J.; Schuening, F.G.; Shulman, H.; Pepe, M.

1993-01-01

The authors explored in dogs the marrow toxicity of single dose total body irradiation delivered from two opposing 60 Co sources at a rate of 10 cGy/min and compared results to those seen with total body irradiation administered in 100 cGy fractions with minimum interfraction intervals of 6 hr. Dogs were not given marrow transplants. They found that 200 cGy single dose total body irradiation was sublethal, with 12 of 13 dogs showing hematopoietic recovery and survival. Seven of 21 dogs given 300 cGy single dose total body irradiation survived compared to 6 of 10 dogs given 300 cGy fractionated total body irradiation. One of 28 dogs given 400 cGy single dose total body irradiation survived compared to none of six given fractionated radiation. With granulocyte colony stimulating factor (GCSF) administered from day 0-21 after 400 cGy total body irradiation, most dogs survived with hematological recovery. Because of the almost uniform success with GCSF after 400 cGy single dose total body irradiation, a study of GCSF after 400 cGy fractionated total body irradiation was deemed not to be informative and, thus, not carried out. Additional comparisons between single dose and fractionated total body irradiation were carried out with GCSF administered after 500 and 600 cGy of total body irradiation. As with lower doses of total body irradiation, no significant survival differences were seen between the two modes of total body irradiation, and only 3 of 26 dogs studied survived with complete hematological recovery. Overall, therefore, survival among dogs given single dose total body irradiation was not different from that of dogs given fractionated total body irradiation (p = .67). Similarly, the slopes of the postirradiation declines of granulocyte and platelet counts and the rates of their recovery in surviving dogs given equal total doses of single versus fractionated total body irradiation were indistinguishable. 24 refs., 3 figs., 2 tabs

Single-dose radiation therapy for prevention of heterotopic ossification after total hip arthroplasty

International Nuclear Information System (INIS)

Healy, W.L.; Lo, T.C.; Covall, D.J.; Pfeifer, B.A.; Wasilewski, S.A.

1990-01-01

Single-dose radiation therapy was prospectively evaluated for its efficacy in prevention of heterotopic ossification in patients at high risk after total hip arthroplasty. Thirty-one patients (34 hips) were treated between 1981 and 1988. Risk factors for inclusion in the protocol included prior evidence of heterotopic ossification, ankylosing spondylitis, and diffuse idiopathic skeletal hyperostosis. Patients with hypertrophic osteoarthritis or traumatic arthritis with osteophytes were not included. Operations on 34 hips included 19 primary total and 11 revision total hip arthroplasties and 4 excisions of heterotopic ossification. All patients received radiotherapy to the hip after operation with a single dose of 700 centigray. Radiotherapy is recommended on the first postoperative day. After this single-dose radiation treatment, no patient had clinically significant heterotopic ossification. Recurrent disease developed in two hips (6%), as seen on radiography (grades 2 and 3). This series documents a 100% clinical success rate and a 94% radiographic success rate in preventing heterotopic ossification in patients at high risk after total hip arthroplasty. Single-dose radiotherapy is as effective as other radiation protocols in preventing heterotopic ossification after total hip arthroplasty. It is less expensive and easier to administer than multidose radiotherapy

Impact of total ionizing dose on the electromagnetic susceptibility of a single bipolar transistor

International Nuclear Information System (INIS)

Doridant, A.; Jarrix, S.; Raoult, J.; Blain, A.; Dusseau, L.; Chatry, N.; Calvel, P.; Hoffmann, P.

2012-01-01

Space or military electronic components are subject to both electromagnetic fields and total ionizing dose. This paper deals with the electromagnetic susceptibility of a discrete low frequency transistor subject to total ionizing dose deposition. The electromagnetic susceptibility is investigated on both non-irradiated and irradiated transistors mounted in common emitter configuration. The change in susceptibility to 100 MHz-1.5 GHz interferences lights up a synergy effect between near field electromagnetic waves and total ionizing dose. Physical mechanisms leading to changes in signal output are detailed. (authors)

Estimation of the total absorbed dose by quartz in retrospective conditions

International Nuclear Information System (INIS)

Correcher, V.; Delgado, A.

2003-01-01

The estimation of the total absorbed dose is of great interest in areas affected by a radiological accident when no conventional dosimetric systems are available. This paper reports about the usual methodology employed in dose reconstruction from the thermoluminescence (TL) properties of natural quartz, extracted from selected ceramic materials (12 bricks) picked up in the Chernobyl area. It has been possible to evaluate doses under 50mGy after more than 11 years later since the radiological accident happened. The main advance of this fact is the reduction of the commonly accepted limit dose estimation more than 20 times employing luminescence methods. (Author) 11 refs

Theoretical considerations for SRAM total-dose hardening

International Nuclear Information System (INIS)

Francis, P.; Flandre, D.; Colinge, J.P.

1995-01-01

The theoretical hardness against total dose of the six-transistor SRAM cell is investigated in detail. An explicit analytical expression of the maximum tolerable threshold voltage shift is derived for two cross-coupled inverters. A numerical method is used to explore the hardness of the read and write operations. Both N- and P-channel access transistors designs are considered and their respective advantages are compared. The study points out that the radiation hardness mainly relies on the technology. Results obtained with the very robust Gate-All-Around process are finally presented

Feasibility study of helical tomotherapy for total body or total marrow irradiation

International Nuclear Information System (INIS)

Hui, Susanta K.; Kapatoes, Jeff; Fowler, Jack; Henderson, Douglas; Olivera, Gustavo; Manon, Rafael R.; Gerbi, Bruce; Mackie, T. R.; Welsh, James S.

2005-01-01

Total body radiation (TBI) has been used for many years as a preconditioning agent before bone marrow transplantation. Many side effects still plague its use. We investigated the planning and delivery of total body irradiation (TBI) and selective total marrow irradiation (TMI) and a reduced radiation dose to sensitive structures using image-guided helical tomotherapy. To assess the feasibility of using helical tomotherapy (A) we studied variations in pitch, field width, and modulation factor on total body and total marrow helical tomotherapy treatments. We varied these parameters to provide a uniform dose along with a treatment times similar to conventional TBI (15-30 min). (B) We also investigated limited (head, chest, and pelvis) megavoltage CT (MVCT) scanning for the dimensional pretreatment setup verification rather than total body MVCT scanning to shorten the overall treatment time per treatment fraction. (C) We placed thermoluminescent detectors (TLDs) inside a Rando phantom to measure the dose at seven anatomical sites, including the lungs. A simulated TBI treatment showed homogeneous dose coverage (±10%) to the whole body. Doses to the sensitive organs were reduced by 35%-70% of the target dose. TLD measurements on Rando showed an accurate dose delivery (±7%) to the target and critical organs. In the TMI study, the dose was delivered conformally to the bone marrow only. The TBI and TMI treatment delivery time was reduced (by 50%) by increasing the field width from 2.5 to 5.0 cm in the inferior-superior direction. A limited MVCT reduced the target localization time 60% compared to whole body MVCT. MVCT image-guided helical tomotherapy offers a novel method to deliver a precise, homogeneous radiation dose to the whole body target while reducing the dose significantly to all critical organs. A judicious selection of pitch, modulation factor, and field size is required to produce a homogeneous dose distribution along with an acceptable treatment time. In

Analysis of the importance for the doses of varying parameters in the BIOPATH-program

International Nuclear Information System (INIS)

Bergstroem, U.

1981-01-01

The doses to individuals and populations from water-borne nuclides leaked from a repository have been calculated earlier using the computer program BIOPATH. The turnover of nuclides in the biosphere is thereby simulated by the application of compartment theory. For the dominant nuclides in the disposal an analysis of the importance of varying parameters has been done, to decide how strongly uncertainties in data will affect resulting doses. The essential part has been the transfer coefficients but also the uptake in the food-chains has been studied. The purpose of the study has also been to make proposals for forthcoming efforts to improve the basis for such calculations. The study shows the great importance of the surface water-soil-groundwater-drinking water system for the dose. Thereby the most important question is the solubility of the nuclides in the different water reservoirs. (Auth.)

Study of total ionization dose effects in electronic devices

International Nuclear Information System (INIS)

Nidhin, T.S.; Bhattacharyya, Anindya; Gour, Aditya; Behera, R.P.; Jayanthi, T.

2018-01-01

Radiation effects in electronic devices are a major challenge in the dependable application developments of nuclear power plant instrumentation and control systems. The main radiation effects are total ionization dose (TID) effects, displacement damage dose (DDD) effects and single event effects (SEE). In this study, we are concentrating on TID effects in electronic devices. The focus of the study is mainly on SRAM based field programmable gate arrays (FPGA) along with that the devices of our interest are voltage regulators, flash memory and optocoupler. The experiments are conducted by exposing the devices to gamma radiation in power off condition and the degradation in the performances are analysed

Characterization of Radiation Hardened Bipolar Linear Devices for High Total Dose Missions

Science.gov (United States)

McClure, Steven S.; Harris, Richard D.; Rax, Bernard G.; Thorbourn, Dennis O.

2012-01-01

Radiation hardened linear devices are characterized for performance in combined total dose and displacement damage environments for a mission scenario with a high radiation level. Performance at low and high dose rate for both biased and unbiased conditions is compared and the impact to hardness assurance methodology is discussed.

The total dose effects on the 1/f noise of deep submicron CMOS transistors

International Nuclear Information System (INIS)

Hu Rongbin; Wang Yuxin; Lu Wu

2014-01-01

Using 0.18 μm CMOS transistors, the total dose effects on the 1/f noise of deep-submicron CMOS transistors are studied for the first time in mainland China. From the experimental results and the theoretic analysis, we realize that total dose radiation causes a lot of trapped positive charges in STI (shallow trench isolation) SiO 2 layers, which induces a current leakage passage, increasing the 1/f noise power of CMOS transistors. In addition, we design some radiation-hardness structures on the CMOS transistors and the experimental results show that, until the total dose achieves 750 krad, the 1/f noise power of the radiation-hardness CMOS transistors remains unchanged, which proves our conclusion. (semiconductor devices)

Total Ionizing Dose effects in 130-nm commercial CMOS technologies for HEP experiments

CERN Document Server

Gonella, L; Silvestri, M; Gerardin, S; Pantano, D; Re, V; Manghisoni, M; Ratti, L; Ranieri, A

2007-01-01

The impact of foundry-to-foundry variability and bias conditions during irradiation on the Total Ionizing Dose (TID) response of commercial 130-nm CMOS technologies have been investigated for applications in High Energy Physics (HEP) experiments. n- and p-channel MOSFETs from three different manufacturers have been irradiated with X-rays up to more than 100 Mrad (SiO2). Even though the effects of TID are qualitatively similar, the amount of degradation is shown to vary considerably from foundry to foundry, probably depending on the processing of the STI oxide and/or doping profile in the substrate. The bias during irradiation showed to have a strong impact as well on the TID response, proving that exposure at worst case bias conditions largely overestimates the degradation a device may experience during its lifetime. Overall, our results increase the confidence that 130-nm CMOS technologies can be used in future HEP experiments even without Hardness-By-Design solutions, provided that constant monitoring of th...

Serum protein concentration in low-dose total body irradiation of normal and malnourished rats

International Nuclear Information System (INIS)

Viana, W.C.M.; Lambertz, D.; Borges, E.S.; Neto, A.M.O.; Lambertz, K.M.F.T.; Amaral, A.

2016-01-01

Among the radiotherapeutics' modalities, total body irradiation (TBI) is used as treatment for certain hematological, oncological and immunological diseases. The aim of this study was to evaluate the long-term effects of low-dose TBI on plasma concentration of total protein and albumin using prematurely and undernourished rats as animal model. For this, four groups with 9 animals each were formed: Normal nourished (N); Malnourished (M); Irradiated Normal nourished (IN); Irradiated Malnourished (IM). At the age of 28 days, rats of the IN and IM groups underwent total body gamma irradiation with a source of cobalt-60. Total protein and Albumin in the blood serum was quantified by colorimetry. This research indicates that procedures involving low-dose total body irradiation in children have repercussions in the reduction in body-mass as well as in the plasma levels of total protein and albumin. Our findings reinforce the periodic monitoring of total serum protein and albumin levels as an important tool in long-term follow-up of pediatric patients in treatments associated to total body irradiation. - Highlights: • Low-dose total body irradiation (TBI) in children have repercussions in their body-mass. • Long-term total protein and albumin levels are affected by TBI. • The monitoring of total protein and albumin levels are useful in the follow-up of TBI pediatric patients.

Worst-Case Bias During Total Dose Irradiation of SOI Transistors

International Nuclear Information System (INIS)

Ferlet-Cavrois, V.; Colladant, T.; Paillet, P.; Leray, J.-L; Musseau, O.; Schwank, James R.; Shaneyfelt, Marty R.; Pelloie, J.L.; Du Port de Poncharra, J.

2000-01-01

The worst case bias during total dose irradiation of partially depleted SOI transistors (from SNL and from CEA/LETI) is correlated to the device architecture. Experiments and simulations are used to analyze SOI back transistor threshold voltage shift and charge trapping in the buried oxide

Estimation of the dose distribution within, and total dose to, the body of an acutely overexposed person

International Nuclear Information System (INIS)

Beer, G.P. de; Feather, J.I.; Oude, A. de; Language, A.E.

1981-01-01

In a case of accidental overexposure of a person, it is important to obtain a reliable value of the whole body dose as well as of the dose distribution within the body. Any follow-up treatment based only on the clinical effects as and when they appear, may result in insufficient or even erroneous therapy. In this respect knowledge of total dose and its distribution within the body may be a valuable aid in deciding on the follow-up treatment, taking into account the latent nature of the clinical effects. The calculated whole body dose and its distribution within the body of a person overexposed to a 192 Ir radiography source, are compared to experimentally determined values. In both cases the calculated values prove to be of sufficient accuracy to serve as an aid in decisions on the follow-up treatment. (author)

High-dose total-body irradiation and autologous marrow reconstitution in dogs: dose-rate-related acute toxicity and fractionation-dependent long-term survival

International Nuclear Information System (INIS)

Deeg, H.J.; Storb, R.; Weiden, P.L.; Schumacher, D.; Shulman, H.; Graham, T.; Thomas, E.D.

1981-01-01

Beagle dogs treated by total-body irradiation (TBI) were given autologous marrow grafts in order to avoid death from marrow toxicity. Acute and delayed non-marrow toxicities of high single-dose (27 dogs) and fractionated TBI (20 dogs) delivered at 0.05 or 0.1 Gy/min were compared. Fractionated TBI was given in increments of 2 Gy every 6 hr for three increments per day. Acute toxicity and early mortality (<1 month) at identical total irradiation doses were comparable for dogs given fractionated or single-dose TBI. With single-dose TBI, 14, 16, and 18 Gy, respectively, given at 0.05 Gy/min, 0/5, 5/5, and 2/2 dogs died from acute toxicity; with 10, 12, and 14 Gy, respectively, given at 0.1 Gy/min, 1/5, 4/5, and 5/5 dogs died acutely. With fractionated TBI, 14 and 16 Gy, respectively, given at 0.1 Gy/min, 1/5, 4/5, and 2/2 dogs died auctely. Early deaths were due to radiation enteritis with or without associated septicemia (29 dogs; less than or equal to Day 10). Three dogs given 10 Gy of TBI at 0.1 Gy/min died from bacterial pneumonia; one (Day 18) had been given fractionated and two (Days 14, 22) single-dose TBI. Fifteen dogs survived beyond 1 month; eight of these had single-dose TBI (10-14 Gy) and all died within 7 months of irradiation from a syndrome consisting of hepatic damage, pancreatic fibrosis, malnutrition, wasting, and anemia. Seven of the 15 had fractionated TBI, and only one (14 Gy) died on Day 33 from hepatic failure, whereas 6 (10-14 Gy) are alive and well 250 to 500 days after irradiation. In conclusion, fractionated TBI did not offer advantages over single-dose TBI with regard to acute toxicity and early mortality; rather, these were dependent upon the total dose of TBI. The total acutely tolerated dose was dependent upon the exposure rate; however, only dogs given fractionated TBI became healthy long-term survivors

Impact of radiation technique, radiation fraction dose, and total cisplatin dose on hearing. Retrospective analysis of 29 medulloblastoma patients

International Nuclear Information System (INIS)

Scobioala, Sergiu; Kittel, Christopher; Ebrahimi, Fatemeh; Wolters, Heidi; Eich, Hans Theodor; Parfitt, Ross; Matulat, Peter; Am Zehnhoff-Dinnesen, Antoinette

2017-01-01

To analyze the incidence and degree of sensorineural hearing loss (SNHL) resulting from different radiation techniques, fractionation dose, mean cochlear radiation dose (D mean ), and total cisplatin dose. In all, 29 children with medulloblastoma (58 ears) with subclinical pretreatment hearing thresholds participated. Radiotherapy (RT) and cisplatin had been applied sequentially according to the HIT MED Guidance. Audiological outcomes up to the latest follow-up (median 2.6 years) were compared. Bilateral high-frequency SNHL was observed in 26 patients (90%). No significant differences were found in mean hearing threshold between left and right ears at any frequency. A significantly better audiological outcome (p < 0.05) was found after tomotherapy at the 6 kHz bone-conduction threshold (BCT) and left-sided 8 kHz air-conduction threshold (ACT) than after a combined radiotherapy technique (CT). Fraction dose was not found to have any impact on the incidence, degree, and time-to-onset of SNHL. Patients treated with CT had a greater risk of SNHL at high frequencies than tomotherapy patients even though D mean was similar. Increase in severity of SNHL was seen when the total cisplatin dose reached above 210 mg/m 2 , with the highest abnormal level found 8-12 months after RT regardless of radiation technique or fraction dose. The cochlear radiation dose should be kept as low as possible in patients who receive simultaneous cisplatin-based chemotherapy. The risk of clinically relevant HL was shown when D mean exceeds 45 Gy independent of radiation technique or radiation regime. Cisplatin ototoxicity was shown to have a dose-dependent effect on bilateral SNHL, which was more pronounced in higher frequencies. (orig.) [de

Pharmacokinetics and Safety of a Single Oral Dose of Mirogabalin in Japanese Subjects With Varying Degrees of Renal Impairment.

Science.gov (United States)

Kato, Manabu; Tajima, Naoyuki; Shimizu, Takako; Sugihara, Masahiro; Furihata, Kenichi; Harada, Kazuhiro; Ishizuka, Hitoshi

2018-01-01

Mirogabalin (DS-5565) is a novel preferentially selective α 2 δ-1 ligand being developed for the treatment of diabetic peripheral neuropathic pain and postherpetic neuralgia. The current multicenter open-label study determined the effect of varying degrees of renal impairment on the pharmacokinetics and safety of a single dose of mirogabalin 5 mg in Japanese subjects. A total of 30 subjects (6 subjects per renal function category [normal, mild, moderate, or severe impairment; and end-stage renal disease (ESRD)]) were enrolled and completed the study. The AUC last increased with severity of renal impairment; the geometric least-squares mean ratios of AUC last compared with subjects with normal renal function were 1.3, 1.9, 3.6, and 5.3 for patients with mild, moderate, and severe impairment and ESRD, respectively. In accordance with this AUC last increase, apparent total body clearance (CL/F), renal clearance (CLr), and the cumulative percentage of mirogabalin dose excreted into urine all decreased with severity of renal impairment. There were no deaths and no severe treatment-related adverse events (TEAEs), serious TEAEs, or TEAEs resulting in study discontinuation. Mirogabalin was well tolerated in Japanese subjects with normal renal function and those with mild to severe renal impairment. It was also tolerated in subjects with ESRD but with a higher incidence of TEAEs. The most frequently reported TEAEs were dizziness (ESRD, n = 3), somnolence (ESRD, n = 2), and vomiting (ESRD, n = 2). Based on these data, a mirogabalin dose adjustment will be considered in Japanese subjects with moderate to severe renal impairment and those with ESRD. © 2017, The Authors. The Journal of Clinical Pharmacology published by Wiley Periodicals, Inc. on behalf of American College of Clinical Pharmacology.

Dose rate and total dose dependence of the 1/f noise performance of a GaAs operational amplifier during irradiation

International Nuclear Information System (INIS)

Hiemstra, D.M.

1995-01-01

A pictorial of a sectioned view of the torus of the International Thermonuclear Experimental Reactor (ITER) is shown. Maintenance and inspection of the reactor are required to be performed remotely. This is due to the high gamma radiation environment in vessel during inspection and maintenance activities. The custom GaAs operational amplifier is to be used to readout sensors on the in-vessel manipulator and inspection equipment. The gamma dose rate during maintenance and inspection is anticipated to be 3 Mrad(GaAs)/hour. Here, dose rate and total dose dependence of the 1/f noise performance of a custom GaAs MESFET operational amplifier during irradiation are presented. Dose rate dependent 1/f noise degradation during irradiation is believed to be due to electron trapping in deep levels, enhanced by backgating and shallow traps excited during irradiation. The reduction of this affect with accumulated total dose is believed to be due a reduction of deep level site concentration associated with substitutional oxygen. Post irradiation 1/f noise degradation is also presented.The generation-recombination noise observed post irradiation can be attributed to the production of shallow traps due to ionizing radiation

Muscle-invasive bladder cancer treated with external beam radiation: influence of total dose, overall treatment time, and treatment interruption on local control

International Nuclear Information System (INIS)

Moonen, L.; Voet, H. van der; Nijs, R. de; Horenblas, S.; Hart, A.A.M.; Bartelink, H.

1998-01-01

Purpose: To evaluate and eventually quantify a possible influence of tumor proliferation during the external radiation course on local control in muscle invasive bladder cancer. Methods and Materials: The influence of total dose, overall treatment time, and treatment interruption has retrospectively been analyzed in a series of 379 patients with nonmetastasized, muscle-invasive transitional cell carcinoma of the urinary bladder. All patients received external beam radiotherapy at the Netherlands Cancer Institute between 1977 and 1990. Total dose varied between 50 and 75 Gy with a mean of 60.5 Gy and a median of 60.4 Gy. Overall treatment time varied between 20 and 270 days with a mean of 49 days and a median of 41 days. Number of fractions varied between 17 and 36 with a mean of 27 and a median of 26. Two hundred and forty-four patients had a continuous radiation course, whereas 135 had an intended split course or an unintended treatment interruption. Median follow-up was 22 months for all patients and 82 months for the 30 patients still alive at last follow-up. A stepwise procedure using proportional hazard regression has been used to identify prognostic treatment factors with respect to local recurrence as sole first recurrence. Results: One hundred and thirty-six patients experienced a local recurrence and 120 of these occurred before regional or distant metastases. The actuarial local control rate was 40.3% at 5 years and 32.3% at 10 years. In a multivariate analysis total dose showed a significant association with local control (p 0.0039), however in a markedly nonlinear way. In fact only those patients treated with a dose below 57.5 Gy had a significant higher bladder relapse rate, whereas no difference in relapse rate was found among patients treated with doses above 57.5 Gy. This remained the case even after adjustment for overall treatment time and all significant tumor and patient characteristics. The Normalized Tumor Dose (NTD) (α/β = 10) and NTD (�

Total skin high-dose-rate electron therapy dosimetry using TG-51

International Nuclear Information System (INIS)

Gossman, Michael S.; Sharma, Subhash C.

2004-01-01

An approach to dosimetry for total skin electron therapy (TSET) is discussed using the currently accepted TG-51 high-energy calibration protocol. The methodology incorporates water phantom data for absolute calibration and plastic phantom data for efficient reference dosimetry. The scheme is simplified to include the high-dose-rate mode conversion and provides support for its use, as it becomes more available on newer linear accelerators. Using a 6-field, modified Stanford technique, one may follow the process for accurate determination of absorbed dose

Optimization of total arc degree for stereotactic radiotherapy by using integral biologically effective dose and irradiated volume

International Nuclear Information System (INIS)

Lim, Do Hoon; Kim, Dae Yong; Lee, Myung Za; Chun, Ha Chung

2001-01-01

To find the optimal values of total arc degree to protect the normal brain tissue from high dose radiation in stereotactic radiotherapy planning. With Xknife-3 planning system and 4 MV linear accelerator, the authors planned under various values of parameters. One isocenter, 12, 20, 30, 40, 50, and 60 mm of collimator diameters, 100 deg, 200 deg, 300 deg, 400 deg, 500 deg, 600 deg, of total arc degrees, and 30 deg or 45 deg of arc intervals were used. After the completion of planning, the plans were compared each other using V 50 (the volume of normal brain that is delivered high dose radiation) and integral biologically effective dose. At 30 deg of arc interval, the values of V 50 had the decreased pattern with the increase of total arc degree in any collimator diameter. At 45 deg arc interval, up to 400 deg of total arc degree, the values of V 50 decreased with the increase of total arc degree, but at 500 deg and 600 deg of total arc degrees, the values increased. At 30 deg of arc interval, integral biologically effective dose showed the decreased pattern with the increase of total arc degree in any collimator diameter. At 45 deg arc interval with less than 40 mm collimator diameter, the integral biologically effective dose decreased with the increase of total arc degree, but with 50 and 60 mm of collimator diameters, up to 400 deg of total arc degree, integral biologically effective dose decreased with the increase of total arc degree, but at 500 deg and 600 deg of total arc degrees, the values increased. In the stereotactic radiotherapy planning for brain lesions, planning with 400 deg of total arc degree is optimal. Especially, when the larger collimator more than 50 mm diameter should be used, the uses of 500 deg and 600 deg of total arc degrees make the increase of V 50 and integral biologically effective dose, Therefore stereotactic radiotherapy planning using 400 deg of total arc degree can increase the therapeutic ratio and produce the effective outcome

Safety aspects of preoperative high-dose glucocorticoid in primary total knee replacement

DEFF Research Database (Denmark)

Jørgensen, C C; Pitter, F T; Kehlet, H

2017-01-01

Background: Preoperative single high-dose glucocorticoid may have early outcome benefits in total hip arthroplasty (THA) and knee arthroplasty (TKA), but long-term safety aspects have not been evaluated. Methods: From October 2013, the departments reporting to the prospective Lundbeck Foundation....... Conclusions: In this detailed prospective cohort study, preoperative high-dose glucocorticoid administration was not associated with LOS >4 days, readmissions or infectious complications in TKA patients without contraindications....

Enhancement of Transistor-to-Transistor Variability Due to Total Dose Effects in 65-nm MOSFETs

CERN Document Server

Gerardin, S; Cornale, D; Ding, L; Mattiazzo, S; Paccagnella, A; Faccio, F; Michelis, S

2015-01-01

We studied device-to-device variations as a function of total dose in MOSFETs, using specially designed test structures and procedures aimed at maximizing matching between transistors. Degradation in nMOSFETs is less severe than in pMOSFETs and does not show any clear increase in sample-to-sample variability due to the exposure. At doses smaller than 1 Mrad( SiO2) variability in pMOSFETs is also practically unaffected, whereas at very high doses-in excess of tens of Mrad( SiO2)-variability in the on-current is enhanced in a way not correlated to pre-rad variability. The phenomenon is likely due to the impact of random dopant fluctuations on total ionizing dose effects.

A prospective, open-label study of low-dose total skin electron beam therapy in mycosis fungoides

DEFF Research Database (Denmark)

Kamstrup, Maria R; Specht, Lena; Skovgaard, Gunhild L

2008-01-01

causes and did not complete treatment. Acute side effects included desquamation, xerosis, and erythema of the skin. No severe side effects were observed. CONCLUSION: Low-dose total skin electron beam therapy can induce complete and partial responses in Stage IB-II mycosis fungoides; however, the duration......PURPOSE: To determine the effect of low-dose (4 Gy) total skin electron beam therapy as a second-line treatment of Stage IB-II mycosis fungoides in a prospective, open-label study. METHODS AND MATERIALS: Ten patients (6 men, 4 women, average age 68.7 years [range, 55-82 years......]) with histopathologically confirmed mycosis fungoides T2-T4 N0-N1 M0 who did not achieve complete remission or relapsed within 4 months after treatment with psoralen plus ultraviolet-A were included. Treatment consisted of low-dose total skin electron beam therapy administered at a total skin dose of 4 Gy given in 4...

The effects of dose rate in total body irradiation of dogs

International Nuclear Information System (INIS)

Kolb, H.J.; Bodenberger, U.; Holler, E.; Thierfelder, S.; Eckstein, R.

1986-01-01

In summary the studies in dogs show that the dose rate or exposure time has a great impact on survival of acute radiation syndromes. In contrast the inactivation of colony forming hemopoietic precursors is less influenced by the dose rate. The potential of hemopoietic recovery is determined by the survival of hemopoietic precursor cells. Therefore in patients with a suspected whole body exposure of more than 1.50 Gy, bacterial and fungal decontamination and reverse isolation in a sterile environment has to be started immediately. Human patients treated with about 10 Gy of TBI frequently developed nausea, elevated temperatures and swelling of the parotic glands at the first and second day. The extent of these changes varies from patient to patient. The temperature is rarely elevated above 38.5 0 C. The swelling of parotics and the nausea subside within 48 hours. The presence of such systemic symptoms may suggest the exposure to a lethal dose of radiation. The disappearance of immature red cells, i.e. reticulocytes, and bandforms of granulocytes within the first 5 days supports this suggestion. HLA typing of the victim and his family should be performed as soon as possible after the accident. An HLA-identical sibling would be a suitable bone marrow donor. Unlike therapeutic TBI accidental exposures bring about uncertainties in the calculation of dose, dose distribution and dose rate. Early after irradiation biological changes are extremely variable. Both biological and physical data have to be considered, when microbiological decontamination, reverse isolation and transplantation of bone marrow are to be decided upon. Obviously these intensive therapeutic efforts are limited to a small number of victims. (orig.)

Laboratory Bioaccumulation, Depuration And Total Dose Rate Of Waterborne Th-232 In Freshwater Fish Of Anabas Testudineus

International Nuclear Information System (INIS)

Zal U'yun Wan Mahmood; Norfaizal Mohamed; Nita Salina Abu Bakar

2014-01-01

Preliminary results on the study of bioaccumulation, depuration and total dose rate of Th-232 in the whole body of Anabas testudineus are presented. The objective of this study was to evaluate the effect of Th-232 concentration activity on the laboratory bioaccumulation, depuration and total dose rate in Anabas testudineus. Anabas testudineus adults were exposed to different waterborne Th-232 levels: 0 BqL -1 (control), 50 BqL -1 and 100 BqL -1 for 30 day (uptake phase), followed by exposure to radionuclide-free water for 30 days (loss phase). Radionuclide concentration ratios between the whole body levels and water levels, percentage of Th-232 remaining in fish were calculated and total dose rates using ERICA Assessment Tool were also estimated. The results showed the increase of waterborne Th-232 concentration corresponded to a progressive increase of Th accumulation and total dose rate (internal and external) in the whole body of Anabas testudineus. Considering the ERICA dose rate screening value of 10 μGyh -1 , the findings can be concluded the estimated of total dose rate (< 5 μGyh -1 ) in Anabas testudineus is in order of small magnitude. Nevertheless, these preliminary results showed that the Anabas testudineus has a potential to accumulate thorium. (author)

Total dose induced latch in short channel NMOS/SOI transistors

International Nuclear Information System (INIS)

Ferlet-Cavrois, V.; Quoizola, S.; Musseau, O.; Flament, O.; Leray, J.L.; Pelloie, J.L.; Raynaud, C.; Faynot, O.

1998-01-01

A latch effect induced by total dose irradiation is observed in short channel SOI transistors. This effect appears on NMOS transistors with either a fully or a partially depleted structure. It is characterized by a hysteresis behavior of the Id-Vg characteristics at high drain bias for a given critical dose. Above this dose, the authors still observe a limited leakage current at low drain bias (0.1 V), but a high conduction current at high drain bias (2 V) as the transistor should be in the off-state. The critical dose above which the latch appears strongly depends on gate length, transistor structure (fully or partially depleted), buried oxide thickness and supply voltage. Two-dimensional (2D) numerical simulations indicate that the parasitic condition is due to the latch of the back gate transistor triggered by charge trapping in the buried oxide. To avoid the latch induced by the floating body effect, different techniques can be used: doping engineering, body contacts, etc. The study of the main parameters influencing the latch (gate length, supply voltage) shows that the scaling of technologies does not necessarily imply an increased latch sensitivity. Some technological parameters like the buried oxide hardness and thickness can be used to avoid latch, even at high cumulated dose, on highly integrated SOI technologies

Occupational radiation dose in Indonesia 1981-1986

International Nuclear Information System (INIS)

Hiswara, E.; Ismono, A.

1993-01-01

Occupational radiation dose in Indonesia 1981-1986. This paper presents the occupational radiation dose in Indonesia during the period of 1981-1986. The highest collective dose accurated in 1983 was calculated to be 2.68 man-Sv, with the maximum mean dose per worker, who received dose more than zero, was around 11.07 mSv in the same year. In 1985, a relative collective dose from medical occupations of 1.88 man mSv for 10 6 population was estimated based on its total collective dose of 0.31 man-mSv. The total number of workers who received annual collective dose less than 5 mSv varied from 97.0% in 1981 to 99.5% in 1986. As a group, the industrial occupations has considerably higher risk in receiving a dose than others. (authors). 11 refs., 7 tabs

Low-dose total skin electron beam therapy for cutaneous lymphoma : Minimal risk of acute toxicities.

Science.gov (United States)

Kroeger, Kai; Elsayad, Khaled; Moustakis, Christos; Haverkamp, Uwe; Eich, Hans Theodor

2017-12-01

Low-dose total skin electron beam therapy (TSEBT) is attracting increased interest for the effective palliative treatment of primary cutaneous T‑cell lymphoma (pCTCL). In this study, we compared toxicity profiles following various radiation doses. We reviewed the records of 60 patients who underwent TSEBT for pCTCL between 2000 and 2016 at the University Hospital of Munster. The treatment characteristics of the radiotherapy (RT) regimens and adverse events (AEs) were then analyzed and compared. In total, 67 courses of TSEBT were administered to 60 patients. Of these patients, 34 (51%) received a standard dose with a median surface dose of 30 Gy and 33 patients (49%) received a low dose with the median surface dose of 12 Gy (7 salvage low-dose TSEBT courses were administered to 5 patients). After a median follow-up of 15 months, the overall AE rate was 100%, including 38 patients (57%) with grade 2 and 7 (10%) with grade 3 AEs. Patients treated with low-dose TSEBT had significantly fewer grade 2 AEs than those with conventional dose regimens (33 vs. 79%, P dose regimen compared to those with the conventional dose regimens (6 vs. 15%, P = 0.78). Multiple/salvage low-dose TSEBT courses were not associated with an increased risk of acute AEs. Low-dose TSEBT regimens are associated with significantly fewer grade 2 acute toxicities compared with conventional doses of TSEBT. Repeated/Salvage low-dose TSEBT, however, appears to be tolerable and can even be applied safely in patients with cutaneous relapses.

Clinical study on the adriamycin induced cardiomyopathy using the cardiac magnetic resonance imaging. Total dose and cardiac dysfunction

International Nuclear Information System (INIS)

Yamaguchi, Kyoko; Teraoka, Kunihiko; Hirano, Masaharu

2001-01-01

We studied cardiac functional disorders caused by Adoriamycin using gadolinium (Gd) contrast cine MRI. Forty-eight patients were given ACT (31 men and 17 women; mean age, 52±15 years). First, the relationship between dose and the left ventricular volume, cardiac function, left ventricular cardiac mass and localized wall motion were examined in all patients. Patients given a total dose of 300 mg/m 2 or higher were assigned to the high dose group and those given doses under 300 mg/m 2 to the low dose group. The same parameters were studied in both groups and compared. A 1.5-Tesla superconductive MRI was used for all studies. Cine images of the long and short axes at the papillary muscle level were obtained by ECG R-wave synchronized Gd contrast cine MRI. Left ventricular volume and cardiac function were analyzed using the long-axis cine images and the wall thickness in diastole and systole was measured at each site using the short-axis cine images. The percentage of wall thickness was calculated at each site. The mean ACT dose was 273.3±218.2 mg/m 2 . In all patients the total dose directly correlated with ESVI and inversely correlated with the ejection fraction (EF). In the high dose group, the total dose and EF were inversely correlated, but no significant differences were observed in the low dose group. In the high dose group, the ESVI was significantly greater and the SVI and EF were more significantly reduced than in the low dose group. In the high dose group, the thickness of the anterior, lateral and posterior walls, excluding the septum, was significantly lower than in the low dose group. However, changes in wall thickness were not significantly different between the groups. Gd contrast cine MRI was useful in examining cardiac functional disorders caused by anthracyclines. The total dose of anthracycline correlated directly with the ESVI, and inversely with the EF. A total dose of 300 mg/m 2 appeared to be the borderline dose beyond which there were

Clinical study on the adriamycin induced cardiomyopathy using the cardiac magnetic resonance imaging. Total dose and cardiac dysfunction

Energy Technology Data Exchange (ETDEWEB)

Yamaguchi, Kyoko; Teraoka, Kunihiko; Hirano, Masaharu [Tokyo Medical Coll. (Japan)

2001-05-01

We studied cardiac functional disorders caused by Adoriamycin using gadolinium (Gd) contrast cine MRI. Forty-eight patients were given ACT (31 men and 17 women; mean age, 52{+-}15 years). First, the relationship between dose and the left ventricular volume, cardiac function, left ventricular cardiac mass and localized wall motion were examined in all patients. Patients given a total dose of 300 mg/m{sup 2} or higher were assigned to the high dose group and those given doses under 300 mg/m{sup 2} to the low dose group. The same parameters were studied in both groups and compared. A 1.5-Tesla superconductive MRI was used for all studies. Cine images of the long and short axes at the papillary muscle level were obtained by ECG R-wave synchronized Gd contrast cine MRI. Left ventricular volume and cardiac function were analyzed using the long-axis cine images and the wall thickness in diastole and systole was measured at each site using the short-axis cine images. The percentage of wall thickness was calculated at each site. The mean ACT dose was 273.3{+-}218.2 mg/m{sup 2}. In all patients the total dose directly correlated with ESVI and inversely correlated with the ejection fraction (EF). In the high dose group, the total dose and EF were inversely correlated, but no significant differences were observed in the low dose group. In the high dose group, the ESVI was significantly greater and the SVI and EF were more significantly reduced than in the low dose group. In the high dose group, the thickness of the anterior, lateral and posterior walls, excluding the septum, was significantly lower than in the low dose group. However, changes in wall thickness were not significantly different between the groups. Gd contrast cine MRI was useful in examining cardiac functional disorders caused by anthracyclines. The total dose of anthracycline correlated directly with the ESVI, and inversely with the EF. A total dose of 300 mg/m{sup 2} appeared to be the borderline dose beyond

Nitrate-induced changes and effect of varying total nitrogen to total ...

African Journals Online (AJOL)

Microcystis aeruginosa, a common cyanobacterium in Lake Chivero, did not assume dominance in any of the treatments. From an application perspective it is interesting that varying nitrate loadings in microcosms favoured chlorophytes rather than increasing undesirable cyanobacteria. Nutrient manipulation can be used as ...

The Role of Electron Transport and Trapping in MOS Total-Dose Modeling

International Nuclear Information System (INIS)

Flament, O.; Fleetwood, D.M.; Leray, J.L.; Paillet, P.; Riewe, L.C.; Winokur, P.S.

1999-01-01

Deep and shallow electron traps form in irradiated thermal SiO 2 as a natural response to hole transport and trapping. The density and stability of these defects are discussed, as are their implications for total-dose modeling

SU-E-T-515: Field-In-Field Compensation Technique Using Multi-Leaf Collimator to Deliver Total Body Irradiation (TBI) Dose

Energy Technology Data Exchange (ETDEWEB)

Lakeman, T [The State University of New York at Buffalo (United States); Wang, IZ [The State University of New York at Buffalo (United States); Roswell Park Cancer Institute, Buffalo, NY (United States)

2014-06-01

Purpose: Total body irradiation (TBI) uses large parallel-opposed radiation fields to suppress the patient's immune system and eradicate the residual cancer cells in preparation of recipient for bone marrow transplant. The manual placement of lead compensators has been used conventionally to compensate for the varying thickness through the entire body in large-field TBI. The goal of this study is to pursue utilizing the modern field-in-field (FIF) technique with the multi-leaf collimator (MLC) to more accurately and efficiently deliver dose to patients in need of TBI. Method: Treatment plans utilizing the FIF technique to deliver a total body dose were created retrospectively for patients for whom CT data had been previously acquired. Treatment fields include one pair of opposed open large fields (collimator=45°) with a specific weighting and a succession of smaller fields (collimator=90°) each with their own weighting. The smaller fields are shaped by moving MLC to block the sections of the patient which have already received close to 100% of the prescribed dose. The weighting factors for each of these fields were calculated using the attenuation coefficient of the initial lead compensators and the separation of the patient in different positions in the axial plane. Results: Dose-volume histograms (DVH) were calculated for evaluating the FIF compensation technique. The maximum body doses calculated from the DVH were reduced from the non-compensated 179.3% to 148.2% in the FIF plans, indicating a more uniform dose with the FIF compensation. All calculated monitor units were well within clinically acceptable limits and exceeded those of the original lead compensation plan by less than 50 MU (only ~1.1% increase). Conclusion: MLC FIF technique for TBI will not significantly increase the beam on time while it can substantially reduce the compensator setup time and the potential risk of errors in manually placing lead compensators.

The Role of Electron Transport and Trapping in MOS Total-Dose Modeling

International Nuclear Information System (INIS)

Fleetwood, D.M.; Winokur, P.S.; Riewe, L.C.; Flament, O.; Paillet, P.; Leray, J.L.

1999-01-01

Radiation-induced hole and electron transport and trapping are fundamental to MOS total-dose models. Here we separate the effects of electron-hole annihilation and electron trapping on the neutralization of radiation-induced charge during switched-bias irradiation for hard and soft oxides, via combined thermally stimulated current (TSC) and capacitance-voltage measurements. We also show that present total-dose models cannot account for the thermal stability of deeply trapped electrons near the Si/SiO 2 interface, or the inability of electrons in deep or shallow traps to contribute to TSC at positive bias following (1) room-temperature, (2) high-temperature, or (3) switched-bias irradiation. These results require revisions of modeling parameters and boundary conditions for hole and electron transport in SiO 2 . The nature of deep and shallow electron traps in the near-interfacial SiO 2 is discussed

A first-principles approach to total-dose hardness assurance

International Nuclear Information System (INIS)

Fleetwood, D.M.

1995-01-01

A first-principles approach to radiation hardness assurance was described that provides the technical background to the present US and European total-dose radiation hardness assurance test methods for MOS technologies, TM 1019.4 and BS 22900. These test methods could not have been developed otherwise, as their existence depends not on a wealth of empirical comparisons of IC data from ground and space testing, but on a fundamental understanding of MOS defect growth and annealing processes. Rebound testing should become less of a problem for advanced MOS small-signal electronics technologies for systems with total dose requirements below 50--100 krad(SiO 2 ) because of trends toward much thinner gate oxides. For older technologies with thicker gate oxides and for power devices, rebound testing is unavoidable without detailed characterization studies to assess the impact of interface traps on devices response in space. The QML approach is promising for future hardened technologies. A sufficient understanding of process effects on radiation hardness has been developed that should be able to reduce testing costs in the future for hardened parts. Finally, it is hoped that the above discussions have demonstrated that the foundation for cost-effective hardness assurance tests is laid with studies of the basic mechanisms of radiation effects. Without a diligent assessment of new radiation effects mechanisms in future technologies, one cannot be assured that the present generation of radiation test standards will continue to apply

Total dose hardness of a commercial SiGe BiCMOS technology

International Nuclear Information System (INIS)

Van Vonno, N.; Lucas, R.; Thornberry, D.

1999-01-01

Over the past decade SiGe HBT technology has progress from the laboratory to actual commercial applications. When integrated into a BiMOS process, this technology has applications in low-cost space systems. In this paper, we report results of total dose testing of a SiGe/CMOS process accessible through a commercial foundry. (authors)

Simulation of Shielding Effects on the Total Dose Observed in TDE of KISAT-1

Directory of Open Access Journals (Sweden)

Sung-Joon Kim

2001-06-01

Full Text Available The threshold voltage shift observed in TDE (Total Dose Experiment on board the KITSAT-1 is converted into dose (rad(SiO2 usinsg the result of laboratory calibration with Co-60 gamma ray source in KAERI (Korea Atomic Energy Research Institute. Simulation using the NASA radiation model of geomagnetosphere verifies that the dose difference between RADFET1 and RADFET3 observed on KITSAT-1 comes from the difference in shielding thickness at the position of these RADFETs.

Inclusion of Radiation Environment Variability in Total Dose Hardness Assurance Methodology

Science.gov (United States)

Xapsos, M. A.; Stauffer, C.; Phan, A.; McClure, S. S.; Ladbury, R. L.; Pellish, J. A.; Campola, M. J.; LaBel, K. A.

2016-01-01

Variability of the space radiation environment is investigated with regard to parts categorization for total dose hardness assurance methods. It is shown that it can have a significant impact. A modified approach is developed that uses current environment models more consistently and replaces the radiation design margin concept with one of failure probability during a mission.

Emesis as a Screening Diagnostic for Low Dose Rate (LDR) Total Body Radiation Exposure.

Science.gov (United States)

Camarata, Andrew S; Switchenko, Jeffrey M; Demidenko, Eugene; Flood, Ann B; Swartz, Harold M; Ali, Arif N

2016-04-01

Current radiation disaster manuals list the time-to-emesis (TE) as the key triage indicator of radiation dose. The data used to support TE recommendations were derived primarily from nearly instantaneous, high dose-rate exposures as part of variable condition accident databases. To date, there has not been a systematic differentiation between triage dose estimates associated with high and low dose rate (LDR) exposures, even though it is likely that after a nuclear detonation or radiologic disaster, many surviving casualties would have received a significant portion of their total exposure from fallout (LDR exposure) rather than from the initial nuclear detonation or criticality event (high dose rate exposure). This commentary discusses the issues surrounding the use of emesis as a screening diagnostic for radiation dose after LDR exposure. As part of this discussion, previously published clinical data on emesis after LDR total body irradiation (TBI) is statistically re-analyzed as an illustration of the complexity of the issue and confounding factors. This previously published data includes 107 patients who underwent TBI up to 10.5 Gy in a single fraction delivered over several hours at 0.02 to 0.04 Gy min. Estimates based on these data for the sensitivity of emesis as a screening diagnostic for the low dose rate radiation exposure range from 57.1% to 76.6%, and the estimates for specificity range from 87.5% to 99.4%. Though the original data contain multiple confounding factors, the evidence regarding sensitivity suggests that emesis appears to be quite poor as a medical screening diagnostic for LDR exposures.

Analysis of Surface Dose Refer to Distance between Beam Spoiler and Patient in Total Body Irradiation

International Nuclear Information System (INIS)

Choi, Jong Hwan; Kim, Jong Sik; Choi, Ji Min; Shin, Eun Hyuk; Song, Ki Won; Park, Young Hwan

2007-01-01

Total body irradiation is used to kill the total malignant cell and for immunosuppression component of preparatory regimens for bone-marrow restitution of patients. Beam spoiler is used to increase the dose to the superficial tissues. This paper finds the property of the distance between beam spoiler and patient. Set-up conditions are 6 MV-Xray, 300 MU, SAD = 400 cm, field size = 40 x 40 cm 2 . The parallel plate chamber located in surface, midpoint and exit of solid water phantom. The surface dose is measured while the distance between beam spoiler and patient is altered. Because it should be found proper distance. The solid water phantom is fixer and beam spoiler is moving. Central dose of phantom is 10.7 cGy and exit dose is 6.7 cGy. In case of distance of 50 cm to 60 cm between beam spoiler and solid water phantom, incidence dose is 14.58-14.92 cGy. Therefore, The surface dose was measured 99.4-101% with got near most to the prescription dose. In clinical case, distance between beam spoiler and patient affect surface dose. If once 50-60 cm of distance between beam spoiler and patient, surface dose of patient got near prescription dose. It would be taken distance between beam spoiler and patient into account in clinical therapy.

Influence of burn-in on total-ionizing-dose effect of SRAM device

International Nuclear Information System (INIS)

Liu Minbo; Yao Zhibin; Huang Shaoyan; He Baoping; Sheng Jiangkun

2014-01-01

The influence of Burn-in on the total-ionizing-dose (TID) effect of SRAM device was investigated. SRAM devices of three different feature sizes were selected and irradiated by "6"0Co source with or without pre-irradiation Burn-in. Some parameters for radiation effect of SRAM device such as upset data, were measured, and the influence on the TID effect of different feature size SRAM devices with or without pre-irradiation Burn-in was obtained. The influence of different temperature Burn-in on radiation resistant capability of SRAM device was studied for 0.25 μm SRAM device. The results show that the smaller the device feature size is, the better the radiation-resistant capability of SRAM device is and the weaker the influence of Burn-in is. And the higher Burn-in temperature is, the more serious the influence of Burn-in on the total-dose radiation effect is. (authors)

Total dose hardening of buried insulator in implanted silicon-on-insulator structures

International Nuclear Information System (INIS)

Mao, B.Y.; Chen, C.E.; Pollack, G.; Hughes, H.L.; Davis, G.E.

1987-01-01

Total dose characteristics of the buried insulator in implanted silicon-on-insulator (SOI) substrates have been studied using MOS transistors. The threshold voltage shift of the parasitic back channel transistor, which is controlled by charge trapping in the buried insulator, is reduced by lowering the oxygen dose as well as by an additional nitrogen implant, without degrading the front channel transistor characteristics. The improvements in the radiation characteristics of the buried insulator are attributed to the decrease in the buried oxide thickness or to the presence of the interfacial oxynitride layer formed by the oxygen and nitrogen implants

Enchanced total dose damage in junction field effect transistors and related linear integrated circuits

International Nuclear Information System (INIS)

Flament, O.; Autran, J.L.; Roche, P.; Leray, J.L.; Musseau, O.

1996-01-01

Enhanced total dose damage of Junction Field-effect Transistors (JFETs) due to low dose rate and/or elevated temperature has been investigated for elementary p-channel structures fabricated on bulk and SOI substrates as well as for related linear integrated circuits. All these devices were fabricated with conventional junction isolation (field oxide). Large increases in damage have been revealed by performing high temperature and/or low dose rate irradiations. These results are consistent with previous studies concerning bipolar field oxides under low-field conditions. They suggest that the transport of radiation-induced holes through the oxide is the underlying mechanism. Such an enhanced degradation must be taken into account for low dose rate effects on linear integrated circuits

An improved standard total dose test for CMOS space electronics

International Nuclear Information System (INIS)

Fleetwood, D.M.; Winokur, P.S.; Riewe, L.C.; Pease, R.L.

1989-01-01

The postirradiation response of hardened and commercial CMOS devices is investigated as a function of total dose, dose rate, and annealing time and temperature. Cobalt-60 irradiation at ≅ 200 rad(SiO 2 )/s followed by a 1-week 100 degrees C biased anneal and testing is shown to be an effective screen of hardened devices for space use. However, a similar screen and single-point test performed after Co-60 irradiation and elevated temperature anneal cannot be generally defined for commercial devices. In the absence of detailed knowledge about device and circuit radiation response, a two-point standard test is proposed to ensure space surviability of CMOS circuits: a Co-60 irradiation and test to screen against oxide-trapped charge related failures, and an additional rebound test to screen against interface-trap related failures. Testing implications for bipolar technologies are also discussed

Revisiting Low-Dose Total Skin Electron Beam Therapy in Mycosis Fungoides

Energy Technology Data Exchange (ETDEWEB)

Harrison, Cameron, E-mail: cameronh@stanford.edu [Department of Dermatology, Stanford Cancer Center, Stanford, California (United States); Young, James; Navi, Daniel [Department of Dermatology, Stanford Cancer Center, Stanford, California (United States); Riaz, Nadeem [Department of Radiation Oncology, Stanford Cancer Center, Stanford, California (United States); Lingala, Bharathi; Kim, Youn [Department of Dermatology, Stanford Cancer Center, Stanford, California (United States); Hoppe, Richard [Department of Radiation Oncology, Stanford Cancer Center, Stanford, California (United States)

2011-11-15

Purpose: Total skin electron beam therapy (TSEBT) is a highly effective treatment for mycosis fungoides (MF). The standard course consists of 30 to 36 Gy delivered over an 8- to 10-week period. This regimen is time intensive and associated with significant treatment-related toxicities including erythema, desquamation, anhydrosis, alopecia, and xerosis. The aim of this study was to identify a lower dose alternative while retaining a favorable efficacy profile. Methods and Materials: One hundred two MF patients were identified who had been treated with an initial course of low-dose TSEBT (5-<30 Gy) between 1958 and 1995. Patients had a T stage classification of T2 (generalized patch/plaque, n = 51), T3 (tumor, n = 29), and T4 (erythrodermic, n = 22). Those with extracutaneous disease were excluded. Results: Overall response (OR) rates (>50% improvement) were 90% among patients with T2 to T4 disease receiving 5 to <10 Gy (n = 19). In comparison, OR rates between the 10 to <20 Gy and 20 to <30 Gy subgroups were 98% and 97%, respectively. There was no significant difference in median progression free survival (PFS) in T2 and T3 patients when stratified by dose group, and PFS in each was comparable to that of the standard dose. Conclusions: OR rates associated with low-dose TSEBT in the ranges of 10 to <20 Gy and 20 to <30 Gy are comparable to that of the standard dose ({>=} 30 Gy). Efficacy measures including OS, PFS, and RFS are also favorable. Given that the efficacy profile is similar between 10 and <20 Gy and 20 and <30 Gy, the utility of TSEBT within the lower dose range of 10 to <20 Gy merits further investigation, especially in the context of combined modality treatment.

SU-E-T-196: Comparative Analysis of Surface Dose Measurements Using MOSFET Detector and Dose Predicted by Eclipse - AAA with Varying Dose Calculation Grid Size

Energy Technology Data Exchange (ETDEWEB)

Badkul, R; Nejaiman, S; Pokhrel, D; Jiang, H; Kumar, P [University of Kansas Medical Center, Kansas City, KS (United States)

2015-06-15

Purpose: Skin dose can be the limiting factor and fairly common reason to interrupt the treatment, especially for treating head-and-neck with Intensity-modulated-radiation-therapy(IMRT) or Volumetrically-modulated - arc-therapy (VMAT) and breast with tangentially-directed-beams. Aim of this study was to investigate accuracy of near-surface dose predicted by Eclipse treatment-planning-system (TPS) using Anisotropic-Analytic Algorithm (AAA)with varying calculation grid-size and comparing with metal-oxide-semiconductor-field-effect-transistors(MOSFETs)measurements for a range of clinical-conditions (open-field,dynamic-wedge, physical-wedge, IMRT,VMAT). Methods: QUASAR™-Body-Phantom was used in this study with oval curved-surfaces to mimic breast, chest wall and head-and-neck sites.A CT-scan was obtained with five radio-opaque markers(ROM) placed on the surface of phantom to mimic the range of incident angles for measurements and dose prediction using 2mm slice thickness.At each ROM, small structure(1mmx2mm) were contoured to obtain mean-doses from TPS.Calculations were performed for open-field,dynamic-wedge,physical-wedge,IMRT and VMAT using Varian-21EX,6&15MV photons using twogrid-sizes:2.5mm and 1mm.Calibration checks were performed to ensure that MOSFETs response were within ±5%.Surface-doses were measured at five locations and compared with TPS calculations. Results: For 6MV: 2.5mm grid-size,mean calculated doses(MCD)were higher by 10%(±7.6),10%(±7.6),20%(±8.5),40%(±7.5),30%(±6.9) and for 1mm grid-size MCD were higher by 0%(±5.7),0%(±4.2),0%(±5.5),1.2%(±5.0),1.1% (±7.8) for open-field,dynamic-wedge,physical-wedge,IMRT,VMAT respectively.For 15MV: 2.5mm grid-size,MCD were higher by 30%(±14.6),30%(±14.6),30%(±14.0),40%(±11.0),30%(±3.5)and for 1mm grid-size MCD were higher by 10% (±10.6), 10%(±9.8),10%(±8.0),30%(±7.8),10%(±3.8) for open-field, dynamic-wedge, physical-wedge, IMRT, VMAT respectively.For 6MV, 86% and 56% of all measured values

Compendium of Total Ionizing Dose and Displacement Damage for Candidate Spacecraft Electronics for NASA

Science.gov (United States)

Cochran, Donna J.; Boutte, Alvin J.; Chen, Dakai; Pellish, Jonathan A.; Ladbury, Raymond L.; Casey, Megan C.; Campola, Michael J.; Wilcox, Edward P.; Obryan, Martha V.; LaBel, Kenneth A.;

Total effective dose equivalent associated with fixed uranium surface contamination

International Nuclear Information System (INIS)

Bogard, J.S.; Hamm, R.N.; Ashley, J.C.; Turner, J.E.; England, C.A.; Swenson, D.E.; Brown, K.S.

1997-04-01

This report provides the technical basis for establishing a uranium fixed-contamination action level, a fixed uranium surface contamination level exceeding the total radioactivity values of Appendix D of Title 10, Code of Federal Regulations, part 835 (10CFR835), but below which the monitoring, posting, and control requirements for Radiological Areas are not required for the area of the contamination. An area of fixed uranium contamination between 1,000 dpm/100 cm 2 and that level corresponding to an annual total effective dose equivalent (TEDE) of 100 mrem requires only routine monitoring, posting to alert personnel of the contamination, and administrative control. The more extensive requirements for monitoring, posting, and control designated by 10CFR835 for Radiological Areas do not have to be applied for these intermediate fixed-contamination levels

Time- and dose-dependent effects of total-body ionizing radiation on muscle stem cells

Science.gov (United States)

Masuda, Shinya; Hisamatsu, Tsubasa; Seko, Daiki; Urata, Yoshishige; Goto, Shinji; Li, Tao-Sheng; Ono, Yusuke

2015-01-01

Exposure to high levels of genotoxic stress, such as high-dose ionizing radiation, increases both cancer and noncancer risks. However, it remains debatable whether low-dose ionizing radiation reduces cellular function, or rather induces hormetic health benefits. Here, we investigated the effects of total-body γ-ray radiation on muscle stem cells, called satellite cells. Adult C57BL/6 mice were exposed to γ-radiation at low- to high-dose rates (low, 2 or 10 mGy/day; moderate, 50 mGy/day; high, 250 mGy/day) for 30 days. No hormetic responses in proliferation, differentiation, or self-renewal of satellite cells were observed in low-dose radiation-exposed mice at the acute phase. However, at the chronic phase, population expansion of satellite cell-derived progeny was slightly decreased in mice exposed to low-dose radiation. Taken together, low-dose ionizing irradiation may suppress satellite cell function, rather than induce hormetic health benefits, in skeletal muscle in adult mice. PMID:25869487

Dose and dose rate effects of whole-body gamma-irradiation: II. Hematological variables and cytokines

Science.gov (United States)

Gridley, D. S.; Pecaut, M. J.; Miller, G. M.; Moyers, M. F.; Nelson, G. A.

2001-01-01

The goal of part II of this study was to evaluate the effects of gamma-radiation on circulating blood cells, functional characteristics of splenocytes, and cytokine expression after whole-body irradiation at varying total doses and at low- and high-dose-rates (LDR, HDR). Young adult C57BL/6 mice (n = 75) were irradiated with either 1 cGy/min or 80 cGy/min photons from a 60Co source to cumulative doses of 0.5, 1.5, and 3.0 Gy. The animals were euthanized at 4 days post-exposure for in vitro assays. Significant dose- (but not dose-rate-) dependent decreases were observed in erythrocyte and blood leukocyte counts, hemoglobin, hematocrit, lipopolysaccharide (LPS)-induced 3H-thymidine incorporation, and interleukin-2 (IL-2) secretion by activated spleen cells when compared to sham-irradiated controls (p factor-beta 1 (TGF-beta 1) and splenocyte secretion of tumor necrosis factor-alpha (TNF-alpha) were not affected by either the dose or dose rate of radiation. The data demonstrate that the responses of blood and spleen were largely dependent upon the total dose of radiation employed and that an 80-fold difference in the dose rate was not a significant factor in the great majority of measurements.

Analytical models for total dose ionization effects in MOS devices.

Energy Technology Data Exchange (ETDEWEB)

Campbell, Phillip Montgomery; Bogdan, Carolyn W.

2008-08-01

MOS devices are susceptible to damage by ionizing radiation due to charge buildup in gate, field and SOI buried oxides. Under positive bias holes created in the gate oxide will transport to the Si / SiO{sub 2} interface creating oxide-trapped charge. As a result of hole transport and trapping, hydrogen is liberated in the oxide which can create interface-trapped charge. The trapped charge will affect the threshold voltage and degrade the channel mobility. Neutralization of oxidetrapped charge by electron tunneling from the silicon and by thermal emission can take place over long periods of time. Neutralization of interface-trapped charge is not observed at room temperature. Analytical models are developed that account for the principal effects of total dose in MOS devices under different gate bias. The intent is to obtain closed-form solutions that can be used in circuit simulation. Expressions are derived for the aging effects of very low dose rate radiation over long time periods.

Fast method for in-flight estimation of total dose from protons and electrons using RADE Minstrument on JUICE

Science.gov (United States)

Hajdas, Wojtek; Mrigakshi, Alankrita; Xiao, Hualin

2017-04-01

The primary concern of the ESA JUICE mission to Jupiter is the harsh particle radiation environment. Ionizing particles introduce radiation damage by total dose effects, displacement damages or single events effects. Therefore, both the total ionizing dose and the displacement damage equivalent fluence must be assessed to alert spacecraft and its payload as well as to quantify radiation levels for the entire mission lifetime. We present a concept and implementations steps for simplified method used to compute in flight a dose rate and total dose caused by protons. We also provide refinement of the method previously developed for electrons. The dose rates values are given for predefined active volumes located behind layers of materials with known thickness. Both methods are based on the electron and proton flux measurements provided by the Electron and Proton Detectors inside the Radiation Hard Electron Monitor (RADEM) located on-board of JUICE. The trade-off between method accuracy and programming limitations for in-flight computations are discussed. More comprehensive and precise dose rate computations based on detailed analysis of all stack detectors will be made during off-line data processing. It will utilize full spectral unfolding from all RADEM detector subsystems.

SEIR Model of Rumor Spreading in Online Social Network with Varying Total Population Size

International Nuclear Information System (INIS)

Dong Suyalatu; Deng Yan-Bin; Huang Yong-Chang

2017-01-01

Based on the infectious disease model with disease latency, this paper proposes a new model for the rumor spreading process in online social network. In this paper what we establish an SEIR rumor spreading model to describe the online social network with varying total number of users and user deactivation rate. We calculate the exact equilibrium points and reproduction number for this model. Furthermore, we perform the rumor spreading process in the online social network with increasing population size based on the original real world Facebook network. The simulation results indicate that the SEIR model of rumor spreading in online social network with changing total number of users can accurately reveal the inherent characteristics of rumor spreading process in online social network . (paper)

Secondary radiation dose during high-energy total body irradiation

Energy Technology Data Exchange (ETDEWEB)

Janiszewska, M.; Raczkowski, M. [Lower Silesian Oncology Center, Medical Physics Department, Wroclaw (Poland); Polaczek-Grelik, K. [University of Silesia, Medical Physics Department, Katowice (Poland); Szafron, B.; Konefal, A.; Zipper, W. [University of Silesia, Department of Nuclear Physics and Its Applications, Katowice (Poland)

2014-05-15

The goal of this work was to assess the additional dose from secondary neutrons and γ-rays generated during total body irradiation (TBI) using a medical linac X-ray beam. Nuclear reactions that occur in the accelerator construction during emission of high-energy beams in teleradiotherapy are the source of secondary radiation. Induced activity is dependent on the half-lives of the generated radionuclides, whereas neutron flux accompanies the treatment process only. The TBI procedure using a 18 MV beam (Clinac 2100) was considered. Lateral and anterior-posterior/posterior-anterior fractions were investigated during delivery of 2 Gy of therapeutic dose. Neutron and photon flux densities were measured using neutron activation analysis (NAA) and semiconductor spectrometry. The secondary dose was estimated applying the fluence-to-dose conversion coefficients. The main contribution to the secondary dose is associated with fast neutrons. The main sources of γ-radiation are the following: {sup 56}Mn in the stainless steel and {sup 187}W of the collimation system as well as positron emitters, activated via (n,γ) and (γ,n) processes, respectively. In addition to 12 Gy of therapeutic dose, the patient could receive 57.43 mSv in the studied conditions, including 4.63 μSv from activated radionuclides. Neutron dose is mainly influenced by the time of beam emission. However, it is moderated by long source-surface distances (SSD) and application of plexiglass plates covering the patient body during treatment. Secondary radiation gives the whole body a dose, which should be taken into consideration especially when one fraction of irradiation does not cover the whole body at once. (orig.) [German] Die zusaetzliche Dosis durch sekundaere Neutronen- und γ-Strahlung waehrend der Ganzkoerperbestrahlung mit Roentgenstrahlung aus medizinischen Linearbeschleunigern wurde abgeschaetzt. Bei der Emission hochenergetischer Strahlen zur Teletherapie finden hauptsaechlich im Beschleuniger

Fractionated total body irradiation and autologous bone marrow transplantation in dogs: Hemopoietic recovery after various marrow cell doses

International Nuclear Information System (INIS)

Bodenburger, U.; Kolb, H.J.; Thierfelder, S.; Netzel, B.; Schaeffer, E.; Kolb, H.

1980-01-01

Hemopoietic recovery was studied in dogs given 2400 R fractionated total body irradiation within one week and graded doses of cryopreserved autologous bone marrow. Complete hemopoietic recovery including histology was observed after this dose and sufficient doses of marrow cells. Doses of more than 5.5 x 10 7 mononuclear marrow cells/kg body weight were sufficient for complete recovery in all dogs, 1.5 to 5.5 x 10 7 cells/kg were effective in some of the dogs and less than 1.5 x 10 7 cells/kg were insufficient for complete recovery. Similarly, more than 30000 CFUsub(c)/kg body weight were required for hemopoietic recovery. The optimal marrow cell dose which has been defined as the minimal dose required for the earliest possible recovery of leukocyte and platelet counts was 7-8 x 10 7 mononuclear marrow cells/kg body weight. It has been concluded that fractionated total body irradiation with 2400 R dose not require greater doses of marrow cells for hemopoietic reconstitution than lower single doses and that the hemopoietic microenvironment is not persistently disturbed after this dose. (author)

Modelling normal tissue isoeffect distribution in conformal radiotherapy of glioblastoma provides an alternative dose escalation pattern through hypofractionation without reducing the total dose

International Nuclear Information System (INIS)

Mangel, L.; Skriba, Z.; Major, T.; Polgar, C.; Fodor, J.; Somogyi, A.; Nemeth, G.

2002-01-01

The purpose of this study was to prove that by using conformal external beam radiotherapy (RT) normal brain structures can be protected even when applying an alternative approach of biological dose escalation: hypofractionation (HOF) without total dose reduction (TDR). Traditional 2-dimensional (2D) and conformal 3-dimensional (3D) treatment plans were prepared for 10 gliomas representing the subanatomical sites of the supratentorial brain. Isoeffect distributions were generated by the biologically effective dose (BED) formula to analyse the effect of conventionally fractionated (CF) and HOF schedules on both the spatial biological dose distribution and biological dose-volume histograms. A comparison was made between 2D-CF (2.0 Gy/day) and 3D-HOF (2.5 Gy/day) regimens, applying the same 60 Gy total doses. Integral biologically effective dose (IBED) and volumes received biologically equivalent to a dose of 54 Gy or more (V-BED54) were calculated for the lower and upper brain stem as organs of risk. The IBED values were lower with the 3D-HOF than with the 2D-CF schedule in each tumour location, means 22.7±17.1 and 40.4±16.9 in Gy, respectively (p<0.0001). The V-BED54 values were also smaller or equal in 90% of the cases favouring the 3D-HOF scheme. The means were 2.7±4.8 ccm for 3D-HOF and 10.7±12.7 ccm for 2D-CF (p=0.0006). Our results suggest that with conformal RT, fraction size can gradually be increased. HOF radiotherapy regimens without TDR shorten the treatment time and seem to be an alternative way of dose escalation in the treatment of glioblastoma

Modelling normal tissue isoeffect distribution in conformal radiotherapy of glioblastoma provides an alternative dose escalation pattern through hypofractionation without reducing the total dose

Energy Technology Data Exchange (ETDEWEB)

Mangel, L.; Skriba, Z.; Major, T.; Polgar, C.; Fodor, J.; Somogyi, A.; Nemeth, G. [National Research Inst. for Radiobiology and Radiohygiene, Budapest (Hungary)

2002-04-01

The purpose of this study was to prove that by using conformal external beam radiotherapy (RT) normal brain structures can be protected even when applying an alternative approach of biological dose escalation: hypofractionation (HOF) without total dose reduction (TDR). Traditional 2-dimensional (2D) and conformal 3-dimensional (3D) treatment plans were prepared for 10 gliomas representing the subanatomical sites of the supratentorial brain. Isoeffect distributions were generated by the biologically effective dose (BED) formula to analyse the effect of conventionally fractionated (CF) and HOF schedules on both the spatial biological dose distribution and biological dose-volume histograms. A comparison was made between 2D-CF (2.0 Gy/day) and 3D-HOF (2.5 Gy/day) regimens, applying the same 60 Gy total doses. Integral biologically effective dose (IBED) and volumes received biologically equivalent to a dose of 54 Gy or more (V-BED54) were calculated for the lower and upper brain stem as organs of risk. The IBED values were lower with the 3D-HOF than with the 2D-CF schedule in each tumour location, means 22.7{+-}17.1 and 40.4{+-}16.9 in Gy, respectively (p<0.0001). The V-BED54 values were also smaller or equal in 90% of the cases favouring the 3D-HOF scheme. The means were 2.7{+-}4.8 ccm for 3D-HOF and 10.7{+-}12.7 ccm for 2D-CF (p=0.0006). Our results suggest that with conformal RT, fraction size can gradually be increased. HOF radiotherapy regimens without TDR shorten the treatment time and seem to be an alternative way of dose escalation in the treatment of glioblastoma.

Preliminary estimation of minimum target dose in intracavitary radiotherapy for cervical cancer

Energy Technology Data Exchange (ETDEWEB)

Ohara, Kiyoshi; Oishi-Tanaka, Yumiko; Sugahara, Shinji; Itai, Yuji [Tsukuba Univ., Ibaraki (Japan). Inst. of Clinical Medicine

2001-08-01

In intracavitary radiotherapy (ICRT) for cervical cancer, minimum target dose (D{sub min}) will pertain to local disease control more directly than will reference point A dose (D{sub A}). However, ICRT has been performed traditionally without specifying D{sub min} since the target volume was not identified. We have estimated D{sub min} retrospectively by identifying tumors using magnetic resonance (MR) images. Pre- and posttreatment MR images of 31 patients treated with high-dose-rate ICRT were used. ICRT was performed once weekly at 6.0 Gy D{sub A}, and involved 2-5 insertions for each patient, 119 insertions in total. D{sub min} was calculated arbitrarily simply at the point A level using the tumor width (W{sub A}) to compare with D{sub A}. W{sub A} at each insertion was estimated by regression analysis with pre- and posttreatment W{sub A}. D{sub min} for each insertion varied from 3.0 to 46.0 Gy, a 16-fold difference. The ratio of total D{sub min} to total D{sub A} for each patient varied from 0.5 to 6.5. Intrapatient D{sub min} difference between the initial insertion and final insertion varied from 1.1 to 3.4. Preliminary estimation revealed that D{sub min} varies widely under generic dose prescription. Thorough D{sub min} specification will be realized when ICRT-applicator insertion is performed under MR imaging. (author)

Tumor significant dose

International Nuclear Information System (INIS)

Supe, S.J.; Nagalaxmi, K.V.; Meenakshi, L.

1983-01-01

In the practice of radiotherapy, various concepts like NSD, CRE, TDF, and BIR are being used to evaluate the biological effectiveness of the treatment schedules on the normal tissues. This has been accepted as the tolerance of the normal tissue is the limiting factor in the treatment of cancers. At present when various schedules are tried, attention is therefore paid to the biological damage of the normal tissues only and it is expected that the damage to the cancerous tissues would be extensive enough to control the cancer. Attempt is made in the present work to evaluate the concent of tumor significant dose (TSD) which will represent the damage to the cancerous tissue. Strandquist in the analysis of a large number of cases of squamous cell carcinoma found that for the 5 fraction/week treatment, the total dose required to bring about the same damage for the cancerous tissue is proportional to T/sup -0.22/, where T is the overall time over which the dose is delivered. Using this finding the TSD was defined as DxN/sup -p/xT/sup -q/, where D is the total dose, N the number of fractions, T the overall time p and q are the exponents to be suitably chosen. The values of p and q are adjusted such that p+q< or =0.24, and p varies from 0.0 to 0.24 and q varies from 0.0 to 0.22. Cases of cancer of cervix uteri treated between 1978 and 1980 in the V. N. Cancer Centre, Kuppuswamy Naidu Memorial Hospital, Coimbatore, India were analyzed on the basis of these formulations. These data, coupled with the clinical experience, were used for choice of a formula for the TSD. Further, the dose schedules used in the British Institute of Radiology fraction- ation studies were also used to propose that the tumor significant dose is represented by DxN/sup -0.18/xT/sup -0.06/

Relative effect of radiation dose rate on hemopoietic and nonhemopoietic lethality of total-body irradiation

International Nuclear Information System (INIS)

Peters, L.J.; McNeill, J.; Karolis, C.; Thames, H.D. Jr.; Travis, E.L.

1986-01-01

Experiments were undertaken to determine the influence of dose rate on the toxicity of total-body irrdiation (TBI) with and without syngeneic bone-marrow rescue in mice. The results showed a much greater dose-rate dependence for death from nonhemopoietic toxicity than from bone-marrow ablation, with the ratio of LD 50 's increasing from 1.73 at 25 cGy/min to 2.80 at 1 cGy/min. At the higher dose rates, dose-limiting nonhemopoietic toxicity resulted from late organ injury, affecting the lungs, kidneys, and liver. At 1 cGy/min the major dose-limiting nonhemopoietic toxicity was acute gastrointestinal injury. The implications of these results in the context of TBI in preparation for bone-marrow transplantation are discussed. 15 refs., 4 figs

Dose characteristics of total-skin electron-beam irradiation with six-dual electron fields

International Nuclear Information System (INIS)

Choi, Tae Jin; Kim, Jin Hee; Kim, Ok Bae

1998-01-01

To obtain the uniform dose at limited depth to entire surface of the body, the dose characteristics of degraded electron beam of the large target-skin distance and the dose distribution of the six-dual electron fields were investigated. The experimental dose distributions included the depth dose curve, spatial dose and attenuated electron beam were determined with 300 cm of Target-Skin Distance (TSD) and full collimator size (35x35 cm 2 on TSD 100 cm) in 4 MeV electron beam energy. Actual collimated field size of 105 cmx105 cm at the distance of 300 cm could include entire hemibody. A patient was standing on step board with hands up and holding the pole to stabilize his/her positions for the six-dual fields technique. As a scatter-degrader, 0.5 cm of acrylic plate was inserted at 20 cm from the body surface on the electron beam path to induce ray scattering and to increase the skin dose. The Full Width at Half Maximum(FWHM) of dose profile was 130 cm in large field of 105x105 cm 2 . The width of 100±10% of the resultant dose from two adjacent fields which were separated at 25 cm from field edge for obtaining the dose uniformity was extended to 186 cm. The depth of maximum dose lies at 5 mm and the 80% depth dose lies between 7 and 8 mm for the degraded electron beam by using the 0.5 cm thickness of acrylic absorber. Total skin electron beam irradiation (TSEBI) was carried out using the six dual fields has been developed at Stanford University. The dose distribution in TSEBI showed relatively uniform around the flat region of skin except the protruding and deeply curvatured portion of the body, which showed excess of dose at the former and less dose at the latter. The percent depth dose, profile curves and superimposed dose distribution were investigated using the degraded using the degraded electron beam through the beam absorber. The dose distribution obtained by experiments of TSEBI showed within±10% difference excepts the protruding area of skin which needs a

Composite depth dose measurement for total skin electron (TSE) treatments using radiochromic film

International Nuclear Information System (INIS)

Gamble, Lisa M; Farrell, Thomas J; Jones, Glenn W; Hayward, Joseph E

2003-01-01

Total skin electron (TSE) radiotherapy is routinely used to treat cutaneous T-cell lymphomas and can be implemented using a modified Stanford technique. In our centre, the composite depth dose for this technique is achieved by a combination of two patient positions per day over a three-day cycle, and two gantry angles per patient position. Due to patient morphology, underdosed regions typically occur and have historically been measured using multiple thermoluminescent dosimeters (TLDs). We show that radiochromic film can be used as a two-dimensional relative dosimeter to measure the percent depth dose in TSE radiotherapy. Composite depth dose curves were measured in a cylindrical, polystyrene phantom and compared with TLD data. Both multiple films (1 film per day) and a single film were used in order to reproduce a realistic clinical scenario. First, three individual films were used to measure the depth dose, one per treatment day, and then compared with TLD data; this comparison showed a reasonable agreement. Secondly, a single film was used to measure the dose delivered over three daily treatments and then compared with TLD data; this comparison showed good agreement throughout the depth dose, which includes doses well below 1 Gy. It will be shown that one piece of radiochromic film is sufficient to measure the composite percent depth dose for a TSE beam, hence making radiochromic film a suitable candidate for monitoring underdosed patient regions

Three-dimensional Finite Elements Method simulation of Total Ionizing Dose in 22 nm bulk nFinFETs

Energy Technology Data Exchange (ETDEWEB)

Chatzikyriakou, Eleni, E-mail: ec3g12@soton.ac.uk; Potter, Kenneth; Redman-White, William; De Groot, C.H.

2017-02-15

Highlights: • Simulation of Total Ionizing Dose using the Finite Elements Method. • Carrier generation, transport and trapping in the oxide. • Application in three-dimensional bulk FinFET model of 22 nm node. • Examination of trapped charge in the Shallow Trench Isolation. • Trapped charge dependency of parasitic transistor current. - Abstract: Finite Elements Method simulation of Total Ionizing Dose effects on 22 nm bulk Fin Field Effect Transistor (FinFET) devices using the commercial software Synopsys Sentaurus TCAD is presented. The simulation parameters are extracted by calibrating the charge trapping model to experimental results on 400 nm SiO{sub 2} capacitors irradiated under zero bias. The FinFET device characteristics are calibrated to the Intel 22 nm bulk technology. Irradiation simulations of the transistor performed with all terminals unbiased reveal increased hardness up to a total dose of 1 MRad(SiO{sub 2}).

Effects of varying doses of gamma radiation on locally adapted Tradescantia clone 02 (BNL) (Brookhaven National Laboratory)

International Nuclear Information System (INIS)

Dimaano, Maritess M.; Imperial V, Maria Angelica Liza

1999-03-01

This study determined the effects of gamma radiation on the meiotic cells of Tradescantia bracteata clone 02 (BNL). The flower buds collected were exposed through dosages ranging from 1 Gy to 5 Gy using gamma cell 220 machine (AECL) in a central axis position (c/a) and grown in Peralta's solution for three days. Out of the twenty buds designated for each dosages, ten buds were treated with 0.05% colchicine solution. The occurrence of micronuclei among the irradiated pollen mother cells suggested a linear relation with the quantity of radiation dose. The occurrence of MN among cells increased linearly from 1 Gy until it reached 3 Gy and 4 Gy. Beyond this maximum dose, cells were less responsive to the dose caused by inhibition of cell division, as demonstrated in the buds exposed to 5 Gy. This result was validated through the kruskal-Wallis test, where the computed h value was 3.44 (critical region of X 2 0 . 05 = 9.49) Experimental results also showed chromosomal breaks, sticky chromosomes, and anaphase bridges in the pollen mother cells of irradiated buds. A significant numbers of cells were also found to have micronuclei, which may vary from 1 to 6 per pollen mother cell, and this showed no relationship with radiation dose. (Author)

Dose compensation of the total body irradiation therapy

International Nuclear Information System (INIS)

Lin, J.-P.; Chu, T.-C.; Liu, M.-T.

2001-01-01

The aim of the study is to improve dose uniformity in the body by the compensator-rice and to decrease the dose to the lung by the partial lung block. Rando phantom supine was set up to treat bilateral fields with a 15 MV linear accelerator at 415 cm treatment distance. The experimental procedure included three parts. The first part was the bilateral irradiation without rice compensator, and the second part was with rice compensator. In the third part, rice compensator and partial lung block were both used. The results of thermoluminescent dosimeters measurements indicated that without rice compensator the dose was non-uniform. Contrarily, the average dose homogeneity with rice compensator was measured within ±5%, except for the thorax region. Partial lung block can reduce the dose which the lung received. This is a simple method to improve the dose homogeneity and to reduce the lung dose received. The compensator-rice is cheap, and acrylic boxes are easy to obtain. Therefore, this technique is suitable for more studies

Dose and dose rate effects of whole-body gamma-irradiation: II. Hematological variables and cytokines

Science.gov (United States)

Gridley, D. S.; Pecaut, M. J.; Miller, G. M.; Moyers, M. F.; Nelson, G. A.

2001-01-01

The goal of part II of this study was to evaluate the effects of gamma-radiation on circulating blood cells, functional characteristics of splenocytes, and cytokine expression after whole-body irradiation at varying total doses and at low- and high-dose-rates (LDR, HDR). Young adult C57BL/6 mice (n = 75) were irradiated with either 1 cGy/min or 80 cGy/min photons from a 60Co source to cumulative doses of 0.5, 1.5, and 3.0 Gy. The animals were euthanized at 4 days post-exposure for in vitro assays. Significant dose- (but not dose-rate-) dependent decreases were observed in erythrocyte and blood leukocyte counts, hemoglobin, hematocrit, lipopolysaccharide (LPS)-induced 3H-thymidine incorporation, and interleukin-2 (IL-2) secretion by activated spleen cells when compared to sham-irradiated controls (p < 0.05). Basal proliferation of leukocytes in the blood and spleen increased significantly with increasing dose (p < 0.05). Significant dose rate effects were observed only in thrombocyte counts. Plasma levels of transforming growth factor-beta 1 (TGF-beta 1) and splenocyte secretion of tumor necrosis factor-alpha (TNF-alpha) were not affected by either the dose or dose rate of radiation. The data demonstrate that the responses of blood and spleen were largely dependent upon the total dose of radiation employed and that an 80-fold difference in the dose rate was not a significant factor in the great majority of measurements.

Design of spray dried insulin microparticles to bypass deposition in the extrathoracic region and maximize total lung dose.

Science.gov (United States)

Ung, Keith T; Rao, Nagaraja; Weers, Jeffry G; Huang, Daniel; Chan, Hak-Kim

2016-09-25

Inhaled drugs all too often deliver only a fraction of the emitted dose to the target lung site due to deposition in the extrathoracic region (i.e., mouth and throat), which can lead to increased variation in lung exposure, and in some instances increases in local and systemic side effects. For aerosol medications, improved targeting to the lungs may be achieved by tailoring the micromeritic properties of the particles (e.g., size, density, rugosity) to minimize deposition in the mouth-throat and maximize the total lung dose. This study evaluated a co-solvent spray drying approach to modulate particle morphology and dose delivery characteristics of engineered powder formulations of insulin microparticles. The binary co-solvent system studied included water as the primary solvent mixed with an organic co-solvent, e.g., ethanol. Factors such as the relative rate of evaporation of each component of a binary co-solvent mixture, and insulin solubility in each component were considered in selecting feedstock compositions. A water-ethanol co-solvent mixture with a composition range considered suitable for modulating particle shell formation during drying was selected for experimental investigation. An Alberta Idealized Throat model was used to evaluate the in vitro total lung dose of a series of spray dried insulin formulations engineered with different bulk powder properties and delivered with two prototype inhalers that fluidize and disperse powder using different principles. The in vitro total lung dose of insulin microparticles was improved and favored for powders with low bulk density and small primary particle size, with reduction of deposition in the extrathoracic region. The results demonstrated that a total lung dose >95% of the delivered dose can be achieved with engineered particles, indicating a high degree of lung targeting, almost completely bypassing deposition in the mouth-throat. Copyright © 2016 Elsevier B.V. All rights reserved.

SEIR Model of Rumor Spreading in Online Social Network with Varying Total Population Size

Science.gov (United States)

Dong, Suyalatu; Deng, Yan-Bin; Huang, Yong-Chang

2017-10-01

Based on the infectious disease model with disease latency, this paper proposes a new model for the rumor spreading process in online social network. In this paper what we establish an SEIR rumor spreading model to describe the online social network with varying total number of users and user deactivation rate. We calculate the exact equilibrium points and reproduction number for this model. Furthermore, we perform the rumor spreading process in the online social network with increasing population size based on the original real world Facebook network. The simulation results indicate that the SEIR model of rumor spreading in online social network with changing total number of users can accurately reveal the inherent characteristics of rumor spreading process in online social network. Supported by National Natural Science Foundation of China under Grant Nos. 11275017 and 11173028

Total Skin Electron Beam Therapy in the Treatment of Mycosis Fungoides: A Review of Conventional and Low-Dose Regimens.

Science.gov (United States)

Chowdhary, Mudit; Chhabra, Arpit M; Kharod, Shivam; Marwaha, Gaurav

2016-12-01

Mycosis fungoides (MF) is the most prevalent subtype of cutaneous T-cell lymphoma, which is characterized by the proliferation of CD4 + T cells. While often an indolent disease, most patients eventually develop progression from isolated patches to tumors and finally nodal or visceral involvement. Treatment choice is largely based on disease burden, though prognostic factors such as disease stage, patient age, and extracutaneous involvement must be taken into consideration. Radiotherapy represents one of the most effective therapeutic modalities in the treatment of MF. Lymphocytes are exquisitely radiosensitive, and excellent responses are observed even with low doses of radiation. Total skin electron beam therapy (TSEBT) is a special technique that allows for the homogenous irradiation of the entire skin. There are well-documented radiation dose-response relationships for achieving a complete response. As such, TSEBT doses ≥ 30 Gy comprise the current standard of care. Although highly effective, most patients experience recurrent disease even after conventional-dose (≥ 30 Gy) TSEBT. In addition, toxicity is cumulatively dose dependent, and there is reluctance to administer multiple courses of conventional-dose TSEBT. Consequently, there has been renewed interest in determining the utility of TSEBT at lower total (≤ 30 Gy) doses. Advantages of low-total-dose (with standard dose per fraction) TSEBT include a shortened treatment course, the potential to minimize the risk of adverse events, and the opportunity to allow for retreatment in cases of disease recurrence. This comprehensive review compares the impact of different TSEBT dosing schemes on clinical outcomes of MF. Copyright © 2016 Elsevier Inc. All rights reserved.

Intralesional Versus Oral Chloroquine in Cutaneous Leishmaniasis: Comparison of Outcome, Duration of Treatment and Total Dose of Drug

International Nuclear Information System (INIS)

Hanif, M. M.; Akram, K.; Mustafa, G.

2016-01-01

Objective: To compare intralesional versus oral chloroquine in cutaneous leishmaniasis and determine the cure rate, duration of treatment, and total dose of drug. Study Design: Randomized controlled study. Place and Duration of Study: Department of Dermatology, Sheikh Zayed Medical College/Hospital, Rahim Yar Khan, from November 2013 to June 2014. Methodology: Consecutive 86 patients of cutaneous leishmaniasis, with single to multiple lesions of various sizes were enrolled and divided randomly into group A and B for the purpose of intralesional and oral chloroquine administration, respectively to compare the effect of the two routes on duration of treatment and total dose of the drug. SPSS version 16 was used for data analysis after data entry into it. Quantitative variables like, duration, cost and total dose of treatment were calculated as mean and standard deviation and compared by using T-test. P-value of less than 0.05 was taken as significant. Results: Cure rate was 100% in both groups towards the end of treatment. Mean duration of treatment was 9.17 ± 3 weeks in intralesional (A) group as against 11.37 ± 3 weeks in oral (B) group (p = 0.0028). Mean total dose of the drug given to each patient in group A was 5.8 ± 0.5 gm and in group B, it was 19.2 ± 1.5 gm, which is significantly higher (p=0.001). The total cost of treatment in group A was Rs. 90 ± 8 and in group B it was Rs. 91 ± 1 (p=0.446). Conclusion: Duration of treatment is significantly shorter and total dose is lesser with intralesional compared to oral chloroquine in treatment of cutaneous leishmaniasis. (author)

Recent Total Ionizing Dose and Displacement Damage Compendium of Candidate Electronics for NASA Space Systems

Science.gov (United States)

Cochran, Donna J.; Boutte, Alvin J.; Campola, Michael J.; Carts, Martin A.; Casey, Megan C.; Chen, Dakai; LaBel, Kenneth A.; Ladbury, Raymond L.; Lauenstein, Jean-Marie; Marshall, Cheryl J.;

Effect of high-dose preoperative methylprednisolone on pain and recovery after total knee arthroplasty: a randomized, placebo-controlled trial

DEFF Research Database (Denmark)

Lunn, Troels; Kristensen, Billy Bjarne; Andersen, Lasse

2011-01-01

Total knee arthroplasty (TKA) is associated with severe pain and inflammation despite an extensive multimodal analgesic approach, but the effect of high-dose glucocorticoid administration has not been studied.......Total knee arthroplasty (TKA) is associated with severe pain and inflammation despite an extensive multimodal analgesic approach, but the effect of high-dose glucocorticoid administration has not been studied....

Hematological toxicity in radioimmunotherapy is predicted both by the computed absorbed whole body dose (cGy) and by the administered dose (mCi)

International Nuclear Information System (INIS)

Marquez, Sheri D.; Knox, Susan J.; Trisler, Kirk D.; Goris, Michael L.

1997-01-01

-90 anti-CD20 antibody treated group, in which the estimated whole body dose varied (D(cGy)), the decrease in these values was predicted by the linear (zero intercept) equations: DWBC = 0.01158 D(cGy) + 0.05247 D(mCi), DPLAT = 0.1476 D(cGy) + 3.043 D(mCi), and DN=0.0047 D(cGy)+0.0507D(mCi). In the Iodine-131 anti-CD20 antibody treated group, where D(cGy) was constant and equal to 75 cGy, the variation in toxicity was predicted by the linear equation DPLAT = -241 + 5.53 D(mCi), with F=12.184 (p<0.01) and DWBC = -2.62 + 0.0757 D (mCi), with F=3.14 (NS). Conclusion: The results suggest that the total absorbed dose is not an absolute predictor of effect, but in this restricted data set a significant predominant effect of the administered dose on toxicity could not be demonstrated either. The data however do not invalidate the theoretical view that 1) with internal radionuclides a large fraction of the total absorbed dose is delivered at very low dose rates, which may be too low for any appreciable effect, and 2) if variation in the kinetics of the agents lead to an adaptation of the administered dose, the initial dose rate is affected. The therapeutic and toxic effects of RIT are probably a function of both the total dose and the dose rate. Further optimization of this therapy needs to take this into consideration

The effect of low-dose total body irradiation on tumor control

International Nuclear Information System (INIS)

Sakamoto, Kiyohiko; Miyamoto, Miyako; Watabe, Nobuyuki.

1987-01-01

Total body irradiation (TBI) is considered to bring about an immunosuppressive effect on an organism, on the basis of data obtained from sublethal doses of TBI. However, there are no data on how low-dose TBI affects an organism. Over the last five years, we have been studying the effects of low-dose TBI on normal or tumor-bearing mice and the immunological background of these effects. In experimental studies, an increase in the TD50 value (the number of cells required for a tumor incidence of 50 %) in mice exposed to 10 rad was recognized and showed a remarkable increase at 6 hours to 15 hours after irradiation. TBI of 10 rad also showed an enhancement effect on tumor cell killing when given 12 hours before local tumor irradiation. In order to clarify the mechanism of this kind of effect, some immunological studies were performed using several immunological procedures, and the results suggested that 10 rad of TBI caused increasing tumor immunity in irradiated mice. Clinical trials in some patients with advanced tumors are now being undertaken on the basis of these experimental data, and the effect of TBI on tumor control appears promising, although it is too early to draw conclusions. (author)

Synergistic effects of total ionizing dose on single event upset sensitivity in static random access memory under proton irradiation

International Nuclear Information System (INIS)

Xiao Yao; Guo Hong-Xia; Zhang Feng-Qi; Zhao Wen; Wang Yan-Ping; Zhang Ke-Ying; Ding Li-Li; Luo Yin-Hong; Wang Yuan-Ming; Fan Xue

2014-01-01

Synergistic effects of the total ionizing dose (TID) on the single event upset (SEU) sensitivity in static random access memories (SRAMs) were studied by using protons. The total dose was cumulated with high flux protons during the TID exposure, and the SEU cross section was tested with low flux protons at several cumulated dose steps. Because of the radiation-induced off-state leakage current increase of the CMOS transistors, the noise margin became asymmetric and the memory imprint effect was observed. (interdisciplinary physics and related areas of science and technology)

Total-dose hardness assurance for low earth orbit

International Nuclear Information System (INIS)

Maurer, R.H.; Suter, J.J.

1987-01-01

The Low Earth Orbit radiation environment has two significant characteristics that make laboratory simulation exposures difficult: (1) a low dose rate and (2) many cycles of low dose accumulation followed by dose-free annealing. Hardness assurance considerations for this environment are discussed and related to data from the testing of Advanced Low Power Schottky and High-speed CMOS devices

Application of a Pelletron accelerator to study total dose radiation effects on 50 GHz SiGe HBTs

Energy Technology Data Exchange (ETDEWEB)

Praveen, K.C.; Pushpa, N.; Naik, P.S. [Department of Studies in Physics, University of Mysore, Manasagangotri, Mysore 570 006 (India); Cressler, John D. [School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA (United States); Tripathi, Ambuj [Inter University Accelerator Centre (IUAC), New Delhi 110 067 (India); Gnana Prakash, A.P., E-mail: gnanaprakash@physics.uni-mysore.ac.in [Department of Studies in Physics, University of Mysore, Manasagangotri, Mysore 570 006 (India)

2012-02-15

Highlights: Black-Right-Pointing-Pointer Total dose effects of 50 MeV Li3+ ion on 50 GHz SiGe HBTs is investigated. Black-Right-Pointing-Pointer Ion irradiated results were compared with Co-60 gamma results. Black-Right-Pointing-Pointer 50 MeV Li ions create more damage in E-B spacer oxide when compared to Co-60 gamma radiation. Black-Right-Pointing-Pointer Co-60 gamma radiation create more damage in STI oxide when compared to 50 MeV Li ions. Black-Right-Pointing-Pointer Worst case total dose radiation effects can be studied using Pelletron accelerator facilities. - Abstract: We have investigated the effects of 50 MeV lithium ion irradiation on the DC electrical characteristics of first-generation silicon-germanium heterojunction bipolar transistors (50 GHz SiGe HBTs) in the dose range of 600 krad to 100 Mrad. The results of 50 MeV Li{sup 3+} ion irradiation on the SiGe HBTs are compared with 63 MeV proton and Co-60 gamma irradiation results in the same dose range in order to understand the damage induced by different LET species. The radiation response of emitter-base (EB) spacer oxide and shallow trench isolation (STI) oxide to different irradiation types are discussed in this paper. We have also focused on the efficacy in the application of a Pelletron accelerator to study total dose irradiation studies in SiGe HBTs.

Clinical responses after total body irradiation by over permissible dose of γ-rays in one time

International Nuclear Information System (INIS)

Jiang Benrong; Wang Guilin; Liu Huilan; Tang Xingsheng; Ai Huisheng

1990-01-01

The clinical responses of patients after total body over permissilbe dose γ-ray irradiation were observed and analysed. The results showed: when the dose was above 5 cGy, there was some immunological depression, but no significant change in hematopoietic functions. 5 cases showed some transient changes of ECG, perhaps due to vagotonia caused by psychological imbalance, One case vomitted 3-4 times after 28 cGy irradiation, this suggested that a few times of vomitting had no significance in the estimation of the irradiated dose and the whole clinical manifestations must be concretely analysed

Breast dose variability in a bi-racial population undergoing screening mammography

International Nuclear Information System (INIS)

Schubauer-Berigan, M.K.; Baron, L.; Frey, G.D.; Hoel, D.G.

2002-01-01

This study evaluated individual and population dose variability during screening mammography among 570 white and black women in South Carolina, USA. Aspects of dosimetry that were considered include compressed breast thickness (CBT), number of films per screening session, and dose in previous or subsequent sessions. Breast dose was log-normally distributed in the population, with a geometric mean of 6.6 mGy per session. Doses were significantly higher for black women, for women with high CBT or who receive more than two views per breast, and for the mediolateral oblique, compared to the craniocaudal view. No relationship was observed between age and dose. Total dose per breast varied by a factor of 20 across the study population, but the individual's dose varied little among repeat screening sessions, especially after adjusting for the number of films received per session. These results may inform assessments of the projected risks of inducing breast cancer from screening mammography. (author)

Clinical implementation of total skin electron irradiation treatment with a 6 MeV electron beam in high-dose total skin electron mode

International Nuclear Information System (INIS)

Lucero, J. F.; Rojas, J. I.

2016-01-01

Total skin electron irradiation (TSEI) is a special treatment technique offered by modern radiation oncology facilities, given for the treatment of mycosis fungoides, a rare skin disease, which is type of cutaneous T-cell lymphoma [1]. During treatment the patient’s entire skin is irradiated with a uniform dose. The aim of this work is to present implementation of total skin electron irradiation treatment using IAEA TRS-398 code of practice for absolute dosimetry and taking advantage of the use of radiochromic films.

Clinical implementation of total skin electron irradiation treatment with a 6 MeV electron beam in high-dose total skin electron mode

Energy Technology Data Exchange (ETDEWEB)

Lucero, J. F., E-mail: fernando.lucero@hoperadiotherapy.com.gt [Universidad Nacional de Costa Rica, Heredia (Costa Rica); Hope International, Guatemala (Guatemala); Rojas, J. I., E-mail: isaac.rojas@siglo21.cr [Centro Médico Radioterapia Siglo XXI, San José (Costa Rica)

2016-07-07

Total skin electron irradiation (TSEI) is a special treatment technique offered by modern radiation oncology facilities, given for the treatment of mycosis fungoides, a rare skin disease, which is type of cutaneous T-cell lymphoma [1]. During treatment the patient’s entire skin is irradiated with a uniform dose. The aim of this work is to present implementation of total skin electron irradiation treatment using IAEA TRS-398 code of practice for absolute dosimetry and taking advantage of the use of radiochromic films.

Low-dose dual-energy cone-beam CT using a total-variation minimization algorithm

International Nuclear Information System (INIS)

Min, Jong Hwan

2011-02-01

Dual-energy cone-beam CT is an important imaging modality in diagnostic applications, and may also find its use in other application such as therapeutic image guidance. Despite of its clinical values, relatively high radiation dose of dual-energy scan may pose a challenge to its wide use. In this work, we investigated a low-dose, pre-reconstruction type of dual-energy cone-beam CT (CBCT) using a total-variation minimization algorithm for image reconstruction. An empirical dual-energy calibration method was used to prepare material-specific projection data. Raw data at high and low tube voltages are converted into a set of basis functions which can be linearly combined to produce material-specific data using the coefficients obtained through the calibration process. From much fewer views than are conventionally used, material specific images are reconstructed by use of the total-variation minimization algorithm. An experimental study was performed to demonstrate the feasibility of the proposed method using a micro-CT system. We have reconstructed images of the phantoms from only 90 projections acquired at tube voltages of 40 kVp and 90 kVp each. Aluminum-only and acryl-only images were successfully decomposed. We evaluated the quality of the reconstructed images by use of contrast-to-noise ratio and detectability. A low-dose dual-energy CBCT can be realized via the proposed method by greatly reducing the number of projections

Compendium of Current Total Ionizing Dose and Displacement Damage Results from NASA GSFC and NEPP

Science.gov (United States)

Topper, Alyson D.; Campola, Michael J.; Chen, Dakai; Casey, Megan C.; Yau, Ka-Yen; Label, Kenneth A.; Cochran, Donna J.; O'Bryan, Martha V.

2017-01-01

Total ionizing dose and displacement damage testing was performed to characterize and determine the suitability of candidate electronics for NASA space utilization. Devices tested include opto-electronics, digital, analog, linear bipolar devices, and hybrid devices.

Test methods of total dose effects in very large scale integrated circuits

International Nuclear Information System (INIS)

He Chaohui; Geng Bin; He Baoping; Yao Yujuan; Li Yonghong; Peng Honglun; Lin Dongsheng; Zhou Hui; Chen Yusheng

2004-01-01

A kind of test method of total dose effects (TDE) is presented for very large scale integrated circuits (VLSI). The consumption current of devices is measured while function parameters of devices (or circuits) are measured. Then the relation between data errors and consumption current can be analyzed and mechanism of TDE in VLSI can be proposed. Experimental results of 60 Co γ TDEs are given for SRAMs, EEPROMs, FLASH ROMs and a kind of CPU

Ergogenic effect of varied doses of coffee-caffeine on maximal ...

African Journals Online (AJOL)

Endurance performance index (VO2 max, run time & number of exercise laps) were measured and recorded. Result: Repeated measures ANOVA was used to assess the level of significant difference between caffeine doses and placebo dose in VO2 max, run time and number of exercise laps. The result showed no ...

Concentration of total proteins in blood plasma of chickens hatched from irradiated eggs with low dose gamma radiation

International Nuclear Information System (INIS)

Vilic, M.; Kraljevic, P.; Miljanic, S.; Simpraga, M.

2005-01-01

It is known that low-dose ionising radiation may have stimulating effects on chickens. Low doses may also cause changes in the concentration of blood plasma total proteins, glucose and cholesterol in chickens. This study investigates the effects of low dose gamma-radiation on the concentration of total proteins in the blood plasma of chickens hatched from eggs irradiated with a dose of 0.15 Gy on incubation days 7 and 19. Results were compared with the control group (chickens hatched from non-irradiated eggs). After hatching, all other conditions were the same for both groups. Blood samples were drawn from the heart, and later from the wing vein on days 1, 3, 5, 7,10, 20, 30 and 42. The concentration of total proteins was determined spectrophotometrically using Boehringer Mannheim GmbH optimised kits. The concentration of total proteins in blood plasma in chickens hatched from eggs irradiated with 0.15 Gy on incubation day 7 showed a statistically significant decrease on the sampling day 3 (P less than 0.05) and 7 (P less than 0.01). The concentration of total proteins in blood plasma in chickens hatched from eggs irradiated with 0.15 Gy on incubation day 19 showed a statistically significant increase only on sampling day 1 (P less than 0.05). These results suggest that exposure of eggs to 0.15 Gy of gamma-radiation on the 7th and 19th day of incubation could produce different effects on the protein metabolism in chickens.(author)

Low-dose total skin electron beam therapy for cutaneous lymphoma. Minimal risk of acute toxicities

Energy Technology Data Exchange (ETDEWEB)

Kroeger, Kai; Elsayad, Khaled; Moustakis, Christos; Haverkamp, Uwe; Eich, Hans Theodor [University Hospital of Muenster, Department of Radiation Oncology, Muenster (Germany)

2017-12-15

Low-dose total skin electron beam therapy (TSEBT) is attracting increased interest for the effective palliative treatment of primary cutaneous T-cell lymphoma (pCTCL). In this study, we compared toxicity profiles following various radiation doses. We reviewed the records of 60 patients who underwent TSEBT for pCTCL between 2000 and 2016 at the University Hospital of Munster. The treatment characteristics of the radiotherapy (RT) regimens and adverse events (AEs) were then analyzed and compared. In total, 67 courses of TSEBT were administered to 60 patients. Of these patients, 34 (51%) received a standard dose with a median surface dose of 30 Gy and 33 patients (49%) received a low dose with the median surface dose of 12 Gy (7 salvage low-dose TSEBT courses were administered to 5 patients). After a median follow-up of 15 months, the overall AE rate was 100%, including 38 patients (57%) with grade 2 and 7 (10%) with grade 3 AEs. Patients treated with low-dose TSEBT had significantly fewer grade 2 AEs than those with conventional dose regimens (33 vs. 79%, P < 0.001). A lower grade 3 AE rate was also observed in patients who had received the low-dose regimen compared to those with the conventional dose regimens (6 vs. 15%, P = 0.78). Multiple/salvage low-dose TSEBT courses were not associated with an increased risk of acute AEs. Low-dose TSEBT regimens are associated with significantly fewer grade 2 acute toxicities compared with conventional doses of TSEBT. Repeated/Salvage low-dose TSEBT, however, appears to be tolerable and can even be applied safely in patients with cutaneous relapses. (orig.) [German] Eine niedrigdosierte Ganzhautelektronenbestrahlung (TSEBT) wird vermehrt zur effektiven palliativen Behandlung von Patienten mit primaer kutanen T-Zell-Lymphomen (pCTCL) eingesetzt. In dieser Studie vergleichen wir die Toxizitaetsprofile verschiedener Dosiskonzepte. Untersucht wurden 60 zwischen 2000 und 2016 am Universitaetsklinikum Muenster mittels TSEBT

Total skin electron irradiation: evaluation of dose uniformity throughout the skin surface

International Nuclear Information System (INIS)

Anacak, Yavuz; Arican, Zumre; Bar-Deroma, Raquel; Tamir, Ada; Kuten, Abraham

2003-01-01

In this study, in vivo dosimetic data of 67 total skin electron irradiation (TSEI) treatments were analyzed. Thermoluminescent dosimetry (TLD) measurements were made at 10 different body points for every patient. The results demonstrated that the dose inhomogeneity throughout the skin surface is around 15%. The homogeneity was better at the trunk than at the extratrunk points, and was worse when a degrader was used. There was minimal improvement of homogeneity in subsequent days of treatment

Computed tomography: influence of varying tube current on patient dose and correctness of effective dose calculations; Computertomografie: Einfluss des variablen Roehrenstroms auf die Patientendosis und die Genauigkeit von Berechnungen der effektiven Dosis

Energy Technology Data Exchange (ETDEWEB)

Hietschold, V. [Inst. und Poliklinik fuer Radiologische Diagnostik, Universitaetsklinikum Carl-Gustav-Carus der TU Dresden (Germany); Koch, A.; Laniado, M.; Abolmaali, N.D. [OncoRay, Molecular Imaging, TU Dresden (Germany)

2008-05-15

Purpose: determination of the influence of tube currents varying during a CT scan on organ doses and on the effective dose as a function of patient constitution. Evaluation of the accuracy of effective dose calculations based on summarizing parameters (effective mAs, dose length product [DLP]) compared to calculations based on slice-specific tube currents. Materials and methods: investigation of the CT datasets of 806 patients acquired from the skull base to the proximal thigh with respect to the body mass index (BMI). The effective dose was calculated by means of slice-specific as well as region-specific conversion factors. Results: dose optimization by means of variable tube current resulted in a reduction of the gonad dose in patients with BMI {<=} 20.. 21 kg/m{sup 2} and of the effective dose in patients with BMI {<=} 26 kg/m{sup 2}. Effective dose values calculated with the DLP for 90% of the patients are within an interval of {+-} 20% of the values calculated using slice-specific tube currents. Conclusion: if tube current optimization during the CT scan was applied, for the scan region under investigation, at a BMI already below the German mean value, an increased effective dose was observed. Calculations of the effective dose on the basis of summarizing values such as DLP or effective mAs are of sufficient accuracy. (orig.)

Use of an electron reflector to improve dose uniformity at the vertex during total skin electron therapy

International Nuclear Information System (INIS)

Peters, V.G.

2000-01-01

Purpose: The vertex of the scalp is always tangentially irradiated during total skin electron therapy (TSET). This study was conducted to determine the dose distribution at the vertex for a commonly used irradiation technique and to evaluate the use of an electron reflector, positioned above the head, as a means of improving the dose uniformity. Methods and Materials: Phantoms, simulating the head of a patient, were irradiated using our standard procedure for TSET. The technique is a six-field irradiation using dual angled electron beams at a treatment distance of 3.6 meters. Vertex dosimetry was performed using ionization methods and film. Measurements were made for an unmodified 6 MeV electron beam and for a 4 MeV beam obtained by placing an acrylic scattering plate in the beam line. Studies were performed to examine the effect of electron scattering on vertex dose when a lead reflector, 50 x 50 cm in area, was positioned above the phantom. Results: The surface dose at the vertex, in the absence of the reflector, was found to be less than 40% of the prescribed skin dose. Use of the lead reflector increased this value to 73% for the 6 MeV beam and 99% for the degraded 4 MeV beam. Significant improvements in depth dose were also observed. The dose enhancement is not strongly dependent on reflector distance or angulation since the reflector acts as a large source of broadly scattered electrons. Conclusion: The vertex may be significantly underdosed using standard techniques for total skin electron therapy. Use of an electron reflector improves the dose uniformity at the vertex and may reduce or eliminate the need for supplemental irradiation

Total lymphoid irradiation in the Wistar rat: technique and dosimetry

International Nuclear Information System (INIS)

Hoogenhout, J.; Kazem, I.; de Jong, J.

1983-01-01

The technical and dosimetric aspects of total lymphoid irradiation (TLI) in the Wistar rat were evaluated as part of a set-up to develop a new model for tumor xenotransplantation. Information obtained from anatomical dissections, radionuclide imaging of the spleen, lymphography and chromolymphography was used to standardize the localization portals cut out in a lead plate. The two portals encompassed the lymphoid tissue above and below the diaphragm. A specially designed masonite phantom was used to measure the dose distribution in the simulated target volumes. Ionization chamber dosimetery, thermoluminescence dosimetry and film densitometry were used for measuring exposure and absorbed dose. Irradiation was performed with 250 kV X rays (HVL 3.1 mm Cu). The dose rate was regulated by adjusting the treatment distance. The dose inhomogeneity measured in the target volumes varied between 80-100%. The side scatter dose to non target tissues under the shielded area between the two portals ranged between 20-30%. The technique and dosimetry of total lymphoid irradiation in Wistar rats are now standardized and validated and pave the way for tumor xenotransplantation experiments

In vitro and in vivo effects of low dose HTO contamination modulated by dose rate

International Nuclear Information System (INIS)

Petcu, I.; Savu, D.; Moisoi, N.; Koeteles, G.J.

1997-01-01

The experiment performed in vitro intended to examine whether an adaptive response could be elicited on lymphocytes by low-level contamination of whole blood with tritiated water and if the modification of the dose rate has any influence on it. Lymphocytes pre-exposed to 3 HOH (0.2 - 6.6 MBq/ml) and subsequently irradiated with I Gy γ-rays showed micronuclei frequency significantly lower (40% - 45%) than the expected member (sum of the yields induced by 3 HOH and γ-rays separately). The degree of the radioresistance induced by HTO pre-treatments became higher with decreasing dose-rate for a rather similar total adapting dose. In vivo, the aim of the study was to investigate if different dose rates are inducing modulation of the lipid peroxidation level and of the thymidine uptake in different tissues of animals contaminated by HTO ingestion. The total doses varied between 5 and 20 cGy and were delivered as chronic (100 days) or acute contamination (5 days). It was observed that only doses about 20 cGy caused a dose-rate dependent increase of the lipid peroxidation level in the tissues of small intestine, kidney and spleen. Both chronic and acute contamination did produce reduced incorporation of thymidine in the cells of bone marrow. The most effective decrease of thymidine uptake was induced by the acute contamination in the lower dose domain (approx. 5 cGy). Our hypothesis is that in this dose domain the modification of thymidine uptake could be due to changes at the level of membrane transport. (author)

Radiation dose from food to man after Chernobyl

International Nuclear Information System (INIS)

1988-01-01

The geographical distribution in Norway of radioactive fallout from the Chernobyl accident varied considerably. In order to estimate radioactivity dose levels, two main categories of people were selected for study. The first category covered people who were assumed to have been exposed to much higher doses of radioactivity than the average, i.e. people consuming large amounts of food containing high levels of radioactivity. The other category covered people who were assumed to have received doses of radioactivity close to average. Two procedures were utilized for exposure measurements: Body levels of radioactivity were measured directly, and dietary studies were carried out to estimate the total intake of radioactivity through food as well as the proportion of the total intake which derived from the various foodstuffs. Furthermore, dietary changes and other precautions taken in consequence of the Chernobyl fallout were registered, and assessments were made of the degree to which radioactive cesium intake had been reduced as a result of these changes. The average effective dose equivalent due to the consumption of contaminated food during the first year after the Chernobyl accident was estimated to be in the range 0.12 to 0.25 mSv. A quarter of this dose was due to the consumption of milk. Apart from the Sami reindeer herdsmen in central and southern Norway, the dose which the especially exposed groups had received during the first year was estimated to 0.5 to 1.0 mSv. Almost 90% of the dose derived from the consumption of ''wild'' freshwater fish, reindeer meat and milk. Most of the Sami people received doses varying from 1 to 3 mSv in the first year. By far the greatest contribution (90%) arised from the consumption of reindeer meat

Dose-escalated total body irradiation and autologous stem cell transplantation for refractory hematologic malignancy

International Nuclear Information System (INIS)

McAfee, Steven L.; Powell, Simon N.; Colby, Christine; Spitzer, Thomas R.

2002-01-01

Purpose: To evaluate the feasibility of dose escalation of total body irradiation (TBI) above the previously reported maximally tolerated dose, we have undertaken a Phase I-II trial of dose-escalated TBI with autologous peripheral blood stem cell transplantation (PBSCT) for chemotherapy-refractory lymphoma. Methods and Materials: Nine lymphoma patients with primary refractory disease (PRD) or in resistant relapse (RR) received dose-escalated TBI and PBSCT. The three dose levels of fractionated TBI (200 cGy twice daily) were 1,600 cGy, 1,800 cGy, and 2,000 cGy. Lung blocks were used to reduce the TBI transmission dose by 50%, and the chest wall dose was supplemented to the prescribed dose using electrons. Shielding of the kidneys was performed to keep the maximal renal dose at 1,600 cGy. Three patients, two with non-Hodgkin's lymphoma (NHL) in RR and one with PRD Hodgkin's disease, received 1,600 cGy + PBSCT, three patients (two NHL in RR, one PRD) received 1,800 cGy + PBSCT, and three patients with NHL (two in RR, one PRD) received 2,000 cGy + PBSCT. Results: Toxicities associated with this high-dose TBI regimen included reversible hepatic veno-occlusive disease in 1 patient, Grade 2 mucositis requiring narcotic analgesics in 8 patients, and neurologic toxicities consisting of a symmetrical sensory neuropathy (n=4) and Lhermitte's syndrome (n=1). Interstitial pneumonitis developed in 1 patient who received 1,800 cGy after receiving recombinant α-interferon (with exacerbation after rechallenge with interferon). Six (66%) patients achieved a response. Four (44%) patients achieved complete responses, three of which were of a duration greater than 1 year, and 2 (22%) patients achieved a partial response. One patient remains disease-free more than 5 years posttransplant. Corticosteroid-induced gastritis and postoperative infection resulted in the death of 1 patient in complete response, 429 days posttransplant. Conclusion: TBI in a dose range 1,600-2,000 cGy as

The review of radiation effects of γ total dose in CMOS circuits

International Nuclear Information System (INIS)

Chen Panxun; Gao Wenming; Xie Zeyuan; Mi Bang

1992-01-01

Radiation performances of commercial and rad-hard CMOS circuits are reviewed. Threshold voltage, static power current, V in -V out characteristic and propagation delay time related with total dose are presented for CMOS circuits from several manufacturing processes. The performance of radiation-annealing of experimental circuits had been observed for two years. The comparison has been made between the CMOS circuits made in China and the commercial RCA products. 60 Co γ source can serve as γ simulator of the nuclear explosion

The biological effects of high dose total body irradiation in beagle dogs

International Nuclear Information System (INIS)

Luo Qingliang; Liu Xiaolan; Hao Jing; Xiong Guolin; Dong Bo; Zhao Zhenhu; Xia Zhengbiao; Qiu Liling; Mao Bingzhi

2002-01-01

Objective: To evaluate the biological effects of Beagle dogs irradiated by γ-rays at different doses. Methods: All Beagle dogs were divided into six groups and were subjected respectively to total-body irradiation (TBI) with a single dose of 6.5, 5.5, 5.0, 4.5, 3, 5 and 2.5 Gy γ-rays delivered by 60 Co sources at 7.224 x 10 -2 C/kg per minute. The general condition, blood cell counts and bone marrow cell CFC assays were observed. Results: Vomiting occurred at 0.5 to 2 hours after TBI in all groups. In 6.5 Gy group 3/5 dogs had blood-watery stool and 1/5 in 5.5 Gy group had watery stool. Diarrhea occurred in all other animals. Only one dog in 2.5 Gy group survived, all of others died. in order of decreasing irradiation dosage, the average survival time was 5.0, 8.0, 9.3, 9.5, 10.5 and 14.1 days, respectively. Conclusions: According to the clinical symptoms, leukocyte count and survival time of the dogs, the irradiation dose which will induce very severe hematopoietic radiation syndrome in Beagle dogs is 4.5 to 5.0 Gy

Statistical analysis of dose heterogeneity in circulating blood: Implications for sequential methods of total body irradiation

International Nuclear Information System (INIS)

Molloy, Janelle A.

2010-01-01

Purpose: Improvements in delivery techniques for total body irradiation (TBI) using Tomotherapy and intensity modulated radiation therapy have been proven feasible. Despite the promise of improved dose conformality, the application of these ''sequential'' techniques has been hampered by concerns over dose heterogeneity to circulating blood. The present study was conducted to provide quantitative evidence regarding the potential clinical impact of this heterogeneity. Methods: Blood perfusion was modeled analytically as possessing linear, sinusoidal motion in the craniocaudal dimension. The average perfusion period for human circulation was estimated to be approximately 78 s. Sequential treatment delivery was modeled as a Gaussian-shaped dose cloud with a 10 cm length that traversed a 183 cm patient length at a uniform speed. Total dose to circulating blood voxels was calculated via numerical integration and normalized to 2 Gy per fraction. Dose statistics and equivalent uniform dose (EUD) were calculated for relevant treatment times, radiobiological parameters, blood perfusion rates, and fractionation schemes. The model was then refined to account for random dispersion superimposed onto the underlying periodic blood flow. Finally, a fully stochastic model was developed using binomial and trinomial probability distributions. These models allowed for the analysis of nonlinear sequential treatment modalities and treatment designs that incorporate deliberate organ sparing. Results: The dose received by individual blood voxels exhibited asymmetric behavior that depended on the coherence among the blood velocity, circulation phase, and the spatiotemporal characteristics of the irradiation beam. Heterogeneity increased with the perfusion period and decreased with the treatment time. Notwithstanding, heterogeneity was less than ±10% for perfusion periods less than 150 s. The EUD was compromised for radiosensitive cells, long perfusion periods, and short treatment times

Statistical analysis of dose heterogeneity in circulating blood: implications for sequential methods of total body irradiation.

Science.gov (United States)

Molloy, Janelle A

2010-11-01

Improvements in delivery techniques for total body irradiation (TBI) using Tomotherapy and intensity modulated radiation therapy have been proven feasible. Despite the promise of improved dose conformality, the application of these "sequential" techniques has been hampered by concerns over dose heterogeneity to circulating blood. The present study was conducted to provide quantitative evidence regarding the potential clinical impact of this heterogeneity. Blood perfusion was modeled analytically as possessing linear, sinusoidal motion in the craniocaudal dimension. The average perfusion period for human circulation was estimated to be approximately 78 s. Sequential treatment delivery was modeled as a Gaussian-shaped dose cloud with a 10 cm length that traversed a 183 cm patient length at a uniform speed. Total dose to circulating blood voxels was calculated via numerical integration and normalized to 2 Gy per fraction. Dose statistics and equivalent uniform dose (EUD) were calculated for relevant treatment times, radiobiological parameters, blood perfusion rates, and fractionation schemes. The model was then refined to account for random dispersion superimposed onto the underlying periodic blood flow. Finally, a fully stochastic model was developed using binomial and trinomial probability distributions. These models allowed for the analysis of nonlinear sequential treatment modalities and treatment designs that incorporate deliberate organ sparing. The dose received by individual blood voxels exhibited asymmetric behavior that depended on the coherence among the blood velocity, circulation phase, and the spatiotemporal characteristics of the irradiation beam. Heterogeneity increased with the perfusion period and decreased with the treatment time. Notwithstanding, heterogeneity was less than +/- 10% for perfusion periods less than 150 s. The EUD was compromised for radiosensitive cells, long perfusion periods, and short treatment times. However, the EUD was

Recent Total Ionizing Dose Results and Displacement Damage Results for Candidate Spacecraft Electronics for NASA

Science.gov (United States)

Cochran, Donna J.; Buchner, Stephen P.; Irwin, Tim L.; LaBel, Kenneth A.; Marshall, Cheryl J.; Reed, Robert A.; Sanders, Anthony B.; Hawkins, Donald K.; Flanigan, Ryan J.; Cox, Stephen R.

2005-01-01

We present data on the vulnerability of a variety of candidate spacecraft electronics to total ionizing dose and displacement damage. Devices tested include optoelectronics, digital, analog, linear bipolar devices, hybrid devices, Analog-to- Digital Converters (ADCs), and Digital-to-Analog Converters (DACs), among others. T

Impact of radiation technique, radiation fraction dose, and total cisplatin dose on hearing. Retrospective analysis of 29 medulloblastoma patients

Energy Technology Data Exchange (ETDEWEB)

Scobioala, Sergiu; Kittel, Christopher; Ebrahimi, Fatemeh; Wolters, Heidi; Eich, Hans Theodor [University Hospital of Muenster, Department of Radiotherapy and Radiooncology, Muenster (Germany); Parfitt, Ross; Matulat, Peter; Am Zehnhoff-Dinnesen, Antoinette [University Hospital of Muenster, Department of Phoniatrics and Pediatric Audiology, Muenster (Germany)

2017-11-15

To analyze the incidence and degree of sensorineural hearing loss (SNHL) resulting from different radiation techniques, fractionation dose, mean cochlear radiation dose (D{sub mean}), and total cisplatin dose. In all, 29 children with medulloblastoma (58 ears) with subclinical pretreatment hearing thresholds participated. Radiotherapy (RT) and cisplatin had been applied sequentially according to the HIT MED Guidance. Audiological outcomes up to the latest follow-up (median 2.6 years) were compared. Bilateral high-frequency SNHL was observed in 26 patients (90%). No significant differences were found in mean hearing threshold between left and right ears at any frequency. A significantly better audiological outcome (p < 0.05) was found after tomotherapy at the 6 kHz bone-conduction threshold (BCT) and left-sided 8 kHz air-conduction threshold (ACT) than after a combined radiotherapy technique (CT). Fraction dose was not found to have any impact on the incidence, degree, and time-to-onset of SNHL. Patients treated with CT had a greater risk of SNHL at high frequencies than tomotherapy patients even though D{sub mean} was similar. Increase in severity of SNHL was seen when the total cisplatin dose reached above 210 mg/m{sup 2}, with the highest abnormal level found 8-12 months after RT regardless of radiation technique or fraction dose. The cochlear radiation dose should be kept as low as possible in patients who receive simultaneous cisplatin-based chemotherapy. The risk of clinically relevant HL was shown when D{sub mean} exceeds 45 Gy independent of radiation technique or radiation regime. Cisplatin ototoxicity was shown to have a dose-dependent effect on bilateral SNHL, which was more pronounced in higher frequencies. (orig.) [German] Analyse von Inzidenz und Schweregrad einer sensorineuralen Schwerhoerigkeit (''sensorineural hearing loss'', SNHL) infolge der Wirkung unterschiedlicher Bestrahlungstechniken, Fraktionierungen, mittlerer

Influence of radioprotectors on total body weight evolution and on oxygen consumption in lethal dose irradiated animals. (Preliminary study)

International Nuclear Information System (INIS)

Fatome, M.; Martine, G.; Bargy, E.; Andrieu, L.

Comparison of total body weight evolution and oxygen consumption in lethal dose irradiated animals, protected by various well known radioprotective substances, isolated or in mixture, with evolution and consumption of non protected animals irradiated at the same dose and with these of check animals [fr

Northern Marshall Islands radiological survey: terrestrial food chain and total doses

International Nuclear Information System (INIS)

Robison, W.L.; Mount, M.E.; Phillips, W.A.; Conrado, C.A.; Stuart, M.L.; Stoker, C.E.

1982-01-01

A radiological survey was conducted from September through November of 1978 to assess the concentrations of persistent manmade radionuclides in the terrestrial and marine environments of 11 atolls and 2 islands in the Northern Marshall Islands. The survey consisted mainly of an aerial radiological reconnaissance to map the external gamma-ray exposure rates over the islands of each atoll. The logistical support for the entire survey was designed to accommodate this operation. As a secondary phase of the survey, shore parties collected appropriate terrestrial and marine samples to assess the radiological dose from pertinent food chains to those individuals residing on the atolls, who may in the future reside on some of the presently uninhabited atolls, or who collect food from these atolls. Over 5000 terrestrial and marine samples were collected for radionuclide analysis from 76 different islands. Soils, vegetation, indigenous animals, and cistern water and groundwater were collected from the islands. Reef and pelagic fish, clams, lagoon water, and sediments were obtained from the lagoons. The concentration data for 90 Sr, 137 Cs, 238 Pu, 239 240 Pu, and 241 Am in terrestrial food crops, fowl, and animals collected at the atolls or islands are summarized. An assessment of the total dose from the major exposure pathways including external gamma, terrestrial food chain including food products and drinking water, marine food chain, and inhalation is provided. Radiological doses at each atoll or island are calculated from the average radionuclide concentrations in the terrestrial foods, marine foods, etc. assuming the average daily intake for each food item

Total body irradiation: current indications; L`irradiation corporelle totale: les indications actuelles

Energy Technology Data Exchange (ETDEWEB)

Giraud, P.; Danhier, S.; Dubray, B.; Cosset, J.M. [Institut Curie, 75 - Paris (France)

1998-05-01

The choice of dose and fractionation for total body irradiation is made difficult by the large number of considerations to be taken into account. The outcome of bone marrow transplantation after total body irradiation can be understood in terms of tumor cell killing, engraftment, and normal tissue damage, each of these endpoints being influenced by irradiation-, disease-, transplant-, and patient- related factors. Interpretation of clinical data is further hampered by the overwhelming influence of logistic constraints, the small numbers of randomized studies, and the concomitant variations in total dose and fraction size or dose rate. So far, three cautious conclusions can be drawn in order to tentatively adapt the total body irradiation schedule to clinically-relevant situations. Firstly, the organs at risk for normal tissue damage (lung, liver, lens, kidney) are protected by delivering small doses per fraction at low dose rate. This suggests that, when toxicity is at stake (e.g. in children), fractionated irradiation should be preferred, provided that inter-fraction intervals are long enough. Secondly, fractionated irradiation should be avoided in case of T-cell depleted transplant, given the high risk of graft rejection in this setting. An alternative would be to increase total (or fractional) dose of fractionated total body irradiation, but this approach is likely to induce more normal tissue toxicity. Thirdly, clinical data have shown higher relapse rates in chronic myeloid leukemia after fractionated or low dose rate total body irradiation, suggesting that fractionated irradiation should not be recommended, unless total (or fractional) dose is increased. Total body irradiation-containing regimens, primarily cyclophosphamide / total body irradiation, are either equivalent to or better than the chemotherapy-only regimens, primarily busulfan / cyclophosphamide. Busulfan / cyclophosphamide certainly represents a reasonable alternative, especially in patients who

Measurement with total scatter calibrate factor at different depths in the calculation of prescription dose

International Nuclear Information System (INIS)

Li Lijun; Zhu Haijun; Zhang Xinzhong; Li Feizhou; Song Hongyu

2004-01-01

Objective: To evaluate the method of measurement of total scatter calibrate factor (Sc, p). Methods: To measure the Sc, p at different depths on central axis of 6MV, 15MV photon beams through different ways. Results: It was found that the measured data of Sc, p changed with the different depths to a range of 1% - 7%. Using the direct method, the Sc, p measured depth should be the same as the depth in dose normalization point of the prescription dose. If the Sc, p (fsz, d) was measured at the other depths, it could be obtained indirectly by the calculation formula. Conclusions: The Sc, p in the prescription dose can be obtained either by the direct measure method or the indirect calculation formula. But emphasis should be laid on the proper measure depth. (authors)

Total Ionizing Dose Effects on Threshold Switching in 1T-Tantalum Disulfide Charge-Density-Wave Devices

OpenAIRE

Liu, G.; Zhang, E. X.; Liang, C. D.; Bloodgood, M. A.; Salguero, T. T.; Fleetwood, D. M.; Balandin, A. A.

2017-01-01

The 1T polytype of TaS2 exhibits voltage-triggered threshold switching as a result of a phase transition from nearly commensurate to incommensurate charge density wave states. Threshold switching, persistent above room temperature, can be utilized in a variety of electronic devices, e.g., voltage controlled oscillators. We evaluated the total-ionizing-dose response of thin film 1T-TaS2 at doses up to 1 Mrad(SiO2). The threshold voltage changed by less than 2% after irradiation, with persisten...

Total-dose radiation effects data for semiconductor devices. 1985 supplement. Volume 2, part A

International Nuclear Information System (INIS)

Martin, K.E.; Gauthier, M.K.; Coss, J.R.; Dantas, A.R.V.; Price, W.E.

1986-05-01

Steady-state, total-dose radiation test data, are provided in graphic format for use by electronic designers and other personnel using semiconductor devices in a radiation environment. The data were generated by JPL for various NASA space programs. This volume provides data on integrated circuits. The data are presented in graphic, tabular, and/or narrative format, depending on the complexity of the integrated circuit. Most tests were done using the JPL or Boeing electron accelerator (Dynamitron) which provides a steady-state 2.5 MeV electron beam. However, some radiation exposures were made with a cobalt-60 gamma ray source, the results of which should be regarded as only an approximate measure of the radiation damage that would be incurred by an equivalent electron dose

Total-ionizing-dose effects on isolation oxides in modern CMOS technologies

International Nuclear Information System (INIS)

Barnaby, Hugh J.; Mclain, Michael; Esqueda, Ivan Sanchez

2007-01-01

This paper presents experimental data on the total dose response of deep sub-micron bulk CMOS devices and integrated circuits. Ionizing radiation experiments on shallow trench isolation (STI) field oxide MOS capacitors (FOXCAP) indicate a characteristic build-up of radiation-induced defects in the dielectric. In this paper, capacitors fabricated with STI, thermal, SIMOX and bipolar base oxides of similar thickness are compared and show the STI oxide to be most susceptible to radiation effects. Experimental data on irradiated shift registers and n-channel MOSFETs are also presented. These data indicate that radiation damage to the STI can increase the off-state current of n-channel devices and the standby current of CMOS integrated circuits

Compendium of Current Total Ionizing Dose and Displacement Damage Results from NASA Goddard Space Flight Center and NASA Electronic Parts and Packaging Program

Science.gov (United States)

Topper, Alyson D.; Campola, Michael J.; Chen, Dakai; Casey, Megan C.; Yau, Ka-Yen; Cochran, Donna J.; Label, Kenneth A.; Ladbury, Raymond L.; Mondy, Timothy K.; O'Bryan, Martha V.;

Total Dose Effects on Bipolar Integrated Circuits at Low Temperature

Science.gov (United States)

Johnston, A. H.; Swimm, R. T.; Thorbourn, D. O.

2012-01-01

Total dose damage in bipolar integrated circuits is investigated at low temperature, along with the temperature dependence of the electrical parameters of internal transistors. Bandgap narrowing causes the gain of npn transistors to decrease far more at low temperature compared to pnp transistors, due to the large difference in emitter doping concentration. When irradiations are done at temperatures of -140 deg C, no damage occurs until devices are warmed to temperatures above -50 deg C. After warm-up, subsequent cooling shows that damage is then present at low temperature. This can be explained by the very strong temperature dependence of dispersive transport in the continuous-time-random-walk model for hole transport. For linear integrated circuits, low temperature operation is affected by the strong temperature dependence of npn transistors along with the higher sensitivity of lateral and substrate pnp transistors to radiation damage.

Biologically effective dose in total-body irradiation and hematopoietic stem cell transplantation

International Nuclear Information System (INIS)

Kal, H.B.; Kempen-Harteveld, M.L. van; Heijenbrok-Kal, M.H.; Struikmans, H.

2006-01-01

Background and Purpose: Total-body irradiation (TBI) is an important part of the conditioning regimen for hematopoietic stem cell transplantation (HSCT) in patients with hematologic malignancies. The results after treatment with various TBI regimes were compared, and dose-effect relationships for the endpoints relapse incidence, disease-free survival, treatment-related mortality, and overall survival were derived. The aim was to define requirements for an optimal treatment schedule with respect to leukemic cell kill and late normal-tissue morbidity. Material and Methods: A literature search was performed. Three randomized studies, four studies comparing results of two or three TBI regimens, and nine reports with results of one specific TBI regimen were identified. Biologically effective doses (BEDs) were calculated. The results of the randomized studies and the studies comparing results of two or three TBI regimens were pooled, and the pooled relative risk (RR) was calculated for the treatments with high BED values versus treatments with a low BED. BED-effect relationships were obtained. Results: RRs for the high BED treatments were significantly lower for relapse incidence, not significantly different for disease-free survival and treatment-related mortality, and significantly higher for overall survival. BED-effect relationships indicate a decrease in relapse incidence and treatment-related mortality and an increase in disease-free and overall survival with higher BED values. Conclusion: 'More dose is better', provided that a TBI setting is used limiting the BEDs of lungs, kidneys, and eye lenses. (orig.)

Variability of dose predictions for cesium-137 and radium-226 using the PRISM method

International Nuclear Information System (INIS)

Bergstroem, U.; Andersson, K.; Roejder, B.

1984-01-01

The uncertainty associated with dose predictions for cesium-137 and radium-226 in a specific ecosystem has been studied. The method used is a systematic method for determining the effect of parameter uncertainties on model prediction called PRISM. The ecosystems studied are different types of lakes where the following transport processes are included: runoff of water in the lake, irrigation, transport in soil, in groundwater and in sediment. The ecosystems are modelled by the compartment principle, using the BIOPATH-code. Seven different internal exposure pathways are included. The total dose commitment for both nuclides varies about two orders of magnitude. For cesium-137 the total dose and the uncertainty are dominated by the consumption of fish. The most important factor to the total uncertainty is the concentration factor water-fish. For radium-226 the largest contributions to the total dose are the exposure pathways, fish, milk and drinking-water. Half of the uncertainty lies in the milk dose. This uncertainty is dominated by the distribution factor for milk. (orig.)

Response of cellulose nitrate track detectors to electron doses

CERN Document Server

Segovia, N; Moreno, A; Vazquez-Polo, G; Santamaría, T; Aranda, P; Hernández, A

1999-01-01

In order to study alternative dose determination methods, the bulk etching velocity and the latent track annealing of LR 115 track detectors was studied during electron irradiation runs from a Pelletron accelerator. For this purpose alpha irradiated and blank detectors were exposed to increasing electron doses from 10.5 to 317.5 kGy. After the irradiation with electrons the detectors were etched under routine conditions, except for the etching time, that was varied for each electron dose in order to reach a fixed residual thickness. The variation of the bulk etching velocity as a function of each one of the electron doses supplied, was interpolated in order to obtain dosimetric response curves. The observed annealing effect on the latent tracks is discussed as a function of the total electron doses supplied and the temperature.

In vivo dosimetry with semiconducting diodes for dose verification in total-body irradiation. A 10-year experience

International Nuclear Information System (INIS)

Ramm, U.; Licher, J.; Moog, J.; Scherf, C.; Kara, E.; Boettcher, H.D.; Roedel, C.; Mose, S.

2008-01-01

Background and purpose: for total-body irradiation (TBI) using the translation method, dose distribution cannot be computed with computer-assisted three-dimensional planning systems. Therefore, dose distribution has to be primarily estimated based on CT scans (beam-zone method) which is followed by in vivo measurements to ascertain a homogeneous dose delivery. The aim of this study was to clinically establish semiconductor probes as a simple and fast method to obtain an online verification of the dose at relevant points. Patients and methods: in 110 consecutively irradiated TBI patients (12.6 Gy, 2 x 1.8 Gy/day), six semiconductor probes were attached to the body surface at dose-relevant points (eye/head, neck, lung, navel). The mid-body point of the abdomen was defined as dose reference point. The speed of translation was optimized to definitively reach the prescribed dose in this point. Based on the entrance and exit doses, the mid-body doses at the other points were computed. The dose homogeneity in the entire target volume was determined comparing all measured data with the dose at the reference point. Results: after calibration of the semiconductor probes under treatment conditions the dose in selected points and the dose homogeneity in the target volume could be quantitatively specified. In the TBI patients, conformity of calculated and measured doses in the given points was achieved with small deviations of adequate accuracy. The data of 80% of the patients are within an uncertainty of ± 5%. Conclusion: during TBI using the translation method, dose distribution and dose homogeneity can be easily controlled in selected points by means of semiconductor probes. Semiconductor probes are recommended for further use in the physical evaluation of TBI. (orig.)

In pediatric leukemia, dose evaluation according to the type of compensators in total body irradiation

Energy Technology Data Exchange (ETDEWEB)

Lee, Dong Yeon [Dongnam Inst. of Radiological and Medical science, Busan (Korea, Republic of); Kim, Chang Soo; Kim, Jung Hoon [Dept. of Radiological Science, College of Health Science, Catholic University of Busan, Busan (Korea, Republic of)

2015-04-15

Total body irradiation (TBI) and chemotherapy are the pre-treatment method of a stem cell transplantations of the childhood leukemia. in this study, we evaluate the Quantitative human body dose prior to the treatment. The MCNPX simulation program evaluated by changing the material of the tissue compensators with imitation material of pediatric exposure in a virtual space. As a result, first, the average skin dose with the material of the tissue compensators of Plexiglass tissue compensators is 74.60 mGy/min, Al is 73.96 mGy/min, Cu is 72.26 mGy/min and Pb 67.90 mGy/min respectively. Second, regardless of the tissue compensators material that organ dose were thyroid, gentile, digestive system, brain, lungs, kidneys higher in order. Finally, the ideal distance between body compensator and the patient were 50 cm aparting each other. In conclusion, tissue compensators Al, Cu, Pb are able to replace of the currently used in Plexiglass materials.

High Total Ionizing Dose and Temperature Effects on Micro- and Nano-electronic Devices

International Nuclear Information System (INIS)

Gaillardin, M.; Martinez, M.; Paillet, P.; Leray, J.L.; Marcandella, C.; Duhamel, O.; Raine, M.; Richard, N.; Girard, S.; Ouerdane, Y.; Boukenter, A.; Goiffon, V.; Magnan, P.; Andrieu, F.; Barraud, S.; Faynot, O.

2013-06-01

This paper investigates the vulnerability of several micro- and nano-electronic technologies to a mixed harsh environment including high total ionizing dose at MGy levels and high temperature. Such operating conditions have been revealed recently for several applications like new security systems in existing or future nuclear power plants, fusion experiments, or deep space missions. In this work, the competing effects already reported in literature of ionizing radiations and temperature are characterized in elementary devices made of MOS transistors from several technologies. First, devices are irradiated using a radiation laboratory X-ray source up to MGy dose levels at room temperature. Devices are grounded during irradiation to simulate a circuit which waits for a wake up signal, representing most of the lifetime of an integrated circuit operating in a harsh environment. Devices are then annealed at several temperatures to discuss the post-irradiation behavior and to determine whether an elevated temperature is an issue or not for circuit function in mixed harsh environments. (authors)

Dose-effect relationship for cataract induction after single-dose total body irradiation and bone marrow transplantation for acute leukemia

International Nuclear Information System (INIS)

Kempen-Harteveld, M. Loes van; Belkacemi, Yazid; Kal, Henk B.; Labopin, Myriam; Frassoni, Francesco

2002-01-01

Purpose: To determine a dose-effect relationship for cataract induction, the tissue-specific parameter, α/β, and the rate of repair of sublethal damage, μ value, in the linear-quadratic formula have to be known. To obtain these parameters for the human eye lens, a large series of patients treated with different doses and dose rates is required. The data of patients with acute leukemia treated with single-dose total body irradiation (STBI) and bone marrow transplantation (BMT) collected by the European Group for Blood and Marrow Transplantation were analyzed. Methods and Materials: The data of 495 patients who underwent BMT for acute leukemia, who had STBI as part of their conditioning regimen, were analyzed using the linear-quadratic concept. The end point was the incidence of cataract formation after BMT. Of the analyzed patients, 175 were registered as having cataracts. Biologic effective doses (BEDs) for different sets of values for α/β and μ were calculated for each patient. With Cox regression analysis, using the overall chi-square test as the parameter evaluating the goodness of fit, α/β and μ values were found. Risk factors for cataract induction were the BED of the applied TBI regimen, allogeneic BMT, steroid therapy for >14 weeks, and heparin administration. To avoid the influence of steroid therapy and heparin on cataract induction, patients who received steroid or heparin treatment were excluded, leaving only the BED as a risk factor. Next, the most likely set of α/β and μ values was obtained. With this set, the cataract-free survival rates were calculated for specific BED intervals, according to the Kaplan-Meier method. From these calculations, cataract incidences were obtained as function of the BED at 120 months after STBI. Results: The use of BED instead of the TBI dose enabled the incidence of cataract formation to be predicted in a reasonably consistent way. With Cox regression analysis for all STBI data, a maximal chi-square value was

Metabolites Identified during Varied Doses of Aspergillus Species in Zea mays Grains, and Their Correlation with Aflatoxin Levels

Directory of Open Access Journals (Sweden)

Titilayo D. O. Falade

2018-05-01

Full Text Available Aflatoxin contamination is associated with the development of aflatoxigenic fungi such as Aspergillus flavus and A. parasiticus on food grains. This study was aimed at investigating metabolites produced during fungal development on maize and their correlation with aflatoxin levels. Maize cobs were harvested at R3 (milk, R4 (dough, and R5 (dent stages of maturity. Individual kernels were inoculated in petri dishes with four doses of fungal spores. Fungal colonisation, metabolite profile, and aflatoxin levels were examined. Grain colonisation decreased with kernel maturity: milk-, dough-, and dent-stage kernels by approximately 100%, 60%, and 30% respectively. Aflatoxin levels increased with dose at dough and dent stages. Polar metabolites including alanine, proline, serine, valine, inositol, iso-leucine, sucrose, fructose, trehalose, turanose, mannitol, glycerol, arabitol, inositol, myo-inositol, and some intermediates of the tricarboxylic acid cycle (TCA—also known as citric acid or Krebs cycle were important for dose classification. Important non-polar metabolites included arachidic, palmitic, stearic, 3,4-xylylic, and margaric acids. Aflatoxin levels correlated with levels of several polar metabolites. The strongest positive and negative correlations were with arabitol (R = 0.48 and turanose and (R = −0.53, respectively. Several metabolites were interconnected with the TCA; interconnections of the metabolites with the TCA cycle varied depending upon the grain maturity.

Gonadal radiation dose and its genetic significance in radioiodine therapy of hyperthyroidism

International Nuclear Information System (INIS)

Robertson, J.S.; Gorman, C.A.

1976-01-01

Published estimates of radiation dose to the gonads from 131 I therapy of Graves' disease vary widely, largely because of differences in assumptions regarding the details of iodine kinetics. The calculations described in this paper show that hyperthyroid patients treated with 10 mCi of 131 I will usually receive a total radiation dose to the ovaries or testes of less than 3 rad. Several common roentgenographic diagnostic procedures may involve a greater radiation dose and a greater genetic hazard than does the usual 131 I treatment for hyperthyroidism. It is important to minimize total exposure to radiation, but it seems unreasonable to deny 131 I treatment for hyperthyroidism to young men and nonpregnant young women on the grounds of genetic hazard alone

Compendium of Single Event Effects, Total Ionizing Dose, and Displacement Damage for Candidate Spacecraft Electronics for NASA

Science.gov (United States)

LaBel, Kenneth A.; OBryan, Martha V.; Chen, Dakai; Campola, Michael J.; Casey, Megan C.; Pellish, Jonathan A.; Lauenstein, Jean-Marie; Wilcox, Edward P.; Topper, Alyson D.; Ladbury, Raymond L.;

Central axis dose verification in patients treated with total body irradiation of photons using a Computed Radiography system

International Nuclear Information System (INIS)

Rubio Rivero, A.; Caballero Pinelo, R.; Gonzalez Perez, Y.

2015-01-01

To propose and evaluate a method for the central axis dose verification in patients treated with total body irradiation (TBI) of photons using images obtained through a Computed Radiography (CR) system. It was used the Computed Radiography (Fuji) portal imaging cassette readings and correlate with measured of absorbed dose in water using 10 x 10 irradiation fields with ionization chamber in the 60 Co equipment. The analytical and graphic expression is obtained through software 'Origin8', the TBI patient portal verification images were processed using software ImageJ, to obtain the patient dose. To validate the results, the absorbed dose in RW3 models was measured with ionization chamber with different thickness, simulating TBI real conditions. Finally it was performed a retrospective study over the last 4 years obtaining the patients absorbed dose based on the reading in the image and comparing with the planned dose. The analytical equation obtained permits estimate the absorbed dose using image pixel value and the dose measured with ionization chamber and correlated with patient clinical records. Those results are compared with reported evidence obtaining a difference less than 02%, the 3 methods were compared and the results are within 10%. (Author)

The feasibility of 10 keV X-ray as radiation source in total dose response radiation test

International Nuclear Information System (INIS)

Li Ruoyu; Li Bin; Luo Hongwei; Shi Qian

2005-01-01

The standard radiation source utilized in traditional total dose response radiation test is 60 Co, which is environment-threatening. X-rays, as a new radiation source, has the advantages such as safety, precise control of dose rate, strong intensity, possibility of wafer-level test or even on-line test, which greatly reduce cost for package, test and transportation. This paper discussed the feasibility of X-rays replacing 60 Co as the radiation source, based on the radiation mechanism and the effects of radiation on gate oxide. (authors)

Comparative study of eye dose and chest dose received during radiopharmaceutical production processes

International Nuclear Information System (INIS)

Chindarkar, A.S.; Chavan, S.V.; Sawant, D.K.; Sahoo, L.; Gopalakrishnan, R.K.; Sneha, C.; Sachdev, S.S.; Dey, A.C.

2018-01-01

Radiopharmaceutical laboratory, BRIT, Vashi produces different radiopharmaceuticals of 131 I, 153 Sm, 99 Mo/ 99m Tc and 177 Lu. Principle gamma energies of these isotopes vary from 103 to 740 KeV and their maximum beta energies vary from 384 to 1214 KeV. In the light of the revised eye lens dose limit recommended in IAEA Basic Safety Standard Interim Edition No. GSR Part 3 (IAEA-2011), the study of radiation dose for eye lens was carried out using CaSO 4 : Dy based Thermo luminescence dosimeter (TLD). This TLD was worn at center of the forehead to measure eye lens dose. This TLD dose was then compared with chest TLD dose to deduce any correlation between these TLD doses. These TLD doses were assessed on quarterly basis. Eight quarter data of these TLD doses were compared

Thoron in the air: assessment of the occupational dose

International Nuclear Information System (INIS)

Campos, Marcia Pires de

1999-01-01

The occupational dose due to inhalation of thoron was assessed through the committed effective dose and the committed equivalent dose received by workers exposed to the radionuclide at the nuclear materials storage site and the thorium purification plant of the Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN/SP). The radiation doses were performed by compartmental analysis following the compartmental model of the lung and biokinetic model of the lead, through the thoron equilibrium equivalent concentrations. These values were obtained by gamma ray spectrometry, total alpha count and alpha particle spectrometry of air samples glass fiber filters. The results of the thoron equilibrium equivalent concentration varied from 0.3 to 0,67 Bq/m 3 at the nuclear materials storage site and from 0.9 to 249.8 Bq/m 3 at the thorium purification plant. The committed effective dose due to thoron inhalation varied from 0.03 mSv/a to 0.67 mSv/a at the nuclear materials storage site and from 0.12 mSv/a to 6.0 mSv/a at the thorium purification plant. The risk assessment of lung cancer and fatal cancers for the workers exposed to thoron at the nuclear materials storage site and the thorium purification plant showed an increment for both risk cancer. (author)

Biological effective dose studies in carcinoma of uterine cervix

International Nuclear Information System (INIS)

Yadav, Poonam; Ramasubramanian, V.

2008-01-01

Cancer of cervix is the second most common cancer worldwide among women. Several treatments related protocols of radiotherapy have been followed over few decades in its treatment for evaluating the response. These physical doses varying on the basics of fractionation size, dose rate and total dose needed to be indicated as biological effective dose (BED) to rationalize these treatments. The curative potential of radiation therapy in the management of carcinoma of the cervix is greatly enhanced by the use of intracavitary brachytherapy. Successful brachytherapy requires the high radiation dose to be delivered to the tumor where as minimum radiation dose reach to surrounding normal tissue. Present study is aimed to evaluate biologically effective dose in patients receiving high dose-rate brachytherapy plus external beam radiotherapy based on tumor cell proliferation values in cancer of the cervix patients. The study includes 30 patients' data as a retrospective analysis. In addition determine extent of a dose-response relationship existing between the biological effective dose at Point A and the bladder and rectum and the clinical outcomes

Four-Dimensional Patient Dose Reconstruction for Scanned Ion Beam Therapy of Moving Liver Tumors

International Nuclear Information System (INIS)

Richter, Daniel; Saito, Nami; Chaudhri, Naved; Härtig, Martin; Ellerbrock, Malte; Jäkel, Oliver; Combs, Stephanie E.; Habermehl, Daniel; Herfarth, Klaus; Durante, Marco; Bert, Christoph

2014-01-01

Purpose: Estimation of the actual delivered 4-dimensional (4D) dose in treatments of patients with mobile hepatocellular cancer with scanned carbon ion beam therapy. Methods and Materials: Six patients were treated with 4 fractions to a total relative biological effectiveness (RBE)–weighted dose of 40 Gy (RBE) using a single field. Respiratory motion was addressed by dedicated margins and abdominal compression (5 patients) or gating (1 patient). 4D treatment dose reconstructions based on the treatment records and the measured motion monitoring data were performed for the single-fraction dose and a total of 17 fractions. To assess the impact of uncertainties in the temporal correlation between motion trajectory and beam delivery sequence, 3 dose distributions for varying temporal correlation were calculated per fraction. For 3 patients, the total treatment dose was formed from the fractional distributions using all possible combinations. Clinical target volume (CTV) coverage was analyzed using the volumes receiving at least 95% (V 95 ) and 107% (V 107 ) of the planned doses. Results: 4D dose reconstruction based on daily measured data is possible in a clinical setting. V 95 and V 107 values for the single fractions ranged between 72% and 100%, and 0% and 32%, respectively. The estimated total treatment dose to the CTV exhibited improved and more robust dose coverage (mean V 95 > 87%, SD < 3%) and overdose (mean V 107 < 4%, SD < 3%) with respect to the single-fraction dose for all analyzed patients. Conclusions: A considerable impact of interplay effects on the single-fraction CTV dose was found for most of the analyzed patients. However, due to the fractionated treatment, dose heterogeneities were substantially reduced for the total treatment dose. 4D treatment dose reconstruction for scanned ion beam therapy is technically feasible and may evolve into a valuable tool for dose assessment

A real time dose monitoring and dose reconstruction tool for patient specific VMAT QA and delivery

International Nuclear Information System (INIS)

Tyagi, Neelam; Yang Kai; Gersten, David; Yan Di

2012-01-01

Purpose: To develop a real time dose monitoring and dose reconstruction tool to identify and quantify sources of errors during patient specific volumetric modulated arc therapy (VMAT) delivery and quality assurance. Methods: The authors develop a VMAT delivery monitor tool called linac data monitor that connects to the linac in clinical mode and records, displays, and compares real time machine parameters with the planned parameters. A new measure, called integral error, keeps a running total of leaf overshoot and undershoot errors in each leaf pair, multiplied by leaf width, and the amount of time during which the error exists in monitor unit delivery. Another tool reconstructs Pinnacle 3 ™ format delivered plan based on the saved machine logfile and recalculates actual delivered dose in patient anatomy. Delivery characteristics of various standard fractionation and stereotactic body radiation therapy (SBRT) VMAT plans delivered on Elekta Axesse and Synergy linacs were quantified. Results: The MLC and gantry errors for all the treatment sites were 0.00 ± 0.59 mm and 0.05 ± 0.31°, indicating a good MLC gain calibration. Standard fractionation plans had a larger gantry error than SBRT plans due to frequent dose rate changes. On average, the MLC errors were negligible but larger errors of up to 6 mm and 2.5° were seen when dose rate varied frequently. Large gantry errors occurred during the acceleration and deceleration process, and correlated well with MLC errors (r= 0.858, p= 0.0004). PTV mean, minimum, and maximum dose discrepancies were 0.87 ± 0.21%, 0.99 ± 0.59%, and 1.18 ± 0.52%, respectively. The organs at risk (OAR) doses were within 2.5%, except some OARs that showed up to 5.6% discrepancy in maximum dose. Real time displayed normalized total positive integral error (normalized to the total monitor units) correlated linearly with MLC (r= 0.9279, p < 0.001) and gantry errors (r= 0.742, p= 0.005). There is a strong correlation between total integral

Origins of Total-Dose Response Variability in Linear Bipolar Microcircuits

International Nuclear Information System (INIS)

Barnaby, H.J.; Cirba, C.R.; Schrimpf, R.D.; Fleetwood, D.M.; Pease, R.L.; Shaneyfelt, Marty R.; Turflinger, T.; Krieg, J.F.; Maher, M.C.

2000-01-01

LM1ll voltage comparators exhibit a wide range of total-dose-induced degradation. Simulations show this variability may be a natural consequence of the low base doping of the substrate PNP (SPNP) input transistors. Low base doping increases the SPNP's collector to base breakdown voltage, current gain, and sensitivity to small fluctuations in the radiation-induced oxide defect densities. The build-up of oxide trapped charge (N ot ) and interface traps (N it ) is shown to be a function of pre-irradiation bakes. Experimental data indicate that, despite its structural similarities to the LM111, irradiated input transistors of the LM124 operational amplifier do not exhibit the same sensitivity to variations in pre-irradiation thermal cycles. Further disparities in LM111 and LM124 responses may result from a difference in the oxide defect build-up in the two part types. Variations in processing, packaging, and circuit effects are suggested as potential explanations

Low-dose (10-Gy) total skin electron beam therapy for cutaneous T-cell lymphoma

DEFF Research Database (Denmark)

Kamstrup, Maria R; Gniadecki, Robert; Iversen, Lars

2015-01-01

a total dose of 10 Gy in 10 fractions. Data from 10 of these patients were published previously but were included in the current pooled data analysis. Outcome measures were response rate, duration of response, and toxicity. RESULTS: The overall response rate was 95% with a complete cutaneous response......PURPOSE: Cutaneous T-cell lymphomas (CTCLs) are dominated by mycosis fungoides (MF) and Sézary syndrome (SS), and durable disease control is a therapeutic challenge. Standard total skin electron beam therapy (TSEBT) is an effective skin-directed therapy, but the possibility of retreatments...... or a very good partial response rate (response was 174 days (5.8 months; range: 60-675 days). TSEBT-related acute adverse events (grade 1 or 2) were observed in 60% of patients. CONCLUSIONS...

Image-guided total marrow and total lymphatic irradiation using helical tomotherapy

International Nuclear Information System (INIS)

Schultheiss, Timothy E.; Wong, Jeffrey; Liu, An; Olivera, Gustavo; Somlo, George

2007-01-01

Purpose: To develop a treatment technique to spare normal tissue and allow dose escalation in total body irradiation (TBI). We have developed intensity-modulated radiotherapy techniques for the total marrow irradiation (TMI), total lymphatic irradiation, or total bone marrow plus lymphatic irradiation using helical tomotherapy. Methods and Materials: For TBI, we typically use 12 Gy in 10 fractions delivered at an extended source-to-surface distance (SSD). Using helical tomotherapy, it is possible to deliver equally effective doses to the bone marrow and lymphatics while sparing normal organs to a significant degree. In the TMI patients, whole body skeletal bone, including the ribs and sternum, comprise the treatment target. In the total lymphatic irradiation, the target is expanded to include the spleen and major lymph node areas. Sanctuary sites for disease (brain and testes) are included when clinically indicated. Spared organs include the lungs, esophagus, parotid glands, eyes, oral cavity, liver, kidneys, stomach, small and large intestine, bladder, and ovaries. Results: With TBI, all normal organs received the TBI dose; with TMI, total lymphatic irradiation, and total bone marrow plus lymphatic irradiation, the visceral organs are spared. For the first 6 patients treated with TMI, the median dose to organs at risk averaged 51% lower than would be achieved with TBI. By putting greater weight on the avoidance of specific organs, greater sparing was possible. Conclusion: Sparing of normal tissues and dose escalation is possible using helical tomotherapy. Late effects such as radiation pneumonitis, veno-occlusive disease, cataracts, neurocognitive effects, and the development of second tumors should be diminished in severity and frequency according to the dose reduction realized for the organs at risk

Evaluation of Total Daily Dose and Glycemic Control for Patients on U-500 Insulin Admitted to the Hospital

Science.gov (United States)

2016-05-20

regular insulin has significantly increased in recent years. These patients are severely insulin resistant requiring high doses of insulin to achieve...on U-500 Insulin Admitted to the Hospital presented at SURF Conference, San Antonio, TX 20 May 201 6 with MDWI 41-108, and has been assigned local...59th CSPG/SGVU) C.201 4 . I 52d PROTOCOL TITLE Evaluation of Total Dai ly Dose and Glycemic Control for Patients on U-500 Insulin Admitted to the

Low Dose Gamma Irradiation Does Not Affect the Quality or Total Ascorbic Acid Concentration of "Sweetheart" Passionfruit (Passiflora edulis).

Science.gov (United States)

Golding, John B; Blades, Barbara L; Satyan, Shashirekha; Spohr, Lorraine J; Harris, Anne; Jessup, Andrew J; Archer, John R; Davies, Justin B; Banos, Connie

2015-08-26

Passionfruit ( Passiflora edulis , Sims, cultivar "Sweetheart") were subject to gamma irradiation at levels suitable for phytosanitary purposes (0, 150, 400 and 1000 Gy) then stored at 8 °C and assessed for fruit quality and total ascorbic acid concentration after one and fourteen days. Irradiation at any dose (≤1000 Gy) did not affect passionfruit quality (overall fruit quality, colour, firmness, fruit shrivel, stem condition, weight loss, total soluble solids level (TSS), titratable acidity (TA) level, TSS/TA ratio, juice pH and rot development), nor the total ascorbic acid concentration. The length of time in storage affected some fruit quality parameters and total ascorbic acid concentration, with longer storage periods resulting in lower quality fruit and lower total ascorbic acid concentration, irrespective of irradiation. There was no interaction between irradiation treatment and storage time, indicating that irradiation did not influence the effect of storage on passionfruit quality. The results showed that the application of 150, 400 and 1000 Gy gamma irradiation to "Sweetheart" purple passionfruit did not produce any deleterious effects on fruit quality or total ascorbic acid concentration during cold storage, thus supporting the use of low dose irradiation as a phytosanitary treatment against quarantine pests in purple passionfruit.

Study on the Varying Patterns of Total Phospholipids, Selenium, Phosphorus, Reducing Sugar and Total Sugar, Hydrolyzed Amino Acids in the Velvet Antler of Northeast Sika Deer in Growth Period

Directory of Open Access Journals (Sweden)

Wang Shu-li

2016-01-01

Full Text Available In this study, the varying patterns of total phospholipids, selenium, phosphorus, reducing sugar and total sugar, hydrolyzed amino acids in the velvet antler of Northeast sika deer in growth period were evaluated. Eighteen Northeast sika deer were allocated into 6 groups according to the antler shedding time. Results indicated that there was significant difference of the selenium content between any two of the six groups (P<0.05 except that of Group 1 and Group 2 or Group 5 and Group 6. About the phosphorus there was significant difference between any two of the six groups (P<0.05 except that of Group 4 and Group 5 or Group 2 and Group 3 or Group 1 and Group 2. Group 6 had the lowest total Phospholipids content. Both of the reducing sugar and total sugar showed an increasing pattern initially and then decrease gradually.

Radiation dose and radiation risk to foetuses and newborns during X-ray examinations

Energy Technology Data Exchange (ETDEWEB)

Kettunen, A. [Oulu Univ. (Finland)

2004-05-01

to a foetus was not calculated either before or after the pelvic x-ray examination of an expectant mother. The responsibility for counselling an expectant mother about the risk of a radiation dose to the foetus was not determined. In conventional pelvic x-ray examinations, the dose to the foetus varied from 1 to 2 mSv/exposure. A proposal for a guide to good practices in the pelvic x-ray examination of women of reproductive age is given. The effective doses of 118 chest x-ray examinations to 43 newborns (gestational age from 26 to 42 weeks) were estimated. The effective dose from one chest radiograph varied from 7.5 {mu}Sv to 54 {mu}Sv. Retrospectively, the total number of radiation examinations to these newborns totalled 399 during the study; the mean was 9.3 (range 1-40). 98% of the examinations were produced during the first treatment period after birth. The total effective dose per child varied from 0.31 mSv to 3.7 mSv. The radiation risk of fatal childhood cancer due to the mean dose of 0.37 mSv is 3.7*10 -5. (orig.)

Radiation dose and radiation risk to foetuses and newborns during X-ray examinations

International Nuclear Information System (INIS)

Kettunen, A.

2004-05-01

foetus was not calculated either before or after the pelvic x-ray examination of an expectant mother. The responsibility for counselling an expectant mother about the risk of a radiation dose to the foetus was not determined. In conventional pelvic x-ray examinations, the dose to the foetus varied from 1 to 2 mSv/exposure. A proposal for a guide to good practices in the pelvic x-ray examination of women of reproductive age is given. The effective doses of 118 chest x-ray examinations to 43 newborns (gestational age from 26 to 42 weeks) were estimated. The effective dose from one chest radiograph varied from 7.5 μSv to 54 μSv. Retrospectively, the total number of radiation examinations to these newborns totalled 399 during the study; the mean was 9.3 (range 1-40). 98% of the examinations were produced during the first treatment period after birth. The total effective dose per child varied from 0.31 mSv to 3.7 mSv. The radiation risk of fatal childhood cancer due to the mean dose of 0.37 mSv is 3.7*10 -5. (orig.)

Total body irradiation

International Nuclear Information System (INIS)

Novack, D.H.; Kiley, J.P.

1987-01-01

The multitude of papers and conferences in recent years on the use of very large megavoltage radiation fields indicates an increased interest in total body, hemibody, and total nodal radiotherapy for various clinical situations. These include high dose total body irradiation (TBI) to destroy the bone marrow and leukemic cells and provide immunosuppression prior to a bone marrow transplant, high dose total lymphoid irradiation (TLI) prior to bone marrow transplantation in severe aplastic anemia, low dose TBI in the treatment of lymphocytic leukemias or lymphomas, and hemibody irradiation (HBI) in the treatment of advanced multiple myeloma. Although accurate provision of a specific dose and the desired degree of dose homogeneity are two of the physicist's major considerations for all radiotherapy techniques, these tasks are even more demanding for large field radiotherapy. Because most large field radiotherapy is done at an extended distance for complex patient geometries, basic dosimetry data measured at the standard distance (isocenter) must be verified or supplemented. This paper discusses some of the special dosimetric problems of large field radiotherapy, with specific examples given of the dosimetry of the TBI program for bone marrow transplant at the authors' hospital

Radiation doses to children with shunt-treated hydrocephalus

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Holmedal, Lise J. [Helse Fonna, Department of Radiology, Stord Hospital, Stord (Norway); Friberg, Eva G.; Boerretzen, Ingelin; Olerud, Hilde [The Norwegian Radiation Protection Authority, Oesteraas (Norway); Laegreid, Liv [Haukeland University Hospital, Department of Paediatrics, Bergen (Norway); Rosendahl, Karen [University of Bergen, Department of Surgical Sciences, Radiology Section, Bergen (Norway); Great Ormond Street Hospital for Children, Department of Diagnostic Radiology, London (United Kingdom)

2007-12-15

Children with shunt-treated hydrocephalus are still followed routinely with frequent head CT scans. To estimate the effective dose, brain and lens doses from these examinations during childhood, and to assess dose variation per examination. All children born between 1983 and 1995 and treated for hydrocephalus between 1983 and 2002 were included. We retrospectively registered the number of examinations and the applied scan parameters. The effective dose was calculated using mean conversion factors from the CT dose index measured free in air, while doses to the lens and brain were estimated using tabulated CT dose index values measured in a head phantom. A total of 687 CT examinations were performed in 67 children. The mean effective dose, lens dose and brain dose to children over 6 months of age were 1.2 mSv, 52 mGy and 33 mGy, respectively, and the corresponding doses to younger children were 3.2 mSv, 60 mGy and 48 mGy. The effective dose per CT examination varied by a factor of 64. None of the children was exposed to doses known to cause deterministic effects. However, since the threshold for radiation-induced damage is not known with certainty, alternative modalities such as US and MRI should be used whenever possible. (orig.)

Effect of radiation dose rate and cyclophosphamide on pulmonary toxicity after total body irradiation in a mouse model

International Nuclear Information System (INIS)

Safwat, Akmal; Nielsen, Ole S.; El-Badawy, Samy; Overgaard, Jens

1996-01-01

Purpose: Interstitial pneumonitis (IP) is still a major complication after total body irradiation (TBI) and bone marrow transplantation (BMT). It is difficult to determine the exact role of radiation in this multifactorial complication, especially because most of the experimental work on lung damage was done using localized lung irradiation and not TBI. We have thus tested the effect of radiation dose rate and combining cyclophosphamide (CTX) with single fraction TBI on lung damage in a mouse model for BMT. Methods and Materials: TBI was given as a single fraction at a high dose rate (HDR, 0.71 Gy/min) or a low dose rate (LDR, 0.08 Gy/min). CTX (250 mg/kg) was given 24 h before TBI. Bone marrow transplantation (BMT) was performed 4-6 h after the last treatment. Lung damage was assessed using ventilation rate (VR) and lethality between 28 and 180 days (LD (50(28))-180 ). Results: The LD 50 for lung damage, ± standard error (SE), increased from 12.0 (± 0.2) Gy using single fraction HDR to 15.8 (± 0.6) Gy using LDR. Adding CTX shifted the dose-response curves towards lower doses. The LD 50 values for the combined treatment were 5.3 (± 0.2) and 3.5 (± 0.2) Gy for HDR and LDR, respectively. This indicates that the combined effect of CTX and LDR was more toxic than that of combined CTX and HDR. Lung damage evaluated by VR demonstrated two waves of VR increase. The first wave of VR increase occurred after 6 weeks using TBI only and after 3 weeks in the combined CTX-TBI treatment, irrespective of total dose or dose rate. The second wave of VR elevation resembled the IP that follows localized thoracic irradiation in its time of occurrence. Conclusions: Lung damage following TBI could be spared using LDR. However, CTX markedly enhances TBI-induced lung damage. The combination of CTX and LDR is more toxic to the lungs than combining CTX and HDR

Age-dependent radiation dose due to intake of uranium through drinking water in India

International Nuclear Information System (INIS)

Sahoo, S.K.; Mohapatra, S.; Chakrabarty, A.; Sumesh, C.G.; Tripathi, R.M.; Puranik, V.D.

2009-01-01

In the present study, an attempt has been made to estimate the content of uranium in drinking water in various states of India by laser fluorimetry. Depending upon the rate of water intake for the different age groups, the associated radiation dose was calculated. The concentration of uranium varied between 0.1 ± 0.01 and 19.6 ± 1.8 ppb which is much lower than the drinking water guideline value of 60 ppb. The total radiation dose due to ingestion of uranium through drinking water for various age groups is found to vary from 0.14 μSv/y to 48 μSv/y. (author)

Anti-tumor effect of total body irradiation of low doses on WHT/Ht mice

International Nuclear Information System (INIS)

Miyamoto, Miyako; Sakamoto, Kiyohiko

1987-01-01

The effect of low dose (0.05 - 1.0 Gy) of total body irradiation (TBI) on non-tumor bearing and tumor bearing mice were investigated. Mice received TBI of 0.1 Gy during 6 - 12 hours before tumor cell inoculation demonstrated to need larger number of tumor cells (approximately 2.5 times) for 50 per cent tumor incidence, compared to recipient mice not to receive TBI. On the other hand, in tumor bearing mice given 0.1 Gy of TBI only tumor cell killing effect was not detected, however enhancement of tumor cell killing effect and prolonged growth delay were observed when tumor bearing mice were treated with 0.1 Gy of TBI in combined with local irradiation on tumors, especially cell killing effect was remarkable in dose range over 6 Gy of local exposure. The mechanism of the effect of 0.1 Gy TBI is considered to be host mediated reactions from the other our experimental results. (author)

Enrichment increases hippocampal neurogenesis independent of blood monocyte-derived microglia presence following high-dose total body irradiation.

Science.gov (United States)

Ruitenberg, Marc J; Wells, Julia; Bartlett, Perry F; Harvey, Alan R; Vukovic, Jana

2017-06-01

Birth of new neurons in the hippocampus persists in the brain of adult mammals and critically underpins optimal learning and memory. The process of adult neurogenesis is significantly reduced following brain irradiation and this correlates with impaired cognitive function. In this study, we aimed to compare the long-term effects of two environmental paradigms (i.e. enriched environment and exercise) on adult neurogenesis following high-dose (10Gy) total body irradiation. When housed in standard (sedentary) conditions, irradiated mice revealed a long-lasting (up to 4 months) deficit in neurogenesis in the granule cell layer of the dentate gyrus, the region that harbors the neurogenic niche. This depressive effect of total body irradiation on adult neurogenesis was partially alleviated by exposure to enriched environment but not voluntary exercise, where mice were single-housed with unlimited access to a running wheel. Exposure to voluntary exercise, but not enriched environment, did lead to significant increases in microglia density in the granule cell layer of the hippocampus; our study shows that these changes result from local microglia proliferation rather than recruitment and infiltration of circulating Cx 3 cr1 +/gfp blood monocytes that subsequently differentiate into microglia-like cells. In summary, latent neural precursor cells remain present in the neurogenic niche of the adult hippocampus up to 8 weeks following high-dose total body irradiation. Environmental enrichment can partially restore the adult neurogenic process in this part of the brain following high-dose irradiation, and this was found to be independent of blood monocyte-derived microglia presence. Crown Copyright © 2017. Published by Elsevier Inc. All rights reserved.

Effect of different doses of aerobic exercise on total white blood cell (WBC and WBC subfraction number in postmenopausal women: results from DREW.

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Neil M Johannsen

Full Text Available BACKGROUND: Elevated total white blood cell (WBC count is associated with an increased risk of coronary heart disease and death. Aerobic exercise is associated with lower total WBC, neutrophil, and monocyte counts. However, no studies have evaluated the effect of the amount of aerobic exercise (dose on total WBC and WBC subfraction counts. PURPOSE: To examine the effects of 3 different doses of aerobic exercise on changes in total WBC and WBC subfraction counts and independent effects of changes in fitness, adiposity, markers of inflammation (IL-6, TNF-α, C-reactive protein, fasting glucose metabolism, and adiponectin. METHODS: Data from 390 sedentary, overweight/obese postmenopausal women from the DREW study were used in these analyses. Women were randomized to a non-exercise control group or one of 3 exercise groups: energy expenditure of 4, 8, or 12 kcal kg(-1⋅week(-1 (KKW for 6 months at an intensity of 50% VO2peak. RESULTS: A dose-dependent decrease in total WBC counts (trend P = 0.002 was observed with a significant decrease in the 12KKW group (-163.1±140.0 cells/µL; mean±95%CI compared with the control (138.6±144.7 cells/µL. A similar response was seen in the neutrophil subfraction (trend P = 0.001 with a significant decrease in the 12KKW group (-152.6±115.1 cells/µL compared with both the control and 4KKW groups (96.4±119.0 and 21.9±95.3 cells/µL, respectively and in the 8KKW group (-102.4±125.0 cells/µL compared with the control. When divided into high/low baseline WBC categories (median split, a dose-dependent decrease in both total WBCs (P = 0.003 and neutrophils (P<0.001 was observed in women with high baseline WBC counts. The effects of exercise dose on total WBC and neutrophil counts persisted after accounting for significant independent effects of change in waist circumference and IL-6. CONCLUSION: Aerobic exercise training reduces total WBC and neutrophil counts, in a dose-dependent manner, in

The carcinogenic risk of high dose total body irradiation in non-human primates

International Nuclear Information System (INIS)

Broerse, J.J.; Bartstra, R.W.; Bekkum, D.W. van; Hage, M.H. van der; Zurcher, C.; Zwieten, M.J. van; Hollander, C.F.

2000-01-01

High dose total body irradiation (TBI) in combination with chemotherapy, followed by rescue with bone marrow transplantation (BMT), is increasingly used for the treatment of haematological malignancies. With the increasing success of this treatment and its current introduction for treating refractory autoimmune diseases the risk of radiation carcinogenesis is of growing concern. Studies on turnout induction in non-human primates are of relevance in this context since the response of this species to radiation does not differ much from that in man. Since the early sixties, studies have been performed on acute effects in Rhesus monkeys and the protective action of bone marrow transplantation after irradiation with X-rays (average total body dose 6.8 Gy) and fission neutrons (average dose 3.4 Gy). Of those monkeys, which were irradiated and reconstituted with autologous bone marrow, 20 animals in the X-irradiated group and nine animals in the neutron group survived more than 3 years. A group of 21 non-irradiated Rhesus monkeys of a comparable age distribution served as controls. All animals were regularly screened for the occurrence of neoplasms. Complete necropsies were performed after natural death or euthanasia. At post-irradiation intervals of 4-21 years an appreciable number of tumours was observed. In the neutron irradiated group eight out of nine animals died with one or more malignant tumours. In the X-irradiated group this fraction was 10 out of 20. The tumours in the control group, in seven out of the 21 animals, appeared at much older a-e compared with those in the irradiated cohorts. The histogenesis of the tumours was diverse with a preponderance of renal carcinoma, sarcomas among which osteosarcormas, and malignant glomus tumours in the irradiated groups. When corrected for competing risks, the carcinogenic risk of TBI in the Rhesus monkeys is similar to that derived from the studies of the Japanese atomic bomb survivors. The increase of the risk by a

The role of low-dose total body irradiation in treatment of non-Hodgkin's lymphoma: a new look at an old method

International Nuclear Information System (INIS)

Safwat, A.

2000-01-01

The use of low-dose total body irradiation (LTBI) in treatment of lymphomatous malignancies dates back to the 1920s. The usual practice was to give very low individual TBI fraction sizes (0. 1-0.25 Gy) several times a week to a total dose of 1.5-2 Gy. Despite this very low total dose, LTBI could induce long term remissions and was always as effective as the chemotherapy to which it was compared. In modem radiotherapy, LTBI is still a valid option in treatment of chronic lymphocytic leukaemia (CLL) and the advanced stages of indolent low-grade non-Hodgkin's lymphoma (NHL). Its use in the early stages of low-grade NHL is under investigation in a large multi-institutional trial. The efficacy of LTBI is believed to stem from three mechanisms, namely; immune-enhancement, induction of apoptosis, and the intrinsic hypersensitivity to low-radiation doses demonstrated in many cell lines and tumour systems. Thus, LTBI seems to provide 'alternative' mechanisms of action against cancer cells. This should encourage researchers to explore strategies that integrate LTBI in new and innovative experimental treatment protocols that explore the possible synergism between LTBI and chemotherapy, biological response modifiers and/or immunotherapy. The increased incidence of secondary leukaemia that occurs when LTBI is combined with alkylating agents and/or total lymphoid irradiation should be kept in mind when designing such protocols as it may limit the use of LTBI in highly curable diseases and young patients in whom long survival is expected. (author)

A rapid infusion protocol is safe for total dose iron polymaltose: time for change.

Science.gov (United States)

Garg, M; Morrison, G; Friedman, A; Lau, A; Lau, D; Gibson, P R

2011-07-01

Intravenous correction of iron deficiency by total dose iron polymaltose is inexpensive and safe, but current protocols entail prolonged administration over more than 4 h. This results in reduced patient acceptance, and hospital resource strain. We aimed to assess prospectively the safety of a rapid intravenous protocol and compare this with historical controls. Consecutive patients in whom intravenous iron replacement was indicated were invited to have up to 1.5 g iron polymaltose by a 58-min infusion protocol after an initial 15-min test dose without pre-medication. Infusion-related adverse events (AE) and delayed AE over the ensuing 5 days were also prospectively documented and graded as mild, moderate or severe. One hundred patients, 63 female, mean age 54 (range 18-85) years were studied. Thirty-four infusion-related AE to iron polymaltose occurred in a total of 24 patients--25 mild, 8 moderate and 1 severe; higher than previously reported for a slow protocol iron infusion. Thirty-one delayed AE occurred in 26 patients--26 mild, 3 moderate and 2 severe; similar to previously reported. All but five patients reported they would prefer iron replacement through the rapid protocol again. The presence of inflammatory bowel disease (IBD) predicted infusion-related reactions (54% vs 14% without IBD, P cost, resource utilization and time benefits for the patient and hospital system. © 2011 The Authors. Internal Medicine Journal © 2011 Royal Australasian College of Physicians.

Pattern imprinting in deep sub-micron static random access memories induced by total dose irradiation

Science.gov (United States)

Zheng, Qi-Wen; Yu, Xue-Feng; Cui, Jiang-Wei; Guo, Qi; Ren, Di-Yuan; Cong, Zhong-Chao; Zhou, Hang

2014-10-01

Pattern imprinting in deep sub-micron static random access memories (SRAMs) during total dose irradiation is investigated in detail. As the dose accumulates, the data pattern of memory cells loading during irradiation is gradually imprinted on their background data pattern. We build a relationship between the memory cell's static noise margin (SNM) and the background data, and study the influence of irradiation on the probability density function of ΔSNM, which is the difference between two data sides' SNMs, to discuss the reason for pattern imprinting. Finally, we demonstrate that, for micron and deep sub-micron devices, the mechanism of pattern imprinting is the bias-dependent threshold shift of the transistor, but for a deep sub-micron device the shift results from charge trapping in the shallow trench isolation (STI) oxide rather than from the gate oxide of the micron-device.

Results of Hematopoietic Stem Cell Transplantation After Treatment With Different High-Dose Total-Body Irradiation Regimens in Five Dutch Centers

International Nuclear Information System (INIS)

Loes van Kempen-Harteveld, M.; Brand, Ronald; Kal, Henk B.; Verdonck, Leo F.; Hofman, Pieter; Schattenberg, Anton V.; Maazen, Richard W. van der; Cornelissen, Jan J.; Eijkenboom, Wil M.H.; Lelie, Johannes P. van der; Oldenburger, Foppe; Barge, Renee M.; Biezen, Anja van; Vossen, Jaak M.J.J.; Noordijk, Evert M.; Struikmans, Henk

2008-01-01

Purpose: To evaluate results of high-dose total-body irradiation (TBI) regimens for hematopoietic stem cell transplantation. Methods and Materials: A total of 1,032 patients underwent TBI in one or two fractions before autologous or allogeneic hematologic stem cell transplantation for acute leukemia and non-Hodgkin's lymphoma. The TBI regimens were normalized by using the biological effective dose (BED) concept. The BED values were divided into three dose groups. Study end points were relapse incidence (RI), non-relapse mortality (NRM), relapse-free survival (RFS), and overall survival (OS). Multivariate analysis was performed, stratified by disease. Results: In the highest TBI dose group, RI was significantly lower and NRM was higher vs. the lower dose groups. However, a significant influence on RFS and OS was not found. Relapses in the eye region were found only after shielding to very low doses. Age was of significant influence on OS, RFS, and NRM in favor of younger patients. The NRM of patients older than 40 years significantly increased, and OS decreased. There was no influence of age on RI. Men had better OS and RFS and lower NRM. Type of transplantation significantly influenced RI and NRM for patients with acute leukemia and non-Hodgkin's lymphoma. There was no influence on RFS and OS. Conclusions: Both RI and NRM were significantly influenced by the size of the BED of single-dose or two-fraction TBI regimens; OS and RFS were not. Age was of highly significant influence on NRM, but there was no influence of age on RI. Hyperfractionated TBI with a high BED might be useful, assuming NRM can be reduced

Effect of treatment with single total-dose intravenous iron versus daily oral iron(III-hydroxide polymaltose on moderate puerperal iron-deficiency anemia

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Iyoke CA

2017-05-01

Full Text Available Chukwuemeka Anthony Iyoke,1 Fausta Chioma Emegoakor,1 Euzebus Chinonye Ezugwu,1 Lucky Osaheni Lawani,2 Leonard Ogbonna Ajah,1 Jude Anazoeze Madu,3 Hyginus Uzo Ezegwui,1 Frank Okechukwu Ezugwu4 1Department of Obstetrics and Gynaecology, University of Nigeria, Enugu Campus, 2Department of Obstetrics and Gynaecology, Federal Teaching Hospital, Abakaliki, 3Department of Haematology, University of Nigeria, Nsukka, 4Department of Obstetrics and Gynaecology, College of Medicine, Enugu State University, Enugu, Nigeria Background: Iron-deficiency anemia is the most common nutritional cause of anemia in pregnancy and is often responsible for puerperal anemia. Puerperal anemia can impair postpartum maternal and neonatal well-being. Objective: To determine the effect of treatment of moderate puerperal iron-deficiency anemia using a single intravenous total-dose iron dextran versus daily single dose oral iron(III-hydroxide polymaltose. Methodology: A randomized controlled study in which postpartum women with moderate iron-deficiency anemia were randomized into treatment with either a single total-dose intravenous iron dextran or with daily single doses of oral iron(III-hydroxide polymaltose tablets for 6 weeks. Effects on hemoglobin concentration using either method were compared at 6 weeks postpartum. Analysis was per protocol using SPSS version 17 for windows. P-values ≤0.05 were considered significant. Results: Two hundred eighty-four women were recruited for the study: 142 women received single total dose intravenous infusion of iron dextran while 142 received daily oral iron(III-hydroxide polymaltose tablets. Approximately 84.0% (237/282 completed the study and were analyzed including 81% (115/142 of those randomized to injectable iron therapy compared to 85.9% (122/142 of those randomized to oral treatment. The proportions of women who had attained hemoglobin concentration of at least 10 g/dL by the 6 weeks postpartum visit did not differ

Pulsed dose rate brachytherapy (PDR): an analysis of the technique at 2 years

Energy Technology Data Exchange (ETDEWEB)

Thienpont, M [Ghent Rijksuniversiteit (Belgium). Kliniek voor Radiotherapie en Kerngeneeskunde; Van Eijkeren, M; Van Hecke, H; Boterberg, T; De Neve, W

1995-12-01

A total of 154 applications was analysed using a pulsed dose brachytherapy technique for 138 patients over a 2 year period with emphasis on technical aspects influencing the overall treatment time. Vaginal ovoids were used in 59 cases, plastic tubes in 52, a Fletcher-type in 18, vaginal cylinders in 14 and a perineal template in 11 cases. Pulses were given at hourly intervals with a median dose rate of 0.6 Gy per pulse (range 0.4 to 3 Gy). The number of pulses per application varied from 3 to 134 (median 32). The number of dwell positions varied from 1 to 542 over 1 to 18 catheters. Patient related problems were few. The room was entered almost every 77 minutes. We noted 561 status codes in 147 applications. Of the 25 different codes, the most frequent one was due to the door left open when a pulse had to be given (35%) or due to constriction of the plastic catheters at the transfer tube junction (26%). However, the median total treatment time was increased by only 5 minutes. With pulsed dose rate brachytherapy at hourly pulses we can treat our patients within the planned time despite frequent room entrance and occurrence of an appreciable number of status codes. This technique seems to fulfill its promise to replace low dose rate brachytherapy.

Time- and radiation-dose dependent changes in the plasma proteome after total body irradiation of non-human primates: Implications for biomarker selection.

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Stephanie D Byrum

Full Text Available Acute radiation syndrome (ARS is a complex multi-organ disease resulting from total body exposure to high doses of radiation. Individuals can be exposed to total body irradiation (TBI in a number of ways, including terrorist radiological weapons or nuclear accidents. In order to determine whether an individual has been exposed to high doses of radiation and needs countermeasure treatment, robust biomarkers are needed to estimate radiation exposure from biospecimens such as blood or urine. In order to identity such candidate biomarkers of radiation exposure, high-resolution proteomics was used to analyze plasma from non-human primates following whole body irradiation (Co-60 at 6.7 Gy and 7.4 Gy with a twelve day observation period. A total of 663 proteins were evaluated from the plasma proteome analysis. A panel of plasma proteins with characteristic time- and dose-dependent changes was identified. In addition to the plasma proteomics study reported here, we recently identified candidate biomarkers using urine from these same non-human primates. From the proteomic analysis of both plasma and urine, we identified ten overlapping proteins that significantly differentiate both time and dose variables. These shared plasma and urine proteins represent optimal candidate biomarkers of radiation exposure.

TU-CD-304-04: Scanning Field Total Body Irradiation Using Dynamic Arc with Variable Dose Rate and Gantry Speed

Energy Technology Data Exchange (ETDEWEB)

Yi, B; Xu, H; Mutaf, Y; Prado, K [Univ. of Maryland School Of Medicine, Baltimore, MD (United States)

2015-06-15

Purpose: Enable a scanning field total body irradiation (TBI) technique, using dynamic arcs, which is biologically equivalent to a moving couch TBI. Methods: Patient is treated slightly above the floor and the treatment field scans across the patient by a moving gantry. MLC positions change during gantry motion to keep same field opening at the level of the treatment plane (170 cm). This is done to mimic the same geometry as the moving couch TBI technique which has been used in our institution for over 10 years. The dose rate and the gantry speed are determined considering a constant speed of the moving field, variations in SSD and slanted depths resulting from oblique gantry angles. An Eclipse (Varian) planning system is commissioned to accommodate the extended SSD. The dosimetric foundations of the technique have been thoroughly investigated using phantom measurements. Results: Dose uniformity better than 2% across 180 cm length at 10cm depth is achieved by moving the gantry from −55 to +55 deg. Treatment range can be extended by increasing gantry range. No device such as a gravity-oriented compensator is needed to achieve a uniform dose. It is feasible to modify the dose distribution by adjusting the dose rate at each gantry angle to compensate for body thickness differences. Total treatment time for 2 Gy AP/PA fields is 40–50 minutes excluding patient set up time, at the machine dose rate of 100 MU/min. Conclusion: This novel yet transportable moving field technique enables TBI treatment in a small treatment room with less program development preparation than other techniques. Treatment length can be extended per need, and. MLC-based thickness compensation and partial lung blocking are also possible.

Pattern imprinting in deep sub-micron static random access memories induced by total dose irradiation

International Nuclear Information System (INIS)

Zheng Qi-Wen; Yu Xue-Feng; Cui Jiang-Wei; Guo Qi; Ren Di-Yuan; Cong Zhong-Chao; Zhou Hang

2014-01-01

Pattern imprinting in deep sub-micron static random access memories (SRAMs) during total dose irradiation is investigated in detail. As the dose accumulates, the data pattern of memory cells loading during irradiation is gradually imprinted on their background data pattern. We build a relationship between the memory cell's static noise margin (SNM) and the background data, and study the influence of irradiation on the probability density function of ΔSNM, which is the difference between two data sides' SNMs, to discuss the reason for pattern imprinting. Finally, we demonstrate that, for micron and deep sub-micron devices, the mechanism of pattern imprinting is the bias-dependent threshold shift of the transistor, but for a deep sub-micron device the shift results from charge trapping in the shallow trench isolation (STI) oxide rather than from the gate oxide of the micron-device. (condensed matter: structural, mechanical, and thermal properties)

Use of BEIR V and UNSCEAR 1988 in radiation risk assessment: Lifetime total cancer mortality risk estimates at low doses and low dose rates for low-LET radiation

International Nuclear Information System (INIS)

1992-12-01

In November 1986, the Department of Defense (DoD) asked the Committee on Interagency Radiation Research and Policy Coordination (CIRRPC) to develop a coordinated Federal position on risk assessment for low levels of ionizing radiation. Since Federal risk assessment activities are based primarily on the scientific data and analyses in authoritative review documents prepared by groups like the National Academy of Sciences' Committee on the Biological Effects of Ionizing Radiation (BEIR), the National Council on Radiation Protection and Measurements (NCRP) and the United Nations' Scientific Committee on the Effects of Atomic Radiation (UNSCEAR), DoD proposed that the CIRRPC Science Panel undertake the task of providing coordinated interagency positions on the use of information in the reports of such groups. The practice has been for individual Federal agencies to interpret and decide independently how to use the information provided in such reports. As a result of its deliberations, the Subpanel recommends two nominal risk estimates for lifetime total cancer mortality following whole-body exposure to low levels of low-LET ionizing radiation, one for the general population and one for the working-age population (see Section II). The recommended risk estimates reflect the general agreement of information in BEIR V and UNSCEAR 1988 for total cancer mortality. The Subpanel's risk estimates and associated statements are intended to meet the needs of the Federal agencies for: (a) values that are current; (b) values that are relevant to the low-dose and low dose-rate ionizing radiation exposures principally encountered in carrying out Federal responsibilities; (c) a statement of the change in the estimates of lifetime total cancer mortality relative to estimates in previous authoritative review documents; and (d) a practical statement on the scientific uncertainty associated with applying the lifetime total cancer mortality values at very low doses

Total scalp irradiation using helical tomotherapy

International Nuclear Information System (INIS)

Orton, Nigel; Jaradat, Hazim; Welsh, James; Tome, Wolfgang

2005-01-01

Homogeneous irradiation of the scalp poses technical and dosimetric challenges due to the extensive, superficial, curved treatment volume. Conventional treatments on a linear accelerator use multiple matched electron fields or a combination of electron and photon fields. Problems with these techniques include dose heterogeneity in the target due to varying source-to-skin distance (SSD) and angle of beam incidence, significant dose to the brain, and the potential for overdose or underdose at match lines between the fields. Linac-based intensity-modulated radiation therapy (IMRT) plans have similar problems. This work presents treatment plans for total scalp irradiation on a helical tomotherapy machine. Helical tomotherapy is well-suited for scalp irradiation because it has the ability to deliver beamlets that are tangential to the scalp at all points. Helical tomotherapy also avoids problems associated with field matching and use of more than one modality. Tomotherapy treatment plans were generated and are compared to plans for treatment of the same patient on a linac. The resulting tomotherapy plans show more homogeneous target dose and improved critical structure dose when compared to state-of-the-art linac techniques. Target equivalent uniform dose (EUD) for the best tomotherapy plan was slightly higher than for the linac plan, while the volume of brain tissue receiving over 30 Gy was reduced by two thirds. Furthermore, the tomotherapy plan can be more reliably delivered than linac treatments, because the patient is aligned prior to each treatment based on megavoltage computed tomography (MVCT)

An updated fracture-flow model for total-system performance assessment of Yucca Mountain

International Nuclear Information System (INIS)

Gauthier, J.H.

1994-01-01

Improvements have been made to the fracture-flow model being used in the total-system performance assessment of a potential high-level radioactive waste repository at Yucca Mountain, Nevada. The open-quotes weeps modelclose quotes now includes (1) weeps of varied sizes, (2) flow-pattern fluctuations caused by climate change, and (3) flow-pattern perturbations caused by repository heat generation. Comparison with the original weeps model indicates that allowing weeps of varied sizes substantially reduces the number of weeps and the number of containers contacted by weeps. However, flow-pattern perturbations caused by either climate change or repository heat generation greatly increases the number of containers contacted by weeps. In preliminary total-system calculations, using a phenomenological container-failure and radionuclide-release model, the weeps model predicts that radionuclide releases from a high-level radioactive waste repository at Yucca Mountain will be below the EPA standard specified in 40 CFR 191, but that the maximum radiation dose to an individual could be significant. Specific data from the site are required to determine the validity of the weep-flow mechanism and to better determine the parameters to which the dose calculation is sensitive

An updated fracture-flow model for total-system performance assessment of Yucca Mountain

International Nuclear Information System (INIS)

Gauthier, J.H.

1994-01-01

Improvements have been made to the fracture-flow model being used in the total-system performance assessment of a potential high-level radioactive waste repository at Yucca Mountain, Nevada. The ''weeps model'' now includes (1) weeps of varied sizes, (2) flow-pattern fluctuations caused by climate change, and (3) flow-pattern perturbations caused by repository heat generation. Comparison with the original weeps model indicates that allowing weeps of varied sizes substantially reduces the number of weeps and the number of containers contacted by weeps. However, flow-pattern perturbations caused by either climate change or repository heat generation greatly increases the number of containers contacted by weeps. In preliminary total-system calculations, using a phenomenological container-failure and radionuclide-release model, the weeps model predicts that radionuclide releases from a high-level radioactive waste repository at Yucca Mountain will be below the EPA standard specified in 40 CFR 191, but that the maximum radiation dose to an individual could be significant. Specific data from the site are required to determine the validity of the weep-flow mechanism and to better determine the parameters to which the dose calculation is sensitive

Radiobiological basis of total body irradiation with different dose rate and fractionation: repair capacity of hemopoietic cells

International Nuclear Information System (INIS)

Song, C.W.; Kim, T.H.; Khan, F.M.; Kersey, J.H.; Levitt, S.H.

1981-01-01

Total body irradiation (TBI) followed by bone marrow transplantation is being used in the treatment of malignant or non-malignant hemopoietic disorders. It has been believed that the ability of hemopoietic cells to repair sublethal radiation damage is negligible. Therefore, several schools of investigators suggested that TBI in a single exposure at extremely low dose rate (5 rad/min) over several hours, or in several fractions in 2-3 days, should yield a higher therapeutic gain, as compared with a single exposure at a high dose rate (26 rad/min). We reviewed the existing data in the literature, in particular, the response of hemopoietic cells to fractionated doses of irradiation and found that the repair capacity of both malignant and non-malignant hemopoietic cells might be greater than has been thought. It is concluded that we should not underestimate the ability of hemopoietic cells to repair sublethal radiation damage in using TBI

Recent advances in understanding total-dose effects in bipolar transistors

International Nuclear Information System (INIS)

Schrimpf, R.D.

1996-01-01

Gain degradation in irradiated bipolar transistors can be a significant problem, particularly in linear integrated circuits. In many bipolar technologies, the degradation is greater for irradiation at low dose rates than it is for typical laboratory dose rates. Ionizing radiation causes the base current in bipolar transistors to increase, due to the presence of net positive charge in the oxides covering sensitive device areas and increases in surface recombination velocity. Understanding the mechanisms responsible for radiation-induced gain degradation in bipolar transistors is important in developing appropriate hardness assurance methods. This paper reviews recent modeling and experimental work, with the emphasis on low-dose-rate effects. A promising hardness assurance method based on irradiation at elevated temperatures is described

Determination of 210Po in leafy vegetables and annual effective dose assessment to the inhabitants of Mumbai city, India

International Nuclear Information System (INIS)

Dubey, J.S.; Sahoo, S.K.; Mohapatra, S.; Patra, A.C.; Lenka, P.; Ravi, P.M.; Tripathi, R.M.; Nair, A.

2014-01-01

Present study deals with the measurement of activity concentration of 210 Po in leafy vegetable of Mumbai city and corresponding ingestion dose assessment to the population. 210 Po activity levels ranged from 44.5-183.3 with an average value of 81.8 mBq/kg. Minimum activity of 210 Po was found in shepu and maximum in methi. The concentration reported here is slightly more than the UNSCEAR value. The estimated total effective dose was found to vary from 0.3 - 1.4 with an average value of 0.6 μSv/y, which is about 1% of global average total ingestion dose due to 210 Po. (author)

Low-Dose Total Skin Electron Beam Therapy as a Debulking Agent for Cutaneous T-Cell Lymphoma: An open-label prospective phase II study

DEFF Research Database (Denmark)

Kamstrup, M R; Lindahl, Lise Maria; Gniadecki, R

2012-01-01

Background: Total skin electron beam therapy (TSEBT) is a powerful treatment for cutaneous T-cell lymphomas (CTCL). Based on the occurrence of relapses with low radiation doses, doses of 30-36 Gy are commonly used but most patients still eventually relapse and repeat treatment courses are limited...... due to the cumulative toxicity. Complete response rates are about 60-90% for T2-4 stages with a 5-year relapse-free survival of 10-25% for stages IB-III. Objectives: To evaluate prospectively the efficacy of low-dose TSEBT (10 Gy) in terms of complete cutaneous response rate, overall response rate...... and response duration in CTCL. Methods: Ten patients with stage IB-IV mycosis fungoides (MF) were treated in an open-label manner with 4 fractions of 1 Gy/week TSEB to a total skin dose of 10 Gy. Treatment responses were assessed at 1 and 3 months after treatment and subsequently at least every 6 months...

4D cone beam CT-based dose assessment for SBRT lung cancer treatment

International Nuclear Information System (INIS)

Cai, Weixing; Dhou, Salam; Cifter, Fulya; Myronakis, Marios; Hurwitz, Martina H; Williams, Christopher L; Berbeco, Ross I; Seco, Joao; Lewis, John H

2016-01-01

The purpose of this research is to develop a 4DCBCT-based dose assessment method for calculating actual delivered dose for patients with significant respiratory motion or anatomical changes during the course of SBRT. To address the limitation of 4DCT-based dose assessment, we propose to calculate the delivered dose using time-varying (‘fluoroscopic’) 3D patient images generated from a 4DCBCT-based motion model. The method includes four steps: (1) before each treatment, 4DCBCT data is acquired with the patient in treatment position, based on which a patient-specific motion model is created using a principal components analysis algorithm. (2) During treatment, 2D time-varying kV projection images are continuously acquired, from which time-varying ‘fluoroscopic’ 3D images of the patient are reconstructed using the motion model. (3) Lateral truncation artifacts are corrected using planning 4DCT images. (4) The 3D dose distribution is computed for each timepoint in the set of 3D fluoroscopic images, from which the total effective 3D delivered dose is calculated by accumulating deformed dose distributions. This approach is validated using six modified XCAT phantoms with lung tumors and different respiratory motions derived from patient data. The estimated doses are compared to that calculated using ground-truth XCAT phantoms. For each XCAT phantom, the calculated delivered tumor dose values generally follow the same trend as that of the ground truth and at most timepoints the difference is less than 5%. For the overall delivered dose, the normalized error of calculated 3D dose distribution is generally less than 3% and the tumor D95 error is less than 1.5%. XCAT phantom studies indicate the potential of the proposed method to accurately estimate 3D tumor dose distributions for SBRT lung treatment based on 4DCBCT imaging and motion modeling. Further research is necessary to investigate its performance for clinical patient data. (paper)

Single dose total lymphoid irradiation combined with cyclophosphamide as immunosuppression for human marrow transplantation in aplastic anemia

International Nuclear Information System (INIS)

Kim, T.H.; Kersey, J.H.; Khan, F.M.; Sewchand, W.; Ramsey, N.; Krivit, W.; Coccia, P.; Nesbit, M.E.; Levitt, S.H.

1979-01-01

Six patients with aplastic anemia underwent bone marrow transplantation following conditioning with high dose cyclophosphamide and single dose total lymphoid irradiation with 750 rad, 26 rad/min at the midplane of the patient. They all received bone marrow from human leukocyte antigens/mixed lymphocyte culture (HLA/MLC) matched siblings. Five of 6 patients were alive without complications at 12, 11, 7, 4 and 4 months respectively. The remaining patient died from sepis which he had prior to transplantation. There were no graft rejection, graft-vs-Host Disease (GVHD) or interstitial pneumonitis among these patients. The procedure was well tolerated with minimal side effects. The results will be compared with those of groups whose bone marrow was previously transplanted with different immunosuppressive methods

Radiation dose reduction in digital plain radiography of the knee after total knee arthroplasty; Dosisreduktion in der digitalen Radiografie des Kniegelenkes nach endoprothetischem Gelenkersatz

Energy Technology Data Exchange (ETDEWEB)

Kloth, J.K.; Kauczor, H.U.; Weber, M.A. [University Hospital Heidelberg (Germany). Clinic for Diagnostic and Interventional Radiology; Tanner, M.; Ewerbeck, V. [University Hospital Heidelberg (Germany). Center of Orthopedics, Trauma and Spinal Cord Injury; Stiller, W. [German Cancer Research Center (DKFZ), Radiology (E010), Heidelberg (Germany); Burkholder, I. [Univ. of Applied Sciences of the Saarland, Dept. of Nursing and Health, Saarbruecken (Germany)

2015-08-15

To reduce radiation exposure of frequently performed radiographs of the knee in follow-up of total-knee arthroplasty ensuring accurate assessment by using objective quality control criteria. In this prospective randomized study 278 radiographs of the knee in follow-up of total-knee arthroplasty were performed with standard and 37 % reduced radiation dose. The evaluation of the plain-radiographs was conducted using the following criteria: bone-implant interface, implant-surface character, implant-implant discrimination and periarticular heterotopic ossification. Two radiologists evaluated these criteria using a score ranging from 1 (definitely assessable) to 4 (not assessable). If a single criterion had been evaluated with a score ≥ 3 or more than 2 criteria with ≥ 2 points, the radiograph was score das ''not assessable''. The study was designed as non-inferiority-trial. 100 % of examined radiographs were scored as assessable, hence no statistical inferiority between the examinations with standard and reduced dose could be observed. Singular assessment of the defined criteria was likewise dose-independent. Plain-radiography of the knee following total-knee arthroplasty can be performed with 63 % of standard dose without loss of diagnostic validity.

TLD-300 detectors for separate measurement of total and gamma absorbed dose distributions of single, multiple, and moving-field neutron treatments

International Nuclear Information System (INIS)

Rassow, J.

1984-01-01

Fast neutron therapy requirements, because of the poor depth dose characteristic of present therapeutical sources, are at least as complex in treatment plans as photon therapy. The physical part of the treatment planning is very important; however, it is much more complicated than for photons or electrons owing to the need for: Separation of total and gamma absorbed dose distributions (Dsub(T) and Dsub(G)); and more stringent tissue-equivalence conditions of phantoms than in photon therapy. Therefore, methods of clinical dosimetry for the separate determination of total and gamma absorbed dose distributions in irregularly shaped (inhomogeneous) phantoms are needed. A method using TLD-300 (CaF 2 :Tm) detectors is described, which is able to give an approximate solution of the above-mentioned dosimetric requirements. The two independent doses, Dsub(T) and Dsub(G), can be calculated by an on-line computer analysis of the digitalized glow curve of TLD-300 detectors, irradiated with d(14)+Be neutrons of the cyclotron isocentric neutron therapy facility CIRCE in Essen. Results are presented for depth and lateral absorbed dose distributions (Dsub(T) and Dsub(G)) for fixed neutron beams of different field sizes compared with measurements by standard procedures (TE-TE ionization chamber, GM counter) in an A-150 phantom. The TLD-300 results for multiple and moving-field treatments (with and without wedge filters) in a patient simulating irregularly shaped (inhomogeneous) phantoms, are shown together with computer calculations of these dose distributions. The probable causes for some systematic deviations are discussed, which lead to open problems for further investigations owing to features of the detector material and the evaluation method, but mainly to differences in the composition of phantom materials used for the calculations (standard dose distributions) and TLD-300 measurements. (author)

Biological influence from low dose and low-dose rate radiation

International Nuclear Information System (INIS)

Magae, Junji

2007-01-01

Although living organisms have defense mechanisms for radioadaptive response, the influence is considered to vary qualitatively and quantitatively for low dose and high dose, as well as for low-dose rate and high-dose rate. This article describes the bioresponse to low dose and low-dose rate. Among various biomolecules, DNA is the most sensitive to radiation, and accurate replication of DNA is an essential requirement for the survival of living organisms. Also, the influence of active enzymes resulted from the effect of radiation on enzymes in the body is larger than the direct influence of radiation on the body. After this, the article describes the carcinogenic risk by low-dose radiation, and then so-called Hormesis effect to create cancer inhibition effect by stimulating active physiology. (S.K.)

The effect of single and double doses of gamma radiation on pre-rigor mortis filleted saithe

International Nuclear Information System (INIS)

Underdahl, B.; Lunde, G.

1973-01-01

Saithe, caught off the western coast of Norway, were filleted immediately after killing, packed in plastic bags and irradiated using a cobalt-60 source at the Institutt for Atomenergi, Kjeller. The doses were 50, 100, 150, 50+50 and 50+100 krad. All samples were analysed for their total bacterial count, proteolytic activity, ammonia, total volatile acids, trimethylamine oxide, tri- and dimethylamine and formaldehyde. The organoleptic quality was evaluated by a panel of tasters. Double doses were more effective in reducing the total bacterial count than an equivalent single dose. A close relation was found between the bacterial count and the proteolytic activity. The trimethylamine oxide concentration was found to vary between 33 and 44 mg/100 g muscle, decreasing rapidly in non-irradiated fillets to 3 mg/100 g. In non-irradiated fillets trimethylamine oxide was mainly reduced to trimethylamine and in irradiated fillets to dimethylamine and formaldehyde. A split dose of 50+50 krad may have a favourable effect on the total bacterial number, but the analyses of proteolytic activity, the volatile acids and the trimethylamine indicate that a higher proportion of spoilage bacteria survive. The low proteolytic activity and the high content of DMA/FA prove that the split doses of 50+100 krad as compared with a single dose of 150 krad are particularly favourable in the case of saithe. (Auth.)

Updated radiological dose assessment of Bikini and Eneu Islands at Bikini Atoll

International Nuclear Information System (INIS)

Robison, W.L.; Mount, M.E.; Phillips, W.A.; Stuart, M.L.; Thompson, S.E.; Conrado, C.L.; Stoker, A.C.

1982-01-01

This report is part of a continuing effort to refine dose assessments for resettlement options at Bikini Atoll. Radionuclide concentration data developed at Bikini Atoll since 1977 have been used in conjunction with recent dietary information and current dose models to develop the annual dose rate and 30- and 50-y integral doses presented here for Bikini and Eneu Island living patterns. The terrestrial food chain is the most significant exposure pathway--it contributes more than 50% of the total dose--and external gamma exposure is the second most significant pathway. Other pathways evaluated are the marine food chain, drinking water, and inhalation. Cesium-137 produces more than 85% of the predicted dose; 90 Sr is the second most significant radionuclide; 60 Co contributes to the external gamma exposure in varying degrees, but is a small part of the total predicted dose; the transuranic radionuclides contribute a small portion of the total predicted lung and bone doses but do present a long-term source of exposure. Maximum annual dose rates for Bikini Island are about 1 rem/y for the whole body and bone marrow when imported foods are available and about 1.9 rem/y when imports are unavailable. Maximum annual dose rates for Eneu Island when imports are available are 130 mrem/y for the whole body and 136 mrem/y for bone marrow. Similar doses when imported foods are unavailable are 245 and 263 mrem/y, respectively. The 30-y integral doses for Bikini Island are about 23 rem for whole body and bone marrow when imported foods are available and more than 40 rem when imports are unavailable. The Eneu Island 30-y integral doses for whole body and bone marrow are about 3 rem when imports are available and 5.5 and 6.1 rem, respectively, when imports are unavailable. Doses from living patterns involving some combination of Bikini and Eneu Islands fall between the doses listed above for each island separately

New insights into fully-depleted SOI transistor response during total-dose irradiation

International Nuclear Information System (INIS)

Schwank, J.R.; Shaneyfelt, M.R.; Dodd, P.E.; Burns, J.A.; Keast, C.L.; Wyatt, P.W.

1999-01-01

In this paper, we present irradiation results on 2-fully depleted processes (HYSOI6, RKSOI) that show SOI (silicon on insulator) device response can be more complicated than originally suggested by others. The major difference between the 2 process versions is that the RKSOI process incorporates special techniques to minimize pre-irradiation parasitic leakage current from trench sidewalls. Transistors were irradiated at room temperature using 10 keV X-ray source. Worst-case bias configuration for total-dose testing fully-depleted SOI transistors was found to be process dependent. It appears that the worst-case bias for HYPOI6 process is the bias that causes the largest increase in sidewall leakage. The RKSOI process shows a different response during irradiation, the transition response appears to be dominated by charge trapping in the buried oxide. These results have implications for hardness assurance testing. (A.C.)

A reviewed technique for total body electron therapy using a Varian Clinac 2100C/D high dose rate treatment beam facility

International Nuclear Information System (INIS)

Oliver, L.D.; Xuereb, E.M.A.; Last, V.; Hunt, P.B.; Wilfert, A.

1996-01-01

Our (Royal North Shore Hospital) most recent linear accelerator acquisition is a Varian Clinac 2100C/D which has a high dose rate (approximately 25Gy per minute at 1 metre) total body electron option. We investigated the physical characteristics of the electron beam to develop a suitable method of treatment for total body electron therapy. The useful electron beam width is defined as 80cm above and below the reference height. Measurements of the electron dose received from the two angled electron beams showed a critical dependence on the gantry angles. The treatment protocol uses ten different patient angles, fractionated into directly opposing fields and treated seuqentially each day. A full cycle of treatment is completed in five days. (author)

Predicting thyroxine requirements following total thyroidectomy.

Science.gov (United States)

Mistry, Dipan; Atkin, Stephen; Atkinson, Helen; Gunasekaran, Sinnappa; Sylvester, Deborah; Rigby, Alan S; England, R James

2011-03-01

Optimal thyroxine replacement following total thyroidectomy is critical to avoid symptoms of hypothyroidism. The aim of this study was to determine the best formula to determine the initiated replacement dose of levothyroxine immediately following total thyroidectomy. Prospective study. All patients were initiated on 100 μg levothyroxine and titrated to within the reference range for TSH and free T4. Correlations to height, weight, age, lean body mass (LBM), body surface area (BSA) and body mass index (BMI) were calculated. One hundred consecutive adult patients underwent total thyroidectomy for non-malignant disease. Comparison between three methods of levothyroxine dose prediction, aiming for a levothyroxine dose correct to within 25 μg of actual dose required. Correlations were seen between levothyroxine dose and patient age (r=-0.346, Pregression equation was calculated (predicted levothyroxine dose=[0·943 × bodyweight] + [-1.165 × age] + 125.8), simplified to (levothyroxine dose= bodyweight - age + 125) pragmatically. Initiating patients empirically on 100 μg post-operatively showed that 40% of patients achieved target within 25 μg of their required dose; this increased to 59% when using a weight-only dose calculation (1.6 μg/kg) and to 72% using the simplified regression equation. A simple calculated regression equation gives a more accurate prediction of initiated levothyroxine dose following total thyroidectomy, reducing the need for outpatient attendance for dose titration. © 2011 Blackwell Publishing Ltd.

Cancer risk estimates from radiation therapy for heterotopic ossification prophylaxis after total hip arthroplasty

Energy Technology Data Exchange (ETDEWEB)

Mazonakis, Michalis; Berris, Theoharris; Damilakis, John [Department of Medical Physics, Faculty of Medicine, University of Crete, P.O. Box 2208, 71003 Iraklion, Crete (Greece); Lyraraki, Efrossyni [Department of Radiotherapy and Oncology, University Hospital of Iraklion, 71110 Iraklion, Crete (Greece)

2013-10-15

Purpose: Heterotopic ossification (HO) is a frequent complication following total hip arthroplasty. This study was conducted to calculate the radiation dose to organs-at-risk and estimate the probability of cancer induction from radiotherapy for HO prophylaxis.Methods: Hip irradiation for HO with a 6 MV photon beam was simulated with the aid of a Monte Carlo model. A realistic humanoid phantom representing an average adult patient was implemented in Monte Carlo environment for dosimetric calculations. The average out-of-field radiation dose to stomach, liver, lung, prostate, bladder, thyroid, breast, uterus, and ovary was calculated. The organ-equivalent-dose to colon, that was partly included within the treatment field, was also determined. Organ dose calculations were carried out using three different field sizes. The dependence of organ doses upon the block insertion into primary beam for shielding colon and prosthesis was investigated. The lifetime attributable risk for cancer development was estimated using organ, age, and gender-specific risk coefficients.Results: For a typical target dose of 7 Gy, organ doses varied from 1.0 to 741.1 mGy by the field dimensions and organ location relative to the field edge. Blocked field irradiations resulted in a dose range of 1.4–146.3 mGy. The most probable detriment from open field treatment of male patients was colon cancer with a high risk of 564.3 × 10{sup −5} to 837.4 × 10{sup −5} depending upon the organ dose magnitude and the patient's age. The corresponding colon cancer risk for female patients was (372.2–541.0) × 10{sup −5}. The probability of bladder cancer development was more than 113.7 × 10{sup −5} and 110.3 × 10{sup −5} for males and females, respectively. The cancer risk range to other individual organs was reduced to (0.003–68.5) × 10{sup −5}.Conclusions: The risk for cancer induction from radiation therapy for HO prophylaxis after total hip arthroplasty varies considerably by

Cancer risk estimates from radiation therapy for heterotopic ossification prophylaxis after total hip arthroplasty

International Nuclear Information System (INIS)

Mazonakis, Michalis; Berris, Theoharris; Damilakis, John; Lyraraki, Efrossyni

2013-01-01

Purpose: Heterotopic ossification (HO) is a frequent complication following total hip arthroplasty. This study was conducted to calculate the radiation dose to organs-at-risk and estimate the probability of cancer induction from radiotherapy for HO prophylaxis.Methods: Hip irradiation for HO with a 6 MV photon beam was simulated with the aid of a Monte Carlo model. A realistic humanoid phantom representing an average adult patient was implemented in Monte Carlo environment for dosimetric calculations. The average out-of-field radiation dose to stomach, liver, lung, prostate, bladder, thyroid, breast, uterus, and ovary was calculated. The organ-equivalent-dose to colon, that was partly included within the treatment field, was also determined. Organ dose calculations were carried out using three different field sizes. The dependence of organ doses upon the block insertion into primary beam for shielding colon and prosthesis was investigated. The lifetime attributable risk for cancer development was estimated using organ, age, and gender-specific risk coefficients.Results: For a typical target dose of 7 Gy, organ doses varied from 1.0 to 741.1 mGy by the field dimensions and organ location relative to the field edge. Blocked field irradiations resulted in a dose range of 1.4–146.3 mGy. The most probable detriment from open field treatment of male patients was colon cancer with a high risk of 564.3 × 10 −5 to 837.4 × 10 −5 depending upon the organ dose magnitude and the patient's age. The corresponding colon cancer risk for female patients was (372.2–541.0) × 10 −5 . The probability of bladder cancer development was more than 113.7 × 10 −5 and 110.3 × 10 −5 for males and females, respectively. The cancer risk range to other individual organs was reduced to (0.003–68.5) × 10 −5 .Conclusions: The risk for cancer induction from radiation therapy for HO prophylaxis after total hip arthroplasty varies considerably by the treatment parameters, organ

A combination of high dose rate (10X FFF/2400 MU/min/10 MV X-rays) and total low dose (0.5 Gy) induces a higher rate of apoptosis in melanoma cells in vitro and superior preservation of normal melanocytes.

Science.gov (United States)

Sarojini, Sreeja; Pecora, Andrew; Milinovikj, Natasha; Barbiere, Joseph; Gupta, Saakshi; Hussain, Zeenathual M; Tuna, Mehmet; Jiang, Jennifer; Adrianzen, Laura; Jun, Jaewook; Catello, Laurice; Sanchez, Diana; Agarwal, Neha; Jeong, Stephanie; Jin, Youngjin; Remache, Yvonne; Goy, Andre; Ndlovu, Alois; Ingenito, Anthony; Suh, K Stephen

2015-10-01

The aim of this study was to determine the apoptotic effects, toxicity, and radiosensitization of total low dose irradiation delivered at a high dose rate in vitro to melanoma cells, normal human epidermal melanocytes (HEM), or normal human dermal fibroblasts (HDF) and to study the effect of mitochondrial inhibition in combination with radiation to enhance apoptosis in melanoma cells. Cells irradiated using 10X flattening filter-free (FFF) 10 MV X-rays at a dose rate of 400 or 2400 MU/min and a total dose of 0.25-8 Gy were analyzed by cell/colony counting, MitoTracker, MTT, and DNA-damage assays, as well as by quantitative real-time reverse transcriptase PCR in the presence or absence of mitochondrial respiration inhibitors. A dose rate of 2400 MU/min killed on average five-fold more melanoma cells than a dose rate 400 MU/min at a total dose of 0.5 Gy and preserved 80% survival of HEM and 90% survival of HDF. Increased apoptosis at the 2400 MU/min dose rate is mediated by greater DNA damage, reduced cell proliferation, upregulation of apoptotic genes, and downregulation of cell cycle genes. HEM and HDF were relatively unharmed at 2400 MU/min. Radiation induced upregulation of mitochondrial respiration in both normal and cancer cells, and blocking the respiration with inhibitors enhanced apoptosis only in melanoma cells. A high dose rate with a low total dose (2400 MU/min, 0.5 Gy/10X FFF 10 MV X-rays) enhances radiosensitivity of melanoma cells while reducing radiotoxicity toward HEM and HDF. Selective cytotoxicity of melanoma cells is increased by blocking mitochondrial respiration.

Radiological dose reconstruction for birds reconciles outcomes of Fukushima with knowledge of dose-effect relationships

International Nuclear Information System (INIS)

Garnier-Laplace, Jacqueline; Beaugelin-Seiller, Karine; Della-Vedova, Claire; Metivier, Jean-Michel; Ritz, Christian; Mousseau, Timothy A.; Pape Moeller, Anders

2015-01-01

We reconstructed the radiological dose for birds observed at 300 census sites in the 50-km northwest area affected by the accident at the Fukushima Daiichi nuclear power plant over 2011-2014. Substituting the ambient dose rate measured at the census points (from 0.16 to 31 μGy h -1 ) with the dose rate reconstructed for adult birds of each species (from 0.3 to 97 μGy h -1 ), we confirmed that the overall bird abundance at Fukushima decreased with increasing total doses. This relationship was directly consistent with exposure levels found in the literature to induce physiological disturbances in birds. Among the 57 species constituting the observed bird community, we found that 90% were likely chronically exposed at a dose rate that could potentially affect their reproductive success. We quantified a loss of 22.6% of the total number of individuals per increment of one unit log10-transformed total dose (in Gy), over the four-year post-accident period in the explored area. We estimated that a total dose of 0.55 Gy reduced by 50% the total number of birds in the study area over 2011-2014. The data also suggest a significant positive relationship between total dose and species diversity. (authors)

Committed effective dose from thoron daughters inhalation

International Nuclear Information System (INIS)

Campos, M.P.; Pecequilo, B.R.S.

2000-01-01

Mankind's interest in natural radiation exposure levels has increased over the past fifty years and it is now recognized that the most significant contributors to human irradiation by natural sources are the short-lived decay products of radon ( 222 Rn) and thoron ( 220 Rn). Despite the thoron short half-life of 55 s, effective dose from inhalation of thoron an its progeny ( 212 Pb and 212 Bi) must be considered, owing to the high thorium background in countries like Brazil, China and India, for example. The indoor committed effective dose was assessed by air sampling at the thorium purification plant and the nuclear materials storage site of the Instituto de Pesquisas Energeticas e Nucleares; Sao Paulo, Brazil. A total of 21 glass fiber filter samples was analyzed by high resolution gamma ray spectrometry in order to obtain the 212 Pb and 212 Bi activities. The equilibrium equivalent concentration (EEC) varied from 0.3 Bq/m 3 to 6.8 Bq/m 3 for the storage site air samples and from 9.9 Bq/m 3 to 249.8 Bq/m 3 for the thorium purification plant air samples. As retention studies indicate a biological half-life of a few hours inhaled thoron progeny in the human lungs, the main fraction of the potential alpha energy (PAEC) deposited is absorbed in the lungs, meaning negligible to the effective dose the contribution of the dose in other times. The committed effective dose due thoron progeny was performed by compartimental analysis following the ICRP 66 lung compartimental model and ICRP 67 lead compartimental model. The values obtained varied from 0.03 mSv/a to 0.67 mSv/a for the storage site air samples and from 0.12 mSv/a to 6.00 mSv/a for the thorium purification plant air samples. (author)

Low-dose 4D cone-beam CT via joint spatiotemporal regularization of tensor framelet and nonlocal total variation

Science.gov (United States)

Han, Hao; Gao, Hao; Xing, Lei

2017-08-01

Excessive radiation exposure is still a major concern in 4D cone-beam computed tomography (4D-CBCT) due to its prolonged scanning duration. Radiation dose can be effectively reduced by either under-sampling the x-ray projections or reducing the x-ray flux. However, 4D-CBCT reconstruction under such low-dose protocols is prone to image artifacts and noise. In this work, we propose a novel joint regularization-based iterative reconstruction method for low-dose 4D-CBCT. To tackle the under-sampling problem, we employ spatiotemporal tensor framelet (STF) regularization to take advantage of the spatiotemporal coherence of the patient anatomy in 4D images. To simultaneously suppress the image noise caused by photon starvation, we also incorporate spatiotemporal nonlocal total variation (SNTV) regularization to make use of the nonlocal self-recursiveness of anatomical structures in the spatial and temporal domains. Under the joint STF-SNTV regularization, the proposed iterative reconstruction approach is evaluated first using two digital phantoms and then using physical experiment data in the low-dose context of both under-sampled and noisy projections. Compared with existing approaches via either STF or SNTV regularization alone, the presented hybrid approach achieves improved image quality, and is particularly effective for the reconstruction of low-dose 4D-CBCT data that are not only sparse but noisy.

Cumulative total effective whole-body radiation dose in critically ill patients.

Science.gov (United States)

Rohner, Deborah J; Bennett, Suzanne; Samaratunga, Chandrasiri; Jewell, Elizabeth S; Smith, Jeffrey P; Gaskill-Shipley, Mary; Lisco, Steven J

2013-11-01

Uncertainty exists about a safe dose limit to minimize radiation-induced cancer. Maximum occupational exposure is 20 mSv/y averaged over 5 years with no more than 50 mSv in any single year. Radiation exposure to the general population is less, but the average dose in the United States has doubled in the past 30 years, largely from medical radiation exposure. We hypothesized that patients in a mixed-use surgical ICU (SICU) approach or exceed this limit and that trauma patients were more likely to exceed 50 mSv because of frequent diagnostic imaging. Patients admitted into 15 predesignated SICU beds in a level I trauma center during a 30-day consecutive period were prospectively observed. Effective dose was determined using Huda's method for all radiography, CT imaging, and fluoroscopic examinations. Univariate and multivariable linear regressions were used to analyze the relationships between observed values and outcomes. Five of 74 patients (6.8%) exceeded exposures of 50 mSv. Univariate analysis showed trauma designation, length of stay, number of CT scans, fluoroscopy minutes, and number of general radiographs were all associated with increased doses, leading to exceeding occupational exposure limits. In a multivariable analysis, only the number of CT scans and fluoroscopy minutes remained significantly associated with increased whole-body radiation dose. Radiation levels frequently exceeded occupational exposure standards. CT imaging contributed the most exposure. Health-care providers must practice efficient stewardship of radiologic imaging in all critically ill and injured patients. Diagnostic benefit must always be weighed against the risk of cumulative radiation dose.

Total dose radiation effects of pressure sensors fabricated on uni-bond-SOI materials

International Nuclear Information System (INIS)

Zhu Shiyang; Huang Yiping; Wang Jin; Li Anzhen; Shen Shaoqun; Bao Minhang

2001-01-01

Piezoresistive pressure sensors with a twin-island structure were successfully fabricated using high quality Uni-bond-SOI (On Insulator) materials. Since the piezoresistors were structured by the single crystalline silicon overlayer of the SOI wafer and were totally isolated by the buried SiO 2 , the sensors are radiation-hard. The sensitivity and the linearity of the pressure sensors keep their original values after being irradiated by 60 Co γ-rays up to 2.3 x 10 4 Gy(H 2 O). However, the offset voltage of the sensor has a slight drift, increasing with the radiation dose. The absolute value of the offset voltage deviation depends on the pressure sensor itself. For comparison, corresponding polysilicon pressure sensors were fabricated using the similar process and irradiated at the same condition

SU-F-T-600: Influence of Acuros XB and AAA Dose Calculation Algorithms On Plan Quality Metrics and Normal Lung Doses in Lung SBRT

International Nuclear Information System (INIS)

Yaparpalvi, R; Mynampati, D; Kuo, H; Garg, M; Tome, W; Kalnicki, S

2016-01-01

Purpose: To study the influence of superposition-beam model (AAA) and determinant-photon transport-solver (Acuros XB) dose calculation algorithms on the treatment plan quality metrics and on normal lung dose in Lung SBRT. Methods: Treatment plans of 10 Lung SBRT patients were randomly selected. Patients were prescribed to a total dose of 50-54Gy in 3–5 fractions (10?5 or 18?3). Doses were optimized accomplished with 6-MV using 2-arcs (VMAT). Doses were calculated using AAA algorithm with heterogeneity correction. For each plan, plan quality metrics in the categories- coverage, homogeneity, conformity and gradient were quantified. Repeat dosimetry for these AAA treatment plans was performed using AXB algorithm with heterogeneity correction for same beam and MU parameters. Plan quality metrics were again evaluated and compared with AAA plan metrics. For normal lung dose, V_2_0 and V_5 to (Total lung- GTV) were evaluated. Results: The results are summarized in Supplemental Table 1. PTV volume was mean 11.4 (±3.3) cm"3. Comparing RTOG 0813 protocol criteria for conformality, AXB plans yielded on average, similar PITV ratio (individual PITV ratio differences varied from −9 to +15%), reduced target coverage (−1.6%) and increased R50% (+2.6%). Comparing normal lung doses, the lung V_2_0 (+3.1%) and V_5 (+1.5%) were slightly higher for AXB plans compared to AAA plans. High-dose spillage ((V105%PD - PTV)/ PTV) was slightly lower for AXB plans but the % low dose spillage (D2cm) was similar between the two calculation algorithms. Conclusion: AAA algorithm overestimates lung target dose. Routinely adapting to AXB for dose calculations in Lung SBRT planning may improve dose calculation accuracy, as AXB based calculations have been shown to be closer to Monte Carlo based dose predictions in accuracy and with relatively faster computational time. For clinical practice, revisiting dose-fractionation in Lung SBRT to correct for dose overestimates attributable to algorithm

SU-F-T-600: Influence of Acuros XB and AAA Dose Calculation Algorithms On Plan Quality Metrics and Normal Lung Doses in Lung SBRT

Energy Technology Data Exchange (ETDEWEB)

Yaparpalvi, R; Mynampati, D; Kuo, H; Garg, M; Tome, W; Kalnicki, S [Montefiore Medical Center, Bronx, NY (United States)

2016-06-15

Purpose: To study the influence of superposition-beam model (AAA) and determinant-photon transport-solver (Acuros XB) dose calculation algorithms on the treatment plan quality metrics and on normal lung dose in Lung SBRT. Methods: Treatment plans of 10 Lung SBRT patients were randomly selected. Patients were prescribed to a total dose of 50-54Gy in 3–5 fractions (10?5 or 18?3). Doses were optimized accomplished with 6-MV using 2-arcs (VMAT). Doses were calculated using AAA algorithm with heterogeneity correction. For each plan, plan quality metrics in the categories- coverage, homogeneity, conformity and gradient were quantified. Repeat dosimetry for these AAA treatment plans was performed using AXB algorithm with heterogeneity correction for same beam and MU parameters. Plan quality metrics were again evaluated and compared with AAA plan metrics. For normal lung dose, V{sub 20} and V{sub 5} to (Total lung- GTV) were evaluated. Results: The results are summarized in Supplemental Table 1. PTV volume was mean 11.4 (±3.3) cm{sup 3}. Comparing RTOG 0813 protocol criteria for conformality, AXB plans yielded on average, similar PITV ratio (individual PITV ratio differences varied from −9 to +15%), reduced target coverage (−1.6%) and increased R50% (+2.6%). Comparing normal lung doses, the lung V{sub 20} (+3.1%) and V{sub 5} (+1.5%) were slightly higher for AXB plans compared to AAA plans. High-dose spillage ((V105%PD - PTV)/ PTV) was slightly lower for AXB plans but the % low dose spillage (D2cm) was similar between the two calculation algorithms. Conclusion: AAA algorithm overestimates lung target dose. Routinely adapting to AXB for dose calculations in Lung SBRT planning may improve dose calculation accuracy, as AXB based calculations have been shown to be closer to Monte Carlo based dose predictions in accuracy and with relatively faster computational time. For clinical practice, revisiting dose-fractionation in Lung SBRT to correct for dose overestimates

Low-Dose (10-Gy) Total Skin Electron Beam Therapy for Cutaneous T-Cell Lymphoma: An Open Clinical Study and Pooled Data Analysis

Energy Technology Data Exchange (ETDEWEB)

Kamstrup, Maria R., E-mail: mkam0004@bbh.regionh.dk [Department of Dermatology, Bispebjerg Hospital, University of Copenhagen, Copenhagen (Denmark); Gniadecki, Robert [Department of Dermatology, Bispebjerg Hospital, University of Copenhagen, Copenhagen (Denmark); Iversen, Lars [Department of Dermatology, Aarhus University Hospital, Aarhus (Denmark); Skov, Lone [Department of Dermatology, Gentofte Hospital, University of Copenhagen, Copenhagen (Denmark); Petersen, Peter Meidahl [Department of Oncology and Hematology, Rigshospitalet, University of Copenhagen, Copenhagen (Denmark); Loft, Annika [Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, University of Copenhagen, Copenhagen (Denmark); Specht, Lena [Department of Oncology and Hematology, Rigshospitalet, University of Copenhagen, Copenhagen (Denmark)

2015-05-01

Purpose: Cutaneous T-cell lymphomas (CTCLs) are dominated by mycosis fungoides (MF) and Sézary syndrome (SS), and durable disease control is a therapeutic challenge. Standard total skin electron beam therapy (TSEBT) is an effective skin-directed therapy, but the possibility of retreatments is limited to 2 to 3 courses in a lifetime due to skin toxicity. This study aimed to determine the clinical effect of low-dose TSEBT in patients with MF and SS. Methods and Materials: In an open clinical study, 21 patients with MF/SS stages IB to IV were treated with low-dose TSEBT over <2.5 weeks, receiving a total dose of 10 Gy in 10 fractions. Data from 10 of these patients were published previously but were included in the current pooled data analysis. Outcome measures were response rate, duration of response, and toxicity. Results: The overall response rate was 95% with a complete cutaneous response or a very good partial response rate (<1% skin involvement with patches or plaques) documented in 57% of the patients. Median duration of overall cutaneous response was 174 days (5.8 months; range: 60-675 days). TSEBT-related acute adverse events (grade 1 or 2) were observed in 60% of patients. Conclusions: Low-dose (10-Gy) TSEBT offers a high overall response rate and is relatively safe. With this approach, reirradiation at times of relapse or progression is likely to be less toxic than standard dose TSEBT. It remains to be established whether adjuvant and combination treatments can prolong the beneficial effects of low-dose TSEBT.

Effects of total dose of ionizing radiation on integrated circuits

Energy Technology Data Exchange (ETDEWEB)

Silveira, Marcilei A.G.; Cirne, K.H.; Gimenez, S.; Santos, R.B.B. [Centro Universitario da FEI, Sao Bernardo do Campo, SP (Brazil); Added, N.; Barbosa, M.D.L.; Medina, N.H.; Tabacniks, M.H. [Universidade de Sao Paulo (IF/USP), SP (Brazil). Inst. de Fisica; Lima, J.A. de; Seixas Junior, L.E.; Melo, W. [Centro de Tecnologia da Informacao Paulo Archer, Sao Paulo, SP (Brazil)

2011-07-01

Full text: The study of ionizing radiation effects on materials used in electronic devices is of great relevance for the progress of global technological development and, particularly, it is a necessity in some strategic areas in Brazil. Electronic circuits are strongly influenced by radiation and the need for IC's featuring radiation hardness is largely growing to meet the stringent environment in space electronics. On the other hand, aerospace agencies are encouraging both scientific community and semiconductors industry to develop hardened-by-design components using standard manufacturing processes to achieve maximum performance, while significantly reducing costs. To understand the physical phenomena responsible for changes in devices exposed to ionizing radiation several kinds of radiation should then be considered, among them alpha particles, protons, gamma and X-rays. Radiation effects on the integrated circuits are usually divided into two categories: total ionizing dose (TID), a cumulative dose that shifts the threshold voltage and increases transistor's off-state current; single events effects (SEE), a transient effect which can deposit charge directly into the device and disturb the properties of electronic circuits. TID is one of the most common effects and may generate degradation in some parameters of the CMOS electronic devices, such as the threshold voltage oscillation, increase of the sub-threshold slope and increase of the off-state current. The effects of ionizing radiation are the creation of electron-hole pairs in the oxide layer changing operation mode parameters of the electronic device. Indirectly, there will be also changes in the device due to the formation of secondary electrons from the interaction of electromagnetic radiation with the material, since the charge carriers can be trapped both in the oxide layer and in the interface with the oxide. In this work we have investigated the behavior of MOSFET devices fabricated with

Effect of high-dose preoperative methylprednisolone on recovery after total hip arthroplasty

DEFF Research Database (Denmark)

Lunn, T H; Andersen, Lasse Østergaard; Kristensen, B B

2013-01-01

(IQR) (95% CI), MP vs placebo]: 23.5 (23.3-23.7) (17.8-43.8) vs 23.5 (23.0-23.8) (20.0-46.8) h, the mean difference (95% CI) being -1.3 (-4.7 to 2.2) h, P=0.65. Overall pain for the first 24 h after surgery was significantly reduced in the MP vs the placebo group (PMP 125 mg i.v. before surgery added......BACKGROUND: /st>High-dose glucocorticoid may reduce postsurgical pain and improve recovery. We hypothesized that 125 mg methylprednisolone (MP) would reduce time to meet functional discharge criteria after total hip arthroplasty (THA). METHODS: /st>Forty-eight patients undergoing unilateral THA...... under spinal anaesthesia were consecutively included in this randomized, double-blind, placebo-controlled trial receiving preoperative i.v. MP or saline. All patients received a standardized, multimodal analgesic regime with paracetamol, celecoxib, and gabapentin. The primary outcome was time to meet...

Quantitative analysis of biological responses to low dose-rate γ-radiation, including dose, irradiation time, and dose-rate

International Nuclear Information System (INIS)

Magae, J.; Furukawa, C.; Kawakami, Y.; Hoshi, Y.; Ogata, H.

2003-01-01

Full text: Because biological responses to radiation are complex processes dependent on irradiation time as well as total dose, it is necessary to include dose, dose-rate and irradiation time simultaneously to predict the risk of low dose-rate irradiation. In this study, we analyzed quantitative relationship among dose, irradiation time and dose-rate, using chromosomal breakage and proliferation inhibition of human cells. For evaluation of chromosome breakage we assessed micronuclei induced by radiation. U2OS cells, a human osteosarcoma cell line, were exposed to gamma-ray in irradiation room bearing 50,000 Ci 60 Co. After the irradiation, they were cultured for 24 h in the presence of cytochalasin B to block cytokinesis, cytoplasm and nucleus were stained with DAPI and propidium iodide, and the number of binuclear cells bearing micronuclei was determined by fluorescent microscopy. For proliferation inhibition, cells were cultured for 48 h after the irradiation and [3H] thymidine was pulsed for 4 h before harvesting. Dose-rate in the irradiation room was measured with photoluminescence dosimeter. While irradiation time less than 24 h did not affect dose-response curves for both biological responses, they were remarkably attenuated as exposure time increased to more than 7 days. These biological responses were dependent on dose-rate rather than dose when cells were irradiated for 30 days. Moreover, percentage of micronucleus-forming cells cultured continuously for more than 60 days at the constant dose-rate, was gradually decreased in spite of the total dose accumulation. These results suggest that biological responses at low dose-rate, are remarkably affected by exposure time, that they are dependent on dose-rate rather than total dose in the case of long-term irradiation, and that cells are getting resistant to radiation after the continuous irradiation for 2 months. It is necessary to include effect of irradiation time and dose-rate sufficiently to evaluate risk

Whole-body dose meters. Measurements of total activity

International Nuclear Information System (INIS)

Koeppe, P.; Klinikum Steglitz, Berlin

1990-01-01

By means of measurements using a whole-body dose meter, the course of the incorporation of radionuclides was established between April 1986 and May 1989 for unchanged conditions of alimentation, activity-conscious alimentation, and uniquely increased incorporation. Monitoring covered persons from the most different spheres of life. The incorporation is compared with the one resulting from nuclear weapons explosions in the atmosphere. (DG) [de

Effect of low gamma ray doses on sugar beet

International Nuclear Information System (INIS)

Al-Oudat, M.

1993-01-01

We studied the effect of presowing irradiation simulation on sugar beet seeds in two regions (Deir Elzour and Damascus) and for three successive cropping seasons (1986-1989). Those seeds were irradiated with gamma radiation doses varying from 0.005 to 0.050 kGy in the first region, and from 0.005 to 0.025 kGy in the second region. Results showed that doses varying from 0.005 to 0.05 kGy in Deir Elzour gave a mean yield increase varying from 17.4% to 22.6%. However, doses varying from 0.005 to 0.025 in Damascus gave an increase of the same parameter between 19.5% and 23.8%. The best results for pure sugar yield increase obtained for a dose of 0.015 kGy (27.1% in Deir Elzour and 31.9% in Damascus). Yields on the farm level obtained from presowing irradiated seeds showed an increase in sugar beets when using 0.015 kGy gamma radiation dose. (author)

Factors influencing changes in levels of radiation doses received by patients during gastroduodenal series procedures in the Hospital Dr. Max Peralta de Cartago

International Nuclear Information System (INIS)

Guzman Campos, Jeremy; Vargas Navarro, Jonnathan

2009-01-01

A measurement was made of the number of radiation doses emitted by fluoroscopy equipment used in Hospital Dr. Max Peralta, specifically at the Centro de Deteccion de Cancer Gastrico. The analysis has included the factors could be influencing on increase of the total dose to the patient, by means of indicators that directly affect the unnecessary increase in dose, such as: the procedure, sequences of images, indicators of dosage levels, varying conditions of actual studies, variations dose levels and production process factors. [es

Iron Oxide Nanoparticle Agglomeration Influences Dose-Rates and Modulates Oxidative Stress Mediated Dose-Response Profiles In Vitro

Energy Technology Data Exchange (ETDEWEB)

Sharma, Gaurav; Kodali, Vamsi K.; Gaffrey, Matthew J.; Wang, Wei; Minard, Kevin R.; Karin, Norman J.; Teeguarden, Justin G.; Thrall, Brian D.

2013-07-31

Spontaneous agglomeration of engineered nanoparticles (ENPs) is a common problem in cell culture media which can confound interpretation of in vitro nanotoxicity studies. The authors created stable agglomerates of iron oxide nanoparticles (IONPs) in conventional culture medium, which varied in hydrodynamic size (276 nm-1.5 μm) but were composed of identical primary particles with similar surface potentials and protein coatings. Studies using C10 lung epithelial cells show that the dose rate effects of agglomeration can be substantial, varying by over an order of magnitude difference in cellular dose in some cases. Quantification by magnetic particle detection showed that small agglomerates of carboxylated IONPs induced greater cytotoxicity and redox-regulated gene expression when compared with large agglomerates on an equivalent total cellular IONP mass dose basis, whereas agglomerates of amine-modified IONPs failed to induce cytotoxicity or redox-regulated gene expression despite delivery of similar cellular doses. Dosimetry modelling and experimental measurements reveal that on a delivered surface area basis, large and small agglomerates of carboxylated IONPs have similar inherent potency for the generation of ROS, induction of stress-related genes and eventual cytotoxicity. The results suggest that reactive moieties on the agglomerate surface are more efficient in catalysing cellular ROS production than molecules buried within the agglomerate core. Because of the dynamic, size and density-dependent nature of ENP delivery to cells in vitro, the biological consequences of agglomeration are not discernible from static measures of exposure concentration (μg/ml) alone, highlighting the central importance of integrated physical characterisation and quantitative dosimetry for in vitro studies. The combined experimental and computational approach provides a quantitative framework for evaluating relationships between the biocompatibility of nanoparticles and their

Changes in radiation dose with variations in human anatomy: larger and smaller normal-stature adults.

Science.gov (United States)

Marine, Patrick M; Stabin, Michael G; Fernald, Michael J; Brill, Aaron B

2010-05-01

A systematic evaluation has been performed to study how specific absorbed fractions (SAFs) vary with changes in adult body size, for persons of different size but normal body stature. A review of the literature was performed to evaluate how individual organ sizes vary with changes in total body weight of normal-stature individuals. On the basis of this literature review, changes were made to our easily deformable reference adult male and female total-body models. Monte Carlo simulations of radiation transport were performed; SAFs for photons were generated for 10th, 25th, 75th, and 90th percentile adults; and comparisons were made to the reference (50th) percentile SAF values. Differences in SAFs for organs irradiating themselves were between 0.5% and 1.0%/kg difference in body weight, from 15% to 30% overall, for organs within the trunk. Differences in SAFs for organs outside the trunk were not greater than the uncertainties in the data and will not be important enough to change calculated doses. For organs irradiating other organs within the trunk, differences were significant, between 0.3% and 1.1%/kg, or about 8%-33% overall. The differences are interesting and can be used to estimate how different patients' dosimetry might vary from values reported in standard dose tables.

Dynamically accumulated dose and 4D accumulated dose for moving tumors

International Nuclear Information System (INIS)

Li Heng; Li Yupeng; Zhang Xiaodong; Li Xiaoqiang; Liu Wei; Gillin, Michael T.; Zhu, X. Ronald

2012-01-01

Purpose: The purpose of this work was to investigate the relationship between dynamically accumulated dose (dynamic dose) and 4D accumulated dose (4D dose) for irradiation of moving tumors, and to quantify the dose uncertainty induced by tumor motion. Methods: The authors established that regardless of treatment modality and delivery properties, the dynamic dose will converge to the 4D dose, instead of the 3D static dose, after multiple deliveries. The bounds of dynamic dose, or the maximum estimation error using 4D or static dose, were established for the 4D and static doses, respectively. Numerical simulations were performed (1) to prove the principle that for each phase, after multiple deliveries, the average number of deliveries for any given time converges to the total number of fractions (K) over the number of phases (N); (2) to investigate the dose difference between the 4D and dynamic doses as a function of the number of deliveries for deliveries of a “pulsed beam”; and (3) to investigate the dose difference between 4D dose and dynamic doses as a function of delivery time for deliveries of a “continuous beam.” A Poisson model was developed to estimate the mean dose error as a function of number of deliveries or delivered time for both pulsed beam and continuous beam. Results: The numerical simulations confirmed that the number of deliveries for each phase converges to K/N, assuming a random starting phase. Simulations for the pulsed beam and continuous beam also suggested that the dose error is a strong function of the number of deliveries and/or total deliver time and could be a function of the breathing cycle, depending on the mode of delivery. The Poisson model agrees well with the simulation. Conclusions: Dynamically accumulated dose will converge to the 4D accumulated dose after multiple deliveries, regardless of treatment modality. Bounds of the dynamic dose could be determined using quantities derived from 4D doses, and the mean dose

Absorbed dose thresholds and absorbed dose rate limitations for studies of electron radiation effects on polyetherimides

Science.gov (United States)

Long, Edward R., Jr.; Long, Sheila Ann T.; Gray, Stephanie L.; Collins, William D.

1989-01-01

The threshold values of total absorbed dose for causing changes in tensile properties of a polyetherimide film and the limitations of the absorbed dose rate for accelerated-exposure evaluation of the effects of electron radiation in geosynchronous orbit were studied. Total absorbed doses from 1 kGy to 100 MGy and absorbed dose rates from 0.01 MGy/hr to 100 MGy/hr were investigated, where 1 Gy equals 100 rads. Total doses less than 2.5 MGy did not significantly change the tensile properties of the film whereas doses higher than 2.5 MGy significantly reduced elongation-to-failure. There was no measurable effect of the dose rate on the tensile properties for accelerated electron exposures.

Total ionizing dose radiation hardness of the ATLAS MDT-ASD and the HP-Agilent 0.5 um CMOS process

CERN Document Server

Posch, C

2002-01-01

A total ionizing dose (TID) test of the MDT-ASD, the ATLAS MDT front-end chip has been performed at the Harvard Cyclotron Lab. The MDT-ASD is an 8-channel drift tube read-out ASIC fabricated in a commercial 0.5 um CMOS process (AMOS14TB). The accumulated TID at the end of the test was 300 krad, delivered by 160 MeV protons at a rate of approximately 70 rad/sec. All 10 irradiated chips retained their full functionality and performance and showed only irrelevantly small changes in device parameters. As the total accumulated dose is substantially higher than the relevant ATLAS Radiation Tolerance Criteria (RTCtid), the results of this test indicate that MDT-ASD meets the ATLAS TID radiation hardness requirements. In addition, the results of this test correspond well with results of a 30 keV gamma TID irradiation test performed by us on an earlier prototype at the CERN x-ray facility as well as with results of other irradiation test on this process found in literature.

Possible changes in the dose of biologically active ultraviolet radiation received by the biosphere in the summertime Arctic due to total ozone interannual variability

Energy Technology Data Exchange (ETDEWEB)

Gruzdev, Aleksandr N. (Institute of Atmospheric Physics, Russian Academy of Sciences, Moscow (Russian Federation))

1994-12-01

Data for total ozone measurements since 1972 from the world ozone measuring network have been analyzed to study ozone interannual variability and estimate its possible effect on the UV-B dose received by the arctic biosphere. Possible interannual changes in the UV-B dose received by DNA associated with overall interannual ozone variability, as well as with the quasi-biennial oscillation (QBO) in total ozone were computed for different summer months. In general, the largest interannual variations in UV-B dose may occur in the Russian Arctic, whereas the possible variations in the Canadian Arctic are the smallest. Overall variations in the UV-B dose received by DNA can exceed 25% (2[sigma] criterion) in the Taimyr and Severnaya Zemlya for June and July, and 30% in the Laptev Sea for August. In the European sector of the Arctic, the possible variations are greater than 10%, and can exceed 15% in the north Norwegian Sea for July and 20% in Spitsbergen for August. Possible overall variations in the Canadian Arctic and Alaska are [<=]10%, reaching 15% in Alaska for August, however. The total ozone QBO can also cause essential and (statistically) predicted changes in UV-B radiation. In general, the UV-B dose received by DNA is found to be greater in the Arctic during the westerly phase of the QBO of the equatorial stratospheric wind at 50 mb level than during the easterly phase. The difference can reach or exceed 15% (relative to the mean value) in Taimyr for June and in Severnaya Zemlya for July and August. In northern Europe and Iceland, the difference can reach 10% for August. In the Canadian Arctic, the QBO-related effect is small. In Alaska, the appropriate difference in UV-B dose has an opposite sign for August, exceeding 5% in magnitude

Unscheduled DNA synthesis in spleen cells of mice exposed to low doses of total body irradiation

International Nuclear Information System (INIS)

Tuschl, H.; Kovac, R.; Hruby, E.

1983-07-01

Unscheduled DNA synthesis was induced by UV irradiation of spleen cells obtained from C 57 Bl mice after repeated total body irradiation of 0.05 Gy 60 Co (0.00125 Gy/mice) and determined autoradiographically. An enhancement in the ability for repair of UV induced DNA lesions was observed in cells of gamma irradiated animals. While the amount of 3 H-thymidine incorporated per cell was increased, the percentage of labeled cells remained unchanged. The present results are compared with previous data on low dose radiation exposure in men. (Author) [de

Effects of varying the longitudinal dispersion and no drip cask rate failures upon Yucca Mountain site performance

International Nuclear Information System (INIS)

Winterle, Bret

2001-01-01

Proposed changes in the regulatory time limits used for viability assessments of the proposed national high-level radioactive waste repository in Yucca Mountain, Nevada from 10,000 years to 100,000 or even 1,000,000 years call into question both the modelling techniques used to represent the repository's long-term performance, and our ability to extrapolate technological, climatological and geological phenomenon. Using a high-powered risk-assessment software program called Goldsim that a simplified total system performance assessment (STSPA) was designed for, the effects of varying the performance parameters of two barrier systems, one natural and one man-made, upon the total system performance were observed. The conclusion reached by varying these two parameters is that for a regulatory guideline of 10,000 years, there is no noticeable effect on the total system performance, but at 300,000 years, it appears that the effect of reducing the longitudinal dispersion rate (a natural barrier) by one order of magnitude produced an astronomically high receptor dose, indicating that as predicted, our abilities to model situations beyond our ability to accurately extrapolate current scientific research is futile. (author)

Effects of varying the longitudinal dispersion and no drip cask rate failures upon Yucca Mountain site performance

Energy Technology Data Exchange (ETDEWEB)

Winterle, Bret

2001-07-01

Proposed changes in the regulatory time limits used for viability assessments of the proposed national high-level radioactive waste repository in Yucca Mountain, Nevada from 10,000 years to 100,000 or even 1,000,000 years call into question both the modelling techniques used to represent the repository's long-term performance, and our ability to extrapolate technological, climatological and geological phenomenon. Using a high-powered risk-assessment software program called Goldsim that a simplified total system performance assessment (STSPA) was designed for, the effects of varying the performance parameters of two barrier systems, one natural and one man-made, upon the total system performance were observed. The conclusion reached by varying these two parameters is that for a regulatory guideline of 10,000 years, there is no noticeable effect on the total system performance, but at 300,000 years, it appears that the effect of reducing the longitudinal dispersion rate (a natural barrier) by one order of magnitude produced an astronomically high receptor dose, indicating that as predicted, our abilities to model situations beyond our ability to accurately extrapolate current scientific research is futile. (author)

Effects of varying doses of β-nerve growth factor on the timing of ovulation, plasma progesterone concentration and corpus luteum size in female alpacas (Vicugna pacos).

Science.gov (United States)

Stuart, C C; Vaughan, J L; Kershaw-Young, C M; Wilkinson, J; Bathgate, R; de Graaf, S P

2015-11-01

Ovulation in camelids is induced by the seminal plasma protein ovulation-inducing factor (OIF), recently identified as β-nerve growth factor (β-NGF). The present study measured the total protein concentration in alpaca seminal plasma using a bicinchoninic acid (BCA) protein quantification assay and found it to be 22.2±2.0mgmL(-1). To measure the effects of varying doses of β-NGF on the incidence and timing of ovulation, corpus luteum (CL) size and plasma progesterone concentration, 24 female alpacas were synchronised and treated with either: (1) 1mL 0.9% saline (n=5); (2) 4µg buserelin (n=5); (3) 1mg β-NGF protein (n=5); (4) 0.1mg β-NGF (n=5); or (5) 0.01mg β-NGF (n=4). Females were examined by transrectal ultrasonography at 1-2-h intervals between 20 and 45h after treatment or until ovulation occurred, as well as on Day 8 to observe the size of the CL, at which time blood was collected to measure plasma progesterone concentrations. Ovulation was detected in 0/5, 5/5, 5/5, 3/5 and 0/4 female alpacas treated with saline, buserelin, 1, 0.1 and 0.01mg β-NGF, respectively. Mean ovulation interval (P=0.76), CL diameter (P=0.96) and plasma progesterone concentration (P=0.96) did not differ between treatments. Mean ovulation interval overall was 26.2±1.0h. In conclusion, buserelin and 1mg β-NGF are equally effective at inducing ovulation in female alpacas, but at doses ≤0.1mg, β-NGF is not a reliable method for the induction of ovulation.

85Kr management trade-offs: a perspective to total radiation dose commitment

International Nuclear Information System (INIS)

Mellinger, P.J.; Hoenes, G.R.; Brackenbush, L.W.; Greenborg, J.

1980-01-01

Radiological consequences arising from the trade-offs for 85 Kr waste management from possible nuclear fuel resource recovery activities have been investigated. The reference management technique is to release all the waste gas to the atmosphere where it is diluted and dispersed. A potential alternative is to collect, concentrate, package and submit the gas to long-term storage. This study compares the radiation dose commitment to the public and to the occupationally exposed work force from these alternatives. The results indicate that it makes little difference to the magnitude of the world population dose whether 85 Kr is captured and stored or chronically released to the environment. Further, comparisons of radiation exposures (for the purpose of estimating health effects) at very low dose rates to very large populations with exposures to a small number of occupationally exposed workers who each receive much higher dose rates may be misleading. Finally, cost studies (EPA 1976 and DOE 1979a) show that inordinate amounts of money will be required to lower this already extremely small 80-year cumulative world population dose of 0.05 mrem/person

SU-F-T-327: Total Body Irradiation In-Vivo Dose Measurements Using Optically Stimulated Luminescence (OSL) NanoDots and Farmer Type Ion Chamber

International Nuclear Information System (INIS)

Kaur, H; Kumar, S; Sarkar, B; Ganesh, T; Giri, U; Jassal, K; Rathinamuthu, S; Gulia, G; Gopal, V; Mohanti, B; Munshi, A

2016-01-01

Purpose: This study was performed to analyze the agreement between optically stimulated luminescence (OSL) nanoDots measured doses and 0.6 cc Farmer type ionization chamber measured doses during total body irradiation (TBI). Methods: In-vivo dose measurements using OSL nanoDots and Farmer chamber were done in a total of twelve patients who received TBI at our center by bilateral parallel-opposed beams technique. In this technique, the patient is kept inside the TBI box which is filled with rice bags and irradiated using two bilateral parallel opposed beams of 40×40 cm"2 size with 45° collimator rotation at an SSD of 333.5 cm in an Elekta Synergy linear accelerator. All patients received a dose of 2 Gy in single fraction as conditioning regimen. The beams were equally weighted at the midplane of the box. The nanoDots were placed over forehead, right and left neck, right and left lung, umbilicus, right and left abdomen, medial part of thigh, knee and toe. A 0.6 cc Farmer chamber was placed in between the thighs of the patient. Measured doses are reported along with the statistical comparisons using paired sample t-test. Results: For the above sites the mean doses were 212.2±21.1, 218.2±7.6, 218.7±9.3, 215.6±9.5, 217.5±11.5, 214.5±7.7, 218.3±6.8, 221.5±15, 229.1±11.0, 220.5±7.7 and 223.3±5.1 cGy respectively. For all OSL measurements the mean dose was 218.6±11.8 cGy. Farmer chamber measurements yielded a mean dose of 208.8±15.6 cGy. Statistical analysis revealed that there was no significant difference between OSL measured doses in forehead, right and left neck, right and left lung, umbilicus, right and left abdomen and toe and Farmer chamber measured doses (0.72≤p≤0.06). However the mean OSL doses at thigh and knee were statistically different (p<0.05) from the Farmer chamber measurements. Conclusion: OSL measurements were found to be in agreement with Farmer type ionization chamber measurements in in-vivo dosimetry of TBI.

Effective doses to patients undergoing thoracic computed tomography examinations.

Science.gov (United States)

Huda, W; Scalzetti, E M; Roskopf, M

2000-05-01

The purpose of this study was to investigate how x-ray technique factors and effective doses vary with patient size in chest CT examinations. Technique factors (kVp, mAs, section thickness, and number of sections) were recorded for 44 patients who underwent a routine chest CT examination. Patient weights were recorded together with dimensions and mean Hounsfield unit values obtained from representative axial CT images. The total mass of directly irradiated patient was modeled as a cylinder of water to permit the computation of the mean patient dose and total energy imparted for each chest CT examination. Computed values of energy imparted during the chest CT examination were converted into effective doses taking into account the patient weight. Patient weights ranged from 4.5 to 127 kg, and half the patients in this study were children under 18 years of age. All scans were performed at 120 kVp with a 1 s scan time. The selected tube current showed no correlation with patient weight (r2=0.06), indicating that chest CT examination protocols do not take into account for the size of the patient. Energy imparted increased with increasing patient weight, with values of energy imparted for 10 and 70 kg patients being 85 and 310 mJ, respectively. The effective dose showed an inverse correlation with increasing patient weight, however, with values of effective dose for 10 and 70 kg patients being 9.6 and 5.4 mSv, respectively. Current CT technique factors (kVp/mAs) used to perform chest CT examinations result in relatively high patient doses, which could be reduced by adjusting technique factors based on patient size.

A trial of radiation dose prescription based on dose-cell survival formula

International Nuclear Information System (INIS)

Allen, E.P.

1984-01-01

Radiation treatment has been prescribed for 379 basal cell carcinomata on the basis of a selected equivalent single dose derived from the standard multi-target dose-cell survival formula using values of m = 2 and Do = 130 rads for orthovoltage x-rays. The results suggest that the approach provides a flexible and acceptable alternative to prescription by total dose or by Nominal Standard Dose. It is submitted that Total Dose is an inadequate expression of radiobiological effects: that the NSD and related systems are valuable measures of the ability of normal tissues to recover from radiation damage: and that a parallel measure of the degree of tumour depopulation has become necessary to allow further progress in alternative fractionation schedules

Total dose behavior of partially depleted SOI dynamic threshold voltage MOS (DTMOS) for very low supply voltage applications (0.6 - 1 V)

International Nuclear Information System (INIS)

Ferlet-Cavrois, V.; Musseau, O.; Leray, J.L.; Faynot, O.; Raynaud, C.; Pelloie, J.L.

1999-01-01

In this paper, we presented two DTMOS architectures processed with a partially depleted SOI technology. The first architecture, DTMOS without limiting transistor, is dedicated to ultra-low voltage applications, at 0.6 V. For 1V applications, the second architecture, DTMOS with limiting transistor, needs an additional transistor to limit the body-source diode current. The total dose irradiation of both DTMOS architectures induces no change of the drain current, but an increase of the body-source diode current. Total dose induced trapped charge in the buried oxide increases the body potential of the DTMOS transistor. It induces an increase of the current flow at the back interface of the silicon film. Irradiation of complex circuits using DTMOS transistors would lead to a degradation of the stand-by consumption. (authors)

Increased mortality by septicemia, interstitial pneumonitis and pulmonary fibrosis among bone marrow transplant recipients receiving an increased mean dose rate of total irradiation

International Nuclear Information System (INIS)

Ringden, O.; Baaryd, I.; Johansson, B.

1983-01-01

Seven bone marrow transplant recipients with acute lymphoblastic leukemia receiving a mean dose rate of 0.07 Gy/min of total body irradiation towards the pelvic midpoint and the lungs had an increased (p<0.01) overall death rate of 86 per cent compared with 33 per cent among 27 patients with acute non-lymphoblastic leukemia or acute lymphoblastic leukemia treated with a mean dose rate of 0.04 Gy/min. Among the patients receiving the higher dose rate there was an increased mortality in causes related to radiation toxicity like early septicemia, interstitial pneumonitis and pulmonary fibrosis, compared with all patients receiving the lower dose rate (p<0.01) and also with 10 patients from this group with acute lymphoblastic leukemia (p<0.02). (Auth.)

Total dose and dose-rate effects on start-up current in anti-fuse FPGA

International Nuclear Information System (INIS)

Wang, J.; Wong, W.; McCollum, J.; Cronquist, B.; Katz, R.; Kleyner, I.; Kleyner, F.

1999-01-01

Radiation enhanced start-up current (RESC) in an anti-fuse FPGA, A1280A, is thoroughly investigated and a comprehensive transistor-level mechanism is proposed. Low dose-rate testing, appropriate for civilian space applications, and annealing at room temperature shows RESC to be negligible for the lot of parts tested with a fixed power supply slew rate. (authors)

85Kr management trade-offs: a perspective to total radiation dose commitment

Energy Technology Data Exchange (ETDEWEB)

Mellinger, P.J.; Hoenes, G.R.; Brackenbush, L.W.; Greenborg, J.

1980-01-01

Radiological consequences arising from the trade-offs for /sup 85/Kr waste management from possible nuclear fuel resource recovery activities have been investigated. The reference management technique is to release all the waste gas to the atmosphere where it is diluted and dispersed. A potential alternative is to collect, concentrate, package and submit the gas to long-term storage. This study compares the radiation dose commitment to the public and to the occupationally exposed work force from these alternatives. The results indicate that it makes little difference to the magnitude of the world population dose whether /sup 85/Kr is captured and stored or chronically released to the environment. Further, comparisons of radiation exposures (for the purpose of estimating health effects) at very low dose rates to very large populations with exposures to a small number of occupationally exposed workers who each receive much higher dose rates may be misleading. Finally, cost studies (EPA 1976 and DOE 1979a) show that inordinate amounts of money will be required to lower this already extremely small 80-year cumulative world population dose of 0.05 mrem/person (<0.001% of natural background radiation for the same time period).

Low-dose CT imaging of a total hip arthroplasty phantom using model-based iterative reconstruction and orthopedic metal artifact reduction

Energy Technology Data Exchange (ETDEWEB)

Wellenberg, R.H.H.; Streekstra, G.J.; Maas, M. [Academic Medical Center, Department of Radiology, Amsterdam (Netherlands); Boomsma, M.F.; Osch, J.A.C. van [Department of Radiology, Zwolle (Netherlands); Vlassenbroek, A. [Philips Medical Systems, Brussels (Belgium); Milles, J. [Philips Medical Systems, Eindhoven (Netherlands); Edens, M.A. [Department of Innovation and Science, Zwolle (Netherlands); Slump, C.H. [University of Twente, MIRA Institute for Biomedical Technology and Technical Medicine, Enschede (Netherlands)

2017-05-15

To compare quantitative measures of image quality, in terms of CT number accuracy, noise, signal-to-noise-ratios (SNRs), and contrast-to-noise ratios (CNRs), at different dose levels with filtered-back-projection (FBP), iterative reconstruction (IR), and model-based iterative reconstruction (MBIR) alone and in combination with orthopedic metal artifact reduction (O-MAR) in a total hip arthroplasty (THA) phantom. Scans were acquired from high- to low-dose (CTDI{sub vol}: 40.0, 32.0, 24.0, 16.0, 8.0, and 4.0 mGy) at 120- and 140- kVp. Images were reconstructed using FBP, IR (iDose{sup 4} level 2, 4, and 6) and MBIR (IMR, level 1, 2, and 3) with and without O-MAR. CT number accuracy in Hounsfield Units (HU), noise or standard deviation, SNRs, and CNRs were analyzed. The IMR technique showed lower noise levels (p < 0.01), higher SNRs (p < 0.001) and CNRs (p < 0.001) compared with FBP and iDose{sup 4} in all acquisitions from high- to low-dose with constant CT numbers. O-MAR reduced noise (p < 0.01) and improved SNRs (p < 0.01) and CNRs (p < 0.001) while improving CT number accuracy only at a low dose. At the low dose of 4.0 mGy, IMR level 1, 2, and 3 showed 83%, 89%, and 95% lower noise values, a factor 6.0, 9.2, and 17.9 higher SNRs, and 5.7, 8.8, and 18.2 higher CNRs compared with FBP respectively. Based on quantitative analysis of CT number accuracy, noise values, SNRs, and CNRs, we conclude that the combined use of IMR and O-MAR enables a reduction in radiation dose of 83% compared with FBP and iDose{sup 4} in the CT imaging of a THA phantom. (orig.)

The role of total dose in conservative surgery and radiation therapy for early stage breast cancer: is there a critical level?

Energy Technology Data Exchange (ETDEWEB)

White, Julia; Brown, Douglas; Gustafson, Greg; Chen, Peter; Matter, Richard; Cook, Carla; Martinez, Alvaro; Vicini, Frank A

1995-07-01

Purpose: Over the past several years, it has been our standard policy after breast conserving surgery to treat the entire breast to 45-50 Gy followed by a supplemental boost dose to the tumor bed to a minimum of 60 Gy with standard fractionation. We reviewed patients who received < 60 Gy to the tumor bed to identify any differences in recurrence rates in the breast. Materials and Methods: From 1/1/75 through 12/31/87, 443 consecutive patients diagnosed with stage I and II breast cancer (unilateral) were treated with conservative surgery and radiation therapy (CSRT) at William Beaumont Hospital. All patients underwent at least an excisional biopsy and 268 (60%) patients were re-excised. An ipsilateral axillary lymph node dissection was performed on 420 patients (95%). All patients received whole breast irradiation to 45-50 Gy. A supplemental boost dose was delivered to the tumor bed with either an implant, electrons, or photons in 404 (91%) patients. Median follow-up of surviving patients is 88 months. Results: Thirty-three patients of the 443 have suffered a failure in the treated breast for a 5 and 10 yr actuarial rate of local recurrence of 5 and 10%, respectively. Evaluation by total dose to the tumor bed is as follows: The distribution of patient's respective histology, tumor size, hormonal status, age, re-excision status, and adjuvant systemic therapy was similar among the dose groups. On multivariate analysis (Cox), in addition to total dose to tumor bed (p=0.002), the only other factor which was significantly associated with local recurrence was patient age {<=} 35 (p=0.002). Conclusions: Patients who receive {<=} 50 Gy to the tumor bed without careful attention to excisional status are at a significantly higher risk of local failure. This underlies the importance of supplementing the tumor bed dose after whole breast radiation therapy in those patients whose status of excision is not definitely known.

Patterns of dose variability in radiation prescription of breast cancer

International Nuclear Information System (INIS)

Das, Indra J.; Chee-Wai, Cheng; Fein, Douglas A.; Fowble, Barbara

1995-01-01

magnitudes of 5-10%, 10-15% and >15% were noted among 55%, 40%, and 50% of the patients, respectively. The average photon prescription dose in our institution at the 1.5 cm point was 46.9±1.7 Gy. The average doses for the small, medium, and large breast, relative to the reference point are shown in Table 1. Except for the magnitude of the hot spot, the dose values at various prescription points are independent of the breast size. Conclusions: Our study showed that there is a wide variation of prescribed dose among the different protocols commonly used in breast irradiation. For 90% of the patient population, the dose prescription is obtained within ±1% whether the prescription point was chosen at (h(3)) or at the lung-chest wall interface. On the other hand, the average dose variation is about ± 3% among the protocols with dose prescription point varying between the reference point and the (h(2)) point. With the prescription at the isocenter, an average variation of 4-5% was observed. However, deviation up to 11% were noted for some patients. The maximum dose inhomogeneity for such patients was significantly higher up to +27% even without the lung correction. A typical dose in tangential field irradiation is in the range of 46-50 Gy with a fraction size of 1.8-2.0 Gy. The results of our study indicate that the prescription dose may vary between 5.0-5.5 Gy and hot spot in the range of 2.3-2.5 Gy/fraction depending on the protocol and breast size. Thus when the chest wall separation is > 22 cm, a high energy beam is advised to reduce the dose inhomogeneity. Dose specification at the isocenter should be discouraged unless the total dose to the breast is modified

Intraoperative low-dose ketamine infusion reduces acute postoperative pain following total knee replacement surgery: a prospective, randomized double-blind placebo-controlled trial.

Science.gov (United States)

Cengiz, Pelin; Gokcinar, Derya; Karabeyoglu, Isil; Topcu, Hulya; Cicek, Gizem Selen; Gogus, Nermin

2014-05-01

To evaluate the effect of intraoperative low-dose ketamine with general anesthesia on postoperative pain after total knee replacement surgery. A randomized, double-blind comparative study. Ankara Numune Training and Research Hospital, Turkey, from January and June 2011. Sixty adults undergoing total knee arthroplasty were enrolled in this study. The patients were randomly allocated into two groups of equal size to receive either racemic ketamine infusion (6 μg/kg/minute) or the same volume of saline. A visual analogue scale (VAS) was used to measure each patient's level of pain at 1, 3, 6, 12, and 24 hours after surgery. Time to first analgesic request, postoperative morphine consumption and the incidence of side effects were also recorded. Low-dose ketamine infusion prolonged the time to first analgesic request. It also reduced postoperative cumulative morphine consumption at 1, 3, 6, 12, and 24 hours postsurgery (p < 0.001). Postoperative VAS scores were also significantly lower in the ketamine group than placebo, at all observation times. Incidences of side effects were similar in both study groups. Intraoperative continuous low-dose ketamine infusion reduced pain and postoperative analgesic consumption without affecting the incidence of side effects.

Radiation dose to technologists per nuclear medicine examination and estimation of annual dose.

Science.gov (United States)

Bayram, Tuncay; Yilmaz, A Hakan; Demir, Mustafa; Sonmez, Bircan

2011-03-01

Conventional diagnostic nuclear medicine applications have been continuously increasing in most nuclear medicine departments in Turkey, but to our knowledge no one has studied the doses to technologists who perform nuclear medicine procedures. Most nuclear medicine laboratories do not have separate control rooms for technologists, who are quite close to the patient during data acquisition. Technologists must therefore stay behind lead shields while performing their task if they are to reduce the radiation dose received. The aim of this study was to determine external radiation doses to technologists during nuclear medicine procedures with and without a lead shield. Another aim was to investigate the occupational annual external radiation doses to Turkish technologists. This study used a Geiger-Müller detector to measure dose rates to technologists at various distances from patients (0.25, 0.50, 1, and 2 m and behind a lead shield) and determined the average time spent by technologists at these distances. Deep-dose equivalents to technologists were obtained. The following conventional nuclear medicine procedures were considered: thyroid scintigraphy performed using (99m)Tc pertechnetate, whole-body bone scanning performed using (99m)Tc-methylene diphosphonate, myocardial perfusion scanning performed using (99m)Tc-methoxyisobutyl isonitrile, and (201)Tl (thallous chloride) and renal scanning performed using (99m)Tc-dimercaptosuccinic acid. The measured deep-dose equivalent to technologists per procedure was within the range of 0.13 ± 0.05 to 0.43 ± 0.17 μSv using a lead shield and 0.21 ± 0.07 to 1.01 ± 0.46 μSv without a lead shield. Also, the annual individual dose to a technologist performing only a particular scintigraphic procedure throughout a year was estimated. For a total of 95 clinical cases (71 patients), effective external radiation doses to technologists were found to be within the permissible levels. This study showed that a 2-mm lead shield

Radiological Evaluation of the effects of varied doses of Celecoxib on fracture healing in dogs

Directory of Open Access Journals (Sweden)

Edwin Aihanuwa Uwagie-Ero and Rapheal Chukwujekwu Kene

2011-04-01

Full Text Available To determine if Cyclooxygenase -2 (COX-2 functions in fracture healing, 10 dogs were treated with COX-2-selective nonsteroidal anti-inflammatory drugs (Celecoxib to reduce and stop COX-2-dependent prostaglandin production. Radiographic testing evaluation determined that fracture healing was not affected in dogs treated with a low dose of COX-2-selective NSAIDs (celecoxib and delayed union was observed in dogs treated with a high dose of COX-2-selective NSAIDs (celecoxib. Celecoxib dose of 5 mg/kg/day did not affect fracture callus formed in the study group and did not cause a significant increase in the proportion of delayed unions, however, at a dose of 10 mg/kg/day it reduced the rate of fracture callus formation and significantly increased the proportion of delayed unions for dogs in the group. [Veterinary World 2011; 4(2.000: 75-76

Combined use of low dose gamma irradiation and fenoxycarb, as a means of protection against infestation of wheat grains with khapra beetle Trogoderma granarium, Everts

International Nuclear Information System (INIS)

Ghanem, I; Al-Ek, H.

2006-04-01

Larvae of khapra beetle were exposed to one of the following treatments: Rearing on wheat grains treated with varying concentrations of fenoxycarb. Irradiation with varying doses of gamma rays followed by rearing on non-treated wheat grains. Irradiation with varying doses of gamma rays followed by rearing on fenoxycarb-treated wheat grains. The development of these larvae was followed and the percentage of each developmental stage was recorded. Results indicate that the combined use of radiation and fenoxycarb resulted in a accumulative effect that leads to the reduction in the doses of both treatments needed to achieve a complete abolition of adult emergence. Within five weeks of commencement about 85% of the larvae in the control treatment have reached adulthood, eggs laid by these adults have hatched into life larvae. When larvae were irradiated with gamma ray, development was disrupted and percentages of emerging adults decreased with the increase in irradiation dose. At a dose of 100 Gy adult emergence was abolished and no adults were found five weeks from the start of the experiment. Likewise, Rearing of larvae on fenoxycarb-treated grains resulted in a disruption of development and a dose of 1ppm was necessary to achieve total abolishment of adult emergence. However, when a combination of gamma ray and fenoxycarb treatment was applied a accumulative effect was observed resulting in a reduction in the doses of irradiation and fenoxycarb needed to achieve similar results. The doses needed to achieve a total absence of adult emergence were reduced to 50Gy and 0.063 ppm for irradiation and fenoxycarb treatment respectively. The significance of the above results is discussed, and an explanation to the observed accumulative effect is offered. (author)

Assessment of patient dose and radiogenic risks during endoscopic retrograde cholangiopancreatography

Energy Technology Data Exchange (ETDEWEB)

Sulieman, A.; Elzaki, M. [Sudan University of Science and Technology, College of Medical Radiologic Science, P. O. Box 1908, Khartoum 11111 (Sudan); Alkhorayef, M.; Babikir, E. [King Saud University, College of Applied Sciences, Radiological Sciences Department, P. O. Box 10219, Riyadh 11433 (Saudi Arabia); Abuzaid, M. [University of Sharjah, College of Health Sciences, Medical Diagnostic Imaging Department, Sharjah (United Arab Emirates); Dalton, A.; Bradley, D., E-mail: Abdelmoneim_a@yahoo.com [University of Surrey, Centre for Nuclear and Radiation Physics, Department of Physics, GU2-7XH, Guildford, Surrey (United Kingdom)

2015-10-15

Endoscopic retrograde cholangiopancreatography (ERCP) is an invasive technique that has been used for over 30 years in the diagnosis and management of pancreaticobiliary disorders. The objectives of this study were to evaluate the patient entrance surface air kerma doses (ESAK) and estimate the organ and effective doses during ERCP in three hospitals in Khartoum. A total of 55 patients were examined in three hospitals in Khartoum state, Sudan. Calibrated thermoluminescence dosimeters (TLD)-Gr-200-A)) were used to measure patients ESAK. The overall mean of ESAK for all ERCP procedures was 42.4 mGy. The mean patient ESAK in Fedail, Soba and Ibn sena centers were 26.7 mGy, 26.0 mGy, 72.4 mGy, respectively. The effective doses in three centers were 1.6, 1.56 and 2.67 mSv in that order and the overall mean effective dose was 2.01 mSv. Patient radiation doses vary widely among the different hospitals. Patient ESAK is low compared to previous studies in the light of the current practice. Patient dose was decreased significantly in the last two decades. (Author)

Assessment of patient dose and radiogenic risks during endoscopic retrograde cholangiopancreatography

International Nuclear Information System (INIS)

Sulieman, A.; Elzaki, M.; Alkhorayef, M.; Babikir, E.; Abuzaid, M.; Dalton, A.; Bradley, D.

2015-10-01

Endoscopic retrograde cholangiopancreatography (ERCP) is an invasive technique that has been used for over 30 years in the diagnosis and management of pancreaticobiliary disorders. The objectives of this study were to evaluate the patient entrance surface air kerma doses (ESAK) and estimate the organ and effective doses during ERCP in three hospitals in Khartoum. A total of 55 patients were examined in three hospitals in Khartoum state, Sudan. Calibrated thermoluminescence dosimeters (TLD)-Gr-200-A)) were used to measure patients ESAK. The overall mean of ESAK for all ERCP procedures was 42.4 mGy. The mean patient ESAK in Fedail, Soba and Ibn sena centers were 26.7 mGy, 26.0 mGy, 72.4 mGy, respectively. The effective doses in three centers were 1.6, 1.56 and 2.67 mSv in that order and the overall mean effective dose was 2.01 mSv. Patient radiation doses vary widely among the different hospitals. Patient ESAK is low compared to previous studies in the light of the current practice. Patient dose was decreased significantly in the last two decades. (Author)

Ionizing Radiation Effects on the Noise of 65 nm CMOS Transistors for Pixel Sensor Readout at Extreme Total Dose Levels

CERN Document Server

Re, V.; Manghisoni, M.; Riceputi, E.; Traversi, G.; Ratti, L.

2018-01-01

This paper is focused on the study of the noise performance of 65 nm CMOS transistors at extremely high total ionizing dose (TID) levels of the order of several hundreds of Mrad(SiO2). Noise measurements are reported and discussed, analyzing radiation effects on 1/ f noise and channel thermal noise. In nMOSFETs, up to 10 Mrad(SiO2), the experimental behavior is consistent with a damage mechanism mainly associ- ated with lateral isolation oxides, and can be modeled by parasitic transistors turning on after irradiation and contributing to the total noise of the device. At very high dose, these parasitic transistors tend to be turned off by negative charge accumulating in interface states and compensating radiation-induced positive charge building up inside thick isolation oxides. Effects associated with ionization and hydrogen transport in spacer oxides may become dominant at 600 Mrad(SiO2) and may explain the observed noise behavior at extremely high TID. The results of this analysis provide an understanding o...

A method comparison of total and HMW adiponectin : HMW/total adiponectin ratio varies versus total adiponectin, independent of clinical condition

NARCIS (Netherlands)

van Andel, Merel; Drent, Madeleine L; van Herwaarden, Antonius E; Ackermans, Mariëtte T; Heijboer, Annemieke C

BACKGROUND: Total and high-molecular-weight (HMW) adiponectin have been associated with endocrine and cardiovascular pathology. As no gold standard is available, the discussion about biological relevance of isoforms is complicated. In our study we perform a method comparison between two commercially

A method comparison of total and HMW adiponectin: HMW/total adiponectin ratio varies versus total adiponectin, independent of clinical condition

NARCIS (Netherlands)

van Andel, Merel; Drent, Madeleine L.; van Herwaarden, Antonius E.; Ackermans, Mariëtte T.; Heijboer, Annemieke C.

2017-01-01

Background: Total and high-molecular-weight (HMW) adiponectin have been associated with endocrine and cardiovascular pathology. As no gold standard is available, the discussion about biological relevance of isoforms is complicated. In our study we perform a method comparison between two commercially

Characterization of total ionizing dose damage in COTS pinned photodiode CMOS image sensors

Energy Technology Data Exchange (ETDEWEB)

Wang, Zujun, E-mail: wangzujun@nint.ac.cn; Ma, Wuying; Huang, Shaoyan; Yao, Zhibin; Liu, Minbo; He, Baoping; Sheng, Jiangkun; Xue, Yuan [State Key Laboratory of Intense Pulsed Radiation Simulation and Effect, Northwest Institute of Nuclear Technology, P.O.Box 69-10, Xi’an, Shaanxi 710024 (China); Liu, Jing [School of Materials Science and Engineering, Xiangtan University, Hunan (China)

2016-03-15

The characterization of total ionizing dose (TID) damage in COTS pinned photodiode (PPD) CMOS image sensors (CISs) is investigated. The radiation experiments are carried out at a {sup 60}Co γ-ray source. The CISs are produced by 0.18-μm CMOS technology and the pixel architecture is 8T global shutter pixel with correlated double sampling (CDS) based on a 4T PPD front end. The parameters of CISs such as temporal domain, spatial domain, and spectral domain are measured at the CIS test system as the EMVA 1288 standard before and after irradiation. The dark current, random noise, dark signal non-uniformity (DSNU), photo response non-uniformity (PRNU), overall system gain, saturation output, dynamic range (DR), signal to noise ratio (SNR), quantum efficiency (QE), and responsivity versus the TID are reported. The behaviors of the tested CISs show remarkable degradations after radiation. The degradation mechanisms of CISs induced by TID damage are also analyzed.

Impact of Drug Therapy, Radiation Dose, and Dose Rate on Renal Toxicity Following Bone Marrow Transplantation

International Nuclear Information System (INIS)

Cheng, Jonathan C.; Schultheiss, Timothy E.; Wong, Jeffrey Y.C.

2008-01-01

Purpose: To demonstrate a radiation dose response and to determine the dosimetric and chemotherapeutic factors that influence the incidence of late renal toxicity following total body irradiation (TBI). Methods and Materials: A comprehensive retrospective review was performed of articles reporting late renal toxicity, along with renal dose, fractionation, dose rate, chemotherapy regimens, and potential nephrotoxic agents. In the final analysis, 12 articles (n = 1,108 patients), consisting of 24 distinct TBI/chemotherapy conditioning regimens were included. Regimens were divided into three subgroups: adults (age ≥18 years), children (age <18 years), and mixed population (both adults and children). Multivariate logistic regression was performed to identify dosimetric and chemotherapeutic factors significantly associated with late renal complications. Results: Individual analysis was performed on each population subgroup. For the purely adult population, the only significant variable was total dose. For the mixed population, the significant variables included total dose, dose rate, and the use of fludarabine. For the pediatric population, only the use of cyclosporin or teniposide was significant; no dose response was noted. A logistic model was generated with the exclusion of the pediatric population because of its lack of dose response. This model yielded the following significant variables: total dose, dose rate, and number of fractions. Conclusion: A dose response for renal damage after TBI was identified. Fractionation and low dose rates are factors to consider when delivering TBI to patients undergoing bone marrow transplantation. Drug therapy also has a major impact on kidney function and can modify the dose-response function

Radiation therapy in the management of symptomatic bone metastases: the effect of total dose and histology on pain relief and response duration

International Nuclear Information System (INIS)

Arcangeli, Giorgio; Giovinazzo, Giuseppe; Saracino, Biancamaria; D'Angelo, Luciano; Giannarelli, Diana; Arcangeli, Giancarlo; Micheli, Adriana

1998-01-01

the several ranges of total dose delivered to the painful metastases, with 81%, 65%, and 46% complete relief rates in the 40-46 Gy, 30-36 Gy (p 0.03), and 8-28 Gy (p = 0.0001) dose ranges respectively. A straight correlation between total dose and complete pain relief was confirmed by the curve calculated by the logistic model which shows that doses of 30 Gy or more are necessary to achieve complete pain relief in 70% or more of bone metastases. This correlation holds also for the duration of pain control, as shown by the actuarial analysis of time to pain progression. Multivariate analyses, with complete pain relief and time to pain progression as endpoints show a highly significant effect of radiation dose (p = 0.0007) and performance status (p = 0.003), with lower rates of complete pain relief and shorter time to pain progression observed after smaller radiation total doses or higher Eastern Cooperative Oncology Group (ECOG) scores. Conclusion: Although single-dose or short course irradiation is an attractive treatment in reducing the number of multiple visits to radiotherapy departments for patients with painful bone metastases, it is nevertheless clear that aggressive protracted treatments seem to offer significant advantages especially for patients in whom the expected life span is not short

Towards a new dose and dose-rate effectiveness factor (DDREF)? Some comments.

Science.gov (United States)

Chadwick, K H

2017-06-26

The aim of this article is to offer a broader, mechanism-based, analytical tool than that used by (Rühm et al 2016 Ann. ICRP 45 262-79) for the interpretation of cancer induction relationships. The article explains the limitations of this broader analytical tool and the implications of its use in view of the publications by Leuraud et al 2015 (Lancet Haematol. 2 e276-81) and Richardson et al 2015 (Br. Med. J. 351 h5359). The publication by Rühm et al 2016 (Ann. ICRP 45 262-79), which is clearly work in progress, reviews the current status of the dose and dose-rate effectiveness factor (DDREF) as recommended by the ICRP. It also considers the issues which might influence a reassessment of both the value of the DDREF as well as its application in radiological protection. In this article, the problem is approached from a different perspective and starts by commenting on the limited scientific data used by Rühm et al 2016 (Ann. ICRP 45 262-79) to develop their analysis which ultimately leads them to use a linear-quadratic dose effect relationship to fit solid cancer mortality data from the Japanese life span study of atomic bomb survivors. The approach taken here includes more data on the induction of DNA double strand breaks and, using experimental data taken from the literature, directly relates the breaks to cell killing, chromosomal aberrations and somatic mutations. The relationships are expanded to describe the induction of cancer as arising from radiation induced cytological damage coupled to cell killing since the cancer mutated cell has to survive to express its malignant nature. Equations are derived for the induction of cancer after both acute and chronic exposure to sparsely ionising radiation. The equations are fitted to the induction of cancer in mice to illustrate a dose effect relationship over the total dose range. The 'DDREF' derived from the two equations varies with dose and the DDREF concept is called into question. Although the equation for

Radon level and radon effective dose rate determination in Moroccan dwellings using SSNTDs

International Nuclear Information System (INIS)

Oufni, L.; Misdaq, M.A.; Amrane, M.

2005-01-01

Inhalation of radon ( 222 Rn) and its daughter product are a major source of natural radiation exposure. The measurement of radon activity in dwelling is assuming ever increasing importance. It is known from recent surveys in many countries that radon and its progeny contribute significantly to total inhalation dose and it is fairly established that radon when inhaled in large quantity causes lung disorder. Keeping this in view, the indoor radon activity level and radon effective dose rate were carried out in the dwellings of Beni-Mellal, Khouribgra and Ben Guerir cities, Morocco, using the solid state nuclear track detectors (SSNTD) technique. Assuming an indoor occupancy factor of 0.8 and 0.4 for the equilibrium factor of radon indoors, we found that the 222 Rn effective dose rate in the studied dwellings ranges from 1.01 to 7.90mSvy -1 . The radon activity in the corresponding dwellings was found to vary from 40 to 532Bqm -3 . The radon activity has not only been found to vary with seasonal changes, but also with the age, the construction mode of houses, the ventilation conditions and with specific sites and geological materials

Dose Recalculation and the Dose-Guided Radiation Therapy (DGRT) Process Using Megavoltage Cone-Beam CT

International Nuclear Information System (INIS)

Cheung, Joey; Aubry, Jean-Francois; Yom, Sue S.; Gottschalk, Alexander R.; Celi, Juan Carlos; Pouliot, Jean

2009-01-01

Purpose: At University of California San Francisco, daily or weekly three-dimensional images of patients in treatment position are acquired for image-guided radiation therapy. These images can be used for calculating the actual dose delivered to the patient during treatment. In this article, we present the process of performing dose recalculation on megavoltage cone-beam computed tomography images and discuss possible strategies for dose-guided radiation therapy (DGRT). Materials and Methods: A dedicated workstation has been developed to incorporate the necessary elements of DGRT. Patient image correction (cupping, missing data artifacts), calibration, completion, recontouring, and dose recalculation are all implemented in the workstation. Tools for dose comparison are also included. Examples of image correction and dose analysis using 6 head-and-neck and 2 prostate patient datasets are presented to show possible tracking of interfraction dosimetric endpoint variation over the course of treatment. Results: Analysis of the head-and-neck datasets shows that interfraction treatment doses vary compared with the planning dose for the organs at risk, with the mean parotid dose and spinal cord D 1 increasing by as much as 52% and 10%, respectively. Variation of the coverage to the target volumes was small, with an average D 5 dose difference of 1%. The prostate patient datasets revealed accurate dose coverage to the targeted prostate and varying interfraction dose distributions to the organs at risk. Conclusions: An effective workflow for the clinical implementation of DGRT has been established. With these techniques in place, future clinical developments in adaptive radiation therapy through daily or weekly dosimetric measurements of treatment day images are possible.

SU-F-T-327: Total Body Irradiation In-Vivo Dose Measurements Using Optically Stimulated Luminescence (OSL) NanoDots and Farmer Type Ion Chamber

Energy Technology Data Exchange (ETDEWEB)

Kaur, H; Kumar, S; Sarkar, B; Ganesh, T; Giri, U; Jassal, K; Rathinamuthu, S; Gulia, G; Gopal, V; Mohanti, B; Munshi, A [Fortis Memorial Research Institute, Gurgaon, Haryana (India)

2016-06-15

Purpose: This study was performed to analyze the agreement between optically stimulated luminescence (OSL) nanoDots measured doses and 0.6 cc Farmer type ionization chamber measured doses during total body irradiation (TBI). Methods: In-vivo dose measurements using OSL nanoDots and Farmer chamber were done in a total of twelve patients who received TBI at our center by bilateral parallel-opposed beams technique. In this technique, the patient is kept inside the TBI box which is filled with rice bags and irradiated using two bilateral parallel opposed beams of 40×40 cm{sup 2} size with 45° collimator rotation at an SSD of 333.5 cm in an Elekta Synergy linear accelerator. All patients received a dose of 2 Gy in single fraction as conditioning regimen. The beams were equally weighted at the midplane of the box. The nanoDots were placed over forehead, right and left neck, right and left lung, umbilicus, right and left abdomen, medial part of thigh, knee and toe. A 0.6 cc Farmer chamber was placed in between the thighs of the patient. Measured doses are reported along with the statistical comparisons using paired sample t-test. Results: For the above sites the mean doses were 212.2±21.1, 218.2±7.6, 218.7±9.3, 215.6±9.5, 217.5±11.5, 214.5±7.7, 218.3±6.8, 221.5±15, 229.1±11.0, 220.5±7.7 and 223.3±5.1 cGy respectively. For all OSL measurements the mean dose was 218.6±11.8 cGy. Farmer chamber measurements yielded a mean dose of 208.8±15.6 cGy. Statistical analysis revealed that there was no significant difference between OSL measured doses in forehead, right and left neck, right and left lung, umbilicus, right and left abdomen and toe and Farmer chamber measured doses (0.72≤p≤0.06). However the mean OSL doses at thigh and knee were statistically different (p<0.05) from the Farmer chamber measurements. Conclusion: OSL measurements were found to be in agreement with Farmer type ionization chamber measurements in in-vivo dosimetry of TBI.

Noise reduction technology reduces radiation dose in chronic total occlusions percutaneous coronary intervention: a propensity score-matched analysis.

Science.gov (United States)

Maccagni, Davide; Benincasa, Susanna; Bellini, Barbara; Candilio, Luciano; Poletti, Enrico; Carlino, Mauro; Colombo, Antonio; Azzalini, Lorenzo

2018-03-23

Chronic total occlusions (CTO) percutaneous coronary intervention (PCI) is associated with high radiation dose. Our study aim was to evaluate the impact of the implementation of a noise reduction technology (NRT) on patient radiation dose during CTO PCI. A total of 187 CTO PCIs performed between February 2016 and May 2017 were analyzed according to the angiographic systems utilized: Standard (n = 60) versus NRT (n = 127). Propensity score matching (PSM) was performed to control for differences in baseline characteristics. Primary endpoints were Cumulative Air Kerma at Interventional Reference Point (AK at IRP), which correlates with patient's tissue reactions; and Kerma Area Product (KAP), a surrogate measure of patient's risk of stochastic radiation effects. An Efficiency Index (defined as fluoroscopy time/AK at IRP) was calculated for each procedure. Image quality was evaluated using a 5-grade Likert-like scale. After PSM, n = 55 pairs were identified. Baseline and angiographic characteristics were well matched between groups. Compared to the Standard system, NRT was associated with lower AK at IRP [2.38 (1.80-3.66) vs. 3.24 (2.04-5.09) Gy, p = 0.035], a trend towards reduction for KAP [161 (93-244) vs. 203 (136-363) Gycm 2 , p = 0.069], and a better Efficiency Index [16.75 (12.73-26.27) vs. 13.58 (9.92-17.63) min/Gy, p = 0.003]. Image quality was similar between the two groups (4.39 ± 0.53 Standard vs. 4.34 ± 0.47 NRT, p = 0.571). In conclusion, compared with a Standard system, the use of NRT in CTO PCI is associated with lower patient radiation dose and similar image quality.

Dose per unit area - a study of elicitation of nickel allergy

DEFF Research Database (Denmark)

Fischer, Louise Arup; Menné, Torkil; Johansen, Jeanne Duus

2007-01-01

BACKGROUND: Experimental sensitization depends upon the amount of allergen per unit skin area and is largely independent of the area size. OBJECTIVES: This study aimed at testing if this also applies for elicitation of nickel allergy. PATIENTS/METHODS: 20 nickel allergic individuals were tested...... with a patch test and a repeated open application test (ROAT). Nickel was applied on small and large areas. The varying parameters were area, total dose and dose per unit area. RESULTS: In the patch test, at a low concentration [15 microg nickel (microg Ni)/cm(2)], there were significantly higher scores...... on the large area with the same dose per area as the small area. At higher concentrations of nickel, no significant differences were found. In the ROAT at low concentration (6.64 microg Ni/cm(2)), it was found that the latency period until a reaction appeared was significantly shorter on the large area...

Polonium-210 in the total environment of Goa

International Nuclear Information System (INIS)

Avadhani, D.N.; Mahesh, H.M.; Siddappa, K.

2007-01-01

The paper deals with the distribution of 210 Po in total environment of Goa. The activity concentration of 210 Po in food, diet, water and air samples of the region were measured and the annual effective dose due to ingestion of this radionuclide was estimated. The activity of 210 Po in soil and sand samples vary from 3.2 Bq kg -1 to 186.2 Bq kg -1 with a mean value of 57.4Bq kg -1 and from 0.94 Bq kg -1 to 3.7 Bq kg -1 with the mean value of 1.8 Bq kg -1 respectively. Among food samples fish and prawn shows higher concentration of 210 Po. The Committed Effective Dose Equivalent due to ingestion of non veg meal, veg meal, breakfast and potable water were found to be 94.6 μSv y -1 , 49.1 μSv y -1 , 10.5 μSv y -1 and 4.2 μSv y -1 respectively. All the results are compared with the reported literature values and discussed in detail in this paper. (author)

SU-E-T-92: Achieving Desirable Lung Doses in Total Body Irradiation Based On in Vivo Dosimetry and Custom Tissue Compensation

International Nuclear Information System (INIS)

Cui, G; Shiu, A; Zhou, S; Cui, J; Ballas, L

2015-01-01

Purpose: To achieve desirable lung doses in total body irradiation (TBI) based on in vivo dosimetry and custom tissue compensation. Methods: The 15 MV photon beam of a Varian TrueBeam STx linac was used for TBI. Patients were positioned in the lateral decubitus position for AP/PA treatment delivery. Dose was calculated using the midpoint of the separation distance across the patient’s umbilicus. Patients received 200 cGy twice daily for 3 days. The dose rate at the patient’s midplane was approximately 10 cGy/min. Cerrobend blocks with a 5-HVL thickness were used for the primary lung shielding. A custom styrofoam holder for rice-flour filled bags was created based on the lung block cutouts. This was used to provide further lung shielding based on in vivo dose measurements. Lucite plates and rice-flour bags were placed in the head, neck, chest, and lower extremity regions during the treatment to compensate for the beam off-axis output variations. Two patients were included in the study. Patients 1 and 2 received a craniospinal treatment (1080 cGy) and a mediastinum treatment (2520 cGy), respectively, before the TBI. During the TBI nanoDot dosimeters were placed on the patient skin in the forehead, neck, umbilicus, and lung regions for dose monitoring. The doses were readout immediately after the treatment. Based on the readings, fine tuning of the thickness of the rice-flour filled bags was exploited to achieve the desirable lung doses. Results: For both patients the mean lung doses, which took into consideration all treatments, were controlled within 900 +/−10% cGy, as desired. Doses to the forehead, neck, and umbilicus were achieved within +/−10% of the prescribed dose (1200 cGy). Conclusion: A reliable and robust method was developed to achieve desirable lung doses and uniform body dose in TBI based on in vivo dosimetry and custom tissue compensator

SU-E-T-92: Achieving Desirable Lung Doses in Total Body Irradiation Based On in Vivo Dosimetry and Custom Tissue Compensation

Energy Technology Data Exchange (ETDEWEB)

Cui, G; Shiu, A; Zhou, S; Cui, J; Ballas, L [Univ Southern California, Los Angeles, CA (United States)

2015-06-15

Purpose: To achieve desirable lung doses in total body irradiation (TBI) based on in vivo dosimetry and custom tissue compensation. Methods: The 15 MV photon beam of a Varian TrueBeam STx linac was used for TBI. Patients were positioned in the lateral decubitus position for AP/PA treatment delivery. Dose was calculated using the midpoint of the separation distance across the patient’s umbilicus. Patients received 200 cGy twice daily for 3 days. The dose rate at the patient’s midplane was approximately 10 cGy/min. Cerrobend blocks with a 5-HVL thickness were used for the primary lung shielding. A custom styrofoam holder for rice-flour filled bags was created based on the lung block cutouts. This was used to provide further lung shielding based on in vivo dose measurements. Lucite plates and rice-flour bags were placed in the head, neck, chest, and lower extremity regions during the treatment to compensate for the beam off-axis output variations. Two patients were included in the study. Patients 1 and 2 received a craniospinal treatment (1080 cGy) and a mediastinum treatment (2520 cGy), respectively, before the TBI. During the TBI nanoDot dosimeters were placed on the patient skin in the forehead, neck, umbilicus, and lung regions for dose monitoring. The doses were readout immediately after the treatment. Based on the readings, fine tuning of the thickness of the rice-flour filled bags was exploited to achieve the desirable lung doses. Results: For both patients the mean lung doses, which took into consideration all treatments, were controlled within 900 +/−10% cGy, as desired. Doses to the forehead, neck, and umbilicus were achieved within +/−10% of the prescribed dose (1200 cGy). Conclusion: A reliable and robust method was developed to achieve desirable lung doses and uniform body dose in TBI based on in vivo dosimetry and custom tissue compensator.

Should we ignore U-235 series contribution to dose?

International Nuclear Information System (INIS)

Beaugelin-Seiller, Karine; Goulet, Richard; Mihok, Steve; Beresford, Nicholas A.

2016-01-01

Environmental Risk Assessment (ERA) methodology for radioactive substances is an important regulatory tool for assessing the safety of licensed nuclear facilities for wildlife, and the environment as a whole. ERAs are therefore expected to be both fit for purpose and conservative. When uranium isotopes are assessed, there are many radioactive decay products which could be considered. However, risk assessors usually assume 235 U and its daughters contribute negligibly to radiological dose. The validity of this assumption has not been tested: what might the 235 U family contribution be and how does the estimate depend on the assumptions applied? In this paper we address this question by considering aquatic wildlife in Canadian lakes exposed to historic uranium mining practices. A full theoretical approach was used, in parallel to a more realistic assessment based on measurements of several elements of the U decay chains. The 235 U family contribution varied between about 4% and 75% of the total dose rate depending on the assumptions of the equilibrium state of the decay chains. Hence, ignoring the 235 U series will not result in conservative dose assessments for wildlife. These arguments provide a strong case for more in situ measurements of the important members of the 235 U chain and for its consideration in dose assessments. - Highlights: • Realistic ecological risk assessment infers a complete inventory of radionuclides. • U-235 family may not be minor when assessing total dose rates experienced by biota. • There is a need to investigate the real state of equilibrium decay of U chains. • There is a need to improve the capacity to measure all elements of the U decay chains.

Reduced fungicide doses in cereals: Which parameters to consider?

DEFF Research Database (Denmark)

Jørgensen, Lise Nistrup

2015-01-01

dose. In spring barley the economically optimum input can vary from 0-2 treatments with a total fungicide use equivalent to 0.25 to 0.5 times the recommended dose. Applying reducing rates should never result in significant inferior control and economical yield losses. A recent review concluded......, the pathogen, disease pressure and timing of treatments. Certain diseases are known to require higher input (40- 75% rates) for achieving satisfactory control – this is the case for Septoria leaf blight, Rhynchosporium net blotch and Fusarium head blight, whereas most rust diseases generally have been found...... on well-established disease attack. Rates also have to be adjusted according to canopy structures. Early timing on a small canopy requires less fungicide than a full canopy around heading. The knowledge gathered concerning fungicide rates has led to great focus on the importance of optimizing timing...

Total curvature and total torsion of knotted random polygons in confinement

Science.gov (United States)

Diao, Yuanan; Ernst, Claus; Rawdon, Eric J.; Ziegler, Uta

2018-04-01

Knots in nature are typically confined spatially. The confinement affects the possible configurations, which in turn affects the spectrum of possible knot types as well as the geometry of the configurations within each knot type. The goal of this paper is to determine how confinement, length, and knotting affect the total curvature and total torsion of random polygons. Previously published papers have investigated these effects in the unconstrained case. In particular, we analyze how the total curvature and total torsion are affected by (1) varying the length of polygons within a fixed confinement radius and (2) varying the confinement radius of polygons with a fixed length. We also compare the total curvature and total torsion of groups of knots with similar complexity (measured as crossing number). While some of our results fall in line with what has been observed in the studies of the unconfined random polygons, a few surprising results emerge from our study, showing some properties that are unique due to the effect of knotting in confinement.

Intraoperative Low-Dose Ketamine Infusion Reduces Acute Postoperative Pain Following Total Knee Replacement Surgery: A Prospective, Randomized Double-Blind Placebo-Controlled Trial

International Nuclear Information System (INIS)

Pelin Cengiz, P.; Gokcinar, D.; Karabeyoglu, I.; Topcu, H.; Cicek, G. S.; Gogus, N.

2014-01-01

Objective: To evaluate the effect of intraoperative low-dose ketamine with general anesthesia on postoperative pain after total knee replacement surgery. Study Design: A randomized, double-blind comparative study. Place and Duration of Study: Ankara Numune Training and Research Hospital, Turkey, from January and June 2011. Methodology: Sixty adults undergoing total knee arthroplasty were enrolled in this study. The patients were randomly allocated into two groups of equal size to receive either racemic ketamine infusion (6.25 g/kg/minute) or the same volume of saline. A visual analogue scale (VAS) was used to measure each patient's level of pain at 1, 3, 6, 12, and 24 hours after surgery. Time to first analgesic request, postoperative morphine consumption and the incidence of side effects were also recorded. Results: Low-dose ketamine infusion prolonged the time to first analgesic request. It also reduced postoperative cumulative morphine consumption at 1, 3, 6, 12, and 24 hours postsurgery (p < 0.001). Postoperative VAS scores were also significantly lower in the ketamine group than placebo, at all observation times. Incidences of side effects were similar in both study groups. Conclusion: Intraoperative continuous low-dose ketamine infusion reduced pain and postoperative analgesic consumption without affecting the incidence of side effects. (author)

Low-dose (10-Gy) total skin electron beam therapy for cutaneous T-cell lymphoma: an open clinical study and pooled data analysis.

Science.gov (United States)

Kamstrup, Maria R; Gniadecki, Robert; Iversen, Lars; Skov, Lone; Petersen, Peter Meidahl; Loft, Annika; Specht, Lena

2015-05-01

Cutaneous T-cell lymphomas (CTCLs) are dominated by mycosis fungoides (MF) and Sézary syndrome (SS), and durable disease control is a therapeutic challenge. Standard total skin electron beam therapy (TSEBT) is an effective skin-directed therapy, but the possibility of retreatments is limited to 2 to 3 courses in a lifetime due to skin toxicity. This study aimed to determine the clinical effect of low-dose TSEBT in patients with MF and SS. In an open clinical study, 21 patients with MF/SS stages IB to IV were treated with low-dose TSEBT over dose of 10 Gy in 10 fractions. Data from 10 of these patients were published previously but were included in the current pooled data analysis. Outcome measures were response rate, duration of response, and toxicity. The overall response rate was 95% with a complete cutaneous response or a very good partial response rate (dose (10-Gy) TSEBT offers a high overall response rate and is relatively safe. With this approach, reirradiation at times of relapse or progression is likely to be less toxic than standard dose TSEBT. It remains to be established whether adjuvant and combination treatments can prolong the beneficial effects of low-dose TSEBT. Copyright © 2015 Elsevier Inc. All rights reserved.

Spot Urine Protein-to-Creatinine Ratio to Predict the Magnitude of 24-Hour Total Proteinuria in Preeclampsia of Varying Severity.

Science.gov (United States)

Kucukgoz Gulec, Umran; Sucu, Mete; Ozgunen, Fatma Tuncay; Buyukkurt, Selim; Guzel, Ahmet Baris; Paydas, Saime

2017-10-01

The predictive value of spot urine protein-to-creatinine ratio (PCR) for estimating total 24-hour proteinuria in severe preeclampsia is unclear. This study aimed to assess the diagnostic accuracy of spot urine PCR for ascertaining the magnitude of proteinuria in women with preeclampsia of varying severity. A total of 205 patients with prediagnosed preeclampsia were included in this prospective cohort study. Patients were allocated into one of the three groups categorized by severity of disease, as follows: gestational hypertension, group 1 (n = 41); preeclampsia, group 2 (n = 88); and severe preeclampsia, group 3 (n = 76). We assessed the spot urine PCRs to determine significant proteinuria and the magnitude of proteinuria in these groups. The spot urine PCR was 0.53, with 81% sensitivity and 93% specificity to detect significant proteinuria. A significant correlation was found between PCR and 24-hour total proteinuria in group 1 (r = 0.473, P = 0.002). There were also significant correlations in group 2 (r = 0.814, P spot urine PCR to estimate 24-hour total proteinuria in severe preeclampsia was Y = 832.02X + 378.74 mg (r 2  = 0.8304). Although 24-hour urine collection remains a merely reliable test to determine the degree of total proteinuria, our findings suggest that it is likely to assess the magnitude of proteinuria by the spot urine PCR, especially in severe preeclampsia. www.clinicaltrials.govNCT01623791. Copyright © 2017 The Society of Obstetricians and Gynaecologists of Canada/La Société des obstétriciens et gynécologues du Canada. Published by Elsevier Inc. All rights reserved.

Urinary excretion of total isothiocyanates from cruciferous vegetables shows high dose-response relationship and may be a useful biomarker for isothiocyanate exposure

DEFF Research Database (Denmark)

Kristensen, Mette; Krogholm, Kirstine Suszkiewicz; Frederiksen, Hanne

2007-01-01

in urine was quanti- fied as the cyclocondensation product of 1,2-bezenedithiol by high performance liquid chromatography. Results The total urinary excretion of ITCs correlated significantly with the two doses of ITC from diets with high or low cruciferous content (r(s) = 0.90, P

Dose characteristics and LET spectra on and inside the spherical phantom onboard of ISS

International Nuclear Information System (INIS)

Jadrnickova, I.; Brabcova, K.; Mrazova, Z.; Spurny, F.; Shurshakov, V.A.; Kartsev, I.S.; Tolochek, R.V.

2010-01-01

To estimate the radiation risk of spacecraft crew during the mission, it is necessary to measure dose distribution at various compartments, on and inside the human body that can be simulated using various phantoms. Due to some convenient characteristics (especially small weight and dimensions), passive detectors are used to measure dosimetric quantities onboard spacecraft. This contribution deals with the measurement of dosimetric characteristics and spectra of linear energy transfer (LET) onboard the International Space Station (ISS) during two experiments with tissue-equivalent spherical Russian phantom MATROSHKA-R realized in years 2006 and 2008. To obtain LET spectra, total absorbed doses, and dose equivalents, we used combination of plastic nuclear track detectors and thermoluminescence detectors. The detectors were placed at various locations on the surface of the MATROSHKA-R phantom; some detectors were also inserted inside this phantom. The variation of dosimetric quantities obtained during both missions is discussed. The dose characteristics vary with the position of the detectors on or inside the phantom; the absorbed dose and dose equivalent can differ almost twice.

The Impact of Combining a Low-Tube Voltage Acquisition with Iterative Reconstruction on Total Iodine Dose in Coronary CT Angiography

Directory of Open Access Journals (Sweden)

Toon Van Cauteren

2017-01-01

Full Text Available Objectives. To assess the impact of combining low-tube voltage acquisition with iterative reconstruction (IR techniques on the iodine dose in coronary CTA. Methods. Three minipigs underwent CCTA to compare a standard of care protocol with two alternative study protocols combining low-tube voltage and low iodine dose with IR. Image quality was evaluated objectively by the CT value, signal-to-noise ratio (SNR, and contrast-to-noise ratio (CNR in the main coronary arteries and aorta and subjectively by expert reading. Statistics were performed by Mann–Whitney U test and Chi-square analysis. Results. Despite reduced iodine dose, both study protocols maintained CT values, SNR, and CNR compared to the standard of care protocol. Expert readings confirmed these findings; all scans were perceived to be of at least diagnostically acceptable quality on all evaluated parameters allowing image interpretation. No statistical differences were observed (all p values > 0.11, except for streak artifacts (p=0.02 which were considered to be more severe, although acceptable, with the 80 kVp protocol. Conclusions. Reduced tube voltage in combination with IR allows a total iodine dose reduction between 37 and 50%, by using contrast media with low iodine concentrations of 200 and 160 mg I/mL, while maintaining image quality.

Influence of dose, dose rate, and radiation quality on radiation carcinogenesis and life shortening in RFM and BALB/C mice

International Nuclear Information System (INIS)

Ullrich, R.L.; Storer, J.B.

1978-01-01

The effects produced by 137 Cs gamma rays delivered at a high (45 rads/min) or intermediate (8.2 rads/day) dose rate and the effect of fission neutrons at a high (25 rads/min) and low (1 rad/day) rate in a population of nearly 30,000 RFM and 11,000 BALB/c mice have been studied. Gamma ray doses ranged from 10 to 400 rads with the RFM's and from 50-400 rads with the BALB/c's, while neutron doses ranged from 5 to 200 rads with both strains. The present paper will present an overview of these data and the general findings while subsequent publications will present detailed analyses of each aspect. A variety of neoplasms were sensitive to induction after radiation exposure, including tumors of both reticular tissue origin (leukemia, lymphoma, etc.) and solid tumors. For the RFM, thymic lymphomas were the dominant reticular tissue neoplasm while the majority of solid tumors were either lung adenomas or fit into the broad category of endocrine related tumors, including ovarian, pituitary, harderian, and uterine tumors. The BALB/c was much less sensitive to induction of reticular tissue neoplasms. The tumors that were most sensitive to induction included malignant lung carcinomas, mammary adenocarcinomas and ovarian tumors. In general for both life shortening and tumor induction after gamma ray exposures, when the low to intermediate dose range was sufficiently defined, linearity could be rejected and a dose squared or linear-dose squared relationship adequately fit the data. For neutron exposures, on the other hand, linear relationships were the general finding. The RBE for neutrons varied with tumor type and total dose level. For gamma ray irradiation, the intermediate dose rate resulted in a decreased effectiveness in all cases, while for neutron exposures the dose rate relationships were more complex

Effects of varied doses of psilocybin on time interval reproduction in human subjects.

Science.gov (United States)

Wackermann, Jirí; Wittmann, Marc; Hasler, Felix; Vollenweider, Franz X

2008-04-11

Action of a hallucinogenic substance, psilocybin, on internal time representation was investigated in two double-blind, placebo-controlled studies: Experiment 1 with 12 subjects and graded doses, and Experiment 2 with 9 subjects and a very low dose. The task consisted in repeated reproductions of time intervals in the range from 1.5 to 5s. The effects were assessed by parameter kappa of the 'dual klepsydra' model of internal time representation, fitted to individual response data and intra-individually normalized with respect to initial values. The estimates kappa were in the same order of magnitude as in earlier studies. In both experiments, kappa was significantly increased by psilocybin at 90 min from the drug intake, indicating a higher loss rate of the internal duration representation. These findings are tentatively linked to qualitative alterations of subjective time in altered states of consciousness.

Organ or tissue doses, effective dose and collective effective dose from X-ray diagnosis, in Japan

International Nuclear Information System (INIS)

Murayama, Takashi; Nishizawa, Kanae; Noda, Yutaka; Kumamoto, Yoshikazu; Iwai, Kazuo.

1996-01-01

Effective doses and collective effective doses from X-ray diagnostic examinations were calculated on the basis of the frequency of examinations estimated by a nationwide survey and the organ or tissue doses experimentally determined. The average organ or tissue doses were determined with thermoluminescence dosimeters put at various sites of organs or tissues in an adult and a child phantom. Effective doses (effective dose equivalents) were calculated as the sum of the weighted equivalent doses in all the organs or tissues of the body. As the examples of results, the effective doses per radiographic examination were approximately 7 mGy for male, and 9 mGy for female angiocardiography, and about 3 mGy for barium meal. Annual collective effective dose from X-ray diagnostic examinations in 1986 were about 104 x 10 3 person Sv from radiography and 118 x 10 3 person Sv from fluoroscopy, with the total of 222 x 10 3 person Sv. (author)

Summary of the U.S. specimen matrix for the HFIR 13J varying temperature irradiation capsule

International Nuclear Information System (INIS)

Zinkle, S.J.

1998-01-01

The US specimen matrix for the collaborative DOE/Monbusho HFIR 13J varying temperature irradiation capsule contains two ceramics and 29 different metals, including vanadium alloys, ferritic/martensitic steels, pure iron, austenitic stainless steels, nickel alloys, and copper alloys. This experiment is designed to provide fundamental information on the effects of brief low-temperature excursions on the tensile properties and microstructural evolution of a wide range of materials irradiated at nominal temperatures of 350 and 500 C to a dose of ∼5 dpa. A total of 340 miniature sheet tensile specimens and 274 TEM disks are included in the US-supplied matrix for the irradiation capsule

Radiation dose from cigarette tobacco

International Nuclear Information System (INIS)

Papastefanou, Constantin

2008-01-01

The radioactivity in tobacco leaves collected from 15 different regions of Greece before cigarette production was studied in order to estimate the effective dose from cigarette tobacco due to the naturally occurring primordial radionuclides, such as 226 Ra and 210 Pb of the uranium series and 228 Ra of the thorium series and or man-made produced radionuclides, such as 137 Cs of Chernobyl origin. Gamma-ray spectrometry was applied using Ge planar and coaxial type detectors of high resolution and high efficiency. It was concluded that the annual effective dose due to inhalation for adults (smokers) for 226 Ra varied from 42.5 to 178.6 μSv y -1 (average 79.7 μSv y -1 ), while for 228 Ra from 19.3 to 116.0 μSv y -1 (average 67.1 μSv y -1 ) and for 210 Pb from 47.0 to 134.9 μSv y -1 (average 104.7 μSv y -1 ), that is the same order of magnitude for each radionuclide. The sum of the effective dose of the three natural radionuclides varied from 151.9 to 401.3 μSv y -1 (average 251.5 μSv y -1 ). The annual effective dose from 137 Cs of Chernobyl origin was three orders of magnitude lower as it varied from 70.4 to 410.4 μSv y -1 (average 199.3 μSv y -1 ). (author)

Compendium of Current Total Ionizing Dose and Displacement Damage Results from NASA Goddard Space Flight Center and Selected NASA Electronic Parts and Packaging Program

Science.gov (United States)

Topper, Alyson D.; Campola, Michael J.; Chen, Dakai; Casey, Megan C.; Yau, Ka-Yen; Cochran, Donna J.; LaBel, Kenneth A.; Ladbury, Raymond L.; Lauenstein, Jean-Marie; Mondy, Timothy K.;

A dosing algorithm for metformin based on the relationships between exposure and renal clearance of metformin in patients with varying degrees of kidney function.

Science.gov (United States)

Duong, Janna K; Kroonen, M Y A M; Kumar, S S; Heerspink, H L; Kirkpatrick, C M; Graham, G G; Williams, K M; Day, R O

2017-08-01

The aims of this study were to investigate the relationship between metformin exposure, renal clearance (CL R ), and apparent non-renal clearance of metformin (CL NR /F) in patients with varying degrees of kidney function and to develop dosing recommendations. Plasma and urine samples were collected from three studies consisting of patients with varying degrees of kidney function (creatinine clearance, CL CR ; range, 14-112 mL/min). A population pharmacokinetic model was built (NONMEM) in which the oral availability (F) was fixed to 0.55 with an estimated inter-individual variability (IIV). Simulations were performed to estimate AUC 0-τ , CL R , and CL NR /F. The data (66 patients, 327 observations) were best described by a two-compartment model, and CL CR was a covariate for CL R . Mean CL R was 17 L/h (CV 22%) and mean CL NR /F was 1.6 L/h (69%).The median recovery of metformin in urine was 49% (range 19-75%) over a dosage interval. When CL R increased due to improved renal function, AUC 0-τ decreased proportionally, while CL NR /F did not change with kidney function. Target doses (mg/day) of metformin can be reached using CL CR /3 × 100 to obtain median AUC 0-12 of 18-26 mg/L/h for metformin IR and AUC 0-24 of 38-51 mg/L/h for metformin XR, with C max  kidney function to maintain consistent drug exposure. However, there is still marked IIV and therapeutic drug monitoring of metformin plasma concentrations is recommended.

Long-term brain structural magnetic resonance imaging and cognitive functioning in children treated for acute lymphoblastic leukemia with high-dose methotrexate chemotherapy alone or combined with CNS radiotherapy at reduced total dose to 12 Gy

Energy Technology Data Exchange (ETDEWEB)

Zajac-Spychala, Olga; Pilarczyk, Jakub; Derwich, Katarzyna; Wachowiak, Jacek [Poznan University of Medical Sciences, Department of Pediatric Oncology, Hematology and Transplantology, Poznan (Poland); Pawlak, Mikolaj A. [Poznan University of Medical Sciences, Department of Neurology and Cerebrovascular Disorders, Poznan (Poland); Karmelita-Katulska, Katarzyna [Poznan University of Medical Sciences, Department of Neuroradiology, Poznan (Poland)

2017-02-15

The aim of this study was to assess the long-term side effects of central nervous system prophylaxis (high-dose chemotherapy alone vs chemotherapy and CNS radiotherapy) according to the ALL IC-BFM 2002. Thirty-tree children aged 6.7-19.9 years have been studied. The control group consisted of 12 children newly diagnosed with acute lymphoblastic leukemia. We assessed subcortical gray matter volume using automatic MRI segmentation and cognitive performance to identify differences between two therapeutic schemes and patients prior to treatment. Patients treated with chemotherapy and CNS radiotherapy had smaller hippocampi than two other subgroups and lower IQ score than patients treated with chemotherapy alone. Both treated groups, whether with chemotherapy only or in combination with CNS radiotherapy, had significantly lower volumes of caudate nucleus and performed significantly worse on measures of verbal fluency in comparison with patients prior to treatment. There were no differences in the mean volumes of total white matter, total gray matter, thalamus, putamen, and amygdala between the studied groups. In all children treated according to the ALL IC-BFM 2002 with high-dose chemotherapy, both decreased volume of selected subcortical structures and cognitive impairment was observed, especially in children who received chemotherapy in combination with reduced dose CNS radiotherapy. In all children treated according to the ALL IC-BFM 2002 with high-dose chemotherapy, both decreased volume of selected subcortical structures and cognitive impairment were observed, especially in children who received chemotherapy in combination with CNS radiotherapy. (orig.)

Long-term brain structural magnetic resonance imaging and cognitive functioning in children treated for acute lymphoblastic leukemia with high-dose methotrexate chemotherapy alone or combined with CNS radiotherapy at reduced total dose to 12 Gy

International Nuclear Information System (INIS)

Zajac-Spychala, Olga; Pilarczyk, Jakub; Derwich, Katarzyna; Wachowiak, Jacek; Pawlak, Mikolaj A.; Karmelita-Katulska, Katarzyna

2017-01-01

The aim of this study was to assess the long-term side effects of central nervous system prophylaxis (high-dose chemotherapy alone vs chemotherapy and CNS radiotherapy) according to the ALL IC-BFM 2002. Thirty-tree children aged 6.7-19.9 years have been studied. The control group consisted of 12 children newly diagnosed with acute lymphoblastic leukemia. We assessed subcortical gray matter volume using automatic MRI segmentation and cognitive performance to identify differences between two therapeutic schemes and patients prior to treatment. Patients treated with chemotherapy and CNS radiotherapy had smaller hippocampi than two other subgroups and lower IQ score than patients treated with chemotherapy alone. Both treated groups, whether with chemotherapy only or in combination with CNS radiotherapy, had significantly lower volumes of caudate nucleus and performed significantly worse on measures of verbal fluency in comparison with patients prior to treatment. There were no differences in the mean volumes of total white matter, total gray matter, thalamus, putamen, and amygdala between the studied groups. In all children treated according to the ALL IC-BFM 2002 with high-dose chemotherapy, both decreased volume of selected subcortical structures and cognitive impairment was observed, especially in children who received chemotherapy in combination with reduced dose CNS radiotherapy. In all children treated according to the ALL IC-BFM 2002 with high-dose chemotherapy, both decreased volume of selected subcortical structures and cognitive impairment were observed, especially in children who received chemotherapy in combination with CNS radiotherapy. (orig.)

Doses of external exposure in Jordan house due to gamma-emitting natural radionuclides in building materials.

Science.gov (United States)

Al-Jundi, J; Ulanovsky, A; Pröhl, G

2009-10-01

The use of building materials containing naturally occurring radionuclides as (40)K, (232)Th, and (238)U and their progeny results in external exposures of the residents of such buildings. In the present study, indoor dose rates for a typical Jordan concrete room are calculated using Monte Carlo method. Uniform chemical composition of the walls, floor and ceiling as well as uniform mass concentrations of the radionuclides in walls, floor and ceiling are assumed. Using activity concentrations of natural radionuclides typical for the Jordan houses and assuming them to be in secular equilibrium with their progeny, the maximum annual effective doses are estimated to be 0.16, 0.12 and 0.22 mSv a(-1) for (40)K, (232)Th- and (238)U-series, respectively. In a total, the maximum annual effective indoor dose due to external gamma-radiation is 0.50 mSv a(-1). Additionally, organ dose coefficients are calculated for all organs considered in ICRP Publication 74. Breast, skin and eye lenses have the maximum equivalent dose rate values due to indoor exposures caused by the natural radionuclides, while equivalent dose rates for uterus, colon (LLI) and small intestine are found to be the smallest. More specifically, organ dose rates (nSv a(-1)per Bq kg(-1)) vary from 0.044 to 0.060 for (40)K, from 0.44 to 0.60 for radionuclides from (238)U-series and from 0.60 to 0.81 for radionuclides from (232)Th-series. The obtained organ and effective dose conversion coefficients can be conveniently used in practical dose assessment tasks for the rooms of similar geometry and varying activity concentrations and local-specific occupancy factors.

Annual effective dose due to natural radioactivity in drinking water

International Nuclear Information System (INIS)

Padma Savithri, P.; Srivastava, S.K.; Balbudhe, A.Y.; Vishwa Prasad, K.; Ravi, P.M.; Tripathi, R.M.

2014-01-01

Natural radioactivity concentration in drinking water supply in and round Hyderabad, Secunderabad was determined. The observed gross alpha activity found in water samples vary from 0.027±0.014 Bq/L to 0.042±0.015 Bq/L with average 0.035 Bq/L while beta activity in all the samples are less than 0.076 Bq/l. Contributions of the drinking water samples to total annual effective dose equivalent from 238 U, 234 U, 230 Th, 26 Ra, 210 Po, 232 Th, 228 Th 210 Pb and 228 Ra are 1.14, 1.24, 5.30, 7.07, 30.3, 5.81, 1.82, 38.3 and 38.3 μSvy -1 for adults. The results indicate that the annual effective doses are below the WHO recommended reference level for α and β in food and drinking samples. (author)

Optimizing Radiation Doses for Computed Tomography Across Institutions: Dose Auditing and Best Practices.

Science.gov (United States)

Demb, Joshua; Chu, Philip; Nelson, Thomas; Hall, David; Seibert, Anthony; Lamba, Ramit; Boone, John; Krishnam, Mayil; Cagnon, Christopher; Bostani, Maryam; Gould, Robert; Miglioretti, Diana; Smith-Bindman, Rebecca

2017-06-01

Radiation doses for computed tomography (CT) vary substantially across institutions. To assess the impact of institutional-level audit and collaborative efforts to share best practices on CT radiation doses across 5 University of California (UC) medical centers. In this before/after interventional study, we prospectively collected radiation dose metrics on all diagnostic CT examinations performed between October 1, 2013, and December 31, 2014, at 5 medical centers. Using data from January to March (baseline), we created audit reports detailing the distribution of radiation dose metrics for chest, abdomen, and head CT scans. In April, we shared reports with the medical centers and invited radiology professionals from the centers to a 1.5-day in-person meeting to review reports and share best practices. We calculated changes in mean effective dose 12 weeks before and after the audits and meeting, excluding a 12-week implementation period when medical centers could make changes. We compared proportions of examinations exceeding previously published benchmarks at baseline and following the audit and meeting, and calculated changes in proportion of examinations exceeding benchmarks. Of 158 274 diagnostic CT scans performed in the study period, 29 594 CT scans were performed in the 3 months before and 32 839 CT scans were performed 12 to 24 weeks after the audit and meeting. Reductions in mean effective dose were considerable for chest and abdomen. Mean effective dose for chest CT decreased from 13.2 to 10.7 mSv (18.9% reduction; 95% CI, 18.0%-19.8%). Reductions at individual medical centers ranged from 3.8% to 23.5%. The mean effective dose for abdominal CT decreased from 20.0 to 15.0 mSv (25.0% reduction; 95% CI, 24.3%-25.8%). Reductions at individual medical centers ranged from 10.8% to 34.7%. The number of CT scans that had an effective dose measurement that exceeded benchmarks was reduced considerably by 48% and 54% for chest and abdomen, respectively. After

Radiation doses to the eye lenses in computed tomography of the orbit and the petrous bone

International Nuclear Information System (INIS)

Neufang, K.F.R.; Zanella, F.E.; Ewen, K.; Koeln Univ.

1987-01-01

Standard CT examinations of the orbit and the petrous bone were simulated with a tissue-equivalent human skull phantom on a Somatom DR 2 scanner. The orientation of the scan planes and the scan parameters including thickness, number of slices and mAs were varied according to the assumed diagnostic problems. The total radiation doses in the region of the eye lenses were measured with thermoluminescent dosimeters. If the globes are located within the X-ray field, the total radiation doses received by the lenses increased with the number and the thickness of the slices and the mAs. The highest radiation doses were found in contiguous thinsection scans of the orbit in axial (52 mGy) or direct coronal (47 mGy) orientation. In cases where the globes were located outside the X-ray field, the radiation doses received by the eye lenses could be reduced by a factor of 16, resulting in only 3.1-3.4 mGy for a complete axial study of the inner ear. Recommendations are given how to reduce the radiation exposure to the eye lenses without loss of diagnostical information. (orig.)

Variation in radiation doses in paediatric cardiac catheterisation procedures

International Nuclear Information System (INIS)

Al-Haj, A. N.; Lobriguito, A. M.; Rafeh, W.

2008-01-01

Paediatric cardiac catheterisation involves diagnostic and therapeutic procedures that range from simple to complex and can subject paediatric patients to varying radiation doses. The study aims to determine the variation in entrance doses in patients in terms of dose-area product (DAP) values and to investigate the methods for optimising radiation protection. A total of 190 paediatric patients belonging to age groups 0, 1, 5 and 10 y who underwent diagnostic and six selected therapeutic procedures at King Faisal Specialist Hospital and Research Centre, Riyadh (Saudi Arabia) were included in the study. Therapeutic procedures include coarctation (COA), patent ductus arteriosus (PDA), radiofrequency ablation, pulmonary, embolisation and septostomy. Fluoroscopy and cine radiography were used in all procedures. Patient demography (weight, age, gender and height), radiographic technique factors, fluoroscopy and cine time, frame rate, and DAP values were taken from patients records. Effective doses for each procedure were estimated from the DAP values. The mean DAP per procedure were analysed for correlation with patient equivalent cylindrical diameter, weight, fluoroscopy time and number of frames. Factors influencing the variation in doses were investigated. Initial results show that PDA occlusion has the highest mean DAP value of 23.21 Gy-cm 2 , while the diagnostic and septostomy procedures have the lowest value of 7.77 and 6.95 Gy-cm 2 , respectively. (authors)

TH-EF-BRB-09: Total Body Irradiation with Uniform MU and Modulated Arc Segments, UMMS-TBI

Energy Technology Data Exchange (ETDEWEB)

Yi, B; Chung, H; Mutaf, Y; Prado, K [University of Maryland School of Medicine, Baltimore, MD (United States)

2016-06-15

Purpose: To test a novel total body irradiation (TBI) system using conformal partial arc with patient lying on the stationary couch which is biologically equivalent to a moving couch TBI. This improves the scanning field TBI, which is previously presented. Methods: The Uniform MU Modulated arc Segments TBI or UMMS-TBI scans the treatment plane with a constant machine dose rate and a constant gantry rotation speed. A dynamic MLC pattern which moves while gantry rotates has been designed so that the treatment field moves same distance at the treatment plane per each gantry angle, while maintaining same treatment field size (34cm) at the plane. Dose across the plane varies due to the geometric differences including the distance from the source to a point of interest and the different attenuation from the slanted depth which changes the effective depth. Beam intensity is modulated to correct the dose variation across the plane by assigning the number of gantry angles inversely proportional to the uncorrected dose. Results: Measured dose and calculated dose matched within 1 % for central axis and 3% for off axis for various patient scenarios. Dose from different distance does not follow the inverse square relation as it is predicted from calculation. Dose uniformity better than 5% across 180 cm at 10cm depth is achieved by moving the gantry from −55 to +55 deg. Total treatment time for 2 Gy AP/PA fields is 40–50 minutes excluding patient set up time, at the machine dose rate of 200 MU/min. Conclusion: This novel technique, yet accurate but easy to implement enables TBI treatment in a small treatment room with less program development preparation than other techniques. The VMAT function of treatment delivery is not required to modulate beams. One delivery pattern can be used for different patients by changing the monitor units.

Natural radiation dose to Gammarus from Hudson river

International Nuclear Information System (INIS)

Paschoa, A.S.; Wrenn, M.E.; Eisenbud, M.

1979-01-01

The purpose of this investigation is to evaluate the natural radiation dose rate to whole body and components of the Gammarus species, a zooplankton which occurs in the Hudson River among other places, and to compare the results with the upper limits of dose rates from man-made sources. The alpha dose rates to the exoskeleton and soft tissues are about 10 times the average alpha dose rate to the whole body, assuming uniform distribution of 226 Ra. The natural alpha radiation dose rate to Gammarus represents only about 5% of the total natural dose to the organism, i.e., 492 mrad/yr. The external dose rate due to 40 K, 238 U plus daughters and 232 Th plus daughters accumulated in the sediments comprise 91% of that total natural dose rate, the remaining percentage being due to natural internal beta emitters and cosmic radiation. Man-made sources can cause an external dose rate up to 224 mrad/yr, which comprises roughly 1/3 of the total dose rate (up to 716 mrad/yr; natural plus man-made) to the Gammarus of Hudson River in front of Indian Point Nuclear Power Station. However, in terms of dose-equivalent the natural sources of radiation would contribute more than 75% of the total dose to Gammarus

Cancer and low dose responses in vivo: implications for radiation protection

International Nuclear Information System (INIS)

Mitchel, R.E.J.

2006-01-01

Full text: Radiation protection practices assume that cancer risk is linearly proportional to total dose, without a threshold, both for people with normal cancer risk and for people who may be genetically cancer prone. Mice heterozygous for the Tp 53 gene are cancer prone, and their increased risk from high doses was not different from Tp 53 normal mice. However, in either Tp 53 normal or heterozygous mice, a single low dose of low LET radiation given at low dose rate protected against both spontaneous and radiation-induced cancer by increasing tumor latency. Increased tumor latency without a cancer frequency change implies that low doses in vivo primarily slow the process of genomic instability, consistent with the elevated capacity for correct DSB rejoining seen in low dose exposed cells. The in vivo animal data indicates that, for low doses and low dose rates in both normal and cancer prone adult mice, risk does not increase linearly with dose, and dose thresholds for increased risk exist. Below those dose thresholds (which are influenced by Tp 53 function) overall risk is reduced below that of unexposed control mice, indicating that Dose Rate Effectiveness Factors (DREF) may approach infinity, rather than the current assumption of 2. However, as dose decreases, different tissues appear to have different thresholds at which detriment turns to protection, indicating that individual tissue weighting factors (Wt) are also not constant, but vary from positive values to zero with decreasing dose. Measurements of Relative Biological Effect between high and low LET radiations are used to establish radiation weighting factors (Wr) used in radiation protection, and these are also assumed to be constant with dose. However, since the risk from an exposure to low LET radiation is not constant with dose, it would seem unlikely that radiation-weighting factors for high LET radiation are actually constant at low dose and dose rate

3D delivered dose assessment using a 4DCT-based motion model

Energy Technology Data Exchange (ETDEWEB)

Cai, Weixing; Hurwitz, Martina H.; Williams, Christopher L.; Dhou, Salam; Berbeco, Ross I.; Mishra, Pankaj, E-mail: wcai@lroc.harvard.edu, E-mail: jhlewis@lroc.harvard.edu; Lewis, John H., E-mail: wcai@lroc.harvard.edu, E-mail: jhlewis@lroc.harvard.edu [Brigham and Women’s Hospital, Dana-Farber Cancer Institute and Harvard Medical School, Boston, Massachusetts 02115 (United States); Seco, Joao [Francis H. Burr Proton Therapy Center, Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02115 (United States)

2015-06-15

Purpose: The purpose of this work is to develop a clinically feasible method of calculating actual delivered dose distributions for patients who have significant respiratory motion during the course of stereotactic body radiation therapy (SBRT). Methods: A novel approach was proposed to calculate the actual delivered dose distribution for SBRT lung treatment. This approach can be specified in three steps. (1) At the treatment planning stage, a patient-specific motion model is created from planning 4DCT data. This model assumes that the displacement vector field (DVF) of any respiratory motion deformation can be described as a linear combination of some basis DVFs. (2) During the treatment procedure, 2D time-varying projection images (either kV or MV projections) are acquired, from which time-varying “fluoroscopic” 3D images of the patient are reconstructed using the motion model. The DVF of each timepoint in the time-varying reconstruction is an optimized linear combination of basis DVFs such that the 2D projection of the 3D volume at this timepoint matches the projection image. (3) 3D dose distribution is computed for each timepoint in the set of 3D reconstructed fluoroscopic images, from which the total effective 3D delivered dose is calculated by accumulating deformed dose distributions. This approach was first validated using two modified digital extended cardio-torso (XCAT) phantoms with lung tumors and different respiratory motions. The estimated doses were compared to the dose that would be calculated for routine 4DCT-based planning and to the actual delivered dose that was calculated using “ground truth” XCAT phantoms at all timepoints. The approach was also tested using one set of patient data, which demonstrated the application of our method in a clinical scenario. Results: For the first XCAT phantom that has a mostly regular breathing pattern, the errors in 95% volume dose (D95) are 0.11% and 0.83%, respectively for 3D fluoroscopic images

3D delivered dose assessment using a 4DCT-based motion model

International Nuclear Information System (INIS)

Cai, Weixing; Hurwitz, Martina H.; Williams, Christopher L.; Dhou, Salam; Berbeco, Ross I.; Mishra, Pankaj; Lewis, John H.; Seco, Joao

2015-01-01

Purpose: The purpose of this work is to develop a clinically feasible method of calculating actual delivered dose distributions for patients who have significant respiratory motion during the course of stereotactic body radiation therapy (SBRT). Methods: A novel approach was proposed to calculate the actual delivered dose distribution for SBRT lung treatment. This approach can be specified in three steps. (1) At the treatment planning stage, a patient-specific motion model is created from planning 4DCT data. This model assumes that the displacement vector field (DVF) of any respiratory motion deformation can be described as a linear combination of some basis DVFs. (2) During the treatment procedure, 2D time-varying projection images (either kV or MV projections) are acquired, from which time-varying “fluoroscopic” 3D images of the patient are reconstructed using the motion model. The DVF of each timepoint in the time-varying reconstruction is an optimized linear combination of basis DVFs such that the 2D projection of the 3D volume at this timepoint matches the projection image. (3) 3D dose distribution is computed for each timepoint in the set of 3D reconstructed fluoroscopic images, from which the total effective 3D delivered dose is calculated by accumulating deformed dose distributions. This approach was first validated using two modified digital extended cardio-torso (XCAT) phantoms with lung tumors and different respiratory motions. The estimated doses were compared to the dose that would be calculated for routine 4DCT-based planning and to the actual delivered dose that was calculated using “ground truth” XCAT phantoms at all timepoints. The approach was also tested using one set of patient data, which demonstrated the application of our method in a clinical scenario. Results: For the first XCAT phantom that has a mostly regular breathing pattern, the errors in 95% volume dose (D95) are 0.11% and 0.83%, respectively for 3D fluoroscopic images

Accelerating an Ordered-Subset Low-Dose X-Ray Cone Beam Computed Tomography Image Reconstruction with a Power Factor and Total Variation Minimization.

Science.gov (United States)

Huang, Hsuan-Ming; Hsiao, Ing-Tsung

2016-01-01

In recent years, there has been increased interest in low-dose X-ray cone beam computed tomography (CBCT) in many fields, including dentistry, guided radiotherapy and small animal imaging. Despite reducing the radiation dose, low-dose CBCT has not gained widespread acceptance in routine clinical practice. In addition to performing more evaluation studies, developing a fast and high-quality reconstruction algorithm is required. In this work, we propose an iterative reconstruction method that accelerates ordered-subsets (OS) reconstruction using a power factor. Furthermore, we combine it with the total-variation (TV) minimization method. Both simulation and phantom studies were conducted to evaluate the performance of the proposed method. Results show that the proposed method can accelerate conventional OS methods, greatly increase the convergence speed in early iterations. Moreover, applying the TV minimization to the power acceleration scheme can further improve the image quality while preserving the fast convergence rate.

A comparison of the effects of 2 doses of soy protein or casein on serum lipids, serum lipoproteins, and plasma total homocysteine in hypercholesterolemic subjects.

Science.gov (United States)

Tonstad, Serena; Smerud, Knut; Høie, Lars

2002-07-01

Studies have shown that soy protein reduces some atherogenic lipid and lipoprotein concentrations, although lipoprotein(a) concentrations may be increased. The dose response of soy protein has not been established; neither has its effect on plasma total homocysteine. Our objective was to evaluate the effect of 2 doses of soy protein on lipid, lipoprotein, and homocysteine concentrations. Four to 24 wk after being instructed to consume a lipid-lowering diet, 130 men and women with LDL-cholesterol concentrations > or = 4 mmol/L were studied during a parallel group trial in which 4 interventions were assigned randomly. Thirty grams isolated soy protein (ISP) and 10 g cotyledon fiber or 50 g ISP and 16.6 g cotyledon fiber or equivalent doses of casein and cellulose were consumed daily as a beverage for 16 wk. When the 2 groups who consumed ISP were compared with the 2 groups who consumed casein, the differences in the net changes from baseline to week 16 in the concentrations of LDL cholesterol and plasma total homocysteine were -0.26 mmol/L (95% CI: -0.43, -0.09 mmol/L; P = 0.01) and -0.8 micromol/L (-1.4, -0.2 micromol/L; P = 0.005), respectively. The effect of the ISP dose was not significant. There were no significant differences between the 2 ISP and the 2 casein groups in changes in lipoprotein(a), HDL-cholesterol, or triacylglycerol concentrations. Adding 30-50 g soy protein/d to a lipid-lowering diet significantly reduced LDL-cholesterol concentrations without increasing lipoprotein(a) concentrations. Plasma total homocysteine concentrations also decreased, suggesting a novel, possibly antiatherosclerotic effect.

Automated extraction of radiation dose information from CT dose report images.

Science.gov (United States)

Li, Xinhua; Zhang, Da; Liu, Bob

2011-06-01

The purpose of this article is to describe the development of an automated tool for retrieving texts from CT dose report images. Optical character recognition was adopted to perform text recognitions of CT dose report images. The developed tool is able to automate the process of analyzing multiple CT examinations, including text recognition, parsing, error correction, and exporting data to spreadsheets. The results were precise for total dose-length product (DLP) and were about 95% accurate for CT dose index and DLP of scanned series.

Dose measurements in mammography

International Nuclear Information System (INIS)

Kainberger, F.; Kallinger, W.

1977-01-01

Dose measurements at the mamma during mammography were carried out in the form of direct measurement with thermoluminescent dosimetry. Measurement was done for the in- and outcoming doses at the mamma, the dose exposure of the sternal region and the scattered rays above the symphysis, the latter as parameter for the genetic radiation exposure. As expected, the dose of the smooth radiation used for mammography showed a strong decrease at the outcome point in comparison with the income point. Surprisingly high was the scattered radiation in the sternal region. A corresponding protection by lead plates could be taken into consideration. Extremely low is the scattered radiation above the symphysis. Even measurements with the very sensitive calcium fluoride dosimeters did not reveal any practically important dose in the symphysis region. Most measurement values remained below the determinable dose of 0.3mR. Some maximal values varied in the range of 3-1 mR. (orig.) [de

Radiation dose in cardiac SPECT/CT: An estimation of SSDE and effective dose

International Nuclear Information System (INIS)

Abdollahi, Hamid; Shiri, Isaac; Salimi, Yazdan; Sarebani, Maghsoud; Mehdinia, Reza; Deevband, Mohammad Reza; Mahdavi, Seied Rabi; Sohrabi, Ahmad; Bitarafan-Rajabi, Ahmad

2016-01-01

Aims: The dose levels for Computed Tomography (CT) localization and attenuation correction of Single Photon Emission Computed Tomography (SPECT) are limited and reported as Volume Computed Tomography Dose Index (CTDIvol) and Dose-Length Product (DLP). This work presents CT dose estimation from Cardiac SPECT/CT based on new American Association of Physicists in Medicine (AAPM) Size Specific Dose Estimation (SSDE) parameter, effective dose, organ doses and also emission dose from nuclear issue. Material and methods: Myocardial perfusion SPECT/CT for 509 patients was included in the study. SSDE, effective dose and organ dose were calculated using AAPM guideline and Impact-Dose software. Data were analyzed using R and SPSS statistical software. Spearman-Pearson correlation test and linear regression models were used for finding correlations and relationships among parameters. Results: The mean CTDIvol was 1.34 mGy ± 0.19 and the mean SSDE was 1.7 mGy ± 0.16. The mean ± SD of effective dose from emission, CT and total dose were 11.5 ± 1.4, 0.49 ± 0.11 and 12.67 ± 1.73 (mSv) respectively. The mean ± SD of effective dose from emission, CT and total dose were 11.5 ± 1.4, 0.49 ± 0.11 and 12.67 ± 1.73 (mSv) respectively. The spearman test showed that correlation between body size and organ doses is significant except thyroid and red bone marrow. CTDIvol was strongly dependent on patient size, but SSDE was not. Emission dose was strongly dependent on patient weight, but its dependency was lower to effective diameter. Conclusion: The dose parameters including CTDIvol, DLP, SSDE, effective dose values reported here are very low and below the reference level. This data suggest that appropriate CT acquisition parameters in SPECT/CT localization and attenuation correction are very beneficial for patients and lowering cancer risks.

Radiation dose in cardiac SPECT/CT: An estimation of SSDE and effective dose

Energy Technology Data Exchange (ETDEWEB)

Abdollahi, Hamid, E-mail: Hamid_rbp@yahoo.com [Department of Medical Physics, School of Medicine, Iran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Shiri, Isaac [Department of Medical Physics, School of Medicine, Iran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Salimi, Yazdan [Biomedical Engineering and Medical Physics Department, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran (Iran, Islamic Republic of); Sarebani, Maghsoud; Mehdinia, Reza [Department of Medical Physics, School of Medicine, Iran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Deevband, Mohammad Reza [Biomedical Engineering and Medical Physics Department, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran (Iran, Islamic Republic of); Mahdavi, Seied Rabi [Department of Medical Physics, School of Medicine, Iran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Radiation Biology Research Center, Iran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Sohrabi, Ahmad [Department of Biostatistics, School of Public Health, Iran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Bitarafan-Rajabi, Ahmad, E-mail: bitarafan@hotmail.com [Department of Medical Physics, School of Medicine, Iran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Department of Nuclear Medicine, Rajaei Cardiovascular, Medical and Research Center, Iran University of Medical Sciences, Tehran (Iran, Islamic Republic of)

2016-12-15

Aims: The dose levels for Computed Tomography (CT) localization and attenuation correction of Single Photon Emission Computed Tomography (SPECT) are limited and reported as Volume Computed Tomography Dose Index (CTDIvol) and Dose-Length Product (DLP). This work presents CT dose estimation from Cardiac SPECT/CT based on new American Association of Physicists in Medicine (AAPM) Size Specific Dose Estimation (SSDE) parameter, effective dose, organ doses and also emission dose from nuclear issue. Material and methods: Myocardial perfusion SPECT/CT for 509 patients was included in the study. SSDE, effective dose and organ dose were calculated using AAPM guideline and Impact-Dose software. Data were analyzed using R and SPSS statistical software. Spearman-Pearson correlation test and linear regression models were used for finding correlations and relationships among parameters. Results: The mean CTDIvol was 1.34 mGy ± 0.19 and the mean SSDE was 1.7 mGy ± 0.16. The mean ± SD of effective dose from emission, CT and total dose were 11.5 ± 1.4, 0.49 ± 0.11 and 12.67 ± 1.73 (mSv) respectively. The mean ± SD of effective dose from emission, CT and total dose were 11.5 ± 1.4, 0.49 ± 0.11 and 12.67 ± 1.73 (mSv) respectively. The spearman test showed that correlation between body size and organ doses is significant except thyroid and red bone marrow. CTDIvol was strongly dependent on patient size, but SSDE was not. Emission dose was strongly dependent on patient weight, but its dependency was lower to effective diameter. Conclusion: The dose parameters including CTDIvol, DLP, SSDE, effective dose values reported here are very low and below the reference level. This data suggest that appropriate CT acquisition parameters in SPECT/CT localization and attenuation correction are very beneficial for patients and lowering cancer risks.

Immune reactivity after high-dose irradiation

International Nuclear Information System (INIS)

Gassmann, W.; Wottge, H.U.; von Kolzynski, M.; Mueller-Ruchholtz, W.

1986-01-01

Immune reactivity after total-body irradiation was investigated in rats using skin graft rejection as the indicator system. After sublethal irradiation with 10.5 Gy (approximately 50% lethality/6 weeks) the rejection of major histocompatibility complex allogeneic skin grafts was delayed significantly compared with nonirradiated control animals (28 versus 6.5 days). In contrast, skin grafts were rejected after 7.5 days in sublethally irradiated animals and 7 days in lethally irradiated animals if additional skin donor type alloantigens--namely, irradiated bone marrow cells--were given i.v. either simultaneously or with a delay of not more than 24 hr after the above conditioning regimen. These reactions were alloantigen-specific. They were observed in six different strain combinations with varying donors and recipients. Starting on day 2 after irradiation, i.v. injection of bone marrow gradually lost its effectivity and skin grafts were no longer rejected with uniform rapidity; skin donor marrow given on days 4 or 8 did not accelerate skin graft rejection at all. These data show that for approximately 1-2 days after high-dose total-body irradiation rats are still capable of starting a vigorous immune reaction against i.v.-injected alloantigens. The phenomenon of impaired rejection of skin grafted immediately after high-dose irradiation appears to result from the poor accessibility of skin graft alloantigens during the early postirradiation phase when vascularization of the grafted skin is insufficient

Xerostomia after radiotherapy. What matters - mean total dose or dose to each parotid gland?

International Nuclear Information System (INIS)

Tribius, S.; Sommer, J.; Prosch, C.; Bajrovic, A.; Kruell, A.; Petersen, C.; Muenscher, A.; Blessmann, M.; Todorovic, M.; Tennstedt, P.

2013-01-01

Purpose: Xerostomia is a debilitating side effect of radiotherapy in patients with head and neck cancer. We undertook a prospective study of the effect on xerostomia and outcomes of sparing one or both parotid glands during radiotherapy for patients with squamous cell carcinoma of the head and neck. Methods and materials: Patients with locally advanced squamous cell carcinoma of the head and neck received definitive (70 Gy in 2 Gy fractions) or adjuvant (60-66 Gy in 2 Gy fractions) curative-intent radiotherapy using helical tomotherapy with concurrent chemotherapy if appropriate. Group A received < 26 Gy to the left and right parotids and group B received < 26 Gy to either parotid. Results: The study included 126 patients; 114 (55 in group A and 59 in group B) had follow-up data. There were no statistically significant differences between groups in disease stage. Xerostomia was significantly reduced in group A vs. group B (p = 0.0381). Patients in group A also had significantly less dysphagia. Relapse-free and overall survival were not compromised in group A: 2-year relapse-free survival was 86% vs. 72% in group B (p = 0.361); 2-year overall survival was 88% and 76%, respectively (p = 0.251). Conclusion: This analysis suggests that reducing radiotherapy doses to both parotid glands to < 26 Gy can reduce xerostomia and dysphagia significantly without compromising survival. Sparing both parotids while maintaining target volume coverage and clinical outcome should be the treatment goal and reporting radiotherapy doses delivered to the individual parotids should be standard practice. (orig.)

Xerostomia after radiotherapy. What matters - mean total dose or dose to each parotid gland?

Energy Technology Data Exchange (ETDEWEB)

Tribius, S.; Sommer, J.; Prosch, C.; Bajrovic, A.; Kruell, A.; Petersen, C. [University Medical Center Hamburg-Eppendorf, Hamburg (Germany). Dept. of Radiation Oncology; Muenscher, A. [University Medical Center Hamburg-Eppendorf, Hamburg (Germany). Dept. of Otorhinolaryngology and Head and Neck Surgery; Blessmann, M. [University Medical Center Hamburg-Eppendorf, Hamburg (Germany). Dept. of Oral and Maxillofacial Surgery; Todorovic, M. [University Medical Center Hamburg-Eppendorf, Hamburg (Germany). Dept. of Medical Physics; Tennstedt, P. [University Medical Center Hamburg-Eppendorf, Hamburg (Germany). Martini-Clinic, Prostate Cancer Center

2013-03-15

Purpose: Xerostomia is a debilitating side effect of radiotherapy in patients with head and neck cancer. We undertook a prospective study of the effect on xerostomia and outcomes of sparing one or both parotid glands during radiotherapy for patients with squamous cell carcinoma of the head and neck. Methods and materials: Patients with locally advanced squamous cell carcinoma of the head and neck received definitive (70 Gy in 2 Gy fractions) or adjuvant (60-66 Gy in 2 Gy fractions) curative-intent radiotherapy using helical tomotherapy with concurrent chemotherapy if appropriate. Group A received < 26 Gy to the left and right parotids and group B received < 26 Gy to either parotid. Results: The study included 126 patients; 114 (55 in group A and 59 in group B) had follow-up data. There were no statistically significant differences between groups in disease stage. Xerostomia was significantly reduced in group A vs. group B (p = 0.0381). Patients in group A also had significantly less dysphagia. Relapse-free and overall survival were not compromised in group A: 2-year relapse-free survival was 86% vs. 72% in group B (p = 0.361); 2-year overall survival was 88% and 76%, respectively (p = 0.251). Conclusion: This analysis suggests that reducing radiotherapy doses to both parotid glands to < 26 Gy can reduce xerostomia and dysphagia significantly without compromising survival. Sparing both parotids while maintaining target volume coverage and clinical outcome should be the treatment goal and reporting radiotherapy doses delivered to the individual parotids should be standard practice. (orig.)

Dose fractionation theorem in 3-D reconstruction (tomography)

Energy Technology Data Exchange (ETDEWEB)

Glaeser, R.M. [Lawrence Berkeley National Lab., CA (United States)

1997-02-01

It is commonly assumed that the large number of projections for single-axis tomography precludes its application to most beam-labile specimens. However, Hegerl and Hoppe have pointed out that the total dose required to achieve statistical significance for each voxel of a computed 3-D reconstruction is the same as that required to obtain a single 2-D image of that isolated voxel, at the same level of statistical significance. Thus a statistically significant 3-D image can be computed from statistically insignificant projections, as along as the total dosage that is distributed among these projections is high enough that it would have resulted in a statistically significant projection, if applied to only one image. We have tested this critical theorem by simulating the tomographic reconstruction of a realistic 3-D model created from an electron micrograph. The simulations verify the basic conclusions of high absorption, signal-dependent noise, varying specimen contrast and missing angular range. Furthermore, the simulations demonstrate that individual projections in the series of fractionated-dose images can be aligned by cross-correlation because they contain significant information derived from the summation of features from different depths in the structure. This latter information is generally not useful for structural interpretation prior to 3-D reconstruction, owing to the complexity of most specimens investigated by single-axis tomography. These results, in combination with dose estimates for imaging single voxels and measurements of radiation damage in the electron microscope, demonstrate that it is feasible to use single-axis tomography with soft X-ray microscopy of frozen-hydrated specimens.

Dose fractionation theorem in 3-D reconstruction (tomography)

International Nuclear Information System (INIS)

Glaeser, R.M.

1997-01-01

It is commonly assumed that the large number of projections for single-axis tomography precludes its application to most beam-labile specimens. However, Hegerl and Hoppe have pointed out that the total dose required to achieve statistical significance for each voxel of a computed 3-D reconstruction is the same as that required to obtain a single 2-D image of that isolated voxel, at the same level of statistical significance. Thus a statistically significant 3-D image can be computed from statistically insignificant projections, as along as the total dosage that is distributed among these projections is high enough that it would have resulted in a statistically significant projection, if applied to only one image. We have tested this critical theorem by simulating the tomographic reconstruction of a realistic 3-D model created from an electron micrograph. The simulations verify the basic conclusions of high absorption, signal-dependent noise, varying specimen contrast and missing angular range. Furthermore, the simulations demonstrate that individual projections in the series of fractionated-dose images can be aligned by cross-correlation because they contain significant information derived from the summation of features from different depths in the structure. This latter information is generally not useful for structural interpretation prior to 3-D reconstruction, owing to the complexity of most specimens investigated by single-axis tomography. These results, in combination with dose estimates for imaging single voxels and measurements of radiation damage in the electron microscope, demonstrate that it is feasible to use single-axis tomography with soft X-ray microscopy of frozen-hydrated specimens

Baixas doses de misoprostol vaginal (12,5 versus 25 mcg para indução do parto a termo Low-dose vaginal misoprostol (12.5 versus 25 µg for induction of labor at term

Directory of Open Access Journals (Sweden)

Francisco Airton Rangel Filho

2007-12-01

Full Text Available OBJETIVO: comparar a efetividade de baixas doses de misoprostol vaginal (12,5 versus 25 mcg para indução do trabalho de parto. MÉTODOS: ensaio clínico controlado, randomizado, duplo-cego, realizado entre maio de 2005 e abril de 2006. Foram incluídas 62 gestantes com gravidez a termo, membranas íntegras, que necessitaram de indução do parto. Foi administrado 25 mcg (32 ou 12,5 mcg de misoprostol (30, a cada quatro horas, até, no máximo, oito doses. Estudaram-se o tipo de parto, tempo entre o início da indução e o parto, complicações perinatais e efeitos maternos adversos. As variáveis de controle foram idades materna e gestacional, paridade e índice de Bishop. Os testes estatísticos utilizados foram cálculos de médias, desvios padrão e teste t de Student (variáveis numéricas contínuas, c² (variáveis categóricas e Mann-Whitney (variáveis discretas. RESULTADOS: não houve diferença significante entre o Grupo de 12,5 e 25 mcg em relação ao intervalo de tempo entre a primeira dose e o parto (1.524 minutos versus 1.212 minutos, p=0,3, na freqüência de partos vaginais (70 versus 71,8%, p=0,7, no escore de Apgar inferior a sete ao quinto minuto (3,3 versus 6,25%, p=0,5 e na freqüência de taquissistolia (3,3 versus 6,2%, p=0,5. A média da dose total administrada de misoprostol foi significativamente maior no Grupo de 25 mcg (40 versus 61,2 mcg, p=0,03. CONCLUSÕES: misoprostol vaginal na dose de 12,5 mcg foi eficiente, com efeitos colaterais semelhante, à dose de 25 mcg de misoprostol vaginal, para indução do parto a termo.PURPOSE: to compare the effectiveness of low doses of vaginal misoprostol (12.5 versus 25 µg for induction of labor. METHODS: a double-blind, randomized, controlled clinical trial was performed in Santa Casa de Misericórdia de Sobral, from May 2005 to April 2006. Sixty-two term pregnant women, with intact membranes and with indication for labor induction, were included. They randomly received 25

Level and distribution of the radiation dose to the population from a mammography screening programme in New Zealand

Energy Technology Data Exchange (ETDEWEB)

Bulling, S.M.; Nicoll, J.J. [Otago Univ., Dunedin (New Zealand). Dept. of Physics

1995-12-31

The Otago Southland Breast Screening Programme offers biennial mammography to 19,000 eligible women on the South Island of New Zealand. A Quality Assurance programme ensures that international performance standards are met, in particular the radiation dose for a mammogram of 5 cm CIRS-X phantom is 1.7 mGy and careful retake analysis undertaken. This however does not reveal the absorbed dose received by individuals, nor how this varies between individuals. Machine parameters and compressed breast thickness for each film were recorded for 310 women who attended one centre during the three months ending February 1993 and absorbed doses calculated using Monte Carlo data. The mean compressed breast thickness for the 310 women was 4.9 cm, doses received for individual films ranged from 0.7 to 8.5 mGy while patient total doses were in the range 4 to 29 mGy with 75% of women receiving a dose of 7.1 mGy or less. (Author).

The effect of total body irradiation dose and chronic graft-versus-host disease on leukaemic relapse after allogeneic bone marrow transplantation

Energy Technology Data Exchange (ETDEWEB)

Frassoni, F; Bacigalupo, A [Ospedale San Martino (Italy). Centro Trapianti Midollo Osseo; Scarpati, D [Univ. di Genova (Italy). Ist. di Radiologia; and others

1989-10-01

One-hundred and five patients undergoing allo-geneic bone marrow transplantation (BMT) for acute myeloid leukaemia (AML) (n=61) and chronic myeloid leukaemia (n=44) were analysed for risk factors associated with relapse. All patients received marrow from an HLA identical sibling after preparation with cyclophosphamide 120 mg/kg and total body irradiation (TBI) 330 cGy on each of the three days prior to transplantation. A multivariate Cox analysis indicated that a lower TBI dose (less than 990 cGy) was the most significant factor associated with relapse and the second most important factor associated with recurrence of leukaemia was the absence of chronic graft-versus-host-disease (cGvHD). Actuarial relapse incidence was 62%, 28% and 18% for patients with no, limited or extensive chronic GvHD respectively. However, chronic GvHD had no significant impact on survival. Combined stratification for TBI dose and cGvHD showed that the dose effect of TBI on relapse was evident both in patients with and without cGvHD. Chronic GvHD influenced the risk of relapse only in patients receiving less than 990 cGy. These results suggest that a higher dose of TBI, within this schedule, produced long-term disease-free survival in the majority of AMLs and CMLs. Minor radiobiological side effects were experienced, but a small reduction of the dose may significantly increase the risk of relapse. (author).

The effect of total body irradiation dose and chronic graft-versus-host disease on leukaemic relapse after allogeneic bone marrow transplantation

International Nuclear Information System (INIS)

Frassoni, F.; Bacigalupo, A.; Scarpati, D.

1989-01-01

One-hundred and five patients undergoing allo-geneic bone marrow transplantation (BMT) for acute myeloid leukaemia (AML) (n=61) and chronic myeloid leukaemia (n=44) were analysed for risk factors associated with relapse. All patients received marrow from an HLA identical sibling after preparation with cyclophosphamide 120 mg/kg and total body irradiation (TBI) 330 cGy on each of the three days prior to transplantation. A multivariate Cox analysis indicated that a lower TBI dose (less than 990 cGy) was the most significant factor associated with relapse and the second most important factor associated with recurrence of leukaemia was the absence of chronic graft-versus-host-disease (cGvHD). Actuarial relapse incidence was 62%, 28% and 18% for patients with no, limited or extensive chronic GvHD respectively. However, chronic GvHD had no significant impact on survival. Combined stratification for TBI dose and cGvHD showed that the dose effect of TBI on relapse was evident both in patients with and without cGvHD. Chronic GvHD influenced the risk of relapse only in patients receiving less than 990 cGy. These results suggest that a higher dose of TBI, within this schedule, produced long-term disease-free survival in the majority of AMLs and CMLs. Minor radiobiological side effects were experienced, but a small reduction of the dose may significantly increase the risk of relapse. (author)

Dose-rate dependent stochastic effects in radiation cell-survival models

International Nuclear Information System (INIS)

Sachs, R.K.; Hlatky, L.R.

1990-01-01

When cells are subjected to ionizing radiation the specific energy rate (microscopic analog of dose-rate) varies from cell to cell. Within one cell, this rate fluctuates during the course of time; a crossing of a sensitive cellular site by a high energy charged particle produces many ionizations almost simultaneously, but during the interval between events no ionizations occur. In any cell-survival model one can incorporate the effect of such fluctuations without changing the basic biological assumptions. Using stochastic differential equations and Monte Carlo methods to take into account stochastic effects we calculated the dose-survival rfelationships in a number of current cell survival models. Some of the models assume quadratic misrepair; others assume saturable repair enzyme systems. It was found that a significant effect of random fluctuations is to decrease the theoretically predicted amount of dose-rate sparing. In the limit of low dose-rates neglecting the stochastic nature of specific energy rates often leads to qualitatively misleading results by overestimating the surviving fraction drastically. In the opposite limit of acute irradiation, analyzing the fluctuations in rates merely amounts to analyzing fluctuations in total specific energy via the usual microdosimetric specific energy distribution function, and neglecting fluctuations usually underestimates the surviving fraction. The Monte Carlo methods interpolate systematically between the low dose-rate and high dose-rate limits. As in other approaches, the slope of the survival curve at low dose-rates is virtually independent of dose and equals the initial slope of the survival curve for acute radiation. (orig.)

Analgesic and sedative effects of perioperative gabapentin in total knee arthroplasty A randomized, double-blind, placebo-controlled, dose-finding study

DEFF Research Database (Denmark)

Lunn, Troels Haxholdt; Husted, Henrik; Laursen, Mogens Berg

2015-01-01

(1:1:1) to either gabapentin 1300 mg/d (group A), gabapentin 900 mg/d (group B), or placebo (group C) daily from 2 hours preoperatively to postoperative day 6 in addition to a standardized multimodal analgesic regime. The primary outcome was pain upon ambulation 24 hours after surgery......Gabapentin has shown acute postoperative analgesic effects, but the optimal dose and procedure-specific benefits vs harm have not been clarified. In this randomized, double-blind, placebo-controlled dose-finding study, 300 opioid-naive patients scheduled for total knee arthroplasty were randomized......, and the secondary outcome was sedation 6 hours after surgery. Other outcomes were overall pain during well-defined mobilizations and at rest and sedation during the first 48 hours and from days 2-6, morphine use, anxiety, depression, sleep quality, and nausea, vomiting, dizziness, concentration difficulty, headache...

Development of Real-Time Measurement of Effective Dose for High Dose Rate Neutron Fields

CERN Document Server

Braby, L A; Reece, W D

2003-01-01

Studies of the effects of low doses of ionizing radiation require sources of radiation which are well characterized in terms of the dose and the quality of the radiation. One of the best measures of the quality of neutron irradiation is the dose mean lineal energy. At very low dose rates this can be determined by measuring individual energy deposition events, and calculating the dose mean of the event size. However, at the dose rates that are normally required for biology experiments, the individual events can not be separated by radiation detectors. However, the total energy deposited in a specified time interval can be measured. This total energy has a random variation which depends on the size of the individual events, so the dose mean lineal energy can be calculated from the variance of repeated measurements of the energy deposited in a fixed time. We have developed a specialized charge integration circuit for the measurement of the charge produced in a small ion chamber in typical neutron irradiation exp...

Carbohydrate-to-insulin ratio is estimated from 300-400 divided by total daily insulin dose in type 1 diabetes patients who use the insulin pump.

Science.gov (United States)

Kuroda, Akio; Yasuda, Tetsuyuki; Takahara, Mitsuyoshi; Sakamoto, Fumie; Kasami, Ryuichi; Miyashita, Kazuyuki; Yoshida, Sumiko; Kondo, Eri; Aihara, Ken-ichi; Endo, Itsuro; Matsuoka, Taka-aki; Kaneto, Hideaki; Matsumoto, Toshio; Shimomura, Iichiro; Matsuhisa, Munehide

2012-11-01

To optimize insulin dose using insulin pump, basal and bolus insulin doses are widely calculated from total daily insulin dose (TDD). It is recommended that total daily basal insulin dose (TBD) is 50% of TDD and that the carbohydrate-to-insulin ratio (CIR) equals 500 divided by TDD. We recently reported that basal insulin requirement is approximately 30% of TDD. We therefore investigated CIR after adjustment of the proper basal insulin rate. Forty-five Japanese patients with type 1 diabetes were investigated during several weeks of hospitalization. The patients were served standard diabetes meals (25-30 kcal/kg of ideal body weight). Each meal omission was done to confirm basal insulin rate. Target blood glucose level was set at 100 and 150 mg/dL before and 2 h after each meal, respectively. After the basal insulin rate was fixed and target blood glucose levels were achieved, TBD, CIR, TDD, and their products were determined. Mean (±SD) blood glucose levels before and 2 h after meals were 121±47 and 150±61 mg/dL, respectively. TDD was 31.5±9.0 U, and TBD was 27.0±6.5% of TDD. CIR×TDD of breakfast was significantly lower than those of lunch and supper (288±73 vs. 408±92 and 387±83, respectively; Plunch and supper in type 1 diabetes patients. These results indicate that the insulin dose has been underestimated by using previously established calculations.

Total lymphoid irradiation

International Nuclear Information System (INIS)

Sutherland, D.E.; Ferguson, R.M.; Simmons, R.L.; Kim, T.H.; Slavin, S.; Najarian, J.S.

1983-01-01

Total lymphoid irradiation by itself can produce sufficient immunosuppression to prolong the survival of a variety of organ allografts in experimental animals. The degree of prolongation is dose-dependent and is limited by the toxicity that occurs with higher doses. Total lymphoid irradiation is more effective before transplantation than after, but when used after transplantation can be combined with pharmacologic immunosuppression to achieve a positive effect. In some animal models, total lymphoid irradiation induces an environment in which fully allogeneic bone marrow will engraft and induce permanent chimerism in the recipients who are then tolerant to organ allografts from the donor strain. If total lymphoid irradiation is ever to have clinical applicability on a large scale, it would seem that it would have to be under circumstances in which tolerance can be induced. However, in some animal models graft-versus-host disease occurs following bone marrow transplantation, and methods to obviate its occurrence probably will be needed if this approach is to be applied clinically. In recent years, patient and graft survival rates in renal allograft recipients treated with conventional immunosuppression have improved considerably, and thus the impetus to utilize total lymphoid irradiation for its immunosuppressive effect alone is less compelling. The future of total lymphoid irradiation probably lies in devising protocols in which maintenance immunosuppression can be eliminated, or nearly eliminated, altogether. Such protocols are effective in rodents. Whether they can be applied to clinical transplantation remains to be seen

Simulation and measurement of total ionizing dose radiation induced image lag increase in pinned photodiode CMOS image sensors

Energy Technology Data Exchange (ETDEWEB)

Liu, Jing [School of Materials Science and Engineering, Xiangtan University, Hunan (China); State Key Laboratory of Intense Pulsed Irradiation Simulation and Effect, Northwest Institute of Nuclear Technology, P.O.Box 69-10, Xi’an (China); Chen, Wei, E-mail: chenwei@nint.ac.cn [State Key Laboratory of Intense Pulsed Irradiation Simulation and Effect, Northwest Institute of Nuclear Technology, P.O.Box 69-10, Xi’an (China); Wang, Zujun, E-mail: wangzujun@nint.ac.cn [State Key Laboratory of Intense Pulsed Irradiation Simulation and Effect, Northwest Institute of Nuclear Technology, P.O.Box 69-10, Xi’an (China); Xue, Yuanyuan; Yao, Zhibin; He, Baoping; Ma, Wuying; Jin, Junshan; Sheng, Jiangkun; Dong, Guantao [State Key Laboratory of Intense Pulsed Irradiation Simulation and Effect, Northwest Institute of Nuclear Technology, P.O.Box 69-10, Xi’an (China)

2017-06-01

This paper presents an investigation of total ionizing dose (TID) induced image lag sources in pinned photodiodes (PPD) CMOS image sensors based on radiation experiments and TCAD simulation. The radiation experiments have been carried out at the Cobalt −60 gamma-ray source. The experimental results show the image lag degradation is more and more serious with increasing TID. Combining with the TCAD simulation results, we can confirm that the junction of PPD and transfer gate (TG) is an important region forming image lag during irradiation. These simulations demonstrate that TID can generate a potential pocket leading to incomplete transfer.

A method for total body irradiation

International Nuclear Information System (INIS)

Yasukochi, Hiroshi; Higashi, Shizuka; Okuhata, Yoshitaka; Lee, Keiichi; Ishioka, Kuniaki; Murakami, Koji; Nagai, Jun; Kuniyasu, Yoshio

1988-01-01

In these two years, we have treated four infant patients of acute leukemia by Cobalt-60 total body irradiation and bone marrow transplantation. During total body irradiation, thermoluminescence dosimeters were attached to the skin of patients. For four patients, nine dosimetries were performed. Reliability of this method was examined by phantom experiment. Every irradiation for the patient per fraction was 2.4 Gy, that is, 60 cGy for each four positions, right decubitus A-P and PA directions and left decubitus A-P and PA directions under aseptic circumstances. Radiation dose was uniform by this technique for each patient, and average determined dose for surface of the patients was between 87 % and 106 % compared with the air dose of the center of aseptic space (wagon). As the result, we suggest that this method is suitable for the total body irradiation of acute leukemia of infant. (author)

Dynamic interactions between hydrogeological and exposure parameters in daily dose prediction under uncertainty and temporal variability

Energy Technology Data Exchange (ETDEWEB)

Kumar, Vikas, E-mail: vikas.kumar@urv.cat [Department of Chemical Engineering, Rovira i Virgili University, Tarragona 43007 (Spain); Barros, Felipe P.J. de [Sonny Astani Department of Civil and Environmental Engineering, University of Southern California, Los Angeles 90089, CA (United States); Schuhmacher, Marta [Department of Chemical Engineering, Rovira i Virgili University, Tarragona 43007 (Spain); Fernàndez-Garcia, Daniel; Sanchez-Vila, Xavier [Hydrogeology Group, Department of Geotechnical Engineering and Geosciences, University Politècnica de Catalunya-BarcelonaTech, Barcelona 08034 (Spain)

2013-12-15

Highlights: • Dynamic parametric interaction in daily dose prediction under uncertainty. • Importance of temporal dynamics associated with the dose. • Different dose experienced by different population cohorts as a function of time. • Relevance of uncertainty reduction in the input parameters shows temporal dynamism. -- Abstract: We study the time dependent interaction between hydrogeological and exposure parameters in daily dose predictions due to exposure of humans to groundwater contamination. Dose predictions are treated stochastically to account for an incomplete hydrogeological and geochemical field characterization, and an incomplete knowledge of the physiological response. We used a nested Monte Carlo framework to account for uncertainty and variability arising from both hydrogeological and exposure variables. Our interest is in the temporal dynamics of the total dose and their effects on parametric uncertainty reduction. We illustrate the approach to a HCH (lindane) pollution problem at the Ebro River, Spain. The temporal distribution of lindane in the river water can have a strong impact in the evaluation of risk. The total dose displays a non-linear effect on different population cohorts, indicating the need to account for population variability. We then expand the concept of Comparative Information Yield Curves developed earlier (see de Barros et al. [29]) to evaluate parametric uncertainty reduction under temporally variable exposure dose. Results show that the importance of parametric uncertainty reduction varies according to the temporal dynamics of the lindane plume. The approach could be used for any chemical to aid decision makers to better allocate resources towards reducing uncertainty.

Serum total homocystein, folate and vitamin B12 levels and their correlation with antipsychotic drug doses in adult male patients with chronic schizophrenia.

Science.gov (United States)

Eren, Esin; Yeğin, Ayşenur; Yilmaz, Necat; Herken, Hasan

2010-01-01

Elevated blood levels of homocysteine (hCY) have been associated with schizophrenic male patients. However, controversy remains regarding the association between lowered plasma folate and vitamin B12, hyperhomocysteinemia, and schizophrenia. Sixty-six (66) male patients with chronic schizophrenia were investigated to test the hypotheses that alterations in Hcy, folate, and vitamin B12 levels might be related to the antipsychotic drug doses used in treatment. Serum total homocysteine, folic acid, and vitamin B12 levels were determined by chemiluminescence methods in both patients and control subjects. The patients were grouped according to the antipsychotic drug doses used in their treatment. Patients had higher homocysteine levels but they did not differ from controls in terms of folate and vitamin B12 levels. On the other hand, only folate levels were negatively correlated in the patient group treated with higher therapeutic doses of chlorpromazine equivalents (> 400 mg/day) compared to the patient group with lower doses (< 400 mg/day). Our findings show that higher typical antipsychotic drugs may play a role as modifiying factor for folate metabolism in chronic schizoprenic male patients.

[Determination of total phthalates in perfume and their exposure assessment].

Science.gov (United States)

Zhao, Sihan; Wang, Zhengmeng; Deng, Hongxia; Duan, Jiahui; Wang, Jinyi; Liu, Shuhui

2017-12-08

A novel method for rapid screening of phthalates (PAEs) in perfumes was developed. The PAEs were hydrolyzed to phthalic acid (PA), and the PA in the acidified solution was extracted with tributyl phosphate (TBP) which was detected by high performance liquid chromatography-diode array detection (HPLC-DAD). Meanwhile exposure dose to PAEs was estimated by the percentage of a topically applied dose that permeates the skin. The parameters such as the concentration and volume of KOH, the volume of ethanol, hydrolysis time and temperature were employed to evaluate the hydrolysis efficiency of PAEs. The optimized hydrolysis conditions were 10 mL of 4 mol/L KOH, and 1 mL of ethanol at 80℃ for 20 min. The linear range of phthalic acid was 3-240 μmol/L with a good correlation coefficient ( R 2 =0.9991). The limits of detection (LOD) and quantification (LOQ) were 4.6 μmol/kg and 5.9 μmol/kg, respectively. The recoveries varied from 83.4% to 92.7% with relative standard deviations equal to or lower than 6.8%( n =5). A total of 35 perfume samples were determined, and the contents of total PAEs were found in the range of perfumes. The method is simple and reliable, and has a wide range of applicability. It can be used as a new choice for the detection of PAEs in perfume.

Total-dose radiation-induced degradation of thin film ferroelectric capacitors

International Nuclear Information System (INIS)

Schwank, J.R.; Nasby, R.D.; Miller, S.L.; Rodgers, M.S.; Dressendorfer, P.V.

1990-01-01

Thin film PbZr y Ti 1-y O 3 (PZT) ferroelectric memories offer the potential for radiation-hardened, high-speed nonvolatile memories with good retention and fatigue properties. In this paper we explore in detail the radiation hardness of PZT ferroelectric capacitors. Ferroelectric capacitors were irradiated using x-ray and Co-60 sources to dose levels up to 16 Mrad(Si). The capacitors were characterized for their memory properties both before and after irradiation. The radiation hardness was process dependent. Three out of four processes resulted in capacitors that showed less than 30% radiation-induced degradation in retained polarization charge and remanent polarization after irradiating to 16 Mrad(Si). On the other hand, one of the processes showed significant radiation-induced degradation in retained polarization charge and remanent polarization at dose levels above 1 Mrad(Si). The decrease in retained polarization charge appears to be due to an alteration of the switching characteristics of the ferroelectric due to changes in the internal fields. The radiation-induced degradation is recoverable by a postirradiation biased anneal and can be prevented entirely if devices are cycled during irradiation. The authors have developed a model to simulate the observed degradation

Vancomycin Dosing in Obese Patients: Special Considerations and Novel Dosing Strategies.

Science.gov (United States)

Durand, Cheryl; Bylo, Mary; Howard, Brian; Belliveau, Paul

2018-06-01

To review the literature regarding vancomycin pharmacokinetics in obese patients and strategies used to improve dosing in this population. PubMed, EMBASE (1974 to November 2017), and Google Scholar searches were conducted using the search terms vancomycin, obese, obesity, pharmacokinetics, strategy, and dosing. Additional articles were selected from reference lists of selected studies. Included articles were those published in English with a primary focus on vancomycin pharmacokinetic parameters in obese patients and practical vancomycin dosing strategies, clinical experiences, or challenges of dosing vancomycin in this population. Volume of distribution and clearance are the pharmacokinetic parameters that most often affect vancomycin dosing in obese patients; both are increased in this population. Challenges with dosing in obese patients include inconsistent and inadequate dosing, observations that the obese population may not be homogeneous, and reports of an increased likelihood of supratherapeutic trough concentrations. Investigators have revised and developed dosing and monitoring protocols to address these challenges. These approaches improved target trough attainment to varying degrees. Some of the vancomycin dosing approaches provided promising results in obese patients, but there were notable differences in methods used to develop these approaches, and sample sizes were small. Although some approaches can be considered for validation in individual institutions, further research is warranted. This may include validating approaches in larger populations with narrower obesity severity ranges, investigating target attainment in indication-specific target ranges, and evaluating the impact of different dosing weights and methods of creatinine clearance calculation.

Receptor dose and patient dose in radiographic exposures: a 15 year review

International Nuclear Information System (INIS)

Peet, D.J.; Tyler, N.; Pryor, M.; Hollaway, P.; Strudley, C.; Leavesley, L.

2008-01-01

A patient dose programme has been established locally for the last 15 years across 109 hospitals and 250 X-ray rooms in line with the National Protocol, in conjunction with a programme to look at routine performance of these rooms. Routine performance checks initially looked primarily at film density and AEC performance but with the introduction of Computerised Radiography (CR) across UK hospitals and a revision of recommended procedures in the UK, the emphasis has shifted to assessing receptor dose under AEC control. Results show a wide variation in film density in the early years indicating sub optimal performance and dose. The spread was reduced over later years. The introduction of CR has led to a variety of approaches by the CR companies, X-ray companies and local sites. Receptor doses vary widely as a result. Large variations within hospitals were also observed. The doses over the last 15 years are reviewed and compared against diagnostic reference levels and with the performance of the imaging chain. Results show that patient dose programmes and optimisation strategies were having an impact, but the introduction of CR requires renewed efforts to ensure images and doses are optimised. (author)

Analysis of functional failure mode of commercial deep sub-micron SRAM induced by total dose irradiation

International Nuclear Information System (INIS)

Zheng Qi-Wen; Cui Jiang-Wei; Zhou Hang; Yu De-Zhao; Yu Xue-Feng; Lu Wu; Guo Qi; Ren Di-Yuan

2015-01-01

Functional failure mode of commercial deep sub-micron static random access memory (SRAM) induced by total dose irradiation is experimentally analyzed and verified by circuit simulation. We extensively characterize the functional failure mode of the device by testing its electrical parameters and function with test patterns covering different functional failure modes. Experimental results reveal that the functional failure mode of the device is a temporary function interruption caused by peripheral circuits being sensitive to the standby current rising. By including radiation-induced threshold shift and off-state leakage current in memory cell transistors, we simulate the influence of radiation on the functionality of the memory cell. Simulation results reveal that the memory cell is tolerant to irradiation due to its high stability, which agrees with our experimental result. (paper)

Cancer risk of low dose/low dose rate radiation: a meta-analysis of cancer data of mammals exposed to low doses of radiation

International Nuclear Information System (INIS)

Ogata, Hiromitsu; Magae, Junji

2008-01-01

Full text: Linear No Threshold (LNT) model is a basic theory for radioprotection, but the adaptability of this hypothesis to biological responses at low doses or at low dose rates is not sufficiently investigated. Simultaneous consideration of the cumulative dose and the dose rate is necessary for evaluating the risk of long-term exposure to ionizing radiation at low dose. This study intends to examine several numerical relationships between doses and dose rates in biological responses to gamma radiation. Collected datasets on the relationship between dose and the incidence of cancer in mammals exposed to low doses of radiation were analysed using meta-regression models and modified exponential (MOE) model, which we previously published, that predicts irradiation time-dependent biological response at low dose rate ionizing radiation. Minimum doses of observable risk and effective doses with a variety of dose rates were calculated using parameters estimated by fitting meta-regression models to the data and compared them with other statistical models that find values corresponding to 'threshold limits'. By fitting a weighted regression model (fixed-effects meta-regression model) to the data on risk of all cancers, it was found that the log relative risk [log(RR)] increased as the total exposure dose increased. The intersection of this regression line with the x-axis denotes the minimum dose of observable risk. These estimated minimum doses and effective doses increased with decrease of dose rate. The goodness of fits of MOE-model depended on cancer types, but the total cancer risk is reduced when dose rates are very low. The results suggest that dose response curve for cancer risk is remarkably affected by dose rate and that dose rate effect changes as a function of dose rate. For scientific discussion on the low dose exposure risk and its uncertainty, the term 'threshold' should be statistically defined, and dose rate effects should be included in the risk

Prediction of total dose effects on sub-micron process metal oxide semiconductor devices

International Nuclear Information System (INIS)

Kamimura, Hiroshi; Kato, Masataka.

1991-01-01

A method for correcting leakage currents is described to predict the radiation-induced threshold voltage shift of sub-micron MOSFETs. A practical model for predicting the leakage current generated by irradiation is also given on the basis of experimental results on 0.8-μm process MOSFETs. The constants in the threshold voltage shift model are determined from the 'true' I-V characteristic of the MOSFET, which is obtained by correction of leakage currents due to characteristic change of a parasitic transistor. In this way, the threshold voltage shift of the n-channel MOSFET irradiated at a low dose rate of 2 Gy(Si)/h was also calculated by using data from a high dose rate irradiation experiment (100 Gy(Si)/h, 5 h). The calculated result well represented the tendency of measured data on threshold voltage shift. The radiation-induced leakage current was considered to decay approximately in two exponential modes. The constants in this leakage current model were determined from the above high dose rate experiment. The response of leakage current predicted at a low dose rate of 2 Gy(Si)/h approximately agreed with that measured during and after irradiation. (author)

WE-A-18A-01: TG246 On Patient Dose From Diagnostic Radiation

Energy Technology Data Exchange (ETDEWEB)

Supanich, M [Rush University Medical Center, Chicago, IL (United States); Dong, F [The Cleveland Clinic, Solon, OH (United States); Andersson, J [Umea University, Umea (Sweden); Pavlicek, W [Mayo Clinic Arizona, Scottsdale, AZ (United States); Bolch, W [University Florida, Gainesville, FL (United States); Fetterly, K [Mayo Clinic, Rochester, MN (United States)

2014-06-15

Radiation dose from diagnostic and interventional radiations continues to be a focus of the regulatory, accreditation and standards organizations in the US and Europe. A Joint AAPM/EFOMP effort has been underway in the past year — having the goal to assist the clinical medical physicist with communicating optional and varied approaches in estimating (and validating) patient dose. In particular, the tools provided by DICOM Radiation Dose Structured Reports, either by themselves or as part of a networked data repository of dose related information are a rich source of actionable information. The tools of the medical physicist have evolved to include using DICOM data in meaningful ways to look at patient dose with respect to imaging practices. In addition to how accurate or reproducible a dose value is (totally necessary and our traditional workspace) it is now being asked how reproducible (patient to patient, device to device) are the delivered doses (new tasking)? Clinical medical physicists are best equipped to assist our radiology and technologist colleagues with this effort. The purpose of this session is to review the efforts of TG246 - bringing forward a summary content of the TG246 Report including specific dose descriptors for CT and Fluoroscopy — particularly in a focus of leveraging the RDSR as a means for monitoring good practices ALARA. Additionally, rapidly evolving technologies for more refined dose estimates are now in use. These will be presented as they look to having highly patient specific dose estimates in automated use.

Dose fractionation in synchrotron radiation x-ray phase micro-tomography

International Nuclear Information System (INIS)

Frachon, Thibaut; Weber, Loriane; Hesse, Bernhard; Rit, Simon; Dong, Pei; Olivier, Cecile; Peyrin, Françoise; Langer, Max

2015-01-01

Phase sensitive x-ray imaging expands the applicability of standard attenuation based techniques by offering several orders of magnitude of increase in sensitivity. Due to the short wavelength, x-ray phase is not directly measurable, but has to be put in evidence by the use of phase contrast techniques. The phase can then be reconstructed from one or several phase contrast images. In this study, we consider synchrotron x-ray phase micro-computed tomography (μCT) based on free space propagation for heterogeneous and strongly absorbing objects. This technique generally relies on acquiring several scans of the sample at different detector distances. It is also generally believed that multi-distance phase μCT needs a higher dose input than single distance phase μCT. The purpose of this work is to study the impact of different means of dose fractionation on the reconstructed image quality. We define different acquistion schemes in multi-distance in-line phase μCT. Previously, the exposure time at each sample-to-detector distance was usually kept the same. Here, we let not only the number of distances vary but also the fraction of exposure time at each distance, the total exposure time being kept constant. Phase retrieval is performed with the mixed approach algorithm. The reconstructed μCT images are compared in terms of accuracy, precision and resolution. In addition, we also compare the result of dose fractionated multi distance phase μCT to single distance phase μCT using the same total radiation dose. In the multi-distance approach, we find that using different exposure times on each distance improves the image quality in the reconstructed image. Further, we show that, despite having the same total dose delivery, the multi distance imaging method gives better image quality than the single distance method, at the cost of an additional overhead from camera displacements and reference images. We show that by optimizing the acquistion parameters in terms of

Serum level modifications of female sex hormones after radiocastration with different total doses

International Nuclear Information System (INIS)

Naujokat, B.; Rohloff, R.; Willich, N.; Eiermann, W.

1988-01-01

We determined serum level of estradiol, FSH and LH over a period of six to eight weeks after ovarian irradiation for castration with different doses (2x2.5 Gy/3x2.5 Gy/4x2.5 Gy) in 15 patients with metastatic breast cancer as compared to changes after ovarectomy in five patients. The time course of the changing estradiol-, FSH and LH-serum levels sigificantly depends on the ovarian dose. After radiological castration with a dose of 4x2.5 Gy = 10 Gy in four days the estrogen levels decrease within two to three weeks, and the FSH- and LH-levels increase after three to four weeks into the postmenopausal range. Therefore, the time course is not very different from changes after ovarectomy. (orig.) [de

Keeping an eye on the ring: COMS plaque loading optimization for improved dose conformity and homogeneity.

Science.gov (United States)

Gagne, Nolan L; Cutright, Daniel R; Rivard, Mark J

2012-09-01

To improve tumor dose conformity and homogeneity for COMS plaque brachytherapy by investigating the dosimetric effects of varying component source ring radionuclides and source strengths. The MCNP5 Monte Carlo (MC) radiation transport code was used to simulate plaque heterogeneity-corrected dose distributions for individually-activated source rings of 14, 16 and 18 mm diameter COMS plaques, populated with (103)Pd, (125)I and (131)Cs sources. Ellipsoidal tumors were contoured for each plaque size and MATLAB programming was developed to generate tumor dose distributions for all possible ring weighting and radionuclide permutations for a given plaque size and source strength resolution, assuming a 75 Gy apical prescription dose. These dose distributions were analyzed for conformity and homogeneity and compared to reference dose distributions from uniformly-loaded (125)I plaques. The most conformal and homogeneous dose distributions were reproduced within a reference eye environment to assess organ-at-risk (OAR) doses in the Pinnacle(3) treatment planning system (TPS). The gamma-index analysis method was used to quantitatively compare MC and TPS-generated dose distributions. Concentrating > 97% of the total source strength in a single or pair of central (103)Pd seeds produced the most conformal dose distributions, with tumor basal doses a factor of 2-3 higher and OAR doses a factor of 2-3 lower than those of corresponding uniformly-loaded (125)I plaques. Concentrating 82-86% of the total source strength in peripherally-loaded (131)Cs seeds produced the most homogeneous dose distributions, with tumor basal doses 17-25% lower and OAR doses typically 20% higher than those of corresponding uniformly-loaded (125)I plaques. Gamma-index analysis found > 99% agreement between MC and TPS dose distributions. A method was developed to select intra-plaque ring radionuclide compositions and source strengths to deliver more conformal and homogeneous tumor dose distributions than

A survey of chest medical X-ray doses

International Nuclear Information System (INIS)

Lomba, M.; Conha, P.G. da; Almeida, C.E. de

1996-01-01

The medical X-ray exposures due to radiological examinations are responsible for the largest contribution to the population collective dose as result of the normal use of artificial sources of radiation. The relative impact of the medical exposures to the total dose received by the population from all kinds of radiation sources varies from country to country and in some cases within the same country. The dose variations observed for a specific type of examination are in general associated to several factors i.e. the type of film-ecran combination, the choice of the appropriate physical parameters of the X-ray generator (Kvp, filament current, exposure time) and finally to the film processing conditions. At the present moment the data available in Brazil are scarce and scanty to allow a complete analyzis of this question so needed by the health authorities to justify the implementation of a quality assurance and dose reduction programs. In addition, it is desirable to establish a cost effective operation based on simple administrative concepts in order to reduce the number of films retake, then increasing the life expectancy of the equipment and the number of radiological procedures. The aim of this work was to assess the typical doses of an PA and LAT chest wall X-ray examinations in five different public hospitals (a University Hospital, a Cancer Hospital, a Navy Hospital, an Emergency Hospital and a State General Hospital), as representative of the city of Rio de Janeiro, and compare the results with the international data and recommendations available. (author)

Comments on 'Reconsidering the definition of a dose-volume histogram'-dose-mass histogram (DMH) versus dose-volume histogram (DVH) for predicting radiation-induced pneumonitis

International Nuclear Information System (INIS)

Mavroidis, Panayiotis; Plataniotis, Georgios A; Gorka, Magdalena Adamus; Lind, Bengt K

2006-01-01

In a recently published paper (Nioutsikou et al 2005 Phys. Med. Biol. 50 L17) the authors showed that the use of the dose-mass histogram (DMH) concept is a more accurate descriptor of the dose delivered to lung than the traditionally used dose-volume histogram (DVH) concept. Furthermore, they state that if a functional imaging modality could also be registered to the anatomical imaging modality providing a functional weighting across the organ (functional mass) then the more general and realistic concept of the dose-functioning mass histogram (D[F]MH) could be an even more appropriate descriptor. The comments of the present letter to the editor are in line with the basic arguments of that work since their general conclusions appear to be supported by the comparison of the DMH and DVH concepts using radiobiological measures. In this study, it is examined whether the dose-mass histogram (DMH) concept deviated significantly from the widely used dose-volume histogram (DVH) concept regarding the expected lung complications and if there are clinical indications supporting these results. The problem was investigated theoretically by applying two hypothetical dose distributions (Gaussian and semi-Gaussian shaped) on two lungs of uniform and varying densities. The influence of the deviation between DVHs and DMHs on the treatment outcome was estimated by using the relative seriality and LKB models using the Gagliardi et al (2000 Int. J. Radiat. Oncol. Biol. Phys. 46 373) and Seppenwoolde et al (2003 Int. J. Radiat. Oncol. Biol. Phys. 55 724) parameter sets for radiation pneumonitis, respectively. Furthermore, the biological equivalent of their difference was estimated by the biologically effective uniform dose (D-bar) and equivalent uniform dose (EUD) concepts, respectively. It is shown that the relation between the DVHs and DMHs varies depending on the underlying cell density distribution and the applied dose distribution. However, the range of their deviation in terms of

Measurement and comparison of skin dose using OneDose MOSFET and Mobile MOSFET for patients with acute lymphoblastic leukemia.

Science.gov (United States)

Mattar, Essam H; Hammad, Lina F; Al-Mohammed, Huda I

2011-07-01

Total body irradiation is a protocol used to treat acute lymphoblastic leukemia in patients prior to bone marrow transplant. It is involved in the treatment of the whole body using a large radiation field with extended source-skin distance. Therefore measuring and monitoring the skin dose during the treatment is important. Two kinds of metal oxide semiconductor field effect transistor (OneDose MOSFET and mobile MOSEFT) dosimeter are used during the treatment delivery to measure the skin dose to specific points and compare it with the target prescribed dose. The objective of this study was to compare the variation of skin dose in patients with acute lymphatic leukemia (ALL) treated with total body irradiation (TBI) using OneDose MOSFET detectors and Mobile MOSFET, and then compare both results with the target prescribed dose. The measurements involved 32 patient's (16 males, 16 females), aged between 14-30 years, with an average age of 22.41 years. One-Dose MOSFET and Mobile MOSFET dosimetry were performed at 10 different anatomical sites on every patient. The results showed there was no variation between skin dose measured with OneDose MOSFET and Mobile MOSFET in all patients. Furthermore, the results showed for every anatomical site selected there was no significant difference in the dose delivered using either OneDose MOSFET detector or Mobile MOSFET as compared to the prescribed dose. The study concludes that One-Dose MOSFET detectors and Mobile MOSFET both give a direct read-out immediately after the treatment; therefore both detectors are suitable options when measuring skin dose for total body irradiation treatment.

ELDRS Characterization for a Very High Dose Mission

Science.gov (United States)

Harris, Richard D.; McClure, Steven S.; Rax, Bernard G.; Kenna, Aaron J.; Thorbourn, Dennis O.; Clark, Karla B.; Yan, Tsun-Yee

2010-01-01

Evaluation of bipolar linear parts which may have Enhanced Low Dose Rate Sensitivity (ELDRS) is problematic for missions that have very high dose radiation requirements. The accepted standards for evaluating parts that display ELDRS require testing at a very low dose rate which could be prohibitively long for very high dose missions. In this work, a methodology for ELDRS characterization of bipolar parts for mission doses up to 1 Mrad(Si) is evaluated. The procedure employs an initial dose rate of 0.01 rad(Si)/s to a total dose of 50 krad(Si) and then changes to 0.04 rad(Si)/s to a total dose of 1 Mrad(Si). This procedure appears to work well. No change in rate of degradation with dose has been observed when the dose rate is changed from 0.01 to 0.04 rad(Si)/s. This is taken as an indication that the degradation due to the higher dose rate is equivalent to that at the lower dose rate at the higher dose levels, at least for the parts studied to date. In several cases, significant parameter degradation or functional failure not observed at HDR was observed at fairly high total doses (50 to 250 krad(Si)) at LDR. This behavior calls into question the use of dose rate trend data and enhancement factors to predict LDR performance.

Correlation of patient maximum skin doses in cardiac procedures with various dose indicators

International Nuclear Information System (INIS)

Domienik, J.; Papierz, S.; Jankowski, J.; Peruga, J.Z.; Werduch, A.; Religa, W.

2008-01-01

In most countries of European Union, legislation requires the determination of the total skin dose received by patients during interventional procedures in order to prevent deterministic damages. Various dose indicators like dose-area product (DAP), cumulative dose (CD) and entrance dose at the patient plane (EFD) are used for patient dosimetry purposes in clinical practice. This study aimed at relating those dose indicators with doses ascribed to the most irradiated areas of the patient skin usually expressed in terms of local maximal skin dose (MSD). The study was performed in two different facilities for two most common cardiac procedures coronary angiography (CA) and percutaneous coronary interventions (PCI). For CA procedures, the registered values of fluoroscopy time, total DAP and MSD were in the range (0.7-27.3) min, (16-317) Gy cm 2 and (43-1507) mGy, respectively, and for interventions, accordingly (2.1-43.6) min, (17-425) Gy cm 2 , (71-1555) mGy. Moreover, for CA procedures, CD and EFD were in the ranges (295-4689) mGy and (121-1768) mGy and for PCI (267-6524) mGy and (68-2279) mGy, respectively. No general and satisfactory correlation was found for safe estimation of MSD. However, results show that the best dose indicator which might serve for rough, preliminary estimation is DAP value. In the study, the appropriate trigger levels were proposed for both facilities. (authors)

Dose Escalation of Total Marrow Irradiation With Concurrent Chemotherapy in Patients With Advanced Acute Leukemia Undergoing Allogeneic Hematopoietic Cell Transplantation

Energy Technology Data Exchange (ETDEWEB)

Wong, Jeffrey Y.C., E-mail: jwong@coh.org [Department of Radiation Oncology, City of Hope National Medical Center, Duarte, California (United States); Forman, Stephen; Somlo, George [Department of Hematology/Hematopoietic Cell Transplantation, City of Hope National Medical Center, Duarte, California (United States); Rosenthal, Joseph [Department of Hematology/Hematopoietic Cell Transplantation, City of Hope National Medical Center, Duarte, California (United States); Department of Pediatrics, City of Hope National Medical Center, Duarte, California (United States); Liu An; Schultheiss, Timothy; Radany, Eric [Department of Radiation Oncology, City of Hope National Medical Center, Duarte, California (United States); Palmer, Joycelynne [Department of Biostatistics, City of Hope National Medical Center, Duarte, California (United States); Stein, Anthony [Department of Hematology/Hematopoietic Cell Transplantation, City of Hope National Medical Center, Duarte, California (United States)

2013-01-01

Purpose: We have demonstrated that toxicities are acceptable with total marrow irradiation (TMI) at 16 Gy without chemotherapy or TMI at 12 Gy and the reduced intensity regimen of fludarabine/melphalan in patients undergoing hematopoietic cell transplantation (HCT). This article reports results of a study of TMI combined with higher intensity chemotherapy regimens in 2 phase I trials in patients with advanced acute myelogenous leukemia or acute lymphoblastic leukemia (AML/ALL) who would do poorly on standard intent-to-cure HCT regimens. Methods and Materials: Trial 1 consisted of TMI on Days -10 to -6, etoposide (VP16) on Day -5 (60 mg/kg), and cyclophosphamide (CY) on Day -3 (100 mg/kg). TMI dose was 12 (n=3 patients), 13.5 (n=3 patients), and 15 (n=6 patients) Gy at 1.5 Gy twice daily. Trial 2 consisted of busulfan (BU) on Days -12 to -8 (800 {mu}M min), TMI on Days -8 to -4, and VP16 on Day -3 (30 mg/kg). TMI dose was 12 (n=18) and 13.5 (n=2) Gy at 1.5 Gy twice daily. Results: Trial 1 had 12 patients with a median age of 33 years. Six patients had induction failures (IF), and 6 had first relapses (1RL), 9 with leukemia blast involvement of bone marrow ranging from 10%-98%, 5 with circulating blasts (24%-85%), and 2 with chloromas. No dose-limiting toxicities were observed. Eleven patients achieved complete remission at Day 30. With a median follow-up of 14.75 months, 5 patients remained in complete remission from 13.5-37.7 months. Trial 2 had 20 patients with a median age of 41 years. Thirteen patients had IF, and 5 had 1RL, 2 in second relapse, 19 with marrow blasts (3%-100%) and 13 with peripheral blasts (6%-63%). Grade 4 dose-limiting toxicities were seen at 13.5 Gy (stomatitis and hepatotoxicity). Stomatitis was the most frequent toxicity in both trials. Conclusions: TMI dose escalation to 15 Gy is possible when combined with CY/VP16 and is associated with acceptable toxicities and encouraging outcomes. TMI dose escalation is not possible with BU/VP16 due to

Assessment of dose due to exposure to indoor radon and thoron progeny

Directory of Open Access Journals (Sweden)

Prasad Ganesh

2010-01-01

Full Text Available The components of the effective dose through inhalation from radon and its progeny are important for human health since they contribute to more than 50% of the total radiation dose from natural sources. As a consequence, radon has been identified as the second leading cause of lung cancer after smoking. Radon and its short lived decay products (218Po, 214Pb, 214Bi, 214Po present in dwellings are a radiation hazard, particularly if such sources are concentrated in the enclosed areas like poorly ventilated houses and underground mines. The indoor radon, thoron, and progeny concentrations were measured in a small hilly town of Budhakedar and the surrounding area of Tehri Garhwal, India, by using LR-115 Type II plastic track detector in a twin cup radon dosimeter. The concentrations of radon progeny were measured as the highest in winter and the lowest in summer while the thoron progeny concentration was found maximum in rainy season and minimum in autumn. The annual exposure to the potential alpha energy of radon and thoron were found to vary from 0.04 WLM to 0.69 WLM with an average value of 0.29 WLM, and 0.03 WLM to 0.37 WLM with an aver- age value of 0.16 WLM, respectively. The annual effective dose due to the exposure to indoor radon and progeny in Budhakedar homes was found to vary from 0.16 mSv to 2.72 mSv with an average value of 1.14 mSv and the effective dose due to the exposure to thoron and progeny was found to vary from 0.18 mSv to 2.49 mSv with an average value of 1.05 mSv. The results of systematic study have been obtained by considering the room as a space in which the radon and thoron levels are directly related to the dynamic and static parameters.

Commissioning of a MOSFET in-vivo patient dose verification system

International Nuclear Information System (INIS)

Jenetsky, G.O.; Brown, R.L.

2004-01-01

Gy. 5mm and 10mm out of the field MOSFETs and TLDs recorded the same dose. The paired t-test performed on the data taken from 11 separate lens measurements did not show any significant difference between the means at the 95% level of significance (left lens p=0.13, right lens 0.67). The negative y-intercept suggests that they should be added to the raw reading before being converted to dose, this is important when measuring in low dose regions. The problem with a larger than expected variation between energies, can easily be overcome by using individual calibration factors for each energy. For central beam and scatter doses results between TLDs and MOSFETs varied by 1cGy. The greatest variation of 6cGy occurred at beam edge where the dose gradient is greatest. This can be attributed to TLD chips measuring over a 9mm 2 area while a MOSFET measures over 0.04mm 2 . Multiple readings per patient are now being performed relying on slight positional changes to provide a larger area for the MOSFETs to record 'point' measurements. After a careful commissioning procedure, the MOSFET 20 dose verification system provides reliable, consistent and accurate measurements equal to that of a TLD system. However, the MOSFETs can be prepared for use within seconds, and give results of total dose within minutes, and can be re-used instantaneously making them a far more efficient method of patient dose verification. Copyright (2004) Australasian College of Physical Scientists and Engineers in Medicine

High dose potassium-nitrate chemical dosimeter

International Nuclear Information System (INIS)

Dorda de Cancio, E.M.; Munoz, S.S.

1982-01-01

This dosimeter is used to control 10 kGY-order doses (1 Mrad). Nitrate suffers a radiolitic reduction phenomena, which is related to the given dose. The method to use potassium nitrate as dosimeter is described, as well as effects of the temperature of irradiation, pH, nitrate concentration and post-irradiation stability. Nitrate powder was irradiated at a Semi-Industrial Plant, at Centro Atomico Ezeiza, and also in a Gammacell-220 irradiator. The dose rates used were 2,60 and 1,80 KGY/hour, and the given doses varied between 1,0 and 150 KGY. The uncertainty was +-3% in all the range. (author) [es

Dosimetric verification of helical tomotherapy for total scalp irradiation

International Nuclear Information System (INIS)

Hardcastle, Nicholas; Soisson, Emilie; Metcalfe, Peter; Rosenfeld, Anatoly B.; Tome, Wolfgang A.

2008-01-01

Total scalp irradiation is a treatment technique used for a variety of superficial malignancies. Helical tomotherapy is an effective technique used for total scalp irradiation. Recent published work has shown the TomoTherapy planning system to overestimate the superficial dose. In this study, the superficial doses for a helical tomotherapy total scalp irradiation have been measured on an anthropomorphic phantom using radiochromic and radiographic film as well as a new skin dosimeter, the MOSkin. The superficial dose was found to be accurately calculated by the TomoTherapy planning system. This is in contrast to recent reports, probably due to a combination of the smaller dose grid resolution used in planning and this particular treatment primarily consisting of beamlets tangential to the scalp. The superficial dose was found to increase from 33.6 to 41.2 Gy and 36.0 to 42.0 Gy over the first 2 mm depth in the phantom in selected regions of the PTV, measured with radiochromic film. The prescription dose was 40 Gy. The superficial dose was at the prescription dose or higher in some regions due to the bolus effect of the thermoplastic head mask and the head rest used to aid treatment setup. It is suggested that to achieve the prescription dose at the surface (≤2 mm depth) bolus or a custom thermoplastic helmet is used.

Studying and measuring the gamma radiation doses in Homs city

International Nuclear Information System (INIS)

Sofaan, A. H.

2001-01-01

The gamma radiation dose was measured in Homs city by using many portable dosimeters (electronic dosimeter and Geiger-Muller). The measurements were carried out in the indoor and outdoor buildings, for different time period, through one year (1999-2000). High purity germanium detector with low back ground radiation (HpGe) was used to determine radiation element contained in some building and the surrounding soil. The statistical analysis laws were applied to make sure that the measured dose distribution around average value is normal distribution. The measurement indicates that the gamma indoor dose varies from 312μSv/y to 511μSv/y, with the average annual dose of 385μSv/y. However the gamma outdoor dose rate varies from 307μSv/y to 366μSv/y with an average annual dose 385μSv/y. The annual outdoor gamma radiation dose is about %16 lower than the outdoor dose in Homs City. These measurements have indicated that environmental gamma doses in Homs City are relatively low. This is because that most of the soils and rocks in the area are limestone. (author)

SU-E-T-501: Normal Tissue Toxicities of Pulsed Low Dose Rate Radiotherapy and Conventional Radiotherapy: An in Vivo Total Body Irradiation Study

Energy Technology Data Exchange (ETDEWEB)

Cvetkovic, D; Zhang, P; Wang, B; Chen, L; Ma, C [Fox Chase Cancer Center, Philadelphia, PA (United States)

2014-06-01

Purpose: Pulsed low dose rate radiotherapy (PLDR) is a re-irradiation technique for therapy of recurrent cancers. We have previously shown a significant difference in the weight and survival time between the mice treated with conventional radiotherapy (CRT) and PLDR using total body irradiation (TBI). The purpose of this study was to investigate the in vivo effects of PLDR on normal mouse tissues.Materials and Methods: Twenty two male BALB/c nude mice, 4 months of age, were randomly assigned into a PLDR group (n=10), a CRT group (n=10), and a non-irradiated control group (n=2). The Siemens Artiste accelerator with 6 MV photon beams was used. The mice received a total of 18Gy in 3 fractions with a 20day interval. The CRT group received the 6Gy dose continuously at a dose rate of 300 MU/min. The PLDR group was irradiated with 0.2Gyx20 pulses with a 3min interval between the pulses. The mice were weighed thrice weekly and sacrificed 2 weeks after the last treatment. Brain, heart, lung, liver, spleen, gastrointestinal, urinary and reproductive organs, and sternal bone marrow were removed, formalin-fixed, paraffin-embedded and stained with H and E. Morphological changes were observed under a microscope. Results: Histopathological examination revealed atrophy in several irradiated organs. The degree of atrophy was mild to moderate in the PLDR group, but severe in the CRT group. The most pronounced morphological abnormalities were in the immune and hematopoietic systems, namely spleen and bone marrow. Brain hemorrhage was seen in the CRT group, but not in the PLDR group. Conclusions: Our results showed that PLDR induced less toxicity in the normal mouse tissues than conventional radiotherapy for the same dose and regimen. Considering that PLDR produces equivalent tumor control as conventional radiotherapy, it would be a good modality for treatment of recurrent cancers.

Disposition in male volunteers of a subanaesthetic intravenous dose of an oil in water emulsion of 14C-propofol.

Science.gov (United States)

Simons, P J; Cockshott, I D; Douglas, E J; Gordon, E A; Hopkins, K; Rowland, M

1988-04-01

1. An intravenous dose of 14C-propofol (0.47 mg/kg) administered to six male volunteers was rapidly eliminated with 88% recovered in the urine in 5 days and less than 2% in faeces. 2. The dose was cleared by metabolism with less than 0.3% excreted unchanged. The major metabolites were the glucuronic acid conjugate of propofol and the glucuronic acid and sulphate conjugates of its hydroxylated derivative, 2,6-diisopropyl-1,4-quinol. Propofol glucuronide accounted for about 53% of the urinary radioactivity and was the major metabolite in plasma from 30 min post dose. 3. The blood concentration of propofol declined in a biphasic manner from a maximum mean value of 0.44 microgram/ml, 2 min after injection. The half-lives of the first and second exponential phases, mean values 5 min and 97 min respectively, varied widely among subjects. A proportion of the dose was cleared slowly, probably due to slow release from less well perfused tissues. Propofol accounted for 94% of the total blood radioactivity at 2 min but only about 6% from 3 to 8 h post dose. 4. Propofol has a volume of distribution equivalent to about 3 to 4 times body weight, and a mean total body clearance of 2.2 1/min.

A graphical review of radiogenic animal cancer data using the 'dose and dose-rate map'

International Nuclear Information System (INIS)

Yoshida, Kazuo; Hoshi, Yuko; Sakai, Kazuo

2008-01-01

We have been investigating the effects of low dose or low dose rate irradiation on mice, using our low dose-rate irradiation facilities. In these studies, we found that the effects were highly dependent on both total dose and dose rate. To show this visually, we proposed the 'dose/dose rate map', and plotted the results of our laboratory and our co-workers. The map demonstrated that dose/dose rate plane could be divided into three areas; 1) An area where harmful effects are observed, 2) An area where no harmful effects are observed, and 3) Another area, between previous two areas, where certain protective functions are enhanced. As this map would be a powerful tool to find some trend among the vast numbers of data relating the biological effects of ionizing radiation, we have developed a computer program which plots the collected data on the dose/dose rate map sorting by experimental conditions. In this study, we graphically reviewed and analyzed the data relating to the lifespan studies of animals with a view to determining the relationships between doses and dose rates of ionizing radiation and cancer incidence. The data contains about 800 sets of experiments, which concerns 187,000 animals exposed to gamma ray or X-ray and their 112,000 controls, and total of about 30,000 cancers in exposed animals and 14,000 cancers in controls. About 800 points of data were plotted on the dose/dose rate map. The plot showed that 1) The divided three areas in the dose/dose rate map were generally confirmed by these 800 points of data, and 2) In some particular conditions, e.g. sarcoma by X-rays, the biologically effective area is extended to relatively high dose/dose rate area. (author)

Relationship between Individual External Doses, Ambient Dose Rates and Individuals' Activity-Patterns in Affected Areas in Fukushima following the Fukushima Daiichi Nuclear Power Plant Accident.

Directory of Open Access Journals (Sweden)

Wataru Naito

Full Text Available The accident at Fukushima Daiichi Nuclear Power Plant on March 11, 2011, released radioactive material into the atmosphere and contaminated the land in Fukushima and several neighboring prefectures. Five years after the nuclear disaster, the radiation levels have greatly decreased due to physical decay, weathering, and decontamination operations in Fukushima. The populations of 12 communities were forced to evacuate after the accident; as of March 2016, the evacuation order has been lifted in only a limited area, and permanent habitation is still prohibited in most of the areas. In order for the government to lift the evacuation order and for individuals to return to their original residential areas, it is important to assess current and future realistic individual external doses. Here, we used personal dosimeters along with the Global Positioning System and Geographic Information System to understand realistic individual external doses and to relate individual external doses, ambient doses, and activity-patterns of individuals in the affected areas in Fukushima. The results showed that the additional individual external doses were well correlated to the additional ambient doses based on the airborne monitoring survey. The results of linear regression analysis suggested that the additional individual external doses were on average about one-fifth that of the additional ambient doses. The reduction factors, which are defined as the ratios of the additional individual external doses to the additional ambient doses, were calculated to be on average 0.14 and 0.32 for time spent at home and outdoors, respectively. Analysis of the contribution of various activity patterns to the total individual external dose demonstrated good agreement with the average fraction of time spent daily in each activity, but the contribution due to being outdoors varied widely. These results are a valuable contribution to understanding realistic individual external doses

Patient doses in interventional cardiology procedures

International Nuclear Information System (INIS)

Domienik, J.; Papierz, S.; Jankowski, J.; Peruga, J.Z.

2008-01-01

In most countries of European Union legislation requires the determination of the total skin dose to patient resulting from interventional procedures to assess the risk of deterministic effect. To this end, various dose indicators like dose area product (DAP), cumulative dose (CD) and entrance dose at the patient plane (EFD) are used in clinical practice. The study aims at relating those dose indicators with doses ascribe to the most irradiated areas of the patient skin usually expressed in terms of local maximal skin dose (MSD). For the study the local MSD and related to their areas are investigated and compared for coronary angiography CA and intervention (PCI). Two methods implying radiographic films Kodak EDR2 and matrixes of thermoluminescent dosimeters (TLDs) are applied for direct measurements of dose distribution for selected procedures. Both methods are compared. Additionally, for patient dosimetry the following data: MSD, CD, EFD, fluoroscopy time (FT), number of acquired images, total DAP, fluoro-DAP and record-DAP were collected for randomly selected procedure. The statistical quantities like: median, 3 rd quartile, mean and standard deviation for all dosimetric parameters are determined. Preliminary study showed that the values of data collected for coronary procedures are in the ranges 0,7 - 27,3 min for fluoroscopy time, 50 - 350 Gy cm 2 for total DAP, 300 - 2000 mGy for CD, 140 - 2000 mGy for EFD and 100 - 1500 mGy for local maximal skin dose. For interventions the ranges are, accordingly 3,0 - 43,6 min , 25 - 450 Gy cm 2 , 270 - 6600 mGy, 80 - 2600 mGy and 80 - 1500 mGy. As a result of the study the correlations between dose indicators and local MSD are analyzed. The concentration of dose on irradiated films are going to be investigated in some detail as well. (author)

Estimation of population doses from diagnostic medical examinations in Japan, 1974. III. Per caput mean marrow dose and leukemia significant dose

Energy Technology Data Exchange (ETDEWEB)

Hashizume, T; Maruyama, T; Kumamoto, Y [National Inst. of Radiological Sciences, Chiba (Japan)

1976-03-01

The mean per capita marrow dose and leukemia-significant dose from radiographic and fluoroscopic examinations in Japan have been estimated based on a 1974 nation wide survey of randomly sampled hospitals and clinics. To determine the mean marrow dose to an individual from a certain exposure of a given type of examination, the active marrow in the whole body was divided into 119 parts for an adult and 103 for a child. Dosimetric points on which the individual marrow doses were determined were set up in the center of each marrow part. The individual marrow doses at the dosimetric points in the beams of practical diagnostic x-rays were calculated on the basis of the exposure data on the patients selected in the nation wide survey, using depth dose curves experimentally determined for diagnostic x-rays. The mean individual marrow dose was averaged over the active marrow by summing, for each dosimetric point, the product of the fraction of active marrow exposed and the individual marrow dose at the dosimetric point. The leukemia significant dose was calculated by adopting a weighting factor that is, a leukemia significant factor. The factor was determined from the shape of the time-incidence curve for radiation-induced leukemia from the Hiroshima A-bomb and from the survival statistics for the average population. The resultant mean per capita marrow dose from radiographic and fluoroscopic examination was 37.0 and 70.0 mrad/person/year, respectively, with a total of 107.05 mrad/person/year. The leukemia significant dose was 32.1 mrad/person/year for radiographic examination and 61.2 mrad/person/year, with a total of 93.3. These values were compared with those of 1960 and 1969.

A study on seasonal variations of indoor gamma dose in Bangladesh

International Nuclear Information System (INIS)

Miah, M. Idrish

2005-01-01

Monthly variation of gamma dose rate measured in indoor air of buildings of Bangladesh was found to vary cosinusoidally through a period of 1 year. Significant seasonal variations were observed. Maximum dose rate, however, was observed in January and a minimum in July. Dose rate in January was 32% higher than the annual average, whereas dose rate in July was 50% lower. Seasonally varied ventilation and air exchange rates of the houses might play an important role in the observed variation. The average reduction with respect to winter dose was 59% in summer. Because of lower ventilation and air exchange rates between indoor and outdoor atmosphere, it is expected that the indoor dose rate would be higher in basements than that of upper floors. Monthly dose rate was also found to be influenced by the meteorological conditions. Correlations between dose rate and temperature (r 2 =0.85), rainfall (r=-0.83) and atmospheric pressure (r=0.92) were obtained, but no significant correlation (r=-0.45) was seen between dose rate and humidity. The results show that the seasonal variations of indoor dose rates should be taken into account to estimate annual effective dose equivalent. (author)

Experimental infection of cliff swallows (Petrochelidon pyrrhonota) with varying doses of West Nile virus

Science.gov (United States)

Oesterle, P.T.; Nemeth, N.M.; VanDalen, Kaci K.; Sullivan, H.; Bentler, K.T.; Young, G.R.; McLean, R.G.; Clark, L.; Smeraski, C.; Hall, Jeffrey S.

2009-01-01

Cliff swallows (Petrochelidon pyrrhonota) were inoculated with differing doses of West Nile virus (WNV) to evaluate their potential role as reservoir hosts in nature. Swallows often nest in large colonies in habitats and months associated with high mosquito abundance and early WNV transmission in North America. Additionally, cliff swallow diet consists of insects, including mosquitoes, leading to an additional potential route of WNV infection. The average peak viremia titer among infected cliff swallows was 106.3 plaque-forming units (PFU)/mL serum and the reservoir competence index was 0.34. There was no correlation between dose and probability of becoming infected or viremia peak and duration. Oral shedding was detected from 2 to 14 days post-inoculation with an average peak titer of 1044 PFU/swab. These results suggest that cliff swallows are competent reservoir hosts of WNV and therefore, they may play a role in early seasonal amplification and maintenance of WNV. Copyright ?? 2009 by The American Society of Tropical Medicine and Hygiene.

A 0.18 micrometer CMOS Thermopile Readout ASIC Immune to 50 MRAD Total Ionizing Dose (SI) and Single Event Latchup to 174MeV-cm(exp 2)/mg

Science.gov (United States)

Quilligan, Gerard T.; Aslam, Shahid; Lakew, Brook; DuMonthier, Jeffery J.; Katz, Richard B.; Kleyner, Igor

2014-01-01

Radiation hardened by design (RHBD) techniques allow commercial CMOS circuits to operate in high total ionizing dose and particle fluence environments. Our radiation hard multi-channel digitizer (MCD) ASIC (Figure 1) is a versatile analog system on a chip (SoC) fabricated in 180nm CMOS. It provides 18 chopper stabilized amplifier channels, a 16- bit sigma-delta analog-digital converter (SDADC) and an on-chip controller. The MCD was evaluated at Goddard Space Flight Center and Texas A&M University's radiation effects facilities and found to be immune to single event latchup (SEL) and total ionizing dose (TID) at 174 MeV-cm(exp 2)/mg and 50 Mrad (Si) respectively.

Dose measurements in the treatment of mycosis fungoides with total skin irradiation using a 4 MeV electron beam

Energy Technology Data Exchange (ETDEWEB)

Poli, M.E.R. [Hospital Real e Benemerita Sociedade Portuguesa de Beneficencia (Brazil); Todo, A.S.; Campos, L.L. [Instituto de Pesquisas Energeticas e Nucleares, CNEN/SP Travessa R, Sao Paulo (Brazil)

2000-05-01

The total skin irradiation (TSI) is one of the most efficient techniques in the treatment administered with curative intent of the mycosis fungoides. The cure may be obtained in 10% to 40% of cases. The original Stanford University technique, created in 1960, was applied in a 4.8 MeV linear accelerator, that provided 2.5 MeV electrons in the patient, by the use of 4 couple beams with the patient placed in front of the beam, 3 meters distant from the apparatus. In this work we describe a 4 MeV electrons beam treatment method. We intend to improve the uniformity of the dose in the patient, as well, to reduce the problems with the overlapping treatment fields, that occurs in conventional treatment that uses 1 meter of focus-skin distance, and the treatment time to the patient. Only one modification was done in the apparatus: the dose rate for this treatment was doubled. The patient is placed on a rotative base and he assumes successively 6 positions: stand up and perpendicular to the beam, distant 2.83 meters from the gantry, with 60 degrees of interval between the rotations. In each position, the patient receives a couple of beams (the beam angulation is 19.5 degrees above the transversal axis in the middle of the patient and 19.5 degrees below it). The dosimetric data obtained were compared to the international protocols (AAPM). The delivered doses in the patient were measured with thermoluminescent dosimeters placed on skin surface and with Kodak XV-2 films placed between different slabs of an anthropomorphic phantom. The dose distribution in the phantom shows a good uniformity, in all thickness of interest, so it is possible to use this technique in the treatment of the mycosis fungoides as well Kaposi's sarcoma. (author)

Operator dependency of the radiation exposure in cardiac interventions: feasibility of ultra low dose levels

International Nuclear Information System (INIS)

Emre Ozpelit, Mehmet; Ercan, Ertugrul; Pekel, Nihat; Tengiz, Istemihan; Yilmaz, Akar; Ozpelit, Ebru; Ozyurtlu, Ferhat

2017-01-01

Introduction: Mean radiation exposure in invasive cardiology varies greatly between different centres and interventionists. The International Commission on Radiological Protection and the EURATOM Council stipulate that, despite reference values, 'All medical exposure for radiodiagnostic purposes shall be kept as low as reasonably achievable' (ALARA). The purpose of this study is to establish the effects of the routine application of ALARA principles and to determine operator and procedure impact on radiation exposure in interventional cardiology. Materials and methods: A total of 240 consecutive cardiac interventional procedures were analysed. Five operators performed the procedures, two of whom were working in accordance with ALARA principles (Group 1 operators) with the remaining three working in a standard manner (Group 2 operators). Radiation exposure levels of these two groups were compared. Results: Total fluoroscopy time and the number of radiographic runs were similar between groups. However, dose area product and cumulative dose were significantly lower in Group 1 when compared with Group 2. Radiation levels of Group 1 were far below even the reference levels in the literature, thus representing an ultra-low-dose radiation exposure in interventional cardiology. Conclusion: By use of simple radiation reducing techniques, ultra-low-dose radiation exposure is feasible in interventional cardiology. Achievability of such levels depends greatly on operator awareness, desire, knowledge and experience of radiation protection. (authors)

[Single intravenous tranexamic acid dose to reduce blood loss in primary total knee replacement].

Science.gov (United States)

Sanz-Reig, J; Parra Ruiz, B; Ferrández Martínez, J; Martínez López, J F

2016-01-01

To evaluate the effectiveness and safety of a single intravenous dose of tranexamic acid in order to reduce blood loss in total knee replacement. Prospective observational study of the administration of tranexamic acid in patients undergoing primary total knee arthroplasty from November 2013 to February 2015, in which an autologous blood recovery system was used. The study included 98 patients, distributed into two groups of 49 patients according to whether or not they received intravenous tranexamic acid. The primary endpoint was the number of patients requiring autologous transfusion from the recovery system autologous blood recovery system. No drop-outs were recorded during follow-up. There were no significant differences between groups as regards the preoperative and hospital variables. The mean preoperative haemoglobin and haematocrit at 24 and 48 hours postoperatively were similar in both groups. The average volume of bleeding in the autologous blood recovery system and estimated average blood loss was lower in patients who had been administered tranexamic acid, with significant differences. No patients in the group that was administered tranexamic acid required blood autotransfusion. The transfusion rate was zero in the two groups. No adverse events related to the administration of tranexamic acid were recorded. Intravenous administration of tranexamic acid, according to the described protocol, has presented a non-autotransfusion or allo-transfusion rate of 100%, with no increased incidence of thrombotic events. Thus, its use in this group of patients is recommended. The indication should be individualized, its use justified in the patient medical records, and informed consent is mandatory. Copyright © 2015 SECOT. Published by Elsevier Espana. All rights reserved.

Estimation dose in organs of hyperthyroidism patients treated with I-131

International Nuclear Information System (INIS)

Farias de Lima, F.; Khoury, H.C.; Bertelli Neto, L.; Hazin, C.

1997-01-01

Full text: The absorbed dose in organs of hyperthyroidism patients, which received 370 MBq and 555 MBq of I-131 were estimated, using the MIRDOSE computational program and data of the ICRP-53 publication. The calculus were done considering an equal uptake to 45% and an effective half life of 5 days, these values are closed to the average values found in 17 studied patients. The thyroidal masses were previously determined by the physicians and varied between 40 g and 80 g The results showed that the dose in the thyroid, for an activity of 370 MBq, varied between 99 Gy and 49,5 Gy for the masses of 40 g and 80 g respectively. In the case of the administration of 555 MBq the patients had thyroidal masses between 60 g and 80 g and the doses varied between 99 Gy and 74,2 Gy, respectively. These values showed that the absorbed doses in thyroid are within limits expected for the hyperthyroidism therapy, which are of 506 Gy to 100 Gy. The 100 Gy dose would be exceeded, if the patients with thyroidal mass of 40 g had received a therapeutic dose of 555 MBq. The estimated media doses in others organs were relatively low, with inferior values of 0,1 Gy in kidneys, bone marrow and ovaries and of 0,19 Gy in stomach

Radiation dose reduction without compromise to image quality by alterations of filtration and focal spot size in cerebral angiography

Energy Technology Data Exchange (ETDEWEB)

Kim, Dong Joon; Park, Min Keun; Jung, Da Eun; Kang, Jung Han; Kim, Byung Moon [Dept. of Radiology, Yonsei University College of Medicine, Seoul (Korea, Republic of)

2017-08-01

Different angiographic protocols may influence the radiation dose and image quality. In this study, we aimed to investigate the effects of filtration and focal spot size on radiation dose and image quality for diagnostic cerebral angiography using an in-vitro model and in-vivo patient groups. Radiation dose and image quality were analyzed by varying the filtration and focal spot size on digital subtraction angiography exposure protocols (1, inherent filtration + large focus; 2, inherent + small; 3, copper + large; 4, copper + small). For the in-vitro analysis, a phantom was used for comparison of radiation dose. For the in-vivo analysis, bilateral paired injections, and patient cohort groups were compared for radiation dose and image quality. Image quality analysis was performed in terms of contrast, sharpness, noise, and overall quality. In the in-vitro analysis, the mean air kerma (AK) and dose area product (DAP)/frame were significantly lower with added copper filtration (protocols 3 and 4). In the in-vivo bilateral paired injections, AK and DAP/frame were significantly lower with filtration, without significant difference in image quality. The patient cohort groups with added filtration (protocols 3 and 4) showed significant reduction of total AK and DAP/patient without compromise to the image quality. Variations in focal spot size showed no significant differences in radiation dose and image quality. Addition of filtration for angiographic exposure studies can result in significant total radiation dose reduction without loss of image quality. Focal spot size does not influence radiation dose and image quality. The routine angiographic protocol should be judiciously investigated and implemented.

Dosimetric Effects of Air Pockets Around High-Dose Rate Brachytherapy Vaginal Cylinders

International Nuclear Information System (INIS)

Richardson, Susan; Palaniswaamy, Geethpriya; Grigsby, Perry W.

2010-01-01

Purpose: Most physicians use a single-channel vaginal cylinder for postoperative endometrial cancer brachytherapy. Recent published data have identified air pockets between the vaginal cylinders and the vaginal mucosa. The purpose of this research was to evaluate the incidence, size, and dosimetric effects of these air pockets. Methods and Materials: 25 patients receiving postoperative vaginal cuff brachytherapy with a high-dose rate vaginal cylinders were enrolled in this prospective data collection study. Patients were treated with 6 fractions of 200 to 400 cGy per fraction prescribed at 5 mm depth. Computed tomography simulation for brachytherapy treatment planning was performed for each fraction. The quantity, volume, and dosimetric impact of the air pockets surrounding the cylinder were quantified. Results: In 25 patients, a total of 90 air pockets were present in 150 procedures (60%). Five patients had no air pockets present during any of their treatments. The average number of air pockets per patient was 3.6, with the average total air pocket volume being 0.34 cm 3 (range, 0.01-1.32 cm 3 ). The average dose reduction to the vaginal mucosa at the air pocket was 27% (range, 9-58%). Ten patients had no air pockets on their first fraction but air pockets occurred in subsequent fractions. Conclusion: Air pockets between high-dose rate vaginal cylinder applicators and the vaginal mucosa are present in the majority of fractions of therapy, and their presence varies from patient to patient and fraction to fraction. The existence of air pockets results in reduced radiation dose to the vaginal mucosa.

The Relative Effects of Manual Versus Automatic Exposure Control on Radiation Dose to Vital Organs in Total Hip Arthroplasty.

Science.gov (United States)

Harper, Katharine D; Li, Shidong; Jennings, Rachel; Amer, Kamil M; Haydel, Christopher; Ali, Sayed

2018-01-01

of a total hip arthroplasty implant, exposure values increased threefold at some anatomic locations and surpassed 1 mSv, the generally accepted threshold for concern. Radiation exposure to radiosensitive organs increased up to threefold after total hip implantation with automatic exposure control and up to approximately 1.5 times with the manual protocol. Doses were greater with manual exposures than with automatic exposure control (except at the control probe on the stomach, where exposure was negligible, as expected). However, after implant placement, doses increased more with automatic exposure control than with manual exposure. This difference can be attributed to increased scatter and the difficulty of dose modification because of the density of the implant. Current radiographic protocols should be reassessed to determine if the benefits of frequent radiographs outweigh the newly demonstrated risks.

SPE dose prediction using locally weighted regression

International Nuclear Information System (INIS)

Hines, J. W.; Townsend, L. W.; Nichols, T. F.

2005-01-01

When astronauts are outside earth's protective magnetosphere, they are subject to large radiation doses resulting from solar particle events (SPEs). The total dose received from a major SPE in deep space could cause severe radiation poisoning. The dose is usually received over a 20-40 h time interval but the event's effects may be mitigated with an early warning system. This paper presents a method to predict the total dose early in the event. It uses a locally weighted regression model, which is easier to train and provides predictions as accurate as neural network models previously used. (authors)

SPE dose prediction using locally weighted regression

International Nuclear Information System (INIS)

Hines, J. W.; Townsend, L. W.; Nichols, T. F.

2005-01-01

When astronauts are outside Earth's protective magnetosphere, they are subject to large radiation doses resulting from solar particle events. The total dose received from a major solar particle event in deep space could cause severe radiation poisoning. The dose is usually received over a 20-40 h time interval but the event's effects may be reduced with an early warning system. This paper presents a method to predict the total dose early in the event. It uses a locally weighted regression model, which is easier to train, and provides predictions as accurate as the neural network models that were used previously. (authors)

Dose from drinking water Finland

International Nuclear Information System (INIS)

Maekelaeinen, Ilona; Salonen, Laina; Huikuri, Pia; Arvela, Hannu

1999-01-01

The dose from drinking water originates almost totally from naturally occurring radionuclides in the uranium-238 series, the most important nuclide being radon-222. Second comes lead-210, and third polonium-210. The mean age-group-weighted dose received by ingestion of drinking water is 0.14 mSv per year. More than half of the total cumulative dose of 750 manSv is received by the users of private wells, forming 13% of the population. The most exposed group comprises the users of wells drilled in bedrock, who receive 320 manSv while comprising only 4% of the population. The calculated number of annual cancer incidences due to drinking water is very sensitive to the dose-conversion factors of ingested radon used, as well as to the estimated lung cancer incidences caused by radon released from water into indoor air. (au)

Dose evaluation in special fluoroscopy procedures: Hysterosalpingography and Dacryocystography; Avaliacao de dose em procedimentos especiais de fluoroscopia: histerossalpingografia e dacriocistografia

Energy Technology Data Exchange (ETDEWEB)

Lopes, Cintya Carolina Barbosa

2006-04-15

The hysterosalpingography (HSG) and dacryocystography (DCG) are among the special fluoroscopy procedures. The HSG is a radiodiagnostic technique used to detect uterine and tubal pathologies and it is fundamental for the investigation of infertility. The DCG is a form of lacrimal system imaging, being important to show the level of obstruction, the presence of dilatation of the lacrimal sac, as well as alterations in nearby structures. At this research, the study of skin entrance dose was evaluated for these two special fluoroscopy procedures, besides the analyses of staff doses whose performs the exams. The exams of 22 HSG patients and 8 DCG patients were evaluated using TL-100 dosimeters attached on patient' skin at anatomical landmarks evolved on each exam. In the case of HSG, the results showed that skin entrance doses varied from 0.5 mGy to 73.4 mGy, with an average value of 22.1 mGy. The estimated uterus dose was 5.5 mGy, and 6.6 mGy was the average dose estimated to the ovaries. The patient' skin entrance dose undergoing to DCG examinations varied from 2.1 mGy to 10.6 mGy, and the average eye's dose was 6.1 mGy. The results of staff dose showed that, on HSG, the average dose on doctor's right hand was 4.3 mGy per examination. This value had to the fact that the physician introduces the contrast manually while all contrast exposures. In relation of DCG, the staff's dose values were nearby background radiation, evidencing that, inside of permitted limits, there is no risk for the physicians at this procedure. (author)

Bremsstrahlung doses from natural uranium ingots

International Nuclear Information System (INIS)

Anderson, J. L.; Hertel, N. E.

2005-01-01

In the past, some privately owned commercial facilities in the United States were involved in producing or processing radioactive materials used in the production of atomic weapons. Seven different geometrical objects, representative of the configurations of natural uranium metal potentially encountered by workers at these facilities, are modelled to determine gamma ray and Bremsstrahlung dose rates. The dose rates are calculated using the MCNP5 code and also by using the MICROSHIELD point-kernel code. Both gamma ray and Bremsstrahlung dose rates are calculated and combined to obtain a total dose rate. The two methods were found to be in good agreement despite differences in modelling assumptions and method differences. Computed total dose rates on the surface of these objects ranged from ∼51-84 μSv h -1 and 17-95 μSv h -1 using the MCNP5 and the MICROSHIELD modeling, respectively. The partitioning of the computed dose rates between gamma rays and Bremsstrahlung were the same order of magnitude for each object. (authors)

Bremsstrahlung doses from natural uranium ingots.

Science.gov (United States)

Anderson, Jeri L; Hertel, Nolan E

2005-01-01

In the past, some privately owned commercial facilities in the United States were involved in producing or processing radioactive materials used in the production of atomic weapons. Seven different geometrical objects, representative of the configurations of natural uranium metal potentially encountered by workers at these facilities, are modelled to determine gamma ray and bremsstrahlung dose rates. The dose rates are calculated using the MCNP5 code and also by using the MICROSHIELD point-kernel code. Both gamma ray and bremsstrahlung dose rates are calculated and combined to obtain a total dose rate. The two methods were found to be in good agreement despite differences in modelling assumptions and method differences. Computed total dose rates on the surface of these objects ranged from approximately 51-84 microSv h(-1) and 17-95 microSv h(-1) using the MCNP5 and the MICROSHIELD modeling, respectively. The partitioning of the computed dose rates between gamma rays and bremsstrahlung were the same order of magnitude for each object.

Determination of internal radiation dose due to intake of polonium 210 and lead 210 via smoking

International Nuclear Information System (INIS)

Al-Masri, M. S.; Kharita, M.H.; Nashawati, A.; Amin, Y.; Al-Akel, B.

2004-12-01

In this study, 18 kind of cigarettes and five kinds of molasses consumed by Syrians were collected and analyzed for radioactivity in order to estimate the internal radiation dose caused by 210 Po and 210 Pb intake. Polonium 210 and lead 210 concentrations varied between 4 and 16.4 m Bq/cigarette, while 210 Po distribution ratios in different parts of consumed cigarette were %12, %73, %1.6 in ash, smoke and filter, respectively. In addition, annual intake of 210 Po by a main smoker was varied between 4.4 and 18 Bq/year assuming that the main smoker breathes about 15% of the total 210 Po present in tobacco. Using the values of the annual intake, annual equivalent radiation dose caused by smoking has reached 178 μSv/year. Moreover, mean concentration of 210 Po in nonsmokers and smokers bloods has reached 130 and 97 mBq/l, respectively, while the mean value of 210 Po concentration was relatively higher and reached 176 and 155 mBq/l in smokers and non smoker bloods, respectively (Authors)

Howard Hughes Medical Institute dose assessment survey

International Nuclear Information System (INIS)

O'Brien, S.L.; McDougall, M.M.; Barkley, W.E.

1996-01-01

Biomedical science researchers often express frustration that health physics practices vary widely between individual institutions. A survey examining both internal and external dose assessment practices was devised and mailed to fifty institutions supporting biomedical science research. The results indicate that health physics dose assessment practices and policies are highly variable. Factors which may contribute to the degree of variation are discussed. 2 tabs

THE URINE PROTEOME FOR RADIATION BIODOSIMETRY: EFFECT OF TOTAL BODY VERSUS LOCAL KIDNEY IRRADIATION

Science.gov (United States)

Sharma, Mukut; Halligan, Brian D.; Wakim, Bassam T.; Savin, Virginia J.; Cohen, Eric P.; Moulder, John E.

2009-01-01

Victims of nuclear accidents or radiological terrorism are likely to receive varying doses of ionizing radiation inhomogeneously distributed over the body. Early biomarkers may be useful in determining organ-specific doses due to total body irradiation (TBI) or partial body irradiation. We used liquid chromatography and mass spectrometry to compare the effect of TBI and local kidney irradiation (LKI) on the rat urine proteome using a single 10 Gy dose of X-rays. Both TBI and LKI altered the urinary protein profile within 24 hours with noticeable differences in Gene Ontology categories. Some proteins including fetuin-B, tissue kallikrein, beta-glucuronidase, vitamin D-dependent calcium binding protein and chondroitin sulfate proteoglycan NG2 were detected only in the TBI group. Some other proteins including major urinary protein-1, RNA binding protein 19, neuron navigator, Dapper homolog 3, WD repeat and FYVE domain containing protein 3, sorting nexin-8, ankycorbin and aquaporin were detected only in the LKI group. Protease inhibitors and kidney proteins were more abundant (fraction of total scans) in the LKI group. Up/Uc ratio and urinary albumin abundance decreased in both TBI and LKI groups. Several markers of acute kidney injury were not detectable in either irradiated group. Present data indicate that abundance and number of proteins may follow opposite trends. These novel findings demonstrate intriguing differences between TBI and LKI, and suggest that urine proteome may be useful in determining organ-specific changes caused by partial body irradiation. PMID:20065682

Hyperfractionated high-dose total body irradiation in bone marrow transplantation for Ph{sup 1}-positive acute lymphoblastic leukemia

Energy Technology Data Exchange (ETDEWEB)

Kikuchi, Akira; Ebihara, Yasuhiro; Mitsui, Tetsuo [Tokyo Univ. (Japan). Hospital of the Institute of Medical Science] [and others

1998-12-01

In two cases of Philadelphia-positive childhood acute lymphoblastic leukemia (Ph{sup 1} ALL), we performed allogeneic bone marrow transplantation (AlloBMT) with preconditioning regimen, including hyperfractionated high-dose total body irradiation (TBI) (13.5 Gy, in 9 fractions). Their disease statuses at BMT were hematological relapse in case 1 and molecular relapse in case 2. Bone marrow donors were unrelated in case 1, and HLA was a partially mismatched mother in case 2. Regimen-related toxicity was tolerable in both cases. Hematological recovery was rapid, and engraftment was obtained on day 14 in case 1 and on day 12 in case 2. BCR/ABL message in bone marrow disappeared on day 89 in case 1 and on day 19 in case 2 and throughout their subsequent clinical courses. Although short-term MTX and Cy-A continuous infusion were used for GVHD prophylaxis, grade IV GVHD was observed in case 1 and grade III in case 2. Both cases experienced hemorrhagic cystitis because of adenovirus type 11 infection. Although case 1 died of interstitial pneumonitis on day 442, case 2 has been free of disease through day 231. AlloBMT for Ph{sup 1} ALL with preconditioning regimen including hyperfractionated high-dose TBI is considered to be worth further investigation. (author)

CSF total protein

Science.gov (United States)

CSF total protein is a test to determine the amount of protein in your spinal fluid, also called cerebrospinal fluid (CSF). ... The normal protein range varies from lab to lab, but is typically about 15 to 60 milligrams per deciliter (mg/dL) ...

Biological responses to low dose rate gamma radiation

International Nuclear Information System (INIS)

Magae, Junji; Ogata, Hiromitsu

2003-01-01

Linear non-threshold (LNT) theory is a basic theory for radioprotection. While LNT dose not consider irradiation time or dose-rate, biological responses to radiation are complex processes dependent on irradiation time as well as total dose. Moreover, experimental and epidemiological studies that can evaluate LNT at low dose/low dose-rate are not sufficiently accumulated. Here we analyzed quantitative relationship among dose, dose-rate and irradiation time using chromosomal breakage and proliferation inhibition of human cells as indicators of biological responses. We also acquired quantitative data at low doses that can evaluate adaptability of LNT with statistically sufficient accuracy. Our results demonstrate that biological responses at low dose-rate are remarkably affected by exposure time, and they are dependent on dose-rate rather than total dose in long-term irradiation. We also found that change of biological responses at low dose was not linearly correlated to dose. These results suggest that it is necessary for us to create a new model which sufficiently includes dose-rate effect and correctly fits of actual experimental and epidemiological results to evaluate risk of radiation at low dose/low dose-rate. (author)

Total integrated dose testing of solid-state scientific CD4011, CD4013, and CD4060 devices by irradiation with CO-60 gamma rays

Science.gov (United States)

Dantas, A. R. V.; Gauthier, M. K.; Coss, J. R.

1985-01-01

The total integrated dose response of three CMOS devices manufactured by Solid State Scientific has been measured using CO-60 gamma rays. Key parameter measurements were made and compared for each device type. The data show that the CD4011, CD4013, and CD4060 produced by this manufacturers should not be used in any environments where radiation levels might exceed 1,000 rad(Si).

Marijuana smoking: effects of varying puff volume and breathhold duration.

Science.gov (United States)

Azorlosa, J L; Greenwald, M K; Stitzer, M L

1995-02-01

Two studies were conducted to quantify biological and behavioral effects resulting from exposure to controlled doses of marijuana smoke. In one study, puff volume (30, 60 and 90 ml) and in a second study, breathhold duration (0, 10 and 20 sec) were systematically varied while holding constant other smoking topography parameters (number of puffs = 10, interpuff interval = 60 sec and inhalation volume = 25% of vital capacity). Each study also varied levels of delta 9-tetrahydro-cannabinol marijuana cigarette content (1.75% and 3.55%). Regular marijuana users served as subjects (n = 7 in each experiment). Subjects smoked 10 puffs in each of six sessions; a seventh, nonsmoking session (all measures recorded at the same times as in active smoking sessions) served as a control. Variations in puff volume produced significant dose-related changes in postsmoking plasma delta 9-tetrahydro-cannabinol levels, carbon monoxide boost and subjective effects (e.g., "high"). In contrast, breathholding for 10 or 20 sec versus 0 sec increased plasma delta 9-tetrahydro-cannabinol levels but not CO boost or subjective effects. Task performance measures were not reliably influenced by marijuana smoke exposure within the dosing ranges examined. These findings confirm the utility of the controlled smoking technology, support the notion that cumulative puff volume systematically influences biological exposure and subjective effects, but cast doubt on the common belief that prolonged breathholding of marijuana smoke enhances classical subjective effects associated with its reinforcing value in humans.

Ozonation for source treatment of pharmaceuticals in hospital wastewater - ozone lifetime and required ozone dose

DEFF Research Database (Denmark)

Hansen, Kamilla Marie Speht; Spiliotopoulou, Aikaterini; Chhetri, Ravi Kumar

2016-01-01

Ozonation aimed at removing pharmaceuticals was studied in an effluent from an experimental pilot system using staged moving bed biofilm reactor (MBBR) tanks for the optimal biological treatment of wastewater from a medical care unit of Aarhus University Hospital. Dissolved organic carbon (DOC......) and pH in samples varied considerably, and the effect of these two parameters on ozone lifetime and the efficiency of ozone in removing pharmaceuticals were determined. The pH in the effluent varied from 5.0 to 9.0 resulting in approximately a doubling of the required ozone dose at the highest p......H for each pharmaceutical. DOC varied from 6 to 20 mg-DOC/L. The ozone required for removing each pharmaceutical, varied linearly with DOC and thus, ozone doses normalized to DOC (specific ozone dose) agreed between water samples (typically within 15%). At neutral pH the specific ozone dose required...

Collagen synthesis in CBA mouse heart after total thoracic irradiation

International Nuclear Information System (INIS)

Murray, J.C.; Parkins, C.S.; Institute of Cancer Research, Sutton

1988-01-01

CBA mice were irradiated to the whole thorax with single doses of 240 kVp X-rays in the dose range 8-16 Gy. Collagen and total protein synthesis rates in the heart were measured at 2-monthly intervals using a radio-isotope incorporation techniques. Doses of 10 Gy or greater caused a slight increase in collagen synthesis, followed by significantly reduced collagen synthesis by 16 weeks or longer after treatment. The depression in synthesis appeared correspondingly earlier with increasing dose. Total protein synthesis in heart followed similar patterns although changes were not statistically significant, indicating that the changes reflected alterations to collagen synthesis specifally, and not protein synthesis in geneal. Total hydroxyproline measurements showed no significant changes in heart collagen at any time as a result of X-irradiation. 18 refs.; 7 figs

Patient dose measurement and dose reduction in chest radiography

Directory of Open Access Journals (Sweden)

Milatović Aleksandra A.

2014-01-01

Full Text Available Investigations presented in this paper represent the first estimation of patient doses in chest radiography in Montenegro. In the initial stage of our study, we measured the entrance surface air kerma and kerma area product for chest radiography in five major health institutions in the country. A total of 214 patients were observed. We reported the mean value, minimum and third quartile values, as well as maximum values of surface air kerma and kerma area product of patient doses. In the second stage, the possibilities for dose reduction were investigated. Mean kerma area product values were 0.8 ± 0.5 Gycm2 for the posterior-anterior projection and 1.6 ± 0.9 Gycm2 for the lateral projection. The max/min ratio for the entrance surface air kerma was found to be 53 for the posterior-anterior projection and 88 for the lateral projection. Comparing the results obtained in Montenegro with results from other countries, we concluded that patient doses in our medical centres are significantly higher. Changes in exposure parameters and increased filtration contributed to a dose reduction of up to 36% for posterior-anterior chest examinations. The variability of the estimated dose values points to a significant space for dose reduction throughout the process of radiological practice optimisation.

Oral Tranexamic Acid Reduces Transfusions in Total Knee Arthroplasty.

Science.gov (United States)

Perreault, Roger E; Fournier, Christine A; Mattingly, David A; Junghans, Richard P; Talmo, Carl T

2017-10-01

Tranexamic acid (TXA) reduces intraoperative blood loss and transfusions in patients undergoing total knee arthroplasty. Although numerous studies demonstrate the efficacy of intravenous and topical TXA in these patients, few demonstrate the effectiveness and appropriate dosing recommendations of oral formulations. A retrospective cohort study was performed to evaluate differences in transfusion requirements in patients undergoing primary unilateral total knee arthroplasty with either no TXA (n = 866), a single-dose of oral TXA (n = 157), or both preoperative and postoperative oral TXA (n = 1049). Secondary outcomes included postoperative hemoglobin drop, total units transfused, length of stay, drain output, and cell salvage volume. Transfusion rates decreased from 15.4% in the no-oral tranexamic acid (OTA) group to 9.6% in the single-dose OTA group (P < .001) and 7% in the 2-dose group (P < .001), with no difference in transfusion rates between the single- and 2-dose groups (P = .390). In addition, postoperative hemoglobin drop was reduced from 4.2 g/dL in the no-OTA group to 3.5 g/dL in the single-dose group (P < .01) and to 3.4 g/dL in the 2-dose group (P < .01), without a difference between the single- and 2-dose groups (P = .233). OTA reduces transfusions, with greater ease of administration and improved cost-effectiveness relative to other forms of delivery. Copyright © 2017 Elsevier Inc. All rights reserved.

Physiological and immunological changes following exposure to low versus high-dose ionizing irradiation; comparative analysis with dose rate and cumulative dose

International Nuclear Information System (INIS)

Heesun, Kim; Heewon, Jang; Soungyeon, Song; Shinhye, Oh; Cukcheul, Shin; Meeseon, Jeong; Chasoon, Kim; Kwnaghee, Yang; Seonyoung, Nam; Jiyoung, Kim; Youngwoo, Jin; Changyoung, Cha

2008-01-01

Full text: While high-dose of ionizing radiation is generally harmful and causes damage to living organisms some reports suggest low-dose of radiation may not be as damaging as previously thought. Despite increasing evidence regarding the protective effect of low-dose radiation, no studies have directly compared the exact dose-response pattern by high- and low-dose of radiation exposed at high-and low-dose rate. This study aims to explore the cellular and molecular changes in mice exposed to low- and high-dose of radiation exposed at low- and high-dose rate. When C57BL/6 mice (Female, 6 weeks) were exposed at high-dose rate, 0.8 Gy/min, no significant change on the level of WBC, RBC, or platelets was observed up to total dose of 0.5 Gy. However, 2 Gy of radiation caused dramatic reduction in the level of white blood cells (WBC) and platelets. This reduction was accompanied by increased DNA damage in hematopoietic environments. The reduction of WBC was mainly due to the reduction in the number of CD4+ T cells and CD19+ B cells. CD8+ T cells and NK cells appeared to be relatively resistant to high-dose of radiation. This change was also accompanied by the reduction of T- and B- progenitor cells in the bone marrow. In contrast, no significant changes of the number of CD4+ T, CD8+ T, NK, and B cells were observed in the spleen of mice exposed at low-dose-rate (0.7 m Gy/h or 3.95 mGy/h) for up to 2 Gy, suggesting that low-dose radiation does not alter cellular distribution in the spleen. Nevertheless, mice exposed to low-dose radiation exhibited elevation of VEGF, MCP-1, IL-4, Leptin, IL-3, and Tpo in the peripheral blood and slight increases in MIP-2, RANTES, and IL-2 in the spleen. This suggests that chronic γ-radiation can stimulate immune function without causing damage to the immune components of the body. Taken together, these data indicate hormesis of low-dose radiation, which could be attributed to the stimulation of immune function. Dose rate rather than total