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Sample records for dose study evaluating

  1. A dose error evaluation study for 4D dose calculations

    Science.gov (United States)

    Milz, Stefan; Wilkens, Jan J.; Ullrich, Wolfgang

    2014-10-01

    Previous studies have shown that respiration induced motion is not negligible for Stereotactic Body Radiation Therapy. The intrafractional breathing induced motion influences the delivered dose distribution on the underlying patient geometry such as the lung or the abdomen. If a static geometry is used, a planning process for these indications does not represent the entire dynamic process. The quality of a full 4D dose calculation approach depends on the dose coordinate transformation process between deformable geometries. This article provides an evaluation study that introduces an advanced method to verify the quality of numerical dose transformation generated by four different algorithms. The used transformation metric value is based on the deviation of the dose mass histogram (DMH) and the mean dose throughout dose transformation. The study compares the results of four algorithms. In general, two elementary approaches are used: dose mapping and energy transformation. Dose interpolation (DIM) and an advanced concept, so called divergent dose mapping model (dDMM), are used for dose mapping. The algorithms are compared to the basic energy transformation model (bETM) and the energy mass congruent mapping (EMCM). For evaluation 900 small sample regions of interest (ROI) are generated inside an exemplary lung geometry (4DCT). A homogeneous fluence distribution is assumed for dose calculation inside the ROIs. The dose transformations are performed with the four different algorithms. The study investigates the DMH-metric and the mean dose metric for different scenarios (voxel sizes: 8 mm, 4 mm, 2 mm, 1 mm 9 different breathing phases). dDMM achieves the best transformation accuracy in all measured test cases with 3-5% lower errors than the other models. The results of dDMM are reasonable and most efficient in this study, although the model is simple and easy to implement. The EMCM model also achieved suitable results, but the approach requires a more complex

  2. Field study to evaluate radiation doses in dental practices

    International Nuclear Information System (INIS)

    Panzer, W.; Scheurer, C.

    1984-05-01

    An inexpensive and simple test device was developed and used in a field study to evaluate entrance dose, dose to an intra-oral film, filtration and field size under routine conditions in more than 150 dental practices. The test device consists of two films of different speed and a set of 5 thin copper filters for a filter analytical determination of the radiation quality. Dentists voluntarily participating in the study were asked to expose the test device like they usually do when examining a molar tooth. The main result was the evidence of a significant dose reduction compared to the findings of similar studies performed in 1970 and 1976. This reduction is due to a general shift to lower values and a complete disappearance of values above 45 mGy (5 R) which in 1970 were still more than 15%. In the same way the number of facilities showing insufficient filtration or collimation had decreased. Nevertheless, a large spread of dose values could still be observed, ranging from less than 0.45 mGy (50 mR) to more than 26 mGy (3 R), for the entrance dose. The most striking result, however, was that such an important parameter like the speed of the films used at the respective unit turned out to have no impact on the entrance dose. (orig./HP)

  3. Design study on dose evaluation method for employees at severe accident

    International Nuclear Information System (INIS)

    Yoshida, Yoshitaka; Irie, Takashi; Kohriyama, Tamio; Kudo, Seiichi; Nishimura, Kazuya

    2001-01-01

    When we assume a severe accident in a nuclear power plant, it is required for rescue activity in the plant, accident management, repair work of failed parts and evaluation of employees to obtain radiation dose rate distribution or map in the plant and estimated dose value for the above works. However it might be difficult to obtain them accurately along the progress of the accident, because radiation monitors are not always installed in the areas where the accident management is planned or the repair work is thought for safety-related equipments. In this work, we analyzed diffusion of radioactive materials in case of a severe accident in a pressurized water reactor plant, investigated a method to obtain radiation dose rate in the plant from estimated radioactive sources, made up a prototype analyzing system by modeling a specific part of components and buildings in the plant from this design study on dose evaluation method for employees at severe accident, and then evaluated its availability. As a result, we obtained the followings: (1) A new dose evaluation method was established to predict the radiation dose rate in any point in the plant during a severe accident scenario. (2) This evaluation of total dose including moving route and time for the accident management and the repair work is useful for estimating radiation dose limit for these actions of the employees. (3) The radiation dose rate map is effective for identifying high radiation areas and for choosing a route with lower radiation dose rate. (author)

  4. Design study on dose evaluation method for employees at severe accident

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, Yoshitaka; Irie, Takashi; Kohriyama, Tamio [Institute of Nuclear Safety Systems Inc., Mihama, Fukui (Japan); Kudo, Seiichi [Mitsubishi Heavy Industries Ltd., Tokyo (Japan); Nishimura, Kazuya [Computer Software Development Co., Ltd., Tokyo (Japan)

    2001-09-01

    When we assume a severe accident in a nuclear power plant, it is required for rescue activity in the plant, accident management, repair work of failed parts and evaluation of employees to obtain radiation dose rate distribution or map in the plant and estimated dose value for the above works. However it might be difficult to obtain them accurately along the progress of the accident, because radiation monitors are not always installed in the areas where the accident management is planned or the repair work is thought for safety-related equipments. In this work, we analyzed diffusion of radioactive materials in case of a severe accident in a pressurized water reactor plant, investigated a method to obtain radiation dose rate in the plant from estimated radioactive sources, made up a prototype analyzing system by modeling a specific part of components and buildings in the plant from this design study on dose evaluation method for employees at severe accident, and then evaluated its availability. As a result, we obtained the followings: (1) A new dose evaluation method was established to predict the radiation dose rate in any point in the plant during a severe accident scenario. (2) This evaluation of total dose including moving route and time for the accident management and the repair work is useful for estimating radiation dose limit for these actions of the employees. (3) The radiation dose rate map is effective for identifying high radiation areas and for choosing a route with lower radiation dose rate. (author)

  5. Design study on dose evaluation method for employees at severe accident

    International Nuclear Information System (INIS)

    Yoshida, Yoshitaka; Irie, Takashi; Kohriyama, Tamio; Kudo, Seiichi; Nishimura, Kazuya

    2002-01-01

    If a severe accident occurs in a pressurized water reactor plant, it is required to estimate dose values of operators engaged in emergency such as accident management, repair of failed parts. However, it might be difficult to measure radiation dose rate during the progress of an accident, because radiation monitors are not always installed in areas where the emergency activities are required. In this study, we analyzed the transport of radioactive materials in case of a severe accident, investigated a method to obtain radiation dose rate in the plant from estimated radioactive sources, made up a prototype analyzing system from this design study, and then evaluated its availability. As a result, we obtained the following: (1) A new dose evaluation method was established to predict the radiation dose rate at any point in the plant during a severe accident scenario. (2) This evaluation of total dose including access route and time for emergency activities is useful for estimating radiation dose limit for these employee actions. (3) The radiation dose rate map is effective for identifying high radiation areas and for choosing a route with lower radiation dose rate. (author)

  6. Study on the evaluation of radiation doses in dental radiography. Doses and risks due to dental full mouth examination

    Energy Technology Data Exchange (ETDEWEB)

    Sugimoto, K [Kanagawa Dental Coll., Yokosuka (Japan)

    1980-09-01

    Radiation doses and possible biological risks due to dental full mouth examination (adult: 10-film technique, child: 6-film technique) were evaluated based on preliminary experiments and statistical surveillance of patients' records. Dosimetrical studies were performed by using head and neck phantoms and a dental x-ray tube. Radiation doses were measured by x-ray films and thermoluminescence dosimeters. For the obtained doses of skin, eyes, thyroid gland and bone marrow, the biological risk of leukemia and thyroid cancer was discussed on the statistical basis of patients at Kanagawa Dental College Hospital. The major findings were as follows: The total number of patients who recieved full mouth x-ray examination at Kanagawa Dental College Hospital in 1978 was 1,099. The number of male patients was 382 (3,804 films) and that of female patients was 717 (7,138 films). In both sexes, the number of patients was the greatest in the group of 8 - 14 years of age. The collective doses of bone marrow due to full mouth 10-film examination performed at Kanagawa Dental College Hospital in 1978 were approximately 6.0 rad, which could induce leukemia with a probability of 1/8,000. The collective doses of thyroid gland were approximately 13 rad, which could induce lethal thyroid cancer with a probability of 1/15,000. The radiation dose due to the dental radiography for examination at Kanagawa Dental College Hospital was proved to be apparently below the level that could actually induce radiation injuries. But the collective radiation doses due to dental examination in Japan as a whole were approximately 8,000 times greater than that in Kanagawa Dental College Hospital.

  7. Evaluation of the image quality criteria and study of doses in a mammography department

    International Nuclear Information System (INIS)

    Alcantara, Marcela Costa

    2009-01-01

    The mammographic image quality criteria published by European Commission were implemented in three mammography equipment of a same radiology department in a hospital of Sao Paulo city. Among the mammography equipment, two use the screen-film system and one of them uses the indirect digital system. During the data collection, it was noted the need to conduct a study about image rejection in each mammography equipment. Therefore, this study was realized and, after that, the results in each mammography equipment of image rejection and image percentage that present each quality criterion it were compared. At the same time of this studies, it was realized other study about surface entrance dose and average glandular dose. These doses it was estimated based on different methods published by different groups of researcher, for all combinations anode filter available in the equipment. To estimate the surface entrance dose following the methodology published in Avenue's' guide and the average glandular dose following the Wu' methodology, it was developed a phantom, in different thicknesses of acrylic, to simulate a breast. Finally, the image quality it was associated with the dose received by patient. The digital equipment shows better results in the evaluation of quality criteria, lower rate of image rejection and lower values of average glandular dose and surface entrance dose in all methods studied. But it is not sufficient, because is not adequate for patients with great breast. (author)

  8. A study of different dose calculation methods and the impact on the dose evaluation protocol in lung stereotactic radiation therapy

    International Nuclear Information System (INIS)

    Takada, Takahiro; Furuya, Tomohisa; Ozawa, Shuichi; Ito, Kana; Kurokawa, Chie; Karasawa, Kumiko; Miura, Kohei

    2008-01-01

    AAA (analytical anisotropic algorithm) dose calculation, which shows a better performance for heterogeneity correction, was tested for lung stereotactic radiation therapy (SBRT) in comparison to conventional PBC (pencil beam convolution method) to evaluate its impact on tumor dose parameters. Eleven lung SBRT patients who were treated with photon 4 MV beams in our department between April 2003 and February 2007 were reviewed. Clinical target volume (CTV) was delineated including the spicula region on planning CT images. Planning target volume (PTV) was defined by adding the internal target volume (ITV) and set-up margin (SM) of 5 mm from CTV, and then an multileaf collimator (MLC) penumbra margin of another 5 mm was also added. Six-port non-coplanar beams were employed, and a total prescribed dose of 48 Gy was defined at the isocenter point with four fractions. The entire treatment for an individual patient was completed within 8 days. Under the same prescribed dose, calculated dose distribution, dose volume histogram (DVH), and tumor dose parameters were compared between two dose calculation methods. In addition, the fractionated prescription dose was repeatedly scaled until the monitor units (MUs) calculated by AAA reached a level of MUs nearly identical to those achieved by PBC. AAA resulted in significantly less D95 (irradiation dose that included 95% volume of PTV) and minimal dose in PTV compared to PBC. After rescaling of each MU for each beam in the AAA plan, there was no revision of the isocenter of the prescribed dose required. However, when the PTV volume was less than 20 cc, a 4% lower prescription resulted in nearly identical MUs between AAA and PBC. The prescribed dose in AAA should be the same as that in PBC, if the dose is administered at the isocenter point. However, planners should compare DVHs and dose distributions between AAA and PBC for a small lung tumor with a PTV volume less than approximately 20 cc. (author)

  9. Study on the evaluation method of radiation dose rate around spent fuel shipping casks

    International Nuclear Information System (INIS)

    Yamakoshi, Hisao

    1986-01-01

    This study aims at developing a simple calculation method which can evaluate radiation dose rate around casks with high accuracy in a short time. The method is based on a concept of the radiation shielding characteristics of cask walls. The concept was introduced to replace for ordinary radiation shielding calculation which requires a long calculation time and a large memory capacity of a computer in the matrix calculation. For the purpose of verifying the accuracy and reliability of the new method, it was applied to the analysis of the dose rate distribution around actual casks, which had been measured. The results of the analysis revealed that the newly proposed method was excellent for the forecast of radiation dose rate distribution around casks in view of the accuracy and calculation time. The short calculation time and high accuracy by the proposed method were attained by dividing the whole procedure of ordinary fine radiation shielding calculation into the calculation of radiation dose rate on a cask surface by the matrix expression of the characteristic function and the calculation of dose rate distribution using the simple analytical expression of dose rate distribution around casks. The effect of the heterogeneous array of spent fuel in different burnup state on dose rate distribution around casks was evaluated by this method. (Kako, I.)

  10. Evaluation of radiation dose in pediatric head CT examination: a phantom study

    Science.gov (United States)

    Norhasrina Nik Din, Nik; Zainon, Rafidah; Rahman, Ahmad Taufek Abdul

    2018-01-01

    The aim of this study was to evaluate the radiation dose in pediatric head Computed Tomography examination. It was reported that decreasing tube voltage in CT examination can reduce the dose to patients significantly. A head phantom was scanned with dual-energy CT at 80 kV and 120 kV. The tube current was set using automatic exposure control mode and manual setting. The pitch was adjusted to 1.4, 1.45 and 1.5 while the slice thickness was set at 5 mm. The dose was measured based on CT Dose Index (CTDI). Results from this study have shown that the image noise increases substantially with low tube voltage. The average dose was 2.60 mGy at CT imaging parameters of 80 kV and 10 - 30 mAs. The dose increases up to 17.19 mGy when the CT tube voltage increases to 120 kV. With the reduction of tube voltage from 120 kV to 80 kV, the radiation dose can be reduced by 12.1% to 15.1% without degradation of contrast-to-noise ratio.

  11. Correction for FDG PET dose extravasations: Monte Carlo validation and quantitative evaluation of patient studies

    Energy Technology Data Exchange (ETDEWEB)

    Silva-Rodríguez, Jesús, E-mail: jesus.silva.rodriguez@sergas.es; Aguiar, Pablo, E-mail: pablo.aguiar.fernandez@sergas.es [Fundación Ramón Domínguez, Santiago de Compostela, Galicia (Spain); Servicio de Medicina Nuclear, Complexo Hospitalario Universidade de Santiago de Compostela (USC), 15782, Galicia (Spain); Grupo de Imaxe Molecular, Instituto de Investigación Sanitarias (IDIS), Santiago de Compostela, 15706, Galicia (Spain); Sánchez, Manuel; Mosquera, Javier; Luna-Vega, Víctor [Servicio de Radiofísica y Protección Radiológica, Complexo Hospitalario Universidade de Santiago de Compostela (USC), 15782, Galicia (Spain); Cortés, Julia; Garrido, Miguel [Servicio de Medicina Nuclear, Complexo Hospitalario Universitario de Santiago de Compostela, 15706, Galicia, Spain and Grupo de Imaxe Molecular, Instituto de Investigación Sanitarias (IDIS), Santiago de Compostela, 15706, Galicia (Spain); Pombar, Miguel [Servicio de Radiofísica y Protección Radiológica, Complexo Hospitalario Universitario de Santiago de Compostela, 15706, Galicia (Spain); Ruibal, Álvaro [Servicio de Medicina Nuclear, Complexo Hospitalario Universidade de Santiago de Compostela (USC), 15782, Galicia (Spain); Grupo de Imaxe Molecular, Instituto de Investigación Sanitarias (IDIS), Santiago de Compostela, 15706, Galicia (Spain); Fundación Tejerina, 28003, Madrid (Spain)

    2014-05-15

    Purpose: Current procedure guidelines for whole body [18F]fluoro-2-deoxy-D-glucose (FDG)-positron emission tomography (PET) state that studies with visible dose extravasations should be rejected for quantification protocols. Our work is focused on the development and validation of methods for estimating extravasated doses in order to correct standard uptake value (SUV) values for this effect in clinical routine. Methods: One thousand three hundred sixty-seven consecutive whole body FDG-PET studies were visually inspected looking for extravasation cases. Two methods for estimating the extravasated dose were proposed and validated in different scenarios using Monte Carlo simulations. All visible extravasations were retrospectively evaluated using a manual ROI based method. In addition, the 50 patients with higher extravasated doses were also evaluated using a threshold-based method. Results: Simulation studies showed that the proposed methods for estimating extravasated doses allow us to compensate the impact of extravasations on SUV values with an error below 5%. The quantitative evaluation of patient studies revealed that paravenous injection is a relatively frequent effect (18%) with a small fraction of patients presenting considerable extravasations ranging from 1% to a maximum of 22% of the injected dose. A criterion based on the extravasated volume and maximum concentration was established in order to identify this fraction of patients that might be corrected for paravenous injection effect. Conclusions: The authors propose the use of a manual ROI based method for estimating the effectively administered FDG dose and then correct SUV quantification in those patients fulfilling the proposed criterion.

  12. Diagnosis of cerebral metastases by means of standard doses of Gadobutrol versus a high-dose protocol. Intraindividual evaluation of a phase-II high-dose study

    International Nuclear Information System (INIS)

    Vogl, T.J.; Friebe, C.E.; Balzer, T.; Mack, M.G.; Steiner, S.; Schedel, H.; Pegios, W.; Lanksch, W.; Banzer, D.; Felix, R.

    1995-01-01

    In a clinical phase-II study 20 patients who had been diagnosed as having brain metastases with CT or MRT were studied prospectively with Gadobutrol, a new nonionic, low osmolality contrast agent. Each patient received an initial injection of 0.1 mmol/kg body weight and an additional dose of 0.2 mmol/kg Gadobutrol 10 min later. Spinecho images were obtained before and after the two applications of Gadobutrol. Dynamic scanning (Turbo-FLASH) was performed for 3 min after each injection of the contrast agent. Both quantitative and qualitative data were intraindividually evaluated. The primary tumor was a bronchial carcinoma in 11 cases; in 9 other cases there were different primary tumors. Forty-eight hours after the use of Gadobutrol there were no adverse signs in the clinical examination, vital signs or blood and urine chemistry. Statistical analysis (Friedman test and Wilcoxon test) of the C/N ratios between tumor and white matter, percentage enhancement, and visual assessment rating revealed statistically significant superiority of high-dose Gadobutrol injection in comparison to the standard dose. The percentage enhancement increased on average from 104% after 0.1 mmol/kg to 162% after 0.3 mmol/kg Gadobutrol. Qualitative delineation and contrast of the lesions increased significantly. The use of high-dose Gadobutrol improved the detection of 36 additional lesions in 6 patients. (orig./VHE) [de

  13. Regulatory Forum Opinion Piece*: Retrospective Evaluation of Doses in the 26-week Tg.rasH2 Mice Carcinogenicity Studies: Recommendation to Eliminate High Doses at Maximum Tolerated Dose (MTD) in Future Studies.

    Science.gov (United States)

    Paranjpe, Madhav G; Denton, Melissa D; Vidmar, Tom J; Elbekai, Reem H

    2015-07-01

    High doses in Tg.rasH2 carcinogenicity studies are usually set at the maximum tolerated dose (MTD), although this dose selection strategy has not been critically evaluated. We analyzed the body weight gains (BWGs), mortality, and tumor response in control and treated groups of 29 Tg.rasH2 studies conducted at BioReliance. Based on our analysis, it is evident that the MTD was exceeded at the high and/or mid-doses in several studies. The incidence of tumors in high doses was lower when compared to the low and mid-doses of both sexes. Thus, we recommend that the high dose in male mice should not exceed one-half of the estimated MTD (EMTD), as it is currently chosen, and the next dose should be one-fourth of the EMTD. Because females were less sensitive to decrements in BWG, the high dose in female mice should not exceed two-third of EMTD and the next dose group should be one-third of EMTD. If needed, a third dose group should be set at one-eighth EMTD in males and one-sixth EMTD in females. In addition, for compounds that do not show toxicity in the range finding studies, a limit dose should be applied for the 26-week carcinogenicity studies. © 2014 by The Author(s).

  14. A study on the evaluation of radiation doses in dental radiography

    International Nuclear Information System (INIS)

    Sugimoto, Koju

    1980-01-01

    Radiation doses and possible biological risks due to dental full mouth examination (adult: 10-film technique, child: 6-film technique) were evaluated based on preliminary experiments and statistical surveillance of patients' records. Dosimetrical studies were performed by using head and neck phantoms and a dental x-ray tube. Radiation doses were measured by x-ray films and thermoluminescence dosimeters. For the obtained doses of skin, eyes, thyroid gland and bone marrow, the biological risk of leukemia and thyroid cancer was discussed on the statistical basis of patients at Kanagawa Dental College Hospital. The major findings were as follows: The total number of patients who recieved full mouth x-ray examination at Kanagawa Dental College Hospital in 1978 was 1,099. The number of male patients was 382 (3,804 films) and that of female patients was 717 (7,138 films). In both sexes, the number of patients was the greatest in the group of 8 - 14 years of age. The collective doses of bone marrow due to full mouth 10-film examination performed at Kanagawa Dental College Hospital in 1978 were approximately 6.0 rad, which could induce leukemia with a probability of 1/8,000. The collective doses of thyroid gland were approximately 13 rad, which could induce lethal thyroid cancer with a probability of 1/15,000. The radiation dose due to the dental radiography for examination at Kanagawa Dental College Hospital was proved to be apparently below the level that could actually induce radiation injuries. But the collective radiation doses due to dental examination in Japan as a whole were approximately 8,000 times greater than that in Kanagawa Dental College Hospital. (J.P.N.)

  15. Performance evaluation of iterative reconstruction algorithms for achieving CT radiation dose reduction — a phantom study

    Science.gov (United States)

    Dodge, Cristina T.; Tamm, Eric P.; Cody, Dianna D.; Liu, Xinming; Jensen, Corey T.; Wei, Wei; Kundra, Vikas

    2016-01-01

    The purpose of this study was to characterize image quality and dose performance with GE CT iterative reconstruction techniques, adaptive statistical iterative reconstruction (ASiR), and model‐based iterative reconstruction (MBIR), over a range of typical to low‐dose intervals using the Catphan 600 and the anthropomorphic Kyoto Kagaku abdomen phantoms. The scope of the project was to quantitatively describe the advantages and limitations of these approaches. The Catphan 600 phantom, supplemented with a fat‐equivalent oval ring, was scanned using a GE Discovery HD750 scanner at 120 kVp, 0.8 s rotation time, and pitch factors of 0.516, 0.984, and 1.375. The mA was selected for each pitch factor to achieve CTDIvol values of 24, 18, 12, 6, 3, 2, and 1 mGy. Images were reconstructed at 2.5 mm thickness with filtered back‐projection (FBP); 20%, 40%, and 70% ASiR; and MBIR. The potential for dose reduction and low‐contrast detectability were evaluated from noise and contrast‐to‐noise ratio (CNR) measurements in the CTP 404 module of the Catphan. Hounsfield units (HUs) of several materials were evaluated from the cylinder inserts in the CTP 404 module, and the modulation transfer function (MTF) was calculated from the air insert. The results were confirmed in the anthropomorphic Kyoto Kagaku abdomen phantom at 6, 3, 2, and 1 mGy. MBIR reduced noise levels five‐fold and increased CNR by a factor of five compared to FBP below 6 mGy CTDIvol, resulting in a substantial improvement in image quality. Compared to ASiR and FBP, HU in images reconstructed with MBIR were consistently lower, and this discrepancy was reversed by higher pitch factors in some materials. MBIR improved the conspicuity of the high‐contrast spatial resolution bar pattern, and MTF quantification confirmed the superior spatial resolution performance of MBIR versus FBP and ASiR at higher dose levels. While ASiR and FBP were relatively insensitive to changes in dose and pitch, the spatial

  16. X-ray absorbed doses evaluation on patients under radiological studies

    International Nuclear Information System (INIS)

    Medeiros, Regina Bitelli; Daros, Kellen A.C.

    1996-01-01

    The skin absorbed doses were evaluated on patient submitted to the following x-ray exams : chest, facial sinus, lumbar spine. Thermoluminescent dosimetry was used and a variety of irradiation techniques performed. The results shown considerable differences on the absorbed dose for the various alternative technical conditions

  17. Preliminary study of dose equivalent evaluation for residents in radioactivity contaminated rebar buildings

    International Nuclear Information System (INIS)

    Chen, W.L.; Liao, C.C.; Wang, M.T.; Chen, F. D.

    1998-01-01

    It has recently been found that several resident and office buildings in Taiwan were constructed with 60 Co-contaminated reinforcing steel bar (rebar). Both governmental officials and the residents of such buildings have been concerned about this finding. In order to respond to the situation, the government has adopted a number of remedial measures, including full-scale radiation survey, dose evaluation and physical examinations of residents. This article presents three methods for evaluating the dose equivalents of the residents living in the contaminated rebar buildings by means of γ-ray survey, necklace-type thermoluminescence dosimeters (TLDs) and the human lymphocyte chromosome aberration analyses. The results reveal that the dose evaluation by γ-ray survey is rather conservative. Generally for the residents whose annual dose equivalents are greater than 5 mSv (0.5 rem) by γ-ray survey, the dose equivalents from necklace-type TLDs are only within the range of 20 to 50% of the evaluated values mentioned above. For chromosome analyses, at least 500 lymphocyte cells were scored and analyzed for each resident. Most of the chromosome analysis data show that the dose equivalents received by residents are lower than the detection limit of the method (100 mSv) and quite different from the estimated dose obtained from either γ-ray survey or necklace-type TLD measurements

  18. Results of RELID study 2014-Buenos Aires, Argentina retrospective evaluation of lens injuries and dose

    International Nuclear Information System (INIS)

    Papp, C.; Touzet, R.; Romano-Miller, M.; Descalzo, A.; Michelin, S.; Molinari, A.; Rossini, A.; Di Giorgio, M.; Plotkin, C.; Bodino, G.; Esperanza, G.

    2017-01-01

    High levels of scatter radiation in catheterization laboratories may lead to posterior subcapsular opacities in the lens of the staff. The international Retrospective Evaluation of Lens Injuries and Dose (RELID) was performed in Argentina for the first time in 2010 in the context of the congress of the Latin American Society of Interventional Cardiology (SOLACI) and recently, in 2014, was carried out for the second time (SOLACI-CACI 2014). The 2014 study included 115 participants: interventional cardiologists, technicians and nurses. Posterior subcapsular lens changes typical of ionizing radiation exposure were found in 91.5% of interventional cardiologists, in 77% of technicians and in 100% of nurses, according to the Merriam-Focht scale. This RELID study (Argentina 2014) has particular importance since it allowed the follow-up of 10 professionals evaluated in 2010. The results obtained in the study population highlight the importance of the availability and proper use of the elements of radiation protection, as well as staff training. (authors)

  19. Evaluation of dose components for healthy tissue tolerance studies on dogs at the HFR Petten

    International Nuclear Information System (INIS)

    Watkins, P.; Moss, R.L.; Siefert, A.; Huiskamp, R.; Gavin, P.; Konijnenberg, M.

    1993-01-01

    Before the start of clinical trails of BNCT on glioma patients at the Petten reactor, certain preconditions must be determined. In particular the tolerance of healthy brain tissue exposed to the epithermal neutron beam requires investigation. In these studies, beagle dogs have been subjected to different levels of irradiation and 10 B, the latter in the form of BSH. To support this work a treatment planning tool is being developed to predict the various dose components within the treatment volume. A Monte Carlo code, MCNP, has been used to simulate the particle transport and to predict the different dose rate distributions. The doses rates generated by MCNP are manipulated with a processing code, TREAT, to give irradiation times, peak dose positions and to display the required data in a graphical format. This paper explains the basic methodology used in the system and a practical case is presented for one of the healthy tissue tolerance dogs. Doses, both physical and RBE weighted, have been produced for pre-treatment planning studies

  20. SU-D-204-06: Dose and Image Quality Evaluation of a Low-Dose Slot-Scanning X-Ray System for Pediatric Orthopedic Studies

    International Nuclear Information System (INIS)

    Liu, Z; Hoerner, M; Lamoureux, R; Rill, L; Arreola, M

    2015-01-01

    Purpose: Children in early teens with scoliosis require repeated radiographic exams over a number of years. The EOS (EOS imaging S.A., Paris, France) is a novel low-dose slot-scanning digital radiographic system designed to produce full-spine images of a free-standing patient. The radiation dose and image quality characteristics of the EOS were evaluated relative to those of a Computed Radiography (CR) system for scoliosis imaging. Methods: For dose evaluation, a full-torso anthropomorphic phantom was scanned five times using the default standard clinical protocols for both the EOS and a CR system, which include both posteroanterior and lateral full-spine views. Optically stimulated luminescent dosimeters (OSLDs), also known as nanoDots™ (Landauer, Inc., Glenwood, IL), were placed on the phantom’s surface to measure entrance skin dose. To assess image quality, MTF curves were generated from sampling the noise levels within the high-contrast regions of a line-pair phantom. Vertical and horizontal distortions were measured for the square line-pair phantom with the EOS system to evaluate the effects of geometric magnification and misalignment with the indicated imaging plane. Results: The entrance skin dose was measured to be 0.4 to 1.1 mGy for the EOS, and 0.7 to 3.6 mGy for the CR study. MTF comparison shows that CR greatly outperforms the EOS, despite both systems having a limiting resolution at 1.8 line-pairs per mm. Vertical distortion was unaffected by phantom positioning, because of the EOS slot-scanning geometry. Horizontal distortion increased linearly with miscentering distance. Conclusion: The EOS system resulted in approximately 70% lower radiation dose than CR for full-spine images. Image quality was found to be inferior to CR. Further investigation is required to see if EOS system is an acceptable modality for performing clinically diagnostic scoliosis examinations

  1. SU-D-204-06: Dose and Image Quality Evaluation of a Low-Dose Slot-Scanning X-Ray System for Pediatric Orthopedic Studies

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Z; Hoerner, M; Lamoureux, R; Rill, L; Arreola, M [Univ Florida, Jacksonville Beach, FL (United States)

    2015-06-15

    Purpose: Children in early teens with scoliosis require repeated radiographic exams over a number of years. The EOS (EOS imaging S.A., Paris, France) is a novel low-dose slot-scanning digital radiographic system designed to produce full-spine images of a free-standing patient. The radiation dose and image quality characteristics of the EOS were evaluated relative to those of a Computed Radiography (CR) system for scoliosis imaging. Methods: For dose evaluation, a full-torso anthropomorphic phantom was scanned five times using the default standard clinical protocols for both the EOS and a CR system, which include both posteroanterior and lateral full-spine views. Optically stimulated luminescent dosimeters (OSLDs), also known as nanoDots™ (Landauer, Inc., Glenwood, IL), were placed on the phantom’s surface to measure entrance skin dose. To assess image quality, MTF curves were generated from sampling the noise levels within the high-contrast regions of a line-pair phantom. Vertical and horizontal distortions were measured for the square line-pair phantom with the EOS system to evaluate the effects of geometric magnification and misalignment with the indicated imaging plane. Results: The entrance skin dose was measured to be 0.4 to 1.1 mGy for the EOS, and 0.7 to 3.6 mGy for the CR study. MTF comparison shows that CR greatly outperforms the EOS, despite both systems having a limiting resolution at 1.8 line-pairs per mm. Vertical distortion was unaffected by phantom positioning, because of the EOS slot-scanning geometry. Horizontal distortion increased linearly with miscentering distance. Conclusion: The EOS system resulted in approximately 70% lower radiation dose than CR for full-spine images. Image quality was found to be inferior to CR. Further investigation is required to see if EOS system is an acceptable modality for performing clinically diagnostic scoliosis examinations.

  2. Evolution of radon dose evaluation

    Directory of Open Access Journals (Sweden)

    Fujimoto Kenzo

    2004-01-01

    Full Text Available The historical change of radon dose evaluation is reviewed based on the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR reports. Since 1955, radon has been recognized as one of the important sources of exposure of the general public. However, it was not really understood that radon is the largest dose contributor until 1977 when a new concept of effective dose equivalent was introduced by International Commission on Radiological Protection. In 1982, the dose concept was also adapted by UNSCEAR and evaluated per caput dose from natural radiation. Many researches have been carried out since then. However, lots of questions have remained open in radon problems, such as the radiation weighting factor of 20 for alpha rays and the large discrepancy of risk estimation among dosimetric and epidemiological approaches.

  3. Evaluating the Application of Tissue-Specific Dose Kernels Instead of Water Dose Kernels in Internal Dosimetry : A Monte Carlo Study

    NARCIS (Netherlands)

    Moghadam, Maryam Khazaee; Asl, Alireza Kamali; Geramifar, Parham; Zaidi, Habib

    2016-01-01

    Purpose: The aim of this work is to evaluate the application of tissue-specific dose kernels instead of water dose kernels to improve the accuracy of patient-specific dosimetry by taking tissue heterogeneities into consideration. Materials and Methods: Tissue-specific dose point kernels (DPKs) and

  4. A study to evaluate safety and tolerability of repeated doses of tirasemtiv in patients with amyotrophic lateral sclerosis.

    Science.gov (United States)

    Shefner, Jeremy M; Watson, Mary Lou; Meng, Lisa; Wolff, Andrew A

    2013-12-01

    Abstract Tirasemtiv is a fast skeletal muscle activator that increases the sensitivity of the sarcomere to calcium, increasing the efficiency of muscle contraction when the muscle is stimulated at submaximal contraction frequencies. A previous study showed single doses of tirasemtiv to be well tolerated and associated with potentially important improvements in a variety of functional outcomes. This study determined safety of tirasemtiv when given at doses up to 500 mg daily for three weeks. Tirasemtiv was given as a single daily dose up to 375 mg for two weeks, with and without concomitant riluzole. In a separate cohort, an ascending dose protocol evaluated a total dose of 500 mg daily given in two divided doses. Safety and tolerability were assessed, as well as measures of function, muscle strength and endurance. Results showed that tirasemtiv was well tolerated, with dizziness the most common adverse event. Tirasemtiv approximately doubled the serum concentration of riluzole. Trends were noted for improvement in ALSFRS-R, Maximum Minute Ventilation, and Nasal Inspiratory Pressure. In conclusion, tirasemtiv is well tolerated and can be given safely with a reduced dose of riluzole. Positive trends in multiple exploratory outcome measures support the further study of this agent in ALS.

  5. [Evaluation of Organ Dose Estimation from Indices of CT Dose Using Dose Index Registry].

    Science.gov (United States)

    Iriuchijima, Akiko; Fukushima, Yasuhiro; Ogura, Akio

    Direct measurement of each patient organ dose from computed tomography (CT) is not possible. Most methods to estimate patient organ dose is using Monte Carlo simulation with dedicated software. However, dedicated software is too expensive for small scale hospitals. Not every hospital can estimate organ dose with dedicated software. The purpose of this study was to evaluate the simple method of organ dose estimation using some common indices of CT dose. The Monte Carlo simulation software Radimetrics (Bayer) was used for calculating organ dose and analysis relationship between indices of CT dose and organ dose. Multidetector CT scanners were compared with those from two manufactures (LightSpeed VCT, GE Healthcare; SOMATOM Definition Flash, Siemens Healthcare). Using stored patient data from Radimetrics, the relationships between indices of CT dose and organ dose were indicated as each formula for estimating organ dose. The accuracy of estimation method of organ dose was compared with the results of Monte Carlo simulation using the Bland-Altman plots. In the results, SSDE was the feasible index for estimation organ dose in almost organs because it reflected each patient size. The differences of organ dose between estimation and simulation were within 23%. In conclusion, our estimation method of organ dose using indices of CT dose is convenient for clinical with accuracy.

  6. A study to 3D dose measurement and evaluation for respiratory motion in lung cancer stereotactic body radiotherapy treatment

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Byeong Geol; Choi, Chang Heon; Yun, Il Gyu; Yang, Jin Seong; Lee, Dong Myeong; Park, Ju Mi [Dept. of Radiation Oncology, VHS Medical Center, Seoul (Korea, Republic of)

    2014-06-15

    This study aims to evaluate 3D dosimetric impact for MIP image and each phase image in stereotactic body radiotherapy (SBRT) for lung cancer using volumetric modulated arc therapy (VMAT). For each of 5 patients with non-small-cell pulmonary tumors, a respiration-correlated four dimensional computed tomography (4DCT) study was performed . We obtain ten 3D CT images corresponding to phases of a breathing cycle. Treatment plans were generated using MIP CT image and each phases 3D CT. We performed the dose verification of the TPS with use of the Ion chamber and COMPASS. The dose distribution that were 3D reconstructed using MIP CT image compared with dose distribution on the corresponding phase of the 4D CT data. Gamma evaluation was performed to evaluate the accuracy of dose delivery for MIP CT data and 4D CT data of 5 patients. The average percentage of points passing the gamma criteria of 2 mm/2% about 99%. The average Homogeneity Index difference between MIP and each 3D data of patient dose was 0.03∼0.04. The average difference between PTV maximum dose was 3.30 cGy, The average different Spinal Coad dose was 3.30 cGy, The average of difference with V{sub 20}, V{sub 10}, V{sub 5} of Lung was -0.04%∼2.32%. The average Homogeneity Index difference between MIP and each phase 3D data of all patient was -0.03∼0.03. The average PTV maximum dose difference was minimum for 10% phase and maximum for 70% phase. The average Spain cord maximum dose difference was minimum for 0% phase and maximum for 50% phase. The average difference of V{sub 20}, V{sub 10}, V{sub 5} of Lung show bo certain trend. There is no tendency of dose difference between MIP with 3D CT data of each phase. But there are appreciable difference for specific phase. It is need to study about patient group which has similar tumor location and breathing motion. Then we compare with dose distribution for each phase 3D image data or MIP image data. we will determine appropriate image data for treatment plan.

  7. Study of the heterogeneity effects of lung in the evaluation of absorbed dose in radiotherapy

    International Nuclear Information System (INIS)

    Campos, Luciana Tourinho

    2006-02-01

    The main objective of radiotherapy is to deliver the highest possible dose to the tumour, in order to destroy it, reducing as much as possible the doses to healthy tissues adjacent to the target volume. Therefore, it is necessary to do a planning of the treatment. The more complex is the treatment, the more difficult the planning will be, demanding computation sophisticated methods in its execution, in order to consider the heterogeneities present in the human body. Additionally, with the appearing of new radiotherapeutic techniques, that used irradiation fields of small area, for instance, the intensity modulated radiotherapy, the difficulties for the execution of a reliable treatment planning, became still larger. In this work it was studied the influence of the lung heterogeneity in the planning of the curves of percentage depth dose, PDP, obtained with the Eclipse R planning system for different sizes of irradiation fields, using the correction algorithms for heterogeneities available in the planning system: modified Batho, general Batho and equivalent tissue-air ratio. A thorax phantom, manufactured in acrylic, containing a region made of cork to simulate the lung tissue, was used. The PDP curves generated by the planning system were compared to those obtained by Monte Carlo simulation and with the use of thermoluminescent, TL, dosimetry. It was verified that the algorithms used by the Eclipse R system for the correction of heterogeneity effects are not able to generate correct results for PDP curves in the case of small fields, occurring differences of up to 100%, when the 1x1 cm 2 treatment field is considered. These differences can cause a considerable subdosage in the lung tissue, reducing the possibility of the patient cure. (author)

  8. SU-E-T-427: Feasibility Study for Evaluation of IMRT Dose Distribution Using Geant4-Based Automated Algorithms

    International Nuclear Information System (INIS)

    Choi, H; Shin, W; Testa, M; Min, C; Kim, J

    2015-01-01

    Purpose: For intensity-modulated radiation therapy (IMRT) treatment planning validation using Monte Carlo (MC) simulations, a precise and automated procedure is necessary to evaluate the patient dose distribution. The aim of this study is to develop an automated algorithm for IMRT simulations using DICOM files and to evaluate the patient dose based on 4D simulation using the Geant4 MC toolkit. Methods: The head of a clinical linac (Varian Clinac 2300 IX) was modeled in Geant4 along with particular components such as the flattening filter and the multi-leaf collimator (MLC). Patient information and the position of the MLC were imported from the DICOM-RT interface. For each position of the MLC, a step- and-shoot technique was adopted. PDDs and lateral profiles were simulated in a water phantom (50×50×40 cm 3 ) and compared to measurement data. We used a lung phantom and MC-dose calculations were compared to the clinical treatment planning used at the Seoul National University Hospital. Results: In order to reproduce the measurement data, we tuned three free parameters: mean and standard deviation of the primary electron beam energy and the beam spot size. These parameters for 6 MV were found to be 5.6 MeV, 0.2378 MeV and 1 mm FWHM respectively. The average dose difference between measurements and simulations was less than 2% for PDDs and radial profiles. The lung phantom study showed fairly good agreement between MC and planning dose despite some unavoidable statistical fluctuation. Conclusion: The current feasibility study using the lung phantom shows the potential for IMRT dose validation using 4D MC simulations using Geant4 tool kits. This research was supported by Korea Institute of Nuclear safety and Development of Measurement Standards for Medical Radiation funded by Korea research Institute of Standards and Science. (KRISS-2015-15011032)

  9. Preclinical Study of 68Ga-DOTATOC: Biodistribution Assessment in Syrian Rats and Evaluation of Absorbed Dose in Human Organs.

    Science.gov (United States)

    Naderi, Mojdeh; Zolghadri, Samaneh; Yousefnia, Hassan; Ramazani, Ali; Jalilian, Amir Reza

    2016-01-01

    Gallium-68 DOTA-DPhe 1 -Tyr 3 -Octreotide ( 68 Ga-DOTATOC) has been applied by several European centers for the treatment of a variety of human malignancies. Nevertheless, definitive dosimetric data are yet unavailable. According to the Society of Nuclear Medicine and Molecular Imaging, researchers are investigating the safety and efficacy of this radiotracer to meet Food and Drug Administration requirements. The aim of this study was to introduce the optimized procedure for 68 Ga-DOTATOC preparation, using a novel germanium-68 ( 68 Ge)/ 68 Ga generator in Iran and evaluate the absorbed doses in numerous organs with high accuracy. The optimized conditions for preparing the radiolabeled complex were determined via several experiments by changing the ligand concentration, pH, temperature and incubation time. Radiochemical purity of the complex was assessed, using high-performance liquid chromatography and instant thin-layer chromatography. The absorbed dose of human organs was evaluated, based on biodistribution studies on Syrian rats via Radiation Absorbed Dose Assessment Resource Method. 68 Ga-DOTATOC was prepared with radiochemical purity of >98% and specific activity of 39.6 MBq/nmol. The complex demonstrated great stability at room temperature and in human serum at 37°C at least two hours after preparation. Significant uptake was observed in somatostatin receptor-positive tissues such as pancreatic and adrenal tissues (12.83 %ID/g and 0.91 %ID/g, respectively). Dose estimations in human organs showed that the pancreas, kidneys and adrenal glands received the maximum absorbed doses (0.105, 0.074 and 0.010 mGy/MBq, respectively). Also, the effective absorbed dose was estimated at 0.026 mSv/MBq for 68 Ga-DOTATOC. The obtained results showed that 68 Ga-DOTATOC can be considered as an effective agent for clinical PET imaging in Iran.

  10. Design and statistical considerations for studies evaluating the efficacy of a single dose of the human papillomavirus (HPV) vaccine.

    Science.gov (United States)

    Sampson, Joshua N; Hildesheim, Allan; Herrero, Rolando; Gonzalez, Paula; Kreimer, Aimee R; Gail, Mitchell H

    2018-05-01

    Cervical cancer is a leading cause of cancer mortality in women worldwide. Human papillomavirus (HPV) types 16 and 18 cause about 70% of all cervical cancers. Clinical trials have demonstrated that three doses of either commercially available HPV vaccine, Cervarix ® or Gardasil ®, prevent most new HPV 16/18 infections and associated precancerous lesions. Based on evidence of immunological non-inferiority, 2-dose regimens have been licensed for adolescents in the United States, European Union, and elsewhere. However, if a single dose were effective, vaccine costs would be reduced substantially and the logistics of vaccination would be greatly simplified, enabling vaccination programs in developing countries. The National Cancer Institute (NCI) and the Agencia Costarricense de Investigaciones Biomédicas (ACIB) are conducting, with support from the Bill & Melinda Gates Foundation and the International Agency for Research on Cancer (IARC), a large 24,000 girl study to evaluate the efficacy of a 1-dose regimen. The first component of the study is a four-year non-inferiority trial comparing 1- to 2-dose regimens of the two licensed vaccines. The second component is an observational study that estimates the vaccine efficacy (VE) of each regimen by comparing the HPV infection rates in the trial arms to those in a contemporaneous survey group of unvaccinated girls. In this paper, we describe the design and statistical analysis for this study. We explain the advantage of defining non-inferiority on the absolute risk scale when the expected event rate is near 0 and, given this definition, suggest an approach to account for missing clinic visits. We then describe the problem of estimating VE in the absence of a randomized placebo arm and offer our solution. Copyright © 2018. Published by Elsevier Inc.

  11. Superficial dose evaluation of four dose calculation algorithms

    Science.gov (United States)

    Cao, Ying; Yang, Xiaoyu; Yang, Zhen; Qiu, Xiaoping; Lv, Zhiping; Lei, Mingjun; Liu, Gui; Zhang, Zijian; Hu, Yongmei

    2017-08-01

    Accurate superficial dose calculation is of major importance because of the skin toxicity in radiotherapy, especially within the initial 2 mm depth being considered more clinically relevant. The aim of this study is to evaluate superficial dose calculation accuracy of four commonly used algorithms in commercially available treatment planning systems (TPS) by Monte Carlo (MC) simulation and film measurements. The superficial dose in a simple geometrical phantom with size of 30 cm×30 cm×30 cm was calculated by PBC (Pencil Beam Convolution), AAA (Analytical Anisotropic Algorithm), AXB (Acuros XB) in Eclipse system and CCC (Collapsed Cone Convolution) in Raystation system under the conditions of source to surface distance (SSD) of 100 cm and field size (FS) of 10×10 cm2. EGSnrc (BEAMnrc/DOSXYZnrc) program was performed to simulate the central axis dose distribution of Varian Trilogy accelerator, combined with measurements of superficial dose distribution by an extrapolation method of multilayer radiochromic films, to estimate the dose calculation accuracy of four algorithms in the superficial region which was recommended in detail by the ICRU (International Commission on Radiation Units and Measurement) and the ICRP (International Commission on Radiological Protection). In superficial region, good agreement was achieved between MC simulation and film extrapolation method, with the mean differences less than 1%, 2% and 5% for 0°, 30° and 60°, respectively. The relative skin dose errors were 0.84%, 1.88% and 3.90%; the mean dose discrepancies (0°, 30° and 60°) between each of four algorithms and MC simulation were (2.41±1.55%, 3.11±2.40%, and 1.53±1.05%), (3.09±3.00%, 3.10±3.01%, and 3.77±3.59%), (3.16±1.50%, 8.70±2.84%, and 18.20±4.10%) and (14.45±4.66%, 10.74±4.54%, and 3.34±3.26%) for AXB, CCC, AAA and PBC respectively. Monte Carlo simulation verified the feasibility of the superficial dose measurements by multilayer Gafchromic films. And the rank

  12. Low dose epidemiologic studies

    International Nuclear Information System (INIS)

    Anon.

    1990-01-01

    In this chapter the BEIR committee has reviewed low-dose irradiation studies since the BEIR III report. They have considered the carcinogenic effectiveness of low-LET in populations exposed to radiation from a number of different sources: diagnostic radiography; fallout from nuclear weapons testing; nuclear installations; radiation in the workplace and high levels of natural background radiation

  13. Dose gradient curve: A new tool for evaluating dose gradient.

    Science.gov (United States)

    Sung, KiHoon; Choi, Young Eun

    2018-01-01

    Stereotactic radiotherapy, which delivers an ablative high radiation dose to a target volume for maximum local tumor control, requires a rapid dose fall-off outside the target volume to prevent extensive damage to nearby normal tissue. Currently, there is no tool to comprehensively evaluate the dose gradient near the target volume. We propose the dose gradient curve (DGC) as a new tool to evaluate the quality of a treatment plan with respect to the dose fall-off characteristics. The average distance between two isodose surfaces was represented by the dose gradient index (DGI) estimated by a simple equation using the volume and surface area of isodose levels. The surface area was calculated by mesh generation and surface triangulation. The DGC was defined as a plot of the DGI of each dose interval as a function of the dose. Two types of DGCs, differential and cumulative, were generated. The performance of the DGC was evaluated using stereotactic radiosurgery plans for virtual targets. Over the range of dose distributions, the dose gradient of each dose interval was well-characterized by the DGC in an easily understandable graph format. Significant changes in the DGC were observed reflecting the differences in planning situations and various prescription doses. The DGC is a rational method for visualizing the dose gradient as the average distance between two isodose surfaces; the shorter the distance, the steeper the dose gradient. By combining the DGC with the dose-volume histogram (DVH) in a single plot, the DGC can be utilized to evaluate not only the dose gradient but also the target coverage in routine clinical practice.

  14. Regulatory Forum Opinion Piece*: Retrospective Evaluation of Doses in the 26-week Tg.rasH2 Mice Carcinogenicity Studies: Recommendation to Eliminate High Doses at Maximum Tolerated Dose in Future Studies. A Response to the Counterpoints.

    Science.gov (United States)

    Paranjpe, Madhav G; Denton, Melissa D; Vidmar, Tom J; Elbekai, Reem H

    2016-01-01

    We recently conducted a retrospective analysis of data collected from 29 Tg.rasH2 carcinogenicity studies conducted at our facility to determine how successful was the strategy of choosing the high dose of the 26-week studies based on an estimated maximum tolerated dose (MTD). As a result of our publication, 2 counterviews were expressed. Both counterviews illustrate very valid points in their interpretation of our data. In this article, we would like to highlight clarifications based on several points and issues they have raised in their papers, namely, the dose-level selection, determining if MTD was exceeded in 26-week studies, and a discussion on the number of dose groups to be used in the studies. © The Author(s) 2015.

  15. Evaluation of Mangosteen juice blend on biomarkers of inflammation in obese subjects: a pilot, dose finding study

    Directory of Open Access Journals (Sweden)

    Singh Betsy B

    2009-10-01

    Full Text Available Abstract Background The ability to reduce inflammation in overweight and obese individuals may be valuable in preventing the progression to metabolic syndrome with associated risks for heart disease and diabetes. The purpose of this study was to evaluate the effect of multiple dosages of a proprietary Mangosteen Juice blend on indicators of inflammation and antioxidant levels in obese patients with elevated C-reactive protein (CRP levels. Methods The study was an 8 week randomized, double-blind, placebo-controlled study with a pre-study 2 week washout period. The study included four groups including placebo and three difference doses of the test product, XanGo Juice™: 3, 6 or 9 oz twice daily. The primary outcome measure of this study was high-sensitivity (HS-CRP. Secondary outcome measures included other biochemical indicators of inflammation, anthropomorphic measures and a safety evaluation. Results One hundred twenty two (122 persons were screened for the study, 44 were randomized and 40 completed the study. HS-CRP measurements dropped after 8 weeks treatment compared to baseline in all 3 dose groups and increased in the placebo group. The changes from baseline were not significant but the comparison of change from baseline was significant for the 18 oz group when compared to placebo (p = 0.02. Other markers of inflammation (inflammatory cytokines and a marker for lipid peroxidation (F2 isoprostane did not show any significant differences when compared with placebo. There was a trend towards a decrease in BMI in the juice groups. There were no side effects reported in any of the groups and none of the laboratory or EKG safety assessments indicated clinically significant changes for any subject. Conclusion In this pilot, dose-finding study, a proprietary mangosteen juice blend (XanGo Juice™ reduced CRP levels (increased change from baseline compared to placebo for those taking the highest dose of 18 oz per day. Further studies with a

  16. Evaluation of Mangosteen juice blend on biomarkers of inflammation in obese subjects: a pilot, dose finding study.

    Science.gov (United States)

    Udani, Jay K; Singh, Betsy B; Barrett, Marilyn L; Singh, Vijay J

    2009-10-20

    The ability to reduce inflammation in overweight and obese individuals may be valuable in preventing the progression to metabolic syndrome with associated risks for heart disease and diabetes. The purpose of this study was to evaluate the effect of multiple dosages of a proprietary Mangosteen Juice blend on indicators of inflammation and antioxidant levels in obese patients with elevated C-reactive protein (CRP) levels. The study was an 8 week randomized, double-blind, placebo-controlled study with a pre-study 2 week washout period. The study included four groups including placebo and three difference doses of the test product, XanGo Juice: 3, 6 or 9 oz twice daily. The primary outcome measure of this study was high-sensitivity (HS)-CRP. Secondary outcome measures included other biochemical indicators of inflammation, anthropomorphic measures and a safety evaluation. One hundred twenty two (122) persons were screened for the study, 44 were randomized and 40 completed the study. HS-CRP measurements dropped after 8 weeks treatment compared to baseline in all 3 dose groups and increased in the placebo group. The changes from baseline were not significant but the comparison of change from baseline was significant for the 18 oz group when compared to placebo (p = 0.02). Other markers of inflammation (inflammatory cytokines) and a marker for lipid peroxidation (F2 isoprostane) did not show any significant differences when compared with placebo. There was a trend towards a decrease in BMI in the juice groups. There were no side effects reported in any of the groups and none of the laboratory or EKG safety assessments indicated clinically significant changes for any subject. In this pilot, dose-finding study, a proprietary mangosteen juice blend (XanGo Juice) reduced CRP levels (increased change from baseline) compared to placebo for those taking the highest dose of 18 oz per day. Further studies with a larger population are required to confirm and further define the

  17. Evaluation of X ray radiation doses in pediatric examinations of cranial computerized tomography based on optimization studies

    International Nuclear Information System (INIS)

    Daros, Kellen Adriana Curci

    2005-01-01

    This paper identifies the technical conditions for CT examination which offers lowest absorbed dose and to attend the manufacturer recommendations as far the spatial resolution is concerned. The paper evaluates the absorbed dose during cranial CT in up to 6 years children satisfying the technical condition recommended by the manufacturer and routine clinical conditions. The paper also established a quantitative relationship among the absorbed dose and its distribution in the cranial regions of pediatric patients up to 6 years old in a way to estimate the doses subject to optimized conditions

  18. Dose-ranging evaluation of intravitreal siRNA PF-04523655 for diabetic macular edema (the DEGAS study)

    DEFF Research Database (Denmark)

    Nguyen, Quan Dong; Schachar, Ronald A; Nduaka, Chudy I

    2012-01-01

    To evaluate the safety and efficacy of three doses of PF-04523655, a 19-nucleotide methylated double stranded siRNA targeting the RTP801 gene, for the treatment of diabetic macular edema (DME) compared to focal/grid laser photocoagulation.......To evaluate the safety and efficacy of three doses of PF-04523655, a 19-nucleotide methylated double stranded siRNA targeting the RTP801 gene, for the treatment of diabetic macular edema (DME) compared to focal/grid laser photocoagulation....

  19. Experimental evaluation of neutron dose in radiotherapy patients: Which dose?

    Energy Technology Data Exchange (ETDEWEB)

    Romero-Expósito, M., E-mail: mariateresa.romero@uab.cat; Domingo, C.; Ortega-Gelabert, O.; Gallego, S. [Grup de Recerca en Radiacions Ionizants (GRRI), Departament de Física, Universitat Autònoma de Barcelona, Bellaterra 08193 (Spain); Sánchez-Doblado, F. [Departamento de Fisiología Médica y Biofísica, Universidad de Sevilla, Sevilla 41009 (Spain); Servicio de Radiofísica, Hospital Universitario Virgen Macarena, Sevilla 41009 (Spain)

    2016-01-15

    Purpose: The evaluation of peripheral dose has become a relevant issue recently, in particular, the contribution of secondary neutrons. However, after the revision of the Recommendations of the International Commission on Radiological Protection, there has been a lack of experimental procedure for its evaluation. Specifically, the problem comes from the replacement of organ dose equivalent by the organ-equivalent dose, being the latter “immeasurable” by definition. Therefore, dose equivalent has to be still used although it needs the calculation of the radiation quality factor Q, which depends on the unrestricted linear energy transfer, for the specific neutron irradiation conditions. On the other hand, equivalent dose is computed through the radiation weighting factor w{sub R}, which can be easily calculated using the continuous function provided by the recommendations. The aim of the paper is to compare the dose equivalent evaluated following the definition, that is, using Q, with the values obtained by replacing the quality factor with w{sub R}. Methods: Dose equivalents were estimated in selected points inside a phantom. Two types of medical environments were chosen for the irradiations: a photon- and a proton-therapy facility. For the estimation of dose equivalent, a poly-allyl-diglicol-carbonate-based neutron dosimeter was used for neutron fluence measurements and, additionally, Monte Carlo simulations were performed to obtain the energy spectrum of the fluence in each point. Results: The main contribution to dose equivalent comes from neutrons with energy higher than 0.1 MeV, even when they represent the smallest contribution in fluence. For this range of energy, the radiation quality factor and the radiation weighting factor are approximately equal. Then, dose equivalents evaluated using both factors are compatible, with differences below 12%. Conclusions: Quality factor can be replaced by the radiation weighting factor in the evaluation of dose

  20. [Evaluation of patient doses in interventional radiology].

    Science.gov (United States)

    Ropolo, R; Rampado, O; Isoardi, P; Gandini, G; Rabbia, C; Righi, D

    2001-01-01

    To verify the suitability of indicative quantities to evaluate the risk related to patient exposure, in abdominal and vascular interventional radiology, by the study of correlations between dosimetric quantities and other indicators. We performed in vivo measurements of entrance skin dose (ESD) and dose area product (DAP) during 48 procedures to evaluate the correlation among dosimetric quantities, and an estimation of spatial distribution of exposure and effective dose (E). To measure DAP we used a transmission ionization chamber and to evaluate ESD and its spatial distribution we used radiographic film packed in a single envelope and placed near the patient's skin. E was estimated by a calculation software using data from film digitalisation. From the data derived for measurements in 27 interventional procedures on 48 patients we obtained a DAP to E conversion factor of 0.15 mSv / Gy cm2, with an excellent correlation (r=.99). We also found a good correlation between DAP and exposure parameters such as fluoroscopy time and number of images. The greatest effective dose was evaluated for a multiple procedure in the hepatic region, with a DAP value of 425 Gy cm2. The greatest ESD was about 550 mGy. For groups of patients undergoing similar interventional procedures the correlation between ESD and DAP had conversion factors from 6 to 12 mGy Gy-1 cm-2. The evaluation of ESD and E by slow films represents a valid method for patient dosimetry in interventional radiology. The good correlation between DAP and fluoroscopy time and number of images confirm the suitability of these indicators as basic dosimetric information. All the ESD values found are lower than threshold doses for deterministic effects.

  1. An observational study evaluating tacrolimus dose, exposure, and medication adherence after conversion from twice- to once-daily tacrolimus in liver and kidney transplant recipients.

    Science.gov (United States)

    Bäckman, Lars; Persson, Carl-Axel

    2014-03-17

    Immunosuppression regimens in transplantation medicine are complex. Drugs with extended release action have simplified medication dosing without affecting efficacy. This prospective, observational, multicenter study, conducted in a routine medical practice setting, evaluated changes in tacrolimus daily dose and trough levels and patient-reported medication adherence at day 90 after 1:1 (mg: mg) conversion to once-daily tacrolimus in adult liver and kidney transplant recipients. Data from 224 recipients of a liver (n=19) or kidney (n=205) transplant, average age 51±14.5 years, were evaluated. The mean change in tacrolimus daily dose was +0.04 mg/day. Dose remained stable after conversion in 62.5%, was lower in 15.6%, and higher in 22% of patients. Trough level after conversion was lower in 62.6% and higher in 36.5%; generally, levels were 12.8% lower than pre-conversion levels. No acute rejection, graft loss, or serious safety events were observed. Two deaths occurred due to myocardial infarction. Conversion helped 19% to less frequently forget medications and 55% reported no difference in remembering to take the once-daily dose after conversion. The change in dosing frequency was identified as "better" for 55%. Tacrolimus daily dose remained stable while trough levels were significantly lower after conversion to once-daily dosing. Safety and efficacy were maintained; reduced dosing frequency had no apparent influence on patient-reported medication adherence.

  2. Dose-to-man studies

    International Nuclear Information System (INIS)

    Anon.

    1976-01-01

    Dose-to-Man Studies focused on developing computer data handling and computer modules which permit easy, rapid assessment of the dose to southeastern United States populations from routine or accidental releases of radionuclides to atmospheric and stream systems

  3. A dose-finding, cross-over study to evaluate the effect of a Nestorone®/Estradiol transdermal gel delivery on ovulation suppression in normal ovulating women.

    Science.gov (United States)

    Brache, Vivian; Merkatz, Ruth; Kumar, Narender; Jesam, Cristian; Sussman, Heather; Hoskin, Elena; Roberts, Kevin; Alami, Mohcine; Taylor, Deshawn; Jorge, Aidelis; Croxatto, Horacio; Lorange, Ellen; Mishell, Daniel R; Sitruk-Ware, Regine

    2015-10-01

    This study aims to determine the lowest effective of three Nestorone (NES)/estradiol (E2) transdermal gel doses to ensure ovulation suppression in 90-95% of cycles. This was a randomized, open-label, three-treatment-period cross-over study to evaluate the effects of NES/E2 transdermal gel on ovulation inhibition, suppression of follicular growth and pharmacokinetic parameters. The doses were low (1.5 mg NES/0.5 mg E2), medium (3.0 mg NES/1.0 mg E2) and high (4.5 mg NES/1.5 mg E2). Participants applied gel daily to a fixed area on the abdomen for 21 consecutive days. They were interviewed regarding their experiences using the gel. Eighteen participants were randomized; 16 completed the study. Median NES C(max) values for low, medium and high dose groups at day 21 were 318.6 pmol/L, 783.0 pmol/L and 1063.8 pmol/L, respectively. Median maximum follicular diameter was higher with the lowest dose with 16.2 mm versus 10.0 and 10.4 mm with the medium and high doses, respectively. Among adherent participants, ovulation was inhibited in all dose groups, except for one participant in the medium dose (6.7%) that had luteal activity and an ultrasound image suggestive of a luteinized unruptured follicle. There were few reports of unscheduled bleeding, with more episodes reported for the lower dose. Adverse events were mild, and no skin irritation was reported from gel application. While all three doses blocked ovulation effectively and were evaluated as safe and acceptable, the medium dose was considered the lowest effective dose based on a more adequate suppression of follicular development. Further development of this novel contraceptive delivering NES and E2 is warranted and has potential for improved safety compared to ethinyl-estradiol-based methods. Copyright © 2015 Elsevier Inc. All rights reserved.

  4. Evaluation of occupational and patient radiation doses in orthopedic surgery

    International Nuclear Information System (INIS)

    Sulieman, A.; Alzimami, K.; Habeeballa, B.; Osman, H.; Abdelaziz, I.; Sassi, S.A.; Sam, A.K.

    2015-01-01

    This study intends to measure the radiation dose to patients and staff during (i) Dynamic Hip Screw (DHS) and (ii) Dynamic Cannula Screw (DCS) and to evaluate entrance surface Air kerma (ESAK) dose and organ doses and effective doses. Calibrated Thermoluminescence dosimeters (TLD-GR200A) were used. The mean patients’ doses were 0.46 mGy and 0.07 mGy for DHS and DCS procedures, respectively. The mean staff doses at the thyroid and chest were 4.69 mGy and 1.21 mGy per procedure. The mean organ and effective dose for patients and staff were higher in DHS compared to DCS. Orthopedic surgeons were exposed to unnecessary radiation doses due to the lack of protection measures. The radiation dose per hip procedure is within the safety limit and less than the previous studies

  5. Multicenter study on evaluation of the entrance skin dose by a direct measurement method in cardiac interventional procedures

    International Nuclear Information System (INIS)

    Kato, Mamoru; Chida, Koichi; Moritake, Takashi

    2016-01-01

    Deterministic effects have been reported in cardiac interventional procedures. To prevent radiation skin injuries in percutaneous coronary intervention (PCI), it is necessary to measure accurate patient entrance skin dose (ESD) and maximum skin absorbed dose (MSD). We measured the MSD on 62 patients in four facilities by using the Chest-RADIREC system. The correlation between MSD and fluoroscopic time, dose area product (DAP), and cumulative air kerma (AK) showed good results, with the correlation between MSD and AK being the strongest. The regression lines using MSD as an outcome value (y) and AK as predictor variables (x) was y=1.18x (R 2 =0.787). From the linear regression equation, MSD is estimated to be about 1.18 times that of AK in real time. The Japan diagnostic reference levels (DRLs) 2015 for IVR was established by the use of dose rates using acrylic plates (20 cm thick) at the interventional reference point. Preliminary reference levels proposed by International Atomic Energy Agency (IAEA) were provided using DAP. In this study, AK showed good correlation most of all. Hence we think that Japanese DRLs for IVR should reconsider by clinical patients' exposure dose such as AK. (author)

  6. Intracavitary radiation treatment planning and dose evaluation

    International Nuclear Information System (INIS)

    Anderson, L.L.; Masterson, M.E.; Nori, D.

    1987-01-01

    Intracavitary radiation therapy with encapsulated radionuclide sources has generally involved, since the advent of afterloading techniques, inserting the sources in tubing previously positioned within a body cavity near the region to be treated. Because of the constraints on source locations relative to the target region, the functions of treatment planning and dose evaluation, usually clearly separable in interstitial brachytherapy, tend to merge in intracavitary therapy. Dose evaluation is typically performed for multiple source-strength configurations in the process of planning and thus may be regarded as complete when a particular configuration has been selected. The input data for each dose evaluation, of course, must include reliable dose distribution information for the source-applicator combinations used. Ultimately, the goal is to discover the source-strength configuration that results in the closest possible approach to the dose distribution desired

  7. Manual of dose evaluation from atmospheric releases

    Energy Technology Data Exchange (ETDEWEB)

    Shirvaikar, V V; Abrol, V [Health Physics Division, Bhabha Atomic Research Centre, Bombay (India)

    1978-07-01

    The problem of dose evaluation from atmospheric releases is reduced to simple arithmetic by giving tables of concentrations and time integrated concentrations for instantaneous plumes and long time (1 year), sector averaged plumes for distances upto 10 km, effective release heights of upto 200 m and the six Pasquill stability classes. Correction factors for decay, depletion due to deposition and rainout are also given. Inhalation doses, immersion doses and contamination levels can be obtained from these by using multiplicative factors tabulated for various isotopes of significance. Tables of external gamma doses from plume are given separately for various gamma energies. Tables are also given to evaluate external beta and gamma dose rates from contaminated surfaces. The manual also discusses the basic diffusion model relevant to the problem. (author)

  8. Evaluation of absorbed dose in studies of renal function due to 123I/131I (hippuran) e 111In (DPTA)

    International Nuclear Information System (INIS)

    Vasquez, M.V.; Castillo, C.E.; Rojas, R.; Cabrera, C.; Abanto, D.; Morgan, A.; Diaz, E.E.

    2015-01-01

    The absorbed dose of the kidneys during renal function studies of adult patients is estimated through biokinetics of radiopharmaceuticals containing the 123 I/ 131 I (hippuran) e 111 In (DPTA). Using the methodology MIRD and representation Cristy-Eckerman for adult kidneys, it is shown that dosimetric contributions of organs of biokinetics 123 I/ 131 I (hippuran) e 111 In (DPTA) are significant, in estimative of dose for renal function studies. Dosimetric contributions (body and whole bladder, kidneys excluding) are given by 11.90% (for 123 I), 4.97% (for 131 I) and 28.32% (for 111 In). In all cases, the dosimetric contributions are mainly due to photons issued by the whole body

  9. Developing guidelines for economic evaluation of environmental impacts in EIAs. Part II: Case studies and dose-response literature

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-07-01

    This Part II of the report contains full versions of the case studies for air, water and land (Chapters 2-4), which were only summarised in Part I. In addition, during the work the research team has collected a large amount of literature and information on dose response relationships for air and water pollution relevant to China. This information is included as Chapters 5 and 6.

  10. Developing guidelines for economic evaluation of environmental impacts in EIAs. Part II: Case studies and dose-response literature

    International Nuclear Information System (INIS)

    2005-01-01

    This Part II of the report contains full versions of the case studies for air, water and land (Chapters 2-4), which were only summarised in Part I. In addition, during the work the research team has collected a large amount of literature and information on dose response relationships for air and water pollution relevant to China. This information is included as Chapters 5 and 6

  11. Prospective study evaluating the radiosensitizing effect of reduced doses of temozolomide in the treatment of Egyptian patients with glioblastoma multiforme

    Directory of Open Access Journals (Sweden)

    Gaber M

    2013-10-01

    Full Text Available May Gaber, Hanan Selim, Tamer El-NahasDepartment of Clinical Oncology, Cairo University, Cairo, EgyptPurpose: In view of the documented toxicity of continuous daily radiosensitizer doses of temozolomide concomitant with radiation in the treatment of glioblastoma multiforme, we aimed to compare it with a different schedule of abbreviated radiosensitizer dosing.Patients and methods: This was a randomized prospective study comparing toxicity and survival in 60 Egyptian patients with glioblastoma multiforme. Patients in arm I received temozolomide at a dose of 75 mg/m2 daily with radiotherapy for 42 days, starting 4 weeks after surgery and reaching to a total radiation dose of 60 Gy/30 Fractions/6 weeks, while patients in arm II received temozolomide at a dose of 75 mg/m2 concomitantly with the same radiotherapy schedule daily in the first and last weeks of the same radiotherapy program.Results: Common grade 1–2 adverse events were malaise in 28 patients (46.7%, followed by alopecia (40% and nausea (26.7%. Grade 3–4 convulsion and decreased level of consciousness was seen in only four patients who were all from arm I. The median progression-free survival (PFS for the entire study population was 10.6 months (95% confidence interval [CI] 7.3–14, and PFS at 12 months was 32%. The median PFS in arm I was 8.8 months (95% CI 5.9–11.7 and in arm II 11.5 months (95% CI 8.9–14.2, and PFS at 12 months for both arms was 32% and 30% respectively (P=0.571. The median overall survival (OS of the whole group of patients was 14.2 months (95% CI 13–15.5, and OS was 70% at 12 months and 25% at 18 months. The median OS for patients in arm I was 12.3 months (95% CI 7.7–16.9, whereas in arm II it was 14.3 months (95% CI 14–14.7 (P=0.83.Conclusion: Reduced radiosensitizer dosing of temozolomide concomitant with radiotherapy in glioblastoma multiforme exhibited comparable efficacy with a classic continuous daily schedule, though with better tolerability

  12. Evaluation of patient dose during computed tomography angiography

    International Nuclear Information System (INIS)

    Dafalla, Elamam Yagoob Taha

    2015-10-01

    Computed tomography (CT), is an x-ray procedure that generates high quality cross sectional images of the body, and by comparison to other radiological diagnosis, CT is responsible for higher doses to patients. The evaluation of patient dose from computed tomography for pulmonary examinations the CT is responsible for higher doses to patients. The radiation dose was measured in three hospitals in Khartoum State during March 2015-October 2015 using different CT modalities. The radiation dose was higher at Alzytouna hospital than Daralelaj hospital and Alatebaa hospital was lowest. In this study, the mean effective dose for first hospital was 23.83±3.93 mSv and the mean effective dose for second hospital was 8.94±1.64 mSv and the mean effective dose for third hospital was 2.96±0.79. (author)

  13. Evaluations of gonad and fetal doses for diagnostic radiology.

    Science.gov (United States)

    Tung, C J; Tsai, H Y

    1999-07-01

    A national survey of patient doses for diagnostic radiology was planned in the Republic of China. We performed a pilot study for this survey to develop a protocol of the dose assessments. Entrance skin doses and organ (including ovary, testicle and uterus) doses were measured by thermoluminescent dosimeters and calculated by means of Monte Carlo simulations for several diagnostic procedures. We derived a formula and used the RadComp software for the computation of entrance skin doses. This formula involves several factors, such as kVp, mAs, the focus-to-skin-distance and aluminum filtration. RadComp software was applied to obtain free-air entrance exposures which were converted to entrance skin doses by considering the backscattering radiation from the body. Organ doses were measured using a RANDO phantom and calculated using a mathematical phantom for several diagnostic examinations. Genetically significant doses were calculated from ovary and testicle doses for the evaluation of hereditary effects. Embryo/fetal doses were determined from the uterine doses by considering the increase in uterus size with gestational age. We found that the patient doses studied in this work were all below the reference doses recommended by the National Radiological Protection Board of the U.K.

  14. Study on dose calculation method for operational intervention Level. Evaluation of the intake of foods and drinks for OIL6

    International Nuclear Information System (INIS)

    Yoshida, Yoshitaka; Takahashi, Shunsuke

    2017-01-01

    In the guideline for nuclear disaster countermeasures, the operational intervention level (OIL) is an index for decision making of protective measures to be applied in an urgent protective action planning zone (UPZ) and in the zone immediately outside it, for the period starting several hours after a general emergency is declared to within a week after this. In this guideline, the initialization value of OIL6 is set as the protective measure index for intake of foods and drinks. OIL is observed by using actual measurement values in a nuclear emergency, and OIL6 is the measured activity concentration of radioactive materials (Bq/kg) in foods and drinks. On the other hand, the IAEA sets the generic criteria for protective measures from the viewpoint of the radiation effects to the human body. Therefore, it has been necessary to prepare an expression for the OIL6 dose and a dose conversion factor in order to confirm whether the dose does not exceed the generic criteria from the annual intake data of foods and drinks in Japan when contaminated foods and drinks are consumed continuously for 1 year. In this work, we examined the problem about the uncertainty of the annual intake data of foods and drinks. We took the annual intake data of foods and drinks for OIL6 based on the national health and nutrition survey results by the Ministry of Health, Labor and Welfare and we calculated a OIL6 dose when foods and drinks were contaminated at the same level as the initialization value of the restricted consumption of foods and drinks, taking into account the influences for age, gender and local area. As a result, we found the 95% upper limit value of the intake data of foods and drinks for OIL6 obtained by this study could be used. The OIL6 intake data of foods and drinks prepared by previous studies were underestimating vegetables and cereals, etc. The OIL6 dose was sufficiently below IAEA generic criteria, and the intake data of foods and drinks between the local areas had no

  15. Impact of catheter reconstruction error on dose distribution in high dose rate intracavitary brachytherapy and evaluation of OAR doses

    International Nuclear Information System (INIS)

    Thaper, Deepak; Shukla, Arvind; Rathore, Narendra; Oinam, Arun S.

    2016-01-01

    In high dose rate brachytherapy (HDR-B), current catheter reconstruction protocols are relatively slow and error prone. The purpose of this study is to evaluate the impact of catheter reconstruction error on dose distribution in CT based intracavitary brachytherapy planning and evaluation of its effect on organ at risk (OAR) like bladder, rectum and sigmoid and target volume High risk clinical target volume (HR-CTV)

  16. Dose evaluation of narrow-beam

    International Nuclear Information System (INIS)

    Goto, Shinichi

    1999-01-01

    Reliability of the dose from the narrow photon beam becomes more important since the single high-dose rate radiosurgery becoming popular. The dose evaluation for the optimal dose is difficult due to absence of lateral electronic equilibrium. Data necessary for treatment regimen are TMR (tissue maximum ratio), OCR (off center ratio) and S c,p (total scatter factor). The narrow-beam was 10 MV X-ray from Varian Clinac 2100C equipped with cylindrical Fischer collimator CBI system. Detection was performed by Kodak XV-2 film, a PTW natural diamond detector M60003, Scanditronics silicon detector EDD-5 or Fujitec micro-chamber FDC-9.4C. Phantoms were the water equivalent one (PTW, RW3), water one (PTW, MP3 system) and Wellhofer WP600 system. Factors above were actually measured to reveal that in the dose evaluation of narrow photon beam, TMR should be measured by micro-chamber, OCR, by film, and S c,p , by the two. The use of diamond detector was recommended for more precise measurement and evaluation of the dose. The importance of water phantom in the radiosurgery system was also shown. (K.H.)

  17. Open-Label Single-Sequence Crossover Study Evaluating Pharmacokinetics, Efficacy, and Safety of Once-Daily Dosing of Nitisinone in Patients with Hereditary Tyrosinemia Type 1.

    Science.gov (United States)

    Guffon, Nathalie; Bröijersén, Anders; Palmgren, Ingrid; Rudebeck, Mattias; Olsson, Birgitta

    2018-01-01

    Although nitisinone is successfully used to treat hereditary tyrosinemia type 1 (HT-1) with the recommended twice-daily dosing, data describing a long half-life motivate less frequent dosing. Therefore, in agreement with the Pharmacovigilance Risk Assessment Committee at the European Medicines Agency, this study was performed to investigate the switch to once-daily dosing. This open-label, non-randomized, single-sequence crossover study evaluated the pharmacokinetics, efficacy, and safety of once-daily compared to twice-daily dosing of nitisinone in patients with HT-1 (NCT02323529). Well-controlled patients of dry blood spots by tandem mass spectrometry. The primary endpoint was C min of nitisinone after ≥4 weeks of treatment on each dosing regimen. Secondary objectives were evaluation of efficacy and safety during each dosing regimen. In total, 19 patients were enrolled and 17 included in the per-protocol analysis set. The mean (SD) nitisinone C min decreased by 23%, from 26.4 (10.2) to 21.2 (9.9) μmol/L in dry blood spot samples (not equivalent to plasma concentrations), when patients switched from twice- to once-daily dosing. There was no apparent age- or bodyweight-related trend in the degree of C min decrease. No patient had quantifiable succinylacetone levels during the once-daily treatment period, indicating efficacious treatment. All adverse events were mild or moderate and judged unrelated to nitisinone. The switch to once-daily treatment with nitisinone appeared efficacious and safe in the treatment of patients with HT-1.

  18. Evaluation of Patient Radiation Dose during Orthopedic Surgery

    International Nuclear Information System (INIS)

    Osman, H; Elzaki, A.; Sam, A.K.; Sulieman, A.

    2013-01-01

    The number of orthopedic procedures requiring the use of the fluoroscopic guidance has increased over the recent years. Consequently the patient exposed to un avoidable radiation doses. The aim of the current study was to evaluate patient radiation dose during these procedures.37 patients under went dynamic hip screw (DHS) and dynamic cannulated screw (DCS) were evaluated using calibrated Thermolumincent Dosimeters (TLDs), under carm fluoroscopic machines ,in three centers in Khartoum-Sudan. The mean Entrance Skin Dose (ESD) was 7.9 m Gy per procedure. The bone marrow and gonad organ exposed to significant doses. No correlation was found between ESD and Body Mass Index (BMI), or patient weight. Well correlation was found between kilo voltage applied and ESD. Orthopedic surgeries delivered lower radiation dose to patients than cardiac catheterization or hysterosalpingraphy (HSG) procedures. More study should be implemented to follow radiation dose before surgery and after surgery

  19. Evaluation of radiation doses from radioactive drugs

    International Nuclear Information System (INIS)

    Halperin, J.A.; Grove, G.R.

    1977-01-01

    Radioactive new drugs are regulated by the Food and Drug Administration (FDA) in the United States. Before a new drug can be marketed it must have an approved New Drug Application (NDA). Clinical investigations of a radioactive new drug are carried out under a Notice of Claimed Investigational Exemption for a New Drug (IND), submitted to the FDA. In the review of the IND, radiation doses are projected on the basis of experimental data from animal models and from calculations based upon radiation characteristics, predicted biodistribution of the drug in humans, and activity to be administered. FDA physicians review anticipated doses and prevent clinical investigations in humans when the potential risk of the use of a radioactive substance outweighs the prospect of achieving beneficial results from the administration of the drug. In the evaluation of an NDA, FDA staff attempt to assure that the intended diagnostic or therapeutic effect is achievable with the lowest practicable radiation dose. Radiation doses from radioactive new drugs are evaluated by physicians within the FDA. Important radioactive new drugs are also evaluated by the Radiopharmaceuticals Advisory Committee. FDA also supports the Center for Internal Radiation Dosimetry at Oak Ridge, to provide information regarding in vivo distribution and dosimetry to critical organs and the whole body from radioactive new drugs. The process for evaluation of radiation doses from radioactive new drugs for protection against use of unnecessary radiation exposure by patients in nuclear medicine procedures, a

  20. Evaluation of the dose uniformity for double-plane high dose rate interstitial breast implants with the use of dose reference points and dose non-uniformity ratio

    International Nuclear Information System (INIS)

    MAjor, T.; Polgar, C.; Somogyi, A.; Nemeth, G.

    2000-01-01

    This study investigated the influence of dwell time optimizations on dose uniformity characterized by dose values in dose points and dose non-uniformity ratio (DNR) and analyzed which implant parameters have influence on the DNR. Double-plane breast implants with catheters arranged in triangular pattern were used for the calculations. At a typical breast implant, dose values in dose reference points inside the target volume and volumes enclosed by given isodose surfaces were calculated and compared for non-optimized and optimized implants. The same 6-cm treatment length was used for the comparisons. Using different optimizations plots of dose non-uniformity ratio as a function of catheter separation, source step size, number of catheters, length of active sections were drawn and the minimum DNR values were determined. Optimization resulted in less variation in dose values over dose points through the whole volume and in the central plane only compared to the non-optimized case. At implant configurations consisting of seven catheters with 15-mm separation, 5-mm source step size and various active lengths adapted according to the type of optimization, the no optimization, geometrical (volume mode) and dose point (on dose points and geometry) optimization resulted in similar treatment volumes, but an increased high dose volume was observed due to the optimization. The dose non-uniformity ratio always had the minimum at average dose over dose normalization points, defined in the midpoints between the catheters through the implant volume. The minimum value of DNR depended on catheter separation, source step size, active length and number of catheters. The optimization had only a small influence on DNR. In addition to the reference points in the central plane only, dose points positioned in the whole implant volume can be used for evaluating the dose uniformity of interstitial implants. The dose optimization increases not only the dose uniformity within the implant but

  1. Image quality evaluation and patient dose assessment of medical fluoroscopic X-ray systems: A national study

    International Nuclear Information System (INIS)

    Economides, S.; Hourdakis, C. J.; Kalivas, N.; Kalathaki, M.; Simantirakis, G.; Tritakis, P.; Manousaridis, G.; Vogiatzi, S.; Kipouros, P.; Boziari, A.; Kamenopoulou, V.

    2008-01-01

    This study presents the results from a survey conducted by the Greek Atomic Energy Commission (GAEC), during the period 1998-2003, in 530 public and private owned fluoroscopic X-ray systems in Greece. Certain operational parameters for conventional and remote control systems were assessed, according to a quality control protocol developed by GAEC on the basis of the current literature. Public (91.5%) and private (81.5%) owned fluoroscopic units exhibit high-contrast resolution values over 1 lp mm -1 . Moreover, 88.5 and 87.1% of the fluoroscopic units installed in the public and private sector, respectively, present Maximum Patient Entrance Kerma Rate values lower than 100 mGy min -1 . Additionally, 68.3% of the units assessed were found to perform within the acceptance limits. Finally, the third quartile of the Entrance Surface Dose Rate distribution was estimated according to the Dose Reference Level definition and found equal to 35 mGy min -1 . (authors)

  2. Some aspects of dose evaluation, 3

    International Nuclear Information System (INIS)

    Yoshida, Yoshikazu

    1979-01-01

    This paper describes methods of calculating the radioiodine releases and resultant doses in the ''Guide for calculation of doses to man from routine releases of effluents from light-water-cooled nuclear power plants for evaluating compliance with dose objectives around a site of LWRs'' by the Japan Nuclear Safety Commission. Examples of dose calculation in the design stage of plants and releases of radioiodine from operating plants are also given. The thyroid dose objective from radioiodine in reactor effluents was determined to be 15 mrem per year by the AEC of Japan in 1975. In the guide, models and parameters are given as most realistic on the basis of current knowledge and experience; in cases involving unknown factors these are on conservative side. Calculations of annual average releases of gaseous and liquid effluents are made using the models and parameters established through operational experiences of the LWR plants. Annual thyroid doses are calculated from inhalation and ingestion of leafy vegetable and cow's milk for gaseous effluents and ingestion of marine food for liquid effluents. In calculation of the thyroid dose, fw = 0.2 is used instead of = 0.3 in ICRP publ. 2 for ingestion of foods excluding seaweed and the specific activity method for ingestion of foods including seaweed. It is because Japanese take foods with much stable iodine. Calculated annual releases of 131 I in gaseous effluents of typical BWR (1100 MWe) and PWR (800 MWe) are about 2 Ci and 0.7 Ci per year per plant and the annual thyroid doses are about 4 mrem and 9 mrem per year, respectively. Actually, however, releases of 131 I in gaseous effluents from the operating LWR plants are about less than one tenth of the above figures. (author)

  3. Literature study of the radiobiological parameters of Caesium-137 required for evaluating internal irradiation doses as a function of age

    International Nuclear Information System (INIS)

    Garnier, A.

    1968-01-01

    This document reassembles information published in scientific literature on radiobiological parameters of Cs-137, necessary for the estimate of the internal irradiation dose of man according to his age (during growth). The data are completed by a commented review of the mathematical models, proposed in order to value the irradiation doses from ingested cesium and the biological parameters. (author) [fr

  4. Evaluation of worker's dose on a virtual dismantling environment

    International Nuclear Information System (INIS)

    Park, Hee Seong; Kim, Sung Hyun; Park, Byung Suk; Yoon, Ji Sup

    2007-01-01

    The motivation of this study is to provide a basis for a minimization of worker's dose during dismantling activities. In the present study, we proposed methods for identifying an existence of radioactivity which is contained in the dismantling objects and for evaluating a worker's dose under a virtual dismantling environment. To evaluate a worker's external dose, the shape of the exposure room in the KRR 2(Korean Research Reactor TRIGA MARK III) by 3D CAD was created and the radiation dose surrounding the facility by using MCNP- 4C(Monte Carlo N-Particle-4C) was calculated. The radiation field of the exposure room was visualized three dimensionally by using the radiation dose that was obtained by the code

  5. Vancomycin Utilization Evaluation: Are We Dosing Appropriately?

    Directory of Open Access Journals (Sweden)

    Ladan Ayazkhoo

    2015-10-01

    Full Text Available Background: Inappropriate use of vancomycin not only increase health care costs but also contribute to the emergence of resistant organisms. Higher trough serum vancomycin concentrations (>10mg/L has been recommended for avoidance of development of resistance. We aim to compare the administered dose with recommended doses based on guideline-recommended weight-based dosing.Methods: In a cross sectional study, all patients who received vancomycin between July and October 2013, in infectious disease, internal medicine wards and emergency department of a teaching hospital in Tehran, Iran were entered to the study. Indication of vancomycin and necessary data for dose calculation including height and serum creatinine were recorded. Prescribed doses were compared with recommended doses in guidelines and calculated Glomerular filtration rate (GFR for each patient.Results: One hundred and four patients (45 females and 59 males recruited in the study. Our results indicated that, from all administered doses of vancomycin, 64.4% and 88.8% differs significantly (more than 20% based on American Pharmacist Association (AphA vancomycin monograph and guideline-recommended, weight-based vancomycin dosing (for adults, respectively.Conclusion: Underdosing of vancomycin is a major risk factor for developing resistance of gram positive organisms to this glycopeptide. Our results showed that more than half of patients receiving vancomycin are in the risk of low drug levels based on guidelines. So, having a comprehensive plan for the proper use of this drug especially designing effective internal guidelines can prevent emergence of resistance to vancomycin in future.

  6. Evaluation of lens dose in medulloblastoma radiotherapy

    International Nuclear Information System (INIS)

    Oliveira, F.L.; Vilela, E.C.; Sousa, S.A; Lima, F.F. de

    2007-01-01

    The improvement of the applied radiotherapy techniques in the cranial-spinal therapy, which is used in the cases of medulloblastoma, aims the reduction of the risks of future damages in enclosed critical agencies in the irradiation fields. This work aims to evaluate the lens doses due two common techniques used in medulloblastoma radiotherapy. For this, thermoluminescent dosimeters, previously calibrated, were located in an anthropomorphic phantom (ALDERSON - RANDON Laboratory), in the tumor and lens positions. The employed techniques were as following: (1) angled fields technique and (2) half-beam block technique. The phantom was irradiated five times in each technique with two lateral opposed fields in the brain with a total prescribed dose of 1.5 Gy, followed of two posterior spinal fields with the same prescribed dose, using a 6MV accelerator. The results showed that the doses in the first technique were 0.10 +- 0,04 Gy and, in second one, 0.09 +- 0,02 Gy. It was observed that, independent of the employed technique, the lens doses practically are the same. (author)

  7. Evaluation of doses in gastrointestinal fluoroscopy

    International Nuclear Information System (INIS)

    Canevaro, Lucia Viviana

    1995-04-01

    This work aims at the development of a methodology to measure radiation doses to patients and professionals (radiologists) in fluoroscopic gastrointestinal tract examinations. Also, it aims at the assessment of the performance of this type of medical x-ray equipment, from the radiation protection point of view at the Department of Radiology of the Hospital Universitario Clementino Fraga Filho (Universidade Federal de Rio de Janeiro). This work was developed in order to identify the actual status and to set base lines as a reference for a quality control program. The calibration procedures of thermoluminescent dosimeters for radiodiagnosis quality beams are discussed and described here as well as its application in dose measurements, for patients and radiologists. The performance of two types of x-ray equipment (fluorescent screen and image intensifier) usually used to perform this examinations was evaluated through appropriate tests. Radiation protection features are also considered. Dose to radiologists at unprotected regions and to patients at several sample points were measured. A comparison of the measured doses given by both types of equipment was made. After further analysis, the necessity to look for methods that reduce unnecessary doses became evident. The high values obtained in some procedures using fluorescent screen make the use of this type of equipment unacceptable. With these results, we consider that Health Care authorities have the responsibility of replacing all fluorescent screen equipment and of establishing standards, and raising awareness the responsible staff. (author)

  8. SU-F-P-26: Study of Radiation Dose Evaluation for Organs at Risk Using MRI in Intensity Modulated Radiation Therapy for Nasopharyngeal Carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Gong, G; Guo, Y; Yin, Y [Shandong Cancer Hospital and Institute, Jinan, Shandong (China)

    2016-06-15

    Purpose: To study the contour and dosimetric feature of organs at risk (OARs) applying magnetic resonance imaging (MRI) images in intensity modulated radiation therapy (IMRT) of nasopharyngeal carcinoma (NPC) compared to computed tomography (CT) images. Methods: 35 NPC patients was selected into this trail. CT simulation with non-contrast and contrast enhanced scan, MRI simulation with non-contrast and contrast enhanced T1, T2 and diffusion weighted imaging were achieved sequentially. And the OARs were contoured on the CT and MRI images after rigid registration respectively. 9 beams IMRT plan with equal division angle were designed for every patients, and the prescription dose for tumor target was set as 72Gy (2.4Gy/ fration). The boundary display, volume and dose-volume indices of each organ were compared between on MRI and CT images. Results: Compared to CT, MRI showed clearer boundary of brainstem, spinal cord, the deep lobe of Parotid gland and the optical nerve in canal. MRI images increase the volume of lens, optical nerve, while reducing the volume of eye slightly, and the maximum dose of lens, the mean dose of eyes and optical raised in different percentage, while there was no statistical differences were found. The left and right parotid volume on MRI increased by 7.07%, 8.13%, and the mean dose raised by 14.95% (4.01Gy), 18.76% (4.95Gy) with statistical significant difference (p<0.05). The brainstem volume reduced by 9.33% (p<0.05), and the dose of 0.1cm3 volume (D0.1cm3) reduced by mean 8.46% (4.32Gy), and D0.1cm3 of spinal cord increased by 1.5Gy on MRI. Conclusion: It is credible to evaluate the radiation dose of lens, eye and the spinal cord, while it should be necessary to evaluate the dose of brainstem, parotid and the optical nerve applying MRI images sometime, it will be more meaningful for these organs with high risk of radiation injury.

  9. Evaluation of two-dimensional bolus effect of immobilization/support devices on skin doses: A radiochromic EBT film dosimetry study in phantom

    International Nuclear Information System (INIS)

    Chiu-Tsao, Sou-Tung; Chan, Maria F.

    2010-01-01

    Purpose: In this study, the authors have quantified the two-dimensional (2D) perspective of skin dose increase using EBT film dosimetry in phantom in the presence of patient immobilization devices during conventional and IMRT treatments. Methods: For 6 MV conventional photon field, the authors evaluated and quantified the 2D bolus effect on skin doses for six different common patient immobilization/support devices, including carbon fiber grid with Mylar sheet, Orfit carbon fiber base plate, balsa wood board, Styrofoam, perforated AquaPlast sheet, and alpha-cradle. For 6 and 15 MV IMRT fields, a stack of two film layers positioned above a solid phantom was exposed at the air interface or in the presence of a patient alpha-cradle. All the films were scanned and the pixel values were converted to doses based on an established calibration curve. The authors determined the 2D skin dose distributions, isodose curves, and cross-sectional profiles at the surface layers with or without the immobilization/support device. The authors also generated and compared the dose area histograms (DAHs) and dose area products from the 2D skin dose distributions. Results: In contrast with 20% relative dose [(RD) dose relative to d max on central axis] at 0.0153 cm in the film layer for 6 MV 10x10 cm 2 open field, the average RDs at the same depth in the film layer were 71%, 69%, 55%, and 57% for Orfit, balsa wood, Styrofoam, and alpha-cradle, respectively. At the same depth, the RDs were 54% under a strut and 26% between neighboring struts of a carbon fiber grid with Mylar sheet, and between 34% and 56% for stretched perforated AquaPlast sheet. In the presence of the alpha-cradle for the 6 MV (15 MV) IMRT fields, the hot spot doses at the effective measurement depths of 0.0153 and 0.0459 cm were 140% and 150% (83% and 89%), respectively, of the isocenter dose. The enhancement factor was defined as the ratio of a given DAH parameter (minimum dose received in a given area) with and without

  10. Evaluation of the enter surface dose, dose in organ and E effective dose, received by personnel and patients in studies of endoscopic retrograde cholangeopancreatography in the General Hospital of Mexico

    International Nuclear Information System (INIS)

    Reyes, S.; Gama T, G.; Beristain, M.; Espino, H.

    2006-01-01

    The ESD for patient and personal is measured: gastroenterologuist endoscopist G1, A1 Assistant and A2 instrumentist that carried out 22 independent therapeutic procedures of CPRE, in a fluoroscopy equipment Toshiba trademark with tube under the table, operated in automatic exposure mode, CAE to average tensions of 80 kVp. The measurement is carried out with film dosemeters of double emulsion Kodak Type 2 trademark, calibrated in terms of H * for the energy of the 137 Cs, first it is determined the films sensitivity like function of the optical density DO, and second the ESD for the effective energy of the radiation beam (50 keV), in three different points from the dosemeter (C, D and H). The films was placed for the personnel in: right hand, front (eye), thyroid and thorax (under D and out F of the lead apron); in the case of the patient three positions were used: thorax, hepatic region and pelvis. The mean values of the ESD and it standard deviation SD in mGy units are determined by: study, personnel, film position in doctor and patient, dosemeter measurement point. The calculated doses in organ are also determined for the patient in the thorax region, liverwort and pelvis its are agreement with the NRPB SR 262 report. Finally the H E and E for medical personnel and patients are estimated demonstrating that its are not exceeded the annual dose limits for the case of the OEP. In the case of the the OEP have for the D thorax an ESD max = 0.04 mGy that one corresponds an H E = 0.02 and E = 0.01 mSv. (Author)

  11. DOZIM - evaluation dose code for nuclear accident

    International Nuclear Information System (INIS)

    Oprea, I.; Musat, D.; Ionita, I.

    2008-01-01

    During a nuclear accident an environmentally significant fission products release can happen. In that case it is not possible to determine precisely the air fission products concentration and, consequently, the estimated doses will be affected by certain errors. The stringent requirement to cope with a nuclear accident, even minor, imposes creation of a computation method for emergency dosimetric evaluations needed to compare the measurement data to certain reference levels, previously established. These comparisons will allow a qualified option regarding the necessary actions to diminish the accident effects. DOZIM code estimates the soil contamination and the irradiation doses produced either by radioactive plume or by soil contamination. Irradiations either on whole body or on certain organs, as well as internal contamination doses produced by isotope inhalation during radioactive plume crossing are taken into account. The calculus does not consider neither the internal contamination produced by contaminated food consumption, or that produced by radioactive deposits resuspension. The code is recommended for dose computation on the wind direction, at distances from 10 2 to 2 x 10 4 m. The DOZIM code was utilized for three different cases: - In air TRIGA-SSR fuel bundle destruction with different input data for fission products fractions released into the environment; - Chernobyl-like accident doses estimation; - Intervention areas determination for a hypothetical severe accident at Cernavoda Nuclear Power Plant. For the first case input data and results (for a 60 m emission height without iodine retention on active coal filters) are presented. To summarize, the DOZIM code conception allows the dose estimation for any nuclear accident. Fission products inventory, released fractions, emission conditions, atmospherical and geographical parameters are the input data. Dosimetric factors are included in the program. The program is in FORTRAN IV language and was run on

  12. Evaluation of repeated dose micronucleus assays of the liver using N-nitrosopyrrolidine: a report of the collaborative study by CSGMT/JEMS.MMS.

    Science.gov (United States)

    Ogawa, Izumi; Hagioa, Soichiro; Furukawa, Satoshi; Abe, Masayoshi; Kuroda, Yusuke; Hayashi, Seigo; Wako, Yumi; Kawasako, Kazufumi

    2015-03-01

    The repeated dose liver micronucleus (RDLMN) assay has the potential to detect liver carcinogens, and can be integrated into a general toxicological study. To assess the performance of the assay, N-nitrosopyrrolidine (NPYR), a genotoxic hepatocarcinogen, was tested in 14- or 28-day RDLMN assays. NPYR was orally administered to rats at a daily dose of 25, 50 or 100 mg/kg. One day after the last administration, a portion of the liver was removed and hepatocyte micronucleus (MN) specimens were prepared by the new method recently established by Narumi et al. In addition, a bone marrow MN assay and a histopathological examination of the liver were conducted. The detection of Phospho-Histone H3 was performed by immunohistochemistry to evaluate the proliferation rate of hepatocytes. The results showed significant increase in the number of micronucleated hepatocytes and Phospho-Histone H3-positive cells from the lowest dose in both 14- and 28-day RDLMN assays. On the other hand, the bone marrow MN assay yielded a negative result, which was in accordance with the existing report of the bone marrow MN assay using mice. Upon histopathological examination, inflammatory lesions and hypertrophy were noted, which may explain the increase in the hepatocyte proliferation and the enhancement of MN induction by NPYR. Our findings indicate that the RDLMN assay could be a useful tool for comprehensive risk assessment of carcinogenicity by providing information on both genotoxicity and histopathology when integrated into a general repeat dosing toxicity assay.

  13. Multicenter, noninterventional, post-marketing surveillance study to evaluate dosing of recombinant human follicle-stimulating hormone using the redesigned follitropin alfa pen in women undergoing ovulation induction

    Science.gov (United States)

    Nawroth, Frank; Tandler-Schneider, Andreas; Bilger, Wilma

    2015-01-01

    This prospective, noninterventional, post-marketing surveillance study evaluated doses of recombinant human follicle-stimulating hormone (r-hFSH) using the redesigned follitropin alfa pen in women who were anovulatory or oligomenorrheic and undergoing ovulation induction (OI) alone or OI with intrauterine insemination. The primary endpoint was the proportion of patients who achieved monofollicular or bifollicular development (defined as one or two follicles ≥15 mm). Secondary endpoints included characteristics of ovulation stimulation treatment, such as mean total and mean daily r-hFSH doses. Data were analyzed for 3,193 patients from 30 German fertility centers. The proportion of patients with monofollicular or bifollicular development was 71.1% (n=2,270 of a total of 3,193 patients; intent-to-treat population). The mean±standard deviation total and daily doses of r-hFSH were 696.9±542.5 IU and 61.7±29.4 IU, respectively. The three doses prescribed most frequently were: 37.5 IU (n=703 from N=3,189; 22.0%), 50.0 IU (n=1,056 from N=3,189; 33.1%), and 75.0 IU (n=738 from N=3,189; 23.1%) on the first day of stimulation; and 37.5 IU (n=465 from N=3,189; 14.6%), 50.0 IU (n=922 from N=3,189; 28.9%), and 75.0 IU (n=895 from N=3,189; 28.1%) on the last day of stimulation. This noninterventional, post-marketing surveillance study found that monofollicular or bifollicular development was achieved in 71% of patients studied and the small dose increment (12.5 IU) of the redesigned follitropin alfa pen allowed individualized treatment of women undergoing OI. PMID:25926755

  14. Pharmacokinetic evaluation of pamidronate after oral administration: a study on dose proportionality, absolute bioavailability, and effect of repeated administration

    DEFF Research Database (Denmark)

    Hyldstrup, Lars; Flesch, G; Hauffe, S A

    1993-01-01

    30 minutes at constant infusion rate. Repeated peroral doses (75 and 150 mg) were administered to 12 females (aged 51-70 years) for 10 consecutive days. Urinary excretion of pamidronate after peroral and i.v. administration was used for estimation of pamidronate absorption. Renal excretion...... of pamidronate ranged from 0.01% to 0.35% of dose, with mean values of 0.11, 0.16, and 0.18% for 75, 150, and 300 mg, respectively. After i.v. infusion, the renal excretion of pamidronate was 26-53% of the dose, lower than for other bisphosphonates. The absolute bioavailability was 0.31% (range 0.08-0.7%) after...

  15. A study on evaluation of public dose for hypothetical exposure from industrial sources in major Indian cities

    International Nuclear Information System (INIS)

    Chandrasekaran, S.; Sivasubramanian, K.; Venkatraman, B.

    2016-01-01

    With expanding industrial establishments in India, the requirements for quality Assurance (QA) have become stringent at every stages of process including selection of raw material, manufacturing process and packing and transport. Radiography, a non-destructive method is widely employed for QA testing. Inadvertent handling or loss of these sources may result in exposure of public/workers to higher levels of ionizing radiation. A well planned emergency preparedness is essential to manage any such untoward incidents. Dose estimation to members of public involved is the major challenge as the time available is very short and eases of availability/labs surrounding the location. This paper determines the dose up to 30m distance as prescribed in AERB safety guidelines and using the population data of four major metropolitan cities in India, public dose is also estimated

  16. Evaluation of X ray radiation doses in pediatric examinations of cranial computerized tomography based on optimization studies; Avaliacao das doses de radiacao X em exames pediatricos de tomografia computadorizada de cranio com base em estudos de otimizacao

    Energy Technology Data Exchange (ETDEWEB)

    Daros, Kellen Adriana Curci

    2005-07-01

    This paper identifies the technical conditions for CT examination which offers lowest absorbed dose and to attend the manufacturer recommendations as far the spatial resolution is concerned. The paper evaluates the absorbed dose during cranial CT in up to 6 years children satisfying the technical condition recommended by the manufacturer and routine clinical conditions. The paper also established a quantitative relationship among the absorbed dose and its distribution in the cranial regions of pediatric patients up to 6 years old in a way to estimate the doses subject to optimized conditions

  17. Design and development of an anthropomorphic phantom equipped with detectors in order to evaluate the effective dose E at workplaces: feasibility study

    International Nuclear Information System (INIS)

    Furstoss, Ch.

    2006-11-01

    My PhD study aims to determine the feasibility to design and develop, for photon fields, an anthropomorphic phantom equipped with detectors in order to evaluate the effective dose E at workplaces. First of all, the energy losses within the organs are calculated using the M.C.N.P.X. Monte Carlo code, in order to determine the detection positions within the different organs. Then, to decrease the number of detection positions, the organ contribution to the effective dose is studied. Finally, the characteristics of the detectors to insert and the characteristics of the phantom to use are deduced. The results show that 24 or 23 detection positions, according to the wT values (publication 60 or new recommendations of the ICRP), give a E estimation with an uncertainty of ±15 % from 50 keV to 4 MeV. Moreover, the interest of such an instrument is underlined while comparing the E estimation by the personal dose equivalent Hp to the E estimation by the instrumented phantom when the phantom is irradiated by point sources (worker in front of a glove box for example). Last, after the detector and phantom characteristic determination, two types of detectors and one type of phantom are selected. However, for the detectors mainly, developments are necessary. Follow up this study, the characterization and the adaptation of the detectors to the project would be interesting. Furthermore, the study to mixed photon-neutrons would be required the needs of the radiological protection community. (author)

  18. Dose evaluation from multiple detector outputs using convex optimisation

    International Nuclear Information System (INIS)

    Hashimoto, M.; Iimoto, T.; Kosako, T.

    2011-01-01

    A dose evaluation using multiple radiation detectors can be improved by the convex optimisation method. It enables flexible dose evaluation corresponding to the actual radiation energy spectrum. An application to the neutron ambient dose equivalent evaluation is investigated using a mixed-gas proportional counter. The convex derives the certain neutron ambient dose with certain width corresponding to the true neutron energy spectrum. The range of the evaluated dose is comparable to the error of conventional neutron dose measurement equipments. An application to the neutron individual dose equivalent measurement is also investigated. Convexes of particular dosemeter combinations evaluate the individual dose equivalent better than the dose evaluation of a single dosemeter. The combinations of dosemeters with high orthogonality of their response characteristics tend to provide a good suitability for dose evaluation. (authors)

  19. LUDEP: A Lung Dose Evaluation Program

    International Nuclear Information System (INIS)

    Birchall, A.; Bailey, M.R.; James, A.C.

    1990-06-01

    A Task Group of the ICRP is currently reviewing its dosimetric model for the respiratory tract with the aim of producing a more comprehensive and realistic model which can be used both for dosimetry and bioassay purposes. This in turn requires deposition, clearance, and dosimetry to be treated in a more detailed manner in than in the current model. In order to examine the practical application and radiological implications of the proposed model, a microcomputer program has been developed in a modular form so that changes can be easily included as the model develops. LUDEP (Lung Dose Evaluation Program) is a user-friendly menu-driven program which can be operated on any IBM-compatible PC. It enables the user to calculate (a) doses to each region of the respiratory tract and all other body organs, and (b) excretion rates and retention curves for bioassay purposes. 11 refs., 4 figs., 6 tabs

  20. A dose-response study in animals to evaluate the anticoagulant effect of the stage 2 unfractionated heparin USP monograph change.

    Science.gov (United States)

    Honchel, R; Carraway, J; Gopee, N; Callicott, R; Chen, J; Patton, R; Xu, Q; Zalkkar, J; Laniyonu, A; Krefting, I; Cato, M; Robie-Suh, K; Rieves, R

    2011-08-01

    The United States Pharmacopeia (USP) monograph for unfractionated heparin (UFH) was revised in October 2009. This revision was anticipated, based upon in vitro tests, to reduce UFH potency by approximately 10%. To study the potential in vivo consequences of the monograph change, we evaluated activated partial thromboplastin time (aPTT) and activated clotting time (ACT) responses in animals. Female mini-pigs and monkeys (n=8/species) were administered intravenously 60, 54, 48, or 42 U/kg and 50, 45, 40, or 35 U/kg "old" (pre-USP revision) UFH, respectively, in a Williams 4×4 crossover design. Blood samples for aPTT and ACT were collected at 15 min after dosing. The same study design was then repeated using "new" (post-USP revision) UFH. Mean "new" UFH aPTT and ACT values were generally lower than those for "old" UFH although individual animal responses varied considerably. The aPTT and ACT response was generally dose-proportional for both "old" and "new" UFH. These studies indicate that the USP monograph alteration for UFH may result in a modest reduction in the anticoagulant response across a population, but the variability in animal responses underscores the importance of individualization of clinical UFH dosing and the importance of anticoagulant test monitoring. Published by Elsevier Inc.

  1. Single-dose safety and pharmacokinetic evaluation of fluorocoxib A: pilot study of novel cyclooxygenase-2-targeted optical imaging agent in a canine model

    Science.gov (United States)

    Cekanova, Maria; Uddin, Md. Jashim; Legendre, Alfred M.; Galyon, Gina; Bartges, Joseph W.; Callens, Amanda; Martin-Jimenez, Tomas; Marnett, Lawrence J.

    2012-11-01

    We evaluated preclinical single-dose safety, pharmacokinetic properties, and specific uptake of the new optical imaging agent fluorocoxib A in dogs. Fluorocoxib A, N-[(5-carboxy-X-rhodaminyl)but-4-yl]-2-[1-(4-chlorobenzoyl)-5-methoxy-2-methyl-1H-indol-3-yl]acetamide, selectively binds and inhibits the cyclooxygenase-2 (COX-2) enzyme, which is overexpressed in many cancers. Safety pilot studies were performed in research dogs following intravenous (i.v.) administration of 0.1 and 1 mg/kg fluorocoxib A. Blood and urine samples collected three days after administration of each dose of fluorocoxib A revealed no evidence of toxicity, and no clinically relevant adverse events were noted on physical examination of exposed dogs over that time period. Pharmacokinetic parameters were assessed in additional research dogs from plasma collected at several time points after i.v. administration of fluorocoxib A using high-performance liquid chromatography analysis. The pharmacokinetic studies using 1 mg/kg showed a peak of fluorocoxib A (92±28 ng/ml) in plasma collected at 0.5 h. Tumor specific uptake of fluorocoxib A was demonstrated using a dog diagnosed with colorectal cancer expressing COX-2. Our data support the safe single-dose administration and in vivo efficacy of fluorocoxib A, suggesting a high potential for successful translation to clinical use as an imaging agent for improved tumor detection in humans.

  2. Measurement of spatial dose distribution for evaluation operator dose during nero-interventional procedures

    International Nuclear Information System (INIS)

    Han, Su Chul; Hong, Dong Hee

    2016-01-01

    The spatial dose distribution was measured with ionization chamber as preliminary study to evaluate operator dose and to study dose reduction during neuro-interventional procedures. The zone of operators was divided into four area (45, 135, 225, and 315 degree).We supposed that operator exist on the four area and indicated location of critical organs(eyes, breast, gonad). The spatial doses were measured depending on distance( 80, 100, 120, and 140 cm) and location of critical organs. The spatial doses of area of 225 degree were 114.5 mR/h (eyes location), 143.1 mR/h (breast location) and 147 mR/h (gonad location) in 80 cm. When changed location of x-ray generator, spatial dose increased in 18.1±10.5%, averagely. We certified spatial dose in the operator locations, Using the results of this study, It is feasible to protect operator from radiation in neuro-interventional procedures

  3. Measurement of spatial dose distribution for evaluation operator dose during nero-interventional procedures

    Energy Technology Data Exchange (ETDEWEB)

    Han, Su Chul [Division of Medical Radiation Equipment, Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of); Hong, Dong Hee [Dept. of Radiology Science, Far East University, Eumseong (Korea, Republic of)

    2016-09-15

    The spatial dose distribution was measured with ionization chamber as preliminary study to evaluate operator dose and to study dose reduction during neuro-interventional procedures. The zone of operators was divided into four area (45, 135, 225, and 315 degree).We supposed that operator exist on the four area and indicated location of critical organs(eyes, breast, gonad). The spatial doses were measured depending on distance( 80, 100, 120, and 140 cm) and location of critical organs. The spatial doses of area of 225 degree were 114.5 mR/h (eyes location), 143.1 mR/h (breast location) and 147 mR/h (gonad location) in 80 cm. When changed location of x-ray generator, spatial dose increased in 18.1±10.5%, averagely. We certified spatial dose in the operator locations, Using the results of this study, It is feasible to protect operator from radiation in neuro-interventional procedures.

  4. Evaluation of fixed dose combination of glimepiride and metformin in patients with type 2 diabetes. Results of Russian observational study

    Directory of Open Access Journals (Sweden)

    Natalya Vladislavovna Zaytseva

    2015-04-01

    Full Text Available Aim. To investigate the efficacy and safety of combined glimepiride and metformin therapy in patients with type 2 diabetes mellitus (T2DM. Materials and methods. A multi-centre, open-label, prospective, observational study was conducted. A total of 1200 patients with T2DM inadequately controlled with metformin, glimepiride or combination of metformin + glimepiride were enrolled. Change in serum glycated haemoglobin (HbA1c, fasting plasma glucose (FPG, and postprandial blood glucose (PPG levels; weight; waist circumference and hypoglycemic episodes were evaluated. Results. Baseline HbA1c levels (8.24% ? 0.42% were significantly reduced after 12 weeks of treatment (7.48% ? 0.48% and at the end of the study. (6.88% ? 0.56%. Target HbA1c levels (?7% were achieved in 65.1% of patients at the final visit at 24 weeks. FPG and PPG levels decreased by 1.45 ? 1.14 mmol/l and 2.17 ? 1.27 mmol/l respectively (p < 0.001. No severe hypoglycemic events were reported. Body mass index reduced by 0.85 ? 1.28 kg/m2 (p < 0.001. Conclusion. . Combined glimepiride and metformin therapy significantly improved long-term glycemic control in patients with T2DM during the period of 24 weeks. without additional risk of hypoglycemic events or weight gain.

  5. Evaluation of fixed dose combination of glimepiride and metformin in patients with type 2 diabetes. Results of Russian observational study

    Directory of Open Access Journals (Sweden)

    Natalya Vladislavovna Zaytseva

    2015-04-01

    Full Text Available Aim.To investigate the efficacy and safety of combined glimepiride and metformin therapy in patients with type 2 diabetes mellitus (T2DM.Materials and methods.A multi-centre, open-label, prospective, observational study was conducted. A total of 1200 patients with T2DM inadequately controlled with metformin, glimepiride or combination of metformin + glimepiride were enrolled. Change in serum glycated haemoglobin (HbA1c, fasting plasma glucose (FPG, and postprandial blood glucose (PPG levels; weight; waist circumference and hypoglycemic episodes were evaluated.Results.Baseline HbA1c levels (8.24% ± 0.42% were significantly reduced after 12 weeks of treatment (7.48% ± 0.48% and at the end of the study(6.88% ± 0.56%. Target HbA1c levels (≤7% were achieved in 65.1% of patients at the final visit at 24 weeks. FPG and PPG levels decreased by 1.45 ± 1.14 mmol/l and 2.17 ± 1.27 mmol/l respectively (p < 0.001. No severe hypoglycemic events were reported. Body mass index reduced by 0.85 ± 1.28 kg/m2 (p < 0.001.Conclusion. Combined glimepiride and metformin therapy significantly improved long-term glycemic control in patients with T2DM during the period of 24 weeks without additional risk of hypoglycemic events or weight gain.

  6. Dose evaluation in special fluoroscopy procedures: Hysterosalpingography and Dacryocystography

    International Nuclear Information System (INIS)

    Lopes, Cintya Carolina Barbosa

    2006-04-01

    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)

  7. Clinical implementation and evaluation of the Acuros dose calculation algorithm.

    Science.gov (United States)

    Yan, Chenyu; Combine, Anthony G; Bednarz, Greg; Lalonde, Ronald J; Hu, Bin; Dickens, Kathy; Wynn, Raymond; Pavord, Daniel C; Saiful Huq, M

    2017-09-01

    The main aim of this study is to validate the Acuros XB dose calculation algorithm for a Varian Clinac iX linac in our clinics, and subsequently compare it with the wildely used AAA algorithm. The source models for both Acuros XB and AAA were configured by importing the same measured beam data into Eclipse treatment planning system. Both algorithms were validated by comparing calculated dose with measured dose on a homogeneous water phantom for field sizes ranging from 6 cm × 6 cm to 40 cm × 40 cm. Central axis and off-axis points with different depths were chosen for the comparison. In addition, the accuracy of Acuros was evaluated for wedge fields with wedge angles from 15 to 60°. Similarly, variable field sizes for an inhomogeneous phantom were chosen to validate the Acuros algorithm. In addition, doses calculated by Acuros and AAA at the center of lung equivalent tissue from three different VMAT plans were compared to the ion chamber measured doses in QUASAR phantom, and the calculated dose distributions by the two algorithms and their differences on patients were compared. Computation time on VMAT plans was also evaluated for Acuros and AAA. Differences between dose-to-water (calculated by AAA and Acuros XB) and dose-to-medium (calculated by Acuros XB) on patient plans were compared and evaluated. For open 6 MV photon beams on the homogeneous water phantom, both Acuros XB and AAA calculations were within 1% of measurements. For 23 MV photon beams, the calculated doses were within 1.5% of measured doses for Acuros XB and 2% for AAA. Testing on the inhomogeneous phantom demonstrated that AAA overestimated doses by up to 8.96% at a point close to lung/solid water interface, while Acuros XB reduced that to 1.64%. The test on QUASAR phantom showed that Acuros achieved better agreement in lung equivalent tissue while AAA underestimated dose for all VMAT plans by up to 2.7%. Acuros XB computation time was about three times faster than AAA for VMAT plans, and

  8. Evaluation of radiation doses from MDCT-imaging in otolaryngology

    International Nuclear Information System (INIS)

    Yamauchi-Kawaura, C.; Fujii, K.; Aoyama, T.; Yamauchi, M.; Koyama, S.

    2009-01-01

    The purpose of this study was to clarify patient doses in the current otolaryngological multi-detector row computed tomography (MDCT) examinations. Patient doses were measured with an in-phantom dosimetry system which was composed of 48 photodiode dosemeters embedded within an anthropomorphic phantom. Organ and effective doses were evaluated according to the International Commission on Radiological Protection Publication 103. In neck CT, doses for salivary glands and for thyroid were high, 7.6-29.9 and 13.4-60.3 mGy, respectively. In sinus CT, brain and lens doses were high, 7.6-24.6 and 10.6-32.0 mGy, respectively, and in inner ear CT, lens dose was 8.0-35.3 mGy. Effective doses were 1.8-6.6 mSv in neck CT, 0.5-0.9 mSv in sinus CT and 0.3-0.6 mSv in inner ear CT. The present dose data would be used to estimate radiation risks for patients undergoing otolaryngological MDCT examinations. (authors)

  9. Equivalent uniform dose concept evaluated by theoretical dose volume histograms for thoracic irradiation.

    Science.gov (United States)

    Dumas, J L; Lorchel, F; Perrot, Y; Aletti, P; Noel, A; Wolf, D; Courvoisier, P; Bosset, J F

    2007-03-01

    The goal of our study was to quantify the limits of the EUD models for use in score functions in inverse planning software, and for clinical application. We focused on oesophagus cancer irradiation. Our evaluation was based on theoretical dose volume histograms (DVH), and we analyzed them using volumetric and linear quadratic EUD models, average and maximum dose concepts, the linear quadratic model and the differential area between each DVH. We evaluated our models using theoretical and more complex DVHs for the above regions of interest. We studied three types of DVH for the target volume: the first followed the ICRU dose homogeneity recommendations; the second was built out of the first requirements and the same average dose was built in for all cases; the third was truncated by a small dose hole. We also built theoretical DVHs for the organs at risk, in order to evaluate the limits of, and the ways to use both EUD(1) and EUD/LQ models, comparing them to the traditional ways of scoring a treatment plan. For each volume of interest we built theoretical treatment plans with differences in the fractionation. We concluded that both volumetric and linear quadratic EUDs should be used. Volumetric EUD(1) takes into account neither hot-cold spot compensation nor the differences in fractionation, but it is more sensitive to the increase of the irradiated volume. With linear quadratic EUD/LQ, a volumetric analysis of fractionation variation effort can be performed.

  10. Evaluation of repeated dose micronucleus assays of the liver and gastrointestinal tract using potassium bromate: a report of the collaborative study by CSGMT/JEMS.MMS.

    Science.gov (United States)

    Okada, Emiko; Fujiishi, Yohei; Narumi, Kazunori; Kado, Shoichi; Wako, Yumi; Kawasako, Kazufumi; Kaneko, Kimiyuki; Ohyama, Wakako

    2015-03-01

    The food additive potassium bromate (KBrO3) is known as a renal carcinogen and causes chromosomal aberrations in vitro without metabolic activation and in vivo in hematopoietic and renal cells. As a part of a collaborative study by the Mammalian Mutagenicity Study group, which is a subgroup of the Japanese Environmental Mutagen Society, we administered KBrO3 to rats orally for 4, 14, and 28 days and examined the micronucleated (MNed) cell frequency in the liver, glandular stomach, colon, and bone marrow to confirm whether the genotoxic carcinogen targeting other than liver and gastrointestinal (GI) tract was detected by the repeated dose liver and GI tract micronucleus (MN) assays. In our study, animals treated with KBrO3 showed some signs of toxicity in the kidney and/or stomach. KBrO3 did not increase the frequency of MNed cells in the liver and colon in any of the repeated dose studies. However, KBrO3 increased the frequency of MNed cells in the glandular stomach and bone marrow. Additionally, the MNed cell frequency in the glandular stomach was not significantly affected by the difference in the length of the administration period. These results suggest that performing the MN assay using the glandular stomach, which is the first tissue to contact agents after oral ingestion, is useful for evaluating the genotoxic potential of chemicals and that the glandular stomach MN assay could be integrated into general toxicity studies. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. Doses in mammography. Preliminary study

    International Nuclear Information System (INIS)

    Marquez P, F.; Acosta R, N.; Universidad Nacional Mayor de San Marcos, Lima; Benavente, T.; Universidad Nacional Mayor de San Marcos, Lima; Poma, M.

    2002-01-01

    Mammography is the most important method to detect lesions in the breast with this technique one can detect small tumours before clear clinical symptoms appear. Mammographic image of require high quality standards due that the extremely low contrast between the normal and pathological areas in the breast, eg.g., they have similar attenuation and absorption coefficient. The x-ray mammographic systems, used in this study are Senographe 500t and Senographe DMR, a detector with a RadCal ionization chambers calibrated to the qualities of mammographic x-ray beams, and a breast simulator that is a phantoms of polymethylmethacrylate (PMMA) of several thicknesses with the equivalence of 50% of the glandular tissue. The results obtained indicate that the values of doses at the entrance surface of a breast (DES) are greater the reference value 20 mGy to 5,0 cm of PMMA and the values of the mean glandular dose (MGD) exceed the reference value of 2,1 mGy for 5,1 cm of compressed thick breast. We consider that the values high of the EDS and MGD are due that the x-ray systems no meeting in good condition or for used of x-ray spectra no suitable, so is recommendable be carried out test of quality control to the x-ray systems and also realize studies, or characterize the of x-ray mammographic spectra

  12. Multicenter, noninterventional, post-marketing surveillance study to evaluate dosing of recombinant human follicle-stimulating hormone using the redesigned follitropin alfa pen in women undergoing ovulation induction

    Directory of Open Access Journals (Sweden)

    Nawroth F

    2015-04-01

    Full Text Available Frank Nawroth,1 Andreas Tandler-Schneider,2 Wilma Bilger3 1Centre for Reproductive and Prenatal Medicine, Endocrinology and Osteology, Hamburg, Germany; 2Center for Reproductive Medicine, Fertility Center Berlin, Berlin, Germany; 3Medical Affairs, Fertility, Endocrinology and General Medicine, Merck Serono GmbH, Darmstadt, Germany (an affiliate of Merck KGaA, Darmstadt, Germany Abstract: This prospective, noninterventional, post-marketing surveillance study evaluated doses of recombinant human follicle-stimulating hormone (r-hFSH using the redesigned follitropin alfa pen in women who were anovulatory or oligomenorrheic and undergoing ovulation induction (OI alone or OI with intrauterine insemination. The primary endpoint was the proportion of patients who achieved monofollicular or bifollicular development (defined as one or two follicles 15 mm. Secondary endpoints included characteristics of ovulation stimulation treatment, such as mean total and mean daily r-hFSH doses. Data were analyzed for 3,193 patients from 30 German fertility centers. The proportion of patients with monofollicular or bifollicular development was 71.1% (n=2,270 of a total of 3,193 patients; intent-to-treat population. The mean±standard deviation total and daily doses of r-hFSH were 696.9±542.5 IU and 61.7±29.4 IU, respectively. The three doses prescribed most frequently were: 37.5 IU (n=703 from N=3,189; 22.0%, 50.0 IU (n=1,056 from N=3,189; 33.1%, and 75.0 IU (n=738 from N=3,189; 23.1% on the first day of stimulation; and 37.5 IU (n=465 from N=3,189; 14.6%, 50.0 IU (n=922 from N=3,189; 28.9%, and 75.0 IU (n=895 from N=3,189; 28.1% on the last day of stimulation. This noninterventional, post-marketing surveillance study found that monofollicular or bifollicular development was achieved in 71% of patients studied and the small dose increment (12.5 IU of the redesigned follitropin alfa pen allowed individualized treatment of women undergoing OI. Keywords: ovulation

  13. Evaluation of the occupational dose in hemodynamic procedures

    International Nuclear Information System (INIS)

    Silva, Amanda J. da; Fernandes, Ivani M.; Sordi, Gian Maria A.A.; Carneiro, Janete C. Gaburo

    2010-01-01

    The purpose of this study was to evaluate the dose received by health professionals in a hemodynamic service. It was necessary to know the profile of these professional, to carry out a survey the occupational external doses during the years 2000 to 2009 and to evaluate the distribution of the effective dose from the special procedures guided by fluoroscopy. A self-applied questionnaire was used to delineate the profile of health professionals, taking into account variables such as gender, age, individual monitoring time, number of jobs and tasks performed in the sector. In addition, it was performed an examination of the external individual monitoring doses from the records of the institution. The sample was composed of 35 professionals, 11 males and 24 females, with mean age of (43.0 +- 10.4) years. The average monitoring time of individuals analyzed within the institution was (11.3 +- 9.1) years, considering the period before the study. The minimum record dose level was 0.2 mSv and the maximum dose was 22.7 mSv. Doctors and nursing assistants were the professionals more exposed to radiation, due probably remaining closer to the examination table and X-ray tube during the interventional procedure. (author)

  14. Open-label, dose escalation phase I study in healthy volunteers to evaluate the safety and pharmacokinetics of a human monoclonal antibody to Clostridium difficile toxin A.

    Science.gov (United States)

    Taylor, Claribel P; Tummala, Sanjeev; Molrine, Deborah; Davidson, Lisa; Farrell, Richard J; Lembo, Anthony; Hibberd, Patricia L; Lowy, Israel; Kelly, Ciaran P

    2008-06-25

    Recent data suggest that Clostridium difficile-associated diarrhea is becoming more severe and difficult to treat. Antibody responses to C. difficile toxin A are protective against symptomatic disease and recurrence. We examined the safety and pharmacokinetics (pk) of a novel neutralizing human monoclonal antibody against C. difficile toxin A (CDA1) in healthy adults. Five cohorts with 6 subjects each received a single intravenous infusion of CDA1 at escalating doses of 0.3, 1, 5, 10, and 20 mg/kg. Safety evaluations took place on days 1, 2, 3, 7, 14, 28, and 56 post-infusion. Samples for pk analysis were obtained before and after infusion, and at each safety evaluation. Serum CDA1 antibody concentrations and human anti-human antibody (HAHA) titers were measured with enzyme-linked immunosorbent assays. A noncompartmental model was used for pk analysis. Thirty subjects were enrolled. The median age was 27.5 yrs. There were no serious adverse events (AE) related to CDA1. Twenty-one of the 48 reported non-serious adverse events were possibly related to CDA1, and included transient blood pressure changes requiring no treatment, nasal congestion, headache, abdominal cramps, nausea, and self-limited diarrhea. Serum CDA1 concentrations increased with escalating doses: mean C(max) ranged from 6.82 microg/ml for the 0.3 mg/kg cohort to 511 microg/ml for the 20 mg/kg cohort. The geometric mean values of the half-life of CDA1 ranged between 25.3 and 31.8 days, and the volume of distribution approximated serum. No subject formed detectable HAHA titers. Administration of CDA1 as a single intravenous infusion was safe and well tolerated. C(max) increased proportionally with increasing doses. A randomized study of CDA1 in patients with C. difficile associated diarrhea is underway.

  15. Evaluation of radiation dose and image quality of CT scan for whole-body pediatric PET/CT: A phantom study

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Ching-Ching, E-mail: cyang@tccn.edu.tw [Department of Medical Imaging and Radiological Sciences, Tzu-Chi College of Technology, 970, Hualien, Taiwan (China); Liu, Shu-Hsin [Department of Nuclear Medicine, Buddhist Tzu-Chi General Hospital, 970, Hualien, Taiwan and Department of Medical Imaging and Radiological Sciences, Tzu-Chi College of Technology, 970, Hualien, Taiwan (China); Mok, Greta S. P. [Biomedical Imaging Laboratory, Department of Electrical and Computer Engineering, Faculty of Science and Technology, University of Macau, Macau (China); Wu, Tung-Hsin [Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, 112, Taipei, Taiwan (China)

    2014-09-15

    Purpose: This study aimed to tailor the CT imaging protocols for pediatric patients undergoing whole-body PET/CT examinations with appropriate attention to radiation exposure while maintaining adequate image quality for anatomic delineation of PET findings and attenuation correction of PET emission data. Methods: The measurements were made by using three anthropomorphic phantoms representative of 1-, 5-, and 10-year-old children with tube voltages of 80, 100, and 120 kVp, tube currents of 10, 40, 80, and 120 mA, and exposure time of 0.5 s at 1.75:1 pitch. Radiation dose estimates were derived from the dose-length product and were used to calculate risk estimates for radiation-induced cancer. The influence of image noise on image contrast and attenuation map for CT scans were evaluated based on Pearson's correlation coefficient and covariance, respectively. Multiple linear regression methods were used to investigate the effects of patient age, tube voltage, and tube current on radiation-induced cancer risk and image noise for CT scans. Results: The effective dose obtained using three anthropomorphic phantoms and 12 combinations of kVp and mA ranged from 0.09 to 4.08 mSv. Based on our results, CT scans acquired with 80 kVp/60 mA, 80 kVp/80 mA, and 100 kVp/60 mA could be performed on 1-, 5-, and 10-year-old children, respectively, to minimize cancer risk due to CT scans while maintaining the accuracy of attenuation map and CT image contrast. The effective doses of the proposed protocols for 1-, 5- and 10-year-old children were 0.65, 0.86, and 1.065 mSv, respectively. Conclusions: Low-dose pediatric CT protocols were proposed to balance the tradeoff between radiation-induced cancer risk and image quality for patients ranging in age from 1 to 10 years old undergoing whole-body PET/CT examinations.

  16. Mathematical model for evaluation of dose-rate effect on biological responses to low dose γ-radiation

    International Nuclear Information System (INIS)

    Ogata, H.; Kawakami, Y.; Magae, J.

    2003-01-01

    Full text: To evaluate quantitative dose-response relationship on the biological response to radiation, it is necessary to consider a model including cumulative dose, dose-rate and irradiation time. In this study, we measured micronucleus formation and [ 3 H] thymidine uptake in human cells as indices of biological response to gamma radiation, and analyzed mathematically and statistically the data for quantitative evaluation of radiation risk at low dose/low dose-rate. Effective dose (ED x ) was mathematically estimated by fitting a general function of logistic model to the dose-response relationship. Assuming that biological response depends on not only cumulative dose but also dose-rate and irradiation time, a multiple logistic function was applied to express the relationship of the three variables. Moreover, to estimate the effect of radiation at very low dose, we proposed a modified exponential model. From the results of fitting curves to the inhibition of [ 3 H] thymidine uptake and micronucleus formation, it was obvious that ED 50 in proportion of inhibition of [ 3 H] thymidine uptake increased with longer irradiation time. As for the micronuclei, ED 30 also increased with longer irradiation times. These results suggest that the biological response depends on not only total dose but also irradiation time. The estimated response surface using the three variables showed that the biological response declined sharply when the dose-rate was less than 0.01 Gy/h. These results suggest that the response does not depend on total cumulative dose at very low dose-rates. Further, to investigate the effect of dose-rate within a wider range, we analyzed the relationship between ED x and dose-rate. Fitted curves indicated that ED x increased sharply when dose-rate was less than 10 -2 Gy/h. The increase of ED x signifies the decline of the response or the risk and suggests that the risk approaches to 0 at infinitely low dose-rate

  17. A Retrospective Study Evaluating the Effect of Low Doses of Perineural Dexamethasone on Ropivacaine Brachial Plexus Peripheral Nerve Block Analgesic Duration.

    Science.gov (United States)

    Schnepper, Gregory D; Kightlinger, Benjamin I; Jiang, Yunyun; Wolf, Bethany J; Bolin, Eric D; Wilson, Sylvia H

    2017-09-23

    Examination of the effectiveness of perineural dexamethasone administered in very low and low doses on ropivacaine brachial plexus block duration. Retrospective evaluation of brachial plexus block duration in a large cohort of patients receiving peripheral nerve blocks with and without perineural dexamethasone in a prospectively collected quality assurance database. A single academic medical center. A total of 1,942 brachial plexus blocks placed over a 16-month period were reviewed. Demographics, nerve block location, and perineural dexamethasone utilization and dose were examined in relation to block duration. Perineural dexamethasone was examined as none (0 mg), very low dose (2 mg or less), and low dose (greater than 2 mg to 4 mg). Continuous catheter techniques, local anesthetics other than ropivacaine, and block locations with fewer than 15 subjects were excluded. Associations between block duration and predictors of interest were examined using multivariable regression models. A subgroup analysis of the impact of receiving dexamethasone on block duration within each block type was also conducted using a univariate linear regression approach. A total of 1,027 subjects were evaluated. More than 90% of brachial plexus blocks contained perineural dexamethasone (≤4 mg), with a median dose of 2 mg. Increased block duration was associated with receiving any dose of perineural dexamethasone (P block duration did not differ with very low- or low-dose perineural dexamethasone after controlling for other factors (P = 0.420). Perineural dexamethasone prolonged block duration compared with ropivacaine alone; however, duration was not greater with low-dose compared with very low-dose perineural dexamethasone. © 2017 American Academy of Pain Medicine. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com

  18. Effects of dose reduction on multi-detector computed tomographic images in evaluating the maxilla and mandible for pre-surgical implant planning: a cadaveric study.

    Science.gov (United States)

    Koizumi, Hiroshi; Sur, Jaideep; Seki, Kenji; Nakajima, Koh; Sano, Tsukasa; Okano, Tomohiro

    2010-08-01

    To assess effects of dose reduction on image quality in evaluating maxilla and mandible for pre-surgical implant planning using cadavers. Six cadavers were used for the study using multi-detector computed tomography (CT) operated at 120 kV and the variable tube current of 80, 40, 20 and 10 mA. A slice thickness of 0.625 mm and pitch 1 were used. Multi-planar images perpendicular and parallel to dentitions were created. The images were evaluated by five oral radiologists in terms of visibility of the anatomical landmarks including alveolar crest, mandibular canal, floors of the maxillary sinus and nasal cavity, contours/cortical layer of jaw bones and the details of trabecular bone. Observers were asked to determine the quality of the images in comparison with 80 mA images based on the criteria: excellent, good, fair or non-diagnostic. The average scores of all observers were calculated for each specimen in all exposure conditions. The 40 mA images could visualize such landmarks and were evaluated to be same or almost equivalent in quality to the 80 mA images. Even the 20 mA images could be accepted just for diagnostic purpose for implant with substantial deterioration of the image quality. The 10 mA images may not be accepted because of the obscured contour caused by image noise. Significant dose reduction by lowering mA can be utilized for pre-surgical implant planning in multi-detector CT.

  19. Evaluation of occupational and patient radiation doses in orthopedic surgery

    International Nuclear Information System (INIS)

    Sulieman, A.; Habiballah, B.; Abdelaziz, I.; Alzimami, K.; Osman, H.; Omer, H.; Sassi, S. A.

    2014-08-01

    Orthopedists are exposed to considerable radiation dose during orthopedic surgeries procedures. The staff is not well trained in radiation protection aspects and its related risks. In Sudan, regular monitoring services are not provided for all staff in radiology or interventional personnel. It is mandatory to measure staff and patient exposure in order to radiology departments. The main objectives of this study are: to measure the radiation dose to patients and staff during (i) Dynamic Hip Screw (Dhs) and (i i) Dynamic Cannula Screw (Dcs); to estimate the risk of the aforementioned procedures and to evaluate entrance surface dose (ESD) and organ dose to specific radiosensitive patients organs. The measurements were performed in Medical Corps Hospital, Sudan. The dose was measured for unprotected organs of staff and patient as well as scattering radiation. Calibrated Thermoluminescence dosimeters (TLD-Gr-200) of lithium fluoride (LiF:Mg, Cu,P) were used for ESD measurements. TLD signal are obtained using automatic TLD Reader model (Plc-3). The mean patients doses were 0.46 mGy and 0.07 for Dhs and Dcs procedures, respectively. The mean staff doses at the thyroid and chest were 4.69 mGy and 1.21 mGy per procedure. The mean radiation dose for staff was higher in Dhs compared to Dcs. This can be attributed to the long fluoroscopic exposures due to the complication of the procedures. Efforts should be made to reduce radiation exposure to orthopedic patients, and operating surgeons especially those with high work load. Staff training and regular monitoring will reduce the radiation dose for both patients and staff. (Author)

  20. Evaluation of occupational and patient radiation doses in orthopedic surgery

    Energy Technology Data Exchange (ETDEWEB)

    Sulieman, A. [Salman bin Abdulaziz University, College of Applied Medical Sciences, Radiology and Medical Imaging Department, P.O. Box 422, Alkharj (Saudi Arabia); Habiballah, B.; Abdelaziz, I. [Sudan Univesity of Science and Technology, College of Medical Radiologic Sciences, P.O. Box 1908, Khartoum (Sudan); Alzimami, K. [King Saud University, College of Applied Medical Sciences, Radiological Sciences Department, P.O. Box 10219, 11433 Riyadh (Saudi Arabia); Osman, H. [Taif University, College of Applied Medical Science, Radiology Department, Taif (Saudi Arabia); Omer, H. [University of Dammam, Faculty of Medicine, Dammam (Saudi Arabia); Sassi, S. A., E-mail: Abdelmoneim_a@yahoo.com [Prince Sultan Medical City, Department of Medical Physics, Riyadh (Saudi Arabia)

    2014-08-15

    Orthopedists are exposed to considerable radiation dose during orthopedic surgeries procedures. The staff is not well trained in radiation protection aspects and its related risks. In Sudan, regular monitoring services are not provided for all staff in radiology or interventional personnel. It is mandatory to measure staff and patient exposure in order to radiology departments. The main objectives of this study are: to measure the radiation dose to patients and staff during (i) Dynamic Hip Screw (Dhs) and (i i) Dynamic Cannula Screw (Dcs); to estimate the risk of the aforementioned procedures and to evaluate entrance surface dose (ESD) and organ dose to specific radiosensitive patients organs. The measurements were performed in Medical Corps Hospital, Sudan. The dose was measured for unprotected organs of staff and patient as well as scattering radiation. Calibrated Thermoluminescence dosimeters (TLD-Gr-200) of lithium fluoride (LiF:Mg, Cu,P) were used for ESD measurements. TLD signal are obtained using automatic TLD Reader model (Plc-3). The mean patients doses were 0.46 mGy and 0.07 for Dhs and Dcs procedures, respectively. The mean staff doses at the thyroid and chest were 4.69 mGy and 1.21 mGy per procedure. The mean radiation dose for staff was higher in Dhs compared to Dcs. This can be attributed to the long fluoroscopic exposures due to the complication of the procedures. Efforts should be made to reduce radiation exposure to orthopedic patients, and operating surgeons especially those with high work load. Staff training and regular monitoring will reduce the radiation dose for both patients and staff. (Author)

  1. Dose evaluation in diagnostic for computerized tomography

    International Nuclear Information System (INIS)

    Flores, W.; Borges, J.C.; Mota, H.

    1998-01-01

    The patients which are subjected to computerized tomography tests are exposed to relatively high doses given as result doses on organs that are not matter to test. It was realized a dose levels raising in patients subjected to tests by T C, utilizing to measure this magnitude, TLD-100 thermoluminescent dosemeters which were put directly on the patient, in eye regions, thyroid, breast and navel; founding doses fluctuating between 29.10-49.39 mGy in organs examined and dose values between 0.21-29.10 mGy for organs that no matter to test. The applications of ionizing radiations in medicine do not have dose limits, but paying attention to the radiological protection optimization principle, it is recommended the use of clothes to anti-rays protection for zones not examined, getting with this to reduce the level doses as low as possible, without this to diminish the test quality. (Author)

  2. Investigation of practical approaches to evaluating cumulative dose for cone beam computed tomography (CBCT) from standard CT dosimetry measurements: a Monte Carlo study.

    Science.gov (United States)

    Abuhaimed, Abdullah; Martin, Colin J; Sankaralingam, Marimuthu; Gentle, David J

    2015-07-21

    A function called Gx(L) was introduced by the International Commission on Radiation Units and Measurements (ICRU) Report-87 to facilitate measurement of cumulative dose for CT scans within long phantoms as recommended by the American Association of Physicists in Medicine (AAPM) TG-111. The Gx(L) function is equal to the ratio of the cumulative dose at the middle of a CT scan to the volume weighted CTDI (CTDIvol), and was investigated for conventional multi-slice CT scanners operating with a moving table. As the stationary table mode, which is the basis for cone beam CT (CBCT) scans, differs from that used for conventional CT scans, the aim of this study was to investigate the extension of the Gx(L) function to CBCT scans. An On-Board Imager (OBI) system integrated with a TrueBeam linac was simulated with Monte Carlo EGSnrc/BEAMnrc, and the absorbed dose was calculated within PMMA, polyethylene (PE), and water head and body phantoms using EGSnrc/DOSXYZnrc, where the body PE body phantom emulated the ICRU/AAPM phantom. Beams of width 40-500 mm and beam qualities at tube potentials of 80-140 kV were studied. Application of a modified function of beam width (W) termed Gx(W), for which the cumulative dose for CBCT scans f (0) is normalized to the weighted CTDI (CTDIw) for a reference beam of width 40 mm, was investigated as a possible option. However, differences were found in Gx(W) with tube potential, especially for body phantoms, and these were considered to be due to differences in geometry between wide beams used for CBCT scans and those for conventional CT. Therefore, a modified function Gx(W)100 has been proposed, taking the form of values of f (0) at each position in a long phantom, normalized with respect to dose indices f 100(150)x measured with a 100 mm pencil ionization chamber within standard 150 mm PMMA phantoms, using the same scanning parameters, beam widths and positions within the phantom. f 100(150)x averages the dose resulting from

  3. Evaluation of a pharmacogenetic-based warfarin dosing algorithm in patients with low time in therapeutic range - study protocol for a randomized controlled trial.

    Science.gov (United States)

    Marcatto, Leiliane Rodrigues; Sacilotto, Luciana; Bueno, Carolina Tosin; Facin, Mirella; Strunz, Celia Maria Cassaro; Darrieux, Francisco Carlos Costa; Scanavacca, Maurício Ibrahim; Krieger, Jose Eduardo; Pereira, Alexandre Costa; Santos, Paulo Caleb Junior Lima

    2016-11-17

    Time in therapeutic range (TTR) is a measurement of quality of warfarin therapy and lower TTR values (algorithm specifically calibrated for a Brazilian patient sample. The aims of this study are: to evaluate the impact of a genetic-based algorithm, compared to traditional anticoagulation, in the time to achieve the therapeutic target and in TTR percentage; and to assess the cost-effectiveness of genotype-guided warfarin dosing in a specific cohort of patients with low TTR (algorithm will be used. At the second, third, fourth and fifth consultations (with an interval of 7 days each) INR will be measured and, if necessary, the dose will be adjusted based on guidelines. Afterwards, patients who are INR stable will begin measuring their INR in 30 day intervals; if the patient's INR is not stable, the patient will return in 7 days for a new measurement of the INR. Outcomes measures will include the time to achieve the therapeutic target and the percentage of TTR at 4 and 12 weeks. In addition, as a secondary end-point, pharmacoeconomic analysis will be carried out. Ethical approval was granted by the Ethics Committee for Medical Research on Human Beings of the Clinical Hospital of the University of São Paulo Medical School. This randomized study will include patients with low TTR and it will evaluate whether a population-specific genetic algorithm might be more effective than traditional anticoagulation for a selected group of poorly anticoagulated patients. ClinicalTrials.gov, NCT02592980 . Registered on 29 October 2015.

  4. Evaluation of the repeated-dose liver micronucleus assay using 2,4-dinitrotoluene: a report of a collaborative study by CSGMT/JEMS.MMS.

    Science.gov (United States)

    Maeda, Akihisa; Tsuchiyama, Hiromi; Asaoka, Yoshiji; Hirakata, Mikito; Miyoshi, Tomoya; Oshida, Keiyu; Miyamoto, Yohei

    2015-03-01

    The liver micronucleus assay using young adult rats has the potential to detect liver carcinogens by repeated dosing, and could be expected to be integrated into repeated-dose toxicity studies using a hepatocyte isolation method without the traditional in situ collagenase perfusion. In this study, to assess the performance of the repeated-dose liver micronucleus assay, 2,4-dinitrotoluene (DNT), which is a rodent liver carcinogen, was administered orally to male rats at doses of 50, 100 and 200 mg/kg/day once daily for 14 or 28 consecutive days, and the frequencies of micronucleated hepatocytes (MNHEPs) and micronucleated immature erythrocytes (MNIMEs) were examined. Significant increases in the MNHEPs were observed at 50 mg/kg/day or more in the 14-day treatment, and 50 and 100 mg/kg/day in the 28-day treatment. These increases were dependent on both the dose and the number of administrations, which indicates the possibility that the MNHEPs accumulate as a result of repeated dosing. In contrast, no increase in the MNIMEs was observed. In conclusion, the repeated-dose liver micronucleus assay using young adult rats is sufficiently sensitive to detect the genotoxicity of 2,4-DNT at a low dose.

  5. 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.

  6. Evaluation of effective dose and excess lifetime cancer risk from ...

    African Journals Online (AJOL)

    Evaluation of effective dose and excess lifetime cancer risk from indoor and outdoor gamma dose rate of university of Port Harcourt Teaching Hospital, Rivers State. ... Therefore, the management of University of Port Harcourt teaching hospital ...

  7. Evaluation of the effective dose and image quality of low-dose multi-detector CT for orthodontic treatment planning

    International Nuclear Information System (INIS)

    Chung, Gi Chung; Han, Won Jeong; Kim, Eun Kyung

    2010-01-01

    This study was designed to compare the effective doses from low-dose and standard-dose multi-detector CT (MDCT) scanning protocols and evaluate the image quality and the spatial resolution of the low-dose MDCT protocols for clinical use. 6-channel MDCT scanner (Siemens Medical System, Forschheim, Germany), was used for this study. Protocol of the standard-dose MDCT for the orthodontic analysis was 130 kV, 35 mAs, 1.25 mm slice width, 0.8 pitch. Those of the low-dose MDCT for orthodontic analysis and orthodontic surgery were 110 kV, 30 mAs, 1.25 mm slice width, 0.85 pitch and 110 kV, 45 mAs, 2.5 mm slice width, 0.85 pitch. Thermoluminescent dosimeters (TLDs) were placed at 31 sites throughout the levels of adult female ART head and neck phantom. Effective doses were calculated according to ICRP 1990 and 2007 recommendations. A formalin-fixed cadaver and AAPM CT performance phantom were scanned for the evaluation of subjective image quality and spatial resolution. Effective doses in μSv (E2007) were 699.1, 429.4 and 603.1 for standard-dose CT of orthodontic treatment, low-dose CT of orthodontic analysis, and low-dose CT of orthodontic surgery, respectively. The image quality from the low-dose protocol were not worse than those from the standard-dose protocol. The spatial resolutions of both standard-dose and low-dose CT images were acceptable. From the above results, it can be concluded that the low-dose MDCT protocol is preferable in obtaining CT images for orthodontic analysis and orthodontic surgery.

  8. Evaluation of the effective dose and image quality of low-dose multi-detector CT for orthodontic treatment planning

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Gi Chung; Han, Won Jeong; Kim, Eun Kyung [Department of Oral and Maxillofacial Radiology, School of Dentistry, Dankook University, Cheonan (Korea, Republic of)

    2010-03-15

    This study was designed to compare the effective doses from low-dose and standard-dose multi-detector CT (MDCT) scanning protocols and evaluate the image quality and the spatial resolution of the low-dose MDCT protocols for clinical use. 6-channel MDCT scanner (Siemens Medical System, Forschheim, Germany), was used for this study. Protocol of the standard-dose MDCT for the orthodontic analysis was 130 kV, 35 mAs, 1.25 mm slice width, 0.8 pitch. Those of the low-dose MDCT for orthodontic analysis and orthodontic surgery were 110 kV, 30 mAs, 1.25 mm slice width, 0.85 pitch and 110 kV, 45 mAs, 2.5 mm slice width, 0.85 pitch. Thermoluminescent dosimeters (TLDs) were placed at 31 sites throughout the levels of adult female ART head and neck phantom. Effective doses were calculated according to ICRP 1990 and 2007 recommendations. A formalin-fixed cadaver and AAPM CT performance phantom were scanned for the evaluation of subjective image quality and spatial resolution. Effective doses in {mu}Sv (E2007) were 699.1, 429.4 and 603.1 for standard-dose CT of orthodontic treatment, low-dose CT of orthodontic analysis, and low-dose CT of orthodontic surgery, respectively. The image quality from the low-dose protocol were not worse than those from the standard-dose protocol. The spatial resolutions of both standard-dose and low-dose CT images were acceptable. From the above results, it can be concluded that the low-dose MDCT protocol is preferable in obtaining CT images for orthodontic analysis and orthodontic surgery.

  9. Dose reduction and optimization studies (ALARA) at nuclear power facilities

    International Nuclear Information System (INIS)

    Baum, J.W.; Meinhold, C.B.

    1983-01-01

    Brookhaven National Laboratory (BNL) has been commissioned by the Nuclear Regulatory Commission (NRC) to study dose-reduction techniques and effectiveness of as low as reasonably achievable (ALARA) planning at LWR plants. These studies have the following objectives: identify high-dose maintenance tasks; identify dose-reduction techniques; examine incentives for dose reduction; evaluate cost-effectiveness and optimization of dose-reduction techniques; and compile an ALARA handbook on data, engineering modifications, cost-effectiveness calculations, and other information of interest to ALARA practioners

  10. Study of dose evaluation method

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2013-08-15

    In 2012 fiscal year, JNES participated in the working team for the new regulatory standards of the nuclear power plant by the Nuclear Regulation Authority, and discussed the basic requirements and details of the requirements in new regulatory standards (design basis event and severe accident). (author)

  11. Dose evaluation and risk estimation for secondary cancer in contralateral breast and a study of correlation between thorax shape and dose to organs at risk following tangentially breast irradiation during deep inspiration breath-hold and free breathing

    International Nuclear Information System (INIS)

    Johansen, Safora; Vikstroem, Johan; Blihovde Hjelstuen, Mari Helene; Mjaaland, Ingvil; Dybvik, Kjell Ivar; Olsen, Dag Rune

    2011-01-01

    Purpose: To assess the impact of using breathing adapted radiotherapy on contralateral breast (CB) dose, to relate the thorax shape with the dose to the organs at risk (OARs) and to predict the risk for induced malignancies in CB using linear and non-linear models, following tangential irradiation of breast. Material and methods. Sixteen patients with stage I-II breast cancer treatment planned with tangential fields using deep inspiration breath hold (DIBH) and free breathing (FB) techniques were included in this analysis. The dose results mainly based on DVH analysis were compared. Four parameters were defined to describe thoracic shape. Excess relative risk (ERR) for cancer induction in CB, employing linear and non-linear models was calculated. Results. Average CB volumes exposed to a dose of 1 Gy is 1.3 times higher in DIBH plans than in FB plans. No significant difference in average V3Gy and V5Gy for DIBH and FB plans is observed. The average mean CB dose for DIBH and FB plans is 0.33 and 0.28 Gy, respectively. No correlation between thorax shape parameters and mean OARs dose is observed. The estimated average mean ERR with linear model is lower in FB plans (0.12) than for the DIBH plans (0.14). The estimated ERR with non-linear model is 0.14 for DIBH plans and 0.15 for FB plans. Conclusion. No significant difference in CB dose between DIBH and FB plans is observed. The four thorax shape parameters defined in this study can not be related to the dose at OARs using DIBH and FB radiation techniques. The ERR estimates for secondary CB cancer are nearly the same for FB and DIBH planning when using a linear and non-linear risk prediction models

  12. Fetal dose evaluation during breast cancer radiotherapy

    International Nuclear Information System (INIS)

    Antypas, Christos; Sandilos, Panagiotis; Kouvaris, John; Balafouta, Ersi; Karinou, Eleftheria; Kollaros, Nikos; Vlahos, Lambros

    1998-01-01

    Purpose: The aim of the work was to estimate the radiation dose delivered to the fetus in a pregnant patient irradiated for breast cancer. Methods and Materials: A 45-year woman was treated for left breast cancer using a 6 MV photon beam with two isocentric opposing tangential unwedged fields. Daily dose was 2.3 Gy at 95% isodose line given by two fields/day, 5 days/week. A total dose of 46 Gy was given in 20 fractions over a 4-week period. Pregnancy confirmed during the second therapeutic week. Treatment lasted between the second and sixth gestation week. Radiation dose to fetus was estimated from in vivo and phantom measurements using thermoluminescence dosimeters and an ionization chamber. In vivo measurements were performed by inserting either a catheter with TL dosimeters or ionization chamber into the patient's rectum. Phantom measurements were performed by simulating the treatment conditions on an anthropomorphic phantom. Results: TLD measurements (in vivo and phantom) revealed fetal dose to be 0.085% of the tumor dose, corresponding to a cumulative fetal dose of 3.9 cGy for the entire treatment of 46 Gy. Chamber measurements (in vivo and phantom) revealed a fetal dose less than the TLD result: 0.079 and 0.083% of the tumor dose corresponding to cumulative fetal dose of 3.6 cGy and 3.8 cGy for in vivo and phantom measurement, respectively. Conclusions: It was concluded that the cumulative dose delivered to the unshielded fetus was 3.9 cGy for a 46 Gy total tumor dose. The estimated fetal dose is low compared to the total tumor dose given due to the early stage of pregnancy, the large distance between fundus-radiation field, and the fact that no wedges and/or lead blocks were used. No deterministic biological effects of radiation on the live-born embryo are expected. The lifetime risk for radiation-induced fatal cancer is higher than the normal incidence, but is considered as inconsequential

  13. Experimental evaluation of a MOSFET dosimeter for proton dose measurements

    International Nuclear Information System (INIS)

    Kohno, Ryosuke; Nishio, Teiji; Miyagishi, Tomoko; Hirano, Eriko; Hotta, Kenji; Kawashima, Mitsuhiko; Ogino, Takashi

    2006-01-01

    The metal oxide semiconductor field-effect transistor (MOSFET) dosimeter has been widely studied for use as a dosimeter for patient dose verification. The major advantage of this detector is its size, which acts as a point dosimeter, and also its ease of use. The commercially available TN502RD MOSFET dosimeter manufactured by Thomson and Nielsen has never been used for proton dosimetry. Therefore we used the MOSFET dosimeter for the first time in proton dose measurements. In this study, the MOSFET dosimeter was irradiated with 190 MeV therapeutic proton beams. We experimentally evaluated dose reproducibility, linearity, fading effect, beam intensity dependence and angular dependence for the proton beam. Furthermore, the Bragg curve and spread-out Bragg peak were also measured and the linear-energy transfer (LET) dependence of the MOSFET response was investigated. Many characteristics of the MOSFET response for proton beams were the same as those for photon beams reported in previous papers. However, the angular MOSFET responses at 45, 90, 135, 225, 270 and 315 degrees for proton beams were over-responses of about 15%, and moreover the MOSFET response depended strongly on the LET of the proton beam. This study showed that the angular dependence and LET dependence of the MOSFET response must be considered very carefully for quantitative proton dose evaluations

  14. A Comparative Evaluation of Normal Tissue Doses for Patients Receiving Radiation Therapy for Hodgkin Lymphoma on the Childhood Cancer Survivor Study and Recent Children's Oncology Group Trials

    International Nuclear Information System (INIS)

    Zhou, Rachel; Ng, Angela; Constine, Louis S.; Stovall, Marilyn; Armstrong, Gregory T.; Neglia, Joseph P.; Friedman, Debra L.; Kelly, Kara; FitzGerald, Thomas J.; Hodgson, David C.

    2016-01-01

    Purpose: Survivors of pediatric Hodgkin lymphoma (HL) are recognized to have an increased risk of delayed adverse health outcomes related to radiation therapy (RT). However, the necessary latency required to observe these late effects means that the estimated risks apply to outdated treatments. We sought to compare the normal tissue dose received by children treated for HL and enrolled in the Childhood Cancer Survivor Study (CCSS) (diagnosed 1970-1986) with that of patients treated in recent Children's Oncology Group (COG) trials (enrolled 2002-2012). Methods and Materials: RT planning data were obtained for 50 HL survivors randomly sampled from the CCSS cohort and applied to computed tomography planning data sets to reconstruct the normal tissue dosimetry. For comparison, the normal tissue dosimetry data were obtained for all 191 patients with full computed tomography–based volumetric RT planning on COG protocols AHOD0031 and AHOD0831. Results: For early-stage patients, the mean female breast dose in the COG patients was on average 83.5% lower than that for CCSS patients, with an absolute reduction of 15.5 Gy. For advanced-stage patients, the mean breast dose was decreased on average by 70% (11.6 Gy average absolute dose reduction). The mean heart dose decreased on average by 22.9 Gy (68.6%) and 17.6 Gy (56.8%) for early- and advanced-stage patients, respectively. All dose comparisons for breast, heart, lung, and thyroid were significantly lower for patients in the COG trials than for the CCSS participants. Reductions in the prescribed dose were a major contributor to these dose reductions. Conclusions: These are the first data quantifying the significant reduction in the normal tissue dose using actual, rather than hypothetical, treatment plans for children with HL. These findings provide useful information when counseling families regarding the risks of contemporary RT.

  15. Evaluation of the repeated dose liver micronucleus assay using young adult rats with cyclophosphamide monohydrate: a report of a collaborative study by CSGMT/JEMS.MMS.

    Science.gov (United States)

    Matsumoto, Kazumi; Zaizen, Kazuyo; Miyamoto, Atsushi; Wako, Yumi; Kawasako, Kazufumi; Ishida, Hisao

    2015-03-01

    The repeated dose liver micronucleus (RDLMN) assay using young adult rats has the potential to detect liver carcinogens, and this assay could be integrated into general toxicological studies. In this study, in order to assess the performance of the assay, cyclophosphamide monohydrate (CP) was tested in a 14-day RDLMN assay. Based on the results of the 4-day repeated dose-finding study, 10 mg/kg/day of CP was selected as the highest dose and the lower doses were set at 5, 2.5, 1.25, and 0.625 mg/kg/day for the 14-day RDLMN assay. On the day after the completion of the dosing period, specimens of hepatocytes and bone marrow cells were prepared and the induction of micronuclei was assessed. No changes were observed in the incidences of micronucleated hepatocytes. Nevertheless, the incidences of micronucleated immature erythrocytes in the bone marrow were increased significantly at CP doses of 1.25 mg/kg/day or more. These findings are consistent with reports that CP induces tumors in various tissues but it does not induce liver tumors.

  16. Dose evaluation and protection of cosmic radiation

    International Nuclear Information System (INIS)

    Iwai, Satoshi; Takagi, Toshiharu

    2004-01-01

    This paper explained the effects of cosmic radiation on aircraft crews and astronauts, as well as related regulations. International Commission on Radiological Protection (ICRP) recommends the practice of radiation exposure management for the handling/storage of radon and materials containing natural radioactive substances, as well as for boarding jet aircraft and space flight. Common aircraft crew members are not subject to radiation exposure management in the USA and Japan. In the EU, the limit value is 6 mSv per year, and for the crew group exceeding this value, it is recommended to keep records containing appropriate medical examination results. Pregnant female crewmembers are required to keep an abdominal surface dose within 1 mSv. For astronauts, ICRP is in the stage of thinking about exposure management. In the USA, National Council on Radiation Protection and Measurement has set dose limits for 30 days, 1 year, and lifetime, and recommends lifetime effective dose limits against carcinogenic risk for each gender and age group. This is the setting of the dose limits so that the risk of carcinogenesis, to which space radiation exposure is considered to contribute, will reach 3%. For cosmic radiation environments at spacecraft inside and aircraft altitude, radiation doses can be calculated for astronauts and crew members, using the calculation methods for effective dose and dose equivalent for tissue. (A.O.)

  17. Prescribing and evaluating target dose in dose-painting treatment plans

    DEFF Research Database (Denmark)

    Håkansson, Katrin; Specht, Lena; Aznar, Marianne C

    2014-01-01

    BACKGROUND: Assessment of target dose conformity in multi-dose-level treatment plans is challenging due to inevitable over/underdosage at the border zone between dose levels. Here, we evaluate different target dose prescription planning aims and approaches to evaluate the relative merit of such p......-painting and multi-dose-level plans. The tool can be useful for quality assurance of multi-center trials, and for visualizing the development of treatment planning in routine clinical practice....... of such plans. A quality volume histogram (QVH) tool for history-based evaluation is proposed. MATERIAL AND METHODS: Twenty head and neck cancer dose-painting plans with five prescription levels were evaluated, as well as clinically delivered simultaneous integrated boost (SIB) plans from 2010 and 2012. The QVH...

  18. Collaborative work on evaluation of ovarian toxicity. 13) Two- or four-week repeated dose studies and fertility study of PPAR alpha/gamma dual agonist in female rats.

    Science.gov (United States)

    Sato, Norihiro; Uchida, Keisuke; Nakajima, Mikio; Watanabe, Atsushi; Kohira, Terutomo

    2009-01-01

    The main focus of this study was to determine the optimal dosing period in a repeated dose toxicity study based on toxic effects as assessed by ovarian morphological changes. To assess morphological and functional changes induced in the ovary by a peroxisome proliferator-activated receptor (PPAR) alpha/gamma dual agonist, the compound was administered to female rats at dose levels of 0, 4, 20, and 100 mg/kg/day in a repeated dose toxicity study for 2 or 4 weeks, and from 2 weeks prior to mating to Day 7 of pregnancy in a female fertility study. In the repeated dose toxicity study, an increase in atresia of large follicles, a decrease in corpora lutea, and an increase in stromal cells were observed in the treated groups. In addition, the granulosa cell exfoliations into antrum of large follicles and corpora lutea with retained oocyte are morphological characteristics induced by this compound, and they might be related with abnormal condition of ovulation. In the female fertility study, the pregnancy rate tended to decrease in the 100 mg/kg/day group. At necropsy, decreases in the number of corpora lutea, implantations and live embryos were noted in the 20 and 100 mg/kg/day group. No changes were observed in animals given 4 mg/kg/day. These findings indicated that histopathological changes in the ovary are important endpoints for evaluation of drugs inducing ovarian damage. In conclusion, a 2-week administration period is sufficient to detect ovarian toxicity of this test compound in the repeated dose toxicity study.

  19. Evaluation of the absorbed dose during studies of the renal function due to I123 / I131 (hippuran) and In111 (DTPA)

    International Nuclear Information System (INIS)

    Vasquez, M.; Castillo, C.; Sarachaga, R.; Rojas, R.; Zelada, L.; Melendez, J.; Gomez, M.; Diaz, E.

    2014-08-01

    Using the methodology MIRD and representation Cristy-Eckerman for kidneys, bladder, and whole body as organs of the bio-kinetics of I 123 / I 131 (hippuran) and the In 111 (D PTA), the absorbed dose for studies of the renal function of adults due to the I 123 is 0,0071 mGy/MBq where 88.16% corresponds to its auto-dose and 11,96% to the organs of their bio-kinetics; while for the I 131 their dose is 0,032 mGy/MBq where 95,03% corresponds to its auto-dose and 4,97% to the organs of their bio-kinetics. For the In 111 their dose is 0,0168 mGy/MBq where 71,68% corresponds to their auto-dose and 28,32% to the organs of their bio-kinetics. In all the cases the dosimetric contributions of the organs of the bio-kinetics (whole body and urinary bladder) are very significant, and this fundamentally is due to the photons of the whole body. (Author)

  20. Correct statistical evaluation for total dose in rural settlement

    International Nuclear Information System (INIS)

    Vlasova, N.G.; Skryabin, A.M.

    2001-01-01

    Statistical evaluation of dose reduced to the determination of an average value and its error. If an average value of a total dose in general can be determined by simple summarizing of the averages of its external and internal components, the evaluation of an error can be received only from its distribution. Herewith, considering that both components of the dose are interdependent, to summarize their distributions, as a last ones of a random independent variables, is incorrect. It follows that an evaluation of the parameters of the total dose distribution, including an error, in general, cannot be received empirically, particularly, at the lack or absence of the data on one of the components of the last one, that constantly is happens in practice. If the evaluation of an average for total dose was defined somehow, as the best, as an average of a distribution of the values of individual total doses, as summarizing the individual external and internal doses by the random type, that an error of evaluation had not been produced. The methodical approach to evaluation of the total dose distribution at the lack of dosimetric information was designed. The essence of it is original way of an interpolation of an external dose distribution, using data on an internal dose

  1. Evaluation of dose reduction versus standard dosing for maintenance of remission in patients with spondyloarthritis and clinical remission with anti-TNF (REDES-TNF): study protocol for a randomized controlled trial.

    Science.gov (United States)

    Pontes, Caridad; Gratacós, Jordi; Torres, Ferran; Avendaño, Cristina; Sanz, Jesús; Vallano, Antoni; Juanola, Xavier; de Miguel, Eugenio; Sanmartí, Raimon; Calvo, Gonzalo

    2015-08-20

    Dose reduction schedules of tumor necrosis factor antagonists (anti-TNF) as maintenance therapy in patients with spondyloarthritis are used empirically in clinical practice, despite the lack of clinical trials providing evidence for this practice. To address this issue the Spanish Society of Rheumatology (SER) and Spanish Society of Clinical Pharmacology (SEFC) designed a 3-year multicenter, randomized, open-label, controlled clinical trial (2 years for inclusion and 1 year of follow-up). The study is expected to include 190 patients with axial spondyloarthritis on stable maintenance treatment (≥4 months) with any anti-TNF agent at doses recommended in the summary of product characteristics. Patients will be randomized to either a dose reduction arm or maintenance of the dosing regimen as per the official labelling recommendations. Randomization will be stratified according to the anti-TNF agent received before study inclusion. Patient follow-up, visit schedule, and examinations will be maintained as per normal clinical practice recommendations according to SER guidelines. The study aims to test the hypothesis of noninferiority of the dose reduction strategy compared with standard treatment. The first patients were recruited in July 2012, and study completion is scheduled for the end of April 2015. The REDES-TNF study is a pragmatic clinical trial that aims to provide evidence to support a medical decision now made empirically. The study results may help inform clinical decisions relevant to both patients and healthcare decision makers. EudraCT 2011-005871-18 (21 December 2011).

  2. Relative bioequivalence evaluation of two oral atomoxetine hydrochloride capsules: a single dose, randomized, open-label, 2-period crossover study in healthy Chinese volunteers under fasting conditions.

    Science.gov (United States)

    Shang, D-W; Guo, W; Zhou, F-C; Wang, X-P; Li, A-N; Zhang, L; Li, W-B; Lu, W; Wang, C-Y

    2013-11-01

    To evaluate the bioequivalence of a new formulation of atomoxetine hydrochloride (CAS 82248-59-7) capsules (test) and an available branded capsules (reference) after administration of a single 40 mg dose, randomized, open-label, 2-period crossover study was conducted in 22 healthy male Chinese subjects with a 1-week wash-out period. This study was designed for/the Honglin Pharmaceutical Co. Ltd and contracted to be done by the Beijing Anding Hospital in order to satisfy Chinese regulatory requirements to allow marketing of this generic product and performed according to the criteria of SFDA. Blood samples were collected before and 0.25, 0.5, 1, 1.5, 2, 3, 4, 6, 9, 12, 16 and 24 h after drug administration. Plasma concentrations were determined by high-performance liquid chromatography (HPLC) with UV detection. A non-compartmental method was used to calculate the pharmacokinetic parameters and evaluate bioequivalence of the 2 formulations. The 90% confidence interval (CI) of the ratios (test/reference) of atomoxetine for AUC0-24, AUC0-∞ and Cmax were 100.9% (93.6-108.8%), 103.1% (95.1-111.7%) and 105.2% (92.8-119.4%), respectively, which fell within the interval of 80-125% and 75-133%. No clinically significant changes or abnormalities were noted in laboratory data and vital signs. From these results it can be concluded that the test formulation of atomoxetine capsules met the regulatory criterion for bioequivalence to the reference formulation. © Georg Thieme Verlag KG Stuttgart · New York.

  3. Evaluation of shipping doses and compositions for vitrified waste

    International Nuclear Information System (INIS)

    Shapiro, A.

    1996-01-01

    Shipments of radioactive materials must adhere to dose limits specified in the Code of Federal Regulations. This paper discusses methods for evaluating shipping doses of vitrified waste. A methodology was developed for evaluating the change in vitrification composition required to maintain shipping dose rates within limits. The point kernel codes QAD and Microshield were used to evaluate dose equivalent rates from specified waste forms and radioactivity measurements. The Origen code was utilized to provide the gamma-ray activity as a function of time from isotopic activity measurements. This gamma-ray activity served as source input for QAD. Microshield developed its own source from the given isotopic activities

  4. Retrospective study evaluating dose standards for infliximab in patients with rheumatoid arthritis at Hospital Israelita Albert Einstein, São Paulo, Brazil.

    Science.gov (United States)

    Scheinberg, Morton; Goldenberg, José; Feldman, Daniel P; Nóbrega, João Luiz

    2008-08-01

    We determined, in our surrounding environment, the proportion of patients being treated with infliximab who required a therapeutic scheme escalation (an infliximab dose increase surpassing the level of 3 mg/kg every 8 weeks and/or a decrease on the current between infusions' interval). This was a study of the retrospective analysis of data from the 41 rheumatoid arthritis (RA) patients receiving an infliximab therapy at the Albert Einstein Israelita Hospital, from January 2001 up to December 2005. A questionnaire was applied to these patients, assessing their clinical and laboratory data, adverse events, and individual information regarding the infliximab administration. Therapeutic dose information was available in 68% (28/41) of the RA patients, with 46% of these (13/28) receiving a dose increase, and 30% (8/27) experiencing a shortening of the between infusions' interval. The average final infliximab dose (4.21 mg/kg) was significantly greater than their average initial dose (3.29 mg/kg). The average time intervals between the initial and final infusions, though shortened, were not significantly different. A proportion of 73% (30/41) of these patients demonstrated improvement in at least one of the assessed clinical parameters, and 50% of these patients (15/30) experienced a dose increase, while 20% (6/30) experienced shortening of the between treatments' interval. A total of 20% (8/41) of the original patients experienced adverse events. Although infliximab is effective in the control of RA, dose adjustment and/or shortening of the between treatments' interval is frequently required.

  5. Measurement and evaluation of internal dose

    International Nuclear Information System (INIS)

    Lee, Tae Young; Chang, S. Y.; Lee, J. I.; Song, M. Y.

    2006-01-01

    This report describes the contents and results for implementation of internal radiation monitoring programme, measurement of uranium present in lung by lung counter and assessment of committed effective dose for radiation workers of the KNFC. The aim of radiation protection was achieved by implementing this activity

  6. Critical commentary on dose-rate evaluations

    International Nuclear Information System (INIS)

    Dowdy, E.J.; Malenfant, R.E.; Plassmann, E.A.

    1984-01-01

    Survivors of Hiroshima and Nagasaki present a unique problem in dosimetry: the effects of radiation exposure may be inferred although the exposure itself is unknown. Experience with a replica of Little Boy demonstrates the difficulties of measuring dose rates, the problems of comparing measurements with calculations, and the inadequacy of the conventional standards that are used to calibrate dosimeters

  7. 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

  8. Evaluation of various approaches for assessing dose indicators and patient organ doses resulting from radiotherapy cone-beam CT

    International Nuclear Information System (INIS)

    Rampado, Osvaldo; Giglioli, Francesca Romana; Rossetti, Veronica; Ropolo, Roberto; Fiandra, Christian; Ragona, Riccardo

    2016-01-01

    Purpose: The aim of this study was to evaluate various approaches for assessing patient organ doses resulting from radiotherapy cone-beam CT (CBCT), by the use of thermoluminescent dosimeter (TLD) measurements in anthropomorphic phantoms, a Monte Carlo based dose calculation software, and different dose indicators as presently defined. Methods: Dose evaluations were performed on a CBCT Elekta XVI (Elekta, Crawley, UK) for different protocols and anatomical regions. The first part of the study focuses on using PCXMC software (PCXMC 2.0, STUK, Helsinki, Finland) for calculating organ doses, adapting the input parameters to simulate the exposure geometry, and beam dose distribution in an appropriate way. The calculated doses were compared to readouts of TLDs placed in an anthropomorphic Rando phantom. After this validation, the software was used for analyzing organ dose variability associated with patients’ differences in size and gender. At the same time, various dose indicators were evaluated: kerma area product (KAP), cumulative air-kerma at the isocenter (K_a_i_r), cone-beam dose index, and central cumulative dose. The latter was evaluated in a single phantom and in a stack of three adjacent computed tomography dose index phantoms. Based on the different dose indicators, a set of coefficients was calculated to estimate organ doses for a range of patient morphologies, using their equivalent diameters. Results: Maximum organ doses were about 1 mGy for head and neck and 25 mGy for chest and pelvis protocols. The differences between PCXMC and TLDs doses were generally below 10% for organs within the field of view and approximately 15% for organs at the boundaries of the radiation beam. When considering patient size and gender variability, differences in organ doses up to 40% were observed especially in the pelvic region; for the organs in the thorax, the maximum differences ranged between 20% and 30%. Phantom dose indexes provided better correlation with organ doses

  9. Dose Evaluation of Fractionated Schema and Distance From Tumor to Spinal Cord for Spinal SBRT with Simultaneous Integrated Boost: A Preliminary Study.

    Science.gov (United States)

    Yang, Hao; Cai, Bo-ning; Wang, Xiao-shen; Cong, Xiao-hu; Xu, Wei; Wang, Jin-yuan; Yang, Jun; Xu, Shou-ping; Ju, Zhong-jian; Ma, Lin

    2016-02-23

    BACKGROUND This study investigated and quantified the dosimetric impact of the distance from the tumor to the spinal cord and fractionation schemes for patients who received stereotactic body radiation therapy (SBRT) and hypofractionated simultaneous integrated boost (HF-SIB). MATERIAL AND METHODS Six modified planning target volumes (PTVs) for 5 patients with spinal metastases were created by artificial uniform extension in the region of PTV adjacent spinal cord with a specified minimum tumor to cord distance (0-5 mm). The prescription dose (biologic equivalent dose, BED) was 70 Gy in different fractionation schemes (1, 3, 5, and 10 fractions). For PTV V100, Dmin, D98, D95, and D1, spinal cord dose, conformity index (CI), V30 were measured and compared. RESULTS PTV-to-cord distance influenced PTV V100, Dmin, D98, and D95, and fractionation schemes influenced Dmin and D98, with a significant difference. Distances of ≥2 mm, ≥1 mm, ≥1 mm, and ≥0 mm from PTV to spinal cord meet dose requirements in 1, 3, 5, and 10 fractionations, respectively. Spinal cord dose, CI, and V30 were not impacted by PTV-to-cord distance and fractionation schemes. CONCLUSIONS Target volume coverage, Dmin, D98, and D95 were directly correlated with distance from the spinal cord for spine SBRT and HF-SIB. Based on our study, ≥2 mm, ≥1 mm, ≥1 mm, and ≥0 mm distance from PTV to spinal cord meets dose requirements in 1, 3, 5 and 10 fractionations, respectively.

  10. An evaluation of high-dose jobs for ALARA improvement

    International Nuclear Information System (INIS)

    Mun, J. H.; Kim, H. S.

    1997-01-01

    It is well known that about 70 percent of occupational dose have incurred from maintenance jobs at outage period. To reduce occupational dose, first, the high-dose jobs at the outage period should be identified and evaluated. For this, the database program is used, which contains the ORE data of reference plants, Kori Units 3 and 4. As a result, it is found that the jobs related to steam generator are the highest dose jobs in terms of collective ORE dose. From the analysis of the job procedures of those jobs, the ALARA improvements are also derived

  11. Multicentre evaluation of a novel vaginal dose reporting method in 153 cervical cancer patients

    DEFF Research Database (Denmark)

    Westerveld, Henrike; de Leeuw, Astrid; Kirchheiner, Kathrin

    2016-01-01

    Background and purpose Recently, a vaginal dose reporting method for combined EBRT and BT in cervical cancer patients was proposed. The current study was to evaluate vaginal doses with this method in a multicentre setting, wherein different applicators, dose rates and protocols were used. Materia...

  12. Evaluation of the sterility of single-dose medications used in a multiple-dose fashion.

    Science.gov (United States)

    Martin, Elizabeth P; Mukherjee, Jean; Sharp, Claire R; Sinnott-Stutzman, Virginia B

    2017-11-01

    Bacterial proliferation was evaluated in single-dose medications used in a multi-dose fashion and when medications were intentionally inoculated with bacteria. Of 5 experimentally punctured medications, 1 of 75 vials (50% dextrose) became contaminated. When intentionally inoculated, hydroxyethyl starch and heparinized saline supported microbial growth. Based on these findings, it is recommended that hydroxyethyl starch and heparinized saline not be used in a multi-dose fashion.

  13. Robust ray-tracing algorithms for interactive dose rate evaluation

    International Nuclear Information System (INIS)

    Perrotte, L.

    2011-01-01

    More than ever, it is essential today to develop simulation tools to rapidly evaluate the dose rate received by operators working on nuclear sites. In order to easily study numerous different scenarios of intervention, computation times of available softwares have to be all lowered. This mainly implies to accelerate the geometrical computations needed for the dose rate evaluation. These computations consist in finding and sorting the whole list of intersections between a big 3D scene and multiple groups of 'radiative' rays meeting at the point where the dose has to be measured. In order to perform all these computations in less than a second, we first propose a GPU algorithm that enables the efficient management of one big group of coherent rays. Then we present a modification of this algorithm that guarantees the robustness of the ray-triangle intersection tests through the elimination of the precision issues due to floating-point arithmetic. This modification does not require the definition of scene-dependent coefficients ('epsilon' style) and only implies a small loss of performance (less than 10%). Finally we propose an efficient strategy to handle multiple ray groups (corresponding to multiple radiative objects) which use the previous results.Thanks to these improvements, we are able to perform an interactive and robust dose rate evaluation on big 3D scenes: all of the intersections (more than 13 million) between 700 000 triangles and 12 groups of 100 000 rays each are found, sorted along each ray and transferred to the CPU in 470 milliseconds. (author) [fr

  14. A biosafety evaluation of synchrotron radiation X-ray to skin and bone marrow: single dose irradiation study of rats and macaques.

    Science.gov (United States)

    Lu, Yifan; Tang, Guanghui; Lin, Hui; Lin, Xiaojie; Jiang, Lu; Yang, Guo-Yuan; Wang, Yongting

    2017-06-01

    Very limited experimental data is available regarding the safe dosages related to synchrotron radiation (SR) procedures. We used young rats and macaques to address bone marrow and skin tolerance to various doses of synchrotron radiation. Rats were subjected to 0, 0.5, 2.5, 5, 25 or 100 Gy local SR X-ray irradiation at left hind limb. Rat blood samples were analyzed at 2-90 days after irradiation. The SR X-ray irradiated skin and tibia were sectioned for morphological examination. For non-human primate study, three male macaques were subjected to 0.5 or 2.5 Gy SR X-ray on crus. Skin responses of macaques were observed. All rats that received SR X-ray irradiation doses greater than 2.5 Gy experienced hair loss and bone-growth inhibition, which were accompanied by decreased number of follicles, thickened epidermal layer, and decreased density of bone marrow cells (p X-ray but showed significant hair loss when the dose was raised above 2.5 Gy. The safety threshold doses of SR X-ray for rat skin, bone marrow and macaque skin are between 0.5 and 2.5 Gy. Our study provided essential information regarding the biosafety of SR X-ray irradiation.

  15. Dose rate and dose fractionation studies in total body irradiation of dogs

    International Nuclear Information System (INIS)

    Kolb, H.J.; Netzel, B.; Schaffer, E.; Kolb, H.

    1979-01-01

    Total body irradiation (TBI) with 800-900 rads and allogeneic bone marrow transplantation according to the regimen designated by the Seattle group has induced remissions in patients with otherwise refractory acute leukemias. Relapse of leukemia after bone marrow transplantation remains the major problem, when the Seattle set up of two opposing 60 Co-sources and a low dose rate is used in TBI. Studies in dogs with TBI at various dose rates confirmed observations in mice that gastrointestinal toxicity is unlike toxicity against hemopoietic stem cells and possibly also leukemic stem cells depending on the dose rate. However, following very high single doses (2400 R) and marrow infusion acute gastrointestinal toxicity was not prevented by the lowest dose rate studied (0.5 R/min). Fractionated TBI with fractions of 600 R in addition to 1200 R (1000 rads) permitted the application of total doses up to 300 R followed by marrow infusion without irreversible toxicity. 26 dogs given 2400-3000 R have been observed for presently up to 2 years with regard to delayed radiation toxicity. This toxicity was mild in dogs given single doses at a low dose rate or fractionated TBI. Fractionated TBI is presently evaluated with allogeneic transplants in the dog before being applied to leukemic patients

  16. Dose Evaluation and Quality Criteria in Dental Radiology

    International Nuclear Information System (INIS)

    Gori, C.; Rossi, F.; Stecco, A.; Villari, N.; Zatelli, G.

    2000-01-01

    Radioprotection in dental radiology is of particular interest in the framework of the Revised Medical Exposure Directive for the great number of examinations involving the adult as well as the paediatric population (Article 9: Special Practice). The present study is intended to find the quality criteria of orthodontic imaging and for evaluating the dose absorbed within the dental and maxillary volume in connection with radiological examinations performed with either spiral CT, dental panoramic tomography or teleradiography. The X ray dose to organs sited in the body, neck, ocular and intracranial area was measured using lithium fluoride dosemeters, positioned in a Rando phantom. Quality criteria have been established by an expert radiologist considering the diagnostic information obtained in the images. The dosimetric data obtained were comparable with other authors', although with some differences due to technical characteristics. These result data are useful for choosing the patient's diagnostic path, considering the radiobiological risk associated with increasing orthodontic imaging. (author)

  17. Evaluating the maximum patient radiation dose in cardiac interventional procedures

    International Nuclear Information System (INIS)

    Kato, M.; Chida, K.; Sato, T.; Oosaka, H.; Tosa, T.; Kadowaki, K.

    2011-01-01

    Many of the X-ray systems that are used for cardiac interventional radiology provide no way to evaluate the patient maximum skin dose (MSD). The authors report a new method for evaluating the MSD by using the cumulative patient entrance skin dose (ESD), which includes a back-scatter factor and the number of cine-angiography frames during percutaneous coronary intervention (PCI). Four hundred consecutive PCI patients (315 men and 85 women) were studied. The correlation between the cumulative ESD and number of cine-angiography frames was investigated. The irradiation and overlapping fields were verified using dose-mapping software. A good correlation was found between the cumulative ESD and the number of cine-angiography frames. The MSD could be estimated using the proportion of cine-angiography frames used for the main angle of view relative to the total number of cine-angiography frames and multiplying this by the cumulative ESD. The average MSD (3.0±1.9 Gy) was lower than the average cumulative ESD (4.6±2.6 Gy). This method is an easy way to estimate the MSD during PCI. (authors)

  18. A randomised controlled trial evaluating IGF1 titration in contrast to current GH dosing strategies in children born small for gestational age: the North European Small-for-Gestational-Age Study.

    Science.gov (United States)

    Jensen, Rikke Beck; Thankamony, Ajay; O'Connell, Susan M; Kirk, Jeremy; Donaldson, Malcolm; Ivarsson, Sten-A; Söder, Olle; Roche, Edna; Hoey, Hilary; Dunger, David B; Juul, Anders

    2014-10-01

    Short children born small for gestational age (SGA) are treated with a GH dose based on body size, but treatment may lead to high levels of IGF1. The objective was to evaluate IGF1 titration of GH dose in contrast to current dosing strategies. In the North European Small-for-Gestational-Age Study (NESGAS), 92 short pre-pubertal children born SGA were randomised after 1 year of high-dose GH treatment (67 μg/kg per day) to three different regimens: high dose (67 μg/kg per day), low dose (35 μg/kg per day) or IGF1 titration. The average dose during the second year of the randomised trial did not differ between the IGF1 titration group (38 μg/kg per day, s.d. 0.019) and the low-dose group (35 μg/kg per day, s.d. 0.002; P=0.46), but there was a wide variation in the IGF1 titration group (range 10-80 μg/kg per day). The IGF1 titration group had significantly lower height gain (0.17 SDS, s.d. 0.18) during the second year of the randomised trial compared with the high-dose group (0.46 SDS, s.d. 0.25), but not significantly lower than the low-dose group (0.23 SDS, s.d. 0.15; P=0.17). The IGF1 titration group had lower IGF1 levels after 2 years of the trial (mean 1.16, s.d. 1.24) compared with both the low-dose (mean 1.76, s.d. 1.48) and the high-dose (mean 2.97, s.d. 1.63) groups. IGF1 titration of GH dose in SGA children proved less effective than current dosing strategies. IGF1 titration resulted in physiological IGF1 levels with a wide range of GH dose and a poorer growth response, which indicates the role of IGF1 resistance and highlights the heterogeneity of short SGA children. © 2014 European Society of Endocrinology.

  19. Evaluation of a low-dose neonatal chest radiographic system

    International Nuclear Information System (INIS)

    Burton, E.M.; Kirks, D.R.; Strife, J.L.; Henry, G.C.; Kereiakes, J.G.

    1988-01-01

    A new low-dose chest radiographic system for use in the neonatal nursery was evaluated. This test system, composed of a Du Pont Kevlar fiber-front cassette, Quanta fast-detail screen, Cronex 4L film (wide latitude), and additional yttrium filtration (0.1 mm), reduced the radiation dose in neonatal chest radiography by 69% (0.9 vs 2.9 mrad [0.009 vs 0.029 mGy]) as compared with a conventional system without added yttrium filtration; the thyroid dose was reduced by 76% (0.9 vs 3.7 mrad [0.009 vs 0.037 mGy]). The cumulative dose reduction was achieved through a combination of factors, including (1) beam hardening by the added yttrium filter, (2) increased X-ray transmission through the Kevlar cassette, and (3) a fast film-screen combination. Scatter radiation at distances of 1 and 6 ft. (0.3 and 1.8 m) was negligible for both systems. Image sharpness was compared for the conventional system with and without added yttrium filtration and for the Kevlar system with yttrium. Although sharpness of bony detail was unchanged by adding yttrium filtration to the conventional system, a decrease in sharpness was noted with the Kevlar system. Because image sharpness was affected in the test system, we are not using the Kevlar-Cronex 4L system for mobile chest radiography in the neonatal intensive care unit, despite dose reductions. However, further study is recommended to determine if there is a slower film-screen combination with yttrium filtration that will not degrade image sharpness

  20. Evaluation of the absorbed dose in odontological computerized tomography

    International Nuclear Information System (INIS)

    Legnani, Adriano; Schelin, Hugo R.; Rocha, Anna Silvia P.S. da; Khoury, Helen J.

    2011-01-01

    This paper evaluated the absorbed dose at the surface entry known as 'cone beam computed tomography' (CBCT) in odontological computerized tomography. Examination were simulated with CBCT for measurements of dose. A phantom were filled with water, becoming scatter object of radiation. Thermoluminescent dosemeters were positioned on points correspondent to eyes and salivary glands

  1. Absorbed dose evaluations in retrospective dosimetry: Methodological developments using quartz

    DEFF Research Database (Denmark)

    Bailiff, I.K.; Bøtter-Jensen, L.; Correcher, V.

    2000-01-01

    Dose evaluation procedures based on luminescence techniques were applied to 50 quartz samples extracted from bricks that had been obtained from populated or partly populated settlements in Russia and Ukraine downwind of the Chernobyl NPP. Determinations of accrued dose in the range similar to 30...

  2. Evaluation of radiation doses delivered in different chest CT protocols

    International Nuclear Information System (INIS)

    Gorycki, Tomasz; Lasek, Iwona; Kamiński, Kamil; Studniarek, Michał

    2014-01-01

    There are differences in the reference diagnostic levels for the computed tomography (CT) of the chest as cited in different literature sources. The doses are expressed either in weighted CT dose index (CTDI VOL ) used to express the dose per slice, dose-length product (DLP), and effective dose (E). The purpose of this study was to assess the radiation dose used in Low Dose Computer Tomography (LDCT) of the chest in comparison with routine chest CT examinations as well as to compare doses delivered in low dose chest CT with chest X-ray doses. CTDI VOL and DLP doses were taken to analysis from routine CT chest examinations (64 MDCT TK LIGHT SPEED GE Medical System) performed in 202 adult patients with FBP reconstruction: 51 low dose, 106 helical, 20 angio CT, and 25 high resolution CT protocols, as well as 19 helical protocols with iterative ASIR reconstruction. The analysis of chest X-ray doses was made on the basis of reports from 44 examinations. Mean values of CTDI VOL and DLP were, respectively: 2.1 mGy and 85.1 mGy·cm, for low dose, 9.7 mGy and 392.3 mGy·cm for helical, 18.2 mGy and 813.9 mGy·cm for angio CT, 2.3 mGy and 64.4 mGy·cm for high resolution CT, 8.9 mGy. and 317.6 mGy·cm for helical ASIR protocols. Significantly lower CTDI VOL and DLP values were observed for low dose and high resolution CT versus the remaining CT protocols; doses delivered in CT ASIR protocols were also lower (80–81%). The ratio between medial doses in low dose CT and chest X-ray was 11.56. Radiation dose in extended chest LDCT with parameters allowing for identification of mediastinal structures and adrenal glands is still much lower than that in standard CT protocols. Effective doses predicted for LDCT may exceed those used in chest X-ray examinations by a factor of 4 to 12, depending on LDCT scan parameters. Our results, as well as results from other authors, suggest a possibility of reducing the dose by means of iterative reconstruction. Efforts towards further dose

  3. Dose intercomparison studies for standardization of high-dose dosimetry in Viet Nam

    International Nuclear Information System (INIS)

    Mai Hoang Hoa; Duong Nguyen Dinh; Kojima, T.

    1999-01-01

    The Irradiation Center of the Vietnam Atomic Energy Commission (IC-VAEC) is planning to establish a traceability system for high-dose dosimetry and to provide high-dose standards as a secondary standard dosimetry laboratory (SSDL) level in Vietnam. For countries which do not have a standard dosimetry laboratory, the participation in the International Dose Assurance Service (IDAS) operated by the International Atomic Energy Agency (IAEA) is the most common means to verify own dosimetry performance with a certain uncertainty. This is, however, only one-direction dose intercomparison with evaluation by IAEA including unknown parameter at participant laboratories. The SSDL level laboratory should have traceability as well as compatibility, ability to evaluate uncertainties of its own dosimetry performance by itself In the present paper, we reviewed our dosimetry performance through two-way dose intercomparison studies and self-evaluation of uncertainty in our dosimetry procedure. The performance of silver dichromate dosimeter as reference transfer dosimeter in IC-VAEC was studied through two-way blind dose intercomparison experiments between the IC-VAEC and JAERI. As another channel of dose intercomparison with IAEA, alanine dosimeters issued by IDAS were simultaneously irradiated with the IC-VAEC dichromate dosimeters at IC-VAEC and analyzed by IAEA. Dose intercomparison between IC-VAEC and JAERI results into a good agreement (better than ±2.5%), and IDAS results also show similar agreement within ±3.0%. The uncertainty was self-estimated on the basis of the JAERI alanine dosimetry, and a preliminary value of about 1.86% at a 68% confidence level is established. The results from these intercomparisons and our estimation of the uncertainty are consistent. We hope that our experience is valuable to other countries which do not have dosimetry standard laboratories and/or are planning to establish them. (author)

  4. Design and development of an anthropomorphic phantom equipped with detectors in order to evaluate the effective dose E at workplaces: feasibility study; Conception et developpement d'un fantome anthropomorphe equipe de detecteurs dans le but d'evaluer la dose efficace a un poste de travail: etude de faisabilite

    Energy Technology Data Exchange (ETDEWEB)

    Furstoss, Ch

    2006-11-15

    My PhD study aims to determine the feasibility to design and develop, for photon fields, an anthropomorphic phantom equipped with detectors in order to evaluate the effective dose E at workplaces. First of all, the energy losses within the organs are calculated using the M.C.N.P.X. Monte Carlo code, in order to determine the detection positions within the different organs. Then, to decrease the number of detection positions, the organ contribution to the effective dose is studied. Finally, the characteristics of the detectors to insert and the characteristics of the phantom to use are deduced. The results show that 24 or 23 detection positions, according to the wT values (publication 60 or new recommendations of the ICRP), give a E estimation with an uncertainty of {+-}15 % from 50 keV to 4 MeV. Moreover, the interest of such an instrument is underlined while comparing the E estimation by the personal dose equivalent Hp to the E estimation by the instrumented phantom when the phantom is irradiated by point sources (worker in front of a glove box for example). Last, after the detector and phantom characteristic determination, two types of detectors and one type of phantom are selected. However, for the detectors mainly, developments are necessary. Follow up this study, the characterization and the adaptation of the detectors to the project would be interesting. Furthermore, the study to mixed photon-neutrons would be required the needs of the radiological protection community. (author)

  5. Evaluation of efficacy and safety of fixed dose lovastatin and niacinER combination in Asian Indian dyslipidemic patients: a multicentric study

    Directory of Open Access Journals (Sweden)

    Manoj Sharma

    2006-03-01

    Full Text Available Manoj Sharma1, Deepika R Sharma1, Vikram Singh1, RB Panwar2, HS Hira3, Bishav Mohan4, Naveen Kumar4, SK Sharma5, Rajeev Gupta61Clinical Research Division, Panacea-Biotec Ltd, New Delhi; 2SP Medical College, Bikaner; 3Maulana Azad Medical College, New Delhi; 4Dayanand Medical College, Ludhiana; 5SMS Medical College, Jaipur; 6Monilek Hospital and Research Center, Jaipur, India.Abstract: Asian Indian dyslipidemia is characterized by: borderline high low-density lipoprotein (LDL cholesterol and apolipoprotein (apo B; high triglycerides, low high-density lipoprotein (HDL cholesterol and apoA1; and high lipoprotein(a (lp[a]. We performed a controlled multicentric trial in India to evaluate the efficacy and safety of a fixed dose combination of lovastatin and niacin extended release (niacinER formulation in patients with moderate to severe dyslipidemia. Consecutive subjects that satisfied the selection criteria, agreed to an informed consent, and with no baseline presence of liver/renal disease or heart failure were enrolled in the study. After a 4-week run-in period there were 142 patients with LDL levels ≥ 130 mg/dL. Eleven patients were excluded because of uncontrolled hyperglycemia and 131 patients were recruited. After baseline evaluation of clinical and biochemical parameters all subjects were administered lovastatin (20 mg and niacinER (500 mg combination once daily. Dose escalation was done on basis of lipid parameters at 8 weeks and in 11 patients increased to lovastatin (20 mg and niacinER (1000 mg. An intention-to-treat analysis was performed and data was analyzed using nonparametric Wilcoxon signed rank test. Thirteen patients (10% were lost to follow-up and 4 (3% withdrew because of dermatological adverse effects: flushing, pruritus, and rash. The mean values of various lipid parameters (mg/dL at baseline, and at weeks 4, 12, and 24 respectively were: total cholesterol 233.9 ± 27, 206.3 ± 27, 189.8 ± 31, and 174.9 ± 27 mg/dL; LDL

  6. Radiation dose of CT coronary angiography in clinical practice: Objective evaluation of strategies for dose optimization

    International Nuclear Information System (INIS)

    Yerramasu, Ajay; Venuraju, Shreenidhi; Atwal, Satvir; Goodman, Dennis; Lipkin, David; Lahiri, Avijit

    2012-01-01

    Background: CT coronary angiography (CTCA) is an evolving modality for the diagnosis of coronary artery disease. Radiation burden associated with CTCA has been a major concern in the wider application of this technique. It is important to reduce the radiation dose without compromising the image quality. Objectives: To estimate the radiation dose of CTCA in clinical practice and evaluate the effect of dose-saving algorithms on radiation dose and image quality. Methods: Effective radiation dose was measured from the dose-length product in 616 consecutive patients (mean age 58 ± 12 years; 70% males) who underwent clinically indicated CTCA at our institution over 1 year. Image quality was assessed subjectively using a 4-point scale and objectively by measuring the signal- and contrast-to-noise ratios in the coronary arteries. Multivariate linear regression analysis was used to identify factors independently associated with radiation dose. Results: Mean effective radiation dose of CTCA was 6.6 ± 3.3 mSv. Radiation dose was significantly reduced by dose saving algorithms such as 100 kV imaging (−47%; 95% CI, −44% to −50%), prospective gating (−35%; 95% CI, −29% to −40%) and ECG controlled tube current modulation (−23%; 95% CI, −9% to −34%). None of the dose saving algorithms were associated with a significant reduction in mean image quality or the frequency of diagnostic scans (P = non-significant for all comparisons). Conclusion: Careful application of radiation-dose saving algorithms in appropriately selected patients can reduce the radiation burden of CTCA significantly, without compromising the image quality.

  7. [Evaluation of methods to calculate dialysis dose in daily hemodialysis].

    Science.gov (United States)

    Maduell, F; Gutiérrez, E; Navarro, V; Torregrosa, E; Martínez, A; Rius, A

    2003-01-01

    Daily dialysis has shown excellent clinical results because a higher frequency of dialysis is more physiological. Different methods have been described to calculate dialysis dose which take into consideration change in frequency. The aim of this study was to calculate all dialysis dose possibilities and evaluate the better and practical options. Eight patients, 6 males and 2 females, on standard 4 to 5 hours thrice weekly on-line hemodiafiltration (S-OL-HDF) were switched to daily on-line hemodiafiltration (D-OL-HDF) 2 to 2.5 hours six times per week. Dialysis parameters were identical during both periods and only frequency and dialysis time of each session were changed. Time average concentration (TAC), time average deviation (TAD), normalized protein catabolic rate (nPCR), Kt/V, equilibrated Kt/V (eKt/V), equivalent renal urea clearance (EKR), standard Kt/V (stdKt/V), urea reduction ratio (URR), hemodialysis product and time off dialysis were measured. Daily on-line hemodiafiltration was well accepted and tolerated. Patients maintained the same TAC although TAD decreased from 9.7 +/- 2 in baseline to a 6.2 +/- 2 mg/dl after six months, p time off dialysis was reduced to half. Dialysis frequency is an important urea kinetic parameter which there are to take in consideration. It's necessary to use EKR, stdKt/V or weekly URR to calculate dialysis dose for an adequate comparison between different frequency dialysis schedules.

  8. A Phase Ib dose-escalation study to evaluate safety and tolerability of the addition of the aminopeptidase inhibitor tosedostat (CHR-2797) to paclitaxel in patients with advanced solid tumours

    NARCIS (Netherlands)

    C.M.L. Herpen (Carla); F.A.L.M. Eskens (Ferry); M.J.A. de Jonge (Maja); I.M.E. Desar (Ingrid); L. Hooftman (Leon); E. Bone (Elisabeth); J.N.H. Timmerbonte (Johanna); J. Verweij (Jaap)

    2010-01-01

    textabstractBackground: This Phase Ib dose-escalating study investigated safety, maximum tolerated dose (MTD), dose-limiting toxicity (DLT), pharmacokinetics (PK) and clinical antitumour activity of tosedostat (CHR-2797), an orally bioavailable aminopeptidase inhibitor, in combination with

  9. A Phase Ib dose-escalation study to evaluate safety and tolerability of the addition of the aminopeptidase inhibitor tosedostat (CHR-2797) to paclitaxel in patients with advanced solid tumours.

    NARCIS (Netherlands)

    Herpen, C.M.L. van; Eskens, F.A.; Jonge, M. de; Desar, I.M.E.; Hooftman, L.; Bone, E.A.; Timmer-Bonte, J.N.H.; Verweij, J.

    2010-01-01

    BACKGROUND: This Phase Ib dose-escalating study investigated safety, maximum tolerated dose (MTD), dose-limiting toxicity (DLT), pharmacokinetics (PK) and clinical antitumour activity of tosedostat (CHR-2797), an orally bioavailable aminopeptidase inhibitor, in combination with paclitaxel. METHODS:

  10. Study of the heterogeneity effects of lung in the evaluation of absorbed dose in radiotherapy; Estudo dos efeitos da heterogeneidade de pulmao na avaliacao da dose absorvida em radioterapia

    Energy Technology Data Exchange (ETDEWEB)

    Campos, Luciana Tourinho

    2006-02-15

    The main objective of radiotherapy is to deliver the highest possible dose to the tumour, in order to destroy it, reducing as much as possible the doses to healthy tissues adjacent to the target volume. Therefore, it is necessary to do a planning of the treatment. The more complex is the treatment, the more difficult the planning will be, demanding computation sophisticated methods in its execution, in order to consider the heterogeneities present in the human body. Additionally, with the appearing of new radiotherapeutic techniques, that used irradiation fields of small area, for instance, the intensity modulated radiotherapy, the difficulties for the execution of a reliable treatment planning, became still larger. In this work it was studied the influence of the lung heterogeneity in the planning of the curves of percentage depth dose, PDP, obtained with the Eclipse{sup R} planning system for different sizes of irradiation fields, using the correction algorithms for heterogeneities available in the planning system: modified Batho, general Batho and equivalent tissue-air ratio. A thorax phantom, manufactured in acrylic, containing a region made of cork to simulate the lung tissue, was used. The PDP curves generated by the planning system were compared to those obtained by Monte Carlo simulation and with the use of thermoluminescent, TL, dosimetry. It was verified that the algorithms used by the Eclipse{sup R} system for the correction of heterogeneity effects are not able to generate correct results for PDP curves in the case of small fields, occurring differences of up to 100%, when the 1x1 cm{sup 2} treatment field is considered. These differences can cause a considerable subdosage in the lung tissue, reducing the possibility of the patient cure. (author)

  11. Radiation dose measurement in gastrointestinal studies

    International Nuclear Information System (INIS)

    Sulieman, A.; Elzaki, M.; Kappas, C.; Theodorou, K.

    2011-01-01

    Barium studies investigations (barium swallow, barium meal and barium enema) are the basic routine radiological examination, where barium sulphate suspension is introduced to enhance image contrast of gastrointestinal tracts. The aim of this study was to quantify the patients' radiation doses during barium studies and to estimate the organ equivalent dose and effective dose with those procedures. A total of 33 investigations of barium studies were measured by using thermoluminescence dosemeters. The result showed that the patient entrance surface doses were 12.6±10, 44.5±49 and 35.7±50 mGy for barium swallow, barium meal, follow through and enema, respectively. Effective doses were 0.2, 0.35 and 1.4 mSv per procedure for barium swallow, meal and enema respectively. Radiation doses were comparable with the previous studies. A written protocol for each procedure will reduce the inter-operator variations and will help to reduce unnecessary exposure. (authors)

  12. External contamination and skin dose. From ICRP and regulations to skin dose evaluation in practice

    International Nuclear Information System (INIS)

    Le Coulteulx, I.; Apretna, D.; Beaugerie, M.; Fenolland, J.; Frey, R.; Gonin, M.; Landry, B.; Laporte, E.; Le Guen, B.; Leval, D.

    2006-01-01

    Dose limitation to the skin is an objective of radiation protection. Our aim is to propose in case of skin contamination in EDF NPPs a simply, quickly and reproducible procedure for evaluating skin dose. French regulation admit an annual limit for skin dose over one square centimeter equal to 500 mSv. ICRP Publication 26 and 60 recommend that dose assessment be performed only if skin dose might be equal to or more than 50 mSv at basal cells. To respect this recommendation, an alert value (A) must be determined. This value is the lowest value of measurement from which dose assessment has to be made, based on the hypothesis that uninterrupted work time in controlled area is no more than four hours. This alert value (A) has been established for three external detection equipments, and for the ten radionuclides commonly detected. In case of external contamination, a first measurement is performed. If the value exceeds value (A), other measurements are instituted because skin dose evaluation needs to know other parameters as: - the radioactivity of the most contaminated square centimeter of the skin, - the identity of the radionuclides and their relative proportion. At the same time, we have to evaluate the length of the exposure. At last, we use different compiled results in a program developed from excel software which allow to calculate automatically the skin dose. This work has allowed us to publish an occupational health guideline about the assessment of skin dose in case of external contamination in EDF NPPs and to create an information booklet for workers. The authors propose to examine used methodology and to demonstrate the software. (authors)

  13. Dose evaluation for the public around the Tokai reprocessing plant

    International Nuclear Information System (INIS)

    Takeishi, Minoru; Furuta, Sadaaki; Miyabe, Kenjiro; Shinohara, Kunihiko

    2007-01-01

    The dose evaluations for the public around the Tokai Reprocessing Plant (TRP) have been carried out by using the mathematical models, because the effects on the environmental radiation due to the operation of the TRP are too small to separate from the background level. The models were developed by the site-specific investigations of the environment and reviewed in several times based on the latest scientific knowledge. The maximum annual effective dose through the whole period of the operation of the TRP was evaluated as 1.4 μSv with the data of the discharge monitoring and the meteorological observation in 1992. The evaluated doses revealed to be kept as far below the annual dose limit for the public as 1 mSv. (author)

  14. 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)

  15. 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)

  16. Diagnosis of cerebral metastases by means of standard doses of Gadobutrol versus a high-dose protocol. Intraindividual evaluation of a phase-II high-dose study; Zerebrale Metastasendiagnostik mittels Standarddosis Gadobutrol vs. einem Hochdosisprotokoll. Intraindividuelle Evaluierung einer Phase-II-Hochdosisstudie

    Energy Technology Data Exchange (ETDEWEB)

    Vogl, T.J. [Strahlen- und Poliklinik, Universitaetsklinikum Rudolf Virchow, Freie Univ. Berlin (Germany); Friebe, C.E. [Strahlen- und Poliklinik, Universitaetsklinikum Rudolf Virchow, Freie Univ. Berlin (Germany); Balzer, T. [Schering AG, Berlin (Germany); Mack, M.G. [Strahlen- und Poliklinik, Universitaetsklinikum Rudolf Virchow, Freie Univ. Berlin (Germany); Steiner, S. [Strahlen- und Poliklinik, Universitaetsklinikum Rudolf Virchow, Freie Univ. Berlin (Germany); Schedel, H. [Strahlen- und Poliklinik, Universitaetsklinikum Rudolf Virchow, Freie Univ. Berlin (Germany); Pegios, W. [Strahlen- und Poliklinik, Universitaetsklinikum Rudolf Virchow, Freie Univ. Berlin (Germany); Lanksch, W. [Neurologische Klinik, Universitaetsklinikum Rudolf Virchow, Freie Univ. Berlin (Germany); Banzer, D. [Behring Krankenhaus, Berlin (Germany); Felix, R. [Strahlen- und Poliklinik, Universitaetsklinikum Rudolf Virchow, Freie Univ. Berlin (Germany)

    1995-08-01

    In a clinical phase-II study 20 patients who had been diagnosed as having brain metastases with CT or MRT were studied prospectively with Gadobutrol, a new nonionic, low osmolality contrast agent. Each patient received an initial injection of 0.1 mmol/kg body weight and an additional dose of 0.2 mmol/kg Gadobutrol 10 min later. Spinecho images were obtained before and after the two applications of Gadobutrol. Dynamic scanning (Turbo-FLASH) was performed for 3 min after each injection of the contrast agent. Both quantitative and qualitative data were intraindividually evaluated. The primary tumor was a bronchial carcinoma in 11 cases; in 9 other cases there were different primary tumors. Forty-eight hours after the use of Gadobutrol there were no adverse signs in the clinical examination, vital signs or blood and urine chemistry. Statistical analysis (Friedman test and Wilcoxon test) of the C/N ratios between tumor and white matter, percentage enhancement, and visual assessment rating revealed statistically significant superiority of high-dose Gadobutrol injection in comparison to the standard dose. The percentage enhancement increased on average from 104% after 0.1 mmol/kg to 162% after 0.3 mmol/kg Gadobutrol. Qualitative delineation and contrast of the lesions increased significantly. The use of high-dose Gadobutrol improved the detection of 36 additional lesions in 6 patients. (orig./VHE) [Deutsch] In einer Phase-II-Studie wurden 20 Patienten mit zerebralen Metastasen eines Primaertumors ausserhalb des ZNS mit dem nichtionischen, paramagnetischen Kontrastmittel Gadobutrol magnetresonanztomographisch untersucht. T1- und T2-gewichtete Nativsequenzen und T1-gewichtete Postkontrastsequenzen wurden gemessen nach einer Dosis von 0,1 mmol/kg KG und nach einer additiven Dosis von 0,2 mmol/kg KG Gadobutrol 10 min nach Erstinjektion. Mittels Turbo-FLASH-Sequenzen wurde die Dynamik der Konstrastmittelanreicherung gemessen. Die klinischen und laborchemischen Untersuchungen

  17. Using Population Dose to Evaluate Community-level Health Initiatives.

    Science.gov (United States)

    Harner, Lisa T; Kuo, Elena S; Cheadle, Allen; Rauzon, Suzanne; Schwartz, Pamela M; Parnell, Barbara; Kelly, Cheryl; Solomon, Loel

    2018-05-01

    Successful community-level health initiatives require implementing an effective portfolio of strategies and understanding their impact on population health. These factors are complicated by the heterogeneity of overlapping multicomponent strategies and availability of population-level data that align with the initiatives. To address these complexities, the population dose methodology was developed for planning and evaluating multicomponent community initiatives. Building on the population dose methodology previously developed, this paper operationalizes dose estimates of one initiative targeting youth physical activity as part of the Kaiser Permanente Community Health Initiative, a multicomponent community-level obesity prevention initiative. The technical details needed to operationalize the population dose method are explained, and the use of population dose as an interim proxy for population-level survey data is introduced. The alignment of the estimated impact from strategy-level data analysis using the dose methodology and the data from the population-level survey suggest that dose is useful for conducting real-time evaluation of multiple heterogeneous strategies, and as a viable proxy for existing population-level surveys when robust strategy-level evaluation data are collected. This article is part of a supplement entitled Building Thriving Communities Through Comprehensive Community Health Initiatives, which is sponsored by Kaiser Permanente, Community Health. Copyright © 2018 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.

  18. Problems arising in the evaluation of collective dose commitment

    International Nuclear Information System (INIS)

    Coulon, R.; Beau, P.

    1979-01-01

    In order to apply the concept of optimization it is necessary to evaluate the collective dose commitment for the population as a whole. This is found by summing the dose commitments for the different population groups involved, including persons occupationally exposed and members of the public both locally and globally. The average dose received by each of these groups can vary considerably: for occupational exposure it is about one order of magnitude below the limits, whereas for the general public it is far below, although certain local groups may be subjected to a much higher exposure than the overall average. The question arises, therefore, whether certain groups should not be weighted differently in order to take into account the heterogeneity of the distribution of exposure. As far as the validity of forecast evaluations is concerned, one may assume that for occupational exposure the dose commitment over the whole period of operation of a facility can be estimated fairly accurately. The overall collective dose commitment for the public is relatively insensitive to local variations in the environment and in the public itself but is strongly dependent on long-term developments which cannot at present be forecast. For the evaluation of dose equivalent to the critical group, local variations are of considerable importance and need to be foreseen, which is not always possible. By taking into account a period which includes the annual maximum collective dose equivalent one can make some of these difficulties less severe. (author)

  19. Patient Doses and Risk Evaluation in Bone Mineral Densitometry

    International Nuclear Information System (INIS)

    Angelucci, M.; Borio, R.; Chiocchini, S.; Degli Esposti, P.; Dipilato, A.C.; Policani, G.

    1999-01-01

    The aim of this work was to evaluate the equipment dose to the organs and tissues and the effective dose of patients undergoing the most frequent examinations carried out in bone mineral densitometry (BMD): lumbar spine and femur. Experimental measurements of absorbed doses on a Rando phantom, allow comparison of the performances of three different photon emitter facilities. The comparison of the entrance and exit doses measured on a Rando phantom and on 50 female non-obese patients show that entrance doses on Rando can be used as 'diagnostic reference levels' for patients. A quantitative estimate of the stochastic risk due to BMD procedures was made: the results obtained show that the stochastic risk is very low and that the BMD is, at present, the most confirmed procedure for osteoporosis diagnosis and management. (author)

  20. Improved spatial resolution and lower-dose pediatric CT imaging: a feasibility study to evaluate narrowing the X-ray photon energy spectrum

    Energy Technology Data Exchange (ETDEWEB)

    Benz, Mark G. [Safer Pediatric Imaging and Engineering Horizons International, Lincoln, VT (United States); Benz, Matthew W. [Southboro Medical Group, Southboro, MA (United States); Birnbaum, Steven B. [Dartmouth Hitchcock Clinic Manchester, Department of Radiology, Manchester, NH (United States); Chason, Eric; Sheldon, Brian W. [Brown University, Division of Engineering, Materials Science and Engineering Program, Providence, RI (United States); McGuire, Dale [R and D Manager, C and G Technologies Inc., Jeffersonville, IN (United States)

    2014-08-15

    This feasibility study has shown that improved spatial resolution and reduced radiation dose can be achieved in pediatric CT by narrowing the X-ray photon energy spectrum. This is done by placing a hafnium filter between the X-ray generator and a pediatric abdominal phantom. A CT system manufactured in 1999 that was in the process of being remanufactured was used as the platform for this study. This system had the advantage of easy access to the X-ray generator for modifications to change the X-ray photon energy spectrum; it also had the disadvantage of not employing the latest post-imaging noise reduction iterative reconstruction technology. Because we observed improvements after changing the X-ray photon energy spectrum, we recommend a future study combining this change with an optimized iterative reconstruction noise reduction technique. (orig.)

  1. Personal dosimetry statistics and specifics of low dose evaluation

    International Nuclear Information System (INIS)

    Avila, R.E.; Gómez Salinas, R.A.; Oyarzún Cortés, C.H.

    2015-01-01

    The dose statistics of a personal dosimetry service, considering 35,000+ readings, display a sharp peak at low dose (below 0.5 mSv) with skewness to higher values. A measure of the dispersion is that approximately 65% of the doses fall below the average plus 2 standard deviations, an observation which may prove helpful to radiation protection agencies. Categorizing the doses by the concomitant use of a finger ring dosimeter, that skewness is larger in the whole body, and ring dosimeters. The use of Harshaw 5500 readers at high gain leads to frequent values of the glow curve that are judged to be spurious, i.e. values not belonging to the roughly normal noise over the curve. A statistical criterion is shown for identifying those anomalous values, and replacing them with the local behavior, as fit by a cubic polynomial. As a result, the doses above 0.05 mSv which are affected by more than 2% comprise over 10% of the data base. The low dose peak of the statistics, above, has focused our attention on the evaluation of LiF(Mg,Ti) dosimeters exposed at low dose, and read with Harshaw 5500 readers. The standard linear procedure, via an overall reader calibration factor, is observed to fail at low dose, in detailed calibrations from 0.02 mSv to 1 Sv. A significant improvement is achieved by a piecewise polynomials calibration curve. A cubic, at low dose is matched, at ∼10 mSv, in value and first derivative, to a linear dependence at higher doses. This improvement is particularly noticeable below 2 mSv, where over 60% of the evaluated dosimeters are found. (author)

  2. Dose-to-medium vs. dose-to-water: Dosimetric evaluation of dose reporting modes in Acuros XB for prostate, lung and breast cancer

    Directory of Open Access Journals (Sweden)

    Suresh Rana

    2014-12-01

    Full Text Available Purpose: Acuros XB (AXB dose calculation algorithm is available for external beam photon dose calculations in Eclipse treatment planning system (TPS. The AXB can report the absorbed dose in two modes: dose-to-water (Dw and dose-to-medium (Dm. The main purpose of this study was to compare the dosimetric results of the AXB_Dm with that of AXB_Dw on real patient treatment plans. Methods: Four groups of patients (prostate cancer, stereotactic body radiation therapy (SBRT lung cancer, left breast cancer, and right breast cancer were selected for this study, and each group consisted of 5 cases. The treatment plans of all cases were generated in the Eclipse TPS. For each case, treatment plans were computed using AXB_Dw and AXB_Dm for identical beam arrangements. Dosimetric evaluation was done by comparing various dosimetric parameters in the AXB_Dw plans with that of AXB_Dm plans for the corresponding patient case. Results: For the prostate cancer, the mean planning target volume (PTV dose in the AXB_Dw plans was higher by up to 1.0%, but the mean PTV dose was within ±0.3% for the SBRT lung cancer. The analysis of organs at risk (OAR results in the prostate cancer showed that AXB_Dw plans consistently produced higher values for the bladder and femoral heads but not for the rectum. In the case of SBRT lung cancer, a clear trend was seen for the heart mean dose and spinal cord maximum dose, with AXB_Dw plans producing higher values than the AXB_Dm plans. However, the difference in the lung doses between the AXB_Dm and AXB_Dw plans did not always produce a clear trend, with difference ranged from -1.4% to 2.9%. For both the left and right breast cancer, the AXB_Dm plans produced higher maximum dose to the PTV for all cases. The evaluation of the maximum dose to the skin showed higher values in the AXB_Dm plans for all 5 left breast cancer cases, whereas only 2 cases had higher maximum dose to the skin in the AXB_Dm plans for the right breast cancer

  3. Integral dose and evaluation of irradiated tissue volume

    International Nuclear Information System (INIS)

    Sivachenko, T.P.; Kalina, V.K.; Belous, A.K.; Gaevskij, V.I.

    1984-01-01

    Two parameters having potentialities of radiotherapy planning improvement are under consideration. One of these two parameters in an integral dose. An efficiency of application of special tables for integral dose estimation is noted. These tables were developed by the Kiev Physician Improvement Institute and the Cybernetics Institute of the Ukrainian SSR Academy of Science. The meaning of the term of ''irradiated tissue volume'' is specified, and the method of calculation of the irradiated tissue effective mass is considered. It is possible to evaluate with higher accuracy tolerance doses taking into account the irradiated mass

  4. Evaluation of patient dose in some mammography centres in Iran

    International Nuclear Information System (INIS)

    Paknyat, A.; Samarin, E. R. P.; Jeshvaghane, N. A.; Paydar, R.; Fasaei, B.; Karamloo, A.; Khosravi, H. R.; Deevband, M. R.

    2011-01-01

    High diagnostic sensitivity and specificity while maintaining the least dose to the patient is the ideal mammography. The objective of this work was to evaluate patient dose and image quality of mammograms to propose corrective actions. The image quality for 1242 patient in 7 mammography facilities in Tehran city was evaluated based on selected image quality criteria using a three-point scale. Clinical image quality, the entrance surface air kerma, the average glandular dose and optical density of films for standard PMMA phantom of 4.5 cm thickness were evaluated. The results showed that up to 72 % of mammograms were in good condition to be diagnosed, and only about 3.4 % of the images were unacceptable or with suboptimal quality. The entrance surface air kerma values were in the range of 3.8-10.5 mGy, average glandular dose 0.5-1.8 mGy and optical density of films 0.74-2.03. The image quality evaluation after correction actions, periodic image quality evaluation and using the correct equipment certainly will improve patient dose. (authors)

  5. Evaluation of radiation dose to patients in intraoral dental radiography using Monte Carlo Method

    International Nuclear Information System (INIS)

    Park, Il; Kim, Kyeong Ho; Oh, Seung Chul; Song, Ji Young

    2016-01-01

    The use of dental radiographic examinations is common although radiation dose resulting from the dental radiography is relatively small. Therefore, it is required to evaluate radiation dose from the dental radiography for radiation safety purpose. The objectives of the present study were to develop dosimetry method for intraoral dental radiography using a Monte Carlo method based radiation transport code and to calculate organ doses and effective doses of patients from different types of intraoral radiographies. Radiological properties of dental radiography equipment were characterized for the evaluation of patient radiation dose. The properties including x-ray energy spectrum were simulated using MCNP code. Organ doses and effective doses to patients were calculated by MCNP simulation with computational adult phantoms. At the typical equipment settings (60 kVp, 7 mA, and 0.12 sec), the entrance air kerma was 1.79 mGy and the measured half value layer was 1.82 mm. The half value layer calculated by MCNP simulation was well agreed with the measurement values. Effective doses from intraoral radiographies ranged from 1 μSv for maxilla premolar to 3 μSv for maxilla incisor. Oral cavity layer (23⁓82 μSv) and salivary glands (10⁓68 μSv) received relatively high radiation dose. Thyroid also received high radiation dose (3⁓47 μSv) for examinations. The developed dosimetry method and evaluated radiation doses in this study can be utilized for policy making, patient dose management, and development of low-dose equipment. In addition, this study can ultimately contribute to decrease radiation dose to patients for radiation safety

  6. Evaluation of radiation dose to patients in intraoral dental radiography using Monte Carlo Method

    Energy Technology Data Exchange (ETDEWEB)

    Park, Il; Kim, Kyeong Ho; Oh, Seung Chul; Song, Ji Young [Dept. of Nuclear Engineering, Kyung Hee University, Yongin (Korea, Republic of)

    2016-11-15

    The use of dental radiographic examinations is common although radiation dose resulting from the dental radiography is relatively small. Therefore, it is required to evaluate radiation dose from the dental radiography for radiation safety purpose. The objectives of the present study were to develop dosimetry method for intraoral dental radiography using a Monte Carlo method based radiation transport code and to calculate organ doses and effective doses of patients from different types of intraoral radiographies. Radiological properties of dental radiography equipment were characterized for the evaluation of patient radiation dose. The properties including x-ray energy spectrum were simulated using MCNP code. Organ doses and effective doses to patients were calculated by MCNP simulation with computational adult phantoms. At the typical equipment settings (60 kVp, 7 mA, and 0.12 sec), the entrance air kerma was 1.79 mGy and the measured half value layer was 1.82 mm. The half value layer calculated by MCNP simulation was well agreed with the measurement values. Effective doses from intraoral radiographies ranged from 1 μSv for maxilla premolar to 3 μSv for maxilla incisor. Oral cavity layer (23⁓82 μSv) and salivary glands (10⁓68 μSv) received relatively high radiation dose. Thyroid also received high radiation dose (3⁓47 μSv) for examinations. The developed dosimetry method and evaluated radiation doses in this study can be utilized for policy making, patient dose management, and development of low-dose equipment. In addition, this study can ultimately contribute to decrease radiation dose to patients for radiation safety.

  7. Comparative in vitro evaluation of four corticosteroid metered dose inhalers : Consistency of delivered dose and particle size distribution

    NARCIS (Netherlands)

    de Vries, Tjalling W; Rottier, Bart L; Gjaltema, Doetie; Hagedoorn, Paul; Frijlink, Henderik W; de Boer, Anne H

    2009-01-01

    Introduction: Recent developments concerning pressurized metered dose inhalers (pMDIs) with inhaled corticosteroids (ICS) are the introduction of ciclesonide and the replacement of propellants. As the results of in vivo studies depend on pMDI performance, it is necessary to evaluate pMDIs in vitro

  8. Evaluation of the Occupational Doses of Interventional Radiologists

    International Nuclear Information System (INIS)

    Kuipers, Gerritjan; Velders, Xandra L.; Winter, Robbert J. de; Reekers, Jim A.; Piek, Jan J.

    2008-01-01

    The aim of the present study was to determine whether there is a linear relation between the doses measured above and those measured under the lead apron of the radiologists performing interventional procedures. To monitor radiation exposure the International Commission of Radiological Protection (ICRP) recommends the use of a single dosimeter under the protective apron. To determine the exposure more accurately an additional dosimeter is recommended above the protective apron. The exposure of eight radiologists was monitored with two personal dosimeters during 3 consecutive years. To measure the doses uniformly the two dosimeters were worn in a special holder attached to the lead apron. The two personal dosimeters were replaced every 4 weeks on the same day. The doses above and under the protective aprons of seven radiologists did not differ significantly. A significant lower dose above and under the protective apron was measured for one of the radiologists. During a 4-week period the average dose measured above the lead apron was 3.44 mSv (median, 3.05 mSv), while that under the 0.25-mm lead apron was 0.12 mSv (median, 0.1 mSv). The coefficients of the regression line result in the equation Y = 0.036X - 0.004, with Y as the dose under the lead apron and X as the dose above the lead apron. The statistical analysis of the data established a linear relation between the doses above and those under the lead apron (R 2 = 0.59). Before the special holder was introduced it was not possible to derive a relation between the doses above and those under the lead apron, as the doses were measured at varying places above and under the lead apron. There is no evidence that the effective dose can be estimated more accurately when an additional dosimeter is used. The present study revealed a threshold before doses under the lead apron were measured. Due to the threshold it can be concluded that the doses under the lead apron will not be underestimated easily when doses above the

  9. An open-label dose escalation study to evaluate the safety of administration of nonviral stromal cell-derived factor-1 plasmid to treat symptomatic ischemic heart failure.

    Science.gov (United States)

    Penn, Marc S; Mendelsohn, Farrell O; Schaer, Gary L; Sherman, Warren; Farr, Maryjane; Pastore, Joseph; Rouy, Didier; Clemens, Ruth; Aras, Rahul; Losordo, Douglas W

    2013-03-01

    Preclinical studies indicate that adult stem cells induce tissue repair by activating endogenous stem cells through the stromal cell-derived factor-1:chemokine receptor type 4 axis. JVS-100 is a DNA plasmid encoding human stromal cell-derived factor-1. We tested in a phase 1, open-label, dose-escalation study with 12 months of follow-up in subjects with ischemic cardiomyopathy to see if JVS-100 improves clinical parameters. Seventeen subjects with ischemic cardiomyopathy, New York Heart Association class III heart failure, with an ejection fraction ≤40% on stable medical therapy, were enrolled to receive 5, 15, or 30 mg of JVS-100 via endomyocardial injection. The primary end points for safety and efficacy were at 1 and 4 months, respectively. The primary safety end point was a major adverse cardiac event. Efficacy end points were change in quality of life, New York Heart Association class, 6-minute walk distance, single photon emission computed tomography, N-terminal pro-brain natruretic peptide, and echocardiography at 4 and 12 months. The primary safety end point was met. At 4 months, all of the cohorts demonstrated improvements in 6-minute walk distance, quality of life, and New York Heart Association class. Subjects in the 15- and 30-mg dose groups exhibited improvements in 6-minute walk distance (15 mg: median [range]: 41 minutes [3-61 minutes]; 30 mg: 31 minutes [22-74 minutes]) and quality of life (15 mg: -16 points [+1 to -32 points]; 30 mg: -24 points [+17 to -38 points]) over baseline. At 12 months, improvements in symptoms were maintained. These data highlight the importance of defining the molecular mechanisms of stem cell-based tissue repair and suggest that overexpression of stromal cell-derived factor-1 via gene therapy is a strategy for improving heart failure symptoms in patients with ischemic cardiomyopathy.

  10. Dose evaluation for external exposure in radiation accidents

    International Nuclear Information System (INIS)

    Maruyama, Takashi

    1989-01-01

    Abnormal exposures including emergency and accidental are categorized into external exposure and internal contamination, although both of these may be associated with external contamination. From a point of view of lifesaving in the abnormal exposures, it is primarily important to evaluate radiation dose of exposed persons as soon as possible. This report reviews the status of early dosimetry in the accidental exposures and discusses the optimum methodology of the early dose determination for external exposures in abnormal exposures. Personal monitors generally give an indication of dose to an exposed person only at a single part of the body. The data obtained from the personal monitors should be interpreted with care and in the light of information about the circumstances of exposure. In most cases, the records of environmental monitors or the survey with area monitors provide valuable information on the radiation fields. In the some cases, the reconstruction of the abnormal exposure is required for the dose evaluation by means of phantom experiments. In the case of neutron exposures, activation products in the body or its components or personnel possession can be useful for the early dosimetry. If the dose received by the whole body is evaluated as being very high, clinical observations and biological investigations may be more important guide to initial medical treatment than the early dosimetry. For the dose evaluation of general public, depending on the size of abnormal exposure, information that could be valuable in the assessment of abnormal exposures will come from the early dose estimates with environmental monitors and radiation survey meters. (author)

  11. Evaluation of dose to cardiac structures during breast irradiation

    DEFF Research Database (Denmark)

    Aznar, M C; Korreman, S-S; Pedersen, A N

    2011-01-01

    delivered to the heart and the LAD in respiration-adapted radiotherapy of patients with left-sided breast cancer. METHODS: 24 patients referred for adjuvant radiotherapy after breast-conserving surgery for left-sided lymph node positive breast cancer were evaluated. The whole heart, the arch of the LAD...... and the whole LAD were contoured. The radiation doses to all three cardiac structures were evaluated. RESULTS: For 13 patients, the plans were acceptable based on the criteria set for all 3 contours. For seven patients, the volume of heart irradiated was well below the set clinical threshold whereas a high dose...

  12. Literature study of the radiobiological parameters of Caesium-137 required for evaluating internal irradiation doses as a function of age; Etude bibliographique des parametres radiobiologiques du cesium-137 necessaires a l'evaluation des doses d'irradiation interne en fonction de l'age

    Energy Technology Data Exchange (ETDEWEB)

    Garnier, A [Commissariat a l' Energie Atomique, 92 - Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1968-07-01

    This document reassembles information published in scientific literature on radiobiological parameters of Cs-137, necessary for the estimate of the internal irradiation dose of man according to his age (during growth). The data are completed by a commented review of the mathematical models, proposed in order to value the irradiation doses from ingested cesium and the biological parameters. (author) [French] Ce document rassemble les informations publiees dans la litterature scientifique, concernant les parametres radiobiologiqueo du cesium-137, necessaires a l'evaluation des doses d'irradiation interne de l'homme en fonction de l'age. Ces donnees sont completees par une revue commentee des modeles mathematiques proposes en vue de l'evaluation des doses d'irradiation a partir des quantites de cesium ingerees et des parametres biologiques. (auteur)

  13. Literature study of the radiobiological parameters of Caesium-137 required for evaluating internal irradiation doses as a function of age; Etude bibliographique des parametres radiobiologiques du cesium-137 necessaires a l'evaluation des doses d'irradiation interne en fonction de l'age

    Energy Technology Data Exchange (ETDEWEB)

    Garnier, A. [Commissariat a l' Energie Atomique, 92 - Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1968-07-01

    This document reassembles information published in scientific literature on radiobiological parameters of Cs-137, necessary for the estimate of the internal irradiation dose of man according to his age (during growth). The data are completed by a commented review of the mathematical models, proposed in order to value the irradiation doses from ingested cesium and the biological parameters. (author) [French] Ce document rassemble les informations publiees dans la litterature scientifique, concernant les parametres radiobiologiqueo du cesium-137, necessaires a l'evaluation des doses d'irradiation interne de l'homme en fonction de l'age. Ces donnees sont completees par une revue commentee des modeles mathematiques proposes en vue de l'evaluation des doses d'irradiation a partir des quantites de cesium ingerees et des parametres biologiques. (auteur)

  14. Improvement of dose evaluation method for employees at severe accident

    International Nuclear Information System (INIS)

    Onda, Takashi; Yoshida, Yoshitaka; Kudo, Seiichi; Nishimura, Kazuya

    2003-01-01

    It is expected that the selection of access routes for employees who engage in emergency work at a severe accident in a nuclear power plant makes a difference in their radiation dose values. In order to examine how much difference arises in the dose by the selection of the access routes, in the case of a severe accident in a pressurized water reactor plant, we improved the method to obtain the dose for employees and expanded the analyzing system. By the expansion of the system and the improvement of the method, we have realized the followings: (1) in the whole plant area, the dose evaluation is possible, (2) the efficiency of calculation is increased by the reduction of the number of radiation sources, etc, and (3) the function is improved by introduction of the sky shine calculation into the highest floor, etc. The improved system clarifies the followings: (1) the doses change by selected access routes, and this system can give the difference in the doses quantitatively, and (2) in order to suppress the dose, it is effective to choose the most adequate access route for the employees. (author)

  15. Evaluating correlation between geometrical relationship and dose difference caused by respiratory motion using statistical analysis

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Dong Seok; Kim, Dong Su; Kim, Tae Ho; Kim, Kyeong Hyeon; Yoon, Do Kun; Suh, Tae Suk [The Catholic University of Korea, Seoul (Korea, Republic of); Kang, Seong Hee [Seoul National University Hospital, Seoul (Korea, Republic of); Cho, Min Seok [Asan Medical Center, Seoul (Korea, Republic of); Noh, Yu Yoon [Eulji University Hospital, Daejeon (Korea, Republic of)

    2017-04-15

    Three-dimensional dose (3D dose) can consider coverage of moving target, however it is difficult to provide dosimetric effect which occurs by respiratory motions. Four-dimensional dose (4D dose) which uses deformable image registration (DIR) algorithm from four-dimensional computed tomography (4DCT) images can consider dosimetric effect by respiratory motions. The dose difference between 3D dose and 4D dose can be varied according to the geometrical relationship between a planning target volume (PTV) and an organ at risk (OAR). The purpose of this study is to evaluate the correlation between the overlap volume histogram (OVH), which quantitatively shows the geometrical relationship between the PTV and OAR, and the dose differences. In conclusion, no significant statistical correlation was found between the OVH and dose differences. However, it was confirmed that a higher difference between the 3D and 4D doses could occur in cases that have smaller OVH value. No significant statistical correlation was found between the OVH and dose differences. However, it was confirmed that a higher difference between the 3D and 4D doses could occur in cases that have smaller OVH value.

  16. Dose evaluation of TPS according to treatment sites in IMRT

    International Nuclear Information System (INIS)

    Kim, Jin Man; Kim, Jong Sik; Hong, Chae Seon; Park, Ju Young; Park, Su Yeon; Ju, Sang Gyu

    2013-01-01

    This study executed therapy plans on prostate cancer (homogeneous density area) and lung cancer (non-homogeneous density area) using radiation treatment planning systems such as Pinnacle 3 (version 9.2, Philips Medical Systems, USA) and Eclipse (version 10.0, Varian Medical Systems, USA) in order to quantify the difference between dose calculation according to density in IMRT. The subjects were prostate cancer patients (n=5) and lung cancer patients (n=5) who had therapies in our hospital. Identical constraints and optimization process according to the Protocol were administered on the subjects. For the therapy plan of prostate cancer patients, 10 MV and 7Beam were used and 2.5 Gy was prescribed in 28 fx to make 70 Gy in total. For lung cancer patients, 6 MV and 6Beam were used and 2 Gy was prescribed in 33 fx to make 66 Gy in total. Through two therapy planning systems, maximum dose, average dose, and minimum dose of OAR (Organ at Risk) of CTV, PTV and around tumor were investigated. In prostate cancer, both therapy planning systems showed within 2% change of dose of CTV and PTV and normal organs (Bladder, Both femur and Rectum out) near the tumor satisfied the dose constraints. In lung cancer, CTV and PTV showed less than 2% changes in dose and normal organs (Esophagus, Spinal cord and Both lungs) satisfied dose restrictions. However, the minimum dose of Eclipse therapy plan was 1.9% higher in CTV and 3.5% higher in PTV, and in case of both lungs there was 3.0% difference at V5 Gy. Each TPS according to the density satisfied dose limits of our hospital proving the clinical accuracy. It is considered more accurate and precise therapy plan can be made if studies on treatment planning for diverse parts and the application of such TPS are made

  17. Principles of protection: a formal approach for evaluating dose distributions

    International Nuclear Information System (INIS)

    Wikman-Svahn, Per; Peterson, Martin; Hansson, Sven Ove

    2006-01-01

    One of the central issues in radiation protection consists in determining what weight should be given to individual doses in relation to collective or aggregated doses. A mathematical framework is introduced in which such assessments can be made precisely in terms of comparisons between alternative distributions of individual doses. In addition to evaluation principles that are well known from radiation protection, a series of principles that are derived from parallel discussions in moral philosophy and welfare economics is investigated. A battery of formal properties is then used to investigate the evaluative principles. The results indicate that one of the new principles, bilinear prioritarianism, may be preferable to current practices, since it satisfies efficiency-related properties better without sacrificing other desirable properties

  18. Randomized, double-blind, placebo-controlled, linear dose, crossover study to evaluate the efficacy and safety of a green coffee bean extract in overweight subjects

    Directory of Open Access Journals (Sweden)

    Vinson JA

    2012-01-01

    Full Text Available Joe A Vinson1, Bryan R Burnham3, Mysore V Nagendran31Chemistry Department, 2Psychology Department, University of Scranton, Scranton, PA, USA; 3Health Sciences Clinic, Bangalore, IndiaBackground: Adult weight gain and obesity have become worldwide problems. Issues of cost and potential side effects of prescription weight loss drugs have led overweight and obese adults to try nutraceuticals that may aid weight loss. One promising nutraceutical is green coffee extract, which contains high concentrations of chlorogenic acids hat are known to have health benefits and to influence glucose and fat metabolism. A 22-week crossover study was conducted to examine the efficacy and safety of a commercial green coffee extract product GCA™ at reducing weight and body mass in 16 overweight adults.Methods: Subjects received high-dose GCA (1050 mg, low-dose GCA (700 mg, or placebo in separate six-week treatment periods followed by two-week washout periods to reduce any influence of preceding treatment. Treatments were counterbalanced between subjects. Primary measurements were body weight, body mass index, and percent body fat. Heart rate and blood pressure were also measured.Results: Significant reductions were observed in body weight (-8.04 ± 2.31 kg, body mass index (-2.92 ± 0.85 kg/m2, and percent body fat (-4.44% ± 2.00%, as well as a small decrease in heart rate (-2.56 ± 2.85 beats per minute, but with no significant changes to diet over the course of the study. Importantly, the decreases occurred when subjects were taking GCA. Body mass index for six subjects shifted from preobesity to the normal weight range (<25.00 kg/m2.Conclusion: The results are consistent with human and animal studies and a meta-analysis of the efficacy of green coffee extract in weight loss. The results suggest that GCA may be an effective nutraceutical in reducing weight in preobese adults, and may be an inexpensive means of preventing obesity in overweight adults

  19. Current evaluation of dose rate calculation - analytical method

    International Nuclear Information System (INIS)

    Tello, Marcos; Vilhena, Marco Tulio

    1996-01-01

    The accuracy of the dose calculations based on pencil beam formulas such as Fokker-Plank equations and Fermi equations for charged particle transport are studied and a methodology to solve the Boltzmann transport equation is suggested

  20. Dose rate evaluation after accident in a PWR

    International Nuclear Information System (INIS)

    Cladel, C.; Duchemin, B.; Le Dieu de Ville, A.; Nimal, B.; Nimal, J.C.; Evrard, J.M.

    1983-05-01

    A calculation scheme for the gamma radiation dose rate after accident in a PWR is presented. These studies use a fine description of the geometry and of the fission product inventory. Some results are given and some improvements are planned

  1. Comparison of the dose evaluation methods for criticality accident

    International Nuclear Information System (INIS)

    Shimizu, Yoshio; Oka, Tsutomu

    2004-01-01

    The improvement of the dose evaluation method for criticality accidents is important to rationalize design of the nuclear fuel cycle facilities. The source spectrums of neutron and gamma ray of a criticality accident depend on the condition of the source, its materials, moderation, density and so on. The comparison of the dose evaluation methods for a criticality accident is made. Some methods, which are combination of criticality calculation and shielding calculation, are proposed. Prompt neutron and gamma ray doses from nuclear criticality of some uranium systems have been evaluated as the Nuclear Criticality Slide Rule. The uranium metal source (unmoderated system) and the uranyl nitrate solution source (moderated system) in the rule are evaluated by some calculation methods, which are combinations of code and cross section library, as follows: (a) SAS1X (ENDF/B-IV), (b) MCNP4C (ENDF/B-VI)-ANISN (DLC23E or JSD120), (c) MCNP4C-MCNP4C (ENDF/B-VI). They have consisted of criticality calculation and shielding calculation. These calculation methods are compared about the tissue absorbed dose and the spectrums at 2 m from the source. (author)

  2. Evaluation of occupational radiation dose of extremities on hysterosalpingography

    International Nuclear Information System (INIS)

    Filipov, D.; Kotowski, S.T.A.

    2017-01-01

    In the Hysterosalpingography (HSG) exam there is always a professional present with their hands very close to the radiation field. Based on CNEN, individuals occupationally exposed to radiation have equivalent dose limit values for the extremities (500 mSv / year). The objective of the study was to verify the equivalent dose in the hand region of an IOE (Occupationally Exposed Individual) that performs the HSG test and to compare it with the CNEN limit and with similar studies. A humanoid phantom was used to simulate the patient and an ionization chamber, which was placed in the place commonly occupied by the professional. The equivalent hand dose result (∼ 30 mSv / year) equals 6% of the CNEN annual dose limit, but is close to most studies using fluoroscopes. Therefore, the optimization of radiological protection is necessary to reduce these results

  3. Collaborative work to evaluate toxicity on male reproductive organs by repeated dose studies in rats 22). Effects of 2- and 4-week administration of theobromine on the testis.

    Science.gov (United States)

    Funabashi, H; Fujioka, M; Kohchi, M; Tateishi, Y; Matsuoka, N

    2000-10-01

    The effects of theobromine, a xanthine derivative, on the testis were compared between rats dosed for 2 and 4 weeks to determine whether a 2-week dosing period is long enough to detect toxicity. Theobromine was administered orally to male Sprague-Dawley rats at dose levels of 250 and 500 mg/kg for 2 weeks starting at the age of 6 or 8 weeks, and for 4 weeks from the age of 6 weeks. Histopathological examination of reproductive organs revealed toxic findings in the testis at 500 mg/kg after 2 weeks of dosing at both ages, and at 250 and 500 mg/kg after 4 weeks of dosing. The primary findings were degeneration/necrosis and desquamation of spermatids and spermatocytes, vacuolization of seminiferous tubules, and multinucleated giant cell formation. These findings were present mainly in stages I-VI and XII-XIV. From these results, it is concluded that the toxic effects of theobromine on the testis can be detected by repeated dosing for 2 weeks as well as for 4 weeks.

  4. A phase I, randomized, single-dose study evaluating the pharmacokinetic equivalence of biosimilar ABP 215 and bevacizumab in healthy adult men.

    Science.gov (United States)

    Markus, Richard; Chow, Vincent; Pan, Zhiying; Hanes, Vladimir

    2017-10-01

    This study compared the pharmacokinetic (PK) profiles of the proposed biosimilar ABP 215 with bevacizumab in healthy males. In this randomized, single-blind, single-dose, three-arm, parallel-group study, healthy subjects were randomized to receive ABP 215 (n = 68), bevacizumab (US) (n = 67), or bevacizumab (EU) (n = 67) 3 mg/kg intravenously. Primary endpoints were area under the serum concentration-time curve from time 0 extrapolated to infinity (AUC inf ) and the maximum observed concentration (C max ). Secondary endpoints included safety and immunogenicity. AUC inf and C max were similar across the three groups. Geometric means ratio (GMR) for C max and AUC inf , respectively, was 0.98 and 0.99 for ABP 215 versus bevacizumab (US); 1.03 and 0.96 for ABP 215 versus bevacizumab (EU); and 1.05 and 0.97 for bevacizumab (US) versus bevacizumab (EU). The 90% confidence intervals for the GMRs of AUC inf and C max were within the prespecified standard PK bioequivalence criteria of 0.80 to 1.25. The incidence of adverse events (AEs) was 47.1, 32.8, and 61.2% in the ABP 215, bevacizumab (US) and bevacizumab (EU) groups, respectively. When analyzed by investigational site, the incidence and severity of AEs were comparable in the ABP 215 and bevacizumab groups. There were no AEs leading to study discontinuation. No binding or neutralizing anti-drug anti-bodies was detected. This study demonstrated the PK similarity of ABP 215 to both bevacizumab (US) and bevacizumab (EU), and of bevacizumab (US) to bevacizumab (EU). Safety and tolerability were comparable between treatments and no subject developed binding or neutralizing anti-drug anti-bodies.

  5. Evaluation of a post-analysis method for cumulative dose distribution in stereotactic body radiotherapy

    International Nuclear Information System (INIS)

    Imae, Toshikazu; Takenaka, Shigeharu; Saotome, Naoya

    2016-01-01

    The purpose of this study was to evaluate a post-analysis method for cumulative dose distribution in stereotactic body radiotherapy (SBRT) using volumetric modulated arc therapy (VMAT). VMAT is capable of acquiring respiratory signals derived from projection images and machine parameters based on machine logs during VMAT delivery. Dose distributions were reconstructed from the respiratory signals and machine parameters in the condition where respiratory signals were without division, divided into 4 and 10 phases. The dose distribution of each respiratory phase was calculated on the planned four-dimensional CT (4DCT). Summation of the dose distributions was carried out using deformable image registration (DIR), and cumulative dose distributions were compared with those of the corresponding plans. Without division, dose differences between cumulative distribution and plan were not significant. In the condition Where respiratory signals were divided, dose differences were observed over dose in cranial region and under dose in caudal region of planning target volume (PTV). Differences between 4 and 10 phases were not significant. The present method Was feasible for evaluating cumulative dose distribution in VMAT-SBRT using 4DCT and DIR. (author)

  6. Evaluation of radiation dose received in skull radiographic examination

    International Nuclear Information System (INIS)

    Omer, Noora Elshiekh

    2014-12-01

    Diagnostic X-ray examination play an important role in the health care of the population. These examinations may involve significant irradiation of the patient and probably represent the largest mam-made source of radiation exposure for the population. This study was performed in Khartoum Teaching Hospital in period of January to June 2014. This study was performed to assess the effective dose (ED) received in skull radiographic examination and to analyze effective dose distributions among radiological department under study. The study was performed in Khartoum Teaching Hospital, covering two x-ray units and a sample of 50 patients. The following parameters were recorded: age, weight, height, body mass index (BMI) derived from weight (kg) and (height (m)) and exposure factors. The dose was measured for skull x-ray examinations. For effective dose calculation, the entrance surface dose (ESD) values were estimated from the x-ray tube output parameters for skull AP and lateral examinations. The ED values were then calculated from the obtained ESD values using IAEA calculation methods. Effective doses were calculated from energy imparted using ED conversion factors proposed were within the normal range of exposure. The mean ED values calculated were 3.03±0.08 and 4.23±0.61 for skull AP and lateral examination, respectively. Further studies are recommended with more number of patients and using more than two modalities for comparison. (Author)

  7. Evaluating adherence to ocular hypotensives using the Travatan dosing aid

    Directory of Open Access Journals (Sweden)

    O'Dell L

    2012-01-01

    Full Text Available Leslie O'Dell1, Amy L Hennessy2,3, Alan L Robin2–41May Eye Care Center, Hanover, PA, USA; 2Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA; 3Glaucoma Specialists, Baltimore, MD, USA; 4Wilmer Eye Institute, Johns Hopkins School of Medicine, Baltimore, MD, USAPurpose: The Travatan™ Dosing Aid (TDA is the first commercially available device designed to aid in patients' adherence to their glaucoma therapies and to record patients' eyedrop administration, so that doctors can better assess adherence. No prior studies have objectively evaluated adherence to glaucoma medications and its relationship to the severity of glaucoma or the use of multiple systemic medications.Methods: We enrolled 100 consecutive subjects from a private glaucoma practice, all currently using topical travoprost 0.004%. Each subject was issued a TDA to record the time and date of each drop instilled. Informed consents were signed and the subjects were aware that their medication use was being monitored. Patients returned for follow-up 30–60 days after their initial exam.Results: 89 subjects completed the study: 44 were male, with a mean age of 67 years, and 69.7% were Caucasian. Overall, patient adherence was 74.8% (range 22%–100% improving to 85.4% on the day prior to follow-up. The mean number of missed doses per month was 6.24 ± 5.9. Only 7.9% of the study population never missed a dose and 23.6% ± 4.3% missed more than ten drops per month. No marked association was observed between the severity of glaucoma, race, or the number of systemic medications and adherence. A marked improvement in adherence was noted in patients using travoprost 0.004% as monocular therapy rather than binocular therapy, 84.0% ± 17.1% vs 67.4% ± 23.5% (P < 0.005.Conclusion: Patient adherence to glaucoma medical therapy is a major barrier in the management and treatment of glaucoma patients given the chronic nature and asymptomatic course of the disease. Until recently

  8. A randomized double-blinded placebo-controlled study to evaluate an effective ciclosporin dose for the treatment of feline hypersensitivity dermatitis.

    Science.gov (United States)

    King, Stephen; Favrot, Claude; Messinger, Linda; Nuttall, Tim; Steffan, Jean; Forster, Sophie; Seewald, Wolfgang

    2012-10-01

    Hypersensitivity dermatitides (HD) are frequently suspected in cats, but there are few clinical studies on safe and effective treatments in the published literature. To establish a safe and effective dose of ciclosporin in the treatment of feline HD. One hundred client-owned cats with feline HD. Double-blind study, with cats randomly assigned to receive ciclosporin at either 7.0 mg/kg once daily (n = 33) or 2.5 mg/kg once daily (n = 32) or a placebo (n = 35) for 6 weeks. Mean Total Lesion Scores with 7.0 mg/kg ciclosporin were significantly lower than with 2.5 mg/kg ciclosporin (P = 0.0047) or placebo (P = 0.0003) at study end. Individual Total Lesion Scores improved by >50% in 70% of the 7.0 mg/kg group, compared with 47% in the 2.5 mg/kg group and 23% in the placebo group (P = 0.0006). The investigators' Global Assessment of Improvement was 'excellent' or 'good' in 61% of cats treated with 7.0 mg/kg ciclosporin, compared with 47% of cats given 2.5 mg/kg and 23% given placebo. The improvement in Investigator Pruritus Scores was significantly greater in cats treated with 7.0 mg/kg ciclosporin (54%) compared with both 2.5 mg/kg ciclosporin (32%; P = 0.0232) and placebo (21%; P = 0.0063). Mild gastrointestinal disorders were the most common adverse events, but these did not require cessation of therapy. Results suggest that 7.0 mg/kg ciclosporin once daily in food or per os for 6 weeks is effective and well tolerated in feline HD. © 2012 The Authors. Veterinary Dermatology © 2012 ESVD and ACVD.

  9. Evaluation of the original dose in irradiated dried fruit by EPR spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    D' Oca, Maria Cristina, E-mail: mcristina.doca@unipa.it [Dipartimento Farmacochimico, Tossicologico e Biologico, Universita di Palermo, via Archirafi 32, 90123 Palermo (Italy); Bartolotta, Antonio [Dipartimento Farmacochimico, Tossicologico e Biologico, Universita di Palermo, via Archirafi 32, 90123 Palermo (Italy)

    2011-09-15

    The electron paramagnetic resonance spectroscopy (EPR) is one of the physical methods, recommended by the European Committee for Standardization, for the identification of irradiated food containing cellulose, such as dried fruit. In this work the applicability of EPR as identification method of irradiated pistachios, hazelnuts, peanuts, chestnuts, pumpkin seeds is evaluated; the time stability of the radiation induced signal is studied and the single aliquot additive dose method is used to evaluate the dose in the product.

  10. Evaluation of the original dose in irradiated dried fruit by EPR spectroscopy

    International Nuclear Information System (INIS)

    D'Oca, Maria Cristina; Bartolotta, Antonio

    2011-01-01

    The electron paramagnetic resonance spectroscopy (EPR) is one of the physical methods, recommended by the European Committee for Standardization, for the identification of irradiated food containing cellulose, such as dried fruit. In this work the applicability of EPR as identification method of irradiated pistachios, hazelnuts, peanuts, chestnuts, pumpkin seeds is evaluated; the time stability of the radiation induced signal is studied and the single aliquot additive dose method is used to evaluate the dose in the product.

  11. Identifying the most successful dose (MSD) in dose-finding studies in cancer.

    Science.gov (United States)

    Zohar, Sarah; O'Quigley, John

    2006-01-01

    For a dose finding study in cancer, the most successful dose (MSD), among a group of available doses, is that dose at which the overall success rate is the highest. This rate is the product of the rate of seeing non-toxicities together with the rate of tumor response. A successful dose finding trial in this context is one where we manage to identify the MSD in an efficient manner. In practice we may also need to consider algorithms for identifying the MSD which can incorporate certain restrictions, the most common restriction maintaining the estimated toxicity rate alone below some maximum rate. In this case the MSD may correspond to a different level than that for the unconstrained MSD and, in providing a final recommendation, it is important to underline that it is subject to the given constraint. We work with the approach described in O'Quigley et al. [Biometrics 2001; 57(4):1018-1029]. The focus of that work was dose finding in HIV where both information on toxicity and efficacy were almost immediately available. Recent cancer studies are beginning to fall under this same heading where, as before, toxicity can be quickly evaluated and, in addition, we can rely on biological markers or other measures of tumor response. Mindful of the particular context of cancer, our purpose here is to consider the methodology developed by O'Quigley et al. and its practical implementation. We also carry out a study on the doubly under-parameterized model, developed by O'Quigley et al. but not

  12. SU-G-BRC-08: Evaluation of Dose Mass Histogram as a More Representative Dose Description Method Than Dose Volume Histogram in Lung Cancer Patients

    Energy Technology Data Exchange (ETDEWEB)

    Liu, J; Eldib, A; Ma, C [Fox Chase Cancer Center, Philadelphia, PA (United States); Lin, M [The University of Texas Southwestern Medical Ctr, Dallas, TX (United States); Li, J [Cyber Medical Inc, Xian, Shaanxi (China); Mora, G [Universidade de Lisboa, Codex, Lisboa (Portugal)

    2016-06-15

    Purpose: Dose-volume-histogram (DVH) is widely used for plan evaluation in radiation treatment. The concept of dose-mass-histogram (DMH) is expected to provide a more representative description as it accounts for heterogeneity in tissue density. This study is intended to assess the difference between DVH and DMH for evaluating treatment planning quality. Methods: 12 lung cancer treatment plans were exported from the treatment planning system. DVHs for the planning target volume (PTV), the normal lung and other structures of interest were calculated. DMHs were calculated in a similar way as DVHs expect that the voxel density converted from the CT number was used in tallying the dose histogram bins. The equivalent uniform dose (EUD) was calculated based on voxel volume and mass, respectively. The normal tissue complication probability (NTCP) in relation to the EUD was calculated for the normal lung to provide quantitative comparison of DVHs and DMHs for evaluating the radiobiological effect. Results: Large differences were observed between DVHs and DMHs for lungs and PTVs. For PTVs with dense tumor cores, DMHs are higher than DVHs due to larger mass weighing in the high dose conformal core regions. For the normal lungs, DMHs can either be higher or lower than DVHs depending on the target location within the lung. When the target is close to the lower lung, DMHs show higher values than DVHs because the lower lung has higher density than the central portion or the upper lung. DMHs are lower than DVHs for targets in the upper lung. The calculated NTCPs showed a large range of difference between DVHs and DMHs. Conclusion: The heterogeneity of lung can be well considered using DMH for evaluating target coverage and normal lung pneumonitis. Further studies are warranted to quantify the benefits of DMH over DVH for plan quality evaluation.

  13. Antipsychotic treatment dosing profile in patients with schizophrenia evaluated with electronic monitoring (MEMS®).

    Science.gov (United States)

    Acosta, Francisco J; Ramallo-Fariña, Yolanda; Bosch, Esperanza; Mayans, Teresa; Rodríguez, Carlos J; Caravaca, Ana

    2013-05-01

    Although the Medication Event Monitoring System (MEMS®) device offers accurate information on treatment dosing profile, such profile has never been studied in patients with schizophrenia. Enhancing our knowledge on this issue would help in developing intervention strategies to improve adherence to antipsychotic treatment in these patients. 74 outpatients with schizophrenia were monitored with the MEMS device for a 3-month period, for evaluation of antipsychotic treatment dosing profile, possible influence of medication schedule-related variables, adherence to treatment--considering dose intake within prescribed timeframes--and possible Hawthorne's effect of using the MEMS device. Dose-omission gaps occurred in 18.7% of monitoring days, most frequently during weekends, almost significantly. Almost one-third of prescribed doses were taken out of prescribed time. Neither the prescribed number of daily doses nor the indicated time of the day for dose intake (breakfast, dinner), were associated with correct antipsychotic dosing. Excess-dose was rare in general, and more frequent out of prescribed dose timeframe. No Hawthorne's effect was found for the MEMS device. Adherence reached only 35% according to a definition that included dose intake within prescribed timeframes. Antipsychotic treatment dosing was considerably irregular among patients with schizophrenia. Strategies to reduce dose-omission gaps and increase dosing within prescribed timeframes seem to be necessary. Gaining knowledge on precise oral antipsychotic dosing profiles or the influence of schedule-related variables may be useful to design strategies towards enhancing adherence. There appears to be no Hawthorne's effect associated with the use of MEMS devices in outpatients with schizophrenia. Copyright © 2013 Elsevier B.V. All rights reserved.

  14. Leprosy Post-Exposure Prophylaxis (LPEP) programme: study protocol for evaluating the feasibility and impact on case detection rates of contact tracing and single dose rifampicin.

    Science.gov (United States)

    Barth-Jaeggi, Tanja; Steinmann, Peter; Mieras, Liesbeth; van Brakel, Wim; Richardus, Jan Hendrik; Tiwari, Anuj; Bratschi, Martin; Cavaliero, Arielle; Vander Plaetse, Bart; Mirza, Fareed; Aerts, Ann

    2016-11-17

    The reported number of new leprosy patients has barely changed in recent years. Thus, additional approaches or modifications to the current standard of passive case detection are needed to interrupt leprosy transmission. Large-scale clinical trials with single dose rifampicin (SDR) given as post-exposure prophylaxis (PEP) to contacts of newly diagnosed patients with leprosy have shown a 50-60% reduction of the risk of developing leprosy over the following 2 years. To accelerate the uptake of this evidence and introduction of PEP into national leprosy programmes, data on the effectiveness, impact and feasibility of contact tracing and PEP for leprosy are required. The leprosy post-exposure prophylaxis (LPEP) programme was designed to obtain those data. The LPEP programme evaluates feasibility, effectiveness and impact of PEP with SDR in pilot areas situated in several leprosy endemic countries: India, Indonesia, Myanmar, Nepal, Sri Lanka and Tanzania. Complementary sites are located in Brazil and Cambodia. From 2015 to 2018, contact persons of patients with leprosy are traced, screened for symptoms and assessed for eligibility to receive SDR. The intervention is implemented by the national leprosy programmes, tailored to local conditions and capacities, and relying on available human and material resources. It is coordinated on the ground with the help of the in-country partners of the International Federation of Anti-Leprosy Associations (ILEP). A robust data collection and reporting system is established in the pilot areas with regular monitoring and quality control, contributing to the strengthening of the national surveillance systems to become more action-oriented. Ethical approval has been obtained from the relevant ethics committees in the countries. Results and lessons learnt from the LPEP programme will be published in peer-reviewed journals and should provide important evidence and guidance for national and global policymakers to strengthen current

  15. Two gamma dose evaluation methods for silicon semiconductor detector

    International Nuclear Information System (INIS)

    Chen Faguo; Jin Gen; Yang Yapeng; Xu Yuan

    2011-01-01

    Silicon PIN diodes have been widely used as personal and areal dosimeters because of their small volume, simplicity and real-time operation. However, because silicon is neither a tissue-equivalent nor an air-equivalent material, an intrinsic disadvantage for silicon dosimeters is that a significant over-response occurs at low-energy region, especially below 200 keV. Using a energy compensation filter to flatten the energy response is one method overcoming this disadvantage. But for dose compensation method, the estimated dose depends only on the number of the detector pulses. So a weight function method was introduced to evaluate gamma dose, which depends on pulse number as well as its amplitude. (authors)

  16. Doses for post-Chernobyl epidemiological studies: are they reliable?

    Science.gov (United States)

    Drozdovitch, Vladimir; Chumak, Vadim; Kesminiene, Ausrele; Ostroumova, Evgenia; Bouville, André

    2016-09-01

    On 26 April 2016, thirty years will have elapsed since the occurrence of the Chernobyl accident, which has so far been the most severe in the history of the nuclear reactor industry. Numerous epidemiological studies were conducted to evaluate the possible health consequences of the accident. Since the credibility of the association between the radiation exposure and health outcome is highly dependent on the adequacy of the dosimetric quantities used in these studies, this paper makes an effort to overview the methods used to estimate individual doses and the associated uncertainties in the main analytical epidemiological studies (i.e. cohort or case-control) related to the Chernobyl accident. Based on the thorough analysis and comparison with other radiation studies, the authors conclude that individual doses for the Chernobyl analytical epidemiological studies have been calculated with a relatively high degree of reliability and well-characterized uncertainties, and that they compare favorably with many other non-Chernobyl studies. The major strengths of the Chernobyl studies are: (1) they are grounded on a large number of measurements, either performed on humans or made in the environment; and (2) extensive effort has been invested to evaluate the uncertainties associated with the dose estimates. Nevertheless, gaps in the methodology are identified and suggestions for the possible improvement of the current dose estimates are made.

  17. Evaluation of a liver micronucleus assay in young rats (IV): a study using a double-dosing/single-sampling method by the Collaborative Study Group for the Micronucleus Test (CSGMT)/Japanese Environmental Mutagen Society (JEMS)-Mammalian Mutagenicity Study Group (MMS).

    Science.gov (United States)

    Takasawa, Hironao; Suzuki, Hiroshi; Ogawa, Izumi; Shimada, Yasushi; Kobayashi, Kazuo; Terashima, Yukari; Matsumoto, Hirotaka; Oshida, Keiyu; Ohta, Ryo; Imamura, Tadashi; Miyazaki, Atsushi; Kawabata, Masayoshi; Minowa, Shigenori; Maeda, Akihisa; Hayashi, Makoto

    2010-04-30

    A collaborative study was conducted to evaluate whether a liver micronucleus assay using four-week-old male F344 rats can be used to detect genotoxic rat hepatocarcinogens using double-dosing with a single-sampling 4 days after the second dose. The assay methods were thoroughly validated by the seven laboratories involved in the study. Seven chemicals, 2,4-diaminotoluene, diethyl nitrosamine, p-dimethylaminoazobenzene, 1,2-dimethylhydrazine dihydrochloride, 2,4-dinitrotolunene, 2,6-dinitrotoluene and mitomycin C, known to produce positive responses in the single-dosing/triple-sampling method were selected for use in the present study, and each chemical was examined in two laboratories with the exception of 2,4-dinitrotolunene. Although several of the compounds were examined at lower doses for reasons of toxicity than in the single-dosing/triple-sampling method, all chemicals tested in the present study induced micronuclei in liver cells indicating a positive result. These findings suggest that the liver micronucleus assay can be used in young rats to detect genotoxic rat hepatocarcinogens using a double-dosing/single-sampling procedure. Further, the number of animals used in the liver micronucleus assay can be reduced by one-third to a half by using the double-dosing/single-sampling method. This reduction in animal numbers also has significant savings in time and resource for liver perfusion and hepatocyte isolation. Copyright 2010 Elsevier B.V. All rights reserved.

  18. Evaluation of dose exposure in 64-slice CT colonography

    Energy Technology Data Exchange (ETDEWEB)

    Luz, O.; Trabold, T.; Kopp, A.F.; Claussen, C.D.; Heuschmid, M. [University Hospital Tuebingen, Department of Diagnostic Radiology, Tuebingen (Germany); Buchgeister, M.; Klabunde, M. [University of Tuebingen, Institute of Medical Physics, Tuebingen (Germany)

    2007-10-15

    The radiation exposure of four different 64-slice MDCT-colonography (CTC) protocols was evaluated using an Alderson-Rando phantom. Protocols using 30 mAs (collimation 20 x 1.2mm), 50 mAs (collimation 20 x 1.2 and 64 x 0.6mm) and 80 mAs (20 x 1.2 mm) representing screening low-dose, routine, narrow collimation and oncologic staging setups were measured with an Alderson-Rando phantom (Alderson Research Laboratories Inc.). Scans were performed on a 64-row MDCT (SOMATOM Sensation 64, Siemens) simulating the prone and supine positions with a constant voltage of 120 kV. Dose values (male/female) were 2.5/2.9, 3.8/4.2, 4.2/4.5 and 5.7/6.4 mSv for 30, 50 (20 x 1.2 and 64 x 0.6 mm) and 80 mAs, respectively. Measurements showed an elevated dose for females (11.5% mean; compared to males). Use of narrow collimation combined with 50 mAs resulted in a small increase of dose exposure of 10.5 (male) and 7.1% (female). Gonad doses ranged from 0.9 to 2.6 mSv (male) and from 1.5 to 3.5 mSv (female). In all protocols, the stomach wall, lower colon, urinary bladder and liver were slightly more highly exposed (all <2.3 mSv) than the other organs, and the breast dose was <0.3 mSv in every setup. Values of radiation exposure in 64- and 16-slice CTC differ only marginally when using the narrow collimation. In 64-slice CTC, the use of narrow (64 x 0.6 mm) collimation shows slightly elevated dose values compared to wider (20 x 1.2 mm) collimation. (orig.)

  19. Evaluation of dose exposure in 64-slice CT colonography

    International Nuclear Information System (INIS)

    Luz, O.; Trabold, T.; Kopp, A.F.; Claussen, C.D.; Heuschmid, M.; Buchgeister, M.; Klabunde, M.

    2007-01-01

    The radiation exposure of four different 64-slice MDCT-colonography (CTC) protocols was evaluated using an Alderson-Rando phantom. Protocols using 30 mAs (collimation 20 x 1.2mm), 50 mAs (collimation 20 x 1.2 and 64 x 0.6mm) and 80 mAs (20 x 1.2 mm) representing screening low-dose, routine, narrow collimation and oncologic staging setups were measured with an Alderson-Rando phantom (Alderson Research Laboratories Inc.). Scans were performed on a 64-row MDCT (SOMATOM Sensation 64, Siemens) simulating the prone and supine positions with a constant voltage of 120 kV. Dose values (male/female) were 2.5/2.9, 3.8/4.2, 4.2/4.5 and 5.7/6.4 mSv for 30, 50 (20 x 1.2 and 64 x 0.6 mm) and 80 mAs, respectively. Measurements showed an elevated dose for females (11.5% mean; compared to males). Use of narrow collimation combined with 50 mAs resulted in a small increase of dose exposure of 10.5 (male) and 7.1% (female). Gonad doses ranged from 0.9 to 2.6 mSv (male) and from 1.5 to 3.5 mSv (female). In all protocols, the stomach wall, lower colon, urinary bladder and liver were slightly more highly exposed (all <2.3 mSv) than the other organs, and the breast dose was <0.3 mSv in every setup. Values of radiation exposure in 64- and 16-slice CTC differ only marginally when using the narrow collimation. In 64-slice CTC, the use of narrow (64 x 0.6 mm) collimation shows slightly elevated dose values compared to wider (20 x 1.2 mm) collimation. (orig.)

  20. Experimentally studied dynamic dose interplay does not meaningfully affect target dose in VMAT SBRT lung treatments.

    Science.gov (United States)

    Stambaugh, Cassandra; Nelms, Benjamin E; Dilling, Thomas; Stevens, Craig; Latifi, Kujtim; Zhang, Geoffrey; Moros, Eduardo; Feygelman, Vladimir

    2013-09-01

    The effects of respiratory motion on the tumor dose can be divided into the gradient and interplay effects. While the interplay effect is likely to average out over a large number of fractions, it may play a role in hypofractionated [stereotactic body radiation therapy (SBRT)] treatments. This subject has been extensively studied for intensity modulated radiation therapy but less so for volumetric modulated arc therapy (VMAT), particularly in application to hypofractionated regimens. Also, no experimental study has provided full four-dimensional (4D) dose reconstruction in this scenario. The authors demonstrate how a recently described motion perturbation method, with full 4D dose reconstruction, is applied to describe the gradient and interplay effects during VMAT lung SBRT treatments. VMAT dose delivered to a moving target in a patient can be reconstructed by applying perturbations to the treatment planning system-calculated static 3D dose. Ten SBRT patients treated with 6 MV VMAT beams in five fractions were selected. The target motion (motion kernel) was approximated by 3D rigid body translation, with the tumor centroids defined on the ten phases of the 4DCT. The motion was assumed to be periodic, with the period T being an average from the empirical 4DCT respiratory trace. The real observed tumor motion (total displacement ≤ 8 mm) was evaluated first. Then, the motion range was artificially increased to 2 or 3 cm. Finally, T was increased to 60 s. While not realistic, making T comparable to the delivery time elucidates if the interplay effect can be observed. For a single fraction, the authors quantified the interplay effect as the maximum difference in the target dosimetric indices, most importantly the near-minimum dose (D99%), between all possible starting phases. For the three- and five-fractions, statistical simulations were performed when substantial interplay was found. For the motion amplitudes and periods obtained from the 4DCT, the interplay effect

  1. Experimentally studied dynamic dose interplay does not meaningfully affect target dose in VMAT SBRT lung treatments

    International Nuclear Information System (INIS)

    Stambaugh, Cassandra; Nelms, Benjamin E.; Dilling, Thomas; Stevens, Craig; Latifi, Kujtim; Zhang, Geoffrey; Moros, Eduardo; Feygelman, Vladimir

    2013-01-01

    Purpose: The effects of respiratory motion on the tumor dose can be divided into the gradient and interplay effects. While the interplay effect is likely to average out over a large number of fractions, it may play a role in hypofractionated [stereotactic body radiation therapy (SBRT)] treatments. This subject has been extensively studied for intensity modulated radiation therapy but less so for volumetric modulated arc therapy (VMAT), particularly in application to hypofractionated regimens. Also, no experimental study has provided full four-dimensional (4D) dose reconstruction in this scenario. The authors demonstrate how a recently described motion perturbation method, with full 4D dose reconstruction, is applied to describe the gradient and interplay effects during VMAT lung SBRT treatments.Methods: VMAT dose delivered to a moving target in a patient can be reconstructed by applying perturbations to the treatment planning system-calculated static 3D dose. Ten SBRT patients treated with 6 MV VMAT beams in five fractions were selected. The target motion (motion kernel) was approximated by 3D rigid body translation, with the tumor centroids defined on the ten phases of the 4DCT. The motion was assumed to be periodic, with the period T being an average from the empirical 4DCT respiratory trace. The real observed tumor motion (total displacement ≤8 mm) was evaluated first. Then, the motion range was artificially increased to 2 or 3 cm. Finally, T was increased to 60 s. While not realistic, making T comparable to the delivery time elucidates if the interplay effect can be observed. For a single fraction, the authors quantified the interplay effect as the maximum difference in the target dosimetric indices, most importantly the near-minimum dose (D 99% ), between all possible starting phases. For the three- and five-fractions, statistical simulations were performed when substantial interplay was found.Results: For the motion amplitudes and periods obtained from the

  2. Evaluation of doses delivered during CT examination by different scanners for purposes of intercomparison and dose optimization

    International Nuclear Information System (INIS)

    Bashiru, Adam

    2017-07-01

    This research study was aimed at performing dosimetry intercomparison on different CT scanners in the diagnostic radiology departments of Korle-Bu Teaching Hospital (KBTH), Sweden Ghana Medical Center (SGMC) and Global Medical and Imaging Center (GMIC). Using the standard body phantom and integrated ion chamber technique volume computed tomography dose index (CTDIvol) and Dose-Length Product (DLPs) within the phantom were evaluated. The ion chamber technique was applied to two 16 slice Siemens and one Toshiba Aquilion one CT scanners. CTDIvol and DLP values for the standard body polymethyl methacrylate (PMMA) phantom were estimated and comparison made with corresponding console displayed values for accuracy and also to deduce a suitable method for optimization of patients and occupationally exposed worker doses. Effective doses were also calculated. An intra and inter institutional comparison of measured doses and console displayed doses were performed. Chest protocol at Automatic Exposure Control (AEC) was applied during the scanning of the phantom. Estimated CTDIvol values (mGy) were 17mGy, 24mGy and 13.1mGy for SGMC, GMIC and KBTH respectively. These values deviated from the console displayed values by 24.1%, 22.9% and 31.3% respectively. Similarly, estimated DLP values (mGy.cm) were 675mGy.cm,944mGy.cm and 419mGy.cm for SGMC, GMIC and KBTH respectively deviating from the console displayed values by 24.1%, 24.2% and 29% respectively. In terms of effective doses (E), the calculated E (mSv) values were 9.45mSv, 13.2mSv and 5.87mSv estimated from the DLPs from SGMC, GMIC and KBTH respectively using K, the anatomy-specific dose coefficient expressing effective dose normalized to DLP in a standard CT dosimetry phantom of 0.014 mSv mGy-1 cm-1. The estimated doses were compared to other selected international Dose Reference Levels (DRLs) and were within range. (au)

  3. Leprosy Post-Exposure Prophylaxis (LPEP) programme: Study protocol for evaluating the feasibility and impact on case detection rates of contact tracing and single dose rifampicin

    NARCIS (Netherlands)

    Barth-Jaeggi, T. (Tanja); Steinmann, P. (Peter); Mieras, L. (Liesbeth); W.H. van Brakel (Wim); J.H. Richardus (Jan Hendrik); Tiwari, A. (Anuj); Bratschi, M. (Martin); Cavaliero, A. (Arielle); Vander Plaetse, B. (Bart); Mirza, F. (Fareed); Aerts, A. (Ann)

    2016-01-01

    textabstractIntroduction: The reported number of new leprosy patients has barely changed in recent years. Thus, additional approaches or modifications to the current standard of passive case detection are needed to interrupt leprosy transmission. Large-scale clinical trials with single dose

  4. Treatment plan evaluation using dose-volume histogram (DVH) and spatial dose-volume histogram (zDVH)

    International Nuclear Information System (INIS)

    Cheng, C.-W.; Das, Indra J.

    1999-01-01

    Objective: The dose-volume histogram (DVH) has been accepted as a tool for treatment-plan evaluation. However, DVH lacks spatial information. A new concept, the z-dependent dose-volume histogram (zDVH), is presented as a supplement to the DVH in three-dimensional (3D) treatment planning to provide the spatial variation, as well as the size and magnitude of the different dose regions within a region of interest. Materials and Methods: Three-dimensional dose calculations were carried out with various plans for three disease sites: lung, breast, and prostate. DVHs were calculated for the entire volume. A zDVH is defined as a differential dose-volume histogram with respect to a computed tomographic (CT) slice position. In this study, zDVHs were calculated for each CT slice in the treatment field. DVHs and zDVHs were compared. Results: In the irradiation of lung, DVH calculation indicated that the treatment plan satisfied the dose-volume constraint placed on the lung and zDVH of the lung revealed that a sizable fraction of the lung centered about the central axis (CAX) received a significant dose, a situation that warranted a modification of the treatment plan due to the removal of one lung. In the irradiation of breast with tangential fields, the DVH showed that about 7% of the breast volume received at least 110% of the prescribed dose (PD) and about 11% of the breast received less than 98% PD. However, the zDVHs of the breast volume in each of seven planes showed the existence of high-dose regions of 34% and 15%, respectively, of the volume in the two caudal-most planes and cold spots of about 40% in the two cephalic planes. In the treatment planning of prostate, DVHs showed that about 15% of the bladder and 40% of the rectum received 102% PD, whereas about 30% of the bladder and 50% of the rectum received the full dose. Taking into account the hollow structure of both the bladder and the rectum, the dose-surface histograms (DSH) showed larger hot-spot volume, about

  5. Idaho National Engineering Laboratory historical dose evaluation: Volume 1

    International Nuclear Information System (INIS)

    Francis, S.J.

    1991-08-01

    The methodology and results are presented for an evaluation of potential radiation doses to a hypothetical individual who may have resided at an offsite location with the highest concentration of airborne radionuclides near the Idaho National Engineering Laboratory (INEL). Volume 1 contains a summary of methods and results. The years of INEL operations from 1952 to 1989 were evaluated. Radiation doses to an adult, child, and infant were estimated for both operational (annual) and episodic (short-term) airborne releases from INEL facilities. Atmospheric dispersion of operational releases was modeled using annual average meteorological conditions. Dispersion of episodic releases was generally modeled using actual hourly wind speed and direction data at the time of release. 50 refs., 23 figs., 10 tabs

  6. Evaluation of dose delivered to critical organs during pituitary radiation therapy

    International Nuclear Information System (INIS)

    Awoda, Marwa Elrashied Mohammed

    2017-12-01

    The selection of an appropriate energy in radiation therapy for tumor and the delivery adequate dose to the tumors to be treated, is very important during the radiation treatment planning. Also the dose received to critical organs surrounding the tumor has be considered. In addition, validation of treatment plan quality is important, so the purpose of this study was to evaluate the effect of teletherapy cobalt and 6MV linac energies on dose distribution for the pituitary gland tumors and dose delivered to critical organs surrounding the tumor. 10 patients with pituitary adenocarcinomas were selected. For treatment plans with three field technique, verdes and two lateral fields, were used. For the therapeutic area, five organs left and right eye lens left and right optic never and chasms and brain stem, were considered as Organ at risk (OARS). Several physical indices for for planning target volume (PTV) and the organs at risk 9 (OARS) as means dose (MD). 95%, dose (D950), 5% dose (D5) and normal tissue dose (NTID), were calculated, and the homogeneity index and conformity index were also two other evaluation parameters have been taken into account. The comparative evaluation was based on dose volume histogram ( DVH) analysis for both energies plans. After performing the treatment planning with two different energies the dose received to critical organs and dose distribution in PTV were studied. Results showed that the difference between the integral dose received to OARs with Co-60 and 6-MV linac respectively, 2.16±1.48, 1.85±1.55 for Lt eye lens. 3.01±2.52, 1.89±2.09 for Rt eye lens, 18.5±10.97, 19.43±10.65 for Lt optic nerve and chasms, 15.86±11.30, 17.44±15.73 for Rt optic nerve and chasms and 24.03±13.68, 23.77±16.64 for Brain stem case showed higher integral dose for linac than Co-60 than due to using the 6-MV energy as an open field with no beam modifiers such MLCs or shielding blocks. Eventually, it found that using of 6-MV linac provides better

  7. Evaluation of environmental radiation dose in Ibaraki Prefecture

    International Nuclear Information System (INIS)

    Koike, Ryoji

    1977-01-01

    In Ibaraki Prefecture, there is Environmental Radioactivity Surveillance Committee in order to ensure the safety around nuclear power facilities. Environmental radioactivity data are collected every three months, and the grasp of the present situation, the clarification of causes, the evaluation of dose and the publication of results are made. Two instances in particular are described: of contamination paddies due to 14 C contained in drainage; contamination of rivers due to U contained in drainage. (Mori, K.)

  8. Evaluation of occupational dose from the special procedures guided by fluoroscopy: cardiac catheterism

    International Nuclear Information System (INIS)

    Silva, Amanda Juliene da

    2011-01-01

    The purpose of this study was to evaluate the dose received by health professionals in the hemodynamic sector of a university hospital in Sao Paulo city. A self-applied questionnaire was used to delineate the profile of health professionals, taking into account sociodemographic variables and variables related to the work with ionizing radiation. The assessment of occupational doses was performed by consulting of the individual dose records of the institution database from 2000 to 2009. A total of 240 records was evaluated, corresponding to 38 active professionals (2009), divided in different professional category: physician, nurses, radiologic technologists and nursing assistants. The annual doses were compared with the limits established by national regulatory authorities. Based on the effective doses received and recorded during the studied period, experimental measures were performed with TL dosimeters in five physicians to evaluate the equivalent dose, in the left hand, during hemodynamic procedures. In addition, the radioprotection measures adopted by health professionals were verified. This study allowed delineating the profile of medical staff that integrates the hemodynamic service as well as knowing the distribution of their doses in relation to limits over the years. (author)

  9. Safety evaluation of combination toceranib phosphate (Palladia®) and piroxicam in tumour-bearing dogs (excluding mast cell tumours): a phase I dose-finding study.

    Science.gov (United States)

    Chon, E; McCartan, L; Kubicek, L N; Vail, D M

    2012-09-01

    Toceranib phosphate and piroxicam have individually demonstrated antineoplastic activity. Additionally, non-steroidal anti-inflammatory therapy is often warranted in aged cancer-bearing dogs for management of osteoarthritis comorbidity. As concurrent use may be warranted for a given individual and the adverse event (AE) profile for each can be overlapping (gastrointestinal), a phase I trial was performed in tumour-bearing (non-mast cell) dogs to establish the safety of the combination using a standard 3+3 cohort design. Five dose-escalating cohorts, up to and including approved label dosage for toceranib and standard dosage for piroxicam, were completed without observing a frequency of dose-limiting AEs necessitating cohort closure. Therefore, the combination of standard dosages of both drugs (toceranib, 3.25 mg kg(-1), every other day; piroxicam, 0.3 mg kg(-1) daily) is generally safe. Several antitumour responses were observed. As with single-agent toceranib, label-indicated treatment holidays and dose reductions (e.g. 2.5-2.75 mg kg(-1)) may occasionally be required owing to gastrointestinal events. © 2011 Blackwell Publishing Ltd.

  10. Evaluation of a High Concentrated Contrast Media Injection Protocol in Combination with Low Tube Current for Dose Reduction in Coronary Computed Tomography Angiography: A Randomized, Two-center Prospective Study.

    Science.gov (United States)

    Sun, Yibo; Hua, Yanqing; Wang, Mingpeng; Mao, Dingbiao; Jin, Xiu; Li, Cheng; Shi, Kailei; Xu, Jianrong

    2017-12-01

    The study aimed to prospectively evaluate the radiation dose reduction potential and image quality (IQ) of a high-concentration contrast media (HCCM) injection protocol in combination with a low tube current (mAs) in coronary computed tomography angiography. Eighty-one consecutive patients (mean age: 62 years; 34 females; body mass index: 18-31) were included and randomized-assigned into two groups. All computed tomography (CT) examinations were performed in two groups with the same tube voltage (100 kV), flow rate of contrast medium (5.0 mL/s), and iodine dose (22.8 g). An automatic mAs and low concentration contrast medium (300 mgI/mL) were used in group A, whereas effective mAs was reduced by a factor 0.6 along with HCCM (400 mgI/mL) in group B. Radiation dose was assessed (CT dose index [CTDI vol ] and dose length product), and vessel-based objective IQ for various regions of interest (enhancement, noise, signal-to-noise ratio, and contrast-to-noise ratio), subjective IQ, noise, and motion artifacts were analyzed overall and vessel-based with a 5-point Likert scale. The CT attenuation of coronary arteries and image noise in group B were significantly higher than those in group A (ranges: 507.5-548.1 Hounsfield units vs 407.5-444.5 Hounsfield units; and 20.3 ± 8.6 vs 17.7 ± 8.0) (P ≤ 0.0166). There was no significant difference between the two groups in signal-to-noise ratio, contrast-to-noise ratio, and subjective IQ of coronary arteries (29.4-31.7, 30.0-37.0, and medium score of 5 in group A vs 29.4-32.4, 27.7-36.3, and medium score of 5 in group B, respectively, P ≥ 0.1859). Both mean CTDI vol and dose length product in group B were 58% of those of group A. HCCM combined with low tube current allows dose reduction in coronary computed tomography angiography and does not compromise IQ. Copyright © 2017 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.

  11. Evaluation of general-purpose collimators against high-resolution collimators with resolution recovery with a view to reducing radiation dose in myocardial perfusion SPECT: A preliminary phantom study.

    Science.gov (United States)

    Armstrong, Ian S; Saint, Kimberley J; Tonge, Christine M; Arumugam, Parthiban

    2017-04-01

    There is a growing focus on reducing radiation dose to patients undergoing myocardial perfusion imaging. This preliminary phantom study aims to evaluate the use of general-purpose collimators with resolution recovery (RR) to allow a reduction in patient radiation dose. Images of a cardiac torso phantom with inferior and anterior wall defects were acquired on a GE Infinia and Siemens Symbia T6 using both high-resolution and general-purpose collimators. Imaging time, a surrogate for administered activity, was reduced between 35% and 40% with general-purpose collimators to match the counts acquired with high-resolution collimators. Images were reconstructed with RR with and without attenuation correction. Two pixel sizes were also investigated. Defect contrast was measured. Defect contrast on general-purpose images was superior or comparable to the high-resolution collimators on both systems despite the reduced imaging time. Infinia general-purpose images required a smaller pixel size to be used to maintain defect contrast, while Symbia T6 general-purpose images did not require a change in pixel size to that used for standard myocardial perfusion SPECT. This study suggests that general-purpose collimators with RR offer a potential for substantial dose reductions while providing similar or better image quality to images acquired using high-resolution collimators.

  12. Evaluation of the repeated-dose liver micronucleus assay using N-nitrosomorpholine in young adult rats: report on collaborative study by the Collaborative Study Group for the Micronucleus Test (CSGMT)/Japanese Environmental Mutagen Society (JEMS)-Mammalian Mutagenicity Study (MMS) Group.

    Science.gov (United States)

    Hayashi, Aya; Kosaka, Mizuki; Kimura, Aoi; Wako, Yumi; Kawasako, Kazufumi; Hamada, Shuichi

    2015-03-01

    The present study was conducted to evaluate the suitability of a repeated-dose liver micronucleus (LMN) assay in young adult rats as a collaborative study by the Mammalian mutagenicity study (MMS) group. All procedures were performed in accordance with the standard protocols of the MMS Group. Six-week-old male Crl:CD(SD) rats (5 animals/group) received oral doses of the hepatocarcinogen N-nitrosomorpholine (NMOR) at 0 (control), 5, 10, and 30mg/kg/day (10mL/kg) for 14 days. Control animals received vehicle (water). Hepatocytes were collected from the liver 24h after the last dose, and the number of micronucleated hepatocytes (MNHEPs) was determined by microscopy. The number of micronucleated immature erythrocytes (MNIMEs) in the femoral bone marrow was also determined. The liver was examined using histopathologic methods after formalin fixation. The results showed statistically significant and dose-dependent increases in the number of MNHEPs in the liver at doses of 10mg/kg and greater when compared with the vehicle control. However, no significant increase was noted in the number of MNIMEs in the bone marrow at doses of up to 30mg/kg. Histopathology of the liver revealed hypertrophy and single cell necrosis of hepatocytes at doses of 5mg/kg and above. These results showed that the induction of micronuclei by NMOR was detected by the repeated-dose LMN assay, but not by the repeated-dose bone marrow micronucleus assay. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. Evaluation of the occupational doses of interventional radiologists

    NARCIS (Netherlands)

    Kuipers, Gerritjan; Velders, Xandra L.; de Winter, Robbert J.; Reekers, Jim A.; Piek, Jan J.

    2008-01-01

    The aim of the present study was to determine whether there is a linear relation between the doses measured above and those measured under the lead apron of the radiologists performing interventional procedures. To monitor radiation exposure the International Commission of Radiological Protection

  14. 4. Evaluation of the quality of fixed dose combination anti ...

    African Journals Online (AJOL)

    Esem

    Methodology: This was a cross sectional study whose objective was to determine the quality of 3 types of fixed dose combination (FDC) anti TB drugs namely 4FDC, 3FDC and 2FDC tablets available in Lusaka District by assessing the presence of active ingredients and the percentage content of these active ingredients ...

  15. Evaluation of dose according to the volume and respiratory range during SBRT in lung cancer

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Deuk Hee [Dept. of Radiation Oncology, Busan Paik Hospital, Inje University, Busan (Korea, Republic of); Park, Eun Tae; Kim, Jung Hoon; Kang, Se Seik [Dept. of Radiological Science, College of Health Sciences, Catholic University of Pusan, Busan (Korea, Republic of)

    2016-09-15

    Stereotactic body radiotherapy is effective technic in radiotherapy for low stage lung cancer. But lung cancer is affected by respiratory so accurately concentrate high dose to the target is very difficult. In this study, evaluated the target volume according to how to take the image. And evaluated the dose by photoluminescence glass dosimeter according to how to contour the volume and respiratory range. As a result, evaluated the 4D CT volume was 10.4 cm{sup 3} which was closest value of real size target. And in dose case is internal target volume dose was 10.82, 16.88, 21.90 Gy when prescribed dose was 10, 15, 20 Gy and it was the highest dose. Respiratory gated radiotherapy dose was more higher than internal target volume. But it made little difference by respiratory range. Therefore, when moving cancer treatment, acquiring image by 4D CT, contouring internal target volume and respiratory gated radiotherapy technic would be the best way.

  16. Evaluation of dose according to the volume and respiratory range during SBRT in lung cancer

    International Nuclear Information System (INIS)

    Lee, Deuk Hee; Park, Eun Tae; Kim, Jung Hoon; Kang, Se Seik

    2016-01-01

    Stereotactic body radiotherapy is effective technic in radiotherapy for low stage lung cancer. But lung cancer is affected by respiratory so accurately concentrate high dose to the target is very difficult. In this study, evaluated the target volume according to how to take the image. And evaluated the dose by photoluminescence glass dosimeter according to how to contour the volume and respiratory range. As a result, evaluated the 4D CT volume was 10.4 cm 3 which was closest value of real size target. And in dose case is internal target volume dose was 10.82, 16.88, 21.90 Gy when prescribed dose was 10, 15, 20 Gy and it was the highest dose. Respiratory gated radiotherapy dose was more higher than internal target volume. But it made little difference by respiratory range. Therefore, when moving cancer treatment, acquiring image by 4D CT, contouring internal target volume and respiratory gated radiotherapy technic would be the best way

  17. 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

  18. Final Technical Report. A critical evaluation of patent doses in screening mammography

    International Nuclear Information System (INIS)

    Hintenlang, David E.

    2004-01-01

    This project was designed to develop tools that would permit an accurate assessment of the patient doses that are received in screening mammography, and to subsequently demonstrate those tools to perform an objective evaluation of patient doses. The project also provides an educational component through the integration of multiple aspects of applied radiological engineering to provide students with realistic applications of many of the theoretical principles that are studied as part of their graduate curriculum

  19. Potential influence of new doses of A-bomb after re-evaluation of epidemiological research

    International Nuclear Information System (INIS)

    Maruyama, T.

    1983-01-01

    Since the peaceful use of atomic energy appears essential for future human existence, we must provide risk estimates from low-dose exposures to human beings. The largest body of human data has been derived from the studies of atomic bomb survivors in Hiroshima and Nagasaki. Recently, it was proposed by an Oak Ridge National Laboratory group that the current free-in-air doses of atomic bombs are significantly different from the doses recalculated on the basis of the new output spectra of neutrons and gamma rays from the atomic bombs which were declassified by the US Department of Energy in 1976. A joint commission on dose re-evaluation of the United States of America and Japan was established in 1981 to pursue the dose reassessment programme between US and Japanese research groups and to decide an agreed best estimate of organ or tissue doses in survivors as soon as possible. The paper reviews the physical concepts of the re-evaluation of atomic bomb doses and discusses the potential influence of new dosimetric parameters on the epidemiological studies of the atomic bomb survivors in future, although the re-assessment programme is still in progress. (author)

  20. Methods to verify absorbed dose of irradiated containers and evaluation of dosimeters

    International Nuclear Information System (INIS)

    Gao Meixu; Wang Chuanyao; Tang Zhangxong; Li Shurong

    2001-01-01

    The research on dose distribution in irradiated food containers and evaluation of several methods to verify absorbed dose were carried out. The minimum absorbed dose of treated five orange containers was in the top of the highest or in the bottom of lowest container. D max /D min in this study was 1.45 irradiated in a commercial 60 Co facility. The density of orange containers was about 0.391g/cm 3 . The evaluation of dosimeters showed that the PMMA-YL and clear PMMA dosimeters have linear relationship with dose response, and the word NOT in STERIN-125 and STERIN-300 indicators were covered completely at the dosage of 125 and 300 Gy respectively. (author)

  1. A prospective evaluation of hippocampal radiation dose volume effects and memory deficits following cranial irradiation.

    Science.gov (United States)

    Ma, Ting Martin; Grimm, Jimm; McIntyre, Riley; Anderson-Keightly, Heather; Kleinberg, Lawrence R; Hales, Russell K; Moore, Joseph; Vannorsdall, Tracy; Redmond, Kristin J

    2017-11-01

    To prospectively evaluate hippocampal radiation dose volume effects and memory decline following cranial irradiation. Effects of hippocampal radiation over a wide range of doses were investigated by combining data from three prospective studies. In one, adults with small cell lung cancer received hippocampal-avoidance prophylactic cranial irradiation. In the other two, adults with glioblastoma multiforme received neural progenitor cell sparing radiation or no sparing with extra dose delivered to subventricular zone. Memory was measured by the Hopkins Verbal Learning Test-Revised Delayed Recall (HVLT-R DR) at 6 months after radiation. Dose-volume histograms were generated and dose-response data were fitted to a nonlinear model. Of 60 patients enrolled, 30 were analyzable based on HVLT-R DR testing completion status, baseline HVLT-R DR and intracranial metastasis/recurrence or prior hippocampal resection status. We observed a dose-response of radiation to the hippocampus with regard to decline in HVLT-R DR. D50% of the bilateral hippocampi of 22.1 Gy is associated with 20% risk of decline. This prospective study demonstrates an association between hippocampal dose volume effects and memory decline measured by HVLT-R DR over a wide dose range. These data support a potential benefit of hippocampal sparing and encourage continued trial enrollment. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Radiation dose evaluation in patients submitted to conventional radiological examinations

    International Nuclear Information System (INIS)

    Tilly Junior, Joao G.

    1997-01-01

    This work presents the results of the evaluation of radiation dose delivered to the patients undergoing conventional radiological procedures. Based in the realized measurement some indicators are settled to quantitative appraisal of the radiological protection conditions offered to the population. Data assessment was done in the county of Curitiba, in Parana State, Brazil, from 12/95 to 04/96, in ten rooms of three different institutions, under 101 patients, adults with 70 ± 10 kg, during real examinations of chest PA, chest LAT and abdomen AP. (author)

  3. A study on gamma dose rate in Seoul (I)

    International Nuclear Information System (INIS)

    Kim, You Hyun; Kim, Chang Kyun; Choi, Jong Hak; Kim, Jeong Min

    2001-01-01

    This study was conducted to find out gamma dose rate in Seoul, from January to December in 2000, and the following results were achieved : The annual gamma dose rate in Seoul was 17.24 μR/hr as average. The annual gamma dose rate in subway of Seoul was 14.96 μR/hr as average. The highest annual gamma dose rate was Dong-daemon ku. Annual gamma dose rate in Seoul was higher autumn than winter

  4. Extracranial stereotactic radiotherapy: Evaluation of PTV coverage and dose conformity

    International Nuclear Information System (INIS)

    Haedinger, U.; Thiele, W.; Wulf, J.

    2002-01-01

    During the past few years the concept of cranial sterotactic radiotherapy has been successfully extended to extracranial tumoral targets. In our department, hypofractionated treatment of tumours in lung, liver, abdomen, and pelvis is performed in the Stereotactic Body Frame (ELEKTA Instrument AB) since 1997. We present the evaluation of 63 consecutively treated targets (22 lung, 21 liver, 20 abdomen/pelvis) in 58 patients with respect to dose coverage of the planning target volume (PTV) as well as conformity of the dose distribution. The mean PTV coverage was found to be 96.3%±2.3% (lung), 95.0%±4.5% (liver), and 92.1%±5.2% (abdomen/pelvis). For the so-called conformation number we obtained values of 0.73±0.09 (lung), 0.77±0.10 (liver), and 0.70±0.08 (abdomen/pelvis). The results show that highly conformal treatment techniques can be applied also in extracranial stereotactic radiotherapy. This is primarily due to the relatively simple geometrical shape of most of the targets. Especially lung and liver targets turned out to be approximately spherically/cylindrically shaped, so that the dose distribution can be easily tailored by rotational fields. (orig.) [de

  5. Dose evaluation of three-dimensional small animal phantom with film dosimetry

    International Nuclear Information System (INIS)

    Han, Su Chul; Park, Seung Woo

    2017-01-01

    The weight of small animal dosimetry has been continuously increased in pre-clinical studies using radiation in small animals. In this study, three-dimensional(3D) small animal phantom was fabricated using 3D printer which has been continuously used and studied in the various fields. The absorbed dose of 3D animal phantom was evaluated by film dosimetry. Previously, the response of film was obtained from the materials used for production of 3D small animal phantom and compared with the bolus used as the tissue equivalent material in the radiotherapy. When irradiated with gamma rays from 0.5 Gy to 6 Gy, it was confirmed that there was a small difference of less than 1% except 0.5 Gy dose. And when small animal phantom was irradiated with 5 Gy, the difference between the irradiated dose and calculated dose from film was within 2%. Based on this study, it would be possible to increase the reliability of dose in pre-clinical studies using irradiation in small animals by evaluating dose of 3D small animal phantom

  6. Dose evaluation of three-dimensional small animal phantom with film dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Han, Su Chul [Div. of Medical Radiation Equipment, Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of); Park, Seung Woo [Radilogcial and Medico-Oncological Sciences, University of Sciences and Technology, Daejeon (Korea, Republic of)

    2017-03-15

    The weight of small animal dosimetry has been continuously increased in pre-clinical studies using radiation in small animals. In this study, three-dimensional(3D) small animal phantom was fabricated using 3D printer which has been continuously used and studied in the various fields. The absorbed dose of 3D animal phantom was evaluated by film dosimetry. Previously, the response of film was obtained from the materials used for production of 3D small animal phantom and compared with the bolus used as the tissue equivalent material in the radiotherapy. When irradiated with gamma rays from 0.5 Gy to 6 Gy, it was confirmed that there was a small difference of less than 1% except 0.5 Gy dose. And when small animal phantom was irradiated with 5 Gy, the difference between the irradiated dose and calculated dose from film was within 2%. Based on this study, it would be possible to increase the reliability of dose in pre-clinical studies using irradiation in small animals by evaluating dose of 3D small animal phantom.

  7. Scalp Dose Evaluation According Radiation Therapy Technique of Whole Brain Radiation Therapy

    International Nuclear Information System (INIS)

    Jang, Joon Yung; Park, Soo Yun; Kim, Jong Sik; Choi, Byeong Gi; Song, Gi Won

    2011-01-01

    Opposing portal irradiation with helmet field shape that has been given to a patient with brain metastasis can cause excess dose in patient's scalp, resulting in hair loss. For this reason, this study is to quantitatively analyze scalp dose for effective prevention of hair loss by comparing opposing portal irradiation with scalp-shielding shape and tomotherapy designed to protect patient's scalp with conventional radiation therapy. Scalp dose was measured by using three therapies (HELMET, MLC, TOMO) after five thermo-luminescence dosimeters were positioned along center line of frontal lobe by using RANDO Phantom. Scalp dose and change in dose distribution were compared and analyzed with DVH after radiation therapy plan was made by using Radiation Treatment Planning System (Pinnacle3, Philips Medical System, USA) and 6 MV X-ray (Clinac 6EX, VARIAN, USA). When surface dose of scalp by using thermo-luminescence dosimeters was measured, it was revealed that scalp dose decreased by average 87.44% at each point in MLC technique and that scalp dose decreased by average 88.03% at each point in TOMO compared with HELMET field therapy. In addition, when percentage of volume (V95%, V100%, V105% of prescribed dose) was calculated by using Dose Volume Histogram (DVH) in order to evaluate the existence or nonexistence of hotspot in scalp as to three therapies (HELMET, MLC, TOMO), it was revealed that MLC technique and TOMO plan had good dose coverage and did not have hot spot. Reducing hair loss of a patient who receives whole brain radiotherapy treatment can make a contribution to improve life quality of the patient. It is expected that making good use of opposing portal irradiation with scalp-shielding shape and tomotherapy to protect scalp of a patient based on this study will reduce hair loss of a patient.

  8. Scalp Dose Evaluation According Radiation Therapy Technique of Whole Brain Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Joon Yung; Park, Soo Yun; Kim, Jong Sik; Choi, Byeong Gi; Song, Gi Won [Dept. of Radiation Oncology, Samsung Medical Center, Seoul (Korea, Republic of)

    2011-09-15

    Opposing portal irradiation with helmet field shape that has been given to a patient with brain metastasis can cause excess dose in patient's scalp, resulting in hair loss. For this reason, this study is to quantitatively analyze scalp dose for effective prevention of hair loss by comparing opposing portal irradiation with scalp-shielding shape and tomotherapy designed to protect patient's scalp with conventional radiation therapy. Scalp dose was measured by using three therapies (HELMET, MLC, TOMO) after five thermo-luminescence dosimeters were positioned along center line of frontal lobe by using RANDO Phantom. Scalp dose and change in dose distribution were compared and analyzed with DVH after radiation therapy plan was made by using Radiation Treatment Planning System (Pinnacle3, Philips Medical System, USA) and 6 MV X-ray (Clinac 6EX, VARIAN, USA). When surface dose of scalp by using thermo-luminescence dosimeters was measured, it was revealed that scalp dose decreased by average 87.44% at each point in MLC technique and that scalp dose decreased by average 88.03% at each point in TOMO compared with HELMET field therapy. In addition, when percentage of volume (V95%, V100%, V105% of prescribed dose) was calculated by using Dose Volume Histogram (DVH) in order to evaluate the existence or nonexistence of hotspot in scalp as to three therapies (HELMET, MLC, TOMO), it was revealed that MLC technique and TOMO plan had good dose coverage and did not have hot spot. Reducing hair loss of a patient who receives whole brain radiotherapy treatment can make a contribution to improve life quality of the patient. It is expected that making good use of opposing portal irradiation with scalp-shielding shape and tomotherapy to protect scalp of a patient based on this study will reduce hair loss of a patient.

  9. Characteristics of 3D gamma evaluation according to phantom rotation error and dose gradient

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kyeong Hyun; Kim, Dong Su; Kim, Tae Ho; Kang, Seong Hee; Shin, Dong Seok; Noh, Yu Yoon; Suh, Tae Seok [Dept. of Biomedical Engineering, Research Institute of Biomedical Engineering, College of Medicine, the Catholic University of Korea, Seoul (Korea, Republic of); Cho, Min Seok [Dept. of Radiation Oncology, Asan Medical Center, Seoul (Korea, Republic of)

    2016-12-15

    In intensity modulated radiation therapy (IMRT) quality assurance (QA) using dosimetric phantom, a spatial uncertainty induced from phantom set-up inevitably occurs and gamma index that is used to evaluate IMRT plan quality can be affected differently by a combination of the spatial uncertainty and magnitude of dose gradient. In this study, we investigated the impacts of dose gradient and the phantom set-up error on 3D gamma evaluation. In this study, we investigated the characteristics of gamma evaluation according to dose gradient and phantom rotation axis. As a result, 3D gamma had better performance than 2D gamma. Therefore, it can be useful for IMRT QA analysis at clinical field.

  10. Effective dose evaluation of NORM-added consumer products using Monte Carlo simulations and the ICRP computational human phantoms

    International Nuclear Information System (INIS)

    Lee, Hyun Cheol; Yoo, Do Hyeon; Testa, Mauro; Shin, Wook-Geun; Choi, Hyun Joon; Ha, Wi-Ho; Yoo, Jaeryong; Yoon, Seokwon; Min, Chul Hee

    2016-01-01

    The aim of this study is to evaluate the potential hazard of naturally occurring radioactive material (NORM) added consumer products. Using the Monte Carlo method, the radioactive products were simulated with ICRP reference phantom and the organ doses were calculated with the usage scenario. Finally, the annual effective doses were evaluated as lower than the public dose limit of 1 mSv y"−"1 for 44 products. It was demonstrated that NORM-added consumer products could be quantitatively assessed for the safety regulation. - Highlights: • Consumer products considered that NORM would be included should be regulated. • 44 products were collected and its gamma activities were measured with HPGe detector. • Through Monte Carlo simulation, organ equivalent doses and effective doses on human phantom were calculated. • All annual effective doses for the products were evaluated as lower than dose limit for the public.

  11. Evaluation of medium-dose UVA1 phototherapy in localized scleroderma with the cutometer and fast Fourier transform method

    NARCIS (Netherlands)

    de Rie, M. A.; Enomoto, D. N. H.; de Vries, H. J. C.; Bos, J. D.

    2003-01-01

    Purpose: To evaluate the efficacy of medium-dose UVA1 phototherapy in patients with localized scleroderma. Method: A controlled pilot study with medium-dose UVA1 (48 J/cm(2)) was performed. The results were evaluated by means of a skin score and two objective methods for quantifying sclerosis

  12. Dose area product evaluations with Gafchromic XR-R films and a flat-bed scanner.

    Science.gov (United States)

    Rampado, O; Garelli, E; Deagostini, S; Ropolo, R

    2006-12-07

    Gafchromic XR-R films are a useful tool to evaluate entrance skin dose in interventional radiology. Another dosimetric quantity of interest in diagnostic and interventional radiology is the dose area product (DAP). In this study, a method to evaluate DAP using Gafchromic XR-R films and a flat-bed scanner was developed and tested. Film samples were exposed to an x-ray beam of 80 kVp over a dose range of 0-10 Gy. DAP measurements with films were obtained from the digitalization of a film sample positioned over the x-ray beam window during the exposure. DAP values obtained with this method were compared for 23 cardiological interventional procedures with DAP values displayed by the equipment. The overall one-sigma dose measurement uncertainty depended on the absorbed dose, with values below 6% for doses above 1 Gy. A maximum discrepancy of 16% was found, which is of the order of the differences in the DAP measurements that may occur with different calibration procedures. Based on the results presented, after an accurate calibration procedure and a thorough inspection of the relationship between the actual dose and the direct measured quantity (net optical density or net pixel value variation), Gafchromic XR-R films can be used to assess the DAP.

  13. Phase 2, Randomized, Double-Blind, Dose-Ranging Study Evaluating the Safety, Tolerability, Population Pharmacokinetics, and Efficacy of Oral Torezolid Phosphate in Patients with Complicated Skin and Skin Structure Infections▿ † ‡

    Science.gov (United States)

    Prokocimer, P.; Bien, P.; Surber, J.; Mehra, P.; DeAnda, C.; Bulitta, J. B.; Corey, G. R.

    2011-01-01

    Torezolid (TR-700) is the active moiety of the prodrug torezolid phosphate ([TP] TR-701), a second-generation oxazolidinone with 4- to 16-fold greater potency than linezolid against Gram-positive species including methicillin-resistant Staphylococcus aureus (MRSA). A double-blind phase 2 study evaluated three levels (200, 300, or 400 mg) of oral, once-daily TP over 5 to 7 days for complicated skin and skin structure infections (cSSSI). Patients 18 to 75 years old with cSSSI caused by suspected or confirmed Gram-positive pathogens were randomized 1:1:1. Of 188 treated patients, 76.6% had abscesses, 17.6% had extensive cellulitis, and 5.9% had wound infections. S. aureus, the most common pathogen, was isolated in 90.3% of patients (139/154) with a baseline pathogen; 80.6% were MRSA. Cure rates in clinically evaluable patients were 98.2% at 200 mg, 94.4% at 300 mg, and 94.4% at 400 mg. Cure rates were consistent across diagnoses, regardless of lesion size or the presence of systemic signs of infection. Clinical cure rates in patients with S. aureus isolated at baseline were 96.6% overall and 96.8% for MRSA. TP was safe and well tolerated at all dose levels. No patients discontinued treatment due to an adverse event. Three-stage hierarchical population pharmacokinetic modeling yielded a geometric mean clearance of 8.28 liters/h (between-patient variability, 32.3%), a volume of the central compartment of 71.4 liters (24.0%), and a volume of the peripheral compartment of 27.9 liters (35.7%). Results of this study show a high degree of efficacy at all three dose levels without significant differences in the safety profile and support the continued evaluation of TP for the treatment of cSSSI in phase 3 trials. PMID:21115795

  14. Analysis and planning of dose-finding studies with active control

    International Nuclear Information System (INIS)

    Helms, Hans-Joachim

    2014-01-01

    In the clinical development of radiopharmaceuticals the dose finding plays an important role. The contribution is focused on the evaluation and planning of dose finding studies with active control. It is of primary interest to find the lowest dose that yields the same efficacy as the active control. Besides the target dose confidence intervals are of importance to describe the quality of the target dose estimation. The calculation of case numbers and the determination of the dose steps to be studied are challenging under practical conditions. The contribution covers the demonstration of the statistical model the parameter estimation and the asymptotic properties based on maximum likelihood theory, the spline-based evaluation of nonlinear dose finding studies with active control and the planning of design and number of cases.

  15. Evaluation of patient radiation doses using DAP meter in interventional radiology procedures

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Byung Sam [Dept. of Radiological Technology. Shingu University, Sungnam (Korea, Republic of); Yoon, Yong Su [Dept. of Health Sciences, Graduate School of Medical Sciences, Kyushu Univeristy, Kyushu (Japan)

    2017-03-15

    The author investigated interventional radiology patient doses in several other countries, assessed accuracy of DAP meters embedded in intervention equipment in domestic country, conducted measurement of patient doses for 13 major interventional procedures with use of Dose Area Product(DAP) meters from 23 hospitals in Korea, and referred to 8,415 cases of domestic data related to interventional procedures by radiation exposure after evaluation the actual effective of dose reduction variables through phantom test. Finally, dose reference level for major interventional procedures was suggested. In this study, guidelines for patient doses were 237.7 Gy·cm{sup 2} in TACE, 17.3 Gy·cm{sup 2} in AVF, 114.1 Gy·cm{sup 2} in LE PTA and STENT, 188.5 Gy·cm{sup 2} in TFCA, 383.5 Gy·cm{sup 2} in Aneurysm Coil, 64.6 Gy·cm{sup 2} in PTBD, 64.6 Gy·cm{sup 2} in Biliary Stent, 22.4 Gy·cm{sup 2} in PCN, 4.3 Gy·cm{sup 2} in Hickman, 2.8 Gy·cm{sup 2} in Chemo-port, 4.4 Gy·cm{sup 2} in Perm-Cather, 17.1 Gy·cm{sup 2} in PCD, and 357.9 Gy·cm{sup 2} in Vis, EMB. Dose reference level acquired in this study is considered to be able to use as minimal guidelines for reducing patient dose in the interventional radiology procedures. For the changes and advances of materials and development of equipment and procedures in the interventional radiology procedures, further studies and monitoring are needed on dose reference level Korean DAP dose conversion factor for the domestic procedures.

  16. Review of low dose-rate epidemiological studies and biological mechanisms of dose-rate effects on radiation induced carcinogenesis

    International Nuclear Information System (INIS)

    Iwasaki, Toshiyasu; Otsuka, Kensuke; Yoshida, Kazuo

    2015-01-01

    Radiation protection system adopts the linear non-threshold model with using dose and dose-rate effectiveness factor (DDREF). The dose-rate range where DDREF is applied is below 100 mGy per hour, and it is regarded that there are no dose-rate effects at very low dose rate, less than of the order of 10 mGy per year, even from the biological risk evaluation model based on cellular and molecular level mechanisms for maintenance of genetic integrity. Among low dose-rate epidemiological studies, studies of residents in high natural background areas showed no increase of cancer risks at less than about 10 mGy per year. On the other hand, some studies include a study of the Techa River cohort suggested the increase of cancer risks to the similar degree of Atomic bomb survivor data. The difference of those results was supposed due to the difference of dose rate. In 2014, International Commission on Radiological Protection opened a draft report on stem cell biology for public consultations. The report proposed a hypothesis based on the new idea of stem cell competition as a tissue level quality control mechanism, and suggested that it could explain the dose-rate effects around a few milligray per year. To verify this hypothesis, it would be needed to clarify the existence and the lowest dose of radiation-induced stem cell competition, and to elucidate the rate of stem cell turnover and radiation effects on it. As for the turnover, replenishment of damaged stem cells would be the important biological process. It would be meaningful to collect the information to show the difference of dose rates where the competition and the replenishment would be the predominant processes. (author)

  17. Estimate of dose in interventional radiology: a study of cases

    International Nuclear Information System (INIS)

    Pinto, N.; Braz, D.; Lopes, R.; Vallim, M.; Padilha, L.; Azevedo, F.; Barroso, R.

    2006-01-01

    Values of absorbed dose taken by patients and professionals involved in interventional radiology can be significant mainly for the reason of these proceedings taking long time of fluoroscopy There are many methods to estimate and reduce doses of radiation in the interventional radiology, particularly because the fluoroscopy is responsible for the high dose contribution in the patient and in the professional. The aim of this work is the thermoluminescent dosimetry to estimate the dose values of the extremities of the professionals involved in the interventional radiology and the product dose-area was investigated using a Diamentor. This evaluation is particularly useful for proceedings that interest multiple parts of the organism. In this study were used thermoluminescent dosimeters (LiF:Mg, Ti - Harshaw) to estimate the dose values of the extremities of the professionals and to calibrate them. They were irradiated with X rays at 50 mGy, in Kerma in air and read in the reader Harshaw-5500. The product dose-area (D.A.P.) were obtained through the Diamentor (M2-P.T.W.) calibrated in Cgy.cm 2 fixed in the exit of the X-rays tube. The patients of these study were divided in three groups: individuals submitted to proceedings of embolization, individuals submitted to cerebral and renal arteriography and individuals submitted to proceedings of Transjungular Inthahepatic Porta Systemic Stent Shunt (TIPS). The texts were always carried out by the same group: radiologist doctor), an auxiliary doctor and a nursing auxiliary. The section of interventional radiology has an Angiostar Plus Siemens equipment type arc C, in which there is trifocal Megalix X-ray tube and a intensifier of image from Sirecon 40-4 HDR/33 HDR. In this work the dose estimated values were 137.25 mSv/year for the doctors, 40.27 mSv/year for the nursing and 51.95 mSv/year for the auxiliary doctor and they are below the rule, but in this study it was not taken in consideration the emergency texts as they were

  18. SU-E-T-67: Clinical Implementation and Evaluation of the Acuros Dose Calculation Algorithm

    International Nuclear Information System (INIS)

    Yan, C; Combine, T; Dickens, K; Wynn, R; Pavord, D; Huq, M

    2014-01-01

    Purpose: The main aim of the current study is to present a detailed description of the implementation of the Acuros XB Dose Calculation Algorithm, and subsequently evaluate its clinical impacts by comparing it with AAA algorithm. Methods: The source models for both Acuros XB and AAA were configured by importing the same measured beam data into Eclipse treatment planning system. Both algorithms were evaluated by comparing calculated dose with measured dose on a homogeneous water phantom for field sizes ranging from 6cm × 6cm to 40cm × 40cm. Central axis and off-axis points with different depths were chosen for the comparison. Similarly, wedge fields with wedge angles from 15 to 60 degree were used. In addition, variable field sizes for a heterogeneous phantom were used to evaluate the Acuros algorithm. Finally, both Acuros and AAA were tested on VMAT patient plans for various sites. Does distributions and calculation time were compared. Results: On average, computation time is reduced by at least 50% by Acuros XB compared with AAA on single fields and VMAT plans. When used for open 6MV photon beams on homogeneous water phantom, both Acuros XB and AAA calculated doses were within 1% of measurement. For 23 MV photon beams, the calculated doses were within 1.5% of measured doses for Acuros XB and 2% for AAA. When heterogeneous phantom was used, Acuros XB also improved on accuracy. Conclusion: Compared with AAA, Acuros XB can improve accuracy while significantly reduce computation time for VMAT plans

  19. Pediatric and staff dose evaluation in fluoroscopy upper gastrointestinal series

    Energy Technology Data Exchange (ETDEWEB)

    Filipov, Danielle; Nascimento, Eduarda X. do; Lacerda, Camila M., E-mail: diilipov@utfpr.edu.br [Universidade Tecnologica Federal do Parana (UFTPR), Curitiba, PR (Brazil); Schelin, Hugo R.; Ledesma, Jorge A.; Denyak, Valeriy; Legnani, Adriano, E-mail: ledesmajorgealberto@gmail.com [Instituto de Pesquisa Pele Pequeno Principe, Curitiba, PR (Brazil)

    2014-07-01

    Fluoroscopy upper GI series are widely used for the diagnosis of gastroesophageal reflux disease in children. Pediatric radiological procedures bring concern due to the high life expectancy and radiosensitivity on children, as well as the risks to the exposed staff Important studies present the mean KAP values on patients and the European Commission (EC) recommends specific techniques for these procedures. For the occupational expositions, staffs doses must be within the annual limit, according to the CNEN 3.01. Based on those data, the aims of the current study are: analyzing the upper GI procedure; determining the KAP on the patient and estimating the annual equivalent dose on the staff's crystalline. LiF :Mg,Ti TLDs were positioned on the patient upper chest center, so that the entrance surface air kerma could be determined. The field size on the patient s surface and the kerma were multiplied so that the KAP was obtained. LiF:Mg,Cu,P dosimeters were used to estimate the equivalent dose on the staff s crystalline. The results showed discrepancy in the kVp range and in the exposure time when compared to the EC data. The mean KAP values for the 0-1,1-3 and 3-10 years old patients were, respectively: 102 ± 19 cGy.cm2, 142 ± 25 cGy.cm2 and 323 ± 39 cGy.cm2; which are higher than the KAPs presented in the studies used for comparison. The estimated annual equivalent dose in the staff s crystalline would be approximately 85% higher than the limit set by the CNEN. Analyzing the data, it becomes clear that an optimization implementation is necessary in order to reduce the radiation levels. (author)

  20. Pediatric and staff dose evaluation in fluoroscopy upper gastrointestinal series

    International Nuclear Information System (INIS)

    Filipov, Danielle; Nascimento, Eduarda X. do; Lacerda, Camila M.; Schelin, Hugo R.; Ledesma, Jorge A.; Denyak, Valeriy; Legnani, Adriano

    2014-01-01

    Fluoroscopy upper GI series are widely used for the diagnosis of gastroesophageal reflux disease in children. Pediatric radiological procedures bring concern due to the high life expectancy and radiosensitivity on children, as well as the risks to the exposed staff Important studies present the mean KAP values on patients and the European Commission (EC) recommends specific techniques for these procedures. For the occupational expositions, staffs doses must be within the annual limit, according to the CNEN 3.01. Based on those data, the aims of the current study are: analyzing the upper GI procedure; determining the KAP on the patient and estimating the annual equivalent dose on the staff's crystalline. LiF :Mg,Ti TLDs were positioned on the patient upper chest center, so that the entrance surface air kerma could be determined. The field size on the patient s surface and the kerma were multiplied so that the KAP was obtained. LiF:Mg,Cu,P dosimeters were used to estimate the equivalent dose on the staff s crystalline. The results showed discrepancy in the kVp range and in the exposure time when compared to the EC data. The mean KAP values for the 0-1,1-3 and 3-10 years old patients were, respectively: 102 ± 19 cGy.cm2, 142 ± 25 cGy.cm2 and 323 ± 39 cGy.cm2; which are higher than the KAPs presented in the studies used for comparison. The estimated annual equivalent dose in the staff s crystalline would be approximately 85% higher than the limit set by the CNEN. Analyzing the data, it becomes clear that an optimization implementation is necessary in order to reduce the radiation levels. (author)

  1. Experimentally studied dynamic dose interplay does not meaningfully affect target dose in VMAT SBRT lung treatments

    Energy Technology Data Exchange (ETDEWEB)

    Stambaugh, Cassandra [Department of Physics, University of South Florida, Tampa, Florida 33612 (United States); Nelms, Benjamin E. [Canis Lupus LLC, Merrimac, Wisconsin 53561 (United States); Dilling, Thomas; Stevens, Craig; Latifi, Kujtim; Zhang, Geoffrey; Moros, Eduardo; Feygelman, Vladimir [Department of Radiation Oncology, Moffitt Cancer Center, Tampa, Florida 33612 (United States)

    2013-09-15

    Purpose: The effects of respiratory motion on the tumor dose can be divided into the gradient and interplay effects. While the interplay effect is likely to average out over a large number of fractions, it may play a role in hypofractionated [stereotactic body radiation therapy (SBRT)] treatments. This subject has been extensively studied for intensity modulated radiation therapy but less so for volumetric modulated arc therapy (VMAT), particularly in application to hypofractionated regimens. Also, no experimental study has provided full four-dimensional (4D) dose reconstruction in this scenario. The authors demonstrate how a recently described motion perturbation method, with full 4D dose reconstruction, is applied to describe the gradient and interplay effects during VMAT lung SBRT treatments.Methods: VMAT dose delivered to a moving target in a patient can be reconstructed by applying perturbations to the treatment planning system-calculated static 3D dose. Ten SBRT patients treated with 6 MV VMAT beams in five fractions were selected. The target motion (motion kernel) was approximated by 3D rigid body translation, with the tumor centroids defined on the ten phases of the 4DCT. The motion was assumed to be periodic, with the period T being an average from the empirical 4DCT respiratory trace. The real observed tumor motion (total displacement ≤8 mm) was evaluated first. Then, the motion range was artificially increased to 2 or 3 cm. Finally, T was increased to 60 s. While not realistic, making T comparable to the delivery time elucidates if the interplay effect can be observed. For a single fraction, the authors quantified the interplay effect as the maximum difference in the target dosimetric indices, most importantly the near-minimum dose (D{sub 99%}), between all possible starting phases. For the three- and five-fractions, statistical simulations were performed when substantial interplay was found.Results: For the motion amplitudes and periods obtained from

  2. Georgia fishery study: implications for dose calculations

    International Nuclear Information System (INIS)

    Turcotte, M.D.S.

    1983-01-01

    Fish consumption will contribute a major portion of the estimated individual and population doses from L-Reactor liquid releases and Cs-137 remobilization in Steel Creek. It is therefore important that the values for fish consumption used in dose calculations be as realistic as possible. Since publication of the L-Reactor Environmental Information Document (EID), data have become available on sport fishing in the Savannah River. These data provide SRP with site-specific sport fish harvest and consumption values for use in dose calculations. The Georgia fishery data support the total population fish consumption and calculated dose reported in the EID. The data indicate, however, that both the EID average and maximum individual fish consumption have been underestimated, although each to a different degree. The average fish consumption value used in the EID is approximately 3% below the lower limit of the fish consumption range calculated using the Georgia data. A fish consumption value of 11.3 kg/yr should be used to recalculate dose to the average individual from L-Reactor restart. Maximum fish consumption in the EID has been underestimated by approximately 60%, and doses to the maximum individual should also be recalculated. Future dose calculations should utilize an average fish consumption value of 11.3 kg/yr, and a maximum fish consumption value of 34 kg/yr

  3. Controlled single-blind clinical evaluation of low-dose mammographic screen: film systems

    International Nuclear Information System (INIS)

    Sickles, E.A.; Genant, H.K.

    1979-01-01

    The ability of five low-dose mammographic screen-film systems to portray normal and abnormal breast structures was evaluated in parallel with a study of physical image properties. Single-blind evaluations of the visibility of normal breast architecture, mass lesions, and calcifications were made on the mammograms of 100 patients radiographed with each of the systems. There was increased noise and slightly poorer resolution of the faster recording systems, but there was no difference in final diagnostic impressions among the five systems. These results suggest that the faster systems will result in substantial dose reduction without sacrificing diagnostic accuracy

  4. Evaluation of radiation dose to pediatric patients during certain special procedures

    International Nuclear Information System (INIS)

    Sulieman, A.; Alzimami, K.; Elhag, B.; Babikir, E.; Alsafi, K.

    2014-01-01

    This study was intended to measure pediatric entrance surface air kerma (ESAK) and effective dose during micturating cystourethrography (MCU), intravenous urography (IVU) and barium studies (barium meal, enema, and swallow) and to propose a local diagnostic reference level (DRL). ESAK was measured for patients using calibrated thermoluminescent dosimeters (TLDs, GR200A). Effective doses (E) were calculated using the National Radiological Protection Board (NRPB) software. A total of 236 special pediatric procedures were investigated. 21.7% of the sample comprised barium procedures, 18.6% were MCU procedures while 59.5% of the sample were IVU procedures. The mean ESAK measurements (mGy) were 2.1±0.8, 3.0±23 and 1.2±0.2 for barium meal, enema and swallow in the same order. The mean patient dose for IVU procedures was 12.4±8.7 mGy per procedure and the mean patient dose per MCU procedure was 5.8±7 mGy. Local DRLs were proposed for all procedures. The patient doses in this study are within the reported values, suggesting that pediatric patients are adequately protected. - Highlights: • Pediatric radiation dose has been evaluated for three of the most common fluoroscopic procedures. • Radiation doses were measured using calibrated TLD GR200A. • Pediatric patients of concern and ESAK doses showed large variations. • The patient doses in this study are within the reported studies suggesting that the pediatric patients are adequately protected

  5. Evaluation of the absorbed dose in odontological computerized tomography; Avaliacao da dose absorvida em tomografia computadorizada odontologica

    Energy Technology Data Exchange (ETDEWEB)

    Legnani, Adriano; Schelin, Hugo R.; Rocha, Anna Silvia P.S. da, E-mail: schelin@utfpr.edu.b, E-mail: anna@utfpr.edu.b [Universidade Tecnologica Federal do Parana (UTFPR), Curitiba, PR (Brazil); Khoury, Helen J., E-mail: khoury@ufpe.b [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil)

    2011-10-26

    This paper evaluated the absorbed dose at the surface entry known as 'cone beam computed tomography' (CBCT) in odontological computerized tomography. Examination were simulated with CBCT for measurements of dose. A phantom were filled with water, becoming scatter object of radiation. Thermoluminescent dosemeters were positioned on points correspondent to eyes and salivary glands

  6. Evaluation of the absorbed dose in odontological computerized tomography; Avaliacao da dose absorvida em tomografia computadorizada odontologica

    Energy Technology Data Exchange (ETDEWEB)

    Legnani, Adriano; Schelin, Hugo R; Rocha, Anna Silvia P.S. da, E-mail: schelin@utfpr.edu.b, E-mail: anna@utfpr.edu.b [Universidade Tecnologica Federal do Parana (UTFPR), Curitiba, PR (Brazil); Khoury, Helen J., E-mail: khoury@ufpe.b [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil)

    2011-10-26

    This paper evaluated the absorbed dose at the surface entry known as 'cone beam computed tomography' (CBCT) in odontological computerized tomography. Examination were simulated with CBCT for measurements of dose. A phantom were filled with water, becoming scatter object of radiation. Thermoluminescent dosemeters were positioned on points correspondent to eyes and salivary glands

  7. Performance evaluation of domestic prototype dose area product meter SFT-1

    International Nuclear Information System (INIS)

    Lee, Ho Sun; Han, Seong Gyu; Roh, Young Roh; Lim, Hyun Jong; Kim, Jung Min; Kim, Jong Uk; Chae, Hyun Sik; Yoon, Yong Su

    2016-01-01

    The importance of radiation dose display of medical X-ray equipment was emphasized, while third edition of IEC(International Electrotechnical Commission) 60601 started to apply. The existing medical X-ray equipment selected a method for attaching the DAP(Dose Area Product) meter when the dose display. However, because the DAP meter was dependent on all of the income, And it did not yet produced in Korea. So, we received the support of Seoul R and BD Program(Grants No. C1152055) to produce DAP meter prototype of the Domestically technology. In this study, the performance of this prototype was evaluated by comparing the German company's product. Evaluation item was an electronic capture performance, radiation dose dependence, radiation quality dependence, energy transmittance, repeatability, light transmittance of 6 entries. And IEC 60580 was based on this evaluation. Evaluation results were electronic capture performance intrinsic error 9.5%, radiation dose dependence limits of variation 1%, repeatabilit y coefficient of variation 2%, energy transmittance 91% each assessment was passed. However radiation quality dependence limits of variation 29%, light transmittance 55% was less than acceptance criteria

  8. Relief and Recurrence of Congestion During and After Hospitalization for Acute Heart Failure: Insights From Diuretic Optimization Strategy Evaluation in Acute Decompensated Heart Failure (DOSE-AHF) and Cardiorenal Rescue Study in Acute Decompensated Heart Failure (CARESS-HF).

    Science.gov (United States)

    Lala, Anuradha; McNulty, Steven E; Mentz, Robert J; Dunlay, Shannon M; Vader, Justin M; AbouEzzeddine, Omar F; DeVore, Adam D; Khazanie, Prateeti; Redfield, Margaret M; Goldsmith, Steven R; Bart, Bradley A; Anstrom, Kevin J; Felker, G Michael; Hernandez, Adrian F; Stevenson, Lynne W

    2015-07-01

    Congestion is the most frequent cause for hospitalization in acute decompensated heart failure. Although decongestion is a major goal of acute therapy, it is unclear how the clinical components of congestion (eg, peripheral edema, orthopnea) contribute to outcomes after discharge or how well decongestion is maintained. A post hoc analysis was performed of 496 patients enrolled in the Diuretic Optimization Strategy Evaluation in Acute Decompensated Heart Failure (DOSE-AHF) and Cardiorenal Rescue Study in Acute Decompensated Heart Failure (CARRESS-HF) trials during hospitalization with acute decompensated heart failure and clinical congestion. A simple orthodema congestion score was generated based on symptoms of orthopnea (≥2 pillows=2 points, fails to relieve orthodema during hospitalization or to prevent recurrence after discharge. URL: http://www.clinicaltrials.gov. Unique identifiers: NCT00608491, NCT00577135. © 2015 American Heart Association, Inc.

  9. Does iterative reconstruction lower CT radiation dose: evaluation of 15,000 examinations.

    Directory of Open Access Journals (Sweden)

    Peter B Noël

    Full Text Available PURPOSE: Evaluation of 15,000 computed tomography (CT examinations to investigate if iterative reconstruction (IR reduces sustainably radiation exposure. METHOD AND MATERIALS: Information from 15,000 CT examinations was collected, including all aspects of the exams such as scan parameter, patient information, and reconstruction instructions. The examinations were acquired between January 2010 and December 2012, while after 15 months a first generation IR algorithm was installed. To collect the necessary information from PACS, RIS, MPPS and structured reports a Dose Monitoring System was developed. To harvest all possible information an optical character recognition system was integrated, for example to collect information from the screenshot CT-dose report. The tool transfers all data to a database for further processing such as the calculation of effective dose and organ doses. To evaluate if IR provides a sustainable dose reduction, the effective dose values were statistically analyzed with respect to protocol type, diagnostic indication, and patient population. RESULTS: IR has the potential to reduce radiation dose significantly. Before clinical introduction of IR the average effective dose was 10.1±7.8mSv and with IR 8.9±7.1mSv (p*=0.01. Especially in CTA, with the possibility to use kV reduction protocols, such as in aortic CTAs (before IR: average14.2±7.8mSv; median11.4mSv /with IR:average9.9±7.4mSv; median7.4mSv, or pulmonary CTAs (before IR: average9.7±6.2mSV; median7.7mSv /with IR: average6.4±4.7mSv; median4.8mSv the dose reduction effect is significant(p*=0.01. On the contrary for unenhanced low-dose scans of the cranial (for example sinuses the reduction is not significant (before IR:average6.6±5.8mSv; median3.9mSv/with IR:average6.0±3.1mSV; median3.2mSv. CONCLUSION: The dose aspect remains a priority in CT research. Iterative reconstruction algorithms reduce sustainably and significantly radiation dose in the clinical routine

  10. Patient dose in image guided radiotherapy: Monte Carlo study of the CBCT dose contribution

    OpenAIRE

    Leotta, Salvatore; Amato, Ernesto; Settineri, Nicola; Basile, Emilia; Italiano, Antonio; Auditore, Lucrezia; Santacaterina, Anna; Pergolizzi, Stefano

    2018-01-01

    Image Guided RadioTherapy (IGRT) is a technique whose diffusion is growing thanks to the well-recognized gain in accuracy of dose delivery. However, multiple Cone Beam Computed Tomography (CBCT) scans add dose to patients, and its contribution has to be assessed and minimized. Aim of our work was to evaluate, through Monte Carlo simulations, organ doses in IGRT due to CBCT and therapeutic MV irradiation in head-neck, thorax and pelvis districts. We developed a Monte Carlo simulation in GAMOS ...

  11. 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

  12. A randomized, single-blind, single-dose study evaluating the pharmacokinetic equivalence of proposed biosimilar ABP 980 and trastuzumab in healthy male subjects.

    Science.gov (United States)

    Hanes, Vladimir; Chow, Vincent; Zhang, Nan; Markus, Richard

    2017-05-01

    This study compared the pharmacokinetic (PK) profiles of the proposed biosimilar ABP 980 and trastuzumab in healthy males. In this single-blind study, 157 healthy males were randomized 1:1:1 to a single 6 mg/kg intravenous infusion of ABP 980, FDA-licensed trastuzumab [trastuzumab (US)], or EU-authorized trastuzumab [trastuzumab (EU)]. Primary endpoints were area under the serum concentration-time curve from time 0 to infinity (AUC inf ) and maximum observed serum concentration (C max ). To establish equivalence, the geometric mean ratio (GMR) and 90% confidence interval (CI) for C max and AUC inf had to be within the equivalence criteria of 0.80-1.25. The GMRs and 90% CIs for C max and AUC inf , respectively, were: 1.04 (0.99-1.08) and 1.06 (1.00-1.12) for ABP 980 versus trastuzumab (US); 0.99 (0.95-1.03) and 1.00 (0.95-1.06) for ABP 980 versus trastuzumab (EU); and 0.96 (0.92-1.00) and 0.95 (0.90-1.01) for trastuzumab (US) versus trastuzumab (EU). All comparisons were within the equivalence criteria of 0.80-1.25. Treatment-emergent adverse events (TEAEs) were reported in 84.0, 75.0, and 78.2 of subjects in the ABP 980, trastuzumab (US), and trastuzumab (EU) groups, respectively. There were no deaths or TEAEs leading to study discontinuation and no binding or neutralizing anti-drug anti-bodies were detected. This study demonstrated the PK similarity of ABP 980 to both trastuzumab (US) and trastuzumab (EU), and of trastuzumab (US) to trastuzumab (EU). No differences in safety and tolerability between treatments were noted; no subject tested positive for binding anti-bodies.

  13. [Evaluation of an Experimental Production Wireless Dose Monitoring System for Radiation Exposure Management of Medical Staff].

    Science.gov (United States)

    Fujibuchi, Toshioh; Murazaki, Hiroo; Kuramoto, Taku; Umedzu, Yoshiyuki; Ishigaki, Yung

    2015-08-01

    Because of the more advanced and more complex procedures in interventional radiology, longer treatment times have become necessary. Therefore, it is important to determine the exposure doses received by operators and patients. The aim of our study was to evaluate an experimental production wireless dose monitoring system for pulse radiation in diagnostic X-ray. The energy, dose rate, and pulse fluoroscopy dependence were evaluated as the basic characteristics of this system for diagnostic X-ray using a fully digital fluoroscopy system. The error of 1 cm dose equivalent rate was less than 15% from 35.1 keV to 43.2 keV with energy correction using metal filter. It was possible to accurately measure the dose rate dependence of this system, which was highly linear until 100 μSv/h. This system showed a constant response to the pulse fluoroscopy. This system will become useful wireless dosimeter for the individual exposure management by improving the high dose rate and the energy characteristics.

  14. Radiation dose evaluation of dental cone beam computed tomography using an anthropomorphic adult head phantom

    Science.gov (United States)

    Wu, Jay; Shih, Cheng-Ting; Ho, Chang-hung; Liu, Yan-Lin; Chang, Yuan-Jen; Min Chao, Max; Hsu, Jui-Ting

    2014-11-01

    Dental cone beam computed tomography (CBCT) provides high-resolution tomographic images and has been gradually used in clinical practice. Thus, it is important to examine the amount of radiation dose resulting from dental CBCT examinations. In this study, we developed an in-house anthropomorphic adult head phantom to evaluate the level of effective dose. The anthropomorphic phantom was made of acrylic and filled with plaster to replace the bony tissue. The contour of the head was extracted from a set of adult computed tomography (CT) images. Different combinations of the scanning parameters of CBCT were applied. Thermoluminescent dosimeters (TLDs) were used to measure the absorbed doses at 19 locations in the head and neck regions. The effective doses measured using the proposed phantom at 65, 75, and 85 kVp in the D-mode were 72.23, 100.31, and 134.29 μSv, respectively. In the I-mode, the effective doses were 108.24, 190.99, and 246.48 μSv, respectively. The maximum percent error between the doses measured by the proposed phantom and the Rando phantom was l4.90%. Therefore, the proposed anthropomorphic adult head phantom is applicable for assessing the radiation dose resulting from clinical dental CBCT.

  15. Evaluation of radiological doses to the terrestrial plants around Trombay

    International Nuclear Information System (INIS)

    Ajay Kumar; Singhal, R.K.; Preetha, J.; Joshi, S.N.; Hegde, A.G.

    2005-01-01

    Existing policies for radiation protection do not provide explicit criteria for the protection of species other than humans, i.e. not for flora and fauna. Concern over this omission is now being widely expressed and moves are under way to evaluate the doses to terrestrial and aquatic biota. During the present work radiological doses (external and internal) to the terrestrial plants were evaluated by estimating the concentration of anthropogenic ( 137 Cs, 90 Sr) and natural radionuclides ( 238 U, 232 Th and 40 K) in the plant leaves and by measuring the external gamma radiation due to different radionuclide. The soil and vegetation sample were collected from fifteen sampling locations around the different locations at Trombay. The samples were processed as per IAEA (International Atomic Energy Agency) protocol for the estimation of naturally occurring and anthropogenic radionuclides in soil and terrestrial plants. The gamma emitting radionuclides were measured by high resolution gamma (HPGe) spectrometry system. Maximum exposure (external + internal) to the terrestrial plants was observed due to 232 Th while 238 U showed minimum exposure. The average value of radiation exposure to the terrestrial plants for 40 K, 137 Cs, 90 Sr, 238 U and 232 Th was 1555.2 ± 92.4, 691.2 ± 54.3, 2564.1 ± 534.9, 82.5 ±5.2, and 4419.6 ± 1165.5 μGy/y respectively. The radiation exposure (external + internal ) to the terrestrial plants due to all radionuclides was found within the permissible limits (i.e. 10 mGy/d) as per recommended by the United States, Department of Energy (DOE). (author)

  16. Dose and risk evaluation to the thyroid gland in intra-oral dental radiology

    International Nuclear Information System (INIS)

    Souza, Edmilson M.; Lima, Marco A.F.; Kelecom, Alphonse; Correa, Samanda C.A.; Silva, Ademir X.; Brito, Alan

    2008-01-01

    Intra-oral technique is one of the most frequently used procedures of dental radiology, allowing the detection of a variety of dental anomalies such as caries, dental trauma and periodontal lesions, while exposing patients to relatively low doses of radiation. However, although the adverse effects of doses generated by dental radiology are essentially stochastic, a number of epidemiological studies have provided evidence of an increased risk of thyroid tumors for dental radiography. Many studies have measured doses of radiation for dental radiography, but only a few have estimated thyroid dose. Furthermore, most of the studies on dose evaluation in dental radiology are based on standardized calculation phantoms, which neglect the variance of the patient size or even sex. The purpose of this study is to use the Monte Carlo code MCNPX and the FAX (Female Adult voXel) and MAX (Male Adult voXel) phantoms to investigate how absorbed doses to the thyroid gland in intraoral dental examinations vary in female and male patients. The lifetime cancer incidence attributable to dental examinations were estimated using the Biological Effects of Ionizing Radiations (BEIR) VII Committee Report. The phantoms study proved a useful trial for detecting the radiation dose to the thyroid gland and conclusively supported that the anatomy may be regarded as an influencing factor in radiation dose received during dental examination. Finally, the results have also confirmed that the association of the MCNPX code and the MAX and FAX phantoms is very useful in dosimetric studies on radiographic examinations of female and male patients. (author)

  17. A spatially encoded dose difference maximal intensity projection map for patient dose evaluation: A new first line patient quality assurance tool

    Energy Technology Data Exchange (ETDEWEB)

    Hu Weigang; Graff, Pierre; Boettger, Thomas; Pouliot, Jean [Department of Radiation Oncology, University of California, San Francisco, San Francisco, California 94143 (United States); and others

    2011-04-15

    Purpose: To develop a spatially encoded dose difference maximal intensity projection (DD-MIP) as an online patient dose evaluation tool for visualizing the dose differences between the planning dose and dose on the treatment day. Methods: Megavoltage cone-beam CT (MVCBCT) images acquired on the treatment day are used for generating the dose difference index. Each index is represented by different colors for underdose, acceptable, and overdose regions. A maximal intensity projection (MIP) algorithm is developed to compress all the information of an arbitrary 3D dose difference index into a 2D DD-MIP image. In such an algorithm, a distance transformation is generated based on the planning CT. Then, two new volumes representing the overdose and underdose regions of the dose difference index are encoded with the distance transformation map. The distance-encoded indices of each volume are normalized using the skin distance obtained on the planning CT. After that, two MIPs are generated based on the underdose and overdose volumes with green-to-blue and green-to-red lookup tables, respectively. Finally, the two MIPs are merged with an appropriate transparency level and rendered in planning CT images. Results: The spatially encoded DD-MIP was implemented in a dose-guided radiotherapy prototype and tested on 33 MVCBCT images from six patients. The user can easily establish the threshold for the overdose and underdose. A 3% difference between the treatment and planning dose was used as the threshold in the study; hence, the DD-MIP shows red or blue color for the dose difference >3% or {<=}3%, respectively. With such a method, the overdose and underdose regions can be visualized and distinguished without being overshadowed by superficial dose differences. Conclusions: A DD-MIP algorithm was developed that compresses information from 3D into a single or two orthogonal projections while hinting the user whether the dose difference is on the skin surface or deeper.

  18. A spatially encoded dose difference maximal intensity projection map for patient dose evaluation: a new first line patient quality assurance tool.

    Science.gov (United States)

    Hu, Weigang; Graff, Pierre; Boettger, Thomas; Pouliot, Jean

    2011-04-01

    To develop a spatially encoded dose difference maximal intensity projection (DD-MIP) as an online patient dose evaluation tool for visualizing the dose differences between the planning dose and dose on the treatment day. Megavoltage cone-beam CT (MVCBCT) images acquired on the treatment day are used for generating the dose difference index. Each index is represented by different colors for underdose, acceptable, and overdose regions. A maximal intensity projection (MIP) algorithm is developed to compress all the information of an arbitrary 3D dose difference index into a 2D DD-MIP image. In such an algorithm, a distance transformation is generated based on the planning CT. Then, two new volumes representing the overdose and underdose regions of the dose difference index are encoded with the distance transformation map. The distance-encoded indices of each volume are normalized using the skin distance obtained on the planning CT. After that, two MIPs are generated based on the underdose and overdose volumes with green-to-blue and green-to-red lookup tables, respectively. Finally, the two MIPs are merged with an appropriate transparency level and rendered in planning CT images. The spatially encoded DD-MIP was implemented in a dose-guided radiotherapy prototype and tested on 33 MVCBCT images from six patients. The user can easily establish the threshold for the overdose and underdose. A 3% difference between the treatment and planning dose was used as the threshold in the study; hence, the DD-MIP shows red or blue color for the dose difference > 3% or < or = 3%, respectively. With such a method, the overdose and underdose regions can be visualized and distinguished without being overshadowed by superficial dose differences. A DD-MIP algorithm was developed that compresses information from 3D into a single or two orthogonal projections while hinting the user whether the dose difference is on the skin surface or deeper.

  19. A feasibility study evaluating the relationship between dose and focal liver reaction in stereotactic ablative radiotherapy for liver cancer based on intensity change of Gd-EOB-DTPA-enhanced magnetic resonance images

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Sang Hoon; Yu, Jeong Il; Park, Hee Chul; Lim, Do Hoon; Han, Young Yih [Dept. of Radiation Oncology, amsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)

    2016-03-15

    In order to evaluate the relationship between the dose to the liver parenchyma and focal liver reaction (FLR) after stereotactic ablative body radiotherapy (SABR), we suggest a novel method using a three-dimensional dose distribution and change in signal intensity of gadoxetate disodium-gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI) hepatobiliary phase images. In our method, change of the signal intensity between the pretreatment and follow-up hepatobiliary phase images of Gd-EOB-DTPA-enhanced MRI was calculated and then threshold dose (TD) for developing FLR was obtained from correlation of dose with the change of the signal intensity. For validation of the method, TDs for six patients, who had been treated for liver cancer with SABR with 45-60 Gy in 3 fractions, were calculated using the method, and we evaluated concordance between volume enclosed by isodose of TD by the method and volume identified as FLR by a physician. The dose to normal liver was correlated with change in signal intensity between pretreatment and follow-up MRI with a median R{sup 2} of 0.935 (range, 0.748 to 0.985). The median TD by the method was 23.5 Gy (range, 18.3 to 39.4 Gy). The median value of concordance was 84.5% (range, 44.7% to 95.9%). Our method is capable of providing a quantitative evaluation of the relationship between dose and intensity changes on follow-up MRI, as well as determining individual TD for developing FLR. We expect our method to provide better information about the individual relationship between dose and FLR in radiotherapy for liver cancer.

  20. A feasibility study evaluating the relationship between dose and focal liver reaction in stereotactic ablative radiotherapy for liver cancer based on intensity change of Gd-EOB-DTPA-enhanced magnetic resonance images

    International Nuclear Information System (INIS)

    Jung, Sang Hoon; Yu, Jeong Il; Park, Hee Chul; Lim, Do Hoon; Han, Young Yih

    2016-01-01

    In order to evaluate the relationship between the dose to the liver parenchyma and focal liver reaction (FLR) after stereotactic ablative body radiotherapy (SABR), we suggest a novel method using a three-dimensional dose distribution and change in signal intensity of gadoxetate disodium-gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI) hepatobiliary phase images. In our method, change of the signal intensity between the pretreatment and follow-up hepatobiliary phase images of Gd-EOB-DTPA-enhanced MRI was calculated and then threshold dose (TD) for developing FLR was obtained from correlation of dose with the change of the signal intensity. For validation of the method, TDs for six patients, who had been treated for liver cancer with SABR with 45-60 Gy in 3 fractions, were calculated using the method, and we evaluated concordance between volume enclosed by isodose of TD by the method and volume identified as FLR by a physician. The dose to normal liver was correlated with change in signal intensity between pretreatment and follow-up MRI with a median R 2 of 0.935 (range, 0.748 to 0.985). The median TD by the method was 23.5 Gy (range, 18.3 to 39.4 Gy). The median value of concordance was 84.5% (range, 44.7% to 95.9%). Our method is capable of providing a quantitative evaluation of the relationship between dose and intensity changes on follow-up MRI, as well as determining individual TD for developing FLR. We expect our method to provide better information about the individual relationship between dose and FLR in radiotherapy for liver cancer

  1. Early termination of prostate cancer hyperfractionated dose escalation study

    International Nuclear Information System (INIS)

    Forman, Jeffrey D; Porter, Arthur T; Kocheril, Paul; Grignon, David; Orton, Colin

    1996-01-01

    Purpose: This study was initiated to determine the maximum tolerable dose of hyperfractionated radiation in patients with locally advanced prostate cancer. Materials and Methods: Forty-nine patients with locally advanced prostate cancer (T3-T4 Nx, 0, 1 M0 and/or Gleason Score ≥ 8) were treated on the first two steps of a prospective dose-escalation study using hyperfractionated conformal radiotherapy. The first 25 patients received a minimum dose of 78Gy to the clinical tumor volume (CTV) including the prostate, seminal vesicle and a 5mm margin at 1.3Gy b.i.d. The second group (24 patients) received a minimum dose to the CTV of 82.8Gy at 1.15Gy b.i.d. Twenty eight patients received neo-adjuvant hormonal therapy in conjunction with their radiation (8 of 25 patients at 78Gy and 20 of 24 patients at 82.8Gy). Toxicity was scored according to the RTOG grading scale. Efficacy was evaluated by PSA levels and ultrasound guided biopsies. Median follow up was 36 and 18 months for the 78Gy and 82.8Gy dose levels, respectively. Results: No grade 3 or 4 gastrointestinal (GI) or genitourinary (GU) toxicity was noted. At 36 months, the actuarial probability of Grade 2 GI and GU toxicity were 16 and 20%, respectively. Twelve to 18 months following radiation, 41 patients (86%) underwent ultrasound guided biopsy. At 78Gy, 60% of 20 patients had a biopsy which was negative or showed a marked therapeutic effect. At 82.8Gy, these combined rates were 95% in the 21 patients who had biopsies. Nine patients (50%) who did not receive neo-adjuvant hormones had positive biopsies. No patient who received neo-adjuvant hormones plus 78Gy (5 patients) or 82.8Gy (18 patients) had a positive biopsy. Conclusion: Proceeding to the next dose level (87.4Gy) was justified by the lack of severe chronic toxicity. However, in view of the high rate of histologic sterilization when hyperfractionated irradiation was given in conjunction with neo-adjuvant hormonal therapy, it was felt to be unethical to

  2. The evaluation the magnitude radiation exposure dose rate in digital radiography room design

    Science.gov (United States)

    Dwiyanto, Agung; Setia Budi, Wahyu; Hardiman, Gagoek

    2017-12-01

    This study discusses the dose rate in digital radiography room, buit according to meet the provisions of KEMENKES No.1014 / Menkes / SK / XI / 2008 and Regulation of BAPETEN No. 8 / 2011. The provisions primary concern of radiation safety, not comfort, by considering the space design. There are five aspects to consider in designing the space: functionality, comfort, security, movement activities and aesthetics. However provisions only met three aspects of the design, which are a function, security and movement activity. Therefore, it is necessary to evaluate digital radiography room in terms of its ability to control external radiation exposure to be safe and comfortable The dose rate is measured by the range of primary and secondary radiation in the observation points by using Surveymeter. All data are obtained by the preliminary survey prior to the study. Furthermore, the review of digital radiography room is done based on architectural design theory. The dose rate for recommended improvement room is recalculated using the same method as the actual room with the help of computer modeling. The result of dose rate calculation at the inner and outer part of digital radiography observation room shows that in-room dose for a week at each measuring point exceeds the allowable dose limit both for staff and public. During a week of observation, the outdoor dose at some measuring points exceeds the dose limit set by the KEMENKES No.1014 / Menkes / SK / XI / 2008 and Regulation BEPETEN No 8/2011. Meanwhile, the result of dose rate calculation in the inner and outer part of the improved digital radiography room can meet the applicable regulations better.

  3. Study of dose calculation and beam parameters optimization with genetic algorithm in IMRT

    International Nuclear Information System (INIS)

    Chen Chaomin; Tang Mutao; Zhou Linghong; Lv Qingwen; Wang Zhuoyu; Chen Guangjie

    2006-01-01

    Objective: To study the construction of dose calculation model and the method of automatic beam parameters selection in IMRT. Methods: The three-dimension convolution dose calculation model of photon was constructed with the methods of Fast Fourier Transform. The objective function based on dose constrain was used to evaluate the fitness of individuals. The beam weights were optimized with genetic algorithm. Results: After 100 iterative analyses, the treatment planning system produced highly conformal and homogeneous dose distributions. Conclusion: the throe-dimension convolution dose calculation model of photon gave more accurate results than the conventional models; genetic algorithm is valid and efficient in IMRT beam parameters optimization. (authors)

  4. Radiation dose of staff during positron emission tomography study

    Energy Technology Data Exchange (ETDEWEB)

    Hachiya, Takenori; Shoji, Yasuaki; Hagami, Eiichi; Aizawa, Yasuo; Onodera, Hiroshi; Kan, Mikio; Sasaki, Nobuo; Toyoshima, Eiji; Sugawara, Shigeki

    1989-04-01

    In this paper, the radiation dose of the PET staff including blood sampling operators (medical doctors), PET operators (radio technologists), nurses, blood analysts (medical technologists), radiochemists and cyclotron operators in the cyclotron-PET unit was evaluated. The dose was measured using the film-badges for whole body and TLD ring-badges for fingers. These data were obtained from June, 1986 to May, 1987. In the average dose per month, those with the highest dose were radiochemists. The whole body dose was 1.08 mSv (108 mrem) for /gamma/-ray, 520 /mu/Sv (52 mrem) for /beta/-ray and the dose for fingers, 7.6mSv (760 mrem). The total dose per year both for /gamma/ and /beta/-ray was 19.2 mSv (1.92 rem) for whole body and 91.2 mSv (9.12 rem) for fingers. The staff with the lowest whole body dose for /gamma/-ray per month was blood analysts whose dose was 30 /mu/Sv (3 mrem). For the staff consisting of doctors, radiotechnologists and nurses, the whole body dose per month was 70-170/mu/Sv (7-17 mrem) for /gamma/-ray, 20 /mu/Sv (2 mrem) for /beta/-ray and the dose for fingers per month was 210-540 /mu/Sv (21-54 mrem). For cyclotron operators, the dose was 90 /mu/Sv (9 mrem) for /gamma/-ray, 30 /mu/Sv (3 mrem) for /beta/-ray and the dose for fingers was 160 /mu/Sv (16 mrem). For cyclotron operators and radiochemists, the whole body dose for the neutron ray was measured by solid state nuclear track detector (SSNTD), but the dose was found to be negligible. (author).

  5. Overview of internal dose evaluation in the radiopharmaceutical production plant at IPEN

    International Nuclear Information System (INIS)

    Todo, Alberto S.; Gerulis, Eduardo; Cardoso, Joaquim C.S.; Rodrigues Junior, Orlando

    2015-01-01

    The internal dosimetry program at the Instituto de Pesquisas Energeticas e Nucleares, IPEN, is accomplished in two steps: the activity measurements are performed at the In Vivo Monitoring Laboratory and subsequently the data analysis and the dose evaluation are carried out by the Dose Calculation Group according to the ICRP models. The objective of this study is to take the whole body and thyroid monitoring results recorded from 2005 to 2015 to see whether the internal contamination control procedure for workers were suitable even with the increase in the radiopharmaceutical production. The study were based in a research called “Search of Variables” for the operations carried out in the restricted areas of radiopharmaceutical production plant, taking into account the dose distribution data for all the tasks recorded by the radioprotection service. This methodology aims to identify and determine the principal variables that impact on the worker's dose. The results were presented for the following variables: individual occupationally exposed, operation variable, area/cell, type of task of operation, which depend on the variable dose. In spite of growth rate in the production of radiopharmaceutical, this study has shown that the improvements in the plant have contributed to the dose reduction of the workers. (author)

  6. Topics on study of low dose-effect relationship

    International Nuclear Information System (INIS)

    Yamada, Takeshi; Ohyama, Harumi

    1999-01-01

    It is not exceptional but usually observed that a dose-effect relationship in biosystem is not linear. Sometimes, the low dose-effect relationship appears entirely contrary to the expectation from high dose-effect. This is called a 'hormesis' phenomena. A high dose irradiation inflicts certainly an injury on biosystem. No matter how low the dose may be, an irradiation might inflict some injury on biosystem according to Linear Non-Threshold hypothesis(LNT). On the contrary to the expectation, a low dose irradiation stimulates immune system, and promotes cell proliferation. This is called 'radiation hormesis'. The studies of the radiation hormesis are made on from four points of view as follows: (1) radiation adaptive response, (2) revitalization caused by a low dose stimulation, (3) a low dose response unexpected from the LNT hypothesis, (4) negation of the LNT hypothesis. The various empirical proofs of radiation hormesis are introduced in the report. (M . Suetake)

  7. An epidemiological study for the reduction of population radiation dose

    International Nuclear Information System (INIS)

    Gamo, Makoto

    1989-01-01

    The correlation of tube voltage with patient exposure was studied using effective dose as an indicator of dose reduction in intraoral radiography. The results were as follows: l. The salivary gland tissues contributed the most to the effective dose of intraoral radiography. 2. In the 50 to 90 kV range, there was no appreciable correlation between tube voltage and effective dose. 3. Therefore, it was suggested that adjusting the tube voltage for maximum image quality does not effect radiation protection. 4. This study reconfirmed the fact that increases in voltages up to 90 kV reduce skin doses. (author)

  8. Evaluation of the enter surface dose, dose in organ and E effective dose, received by personnel and patients in studies of endoscopic retrograde cholangeopancreatography in the General Hospital of Mexico; Evaluacion de la dosis de entrada superficie, dosis en organo y dosis efectiva E, recibidas por personal y pacientes en estudios de colangiopancreatografia retrograda endoscopica en el Hospital General de Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Reyes, S; Gama T, G [Calidad XXI SA de CV, Zacatecas 67-007 Col. Roma, 06700 Mexico D.F. (Mexico); Beristain, M; Espino, H [Hospital General de Mexico, Dr. Balmis 148, Col. Doctores, 06726 Mexico D.F. (Mexico)

    2006-07-01

    The ESD for patient and personal is measured: gastroenterologuist endoscopist G1, A1 Assistant and A2 instrumentist that carried out 22 independent therapeutic procedures of CPRE, in a fluoroscopy equipment Toshiba trademark with tube under the table, operated in automatic exposure mode, CAE to average tensions of 80 kVp. The measurement is carried out with film dosemeters of double emulsion Kodak Type 2 trademark, calibrated in terms of H{sup *} for the energy of the {sup 137} Cs, first it is determined the films sensitivity like function of the optical density DO, and second the ESD for the effective energy of the radiation beam (50 keV), in three different points from the dosemeter (C, D and H). The films was placed for the personnel in: right hand, front (eye), thyroid and thorax (under D and out F of the lead apron); in the case of the patient three positions were used: thorax, hepatic region and pelvis. The mean values of the ESD and it standard deviation SD in mGy units are determined by: study, personnel, film position in doctor and patient, dosemeter measurement point. The calculated doses in organ are also determined for the patient in the thorax region, liverwort and pelvis its are agreement with the NRPB SR 262 report. Finally the H{sub E} and E for medical personnel and patients are estimated demonstrating that its are not exceeded the annual dose limits for the case of the OEP. In the case of the the OEP have for the D thorax an ESD{sub max} = 0.04 mGy that one corresponds an H{sub E} = 0.02 and E = 0.01 mSv. (Author)

  9. Single dose toxicity and biodistribution studies of [18F] fluorocholine

    International Nuclear Information System (INIS)

    Campos, Danielle C.; Santos, Priscilla F.; Silveira, Marina B.; Ferreira, Soraya Z.; Malamut, Carlos; Silva, Juliana B. da; Souza, Cristina M.; Campos, Liliane C.; Ferreira, Enio; Araujo, Marina R.; Cassali, Geovanni D.

    2013-01-01

    [ 18 F]Fluorocholine ( 18 FCH) is a valuable tool for non-invasive diagnosis using positron emission tomography (PET). This radiotracer has been proven to be highly effective in detecting recurrences and staging prostate cancer, diagnoses brain, breast, and esophageal tumors and also hepatocellular carcinoma. The higher uptake of fluorocholine by malignant tumors results from increased choline kinase activity due to accelerated cell multiplication and membrane formation. According to the Brazilian Health Surveillance Agency (ANVISA), radiopharmaceuticals have to be registered before commercialization. The aim of this work was to evaluate single dose toxicity and biodistribution of 18 FCH in mice, since preclinical safety studies are required for register. Experimental procedures were approved by the Ethics Committee on Animal Use (CEUA-IPEN/SP). Single dose toxicity and biodistribution studies were conducted in Swiss mice. No signs of toxicity were observed during clinical trial. No changes in the parameters which were examined, such as: body weight, food consumption, clinical pathology parameters or lesions microscopic were noted. Biodistribution results indicated high physiological tracer uptake in kidney, liver and heart 30 min after injection. Lower activities were recorded in other organs/tissues: pancreas, intestine, spleen, bone, bladder, muscle, brain and blood. Initial preclinical investigations showed no toxic effects of 18 FCH at investigated doses and a biodistribution profile very similar to other reports in literature. This information is essential to support future human trials. (author)

  10. Evaluation of effective dose equivalent from environmental gamma rays

    International Nuclear Information System (INIS)

    Saito, K.; Tsutsumi, M.; Moriuchi, S.; Petoussi, N.; Zankl, M.; Veit, R.; Jacob, P.; Drexler, G.

    1991-01-01

    Organ doses and effective dose equivalents for environmental gamma rays were calculated using human phantoms and Monte Carlo methods accounting rigorously the environmental gamma ray fields. It was suggested that body weight is the dominant factor to determine organ doses. The weight function expressing organ doses was introduced. Using this function, the variation in organ doses due to several physical factors were investigated. A detector having gamma-ray response similar to that of human bodies has been developed using a NaI(Tl) scintillator. (author)

  11. Evaluation of six TPS algorithms in computing entrance and exit doses

    Science.gov (United States)

    Metwaly, Mohamed; Glegg, Martin; Baggarley, Shaun P.; Elliott, Alex

    2014-01-01

    Entrance and exit doses are commonly measured in in vivo dosimetry for comparison with expected values, usually generated by the treatment planning system (TPS), to verify accuracy of treatment delivery. This report aims to evaluate the accuracy of six TPS algorithms in computing entrance and exit doses for a 6 MV beam. The algorithms tested were: pencil beam convolution (Eclipse PBC), analytical anisotropic algorithm (Eclipse AAA), AcurosXB (Eclipse AXB), FFT convolution (XiO Convolution), multigrid superposition (XiO Superposition), and Monte Carlo photon (Monaco MC). Measurements with ionization chamber (IC) and diode detector in water phantoms were used as a reference. Comparisons were done in terms of central axis point dose, 1D relative profiles, and 2D absolute gamma analysis. Entrance doses computed by all TPS algorithms agreed to within 2% of the measured values. Exit doses computed by XiO Convolution, XiO Superposition, Eclipse AXB, and Monaco MC agreed with the IC measured doses to within 2%‐3%. Meanwhile, Eclipse PBC and Eclipse AAA computed exit doses were higher than the IC measured doses by up to 5.3% and 4.8%, respectively. Both algorithms assume that full backscatter exists even at the exit level, leading to an overestimation of exit doses. Despite good agreements at the central axis for Eclipse AXB and Monaco MC, 1D relative comparisons showed profiles mismatched at depths beyond 11.5 cm. Overall, the 2D absolute gamma (3%/3 mm) pass rates were better for Monaco MC, while Eclipse AXB failed mostly at the outer 20% of the field area. The findings of this study serve as a useful baseline for the implementation of entrance and exit in vivo dosimetry in clinical departments utilizing any of these six common TPS algorithms for reference comparison. PACS numbers: 87.55.‐x, 87.55.D‐, 87.55.N‐, 87.53.Bn PMID:24892349

  12. Evaluation of 1cm dose equivalent rate using a NaI(Tl) scintilation spectrometer

    International Nuclear Information System (INIS)

    Matsuda, Hideharu

    1990-01-01

    A method for evaluating 1 cm dose equivalent rates from a pulse height distribution obtained by a 76.2mmφ spherical NaI(Tl) scintillation spectrometer was described. Weak leakage radiation from nuclear facilities were also measured and dose equivalent conversion factor and effective energy of leakage radiation were evaluated from 1 cm dose equivalent rate and exposure rate. (author)

  13. Bile duct evaluation of potential living liver donors with Gd-EOB-DTPA enhanced MR cholangiography: Single-dose, double dose or half-dose contrast enhanced imaging

    Energy Technology Data Exchange (ETDEWEB)

    Kinner, Sonja, E-mail: Sonja.Kinner@uni-due.de [Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen (Germany); Steinweg, Verena [Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen (Germany); Maderwald, Stefan [Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen (Germany); Erwin L. Hahn Institute for Magnetic Resonance Imaging, Essen (Germany); Radtke, Arnold; Sotiropoulos, Georgios [Department of General Surgery, University Hospital Essen (Germany); Forsting, Michael; Schroeder, Tobias [Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen (Germany)

    2014-05-15

    Introduction: Detailed knowledge of the biliary anatomy is essential to avoid complications in living donor liver transplantation. The aim of this study was to determine the optimal dosage of Gd-EOB-DTPA for contrast-enhanced magnetic resonance cholangiography (ce-MRC) with reference to contrast-enhanced CT cholangiography (ce-CTC). Materials and methods: 30 potential living liver donors (PLLD) underwent both ce-CTC and ce-MRC. Ten candidates each received single, double or half-dose Gd-EOB-DTPA. Ce-MRC images with and without inversion recovery pulses (T1w ± IR) were acquired 20–30 min after intravenous contrast injection. Image data was quantitatively and qualitatively reviewed by two radiologists based on a on a 5-point scale. Data sets were compared using a Mann–Whitney-U-test or Wilcoxon-rank-sum-test. Kappa values were also calculated. Results: All image series provided sufficient diagnostic information both showing normal biliary anatomy and variant bile ducts. Ce-CTC showed statistically significant better results compared to all ce-MRC data sets. T1w MRC with single dose Gd-EOB-DTPA proved to be superior to half and double dose in subjective and objective evaluation without a statistically significant difference. Conclusions: Ce-MRC is at any dosage inferior to ce-CTC. As far as preoperative planning of bile duct surgery is focused on the central biliary anatomy, ce-MRC can replace harmful ce-CTC strategies, anyway. Best results were seen with single dose GD-EOB-DTPA on T1w MRC+IR.

  14. Radiation dose to the patient in radionuclide studies

    International Nuclear Information System (INIS)

    Roedler, H.D.

    1981-01-01

    In medical radionuclide studies, the radiation risk has to be considered in addition to the general risk of administering a pharmaceutical. As radiation exposure is an essential factor in radiation risk estimation, some aspects of internal dose calculation, including radiation risk assessments, are treated. The formalism of current internal dose calculation is presented. The input data, especially the residence time and the absorbed dose per transformation, their origin and accuracy are discussed. Results of internal dose calculations for the ten most frequently used radionuclide studies are presented as somatically effective dose equivalents. The accuracy of internal dose calculation is treated in detail by considering the biokinetics of the radiopharmaceutical, the phantoms used for dose calculations, the absorbed dose per transformation, the administered activity, and the transfer of the dose, calculated for a phantom, to the patient. The internal dose calculated for a reference phantom may be assumed to be in accordance with the actual patient dose within a range described by a factor of about two to three. Finally, risk estimates for nuclear medicine procedures are quantified, being generally of sixth order. The radiation risk from the radioiodine test is comparably higher, but probably lower than calculated according to the UNSCEAR risk coefficients. However, further studies are needed to confirm these preliminary results and to improve the quantification of the radiation risk from the medical use of radionuclides. (author)

  15. Radiation exposure and dose evaluation in intraoral dental radiology

    International Nuclear Information System (INIS)

    Poppe, B.; Looe, H. K.; Pfaffenberger, A.; Eenboom, F.; Chofor, N.; Sering, M.; Ruehmann, A.; Poplawski, A.; Willborn, K.

    2007-01-01

    In this study, dose area product measurements have been performed to propose diagnostic reference levels (DRLs) in intraoral dental radiology. Measurements were carried out at 60 X-ray units for all types of intraoral examinations performed in clinical routine. The third quartile values calculated range from 26.2 to 87.0 mGy cm 2 . The results showed that there exists a large difference between the patient exposures among different dental facilities. It was also observed that dentists working with faster film type or higher tube voltage are not always associated with lower exposure. The study demonstrated the necessity to have the DRLs laid out as guidelines in dental radiology. (authors)

  16. A simulation study on the dose distribution for a single beam of the gamma knife

    International Nuclear Information System (INIS)

    Chen, Chin-cheng; Jiang, Shiang-Huei; Lee, Chung-chi; Shiau, Cheng-Ying

    2000-01-01

    The purpose of this study is to evaluate the impact of the tissue heterogeneity on the dose distribution for a single beam of the gamma knife. The EGS4 Monte Carlo code was used to simulate both depth and radial profiles of the radiation dose in homogeneous and heterogeneous phantoms, respectively. The results are compared with the dose distribution calculated using the mathematical model of Gamma Plan, the treatment planning system of the gamma knife. The skull and sinus heterogeneity were simulated by a Teflon shell and an air shell, respectively. It was found that the tissue heterogeneity caused significant perturbation on the absolute depth dose at the focus as well as on the depth-dose distribution near the phantom surface and/or at the interface but little effect on the radial dose distribution. The effect of the beam aperture on the depth-dose distribution was also investigated in this study. (author)

  17. Studies of workers exposed to low doses of external radiation

    International Nuclear Information System (INIS)

    Gilbert, E.S.

    1991-04-01

    Currently, several epidemiologic studies of workers who have been exposed occupationally to low levels of radiation are being conducted, and include studies of workers in the United States, Great Britain, and Canada involved in the production of both defense materials and nuclear power. This paper focuses on studies that evaluate the possible adverse effects resulting from external exposure to radiation. The radiation risk estimates that have been used to establish radiation protection standards for workers and others have been obtained mainly from studies of persons exposed at high doses and dose rates. However, questions remain with regard to the extrapolation process that has been necessary for estimating low-level radiation risks. Occupational studies provide a direct assessment of risk based on data on persons exposed at the actual levels of interest. If current risk estimates are correct, these studies have very little chance of detecting risk, but can still be used to provide useful upper limits on risks. The studies are also adequate to detect serious underestimation of risks. 36 refs., 3 figs., 3 tabs

  18. A Comparative Evaluation of Normal Tissue Doses for Patients Receiving Radiation Therapy for Hodgkin Lymphoma on the Childhood Cancer Survivor Study and Recent Children's Oncology Group Trials

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Rachel; Ng, Angela [Department of Radiation Therapy, Princess Margaret Cancer Centre, Toronto, Ontario (Canada); Constine, Louis S. [Department of Radiation Oncology, University of Rochester, Rochester, New York (United States); Stovall, Marilyn [Division of Radiation Oncology, Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Armstrong, Gregory T. [Epidemiology/Cancer Control Department, St. Jude Children' s Research Hospital, Memphis, Tennessee (United States); Neglia, Joseph P. [Department of Pediatrics, University of Minnesota, Minneapolis, Minnesota (United States); Friedman, Debra L. [Department of Pediatrics, Vanderbilt University School of Medicine, Nashville, Tennessee (United States); Kelly, Kara [Division of Pediatric Hematology/Oncology/Stem Cell Transplant, Department of Pediatrics, Columbia University Medical Center, New York, New York (United States); FitzGerald, Thomas J. [Department of Radiation Oncology, University of Massachusetts Medical School, Worcester, Massachusetts (United States); Imaging and Radiation Oncology Core Group, Lincoln, Rhode Island (United States); Hodgson, David C., E-mail: David.hodgson@rmp.uhn.on.ca [Department of Radiation Oncology, University of Toronto, and Radiation Medicine Program, Princess Margaret Hospital, Toronto, Ontario (Canada)

    2016-06-01

    Purpose: Survivors of pediatric Hodgkin lymphoma (HL) are recognized to have an increased risk of delayed adverse health outcomes related to radiation therapy (RT). However, the necessary latency required to observe these late effects means that the estimated risks apply to outdated treatments. We sought to compare the normal tissue dose received by children treated for HL and enrolled in the Childhood Cancer Survivor Study (CCSS) (diagnosed 1970-1986) with that of patients treated in recent Children's Oncology Group (COG) trials (enrolled 2002-2012). Methods and Materials: RT planning data were obtained for 50 HL survivors randomly sampled from the CCSS cohort and applied to computed tomography planning data sets to reconstruct the normal tissue dosimetry. For comparison, the normal tissue dosimetry data were obtained for all 191 patients with full computed tomography–based volumetric RT planning on COG protocols AHOD0031 and AHOD0831. Results: For early-stage patients, the mean female breast dose in the COG patients was on average 83.5% lower than that for CCSS patients, with an absolute reduction of 15.5 Gy. For advanced-stage patients, the mean breast dose was decreased on average by 70% (11.6 Gy average absolute dose reduction). The mean heart dose decreased on average by 22.9 Gy (68.6%) and 17.6 Gy (56.8%) for early- and advanced-stage patients, respectively. All dose comparisons for breast, heart, lung, and thyroid were significantly lower for patients in the COG trials than for the CCSS participants. Reductions in the prescribed dose were a major contributor to these dose reductions. Conclusions: These are the first data quantifying the significant reduction in the normal tissue dose using actual, rather than hypothetical, treatment plans for children with HL. These findings provide useful information when counseling families regarding the risks of contemporary RT.

  19. Dosimetric evaluation of the OneDoseTM MOSFET for measuring kilovoltage imaging dose from image-guided radiotherapy procedures.

    Science.gov (United States)

    Ding, George X; Coffey, Charles W

    2010-09-01

    The purpose of this study is to investigate the feasibility of using a single-use dosimeter, OneDose MOSFET designed for in vivo patient dosimetry, for measuring the radiation dose from kilovoltage (kV) x rays resulting from image-guided procedures. The OneDose MOSFET dosimeters were precalibrated by the manufacturer using Co-60 beams. Their energy response and characteristics for kV x rays were investigated by using an ionization chamber, in which the air-kerma calibration factors were obtained from an Accredited Dosimetry Calibration Laboratory (ADCL). The dosimetric properties have been tested for typical kV beams used in image-guided radiation therapy (IGRT). The direct dose reading from the OneDose system needs to be multiplied by a correction factor ranging from 0.30 to 0.35 for kilovoltage x rays ranging from 50 to 125 kVp, respectively. In addition to energy response, the OneDose dosimeter has up to a 20% reduced sensitivity for beams (70-125 kVp) incident from the back of the OneDose detector. The uncertainty in measuring dose resulting from a kilovoltage beam used in IGRT is approximately 20%; this uncertainty is mainly due to the sensitivity dependence of the incident beam direction relative to the OneDose detector. The ease of use may allow the dosimeter to be suitable for estimating the dose resulting from image-guided procedures.

  20. Evaluation of subject contrast and normalized average glandular dose by semi-analytical models

    International Nuclear Information System (INIS)

    Tomal, A.; Poletti, M.E.; Caldas, L.V.E.

    2010-01-01

    In this work, two semi-analytical models are described to evaluate the subject contrast of nodules and the normalized average glandular dose in mammography. Both models were used to study the influence of some parameters, such as breast characteristics (thickness and composition) and incident spectra (kVp and target-filter combination) on the subject contrast of a nodule and on the normalized average glandular dose. From the subject contrast results, detection limits of nodules were also determined. Our results are in good agreement with those reported by other authors, who had used Monte Carlo simulation, showing the robustness of our semi-analytical method.

  1. Evaluation of the low dose cardiac CT imaging using ASIR technique

    Science.gov (United States)

    Fan, Jiahua; Hsieh, Jiang; Deubig, Amy; Sainath, Paavana; Crandall, Peter

    2010-04-01

    Today Cardiac imaging is one of the key driving forces for the research and development activities of Computed Tomography (CT) imaging. It requires high spatial and temporal resolution and is often associated with high radiation dose. The newly introduced ASIR technique presents an efficient method that offers the dose reduction benefits while maintaining image quality and providing fast reconstruction speed. This paper discusses the study of image quality of the ASIR technique for Cardiac CT imaging. Phantoms as well as clinical data have been evaluated to demonstrate the effectiveness of ASIR technique for Cardiac CT applications.

  2. Evaluation of the effect of patient dose from cone beam computed tomography on prostate IMRT using Monte Carlo simulation.

    Science.gov (United States)

    Chow, James C L; Leung, Michael K K; Islam, Mohammad K; Norrlinger, Bernhard D; Jaffray, David A

    2008-01-01

    The aim of this study is to evaluate the impact of the patient dose due to the kilovoltage cone beam computed tomography (kV-CBCT) in a prostate intensity-modulated radiation therapy (IMRT). The dose distributions for the five prostate IMRTs were calculated using the Pinnacle treatment planning system. To calculate the patient dose from CBCT, phase-space beams of a CBCT head based on the ELEKTA x-ray volume imaging system were generated using the Monte Carlo BEAMnr code for 100, 120, 130, and 140 kVp energies. An in-house graphical user interface called DOSCTP (DOSXYZnrc-based) developed using MATLAB was used to calculate the dose distributions due to a 360 degrees photon arc from the CBCT beam with the same patient CT image sets as used in Pinnacle. The two calculated dose distributions were added together by setting the CBCT doses equal to 1%, 1.5%, 2%, and 2.5% of the prescription dose of the prostate IMRT. The prostate plan and the summed dose distributions were then processed in the CERR platform to determine the dose-volume histograms (DVHs) of the regions of interest. Moreover, dose profiles along the x- and y-axes crossing the isocenter with and without addition of the CBCT dose were determined. It was found that the added doses due to CBCT are most significant at the femur heads. Higher doses were found at the bones for a relatively low energy CBCT beam such as 100 kVp. Apart from the bones, the CBCT dose was observed to be most concentrated on the anterior and posterior side of the patient anatomy. Analysis of the DVHs for the prostate and other critical tissues showed that they vary only slightly with the added CBCT dose at different beam energies. On the other hand, the changes of the DVHs for the femur heads due to the CBCT dose and beam energy were more significant than those of rectal and bladder wall. By analyzing the vertical and horizontal dose profiles crossing the femur heads and isocenter, with and without the CBCT dose equal to 2% of the

  3. Evaluation of the effect of patient dose from cone beam computed tomography on prostate IMRT using Monte Carlo simulation

    International Nuclear Information System (INIS)

    Chow, James C. L.; Leung, Michael K. K.; Islam, Mohammad K.; Norrlinger, Bernhard D.; Jaffray, David A.

    2008-01-01

    The aim of this study is to evaluate the impact of the patient dose due to the kilovoltage cone beam computed tomography (kV-CBCT) in a prostate intensity-modulated radiation therapy (IMRT). The dose distributions for the five prostate IMRTs were calculated using the Pinnacle3 treatment planning system. To calculate the patient dose from CBCT, phase-space beams of a CBCT head based on the ELEKTA x-ray volume imaging system were generated using the Monte Carlo BEAMnrc code for 100, 120, 130, and 140 kVp energies. An in-house graphical user interface called DOSCTP (DOSXYZnrc-based) developed using MATLAB was used to calculate the dose distributions due to a 360 deg. photon arc from the CBCT beam with the same patient CT image sets as used in Pinnacle3. The two calculated dose distributions were added together by setting the CBCT doses equal to 1%, 1.5%, 2%, and 2.5% of the prescription dose of the prostate IMRT. The prostate plan and the summed dose distributions were then processed in the CERR platform to determine the dose-volume histograms (DVHs) of the regions of interest. Moreover, dose profiles along the x- and y-axes crossing the isocenter with and without addition of the CBCT dose were determined. It was found that the added doses due to CBCT are most significant at the femur heads. Higher doses were found at the bones for a relatively low energy CBCT beam such as 100 kVp. Apart from the bones, the CBCT dose was observed to be most concentrated on the anterior and posterior side of the patient anatomy. Analysis of the DVHs for the prostate and other critical tissues showed that they vary only slightly with the added CBCT dose at different beam energies. On the other hand, the changes of the DVHs for the femur heads due to the CBCT dose and beam energy were more significant than those of rectal and bladder wall. By analyzing the vertical and horizontal dose profiles crossing the femur heads and isocenter, with and without the CBCT dose equal to 2% of the

  4. Dose response evaluation of a low-density normoxic polymer gel dosimeter using MRI

    Energy Technology Data Exchange (ETDEWEB)

    Haraldsson, P [Medical Radiation Physics, Department of Clinical Sciences, Lund University, Malmoe University Hospital, SE-205 02 Malmoe (Sweden); Department of Radiation Physics, Finsen Centre, Copenhagen University Hospital, DK-2100 Copenhagen (Denmark); Karlsson, A [Medical Radiation Physics, Department of Clinical Sciences, Lund University, Malmoe University Hospital, SE-205 02 Malmoe (Sweden); Wieslander, E [Medical Radiation Physics, Department of Clinical Sciences, Lund University Hospital, SE-221 85 Lund (Sweden); Gustavsson, H [Medical Radiation Physics, Department of Clinical Sciences, Lund University, Malmoe University Hospital, SE-205 02 Malmoe (Sweden); Baeck, S A J [Medical Radiation Physics, Department of Clinical Sciences, Lund University, Malmoe University Hospital, SE-205 02 Malmoe (Sweden)

    2006-02-21

    A low-density ({approx}0.6 g cm{sup -3}) normoxic polymer gel, containing the antioxidant tetrakis (hydroxymethyl) phosponium (THP), has been investigated with respect to basic absorbed dose response characteristics. The low density was obtained by mixing the gel with expanded polystyrene spheres. The depth dose data for 6 and 18 MV photons were compared with Monte Carlo calculations. A large volume phantom was irradiated in order to study the 3D dose distribution from a 6 MV field. Evaluation of the gel was carried out using magnetic resonance imaging. An approximately linear response was obtained for 1/T2 versus dose in the dose range of 2 to 8 Gy. A small decrease in the dose response was observed for increasing concentrations of THP. A good agreement between measured and Monte Carlo calculated data was obained, both for test tubes and the larger 3D phantom. It was shown that a normoxic polymer gel with a reduced density could be obtained by adding expanded polystyrene spheres. In order to get reliable results, it is very important to have a uniform distribution of the gel and expanded polystyrene spheres in the phantom volume.

  5. Dose response evaluation of a low-density normoxic polymer gel dosimeter using MRI

    Science.gov (United States)

    Haraldsson, P.; Karlsson, A.; Wieslander, E.; Gustavsson, H.; Bäck, S. Å. J.

    2006-02-01

    A low-density (~0.6 g cm-3) normoxic polymer gel, containing the antioxidant tetrakis (hydroxymethyl) phosponium (THP), has been investigated with respect to basic absorbed dose response characteristics. The low density was obtained by mixing the gel with expanded polystyrene spheres. The depth dose data for 6 and 18 MV photons were compared with Monte Carlo calculations. A large volume phantom was irradiated in order to study the 3D dose distribution from a 6 MV field. Evaluation of the gel was carried out using magnetic resonance imaging. An approximately linear response was obtained for 1/T2 versus dose in the dose range of 2 to 8 Gy. A small decrease in the dose response was observed for increasing concentrations of THP. A good agreement between measured and Monte Carlo calculated data was obained, both for test tubes and the larger 3D phantom. It was shown that a normoxic polymer gel with a reduced density could be obtained by adding expanded polystyrene spheres. In order to get reliable results, it is very important to have a uniform distribution of the gel and expanded polystyrene spheres in the phantom volume.

  6. Comparison between evaluating methods about the protocols of different dose distributions in radiotherapy

    International Nuclear Information System (INIS)

    Ju Yongjian; Chen Meihua; Sun Fuyin; Zhang Liang'an; Lei Chengzhi

    2004-01-01

    Objective: To study the relationship between tumor control probability (TCP) or equivalent uniform dose (EUD) and the heterogeneity degree of the dose changes with variable biological parameter values of the tumor. Methods: According to the definitions of TCP and EUD, calculating equations were derived. The dose distributions in the tumor were assumed to be Gaussian ones. The volume of the tumor was divided into several voxels, and the absorbed doses of these voxels were simulated by Monte Carlo methods. Then with the different values of radiosensitivity (α) and potential doubling time of the clonogens (T p ), the relationships between TCP or EUD and the standard deviation of dose (S d ) were evaluated. Results: The TCP-S d curves were influenced by the variable α and T p values, but the EUD-S d curves showed little variation. Conclusion: When the radiotherapy protocols with different dose distributions are compared, if the biological parameter values of the tumor have been known exactly, it's better to use the TCP, otherwise the EUD will be preferred

  7. An evaluation of the impact of digital imaging on radiographic practice and patient doses

    Science.gov (United States)

    Horrocks, J.; Violaki, K.

    2015-09-01

    Direct digital imaging technology was implemented in all areas in general and mobile radiology at Barts and the Royal London Hospitals in 2012. Evidence from recent radiation incident investigations indicates optimum exposure factors are not consistently selected, with the greater dynamic range of the digital detectors allowing sub-optimal practice. To investigate further patient dose data were extracted from the Radiology Information System for adult chest X-ray examinations in 2014, covering over 50,000 studies in the Trust. Chest X-ray examinations were selected as they are low dose but frequent examinations. The patient dose data were evaluated taking into account X-ray system type and detector performance measurements, and individual cases studies were used to highlight where practice can be improved.

  8. Social-demographic profile and dose evaluation of the radiopharmaceutical facility workers

    International Nuclear Information System (INIS)

    Sanches, Matias P.; Carneiro, Janete C. Gaburo; Sordi, Gian Maria A.A.

    2009-01-01

    The main aims of this work are to identify the social-demographic profile of the workers based on stratification variables such as gender, age, and tasks performed by the workers, and to evaluate the annual collective doses of workers with potential risk of ionizing radiation exposure at the workplace during the years 2004 to 2008. In this context, the knowledge of the workforce composition in the facility responsible for the radioisotope production and its distribution was used. The individual monitoring programme has been carried out by individual dosimeters, TLDs, and internal contamination monitoring (in vivo method). The reported doses, in the period studied, suggest that the external exposure was the main source of occupational exposure in radioisotope production and distribution areas. The internal exposure was not included in the doses estimated, because it was negligible. This study has an important exploratory character, in order to analyze possible correlations related to adverse health effects, aiming to provide directions for occupational epidemiology research. (author)

  9. Evaluation of sphingolipids in Wistar rats treated to prolonged and single oral doses of fumonisin b₁.

    Science.gov (United States)

    Direito, Glória M; Almeida, Adriana P; Aquino, Simone; dos Reis, Tatiana Alves; Pozzi, Claudia Rodrigues; Corrêa, Benedito

    2009-01-01

    The objective of the present study was to evaluate sphingolipid levels (sphingosine-So and sphinganine-Sa) and to compare the Sa/So ratio in liver, serum and urine of Wistar rats after prolonged administration (21 days) of fumonisin B(1) (FB(1)). In parallel, the kinetics of sphingolipid elimination in urine was studied in animals receiving a single dose of FB(1). Prolonged exposure to FB(1) caused an increase in Sa levels in urine, serum and liver. The most marked effect on sphingolipid biosynthesis was observed in animals treated with the highest dose of FB(1). Animals receiving a single dose of FB(1) presented variations in Sa and So levels and in the Sa/So ratio.

  10. Social-demographic profile and dose evaluation of the radiopharmaceutical facility workers

    Energy Technology Data Exchange (ETDEWEB)

    Sanches, Matias P.; Carneiro, Janete C. Gaburo; Sordi, Gian Maria A.A. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)], e-mail: msanches@ipen.br

    2009-07-01

    The main aims of this work are to identify the social-demographic profile of the workers based on stratification variables such as gender, age, and tasks performed by the workers, and to evaluate the annual collective doses of workers with potential risk of ionizing radiation exposure at the workplace during the years 2004 to 2008. In this context, the knowledge of the workforce composition in the facility responsible for the radioisotope production and its distribution was used. The individual monitoring programme has been carried out by individual dosimeters, TLDs, and internal contamination monitoring (in vivo method). The reported doses, in the period studied, suggest that the external exposure was the main source of occupational exposure in radioisotope production and distribution areas. The internal exposure was not included in the doses estimated, because it was negligible. This study has an important exploratory character, in order to analyze possible correlations related to adverse health effects, aiming to provide directions for occupational epidemiology research. (author)

  11. Organ doses in interventional radiology procedures: Evaluation of software

    International Nuclear Information System (INIS)

    Tort, I.; Ruiz-Cruces, R.; Perez-Martinez, M.; Carrera, F.; Ojeda, C.; Diez de los Rios, A.

    2001-01-01

    Interventional Radiology (IR) procedures require large fluoroscopy times and important number of radiological images, so the levels of radiation to patient are high, which leads us to calculate the organ doses. The objective of this work is to estimate and make a comparison of the results given by the different software that we have to do the calculation of organ doses in complex procedures of IR. To do this, 28 patients have been selected, distributed in the 3 procedures with highest doses. The determination of organ doses and effective doses has been made using the projections utilized and different software based on Monte Carlo Methods: Eff-dose, PCXMC and Diasoft. We have obtained very high dispersion in the average organ dose between the 3 programs. In many cases, it is higher than 25% and in some particular cases, it is greater than 100%. Dispersion obtained in effective doses is not so high, being under 20% in all cases. This shows that a better solution is needed to solve the problem of the organ doses calculation; a more accurate method is necessary that brings us to a trustworthy approach to reality, and, at the moment, that we do not dispose of it. (author)

  12. Evaluation of an electron Monte Carlo dose calculation algorithm for treatment planning.

    Science.gov (United States)

    Chamberland, Eve; Beaulieu, Luc; Lachance, Bernard

    2015-05-08

    The purpose of this study is to evaluate the accuracy of the electron Monte Carlo (eMC) dose calculation algorithm included in a commercial treatment planning system and compare its performance against an electron pencil beam algorithm. Several tests were performed to explore the system's behavior in simple geometries and in configurations encountered in clinical practice. The first series of tests were executed in a homogeneous water phantom, where experimental measurements and eMC-calculated dose distributions were compared for various combinations of energy and applicator. More specifically, we compared beam profiles and depth-dose curves at different source-to-surface distances (SSDs) and gantry angles, by using dose difference and distance to agreement. Also, we compared output factors, we studied the effects of algorithm input parameters, which are the random number generator seed, as well as the calculation grid size, and we performed a calculation time evaluation. Three different inhomogeneous solid phantoms were built, using high- and low-density materials inserts, to clinically simulate relevant heterogeneity conditions: a small air cylinder within a homogeneous phantom, a lung phantom, and a chest wall phantom. We also used an anthropomorphic phantom to perform comparison of eMC calculations to measurements. Finally, we proceeded with an evaluation of the eMC algorithm on a clinical case of nose cancer. In all mentioned cases, measurements, carried out by means of XV-2 films, radiographic films or EBT2 Gafchromic films. were used to compare eMC calculations with dose distributions obtained from an electron pencil beam algorithm. eMC calculations in the water phantom were accurate. Discrepancies for depth-dose curves and beam profiles were under 2.5% and 2 mm. Dose calculations with eMC for the small air cylinder and the lung phantom agreed within 2% and 4%, respectively. eMC calculations for the chest wall phantom and the anthropomorphic phantom also

  13. Evaluation of patient absorbed dose in a PET-CT test

    International Nuclear Information System (INIS)

    Guerra P, F.; Mourao F, A. P.; Santana, P. C.

    2017-10-01

    Images of PET-CT has important diagnostic applications, especially in oncology. This equipment allows overlapping of functional images obtained from the administration of radionuclides and anatomical, generated by X-rays. The PET-CT technique may generate higher doses in patients due to the fact that two diagnostic modalities are used in a single examination. A whole body CT scan is performed and in sequence, a capture of the signal generated by the photons emitted is done. In this study, the absorbed and effective doses generated by the CT scan and incorporated by the administration of the radionuclide were evaluated in 19 organs. To evaluate the CT dose, 32 radiochromic film strips were correctly positioned into the anthropomorphic male phantom. The CT protocol performed was whole-body scanning and a high-resolution lung scan. This protocol is currently used in most services. The calculation of the effective dose from the injected activity in the patient was performed using the ICRP 106 Biokinetic model (ICRP 106, 2008). The activity to be injected may vary according to the patients body mass and with the sensitivity of the detector. The mass of the simulator used is 73.5 kg, then the simulation with and injected activity of 244.76 MBq was used. It was observed that 87.4% of the effective dose in examination PET/CT comes from the CT scans, being 63.8% of the whole body scan and 23.6% of high resolution lung scan. Using activity of 0.09 mCi x kg 18 F-FDG radiopharmaceutical contributes only 12.6% of the final effective dose. As a conclusion, it was observed that the dose in patients submitted to the 18 F-FDG PET-CT examination is high, being of great value efforts for its reduction, such as the use of appropriate image acquisition techniques and promoting the application of the principle of optimization of practice. (Author)

  14. A new study on the effects of low doses

    International Nuclear Information System (INIS)

    Dousset, M.; Jammet, H.

    1986-01-01

    A study conducted by prof. Rose has investigated mortality among 39540 employees of the UKAEA, from 1946 to 1978. The three main points are: 1. General mortality and mortality from malignant diseases are lower than in the population of England and Wales (74 and 79 per cent respectively), thus showing no major difference between workers monitored for exposure to radiation and other workers. 2. For monitored workers, the only death cause for which there is a statistically significant correlation with radiation exposure is prostate cancer; there are many cases especially in workers with doses exceeding 0.05 Sv (5 rem) and monitored for tritium. Such a correlation has never been found in any other epidemiologic survey of workers exposed to low-level doses, Hanford (USA) workers especially; conversely, mortality from either multiple myeloma or pancreas cancer is not found here. These facts plead for a cautious interpretation of the results as a whole. 3. A linear representation of the variations of leukemia and cancer mortality vs exposure results in lines, the slopes of which are 3 times higher than those of the lines adopted by ICRP; however, the 95% confidence intervals (-2.7 + 12.4 and -22 + 52.5) are such that the results are compatible with a null effect (slope 0) and even with a benefic effect (negative slope). They are therefore compatible with ICRP estimations. A recent attempt to evaluate the two main investigations on low-dose occupational exposures (UKAEA and Hanford) suggests a dose-response relationship very near that of ICRP [fr

  15. Dosimetry in computerized tomography and evaluation of doses in organs in thorax scanning

    International Nuclear Information System (INIS)

    Alonso, Thêssa Cristina

    2016-01-01

    Computed tomography has promoted improvement of the diagnostic process by producing anatomical cut images with high quality and contrast between soft tissues which have very similar absorption of the X-ray beams. The objective of this study is to evaluate the technological park of CT in Brazil correlated with the wide world, and carry out studies of experimental dosimetry to understand the dose distribution feature using phantoms and different methods of measurement of kerma index, as well as perform measures of local doses in sensitive organs. To study the scanner geographic distribution and supply of computed tomography tests in Brazil, a comparison has been made with results found with the specified reference by Brazilian law (Ordinance GM / MS No. 1101, 2002; Resolution RE nº1016, 2006). For dosimetry studies, It was used a standard chest phantom and the anthropomorphic phantom. For image quality evaluation, it was used the CATPHAN-600 phantom. Scans were performed in a GE scanner, Discovery model with 64 channels. Dose measurements have been performed by using a pencil ionization chamber, thermoluminescent dosimeters and radiochromic film strips. Sensitive organ shielding devices were evaluated in order to verify their efficiency in organ dose reduction and its influence in the quality of image. Considering Brazilian population, the scanner park showed a greater amount than the minimum parameter recommended by Brazilian law. Dose measurements using three different methods showed the correct procedure of metrological reliability of the measurement system. The findings and conclusions of this study may contribute to the improvement of local practices in Computed Tomography tests, inserted in context of radiological protection in order to define reference levels for optimized diagnosis, and image quality control. (author)

  16. SU-E-T-161: Evaluation of Dose Calculation Based On Cone-Beam CT

    International Nuclear Information System (INIS)

    Abe, T; Nakazawa, T; Saitou, Y; Nakata, A; Yano, M; Tateoka, K; Fujimoto, K; Sakata, K

    2014-01-01

    Purpose: The purpose of this study is to convert pixel values in cone-beam CT (CBCT) using histograms of pixel values in the simulation CT (sim-CT) and the CBCT images and to evaluate the accuracy of dose calculation based on the CBCT. Methods: The sim-CT and CBCT images immediately before the treatment of 10 prostate cancer patients were acquired. Because of insufficient calibration of the pixel values in the CBCT, it is difficult to be directly used for dose calculation. The pixel values in the CBCT images were converted using an in-house program. A 7 fields treatment plans (original plan) created on the sim-CT images were applied to the CBCT images and the dose distributions were re-calculated with same monitor units (MUs). These prescription doses were compared with those of original plans. Results: In the results of the pixel values conversion in the CBCT images,the mean differences of pixel values for the prostate,subcutaneous adipose, muscle and right-femur were −10.78±34.60, 11.78±41.06, 29.49±36.99 and 0.14±31.15 respectively. In the results of the calculated doses, the mean differences of prescription doses for 7 fields were 4.13±0.95%, 0.34±0.86%, −0.05±0.55%, 1.35±0.98%, 1.77±0.56%, 0.89±0.69% and 1.69±0.71% respectively and as a whole, the difference of prescription dose was 1.54±0.4%. Conclusion: The dose calculation on the CBCT images achieve an accuracy of <2% by using this pixel values conversion program. This may enable implementation of efficient adaptive radiotherapy

  17. Analytical evaluation of dose measurement of critical accident at SILENE (Contract research)

    CERN Document Server

    Nakamura, T; Tonoike, K

    2003-01-01

    Institute for Radioprotection and Nuclear Safety (IRSN) and the OECD Nuclear Energy Agency (NEA) jointly organized SILENE Accident Dosimetry Intercomparison Exercise to intercompare the dose measurement systems of participating countries. Each participating country carried out dose measurements in the same irradiation field, and the measurement results were mutually compared. The participated in the exercise to measure the doses of gamma rays and neutron from SILENE by using thermoluminescence dosimeters (TLD's) and an alanine dosimeter. In this examination, the derived evaluation formulae for obtaining a tissue-absorbed dose from measured value (ambient dose equivalent) of TLD for neutron. We reported the tissue-absorbed dose computed using this evaluation formula to OECD/NEA. TLD's for neutron were irradiated in the TRACY facility to verify the evaluation formulae. The results of TLD's were compared with the calculations of MCNP and measurements with alanine dose meter. We found that the ratio of the dose b...

  18. Evaluation of glandular dose in conventional and digital mammography systems

    International Nuclear Information System (INIS)

    Coutinho, Celia Maria Campos

    2009-01-01

    A survey was conducted to estimate the average glandular dose (D g ) for patients undergoing mammography and to report the distribution of incident air kerma (K i ), patient age, compressed breast thickness and glandular tissue content. From 1183 cranio caudal mammograms clinical data were collected and doses were measured. The survey data included mammograms from six mammography equipment: two screen/film units (SFM), two computed radiography units (CR) and two full-field digital (DR). Mean value for patient age and compressed breast thickness were 57 +-12 y and 5.4 +-1.4 cm, respectively. To investigate the importance of technical characteristics of three different mammography systems and breast glandularity, K i and D g were measured for individual breast of 392 patients from the original sample with compressed breast thickness in the range of 5.5 cm to 6.5 cm using tissue-equivalent phantoms of different glandularities manufactured in this study to mimic both the attenuation and the density of breast tissues. Mean K i value was 10.0 +-3.6 mGy for SFM systems, 12.0 +-3.6 mGy for CR systems and 4.9 +-1.3 mGy for DR systems. Mean D g value was 1.4 +-0.5 mGy for S/F systems, 1.7 +-0.5 mGy for CR systems and 0.9 +-0.2 mGy for D R systems. Statistical analysis for differences in mean values of K i and D g between mammography systems showed significant effect of their technical characteristics (p i and D g , it was observed statistically significant differences between the group of patients with 0 to 50% glandularity and the group of patients with 50 to 100% glandularity. (author)

  19. Evaluation of dose prediction errors and optimization convergence errors of deliverable-based head-and-neck IMRT plans computed with a superposition/convolution dose algorithm

    International Nuclear Information System (INIS)

    Mihaylov, I. B.; Siebers, J. V.

    2008-01-01

    The purpose of this study is to evaluate dose prediction errors (DPEs) and optimization convergence errors (OCEs) resulting from use of a superposition/convolution dose calculation algorithm in deliverable intensity-modulated radiation therapy (IMRT) optimization for head-and-neck (HN) patients. Thirteen HN IMRT patient plans were retrospectively reoptimized. The IMRT optimization was performed in three sequential steps: (1) fast optimization in which an initial nondeliverable IMRT solution was achieved and then converted to multileaf collimator (MLC) leaf sequences; (2) mixed deliverable optimization that used a Monte Carlo (MC) algorithm to account for the incident photon fluence modulation by the MLC, whereas a superposition/convolution (SC) dose calculation algorithm was utilized for the patient dose calculations; and (3) MC deliverable-based optimization in which both fluence and patient dose calculations were performed with a MC algorithm. DPEs of the mixed method were quantified by evaluating the differences between the mixed optimization SC dose result and a MC dose recalculation of the mixed optimization solution. OCEs of the mixed method were quantified by evaluating the differences between the MC recalculation of the mixed optimization solution and the final MC optimization solution. The results were analyzed through dose volume indices derived from the cumulative dose-volume histograms for selected anatomic structures. Statistical equivalence tests were used to determine the significance of the DPEs and the OCEs. Furthermore, a correlation analysis between DPEs and OCEs was performed. The evaluated DPEs were within ±2.8% while the OCEs were within 5.5%, indicating that OCEs can be clinically significant even when DPEs are clinically insignificant. The full MC-dose-based optimization reduced normal tissue dose by as much as 8.5% compared with the mixed-method optimization results. The DPEs and the OCEs in the targets had correlation coefficients greater

  20. Evaluation of indoor radon equilibrium factor using CFD modeling and resulting annual effective dose

    Science.gov (United States)

    Rabi, R.; Oufni, L.

    2018-04-01

    The equilibrium factor is an important parameter for reasonably estimating the population dose from radon. However, the equilibrium factor value depended mainly on the ventilation rate and the meteorological factors. Therefore, this study focuses on investigating numerically the influence of the ventilation rate, temperature and humidity on equilibrium factor between radon and its progeny. The numerical results showed that ventilation rate, temperature and humidity have significant impacts on indoor equilibrium factor. The variations of equilibrium factor with the ventilation, temperature and relative humidity are discussed. Moreover, the committed equivalent doses due to 218Po and 214Po radon short-lived progeny were evaluated in different tissues of the respiratory tract of the members of the public from the inhalation of indoor air. The annual effective dose due to radon short lived progeny from the inhalation of indoor air by the members of the public was investigated.

  1. Evaluation of the breast absorbed dose distribution using the Fricke Xylenol Gel

    International Nuclear Information System (INIS)

    Czelusniak, C; Del Lama, L S; Moreira, M V; De Almeida, A

    2010-01-01

    During a breast cancer radiotherapy treatment, several issues have to be taken into account, among them, hot spots, gradient of doses delivered over the breast, as well as in the lungs and the heart. The present work aims to apply the Fricke Xylenol Gel (FXG) dosimeter in the study of these issues, using a CCD camera to analyse the dose deposited distribution. Thus, the CCD was used to capture the images of different cuvettes that were filled with FXG and irradiated considering analogous setups employed in breast cancer radiotherapy treatments. Thereafter, these pictures where processed in a MatLab routine and the spatial dose distributions could be evaluated. These distributions were compared with the ones that were obtained from dedicated treatment planning's softwares. According to the results obtained, the FXG, allied with the CCD system, has shown to be a complementary tool in dosimetry, helping to prevent possible complications during breast cancer treatments.

  2. Evaluation of the breast absorbed dose distribution using the Fricke Xylenol Gel

    Energy Technology Data Exchange (ETDEWEB)

    Czelusniak, C; Del Lama, L S; Moreira, M V; De Almeida, A, E-mail: dalmeida@ffclrp.usp.b

    2010-11-01

    During a breast cancer radiotherapy treatment, several issues have to be taken into account, among them, hot spots, gradient of doses delivered over the breast, as well as in the lungs and the heart. The present work aims to apply the Fricke Xylenol Gel (FXG) dosimeter in the study of these issues, using a CCD camera to analyse the dose deposited distribution. Thus, the CCD was used to capture the images of different cuvettes that were filled with FXG and irradiated considering analogous setups employed in breast cancer radiotherapy treatments. Thereafter, these pictures where processed in a MatLab routine and the spatial dose distributions could be evaluated. These distributions were compared with the ones that were obtained from dedicated treatment planning's softwares. According to the results obtained, the FXG, allied with the CCD system, has shown to be a complementary tool in dosimetry, helping to prevent possible complications during breast cancer treatments.

  3. Intradermal Inactivated Poliovirus Vaccine: A Preclinical Dose-Finding Study

    OpenAIRE

    Kouiavskaia, Diana; Mirochnitchenko, Olga; Dragunsky, Eugenia; Kochba, Efrat; Levin, Yotam; Troy, Stephanie; Chumakov, Konstantin

    2014-01-01

    Intradermal delivery of vaccines has been shown to result in dose sparing. We tested the ability of fractional doses of inactivated poliovirus vaccine (IPV) delivered intradermally to induce levels of serum poliovirus-neutralizing antibodies similar to immunization through the intramuscular route. Immunogenicity of fractional doses of IPV was studied by comparing intramuscular and intradermal immunization of Wistar rats using NanoPass MicronJet600 microneedles. Intradermal delivery of partial...

  4. A model to incorporate organ deformation in the evaluation of dose/volume relationship

    International Nuclear Information System (INIS)

    Yan, D.; Jaffray, D.; Wong, J.; Brabbins, D.; Martinez, A. A.

    1997-01-01

    Purpose: Measurements of internal organ motion have demonstrated that daily organ deformation exists during the course of radiation treatment. However, a model to evaluate the resultant dose delivered to a daily deformed organ remains a difficult challenge. Current methods which model such organ deformation as rigid body motion in the dose calculation for treatment planning evaluation are incorrect and misleading. In this study, a new model for treatment planning evaluation is introduced which incorporates patient specific information of daily organ deformation and setup variation. The model was also used to retrospectively analyze the actual treatment data measured using daily CT scans for 5 patients with prostate treatment. Methods and Materials: The model assumes that for each patient, the organ of interest can be measured during the first few treatment days. First, the volume of each organ is delineated from each of the daily measurements and cumulated in a 3D bit-map. A tissue occupancy distribution is then constructed with the 50% isodensity representing the mean, or effective, organ volume. During the course of treatment, each voxel in the effective organ volume is assumed to move inside a local 3D neighborhood with a specific distribution function. The neighborhood and the distribution function are deduced from the positions and shapes of the organ in the first few measurements using the biomechanics model of viscoelastic body. For each voxel, the local distribution function is then convolved with the spatial dose distribution. The latter includes also the variation in dose due to daily setup error. As a result, the cumulative dose to the voxel incorporates the effects of daily setup variation and organ deformation. A ''variation adjusted'' dose volume histogram, aDVH, for the effective organ volume can then be constructed for the purpose of treatment evaluation and optimization. Up to 20 daily CT scans and daily portal images for 5 patients with prostate

  5. A single institution study of radiation dose received from CT imaging: A comparison to Malaysian NDRL

    Science.gov (United States)

    Osman, N. D.; Shamsuri, S. B. M.; Tan, Y. W.; Razali, M. A. S. M.; Isa, S. M.

    2017-05-01

    Advancement of CT technology has led to an increase in CT scanning as it improves the diagnosis. However, it is important to assess health risk of patients associated with ionising radiation received from CT. This study evaluated current dose distributions at Advanced Medical and Dental Institute (AMDI), Malaysia and was used to establish Local Diagnostic Reference Level (LDRL). Dose indicators such as CT Dose Index (CTDIvol and CTDIw) and Dose-Length Product (DLP) were gathered for all routine CT examinations performed at the Imaging Unit, AMDI from January 2015 to June 2016. The first and third quartile values for each dose indicator were determined. A total of 364 CT studies were performed during that period with the highest number of cases being Thorax-Abdomen-Pelvis (TAP) study (57% of total study). The CTDIw ranged between 2.0 mGy to 23.4 mGy per procedure. DLP values were ranged between 94 mGy.cm to 1687 mGy.cm. The local dose data was compared with the national DRL to monitor the current CT practice at AMDI and LDRL will be established from the calculated third quartile values of dose distribution. From the results, some of the local dose values exceeded the Malaysian and further evaluation is important to ensure the dose optimisation for patients.

  6. A single institution study of radiation dose received from CT imaging: A comparison to Malaysian NDRL

    International Nuclear Information System (INIS)

    Osman, N D; Shamsuri, S B M; Razali, M A S M; Isa, S M; Tan, Y W

    2017-01-01

    Advancement of CT technology has led to an increase in CT scanning as it improves the diagnosis. However, it is important to assess health risk of patients associated with ionising radiation received from CT. This study evaluated current dose distributions at Advanced Medical and Dental Institute (AMDI), Malaysia and was used to establish Local Diagnostic Reference Level (LDRL). Dose indicators such as CT Dose Index (CTDI vol and CTDI w ) and Dose-Length Product (DLP) were gathered for all routine CT examinations performed at the Imaging Unit, AMDI from January 2015 to June 2016. The first and third quartile values for each dose indicator were determined. A total of 364 CT studies were performed during that period with the highest number of cases being Thorax-Abdomen-Pelvis (TAP) study (57% of total study). The CTDI w ranged between 2.0 mGy to 23.4 mGy per procedure. DLP values were ranged between 94 mGy.cm to 1687 mGy.cm. The local dose data was compared with the national DRL to monitor the current CT practice at AMDI and LDRL will be established from the calculated third quartile values of dose distribution. From the results, some of the local dose values exceeded the Malaysian and further evaluation is important to ensure the dose optimisation for patients. (paper)

  7. Evaluation of absorbed doses during irradiation of patients

    International Nuclear Information System (INIS)

    Denisenko, O.N.; Kozlov, V.A.

    1981-01-01

    Provided is an analysis of a general scheme for the method of control over the dose field realization in the patient's body using direct dose measurements in patients. On the basis of data from literature presented are error limits in the stages of preradiation preparation and irradiation of patients, and in the stage of dose measurement for different irradiation techniques and radiation types. The authors also provide scientific data of their own. It has been concluded that the main emphasis should be placed on the improvement of topometry facilities, field calculation, patients posture and visual control methods of the radiation beam position [ru

  8. A method to evaluate the dose increase in CT with iodinated contrast medium

    International Nuclear Information System (INIS)

    Amato, Ernesto; Lizio, Domenico; Settineri, Nicola; Di Pasquale, Andrea; Salamone, Ignazio; Pandolfo, Ignazio

    2010-01-01

    Purpose: The objective of this study is to develop a method to calculate the relative dose increase when a computerized tomography scan (CT) is carried out after administration of iodinated contrast medium, with respect to the same CT scan in absence of contrast medium. Methods: A Monte Carlo simulation in GEANT4 of anthropomorphic neck and abdomen phantoms exposed to a simplified model of CT scanner was set up in order to calculate the increase of dose to thyroid, liver, spleen, kidneys, and pancreas as a function of the quantity of iodine accumulated; a series of experimental measurements of Hounsfield unit (HU) increment for known concentrations of iodinated contrast medium was carried out on a Siemens Sensation 16 CT scanner in order to obtain a relationship between the increment in HU and the relative dose increase in the organs studied. The authors applied such a method to calculate the average dose increase in three patients who underwent standard CT protocols consisting of one native scan in absence of contrast, followed by a contrast-enhanced scan in venous phase. Results: The authors validated their GEANT4 Monte Carlo simulation by comparing the resulting dose increases for iodine solutions in water with the ones presented in literature and with their experimental data obtained through a Roentgen therapy unit. The relative dose increases as a function of the iodine mass fraction accumulated and as a function of the Hounsfield unit increment between the contrast-enhanced scan and the native scan are presented. The data shown for the three patients exhibit an average relative dose increase between 22% for liver and 74% for kidneys; also, spleen (34%), pancreas (28%), and thyroid (48%) show a remarkable average increase. Conclusions: The method developed allows a simple evaluation of the dose increase when iodinated contrast medium is used in CT scans, basing on the increment in Hounsfield units observed on the patients' organs. Since many clinical protocols

  9. A method to evaluate the dose increase in CT with iodinated contrast medium

    Energy Technology Data Exchange (ETDEWEB)

    Amato, Ernesto; Lizio, Domenico; Settineri, Nicola; Di Pasquale, Andrea; Salamone, Ignazio; Pandolfo, Ignazio [Department of Radiological Sciences, University of Messina, Messina 98125 (Italy); Department of Physics, University of Messina, Messina 98166 (Italy); University Hospital ' ' G. Martino' ' , Messina 98125 (Italy); Department of Radiological Sciences, University of Messina, Messina 98125 (Italy) and University Hospital ' ' G. Martino' ' , Messina 98125 (Italy)

    2010-08-15

    Purpose: The objective of this study is to develop a method to calculate the relative dose increase when a computerized tomography scan (CT) is carried out after administration of iodinated contrast medium, with respect to the same CT scan in absence of contrast medium. Methods: A Monte Carlo simulation in GEANT4 of anthropomorphic neck and abdomen phantoms exposed to a simplified model of CT scanner was set up in order to calculate the increase of dose to thyroid, liver, spleen, kidneys, and pancreas as a function of the quantity of iodine accumulated; a series of experimental measurements of Hounsfield unit (HU) increment for known concentrations of iodinated contrast medium was carried out on a Siemens Sensation 16 CT scanner in order to obtain a relationship between the increment in HU and the relative dose increase in the organs studied. The authors applied such a method to calculate the average dose increase in three patients who underwent standard CT protocols consisting of one native scan in absence of contrast, followed by a contrast-enhanced scan in venous phase. Results: The authors validated their GEANT4 Monte Carlo simulation by comparing the resulting dose increases for iodine solutions in water with the ones presented in literature and with their experimental data obtained through a Roentgen therapy unit. The relative dose increases as a function of the iodine mass fraction accumulated and as a function of the Hounsfield unit increment between the contrast-enhanced scan and the native scan are presented. The data shown for the three patients exhibit an average relative dose increase between 22% for liver and 74% for kidneys; also, spleen (34%), pancreas (28%), and thyroid (48%) show a remarkable average increase. Conclusions: The method developed allows a simple evaluation of the dose increase when iodinated contrast medium is used in CT scans, basing on the increment in Hounsfield units observed on the patients' organs. Since many clinical

  10. Visual Perception Studies in CT images obtained lo low dose

    International Nuclear Information System (INIS)

    Adame Brooks, D.; Miller-Clemente, R. A.

    2015-01-01

    This paper has as aims to describe a strategy to evaluate the diagnostic quality of obtained images of method for dose reduction, with the purpose of determining the dose value or values from which the image quality is significantly degraded making it insufficient for the diagnostic. To complement and have an estimate of the quality of the images we established a group of measures of objective type, and the diagnostic quality of the images was evaluated through a group of observers using the analysis ROC and LROC. For ROC and LROC analyzes the behavior of the area under the curve in relation to the four proposed dose levels was obtained. For high dose levels, detection was good. The values of area under the curve decreased as the dose rate decreased, falling to values indicating low accuracy in diagnosis. This result indicates that the area under the curve decreases by the dose rate. We conclude that the objective quality measures selected are representative of the changes that occur in the resulting image and provided information on changes in the perception of observers. The experiments ROC and LROC allowed determine the range of dose values from which the image degradation causes a low accuracy in the diagnostic. (Author)

  11. 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)

  12. Intradermal inactivated poliovirus vaccine: a preclinical dose-finding study.

    Science.gov (United States)

    Kouiavskaia, Diana; Mirochnitchenko, Olga; Dragunsky, Eugenia; Kochba, Efrat; Levin, Yotam; Troy, Stephanie; Chumakov, Konstantin

    2015-05-01

    Intradermal delivery of vaccines has been shown to result in dose sparing. We tested the ability of fractional doses of inactivated poliovirus vaccine (IPV) delivered intradermally to induce levels of serum poliovirus-neutralizing antibodies similar to immunization through the intramuscular route. Immunogenicity of fractional doses of IPV was studied by comparing intramuscular and intradermal immunization of Wistar rats using NanoPass MicronJet600 microneedles. Intradermal delivery of partial vaccine doses induced antibodies at titers comparable to those after immunization with full human dose delivered intramuscularly. The results suggest that intradermal delivery of IPV may lead to dose-sparing effect and reduction of the vaccination cost. Published by Oxford University Press on behalf of the Infectious Diseases Society of America 2014. This work is written by (a) US Government employee(s) and is in the public domain in the US.

  13. Study of teflon pads as high doses dosemeters

    International Nuclear Information System (INIS)

    Teixeira, Maria Ines; Caldas, Linda V.E.

    2013-01-01

    The aim of this work is to study the Teflon, which is used as a binder in the manufacture of dosimetric tablets, for the feasibility of this material as high dose dosemeter. In this paper we used the technique of thermally stimulated luminescence (OSL) to characterize the dosimetric properties of Teflon. Teflon samples were exposed to different doses of radiation, using a source of gamma radiation ( 60 Co). It was obtained dose-response curve between 100 Gy to 50 kGy and reproducibility of OSL response. The preliminary results show that Teflon is a useful material to high dose dosimetry

  14. A double-blind, placebo-controlled, randomised, parallel-group, dose-escalating, repeat dose study in healthy volunteers to evaluate the safety, tolerability, pharmacodynamic effects and pharmacokinetics of the once daily rectal application of NRL001 suppositories for 14 days.

    Science.gov (United States)

    Bell, D; Duffin, A; Jacobs, A; Pediconi, C; Gruss, H J

    2014-03-01

    The 1R,2S stereoisomer of methoxamine hydrochloride, NRL001, is a highly selective α1-adrenoceptor agonist being developed for the local treatment of non-structural faecal incontinence caused by weak internal anal sphincter tone. This study investigated the steady state pharmacokinetics (PK) and safety of 2 g rectal suppositories containing NRL001 in different strengths (7.5, 10, 12.5 or 15 mg). Healthy volunteers aged 18-45 years received 14 daily doses of NRL001 2 g suppositories or matching placebo. In each dose group nine participants received NRL001 and three received placebo. Blood samples to determine NRL001 concentrations were taken on Days 1, 7 and 14. Cardiovascular parameters were collected via electrocardiograms, Holter monitoring (three lead Holter monitor) and vital signs. Forty-eight volunteers were enrolled; 43 completed the study and were included in the PK analysis population. AUC and Cmax broadly increased with increasing dose, Tmax generally occurred between 4.0 and 5.0 h. Although the data did not appear strongly dose proportional, dose proportionality analysis did not provide evidence against dose proportionality as the log(dose) coefficients were not significantly < 1. NRL001 did not accumulate over time for any dose. Increasing NRL001 concentrations were related to changes in vital sign variables, most notably decreased heart rate. The most commonly reported adverse events (AEs) in the active treatment groups were paraesthesia and piloerection. Treatment with NRL001 was generally well tolerated over 14 days once daily dosing and plasma NRL001 did not accumulate over time. Treatment was associated with changes in vital sign variables, most notably decreased heart rate. AEs commonly reported with NRL001 treatment were events indicative of a systemic α-adrenergic effect. Colorectal Disease © 2014 The Association of Coloproctology of Great Britain and Ireland.

  15. Evaluation of low dose ionizing radiation effect on some blood components in animal model

    OpenAIRE

    El-Shanshoury, H.; El-Shanshoury, G.; Abaza, A.

    2016-01-01

    Exposure to ionizing radiation is known to have lethal effects in blood cells. It is predicted that an individual may spend days, weeks or even months in a radiation field without becoming alarmed. The study aimed to discuss the evaluation of low dose ionizing radiation (IR) effect on some blood components in animal model. Hematological parameters were determined for 110 animal rats (divided into 8 groups) pre- and post-irradiation. An attempt to explain the blood changes resulting from both ...

  16. Estimation of dose and exposure at sentinel node study

    International Nuclear Information System (INIS)

    Skopljak, A.; Kucukalic-Selimovic, E.; Beslic, N.; Begic, A.; Begovic-Hadzimuratovic, S.; Drazeta, Z.; Beganovic, A.

    2005-01-01

    The purpose of this study was to estimate the dose end exposure in staff involved in sentinel node procedure for breast cancer patients. The Institute of Nuclear Medicine in Sarajevo uses a protocol for lymphoscintigraphy of the sentinel node whereby 13 MBq of 9 9mT c nanocoll are used. In this study, we measured radiation doses and exposure of a nuclear medicine physician and a technologist, as well as a surgeon performing sentinel node lymphoscintigraphy and biopsy. Dose and exposure were calculated using the equation in which we have gamma constant for 9 9mT c. Calculations were made for different times of exposure and distance. In Table 1. we estimated the dose and exposure during sentinel node study. Radiation levels were very low and the most exposed hospital staff performing sentinel node study were nuclear medicine physicians. The doses on the hands of surgeons were negligible 8 hours after exposure.(author)

  17. Evaluation of patient dose in imaging using a cone-beam CT dosimetry by X-ray films for radiotherapeutic dose

    International Nuclear Information System (INIS)

    Yoshida, Yuri; Morita, Yasuhiko; Honda, Eiichi; Tomotake, Yoritoki; Ichikawa, Tetsuo

    2008-01-01

    A limited cone-beam X-ray CT (3DX multi-image micro CT; 3DX-FPD) is widely used in dentistry because it provides a lower cost, smaller size, and higher spatial resolution than a CT for medicine. Our recent research suggested that the patient dose of 3DX-FPD was less than 7/10 of that of CT, and it was several to 10 times more than that of dental or panoramic radiography. The purpose of this study was to evaluate the spatial dose distribution from 3DX-FPD and to estimate the influence of dose by positioning of the region of interest. Dosimetry of the organs and the tissues was performed using an anthropomorphic Alderson Rando phantom and X-ray films for measurement of radiotherapeutic dose. Measurements of dose distribution were performed using a cylinder-type tank of water made of acrylic resin imitating the head and X-ray films. The results are summarized as follows: The dose was higher as the ratio of the air region included in the region of interest increased. The dose distribution was not homogeneous and the dose was highest in the skin region. The dose was higher for several seconds after the beginning of exposure. It was concluded that patient positioning, as well as exposure conditions including the size of the exposure field and tube current, could greatly influence the patient dose in 3DX-FPD. In addition, it is necessary to consider the influence of image quality for the treatment of dental implants. (author)

  18. Patient dose in image guided radiotherapy: Monte Carlo study of the CBCT dose contribution

    Directory of Open Access Journals (Sweden)

    Salvatore Leotta

    2018-02-01

    Full Text Available Image Guided RadioTherapy (IGRT is a technique whose diffusion is growing thanks to the well-recognized gain in accuracy of dose delivery. However, multiple Cone Beam Computed Tomography (CBCT scans add dose to patients, and its contribution has to be assessed and minimized. Aim of our work was to evaluate, through Monte Carlo simulations, organ doses in IGRT due to CBCT and therapeutic MV irradiation in head-neck, thorax and pelvis districts. We developed a Monte Carlo simulation in GAMOS (Geant4-based Architecture for Medicine-Oriented Simulations, reproducing an Elekta Synergy medical linac operating at 6 and 10 MV photon energy, and we set up a scalable anthropomorphic model. After a validation by comparison with the experimental quality indexes, we evaluated the average doses to all organs and tissues belonging to the model for the three cases of irradiated district. Scattered radiation in therapy is larger than that diffused by CBCT by one to two orders of magnitude.

  19. Usefulness evaluation of low-dose for emphysema: Compared with high-resolution CT

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Won Jeong [Dept. of Radiological Technology, Daejeon Health Institute of Technology, Daejeon (Korea, Republic of)

    2016-09-15

    The purpose of this study was to evaluate the usefulness of low-dose CT (LDCT) for emphysema compared with high-resolution CT (HRCT). Measurements of radiation dose and noise were repeated 3 times in same exposure condition which was similar with obtaining HRCT and LDCT images. We analysed reading results of 146 subjects. Six images per participants selected for emphysema grading. Emphysema was graded for all 6 zones on the left and right sides of the lungs by the consensus reading of two chest radiologists using a 4-point scale. Between the HRCT and LDCT images, diagnostic differences and agreements for emphysema were analyzed by McNemar's and unweighted kappa tests, and radiation doses and noise by a Mann-Whitney U-test, using the SPSS 19.0 program. Radiation dose from HRCT was significantly higher than that of LDCT, but the noise was significantly lower in HRCT than in LDCT. Diagnostic agreement for emphysema between HRCT and LDCT images was excellent (k-value=0.88). Emphysema grading scores were not significantly different between HRCT and LDCT images for all six lung zones. Emphysema grading scores from LDCT images were significantly correlated with increased scores on HRCT images (r=0.599, p < 0.001). Considering the tradeoff between radiation dose and image noise, LDCT could be used as the gold standard method instead of HRCT for emphysema detection and grading.

  20. Evaluation of homogeneity and dose conformity in IMRT planning in prostate radiotherapy

    International Nuclear Information System (INIS)

    Lopes, Juliane S.; Leidens, Matheus; Estacio, Daniela R.; Razera, Ricardo A.Z.; Streck, Elaine E.; Silva, Ana M.M. da

    2015-01-01

    The goal of this study was to evaluate the dose distribution homogeneity and conformity of radiation therapy plans of prostate cancer using IMRT. Data from 34 treatment plans of Hospital Sao Lucas of PUCRS, where those plans were executed, were retrospectively analyzed. All of them were done with 6MV X-rays from a linear accelerator CLINAC IX, and the prescription doses varied between 60 and 74 Gy. Analyses showing the homogeneity and conformity indices for the dose distribution of those plans were made. During these analyses, some comparisons with the traditional radiation therapy planning technic, the 3D-CRT, were discussed. The results showed that there is no correlation between the prescribed dose and the homogeneity and conformity indices, indicating that IMRT works very well even for higher doses. Furthermore, a comparison between the results obtained and the recommendations of ICRU 83 was carried out. It has also been observed that the indices were really close to the ideal values. 82.4% of the cases showed a difference below 5% of the ideal value for the index of conformity, and 88.2% showed a difference below 10% for the homogeneity index. Concluding, it is possible to confirm the quality of the analyzed radiation therapy plans of prostate cancer using IMRT. (author)

  1. Dose evaluation for digital X-ray imaging of premature neonates

    International Nuclear Information System (INIS)

    Minkels, T.J.M.; Jeukens, C.R.L.P.N.; Andriessen, P.; Van der Linden, A.N.; Dam, A.J.; Van Straaten, H.L.M.; Cottaar, E.J.E.; Van Pul, C.

    2017-01-01

    X-ray radiography is a commonly used diagnostic method for premature neonates. However, because of higher radiosensitivity and young age, premature neonates are more sensitive to the detrimental effects of ionising radiation. Therefore, it is important to monitor and optimise radiation doses at the neonatal intensive care unit (NICU). The number of X-ray examinations, dose area product (DAP) and effective doses are evaluated for three Dutch NICUs using digital flat panel detectors. Thorax, thorax abdomen and abdomen protocols are included in this study. Median number of examinations is equal to 1 for all three hospitals. Median DAP ranges between 0.05 and 1.02 μGy m2 for different examination types and different weight categories. These examinations result in mean effective doses between 4 ± 4 and 30 ± 10 μSv per examination. Substantial differences in protocols and doses can be observed between hospitals. This emphasises the need for up-to-date reference levels formulated specifically for premature neonates. (authors)

  2. Evaluation of occupational radiation dose in nuclear medicine: radiopharmaceutical administration to scintiscanning exams of myocardial perfusion

    International Nuclear Information System (INIS)

    Komatsu, Cassio V.; Michelin, Charlie A.; Jakubiak, Rosangela R.; Lemes, Alyne O.; Silva, Juliana L.M.

    2013-01-01

    In nuclear medicine, workers directly involved in exams are constantly exposed to ionizing radiation. The procedure for administration of the radiopharmaceutical to the patient is one of the most critical times of exposure. In tests of myocardial perfusion scintigraphy (MPS) administration of radiopharmaceutical repeats the steps of rest and cardiac stress. In this study, we used a Geiger -Mueller detector for measuring occupational radiation doses for during the administration of technetium- 99m - sestamibi in MPS tests. In the evaluation, discriminated the stages of examination and related professional experience time to doses measures at home. It were followed 110 procedures at home (55 conducted by professionals with over 5 years experience and 55 conducted by professionals with less than 1 year of experience) and 55 effort procedures. The results showed that the rest of the procedure time and dose are related to the experience of the worker. More experienced workers were faster (mean: 43 ± 16 vs 67 ± 25 seconds / procedure), and therefore received lower doses (mean 0.57 ± 0.16 versus 0.80 ± 0.24 μSv / procedure), both with statistical significance (p <0.001). In step effort, there were procedures lasting longer (mean: 19 ± 2 minutes / procedure), which resulted in higher doses (mean 3.0 ± 0.6 μSv / procedure)

  3. Evaluation of experimental animal biological state at exposure to low-dose ionizing radiation

    International Nuclear Information System (INIS)

    Rozanov, V.A.; Rejtarova, T.Je.; Chernyikov, G.B.; Timoshevs'ka, Je.V.; Kozozojeva, O.O.

    1997-01-01

    New approaches to quantitative evaluation of ionizing radiation absorbed dose within the low-dose range (up to 400 mGy) according to the degree of the organism biological response was developed. The purpose of the stage of the work published in Communication 1 is to evaluate the shifts in the animal behaviour and cellular composition of the blood at irradiation by the dose of 100,200 and 400 mGy. Distinct dose dependence of behaviour reactions and hematological indices within the dose range of 100-400 mGy was not noted

  4. Studies on the chronic effect of lower dose level irradiation

    International Nuclear Information System (INIS)

    Yun, T.G.; Yun, E.S.; Chung, I.Y.; Yun, M.S.; Chae, H.S.; Lee, J.Y.

    1982-01-01

    This experiment was carried out to evaluate the chronic hazard of Co-60 low dose radiation on ICR mice. There is now considerable evidence from human studies that age, both at exposure to radiation and at observation for risk, can be major determinant of radiation induced cancer risk. For this reason, ICR mice at different ages such as below were exposed to 60m rads/week, 500m rads/week and 60 rads/biweek whole body Co-60 radiation at a dose rate of 3.6 rads/min. ICR mice were irradiated during pregnant period, from 1st week to 3rd week, from 3rd week to 52nd week, from 6th week to 52nd week, and from 22nd week to 52nd week after the birth. All experimental mice were autopsied immediately after being sacrificed at 52nd week. All major organs were examined grossly and weighed. After fixation histo-pathological preparations were made for microscopical study. Blood cells W.B.C., R.B.C., Hb-from eye's vein were counted by hemocytometer and hemometer. (Author)

  5. Evaluation of heterogeneity dose distributions for Stereotactic Radiotherapy (SRT: comparison of commercially available Monte Carlo dose calculation with other algorithms

    Directory of Open Access Journals (Sweden)

    Takahashi Wataru

    2012-02-01

    Full Text Available Abstract Background The purpose of this study was to compare dose distributions from three different algorithms with the x-ray Voxel Monte Carlo (XVMC calculations, in actual computed tomography (CT scans for use in stereotactic radiotherapy (SRT of small lung cancers. Methods Slow CT scan of 20 patients was performed and the internal target volume (ITV was delineated on Pinnacle3. All plans were first calculated with a scatter homogeneous mode (SHM which is compatible with Clarkson algorithm using Pinnacle3 treatment planning system (TPS. The planned dose was 48 Gy in 4 fractions. In a second step, the CT images, structures and beam data were exported to other treatment planning systems (TPSs. Collapsed cone convolution (CCC from Pinnacle3, superposition (SP from XiO, and XVMC from Monaco were used for recalculating. The dose distributions and the Dose Volume Histograms (DVHs were compared with each other. Results The phantom test revealed that all algorithms could reproduce the measured data within 1% except for the SHM with inhomogeneous phantom. For the patient study, the SHM greatly overestimated the isocenter (IC doses and the minimal dose received by 95% of the PTV (PTV95 compared to XVMC. The differences in mean doses were 2.96 Gy (6.17% for IC and 5.02 Gy (11.18% for PTV95. The DVH's and dose distributions with CCC and SP were in agreement with those obtained by XVMC. The average differences in IC doses between CCC and XVMC, and SP and XVMC were -1.14% (p = 0.17, and -2.67% (p = 0.0036, respectively. Conclusions Our work clearly confirms that the actual practice of relying solely on a Clarkson algorithm may be inappropriate for SRT planning. Meanwhile, CCC and SP were close to XVMC simulations and actual dose distributions obtained in lung SRT.

  6. SU-F-T-122: 4Dand 5D Proton Dose Evaluation with Monte Carlo

    Energy Technology Data Exchange (ETDEWEB)

    Titt, U; Mirkovic, D; Yepes, P; Liu, A; Peeler, C; Randenyia, S; Mohan, R [UT MD Anderson Cancer Center, Houston, TX (United States)

    2016-06-15

    Purpose: We evaluated uncertainties in therapeutic proton doses of a lung treatment, taking into account intra-fractional geometry changes, such as breathing, and inter-fractional changes, such as tumor shrinkage and weight loss. Methods: A Monte Carlo study was performed using four dimensional CT image sets (4DCTs) and weekly repeat imaging (5DCTs) to compute fixed RBE (1.1) and variable RBE weighted dose in an actual lung treatment geometry. The MC2 Monte Carlo system was employed to simulate proton energy deposition and LET distributions according to a thoracic cancer treatment plan developed with a 3D-CT in a commercial treatment planning system, as well as in each of the phases of 4DCT sets which were recorded weekly throughout the course of the treatment. A cumulative dose distribution in relevant structures was computed and compared to the predictions of the treatment planning system. Results: Using the Monte Carlo method, dose deposition estimates with the lowest possible uncertainties were produced. Comparison with treatment planning predictions indicates that significant uncertainties may be associated with therapeutic lung dose prediction from treatment planning systems, depending on the magnitude of inter- and intra-fractional geometry changes. Conclusion: As this is just a case study, a more systematic investigation accounting for a cohort of patients is warranted; however, this is less practical because Monte Carlo simulations of such cases require enormous computational resources. Hence our study and any future case studies may serve as validation/benchmarking data for faster dose prediction engines, such as the track repeating algorithm, FDC.

  7. Studies of absorbed dose determinations and spatial dose distributions for high energy proton beams

    International Nuclear Information System (INIS)

    Hiraoka, Takeshi

    1982-01-01

    Absolute dose determinations were made with three types of ionization chamber and a Faraday cup. Methane based tissue equivalent (TE) gas, nitrogen, carbon dioxide, air were used as an ionizing gas with flow rate of 10 ml per minute. Measurements were made at the entrance position of unmodulated beams and for a beam of a spread out Bragg peak at a depth of 17.3 mm in water. For both positions, the mean value of dose determined by the ionization chambers was 0.993 +- 0.014 cGy for which the value of TE gas was taken as unity. The agreement between the doses estimated by the ionization chambers and the Faraday cup was within 5%. Total uncertainty estimated in the ionization chamber and the Faraday cup determinations is 6 and 4%, respectively. Common sources of error in calculating the dose from ionization chamber measurements are depend on the factors of ion recombination, W value, and mass stopping power ratio. These factors were studied by both experimentally and theoretically. The observed values for the factors show a good agreement to the predicted one. Proton beam dosimetry intercomparison between Japan and the United States was held. Good agreement was obtained with standard deviation of 1.6%. The value of the TE calorimeter is close to the mean value of all. In the proton spot scanning system, lateral dose distributions at any depth for one spot beam can be simulated by the Gaussian distribution. From the Gaussian distributions and the central axis depth doses for one spot beam, it is easy to calculate isodose distributions in the desired field by superposition of dose distribution for one spot beam. Calculated and observed isodose curves were agreed within 1 mm at any dose levels. (J.P.N.)

  8. Preparation and the Biopharmaceutical Evaluation for the Metered Dose Transdermal Spray of Dexketoprofen

    Science.gov (United States)

    Luo, Huafei; Zhu, Zhuangzhi; Wu, Yubo; Luo, Jing; Wang, Hao

    2014-01-01

    The objective of the present work was to develop a metered dose transdermal spray (MDTS) formulation for transdermal delivery of dexketoprofen (DE). DE release from a series of formulations was assessed in vitro. Various qualitative and quantitative parameters like spray pattern, pump seal efficiency test, average weight per metered dose, and dose uniformity were evaluated. The optimized formulation with good skin permeation and an appropriate drug concentration and permeation enhancer (PE) content was developed incorporating 7% (w/w, %) DE, 7% (v/v, %) isopropyl myristate (IPM), and 93% (v/v, %) ethanol. In vivo pharmacokinetic study indicated that the optimized formulation showed a more sustainable plasma-concentration profile compared with the Fenli group. The antiinflammatory effect of DE MDTS was evaluated by experiments involving egg-albumin-induced paw edema in rats and xylene-induced ear swelling in mice. Acetic acid-induced abdominal constriction was used to evaluate the anti-nociceptive actions of DE MDTS. Pharmacodynamic studies indicated that the DE MDTS has good anti-inflammatory and anti-nociceptive activities. Besides, skin irritation studies were performed using rat as an animal model. The results obtained show that the MDTS can be a promising and innovative therapeutic system used in transdermal drug delivery for DE. PMID:24660066

  9. Preparation and the Biopharmaceutical Evaluation for the Metered Dose Transdermal Spray of Dexketoprofen

    Directory of Open Access Journals (Sweden)

    Wangding Lu

    2014-01-01

    Full Text Available The objective of the present work was to develop a metered dose transdermal spray (MDTS formulation for transdermal delivery of dexketoprofen (DE. DE release from a series of formulations was assessed in vitro. Various qualitative and quantitative parameters like spray pattern, pump seal efficiency test, average weight per metered dose, and dose uniformity were evaluated. The optimized formulation with good skin permeation and an appropriate drug concentration and permeation enhancer (PE content was developed incorporating 7% (w/w, % DE, 7% (v/v, % isopropyl myristate (IPM, and 93% (v/v, % ethanol. In vivo pharmacokinetic study indicated that the optimized formulation showed a more sustainable plasma-concentration profile compared with the Fenli group. The antiinflammatory effect of DE MDTS was evaluated by experiments involving egg-albumin-induced paw edema in rats and xylene-induced ear swelling in mice. Acetic acid-induced abdominal constriction was used to evaluate the anti-nociceptive actions of DE MDTS. Pharmacodynamic studies indicated that the DE MDTS has good anti-inflammatory and anti-nociceptive activities. Besides, skin irritation studies were performed using rat as an animal model. The results obtained show that the MDTS can be a promising and innovative therapeutic system used in transdermal drug delivery for DE.

  10. Percentage depth dose evaluation in heterogeneous media using thermoluminescent dosimetry

    Science.gov (United States)

    da Rosa, L.A.R.; Campos, L.T.; Alves, V.G.L.; Batista, D.V.S.; Facure, A.

    2010-01-01

    The purpose of this study is to investigate the influence of lung heterogeneity inside a soft tissue phantom on percentage depth dose (PDD). PDD curves were obtained experimentally using LiF:Mg,Ti (TLD‐100) thermoluminescent detectors and applying Eclipse treatment planning system algorithms Batho, modified Batho (M‐Batho or BMod), equivalent TAR (E‐TAR or EQTAR), and anisotropic analytical algorithm (AAA) for a 15 MV photon beam and field sizes of 1×1,2×2,5×5, and 10×10cm2. Monte Carlo simulations were performed using the DOSRZnrc user code of EGSnrc. The experimental results agree with Monte Carlo simulations for all irradiation field sizes. Comparisons with Monte Carlo calculations show that the AAA algorithm provides the best simulations of PDD curves for all field sizes investigated. However, even this algorithm cannot accurately predict PDD values in the lung for field sizes of 1×1 and 2×2cm2. An overdosage in the lung of about 40% and 20% is calculated by the AAA algorithm close to the interface soft tissue/lung for 1×1 and 2×2cm2 field sizes, respectively. It was demonstrated that differences of 100% between Monte Carlo results and the algorithms Batho, modified Batho, and equivalent TAR responses may exist inside the lung region for the 1×1cm2 field. PACS number: 87.55.kd

  11. Study of genomic instability induced by low dose ionizing radiation

    International Nuclear Information System (INIS)

    Seoane, A.; Crudeli, C.; Dulout, F.

    2006-01-01

    The crews of commercial flights and services staff of radiology and radiotherapy from hospitals are exposed to low doses of ionizing radiation. Genomic instability includes those adverse effects observed in cells, several generations after the exposure occurred. The purpose of this study was to analyze the occurrence of genomic instability by very low doses of ionizing radiation [es

  12. Evaluation of dose-volume metrics for microbeam radiation therapy dose distributions in head phantoms of various sizes using Monte Carlo simulations

    Science.gov (United States)

    Anderson, Danielle; Siegbahn, E. Albert; Fallone, B. Gino; Serduc, Raphael; Warkentin, Brad

    2012-05-01

    This work evaluates four dose-volume metrics applied to microbeam radiation therapy (MRT) using simulated dosimetric data as input. We seek to improve upon the most frequently used MRT metric, the peak-to-valley dose ratio (PVDR), by analyzing MRT dose distributions from a more volumetric perspective. Monte Carlo simulations were used to calculate dose distributions in three cubic head phantoms: a 2 cm mouse head, an 8 cm cat head and a 16 cm dog head. The dose distribution was calculated for a 4 × 4 mm2 microbeam array in each phantom, as well as a 16 × 16 mm2 array in the 8 cm cat head, and a 32 × 32 mm2 array in the 16 cm dog head. Microbeam widths of 25, 50 and 75 µm and center-to-center spacings of 100, 200 and 400 µm were considered. The metrics calculated for each simulation were the conventional PVDR, the peak-to-mean valley dose ratio (PMVDR), the mean dose and the percentage volume below a threshold dose. The PVDR ranged between 3 and 230 for the 2 cm mouse phantom, and between 2 and 186 for the 16 cm dog phantom depending on geometry. The corresponding ranges for the PMVDR were much smaller, being 2-49 (mouse) and 2-46 (dog), and showed a slightly weaker dependence on phantom size and array size. The ratio of the PMVDR to the PVDR varied from 0.21 to 0.79 for the different collimation configurations, indicating a difference between the geometric dependence on outcome that would be predicted by these two metrics. For unidirectional irradiation, the mean lesion dose was 102%, 79% and 42% of the mean skin dose for the 2 cm mouse, 8 cm cat and 16 cm dog head phantoms, respectively. However, the mean lesion dose recovered to 83% of the mean skin dose in the 16 cm dog phantom in intersecting cross-firing regions. The percentage volume below a 10% dose threshold was highly dependent on geometry, with ranges for the different collimation configurations of 2-87% and 33-96% for the 2 cm mouse and 16 cm dog heads, respectively. The results of this study

  13. Evaluation of dose-volume metrics for microbeam radiation therapy dose distributions in head phantoms of various sizes using Monte Carlo simulations

    International Nuclear Information System (INIS)

    Anderson, Danielle; Fallone, B Gino; Warkentin, Brad; Siegbahn, E Albert; Serduc, Raphael

    2012-01-01

    This work evaluates four dose-volume metrics applied to microbeam radiation therapy (MRT) using simulated dosimetric data as input. We seek to improve upon the most frequently used MRT metric, the peak-to-valley dose ratio (PVDR), by analyzing MRT dose distributions from a more volumetric perspective. Monte Carlo simulations were used to calculate dose distributions in three cubic head phantoms: a 2 cm mouse head, an 8 cm cat head and a 16 cm dog head. The dose distribution was calculated for a 4 × 4 mm 2 microbeam array in each phantom, as well as a 16 × 16 mm 2 array in the 8 cm cat head, and a 32 × 32 mm 2 array in the 16 cm dog head. Microbeam widths of 25, 50 and 75 µm and center-to-center spacings of 100, 200 and 400 µm were considered. The metrics calculated for each simulation were the conventional PVDR, the peak-to-mean valley dose ratio (PMVDR), the mean dose and the percentage volume below a threshold dose. The PVDR ranged between 3 and 230 for the 2 cm mouse phantom, and between 2 and 186 for the 16 cm dog phantom depending on geometry. The corresponding ranges for the PMVDR were much smaller, being 2–49 (mouse) and 2–46 (dog), and showed a slightly weaker dependence on phantom size and array size. The ratio of the PMVDR to the PVDR varied from 0.21 to 0.79 for the different collimation configurations, indicating a difference between the geometric dependence on outcome that would be predicted by these two metrics. For unidirectional irradiation, the mean lesion dose was 102%, 79% and 42% of the mean skin dose for the 2 cm mouse, 8 cm cat and 16 cm dog head phantoms, respectively. However, the mean lesion dose recovered to 83% of the mean skin dose in the 16 cm dog phantom in intersecting cross-firing regions. The percentage volume below a 10% dose threshold was highly dependent on geometry, with ranges for the different collimation configurations of 2–87% and 33–96% for the 2 cm mouse and 16 cm dog heads, respectively. The results of this

  14. An open-label, multicenter, flexible dose study to evaluate the efficacy and safety of Viagra (sildenafil citrate) in Korean men with erectile dysfunction and arterial hypertension who are taking antihypertensive agents.

    Science.gov (United States)

    Park, Hyun Jun; Park, Nam Cheol; Shim, Hong Bang; Park, Jong Kwan; Lee, Sung Won; Park, Kwangsung; Kim, Sae Woong; Moon, Ki Hak; Lee, Dong Hyeon; Yoon, Sang Jin

    2008-10-01

    Erectile dysfunction (ED) is common among men taking antihypertensive agents to control blood pressure. We evaluated the efficacy and safety of sildenafil citrate in men with ED taking antihypertensive agents. A total of 198 male subjects, aged 20 years and older were enrolled. This study was conducted for 10 weeks as an open-label, multicenter and flexible dose trial with a 2-week screening period and an 8-week treatment phase. Subjects were asked to complete Event Log Worksheets, as well as the International Index of Erectile Function (IIEF) and the Global Efficacy Assessment Questions (GEAQ) questionnaires during the study period. The average age among the 167 subjects who completed the study was 55.8 (31.7 to 77.1). The scores for questions 3 and 4 of IIEF improved from 2.3 and 1.8 at baseline to 3.7 and 3.4 at week 4 and 3.8 and 3.4 at week 8, respectively. There were 86.3% of the patients reported improved erectile function at week 8; 88.3% of the patients reported improved ability to achieve sexual intercourse at week 8. There were no significant differences observed in the responses to questions 3 and 4 of IIEF and GEAQ by the number of antihypertensive agents taken. The adverse events were facial flushing (20.1%), headache (11.7%), palpitation (5.0%), rhinitis (2.8%), URI (2.8%), dizziness (2.2%), dyspnea (2.2%), and nausea (1.7%). Sildenafil citrate is an effective treatment for ED; it is safe and well tolerated by patients with ED taking multiple antihypertensive agents for arterial hypertension.

  15. Evaluation of radiological protection and dose of skin entrance in paediatric dentistry examinations

    International Nuclear Information System (INIS)

    Khoury, Helen Jamil; Silveira, Marcia Maria Fonseca da; Couto, Geraldo Bosco Lindoso; Brasileiro, Izabela Vanderley

    2005-01-01

    In this work the radiological protection conditions and dose at the entrance of pediatric patients undergoing dental intraoral radiographs were evaluated. The study was conducted in two clinics of the dentistry course at the Federal University of Pernambuco, Recife, PB, Brazil, equipped with conventional X-ray apparatus, with 60 and 70 kV. 254 exams of 113 patients between the ages of 3 to 12 years were evaluated. The skin entrance dose was estimated using TLD-100 thermoluminescent dosemeters. During the examination were also recorded information regarding the time of exposure, radiographic technique used, use of thyroid protectors and lead apron, angle and distance of the cone Locator to the patient's skin. The results showed that the input skin doses ranged from 0.3 mGy to 10mGy. The lead apron was used in 71% of exams while the thyroid shield was only used in 58% of the exams. The exposure times ranged from 0,5s to 1,5s. From the results it can be concluded that the radiological procedures are not optimized and that in some cases the patient dose is high.

  16. Evaluation of intensity modulated radiation therapy dose painting for localized prostate cancer using 68Ga-HBED-CC PSMA-PET/CT: A planning study based on histopathology reference.

    Science.gov (United States)

    Zamboglou, Constantinos; Sachpazidis, Ilias; Koubar, Khodor; Drendel, Vanessa; Wiehle, Rolf; Kirste, Simon; Mix, Michael; Schiller, Florian; Mavroidis, Panayiotis; Meyer, Philipp T; Werner, Martin; Grosu, Anca L; Baltas, Dimos

    2017-06-01

    To demonstrate the feasibility and to evaluate the tumour control probability (TCP) and normal tissue complication probability (NTCP) of IMRT dose painting using 68 Ga-HBED-CC PSMA PET/CT for target delineation in prostate cancer (PCa). 10 patients had PSMA PET/CT scans prior to prostatectomy. GTV-PET was generated on the basis of an intraprostatic SUVmax of 30%. Two IMRT plans were generated for each patient: Plan 77 which consisted of whole-prostate IMRT to 77Gy, and Plan 95 which consisted of whole-prostate IMRT to 77Gy and a simultaneous integrated boost to the GTV-PET up to 95Gy (35 fractions). The feasibility of these plans was judged by their ability to adhere to the FLAME trial protocol. TCP-histo/-PET were calculated on co-registered histology (GTV-histo) and GTV-PET, respectively. NTCPs for rectum and bladder were calculated. All plans reached prescription doses whilst adhering to dose constraints. In Plan 77 and Plan 95 mean doses in GTV-histo were 75.8±0.3Gy and 96.9±1Gy, respectively. Average TCP-histo values for Plan 77 and Plan 95 were 70% (range: 15-97%), and 96% (range: 78-100%, pPET values for Plan 77 and Plan 95 were 55% (range: 27-82%), and 100% (range: 99-100%, pPET and TCP-histo in Plan 95 (p=0.25). There were no significant differences in rectal (p=0.563) and bladder (p=0.3) NTCPs. IMRT dose painting using PSMA PET/CT was technically feasible and resulted in significantly higher TCPs without higher NTCPs. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. SU-F-T-474: Evaluation of Dose Perturbation, Temperature and Sensitivity Variation With Accumulated Dose of MOSFET Detector

    Energy Technology Data Exchange (ETDEWEB)

    Ganesan, B; Prakasarao, A; Singaravelu, G [Anna University, Chennai, TamilNadu (India); Palraj, T; Rai, R [Dr. Rai Memorial Cancer Institute, Chennai, TamilNadu (India)

    2016-06-15

    Purpose: The use of mega voltage gamma and x-ray sources with their skin sparring qualities in radiation therapy has been a boon in relieving patient discomfort and allowing high tumor doses to be given with fewer restrictions due to radiation effects in the skin. However, high doses given to deep tumors may require careful consideration of dose distribution in the buildup region in order to avoid irreparable damage to the skin. Methods: To measure the perturbation of MOSFET detector in Co60,6MV and 15MV the detector was placed on the surface of the phantom covered with the brass build up cap. To measure the effect of temperature the MOSFET detector was kept on the surface of hot water polythene container and the radiation was delivere. In order to measure the sensitivity variation with accumulated dose Measurements were taken by delivering the dose of 200 cGy to MOSFET until the MOSFET absorbed dose comes to 20,000 cGy Results: the Measurement was performed by positioning the bare MOSFET and MOSFET with brass build up cap on the top surface of the solid water phantom for various field sizes in order to find whether there is any attenuation caused in the dose distribution. The response of MOSFET was monitored for temperature ranging from 42 degree C to 22 degree C. The integrated dose dependence of MOSFET dosimeter sensitivity over different energy is not well characterized. This work investigates the dual-bias MOSFET dosimeter sensitivity response to 6 MV and 15 MV beams. Conclusion: From this study it is observed that unlike diode, bare MOSFET does not perturb the radiation field.. It is observed that the build-up influences the temperature dependency of MOSFET and causes some uncertainty in the readings. In the case of sensitivity variation with accumulated dose MOSFET showed higher sensitivity with dose accumulation for both the energies.

  18. SU-F-T-474: Evaluation of Dose Perturbation, Temperature and Sensitivity Variation With Accumulated Dose of MOSFET Detector

    International Nuclear Information System (INIS)

    Ganesan, B; Prakasarao, A; Singaravelu, G; Palraj, T; Rai, R

    2016-01-01

    Purpose: The use of mega voltage gamma and x-ray sources with their skin sparring qualities in radiation therapy has been a boon in relieving patient discomfort and allowing high tumor doses to be given with fewer restrictions due to radiation effects in the skin. However, high doses given to deep tumors may require careful consideration of dose distribution in the buildup region in order to avoid irreparable damage to the skin. Methods: To measure the perturbation of MOSFET detector in Co60,6MV and 15MV the detector was placed on the surface of the phantom covered with the brass build up cap. To measure the effect of temperature the MOSFET detector was kept on the surface of hot water polythene container and the radiation was delivere. In order to measure the sensitivity variation with accumulated dose Measurements were taken by delivering the dose of 200 cGy to MOSFET until the MOSFET absorbed dose comes to 20,000 cGy Results: the Measurement was performed by positioning the bare MOSFET and MOSFET with brass build up cap on the top surface of the solid water phantom for various field sizes in order to find whether there is any attenuation caused in the dose distribution. The response of MOSFET was monitored for temperature ranging from 42 degree C to 22 degree C. The integrated dose dependence of MOSFET dosimeter sensitivity over different energy is not well characterized. This work investigates the dual-bias MOSFET dosimeter sensitivity response to 6 MV and 15 MV beams. Conclusion: From this study it is observed that unlike diode, bare MOSFET does not perturb the radiation field.. It is observed that the build-up influences the temperature dependency of MOSFET and causes some uncertainty in the readings. In the case of sensitivity variation with accumulated dose MOSFET showed higher sensitivity with dose accumulation for both the energies.

  19. Evaluation of the dose distribution for prostate implants using various 125I and 103Pd sources

    International Nuclear Information System (INIS)

    Meigooni, Ali S.; Luerman, Christine M.; Sowards, Keith T.

    2009-01-01

    Recently, several different models of 125 I and 103 Pd brachytherapy sources have been introduced in order to meet the increasing demand for prostate seed implants. These sources have different internal structures; hence, their TG-43 dosimetric parameters are not the same. In this study, the effects of the dosimetric differences among the sources on their clinical applications were evaluated. The quantitative and qualitative evaluations were performed by comparisons of dose distributions and dose volume histograms of prostate implants calculated for various designs of 125 I and 103 Pd sources. These comparisons were made for an identical implant scheme with the same number of seeds for each source. The results were compared with the Amersham model 6711 seed for 125 I and the Theragenics model 200 seed for 103 Pd using the same implant scheme.

  20. Effective dose evaluation of NORM-added consumer products using Monte Carlo simulations and the ICRP computational human phantoms.

    Science.gov (United States)

    Lee, Hyun Cheol; Yoo, Do Hyeon; Testa, Mauro; Shin, Wook-Geun; Choi, Hyun Joon; Ha, Wi-Ho; Yoo, Jaeryong; Yoon, Seokwon; Min, Chul Hee

    2016-04-01

    The aim of this study is to evaluate the potential hazard of naturally occurring radioactive material (NORM) added consumer products. Using the Monte Carlo method, the radioactive products were simulated with ICRP reference phantom and the organ doses were calculated with the usage scenario. Finally, the annual effective doses were evaluated as lower than the public dose limit of 1mSv y(-1) for 44 products. It was demonstrated that NORM-added consumer products could be quantitatively assessed for the safety regulation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Patient radiation exposure dose evaluation of whole spine scanography due to exposure direction

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jung Su; Seo, Deok Nam [Dept. of Bio-convergence Engineering, Graduate School of Korea University, Seoul (Korea, Republic of); Kwon, Soon Mu [Dept. of Radiologic Technology, Daegu Health College, Daegu (Korea, Republic of); Kim, Jung Min [Dept. of Radiological Science, Korea University, Seoul (Korea, Republic of)

    2015-04-15

    Whole spine scanography (WSS) is a radiological examination that exposes the whole body of the individual being examined to x-ray radiation. WSS is often repeated during the treatment period, which results in a much greater radiation exposure than that in routine x-ray examinations. The aims of the current study were to evaluate the patient dose of WSS using computer simulation, image magnification and angulation of phantom image using different patient position. We evaluated the effective dose(ED) of 23 consecutive patients (M : F = 13:10) who underwent WSS, based on the automatic image pasting method for multiple exposure digital radiography. The Anterior-Posterior position(AP) and Posterior-Anterior position( PA) projection EDs were evaluated based on the PC based Monte Carlo simulation. We measured spine transverse process distance and angulation using DICOM measurement. For all patient, the average ED was 0.069 mSv for AP position and 0.0361 mSv for PA position. AP position calculated double exposure then PA position. For male patient, the average ED was 0.089 mSv(AP) and 0.050 mSv(PA). For female patient, the average ED was 0.0431 mSv(AP) and 0.026 mSv(PA). The transverse process of PA spine image measured 5% higher than AP but angulation of transverse process was no significant differences. In clinical practice, just by change the patient position was conformed to reduce the ED of patient. Therefore we need to redefine of protocol for digital radiography such as WSS, whole spine scanography, effective dose, patient exposure dose, exposure direction, protocol optimization.

  2. Low dose evaluation of the antiandrogen flutamide following a Mode of Action approach

    International Nuclear Information System (INIS)

    Sarrabay, A.; Hilmi, C.; Tinwell, H.; Schorsch, F.; Pallardy, M.; Bars, R.; Rouquié, D.

    2015-01-01

    ABSTRACT: The dose–response characterization of endocrine mediated toxicity is an on-going debate which is controversial when exploring the nature of the dose–response curve and the effect at the low-end of the curve. To contribute to this debate we have assessed the effects of a wide range of dose levels of the antiandrogen flutamide (FLU) on 7-week male Wistar rats. FLU was administered by oral gavage at doses of 0, 0.001, 0.01, 0.1, 1 and 10 mg/kg/day for 28 days. To evaluate the reproducibility, the study was performed 3 times. The molecular initiating event (MIE; AR antagonism), the key events (LH increase, Leydig cell proliferation and hyperplasia increases) and associated events involved in the mode of action (MOA) of FLU induced testicular toxicity were characterized to address the dose response concordance. Results showed no effects at low doses (< 0.1 mg/kg/day) for the different key events studied. The histopathological changes (Leydig cell hyperplasia) observed at 1 and 10 mg/kg/day were associated with an increase in steroidogenesis gene expression in the testis from 1 mg/kg/day, as well as an increase in testosterone blood level at 10 mg/kg/day. Each key event dose–response was in good concordance with the MOA of FLU on the testis. From the available results, only monotonic dose–response curves were observed for the MIE, the key events, associated events and in effects observed in other sex related tissues. All the results, so far, show that the reference endocrine disruptor FLU induces threshold effects in a standard 28-day toxicity study on adult male rats. - Highlights: • Dose–response characterization of endocrine mediated toxicity is an on-going debate. • A wide range of dose levels of flutamide was evaluated on young adult male rats. • Flutamide induces threshold effects using on standard and molecular tools.

  3. Low dose evaluation of the antiandrogen flutamide following a Mode of Action approach

    Energy Technology Data Exchange (ETDEWEB)

    Sarrabay, A. [INSERM, Université Paris-Sud, Faculté de Pharmacie, Châtenay-Malabry (France); UniverSud, INSERM, UMR-996 “Inflammation, Chemokines and Immunopathology”, Châtenay-Malabry (France); Bayer SAS, 16, rue Jean Marie Leclair, 69009 Lyon (France); Hilmi, C.; Tinwell, H.; Schorsch, F. [Bayer SAS, 16, rue Jean Marie Leclair, 69009 Lyon (France); Pallardy, M. [INSERM, Université Paris-Sud, Faculté de Pharmacie, Châtenay-Malabry (France); UniverSud, INSERM, UMR-996 “Inflammation, Chemokines and Immunopathology”, Châtenay-Malabry (France); Bars, R. [Bayer SAS, 16, rue Jean Marie Leclair, 69009 Lyon (France); Rouquié, D., E-mail: david.rouquie@bayer.com [Bayer SAS, 16, rue Jean Marie Leclair, 69009 Lyon (France)

    2015-12-15

    ABSTRACT: The dose–response characterization of endocrine mediated toxicity is an on-going debate which is controversial when exploring the nature of the dose–response curve and the effect at the low-end of the curve. To contribute to this debate we have assessed the effects of a wide range of dose levels of the antiandrogen flutamide (FLU) on 7-week male Wistar rats. FLU was administered by oral gavage at doses of 0, 0.001, 0.01, 0.1, 1 and 10 mg/kg/day for 28 days. To evaluate the reproducibility, the study was performed 3 times. The molecular initiating event (MIE; AR antagonism), the key events (LH increase, Leydig cell proliferation and hyperplasia increases) and associated events involved in the mode of action (MOA) of FLU induced testicular toxicity were characterized to address the dose response concordance. Results showed no effects at low doses (< 0.1 mg/kg/day) for the different key events studied. The histopathological changes (Leydig cell hyperplasia) observed at 1 and 10 mg/kg/day were associated with an increase in steroidogenesis gene expression in the testis from 1 mg/kg/day, as well as an increase in testosterone blood level at 10 mg/kg/day. Each key event dose–response was in good concordance with the MOA of FLU on the testis. From the available results, only monotonic dose–response curves were observed for the MIE, the key events, associated events and in effects observed in other sex related tissues. All the results, so far, show that the reference endocrine disruptor FLU induces threshold effects in a standard 28-day toxicity study on adult male rats. - Highlights: • Dose–response characterization of endocrine mediated toxicity is an on-going debate. • A wide range of dose levels of flutamide was evaluated on young adult male rats. • Flutamide induces threshold effects using on standard and molecular tools.

  4. Comparison of dose evaluation index by pencil beam convolution and anisotropic analytical algorithm in stereotactic radiotherapy for lung cancer

    International Nuclear Information System (INIS)

    Tachibana, Masayuki; Noguchi, Yoshitaka; Fukunaga, Jyunichi; Hirano, Naomi; Yoshidome, Satoshi; Hirose, Takaaki

    2009-01-01

    We previously studied dose distributions of stereotactic radiotherapy (SRT) for lung cancer. Our aim is to compare in combination pencil beam convolution with the inhomogeneity correction algorithm of Batho power low [PBC (BPL)] to the anisotropic analytical algorithm (AAA) by using the dose evaluation indexes. There were significant differences in D95, planning target volume (PTV) mean dose, homogeneity index, and conformity index, V10, and V5. The dose distributions inside the PTV calculated by PBC (BPL) were more uniform than those of AAA. There were no significant differences in V20 and mean dose of total lung. There was no large difference for the whole lung. However, the surrounding high-dose region of PTV became smaller in AAA. The difference in dose evaluation indexes extended between PBC (BPL) and AAA that as many as low CT value of lung. When the dose calculation algorithm is changed, it is necessary to consider difference dose distributions compared with those of established practice. (author)

  5. Evaluation of patients radiation dose from computed tomography during lower peripheral angiography procedure

    International Nuclear Information System (INIS)

    Khlafallah, Leena Ahmed Ali

    2015-09-01

    The purpose of this study was to evaluate patient radiation doses in lower peripheral angiography CT examinations in Sudan. Survey was conducted in four major hospitals which almost carry out lower peripheral angiography procedures in Sudan at the time of study. All hospitals were equipped with 64 slices multi detectors CT from Toshiba (Japan). The total number of patients was 74. Information on patient's genders and ages, exposure technique factors and radiation dose were collected. The procedures performed in multi phases, up to five phases covering part of the abdomen region, which can make patients exposure reasonably high. CTDI values in the different phases ranged between (13-30) mGy. The total DLP in the four hospitals were 6888.75, 5065.05, 6608.88 and 5754.9 mGy.cm. This study provided first survey for patient dose during lower peripheral angiography procedures in Sudan. Taking into account that the CT machines were similar: the variation between patient's DLP and CTDI values in the different hospitals indicated the need of optimization of radiation protection. Staff training and awareness on factors affecting patient dose are essential.(Author)

  6. Evaluation of ovary dose for woman of childbearing age woman with breast cancer in tomotherapy

    International Nuclear Information System (INIS)

    Lee, Soo Hyeong; Park, Soo Yeon; Choi, Ji Min; Park, Ju Young; Kim, Jong Suk

    2014-01-01

    The aim of this study is to evaluate unwanted scattered dose to ovary by scattering and leakage generated from treatment fields of Tomotherapy for childbearing woman with breast cancer. The radiation treatments plans for left breast cancer were established using Tomotherapy planning system (Tomotherapy, Inc, USA). They were generated by using helical and direct Tomotherapy methods for comparison. The CT images for the planning were scanned with 2.5 mm slice thickness using anthropomorphic phantom (Alderson-Rando phantom, The Phantom Laboratory, USA). The measurement points for the ovary dose were determined at the points laterally 30 cm apart from mid-point of treatment field of the pelvis. The measurements were repeated five times and averaged using glass dosimeters (1.5 mm diameter and 12 mm of length) equipped with low-energy correction filter. The measures dose values were also converted to Organ Equivalent Dose (OED) by the linear exponential dose-response model. Scattered doses of ovary which were measured based on two methods of Tomo helical and Tomo direct showed average of 64.94±0.84 mGy and 37.64±1.20 mGy in left ovary part and average of 64.38±1.85 mGy and 32.96±1.11 mGy in right ovary part. This showed when executing Tomotherapy, measured scattered dose of Tomo Helical method which has relatively greater monitor units (MUs) and longer irradiation time are approximately 1.8 times higher than Tomo direct method. Scattered dose of left and right ovary of childbearing women is lower than ICRP recommended does which is not seriously worried level against the infertility and secondary cancer occurrence. However, as breast cancer occurrence ages become younger in the future and radiation therapy using high-precision image guidance equipment like Tomotherapy is developed, clinical follow-up studies about the ovary dose of childbearing women patients would be more required

  7. Evaluation of ovary dose for woman of childbearing age woman with breast cancer in tomotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Soo Hyeong; Park, Soo Yeon; Choi, Ji Min; Park, Ju Young; Kim, Jong Suk [Dept. of Radiation Oncology, Samsung Medical Center, Seoul (Korea, Republic of)

    2014-12-15

    The aim of this study is to evaluate unwanted scattered dose to ovary by scattering and leakage generated from treatment fields of Tomotherapy for childbearing woman with breast cancer. The radiation treatments plans for left breast cancer were established using Tomotherapy planning system (Tomotherapy, Inc, USA). They were generated by using helical and direct Tomotherapy methods for comparison. The CT images for the planning were scanned with 2.5 mm slice thickness using anthropomorphic phantom (Alderson-Rando phantom, The Phantom Laboratory, USA). The measurement points for the ovary dose were determined at the points laterally 30 cm apart from mid-point of treatment field of the pelvis. The measurements were repeated five times and averaged using glass dosimeters (1.5 mm diameter and 12 mm of length) equipped with low-energy correction filter. The measures dose values were also converted to Organ Equivalent Dose (OED) by the linear exponential dose-response model. Scattered doses of ovary which were measured based on two methods of Tomo helical and Tomo direct showed average of 64.94±0.84 mGy and 37.64±1.20 mGy in left ovary part and average of 64.38±1.85 mGy and 32.96±1.11 mGy in right ovary part. This showed when executing Tomotherapy, measured scattered dose of Tomo Helical method which has relatively greater monitor units (MUs) and longer irradiation time are approximately 1.8 times higher than Tomo direct method. Scattered dose of left and right ovary of childbearing women is lower than ICRP recommended does which is not seriously worried level against the infertility and secondary cancer occurrence. However, as breast cancer occurrence ages become younger in the future and radiation therapy using high-precision image guidance equipment like Tomotherapy is developed, clinical follow-up studies about the ovary dose of childbearing women patients would be more required.

  8. Megavoltage cone beam computed tomography: commissioning and evaluation of patient dose

    International Nuclear Information System (INIS)

    Abou-elenein, Hassan S.; Attalla, Ehab M.; Ammar, H.; Eldesoky, Ismail; Farouk, Mohamed; Zaghloul, Mohamed S.

    2011-01-01

    The improvement in conformal radiotherapy techniques enables us to achieve steep dose gradients around the target which allows the delivery of higher doses to a tumor volume while maintaining the sparing of surrounding normal tissue. One of the reasons for this improvement was the implementation of intensity-modulated radio therapy (IMRT) by using linear accelerators fitted with multi-leaf collimator (MLC), Tomo therapy and Rapid arc. In this situation, verification of patient set-up and evaluation of internal organ motion just prior to radiation delivery become important. To this end, several volumetric image-guided techniques have been developed for patient localization, such as Siemens OPTIVUE/MVCB and MVision megavoltage cone beam CT (MV-CBCT) system. Quality assurance for MV-CBCT is important to insure that the performance of the Electronic portal image device (EPID) and MV-CBCT is suitable for the required treatment accuracy. In this work, the commissioning and clinical implementation of the OPTIVUE/MVCB system was presented. The geometry and gain calibration procedures for the system were described. The image quality characteristics of the OPTIVUE/MVCB system were measured and assessed qualitatively and quantitatively, including the image noise and uniformity, low-contrast resolution, and spatial resolution. The image reconstruction and registration software were evaluated. Dose at isocenter from CBCT and the EPID were evaluated using ionization chamber and thermo-luminescent dosimeters; then compared with that calculated by the treatment planning system (TPS- XiO 4.4). The results showed that there are no offsets greater than 1 mm in the flat panel alignment in the lateral and longitudinal direction over 18 months of the study. The image quality tests showed that the image noise and uniformity were within the acceptable range, and that a 2 cm large object with 1% electron density contrast can be detected with the OPTIVUE/MVCB system with 5 monitor units (MU

  9. A prospective, parallel group, open-labeled, comparative, multi-centric, active controlled study to evaluate the safety, tolerability and benefits of fixed dose combination of acarbose and metformin versus metformin alone in type 2 diabetes.

    Science.gov (United States)

    Jayaram, S; Hariharan, R S; Madhavan, R; Periyandavar, I; Samra, S S

    2010-11-01

    The present study was a prospective, parallel group, open-labeled, comparative, multicentric, active controlled study to evaluate the safety, tolerability and benefits of fixed dose combination of acarbose and metformin versus metformin alone in type 2 diabetic patients. A total of 229 patients with type 2 diabetes were enrolled at 5 medical centers across India. They received either acarbose (50 mg) + metformin (500 mg) bid/tid (n=115) or metformin monotherapy (500 mg) bid/ tid (n=114) for 12 weeks. Primary objective was to evaluate safety and tolerability based on the adverse events reported. Secondary objective was efficacy assessment based on changes in fasting, post prandial blood glucose and HbA1c values. In the acarbose + metformin group 10 patients reported 14 adverse events while in metformin group 9 patients reported 10 adverse events. No patient reported any serious adverse event or was withdraw from study because of adverse events. In the acarbose plus metformin group fasting blood glucose (FBG) decreased from a baseline of 158.85 +/- 18.14 mg/dl to 113.55 +/- 19.38 mg/dl (p fasting blood glucose decreased from a baseline of 158.31 +/- 26.53 mg/dl to 130.55 +/- 28.31 mg/dl (p < 0.0001) (decrease of 27.76 +/- 22.91 mg/dl) at 12 weeks. In the acarbose plus metformin group postprandial blood glucose (PPBG) decreased from a baseline of 264.65 +/- 34.03 mg/dl to 173.22 +/- 31.40 mg/dl (p < 0.0001) (decrease of 91.43 +/- 28.65 mg/dl) at 12 weeks, while in the metformin group PPBG decreased from a baseline of 253.56 +/- 36.28 mg/dl to 205.36 +/- 39.49 mg/dl (p < 0.0001) (decrease of 48.20 +/- 32.72 mg/dl) at 12 weeks. In the acarbose plus metformin group glycosylated haemoglobin (HbA1c) decreased from a baseline of 9.47 +/- 0.69% to 7.71 +/- 0.85% (p < 0.0001) (% decrease of 1.76 +/- 1.11) at 12 weeks, while in the metformin group HbAlc decreased from a baseline of 9.32 +/- 0.65% to 8.26 +/- 0.68% (p < 0.0001) (% decrease of 1.06 +/- 0.66) at 12 weeks. The

  10. Feasibility study for the assessment of the exposed dose with TENORM added in consumer products

    International Nuclear Information System (INIS)

    Yoo, Do Hyeon; Lee, Hyun Cheol; Shin, Wook-Geun; Min, Chul Hee; Ha, Wi-Ho; Yoo, Jae Ryong; Yoon, Seok-Won; Lee, Jiyon; Choi, Won-Chul

    2015-01-01

    Consumer products including naturally occurring radioactive material have been distributed widely in human life. The potential hazard of the excessively added technically enhanced naturally occurring radioactive material (TENORM) in consumer products should be assessed. The aim of this study is to evaluate the organ equivalent dose and the annual effective dose with the usage of the TENORM added in paints. The activities of gammas emitted from natural radionuclides in the five types of paints were measured with the high-purity germanium detector, and the annual effective dose was assessed with the computational human phantom and the Monte Carlo method. The results show that uranium and thorium series were mainly measured over the five paints. Based on the exposure scenario of the paints in the room, the highest effective dose was evaluated as <1 mSv y -1 of the public dose limit. (authors)

  11. Radiation doses to children during modified barium swallow studies

    International Nuclear Information System (INIS)

    Weir, Kelly A.; McMahon, Sandra M.; Long, Gillian; Bunch, Judith A.; Pandeya, Nirmala; Coakley, Kerry S.; Chang, Anne B.

    2007-01-01

    There are minimal data on radiation doses to infants and children undergoing a modified barium swallow (MBS) study. To document screening times, dose area product (DAP) and effective doses to children undergoing MBS and to determine factors associated with increased screening times and effective dose. Fluoroscopic data (screening time, DAP, kVp) for 90 consecutive MBS studies using pulse fluoroscopy were prospectively recorded; effective dose was calculated and data were analyzed for effects of behavior, number of swallow presentations, swallowing dysfunction and medical problems. Mean effective dose for the entire group was 0.0826 ± 0.0544 mSv, screening time 2.48 ± 0.81 min, and DAP 28.79 ± 41.72 cGy cm 2 . Significant differences were found across three age groups (≤1.0, >1.0-3.0 and >3.0 years) for effective dose (mean 0.1188, 0.0651 and 0.0529 mSv, respectively; P < 0.001), but not for screening time or DAP. Effective dose was correlated with screening time (P 0.007), DAP (P < 0.001), number of swallow presentations (P = 0.007), lower age (P = 0.017), female gender (P = 0.004), and height (P < 0.001). Screening time was correlated with total number of swallow presentations (P < 0.001) and DAP (P < 0.001). Screening times, DAP, effective dose, and child and procedural factors associated with higher effective doses are presented for children undergoing MBS studies. (orig.)

  12. Limiting CT radiation dose in children with craniosynostosis: phantom study using model-based iterative reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Kaasalainen, Touko; Lampinen, Anniina [University of Helsinki and Helsinki University Hospital, HUS Medical Imaging Center, Radiology, POB 340, Helsinki (Finland); University of Helsinki, Department of Physics, Helsinki (Finland); Palmu, Kirsi [University of Helsinki and Helsinki University Hospital, HUS Medical Imaging Center, Radiology, POB 340, Helsinki (Finland); School of Science, Aalto University, Department of Biomedical Engineering and Computational Science, Helsinki (Finland); Reijonen, Vappu; Kortesniemi, Mika [University of Helsinki and Helsinki University Hospital, HUS Medical Imaging Center, Radiology, POB 340, Helsinki (Finland); Leikola, Junnu [University of Helsinki and Helsinki University Hospital, Department of Plastic Surgery, Helsinki (Finland); Kivisaari, Riku [University of Helsinki and Helsinki University Hospital, Department of Neurosurgery, Helsinki (Finland)

    2015-09-15

    Medical professionals need to exercise particular caution when developing CT scanning protocols for children who require multiple CT studies, such as those with craniosynostosis. To evaluate the utility of ultra-low-dose CT protocols with model-based iterative reconstruction techniques for craniosynostosis imaging. We scanned two pediatric anthropomorphic phantoms with a 64-slice CT scanner using different low-dose protocols for craniosynostosis. We measured organ doses in the head region with metal-oxide-semiconductor field-effect transistor (MOSFET) dosimeters. Numerical simulations served to estimate organ and effective doses. We objectively and subjectively evaluated the quality of images produced by adaptive statistical iterative reconstruction (ASiR) 30%, ASiR 50% and Veo (all by GE Healthcare, Waukesha, WI). Image noise and contrast were determined for different tissues. Mean organ dose with the newborn phantom was decreased up to 83% compared to the routine protocol when using ultra-low-dose scanning settings. Similarly, for the 5-year phantom the greatest radiation dose reduction was 88%. The numerical simulations supported the findings with MOSFET measurements. The image quality remained adequate with Veo reconstruction, even at the lowest dose level. Craniosynostosis CT with model-based iterative reconstruction could be performed with a 20-μSv effective dose, corresponding to the radiation exposure of plain skull radiography, without compromising required image quality. (orig.)

  13. Technical background for shallow (skin) dose equivalent evaluations

    International Nuclear Information System (INIS)

    Ashley, J.C.; Turner, J.E.; Crawford, O.H.; Hamm, R.N.; Reaves, K.L.; McMahan, K.L.

    1991-01-01

    Department of Energy Order 5480.11 describes procedures for radiation protection for occupational workers. The revisions dealing with non-uniform exposure to the skin are the subject of this report. We describe measurements and analysis required to assess shallow (skin) dose equivalent from skin contamination. 6 refs., 4 tabs

  14. Evaluation of the repeated-dose liver and gastrointestinal tract micronucleus assays with 22 chemicals using young adult rats: summary of the collaborative study by the Collaborative Study Group for the Micronucleus Test (CSGMT)/The Japanese Environmental Mutagen Society (JEMS) - Mammalian Mutagenicity Study Group (MMS).

    Science.gov (United States)

    Hamada, Shuichi; Ohyama, Wakako; Takashima, Rie; Shimada, Keisuke; Matsumoto, Kazumi; Kawakami, Satoru; Uno, Fuyumi; Sui, Hajime; Shimada, Yasushi; Imamura, Tadashi; Matsumura, Shoji; Sanada, Hisakazu; Inoue, Kenji; Muto, Shigeharu; Ogawa, Izumi; Hayashi, Aya; Takayanagi, Tomomi; Ogiwara, Yosuke; Maeda, Akihisa; Okada, Emiko; Terashima, Yukari; Takasawa, Hironao; Narumi, Kazunori; Wako, Yumi; Kawasako, Kazufumi; Sano, Masaki; Ohashi, Nobuyuki; Morita, Takeshi; Kojima, Hajime; Honma, Masamitsu; Hayashi, Makoto

    2015-03-01

    The repeated-dose liver micronucleus (RDLMN) assay using young adult rats has the potential to detect hepatocarcinogens. We conducted a collaborative study to assess the performance of this assay and to evaluate the possibility of integrating it into general toxicological studies. Twenty-four testing laboratories belonging to the Mammalian Mutagenicity Study Group, a subgroup of the Japanese Environmental Mutagen Society, participated in this trial. Twenty-two model chemicals, including some hepatocarcinogens, were tested in 14- and/or 28-day RDLMN assays. As a result, 14 out of the 16 hepatocarcinogens were positive, including 9 genotoxic hepatocarcinogens, which were reported negative in the bone marrow/peripheral blood micronucleus (MN) assay by a single treatment. These outcomes show the high sensitivity of the RDLMN assay to hepatocarcinogens. Regarding the specificity, 4 out of the 6 non-liver targeted genotoxic carcinogens gave negative responses. This shows the high organ specificity of the RDLMN assay. In addition to the RDLMN assay, we simultaneously conducted gastrointestinal tract MN assays using 6 of the above carcinogens as an optional trial of the collaborative study. The MN assay using the glandular stomach, which is the first contact site of the test chemical when administered by oral gavage, was able to detect chromosomal aberrations with 3 test chemicals including a stomach-targeted carcinogen. The treatment regime was the 14- and/or 28-day repeated-dose, and the regime is sufficiently promising to incorporate these methods into repeated-dose toxicological studies. The outcomes of our collaborative study indicated that the new techniques to detect chromosomal aberrations in vivo in several tissues worked successfully. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

  15. Sodium phenylbutyrate in Huntington's disease: a dose-finding study.

    Science.gov (United States)

    Hogarth, Penelope; Lovrecic, Luca; Krainc, Dimitri

    2007-10-15

    Transcriptional dysregulation in Huntington's disease (HD) is mediated in part by aberrant patterns of histone acetylation. We performed a dose-finding study in human HD of sodium phenylbutyrate (SPB), a histone deacetylase inhibitor that ameliorates the HD phenotype in animal models. We used a dose-escalation/de-escalation design, using prespecified toxicity criteria and standard clinical and laboratory safety measures. The maximum tolerated dose was 15 g/day. At higher doses, toxicity included vomiting, lightheadedness, confusion, and gait instability. We saw no significant laboratory or electrocardiographic abnormalities. Gene expression changes in blood suggested an inverse dose-response. In conclusion, SPB at 12 to 15 g/day appears to be safe and well-tolerated in human HD. 2007 Movement Disorder Society

  16. Micro-dosing for early biokinetic studies in humans

    International Nuclear Information System (INIS)

    Stenstroem, K.; Sydoff, M.; Mattsson, S.

    2010-01-01

    Micro-dosing is a new concept in drug development that-if implemented in the pharmaceutical industry-would mean that new drugs can be tested earlier in humans than done today. The human micro-dosing concept-or 'Phase 0'-may offer improved candidate selection, reduced failure rates in the drug development line and a reduction in the use of laboratory animals in early drug development, factors which will help to speed up drug development and also reduce the costs. Micro-dosing utilises sub-pharmacological amounts of the substance to open opportunities for early studies in man. Three technologies are used for micro-dosing: accelerator mass spectrometry (AMS), positron emission tomography and liquid chromatography-tandem mass spectrometry. This paper focuses on the principle of AMS and discusses the current status of micro-dosing with AMS. (authors)

  17. Cosmic rays exposure during aircraft flight (3). Guideline and dose evaluation

    International Nuclear Information System (INIS)

    Yasuda, Hiroshi

    2007-01-01

    Radiation Council of MEXT drew up the Guideline of Cosmic Ray Exposure Control for Air Crew in 2006. The content of the Guideline and evaluation methods of dose are explained. The Guideline stated five items for Airline Company. It consists of 1) exposure dose control for air crew, 2) evaluation methods of cosmic rays exposure dose of air crew, 3) explanation and education of cosmic rays exposure for air crew, 4) reading, record and store of cosmic rays exposure dose of air crew, and 5) health control of air crew. The doses of four airlines were calculated by the Civil Aeromedical Research Institute (CARI) code and the European Program package for the Calculation of Aviation Route Doses (EPCARD) code. The difference of two codes was about 15 to 25%. Japanese Internet System for Calculation of Aviation Route Doses (JISCAED) has been developed by Japan. (S.Y.)

  18. The Evaluation of personnel radiation dose and society radiation on RSG-GAS around as proposal determination of ALARA value

    International Nuclear Information System (INIS)

    Pande Made Udiyani; Puradwi IW

    2007-01-01

    Each nuclear installation to achieve radiation safety has to meet the ALARA concepts. The ALARA value of a nuclear installation should be enacted by regulator body. ALARA value can be determined by evaluation radiation exposure and dose acceptance of nuclear installation operation. As case study in Indonesia, ALARA assessment in nuclear installation is done at RSG-GAS reactor. Intention of this research is to determine gyration reference assess ALARA by evaluate radiation dose acceptance by RSG-GAS radiation personnel and the influence of RSG-GAS operation to presentation of radiation accepted by society which living around its. ALARA of RSG-GAS determined based on evaluation of measurement data of the radiation doses which is accepted by personnel radiation. While evaluation of radiation doses which is accepted by society in the radius 5 km of the RSG-GAS conducted to data result of calculation using program package of CAP-88 and measurement result with method of carborne survey. Result of radiation dose evaluation obtained which not pass dose definition for the radiation worker that is 50 mSv/year, and for society around RSG-GAS that is 5 mSv/year. Based on the result of evaluation hence obtained value of ALARA for RSG-GAS in value of gyration 17 - 50 mSv/year. (author)

  19. Topics on study of low dose-effect relationship

    Energy Technology Data Exchange (ETDEWEB)

    Yamada, Takeshi [Toho Univ., School of Medicine, Tokyo (Japan); Ohyama, Harumi

    1999-09-01

    It is not exceptional but usually observed that a dose-effect relationship in biosystem is not linear. Sometimes, the low dose-effect relationship appears entirely contrary to the expectation from high dose-effect. This is called a 'hormesis' phenomena. A high dose irradiation inflicts certainly an injury on biosystem. No matter how low the dose may be, an irradiation might inflict some injury on biosystem according to Linear Non-Threshold hypothesis(LNT). On the contrary to the expectation, a low dose irradiation stimulates immune system, and promotes cell proliferation. This is called 'radiation hormesis'. The studies of the radiation hormesis are made on from four points of view as follows: (1) radiation adaptive response, (2) revitalization caused by a low dose stimulation, (3) a low dose response unexpected from the LNT hypothesis, (4) negation of the LNT hypothesis. The various empirical proofs of radiation hormesis are introduced in the report. (M . Suetake)

  20. A randomized, double-blind, placebo-controlled, parallel-group study to evaluate the efficacy and safety of the extended-release tramadol hydrochloride/acetaminophen fixed-dose combination tablet for the treatment of chronic low back pain.

    Science.gov (United States)

    Lee, Jae Hyup; Lee, Chong-Suh

    2013-11-01

    Chronic low back pain is a common condition that is often difficult to treat. The combination of tramadol hydrochloride and acetaminophen in an extended-release formulation has been shown to provide rapid and long-lasting analgesic effects resulting from the synergistic activity of these 2 active ingredients. The goal of this study was to evaluate the efficacy and safety of extended-release tramadol hydrochloride 75-mg/acetaminophen 650-mg fixed-dose combination tablets (TA-ER) for the treatment of chronic low back pain. This Phase III, double-blind, placebo-controlled, parallel-group study enrolled 245 patients with moderate to severe (≥4 cm on a 10-cm visual analog scale) chronic (≥3 months') low back pain insufficiently controlled by previous NSAIDs or cyclooxygenase-2-selective inhibitors and randomly assigned them to receive 4 weeks of either TA-ER or placebo. The primary efficacy end point was the percentage of patients with a pain intensity change rate ≥30% from baseline to final evaluation. Secondary end points included quality of life (Korean Short Form-36), functionality (Korean Oswestry Disability Index), and adverse events. The percentage of patients with a pain intensity change rate ≥30% was significantly higher (P Pain relief success rate from baseline was significantly higher with TA-ER versus placebo at days 8 and 15 but not at the final visit. Patients in the TA-ER group had significant improvements versus placebo in role-physical, general health, and reported health transition domains of the Korean Short Form-36 and significantly higher functional improvements in the personal care section of the Korean Oswestry Disability Index. Patient assessment of overall pain control as "very good" was also significantly higher with TA-ER than with placebo. Adverse events were reported more frequently with TA-ER than with placebo; the most common adverse events reported were nausea, dizziness, constipation, and vomiting. TA-ER was significantly more

  1. Fixed-dose combination PRO 160/120 of sabal and urtica extracts improves nocturia in men with LUTS suggestive of BPH: re-evaluation of four controlled clinical studies.

    Science.gov (United States)

    Oelke, Matthias; Berges, Richard; Schläfke, Sandra; Burkart, Martin

    2014-10-01

    To determine the effects of the herbal fixed-dose combination PRO 160/120 (extracts from saw palmetto fruits and stinging nettle roots) on nocturnal voiding frequency, as measured by question 7 of the IPSS questionnaire, in patients with moderate-to-severe LUTS/BPH after 24 weeks of treatment compared to placebo, to the α-blocker tamsulosin, or to the 5α-reductase inhibitor finasteride. The study is about post hoc evaluation of four published randomized, double-blind clinical trials on PRO 160/120, two compared with placebo, one with finasteride and one with tamsulosin. In addition, a pooled data analysis of the two placebo-controlled trials was conducted. We analyzed data from a total of 922 patients with a mean age of 66 years and a mean baseline nocturnal voiding frequency of 2.1. In the pooled analysis of placebo-controlled trials, nocturnal voids improved by 0.8 (29 %) with PRO 160/120 compared to 0.6 (18 %) with placebo (p = 0.015, Wilcoxon test, one-tailed). The 69 % responder rate to PRO 160/120 was significantly superior to the placebo response (52 %; p = 0.003, χ (2)-test, two-tailed). The majority of responders improved by 1 void/night. Absolute improvements and response rates were consistently higher with PRO 160/120 than with placebo over a range of baseline nocturnal voiding frequencies. There were no differences between PRO 160/120 and finasteride or tamsulosin regarding absolute improvement of nocturnal voids or responds rates. PRO 160/120 significantly improved nocturnal voiding frequency compared to placebo and similar to tamsulosin or finasteride.

  2. Dose response study of PVA-Fx gel for three dimensional dose distribution

    International Nuclear Information System (INIS)

    Brindha, S.; Ayyangar, Komanduri M.; Shen, Bin; Saw, Cheng B.

    2001-01-01

    Modern radiotherapy techniques involve complex field arrangements using conformal and intensity modulated radiation that requires three dimensional treatment planning. The verification of these plans poses even more challenge. In 1984, Gore et al., proposed that ferrous gel dosimeters combined with magnetic resonance imaging (MRI) could be used to measure three dimensional radiation dose distributions. Since then, there has been much interest in the development of gel dosimetry to aid the determination of three dimensional dose distributions during field arrangements. In this work, preparation and study of the MR characteristics of a PVA-Fx gel reported in the literature is presented

  3. Study of absorbed dose distribution to high energy electron beams

    International Nuclear Information System (INIS)

    Cecatti, E.R.

    1983-01-01

    The depth absorbed dose distribution by electron beams was studied. The influence of the beam energy, the energy spread, field size and design characteristics of the accelerator was relieved. Three accelerators with different scattering and collimation systems were studied leading todifferent depth dose distributions. A theoretical model was constructed in order to explain the increase in the depth dose in the build-up region with the increase of the energy. The model utilizes a three-dimensional formalism based on the Fermi-Eyges multiple scattering theory, with the introduction of modifications that takes into account the criation of secondary electrons. (Author) [pt

  4. Dose response of rat retinal microvessels to proton dose schedules used clinically: a pilot study

    International Nuclear Information System (INIS)

    Archambeau, John O.; Mao, Xiao W.; McMillan, Paul J.; Gouloumet, Vanessa L.; Oeinck, Steven C.; Grove, Roger; Yonemoto, Leslie T.; Slater, Jerry D.; Slater, James M.

    2000-01-01

    Purpose: This preclinical rat pilot study quantifies retinal microvessel, endothelial, and pericyte population changes produced by proton irradiation Methods and Materials: The left eyes of rats were irradiated with single doses of 8, 14, 20, and 28 Gy protons; right eyes, with two fractions. Animals were euthanized, and eyes were removed; elastase digests were prepared, and cell populations were counted in sample fields. Results were compared with unirradiated controls. Results: Progressive time- and dose-dependent endothelial cell loss occurred following all schedules. Cell loss was significantly different from control values (p 0 phase of the mitotic cycle. 28 Gy produced photoreceptor cell loss. Conclusion: The retinal digest is an elegant bioassay to quantify the microvessel population response. Single- and split-dose schedules appear to yield similar outcomes, in terms of endothelial cell density

  5. Evaluation of patient doses from upper gastrointestinal tract examinations based on the dosimetry in an anthropomorphic phantom

    International Nuclear Information System (INIS)

    Hirofuji, Yoshiaki; Aoyama, Takahiko; Koyama, Shuji; Kawaura, Chiyo

    2005-01-01

    The objective of this study was to evaluate organ dose and effective dose to patients from examinations of the upper gastrointestinal (GI) tract. Absorbed doses of various tissues and organs were measured using novel photodiode dosimeters installed in an anthropomorphic phantom representing a standard Japanese adult body. The organ dose and the effective dose were assessed from the absorbed doses according to the definitions seen in the publications of the International Commission on Radiological Protection. Dose measurements were performed for each projection of the upper GI tract examination in seven procedures at four hospitals and in a mobile coach, and organ and effective doses were assessed for each procedure. Organ doses obtained in the observation areas such as the stomach, esophagus and colon were in the order of several to more than 60 mGy, though they decreased to less than 1 mGy for tissues and organs distant from the observation areas. Organ doses and effective doses differed largely according to tube voltage, filtration and tube current or mAs value of the x-ray generator used, and by examination protocol, number of images, fluoroscopy time, and imaging units such as screen/film, computed radiography, digital radiography and flat panel detector. The number of images and the fluoroscopy time were 7 and 1.5 min for the examination in the mobile coach, and 18-22 and 2-6 min in the hospitals. Evaluated effective dose for the examination in the mobile coach was 2.9 mSv, and that in the hospitals ranged from 4.0-13.4 mSv at a ratio of more than three. (author)

  6. Computational and human observer image quality evaluation of low dose, knowledge-based CT iterative reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Eck, Brendan L.; Fahmi, Rachid; Miao, Jun [Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio 44106 (United States); Brown, Kevin M.; Zabic, Stanislav; Raihani, Nilgoun [Philips Healthcare, Cleveland, Ohio 44143 (United States); Wilson, David L., E-mail: dlw@case.edu [Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio 44106 and Department of Radiology, Case Western Reserve University, Cleveland, Ohio 44106 (United States)

    2015-10-15

    Purpose: Aims in this study are to (1) develop a computational model observer which reliably tracks the detectability of human observers in low dose computed tomography (CT) images reconstructed with knowledge-based iterative reconstruction (IMR™, Philips Healthcare) and filtered back projection (FBP) across a range of independent variables, (2) use the model to evaluate detectability trends across reconstructions and make predictions of human observer detectability, and (3) perform human observer studies based on model predictions to demonstrate applications of the model in CT imaging. Methods: Detectability (d′) was evaluated in phantom studies across a range of conditions. Images were generated using a numerical CT simulator. Trained observers performed 4-alternative forced choice (4-AFC) experiments across dose (1.3, 2.7, 4.0 mGy), pin size (4, 6, 8 mm), contrast (0.3%, 0.5%, 1.0%), and reconstruction (FBP, IMR), at fixed display window. A five-channel Laguerre–Gauss channelized Hotelling observer (CHO) was developed with internal noise added to the decision variable and/or to channel outputs, creating six different internal noise models. Semianalytic internal noise computation was tested against Monte Carlo and used to accelerate internal noise parameter optimization. Model parameters were estimated from all experiments at once using maximum likelihood on the probability correct, P{sub C}. Akaike information criterion (AIC) was used to compare models of different orders. The best model was selected according to AIC and used to predict detectability in blended FBP-IMR images, analyze trends in IMR detectability improvements, and predict dose savings with IMR. Predicted dose savings were compared against 4-AFC study results using physical CT phantom images. Results: Detection in IMR was greater than FBP in all tested conditions. The CHO with internal noise proportional to channel output standard deviations, Model-k4, showed the best trade-off between fit

  7. Evaluation on organ dose and image quality of lumber spine radiography using glass dosimeter

    International Nuclear Information System (INIS)

    Kim, Jae Kyeom; Kim, Jeong Koo

    2016-01-01

    The purpose of this study was to provide resources for medical exposure reduction through evaluation of organ dose and image resolution for lumbar spine around according to the size of the collimator in DR system. The size of the collimator were varied from 8″×17″ to 14″×17″ by 1″ in AP and lateral projection for the lumbar spine radiography with RANDO phantom. The organ dose measured for liver, stomach, pancreas, kidney and gonad by the glass dosimeter. The image resolution was analyzed using the Image J program. The organ dose of around lumbar spine were reduced as the size of the collimator is decreased in AP projection. There were no significant changes decreasing rate whenever the size of the collimator were reduced 1″ in the gonad. The organ dose showed higher on liver and kidney near the surface in lateral projection. There were decreasing rate of less than 5% in liver and kidney, but decreasing rate was 24.34% in the gonad whenever the size of the collimator were reduced 1″. Organ dose difference for internal and external of collimator measured 549.8 μGy in the liver and 264.6 μGy in the stomach. There were no significant changes organ dose difference that measured 1,135.1 μG in the gonad. Image Quality made no difference because SNR and PSNR were over than 30 dB when the collimator size is less than 9″×17″ on AP projection and 10″×17″ on lateral projection. Therefore, we are considered that the recommendations criterion for control of collimator were suggested in order to reduce unnecessary X-ray exposure and to obtain good image quality because lumbar spine radiography contains a lot of peripheral organs rather than other area radiography

  8. Evaluation of occupational exposure in intraoral radiography; Avaliacao da dose ocupacional em radiografia intraoral

    Energy Technology Data Exchange (ETDEWEB)

    Miguel, Cristiano; Barros, Frieda S.; Rocha, Anna S.P.S.; Godoi, Walmor C., E-mail: miguel_cristianoch@yahoo.com.br, E-mail: saicla@utfpr.edu.br, E-mail: annarocha@yahoo.com, E-mail: walmor.godoi@gmail.com [Universidade Tecnologica Federal do Parana (UTFPR), Curitiba, PR (Brazil); Tilly Junior, Joao G., E-mail: joao.tilly@derax.com.br [Universidade Federal do Parana (HC/UFPR), Curitiba, PR (Brazil). Hospital das Clinicas

    2014-07-01

    The intraoral radiography is widely performed in the dental office due to low cost and agility. The doses in intraoral radiology are considered low, however it is known that doses below the threshold for deterministic radiation has the potential to induce stochastic effects. An intraoral radiography has a risk of inducing fatal cancer or serious in order of 1:10,000,000. Besides the patient, the dentist may also be being exposed to radiation during the work with the radiographics practices. The bibliographies demonstrates the lack of information on radiation protection of dentists, however, the occupational dose reduction was observed in radiology over the past 14 years. This work aims to evaluate the effective dose of radiation to which workers can be exposed dentists in dental offices to perform intraoral radiographs. In this context, a study was be conducted between June 2013 and May 2014 with 44 professionals in Curitiba city. For each dentist was given a personal dosimeter to be used for 30 days. During this period, the number of radiographies and the length of the cable triggers of the X-ray equipment was registered and, the dosimeter´s dose was read. It was observed that the cables triggers meet regulatory standards and allow dentists to get the mean minimum distance of two meters from the radiation source in 93% of cases. Through analysis of the doses, it was concluded that occupational exposures of these workers are within the recommended threshold by regulatory 453/1998 of the Ministry of Health from Brazil. (author)

  9. Applicability of the tissue stem cell turnover concept on the validity of cumulative dose based radiation risk evaluation

    International Nuclear Information System (INIS)

    Otsuka, Kensuke; Hamada, Nobuyuki; Iwasaki, Toshiyasu; Yoshida, Kazuo

    2011-01-01

    The radiation protection system adopts the linear no-threshold model to achieve proper radiation protection for considering cancer risks resulting from radiation exposure. This model uses cumulative dose to a tissue for risk evaluation in which cumulative dose is related to the amount of DNA damage and consequential induction of gene mutation. In this concept, gene mutation accumulates in tissue stem cells, the putative target of carcinogenesis, with total dose given to the tissue. Unlike high-dose-rate exposure, epidemiological studies in high radiation background areas, such as Kerala in India, revealed that cancer risks is not elevated by the dose to the inhabitants, suggesting that there exists some mechanisms to eliminate the damage/mutation in the exposed tissue under extremely low-dose-rate exposure situations. In this report, the dynamics of tissue stem cell turnover is evaluated as a possible mechanism under extremely low-dose-rate exposure situations. To this end, we reviewed recent literatures studying tissue stem cell turnover, and found that great advances in stem cell research have made it possible to trace a fate of stem cells in tissues. Furthermore, turnover of tissue stem cells is found to occur after irradiation, due to competition of stem cells within tissues. This raises a possibility that radiation effects may not accumulate in a tissue depending on the dose-rate and duration of exposure period. (author)

  10. An effective dose of ketamine for eliminating pain during injection of propofol: a dose response study.

    Science.gov (United States)

    Wang, M; Wang, Q; Yu, Y Y; Wang, W S

    2013-09-01

    Ketamine can completely eliminate pain associated with propofol injection. However, the effective dose of ketamine to eliminate propofol injection pain has not been determined. The purpose of this study was to determine the effective dose of ketamine needed to eliminate pain in 50% and 95% of patients (ED50 and ED95, respectively) during propofol injections. This study was conducted in a double-blinded fashion and included 50 patients scheduled for elective gynecological laparoscopy under general anesthesia. The initial dose of ketamine used in the first patient was 0.25mg/kg. The dosing modifications were in increments or decrements of 0.025 mg/kg. Ketamine was administered 15 seconds before injecting propofol (2.5mg/kg), which was injected at a rate of 1mL/s. Patients were asked to rate their pain during propofol injection every 5s econds using a 0-3 pain scale. The highest pain score was recorded. The ED50, ED95 and 95% confidence intervals (CI) were determined by probit analyses. The dose of ketamine ranged from 0.175 to 0.275 mg/kg. The ED50 and ED95 of ketamine for eliminating pain during propofol injection were 0.227 mg/kg and 0.283 mg/kg, respectively (95%CI: 0.211-0.243 mg/kg and 0.26-0.364 mg/kg, respectively). Ketamine at an approximate dose of 0.3mg/kg was effective in eliminating pain during propofol injection. Copyright © 2013 Société française d’anesthésie et de réanimation (Sfar). Published by Elsevier SAS. All rights reserved.

  11. Evaluation of the Entrance Surface Dose (ESD and Radiation Dose to the Radiosensitive Organs in Pediatric Pelvic Radiography

    Directory of Open Access Journals (Sweden)

    Vahid Karami

    2017-06-01

    Full Text Available Background Patients' dosimetry is crucial in order to enhance radiation protection optimization and to deliver low radiation dose to the patients in a radiological procedure. The aim of this study was to assess the entrance surface dose (ESD and radiation dose to the radiosensitive organs in pediatric pelvic radiography. Materials and Methods The studied population included 98 pediatric patients of both genders referred to anteroposterior (AP projection of pelvic radiography. The radiation dose was directly measured using high radiosensitive cylindrical lithium fluoride thermo-luminescent dosimeters (TLD-GR200. Two TLDs were placed at the center point of the radiation field to measure the ESD of pelvis. Moreover for each patient, 2 TLDs were placed upon each eyelid, 2 TLDs upon each breast, 2 TLDs upon the surface anatomical position of the thyroid gland and finally 2 TLDs at the surface anatomical position of the gonads to measure the received dose. Results The ESD ± standard deviation for AP pelvic radiography was obtained 591.7±76 µGy. Statistically significant difference was obtained between organs located outside and inside of the radiation field with respect to dose received (P

  12. Evaluation of various boluses in dose distribution for electron therapy of the chest wall with an inward defect

    Science.gov (United States)

    Mahdavi, Hoda; Jabbari, Keyvan; Roayaei, Mahnaz

    2016-01-01

    Delivering radiotherapy to the postmastectomy chest wall can be achieved using matched electron fields. Surgical defects of the chest wall change the dose distribution of electrons. In this study, the improvement of dose homogeneity using simple, nonconformal techniques of thermoplastic bolus application on a defect is evaluated. The proposed phantom design improves the capability of film dosimetry for obtaining dose profiles of a patient's anatomical condition. A modeled electron field of a patient with a postmastectomy inward surgical defect was planned. High energy electrons were delivered to the phantom in various settings, including no bolus, a bolus that filled the inward defect (PB0), a uniform thickness bolus of 5 mm (PB1), and two 5 mm boluses (PB2). A reduction of mean doses at the base of the defect was observed by any bolus application. PB0 increased the dose at central parts of the defect, reduced hot areas at the base of steep edges, and reduced dose to the lung and heart. Thermoplastic boluses that compensate a defect (PB0) increased the homogeneity of dose in a fixed depth from the surface; adversely, PB2 increased the dose heterogeneity. This study shows that it is practical to investigate dose homogeneity profiles inside a target volume for various techniques of electron therapy. PMID:27051169

  13. Absorbed dose/melting heat dependence studies for the PVDF homopolymer

    International Nuclear Information System (INIS)

    Batista, Adriana S.M.; Gual, Maritza R.; Pereira, Claubia

    2013-01-01

    Differential Scanning Calorimetry (DSC) of gamma irradiated Poly (vinylidene Fluoride) [PVDF] homopolymer has been studied in connection with the use of material in industrial high gamma dose measurement. Interaction between gamma radiation and PVDF leads to the radio-induction of C=O and conjugated C=C bonds, as it can be inferred from previous infrared (FTIR) and ultraviolet-visible (UV-Vis) spectrometric data. These induced defects result in a decrease of the polymer crystallinity that can be followed with DSC scans, by measuring the latent heat during the melting transition (Hmelt). After a systematic investigation, we have found that Hmelt is unambiguously related to the delivered doses ranging from 100 to 2,000 kGy of gamma radiation. One the other hand, further fading investigation analysis has proved that the Hmelt x Dose relationship can be fitted by an exponential function that remains constant for several months. Both the very large range of dose measurement and also the possibility of evaluating high gamma doses until five months after irradiation make PVDF homopolymers very good candidates to be investigated as commercial high gamma dose dosimeters. The high gamma dose irradiation facilities in Brazil used to develop high dose dosimeters are all devoted to industrial and medical purposes. Therefore, in view of the uncertainties involved in the dose measurements related to the electronic equilibrium correction factors and backscattering in the isodose curves used at the irradiation setup, a validation process is required to correctly evaluate the delivered absorbed doses. The sample irradiations were performed with a Co-60 source, at 12kGy/h and 2,592 kGy/h, in the high gamma dose facilities at Centro de Desenvolvimento da Tecnologia Nuclear CDTN/CNEN, Belo Horizonte, Brazil. The comparison of the curve of the Hmelt vs Dose is presented in this paper. (author)

  14. Dose profile study in head CT scans using radiochromic films

    Energy Technology Data Exchange (ETDEWEB)

    Ladino G, A. M.; Prata M, A., E-mail: amlgphys@gmail.com [Universidade Federal de Minas Gerais, Departamento de Engenharia Nuclear, Av. Pte. Antonio Carlos 6627, 31270-901 Belo Horizonte, Minas Gerais (Brazil)

    2016-10-15

    Diagnostic images of computed tomography generate higher doses than other methods of diagnostic radiology using X-ray beam attenuation. Clinical applications of CT have been increased by technological advances, what leads to a wide variety of scanner in the Brazilian technological pool. It has been difficult to implement dose reduction strategies because of the lack of proper guidance on computed tomography examinations. However, CT scanners allow adjusting acquisition parameter according to the patients physical profile and diagnostic application for which the scan is intended. The knowledge of the dose distribution is important because changes in image acquisition parameters may provide dose reduction. In this study, it was used a cylindrical head phantom in PMMA with 5 openings, what allows dose measurement in 5 regions. In a GE CT scanner, Discovery model of 64 channels, the central slice of the head phantom was irradiated and the absorbed doses were measured using a pencil ionization chamber. Radiochromic film strips were placed in the peripheral and in the central region of the head phantom and was performed a scan of 10 cm in the phantom central region. The scan was performed using the head scanning protocol of the radiobiology service, with a voltage of 120 kV. After scanning, the radiochromic film strips were digitalized and their digital images were used to have the dose longitudinal profiles. The dose values recorded have variation in a range of 18.66 to 23.57 mGy. In the results it was compared the dose index values obtained by the pencil chamber measurement to the dose longitudinal profiles recorded by the film strips. (Author)

  15. Dose profile study in head CT scans using radiochromic films

    International Nuclear Information System (INIS)

    Ladino G, A. M.; Prata M, A.

    2016-10-01

    Diagnostic images of computed tomography generate higher doses than other methods of diagnostic radiology using X-ray beam attenuation. Clinical applications of CT have been increased by technological advances, what leads to a wide variety of scanner in the Brazilian technological pool. It has been difficult to implement dose reduction strategies because of the lack of proper guidance on computed tomography examinations. However, CT scanners allow adjusting acquisition parameter according to the patients physical profile and diagnostic application for which the scan is intended. The knowledge of the dose distribution is important because changes in image acquisition parameters may provide dose reduction. In this study, it was used a cylindrical head phantom in PMMA with 5 openings, what allows dose measurement in 5 regions. In a GE CT scanner, Discovery model of 64 channels, the central slice of the head phantom was irradiated and the absorbed doses were measured using a pencil ionization chamber. Radiochromic film strips were placed in the peripheral and in the central region of the head phantom and was performed a scan of 10 cm in the phantom central region. The scan was performed using the head scanning protocol of the radiobiology service, with a voltage of 120 kV. After scanning, the radiochromic film strips were digitalized and their digital images were used to have the dose longitudinal profiles. The dose values recorded have variation in a range of 18.66 to 23.57 mGy. In the results it was compared the dose index values obtained by the pencil chamber measurement to the dose longitudinal profiles recorded by the film strips. (Author)

  16. Evaluation of absorbed dose-distribution in the X-ray or gamma-irradiator for blood products

    International Nuclear Information System (INIS)

    Moriyama, Satoshi; Kurihara, Katsuhiko; Yokokawa, Nobuhiko; Satake, Masahiro; Juji, Takeo

    2001-01-01

    Irradiation of blood products abrogates the proliferation of lymphocytes present in cellular component, which is currently the only accepted methodology to prevent transfusion-associated graft versus host disease (TA-GVHD). A range of irradiation dose levels between 15 Gy and 50 Gy is being used, but the majority of facilities are employing 15 Gy. It should, however, be recognized that the delivered dose in the instrument canister might differ from the actual dose absorbed by the blood bag. This study have evaluated the actual dose distribution under practical conditions where a container was loaded with blood products or water bags, or filled with distilled water. This approach provides data that the maximum attenuation occurred when the container was completely filled with a blood-compatible material. Thus, an error of approximately 20 percent should be considered in the dose measured in the in-air condition. A dose calibration in an in-air condition may lead to substantial underexposure of the blood products. A dose distribution study using adequately prearranged exposure period verified that the absorbed dose of 15 Gy was attained at any point in the container for both linear accelerator and gamma-irradiator. The maximal difference in the absorbed dose between measured points was 1.5- and 1.6-fold for linear accelerator and gamma-irradiator, respectively. In conclusion, using blood-compatible materials, a careful dose calibration study should be employed in which the absorbed dose of 15 Gy is obtained at the point where the lowest dose could be expected. (author)

  17. Measurement of radioactive aerosol behavior during dismantling and reflection to the exposure dose evaluation - 16107

    International Nuclear Information System (INIS)

    Iguchi, Yukihiro; Kato, Masami

    2009-01-01

    Radioactive aerosol disperses slightly via contamination prevention systems such as control enclosures and filters when the nuclear installation is dismantled, and it might impact the environment. Therefore, when decommissioning is planned, it is necessary to assess the safety such as exposure dose evaluation to the public. For the radioactive aerosol, it is possible that the dispersion ratio is different according to the contamination condition, the dismantlement method of the material, nuclides (elements), etc. The radiation exposure evaluation for the decommissioning plan has been executed by operators in Japan based on a number of experiments (mostly cold tests) and overseas results. The decommissioning is now being carried out at the Tokai Power Station (GCR) and Fugen Decommissioning Engineering Center in Japan. In this study, the results data is acquired at the decommissioning sites, and the methodology and data for the exposure dose evaluation are verified and confirmed. These examination results will lead to the upgrading and improvement of the exposure evaluation methodology. In particular, the dismantlement work of connected piping of the heat exchanger (steam generator) was executed in the Tokai Power Station in 2008. In this study, we paid attention to the radionuclides of Co-60 and Cs-137 that adhered to piping, and the dispersion behavior of aerosol was measured and contamination prevention effect was assured. As a result, the data show that the cesium concentrates about four times higher than cobalt. Moreover, the effects of the prevention measures of contamination were confirmed and the behavior of the radioactive aerosol became clear and the effective findings about the dose evaluation of the dismantling were collected. (authors)

  18. Evaluation of Skin Dose and Image Quality on Cone Beam Computed Tomography

    International Nuclear Information System (INIS)

    Ahn, Jong Ho; Hong, Chae Seon; Kim, Jin Man; Jang, Jun Young

    2008-01-01

    Cone-beam CT using linear accelerator attached to on-board imager is a image guided therapy equipment. Because it is to check the patient's set-up error, correction, organ and target movement. But imaging dose should be cause of the secondary cancer when taking a image. The aim of this study is investigation of appropriate cone beam CT scan mode to compare and estimate the image quality and skin dose. Measurement by Thermoluminescence dosimeter (TLD-100, Harshaw) with using the Rando phantom are placed on each eight sites in separately H and N, thoracic, abdominal section. each 4 methods of scan modes of are measured the for skin dose in three time. Subsequently, obtained average value. Following image quality QA protocol of equipment manufacturers using the catphan 504 phantom, image quality of each scan mode is compared and analyzed. The results of the measured skin dose are described in here. The skin dose of Head and Neck are measured mode A: 8.96 cGy, mode B: 4.59 cGy, mode C: 3.46 cGy mode D: 1.76 cGy and thoracic mode A: 9.42 cGy, mode B: 4.58 cGy, mode C: 3.65 cGy, mode D: 1.85 cGy, and abdominal mode A: 9.97 cGy, mode B: 5.12 cGy, mode C: 4.03 cGy, mode D: 2.21 cGy. Approximately, dose of mode B are reduced 50%, mode C are reduced 60%, mode D are reduced 80% a point of reference dose of mode A. the results of analyzed HU reproducibility, low contrast resolution, spatial resolution (high contrast resolution), HU uniformity in evaluation item of image quality are within the tolerance value by recommended equipment manufacturer in all scan mode. Maintaining the image quality as well as reducing the image dose are very important in cone beam CT. In the result of this study, we are considered when to take mode A when interested in soft tissue. And we are considered to take mode D when interested in bone scan and we are considered to take mode B, C when standard scan. Increasing secondary cancer risk due to cone beam CT scan should be reduced by low m

  19. Technology Development for Radiation Dose Measurement and Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Bong Hwan; Chang, S. Y.; Lee, T. Y. (and others)

    2007-06-15

    The correction factors essential for the operation of In-Vivo counting system were produced and implemented into a field operation for the improvement of accuracy in measurement of the radioactivity inside a human body. The BiDAS2007 code which calculate an internal dose was developed by upgrading the former code prepared in the previous stage of this project. The method of using the multibioassy data, the maximum likelihood function and the Bayesian statistics were established to an internal dose based on the measurement data of radioactivity, intakes and retention of radioactivity in a human body and it can improve the accuracy in estimation of the intakes of radioactivity and the committed effective dose equivalent. In order to solve the problem of low detection efficiency of the conventional Bonner Sphere (BS) to a high energy neutron, the extended BS's were manufactured and the technique for neutron field spectrometry was established. The fast neutron and gamma spectrometry system with a BC501A scintillation detector was also prepared. Several neutron fluence spectra at several nuclear facilities were measured and collected by using the extended BS. The spectrum weighted responses of some neutron monitoring instruments were also derived by using these spectra and the detector response functions. A high efficient TL material for the neutron personal dosimeter was developed. It solved the main problem of low thermal stability and high residual dose of the commercial TLDs and has the sensitivity to neutron and to gamma radiation with 40 and 10 times higher respectively than them.

  20. Feasibility study of radiophotoluminescent glass rod dosimeter postal dose intercomparison for high energy photon beam

    International Nuclear Information System (INIS)

    Rah, Jeong-Eun; Kim, Siyong; Cheong, Kwang-Ho; Lee, Jeong-Woo; Chung, Jin-Beom; Shin, Dong-Oh; Suh, Tae-Suk

    2009-01-01

    A radiophotoluminescent glass rod dosimeter (GRD) system has recently become commercially available. In this study we evaluated whether the GRD would be suitable for external dosimetric audit program in radiotherapy. For this purpose, we introduced a methodology of the absorbed dose determination with the GRD by establishing calibration coefficient and various correction factors (non-linearity dose response, fading, energy dependence and angular dependence). A feasibility test of the GRD postal dose intercomparison was also performed for eight high photon beams by considering four radiotherapy centers in Korea. In the accuracy evaluation of the GRD dosimetry established in this study, we obtained within 1.5% agreements with the ionization chamber dosimetry for the 60 Co beam. It was also observed that, in the feasibility study, all the relative deviations were smaller than 3%. Based on these results, we believe that the new GRD system has considerable potential to be used for a postal dose audit program

  1. Three-dimensional dose distribution in contrast-enhanced digital mammography using Gafchromic XR-QA2 films: Feasibility study

    International Nuclear Information System (INIS)

    Hwang, Yi-Shuan; Lin, Yu-Ying; Cheung, Yun-Chung; Tsai, Hui-Yu

    2014-01-01

    This study was aimed to establish three-dimensional dose distributions for contrast-enhanced digital mammography (CEDM) using self-developed Gafchromic XR-QA2 films. Dose calibration and distribution evaluations were performed on a full-field digital mammography unit with dual energy (DE) contrast-enhanced option. Strategy for dose calibration of films in the DE mode was based on the data obtained from common target/filter/kVp combinations used clinically and the dose response model modified from Rampado's model. Dose derived from films were also verified by measured data from an ionization chamber. The average difference of dose was 8.9% in the dose range for clinical uses. Three-dimensional dose distributions were estimated using triangular acrylic phantom equipped with the mammography system. Five pieces of film sheets were separately placed between the acrylic slabs to evaluate the dose distribution at different depths. After normalizing the dose in each pixel to the maximum dose at the top-center position of the acrylic, normalized dose distribution for transverse, coronal and sagittal planes, could thus be obtained. The depth dose distribution evaluated in this study may further serve as a reference for evaluating the patient glandular dose at different depths based on the entrance exposure information. - Highlights: • CEDM techniques can enhance contrast uptake areas and suppress background tissue. • Dose for the dual-energy acquisition is about 20% higher than standard mode. • A new method is proposed to estimate the 3D dose distribution in dual-energy CEDM. • Depth of normalized dose ratio of 0.5 is less than but near 1 cm in the DE mode

  2. Identification and dose evaluation of irradiated beef containing bones

    International Nuclear Information System (INIS)

    Mangiacotti, M.; Alberti, A.; Fuochi, P.G.; Chiesa, L.M.

    2011-01-01

    Complete text of publication follows. Food irradiation is a well-established technique to extend the food shelf life and to reduce the food-related health hazards caused by pathogenic micro-organisms. At present, radiation treatment is permitted for various categories of food and food ingredients in many countries. At the European level, irradiation of food is regulated by the European Directives 1999/2/EC and 1999/3/EC. Community legislation states that any food or food ingredients, authorised in the European Union, must be labelled with the word 'irradiated' and that every year each Member State has to carry out checks at the product marketing stage to enforce correct labelling. The present work aimed at identifying irradiated beef meat by using a reliable and sensitive detection of DNA comets as screening biological method and performing an Electron Spin Resonance (ESR) spectrometry as confirmatory qualitative standard. The influence of storage conditions and time after irradiation on DNA degradation was also investigated. Furthermore the application of ESR technique as a quantitative method was successfully applied to beef bones, using the approach of calibration curve. Results, although the limited statistics, proved for reliability of the dose reconstruction method and blind tests were carried out resulting in very satisfactory difference between actual treatment dose and reconstructed dose.

  3. Phase I dose-finding study of cabazitaxel administered weekly in patients with advanced solid tumours

    International Nuclear Information System (INIS)

    Fumoleau, Pierre; Trigo, Jose Manuel; Isambert, Nicolas; Sémiond, Dorothée; Gupta, Sunil; Campone, Mario

    2013-01-01

    Cabazitaxel is approved in patients with metastatic hormone-refractory prostate cancer previously treated with a docetaxel-containing regimen. This study evaluated a weekly cabazitaxel dosing regimen. Primary objectives were to report dose-limiting toxicities (DLTs) and to determine the maximum tolerated dose (MTD). Efficacy, safety and pharmacokinetics were secondary objectives. Cabazitaxel was administered weekly (1-hour intravenous infusion at 1.5–12 mg/m2 doses) for the first 4 weeks of a 5-week cycle in patients with solid tumours. Monitoring of DLTs was used to determine the MTD and the recommended weekly dose. Thirty-one patients were enrolled. Two of six patients experienced DLTs at 12 mg/m 2 , which was declared the MTD. Gastrointestinal disorders were the most common adverse event. Eight patients developed neutropenia (three ≥ Grade 3); one occurrence of febrile neutropenia was reported. There were two partial responses (in breast cancer) and 13 patients had stable disease (median duration of 3.3 months). Increases in C max and AUC 0–t were dose proportional for the 6–12 mg/m 2 doses. The MTD of weekly cabazitaxel was 12 mg/m 2 and the recommended weekly dose was 10 mg/m 2 . The observed safety profile and antitumour activity of cabazitaxel were consistent with those observed with other taxanes in similar dosing regimens. The study was registered with ClinicalTrials.gov as http://www.clinicaltrials.gov/ct2/show/NCT01755390

  4. Realization of 3D evaluation algorithm in dose-guided radiotherapy

    International Nuclear Information System (INIS)

    Wang Yu; Li Gui; Wang Dong; Wu Yican; FDS Team

    2012-01-01

    3D evaluation algorithm instead of 2D evaluation method of clinical dose verification is highly needed for dose evaluation in Dose-guided Radiotherapy. 3D evaluation algorithm of three evaluation methods, including Dose Difference, Distance-To-Agreement and 7 Analysis, was realized by the tool of Visual C++ according to the formula. Two plans were designed to test the algorithm, plan 1 was radiation on equivalent water using square field for the verification of the algorithm's correctness; plan 2 was radiation on the emulation head phantom using conformal field for the verification of the algorithm's practicality. For plan 1, the dose difference, in the tolerance range has a pass rate of 100%, the Distance-To-Agreement and 7 analysis was of a pass rate of 100% in the tolerance range, and a pass rate of 99±1% at the boundary of range. For plan 2, the pass rate of algorithm were 88.35%, 100%, 95.07% for the three evaluation methods, respectively. It can be concluded that the 3D evaluation algorithm is feasible and could be used to evaluate 3D dose distributions in Dose-guided Radiotherapy. (authors)

  5. In vitro study of dose rate effect on Leksell Gamma Knife Perfexion

    International Nuclear Information System (INIS)

    Pastykova, V.; Novotny, J. jr.; Vachelova, J.; Davidkova, M.; Liscak, R.

    2018-01-01

    The main purpose of the study is to evaluate the radiobiological effect of the dose rate changes in Leksell Gamma Knife (LGK) clinical conditions. In principle there are two reasons why dose rate on LGK is reduced during patient irradiation: 1) Co-60 sources decay with a half-life of 5.26 years and 2) using multiple iso-centers and conformal treatment plans (e.g. with blocked beams). This pilot study is an experimental work performed in vitro with medulloblastoma DAOY cells. Are there effects caused by low dose rate which could negatively influence the clinical outcome of the radiosurgery? (authors)

  6. Evaluation of patient absorbed dose in a PET-CT test

    Energy Technology Data Exchange (ETDEWEB)

    Guerra P, F.; Mourao F, A. P. [Federal University of Minas Gerais, Department of Nuclear Engineering, Av. Antonio Carlos 6627, CEP 31270-901, Pampulha, Belo Horizonte, Minas Gerais (Brazil); Santana, P. C., E-mail: fgpaiva92@gmail.com [Federal University of Minas Gerais, Medical School, Av. Prof. Alfredo Balena 190, CEP 30123970, Santa Efigenia, Belo Horizonte, Minas Gerais (Brazil)

    2017-10-15

    Images of PET-CT has important diagnostic applications, especially in oncology. This equipment allows overlapping of functional images obtained from the administration of radionuclides and anatomical, generated by X-rays. The PET-CT technique may generate higher doses in patients due to the fact that two diagnostic modalities are used in a single examination. A whole body CT scan is performed and in sequence, a capture of the signal generated by the photons emitted is done. In this study, the absorbed and effective doses generated by the CT scan and incorporated by the administration of the radionuclide were evaluated in 19 organs. To evaluate the CT dose, 32 radiochromic film strips were correctly positioned into the anthropomorphic male phantom. The CT protocol performed was whole-body scanning and a high-resolution lung scan. This protocol is currently used in most services. The calculation of the effective dose from the injected activity in the patient was performed using the ICRP 106 Biokinetic model (ICRP 106, 2008). The activity to be injected may vary according to the patients body mass and with the sensitivity of the detector. The mass of the simulator used is 73.5 kg, then the simulation with and injected activity of 244.76 MBq was used. It was observed that 87.4% of the effective dose in examination PET/CT comes from the CT scans, being 63.8% of the whole body scan and 23.6% of high resolution lung scan. Using activity of 0.09 mCi x kg {sup 18}F-FDG radiopharmaceutical contributes only 12.6% of the final effective dose. As a conclusion, it was observed that the dose in patients submitted to the {sup 18}F-FDG PET-CT examination is high, being of great value efforts for its reduction, such as the use of appropriate image acquisition techniques and promoting the application of the principle of optimization of practice. (Author)

  7. Evaluation of axillary dose coverage following whole breast radiotherapy: Variation with the breast volume and shape

    International Nuclear Information System (INIS)

    Aguiar, Artur; Gomes Pereira, Helena; Azevedo, Isabel; Gomes, Luciano

    2015-01-01

    Objective: To evaluate the axillary dose coverage in patients treated with tridimensional whole breast radiotherapy (3D-WBRT), according to the breast volume and shape in treatment position. Background: Several studies have demonstrated an insufficient dose contribution to the axillary levels, using 3D-WBRT, remaining unclear whether the breast volume and shape can influence it. Materials and methods: We retrospectively delineated the axillary levels on planning CT-images of 100 patients, treated with 3D-WBRT along 2012 in our institution. To estimate the shape we established an anatomic CT-based interval, defined as the Thoracic Extent (TE). The breast volume matched its CTV. Mean dose levels and V95 (volume receiving at least 95% of the prescribed dose) were evaluated. Results: Mean axillary level I (A1), II (A2) and III (A3) volume was 56.1 cc, 16.5 cc and 18.9 cc, respectively, and mean doses were 43.9 Gy, 38.6 Gy and 19.5 Gy. For breast volumes of <800 cc, 800–999 cc, 1000–1199 cc and >1200 cc, mean A1 V95 was 38%, 51%, 61.2% and 57.2% whereas median A2 V95 was 8.3%, 13.4%, 19.4% and 28% respectively. Regarding shape, where the breast relative position to the TE was categorized in intervals between 31% and 40%, 41% and 50%, 51% and 60%, and 61% and 70%, mean A1 V95 was 38.7%, 43.1%, 51.1% and 77.3% whereas mean A2 V95 was 6.1%, 11.2%, 17.1% and 37% respectively. Conclusions: We observed inadequate dose coverage to all axillary levels, even after applying a sub-analysis accounting for different breast volumes and shapes. Although higher doses were associated with the more voluminous and pendulous breasts, axillary coverage with 3D-WBRT seems to be inefficient, regardless of the breast morphology

  8. Dosimetric evaluation of photon dose calculation under jaw and MLC shielding

    International Nuclear Information System (INIS)

    Fogliata, A.; Clivio, A.; Vanetti, E.; Nicolini, G.; Belosi, M. F.; Cozzi, L.

    2013-01-01

    Purpose: The accuracy of photon dose calculation algorithms in out-of-field regions is often neglected, despite its importance for organs at risk and peripheral dose evaluation. The present work has assessed this for the anisotropic analytical algorithm (AAA) and the Acuros-XB algorithms implemented in the Eclipse treatment planning system. Specifically, the regions shielded by the jaw, or the MLC, or both MLC and jaw for flattened and unflattened beams have been studied.Methods: The accuracy in out-of-field dose under different conditions was studied for two different algorithms. Measured depth doses out of the field, for different field sizes and various distances from the beam edge were compared with the corresponding AAA and Acuros-XB calculations in water. Four volumetric modulated arc therapy plans (in the RapidArc form) were optimized in a water equivalent phantom, PTW Octavius, to obtain a region always shielded by the MLC (or MLC and jaw) during the delivery. Doses to different points located in the shielded region and in a target-like structure were measured with an ion chamber, and results were compared with the AAA and Acuros-XB calculations. Photon beams of 6 and 10 MV, flattened and unflattened were used for the tests.Results: Good agreement between calculated and measured depth doses was found using both algorithms for all points measured at depth greater than 3 cm. The mean dose differences (±1SD) were −8%± 16%, −3%± 15%, −16%± 18%, and −9%± 16% for measurements vs AAA calculations and −10%± 14%, −5%± 12%, −19%± 17%, and −13%± 14% for Acuros-XB, for 6X, 6 flattening-filter free (FFF), 10X, and 10FFF beams, respectively. The same figures for dose differences relative to the open beam central axis dose were: −0.1%± 0.3%, 0.0%± 0.4%, −0.3%± 0.3%, and −0.1%± 0.3% for AAA and −0.2%± 0.4%, −0.1%± 0.4%, −0.5%± 0.5%, and −0.3%± 0.4% for Acuros-XB. Buildup dose was overestimated with AAA, while Acuros-XB gave

  9. Evaluation of radiation dose during the percutaneous angioplasty for arteriovenous shunt assembling

    International Nuclear Information System (INIS)

    Ting, Chien-Yi; Wu, Wen-Shiann; Tang, Kuo-Ting; Wang, Hsin-Ell; Lin, Chun-Chih

    2017-01-01

    Percutaneous angioplasty (PTA) for dysfunctional hemodialysis is usually performed by radiologists, but not cardiologists, in Taiwan, so that the radiation dose in patients and physicians are usually unknown and related studies are rare. In this study, we are pioneering an investigation into the radiation dose in percutaneous angioplasty for arteriovenous shunt assembling and the effect of RADPAD device, a lead-free surgical drape containing Bi and Ba, on the decrease of a radiation dose in the non-targeted organs of the patient and also the operator. The radiation dose in a typical digital subtraction angiography (DSA) by the PTA protocol under a fixed field of view (FOV), was measured with optically simulated luminescent dosimeters arranged in a PIXY RS-102 anthropomorphic phantom. The results indicate that there is a significant dose reduction at the hands (0.022±0.002 mGy before treatment vs. 0.014±0.001 mGy after treatment; P=0.021), but not at the lens (0.027±0.003 mGy before treatment vs. 0.018±0.001 mGy after treatment; P=0.058), and the gonads (0.026±0.003 mGy before treatment vs. 0.020±0.001 mGy after treatment; P=0.058), of the cardiologist/operator after treatment with the RADPAD drape. At the patient's abdomen, the dose significantly decreased from 1.597±0.104 mGy to 0.031±0.002 mGy (P<0.001) after treated with the RADPAD shield. For the chest, lens and thyroid in the patient, the doses were respectively 0.154±0.100 mGy (compared to 0.049±0.001 mGy after treated with the RADPAD drape; P=0.0002), 0.066±0.001 mGy (compared to 0.021±0.001 mGy after the RADPAD treatment; P=0.009), and 0.208±0.002 mGy (compared to 0.042±0.003 mGy after shielded with the RADPAD drape; P<0.0001), which represents an apparent reduction in dose. However, no significant difference was found in the dose-area product between before (179.9±0.1mGy.cm 2 ) and after (177.4±0.1mGy.cm 2 ) the treatment (P=0.38). In conclusion, the RADPAD drape significantly reduced

  10. Annual effective dose due to residential radon progeny in Sweden: Evaluations based on current risk projections models and on risk estimates from a nation-wide Swedish epidemiological study

    Energy Technology Data Exchange (ETDEWEB)

    Doi, M [National Inst. of Radiological Sciences, Chiba (Japan); Lagarde, F [Karolinska Inst., Stockholm (Sweden). Inst. of Environmental Medicine; Falk, R; Swedjemark, G A [Swedish Radiation Protection Inst., Stockholm (Sweden)

    1996-12-01

    Effective dose per unit radon progeny exposure to Swedish population in 1992 is estimated by the risk projection model based on the Swedish epidemiological study of radon and lung cancer. The resulting values range from 1.29 - 3.00 mSv/WLM and 2.58 - 5.99 mSv/WLM, respectively. Assuming a radon concentration of 100 Bq/m{sup 3}, an equilibrium factor of 0.4 and an occupancy factor of 0.6 in Swedish houses, the annual effective dose for the Swedish population is estimated to be 0.43 - 1.98 mSv/year, which should be compared to the value of 1.9 mSv/year, according to the UNSCEAR 1993 report. 27 refs, tabs, figs.

  11. Annual effective dose due to residential radon progeny in Sweden: Evaluations based on current risk projections models and on risk estimates from a nation-wide Swedish epidemiological study

    International Nuclear Information System (INIS)

    Doi, M.; Lagarde, F.

    1996-12-01

    Effective dose per unit radon progeny exposure to Swedish population in 1992 is estimated by the risk projection model based on the Swedish epidemiological study of radon and lung cancer. The resulting values range from 1.29 - 3.00 mSv/WLM and 2.58 - 5.99 mSv/WLM, respectively. Assuming a radon concentration of 100 Bq/m 3 , an equilibrium factor of 0.4 and an occupancy factor of 0.6 in Swedish houses, the annual effective dose for the Swedish population is estimated to be 0.43 - 1.98 mSv/year, which should be compared to the value of 1.9 mSv/year, according to the UNSCEAR 1993 report. 27 refs, tabs, figs

  12. Evaluation of image quality and dose in renal colic: comparison of different spiral-CT protocols

    International Nuclear Information System (INIS)

    Rimondini, A.; Mucelli, R.P.; Dalla Palma, L.; De Denaro, M.; Bregant, P.

    2001-01-01

    The aim of this study was to test different technical spiral-CT parameters to obtain optimal image quality with reduced X-ray dose. Images were acquired with a spiral-CT system Philips Tomoscan AVE1, using 250 mA, 120 kV, and 1-s rotational time. Three protocols were tested: protocol A with 5-mm thickness, pitch 1.6, slice reconstruction every 2.5 mm; protocol B with 3-mm thickness, pitch 1.6, slice reconstruction every 1.5 mm; and protocol C with 3-mm thickness, pitch 2, slice reconstruction every 1.5 mm. Two phantoms were employed to evaluate the image quality. Axial images were acquired, then sagittal and coronal images were reconstructed. Finally, the absorbed X-ray dose for each protocol was measured. Regarding image quality, 5-mm-thick images (protocol A) showed greater spatial resolution and lower noise compared with 3-mm-thick images (protocols B and C) on the axial plane; 3-mm reconstructed sagittal and coronal images (protocols B and C) showed an improved image quality compared with 5-mm reformatted images (protocol A). Concerning X-ray dose, the mean dose was: protocol A 19.6±0.8 mGy; protocol B 14.4±0.6 mGy; protocol C 12.5±1.0 mGy. Our study supports the use of thin slices (3 mm) combined with pitch of 1.6 or 2 in renal colic for X-ray dose reduction to the patient and good image quality. (orig.)

  13. [Evaluation of Dose Reduction of the Active Collimator in Multi Detector Row CT].

    Science.gov (United States)

    Ueno, Hiroyuki; Matsubara, Kosuke

    The purpose of this study was to evaluate the performance of active collimator by changing acquisition parameters and obtaining dose profiles in z-axis direction. Dose profiles along z-axis were obtained using XRQA2 Gafchromic film. As a result, the active collimator reduced overranging about 55% compared to that without the active collimator. In addition, by changing the combination of X-ray beam width (32 mm, 40 mm), pitch factor (1.4, 0.6), and the X-ray tube rotation time (0.5 s/rot, 1.0 s/rot), the overranging changed from 19.4 to 34.9 mm. Although the active collimator is effective for reducing overranging, it is necessary to adjust acquisition parameters by taking the properties of the active collimator for acquisition parameters, especially setting beam width, into consideration.

  14. Evaluation of low-dose irradiation on microbiological quality of white carrots and string beans

    International Nuclear Information System (INIS)

    Koike, Amanda C.R.; Santillo, Amanda G.; Rodrigues, Flávio T.; Duarte, Renato C.; Villavicencio, Anna Lucia C.H.

    2012-01-01

    The minimally processed food provided the consumer with a product quality, safety and practicality. However, minimal processing of food does not reduce pathogenic population of microorganisms to safe levels. Ionizing radiation used in low doses is effective to maintain the quality of food, reducing the microbiological load but rather compromising the nutritional values and sensory property. The association of minimal processing with irradiation could improve the quality and safety of product. The purpose of this study was to evaluate the effectiveness of low-doses of ionizing radiation on the reduction of microorganisms in minimally processed foods. The results show that the ionizing radiation of minimally processed vegetables could decontaminate them without several changes in its properties.

  15. Evaluation of low-dose irradiation on microbiological quality of white carrots and string beans

    Science.gov (United States)

    Koike, Amanda C. R.; Santillo, Amanda G.; Rodrigues, Flávio T.; Duarte, Renato C.; Villavicencio, Anna Lucia C. H.

    2012-08-01

    The minimally processed food provided the consumer with a product quality, safety and practicality. However, minimal processing of food does not reduce pathogenic population of microorganisms to safe levels. Ionizing radiation used in low doses is effective to maintain the quality of food, reducing the microbiological load but rather compromising the nutritional values and sensory property. The association of minimal processing with irradiation could improve the quality and safety of product. The purpose of this study was to evaluate the effectiveness of low-doses of ionizing radiation on the reduction of microorganisms in minimally processed foods. The results show that the ionizing radiation of minimally processed vegetables could decontaminate them without several changes in its properties.

  16. Evaluation of surface and shallow depth dose reductions using a Superflab bolus during conventional and advanced external beam radiotherapy.

    Science.gov (United States)

    Yoon, Jihyung; Xie, Yibo; Zhang, Rui

    2018-03-01

    The purpose of this study was to evaluate a methodology to reduce scatter and leakage radiations to patients' surface and shallow depths during conventional and advanced external beam radiotherapy. Superflab boluses of different thicknesses were placed on top of a stack of solid water phantoms, and the bolus effect on surface and shallow depth doses for both open and intensity-modulated radiotherapy (IMRT) beams was evaluated using thermoluminescent dosimeters and ion chamber measurements. Contralateral breast dose reduction caused by the bolus was evaluated by delivering clinical postmastectomy radiotherapy (PMRT) plans to an anthropomorphic phantom. For the solid water phantom measurements, surface dose reduction caused by the Superflab bolus was achieved only in out-of-field area and on the incident side of the beam, and the dose reduction increased with bolus thickness. The dose reduction caused by the bolus was more significant at closer distances from the beam. Most of the dose reductions occurred in the first 2-cm depth and stopped at 4-cm depth. For clinical PMRT treatment plans, surface dose reductions using a 1-cm Superflab bolus were up to 31% and 62% for volumetric-modulated arc therapy and 4-field IMRT, respectively, but there was no dose reduction for Tomotherapy. A Superflab bolus can be used to reduce surface and shallow depth doses during external beam radiotherapy when it is placed out of the beam and on the incident side of the beam. Although we only validated this dose reduction strategy for PMRT treatments, it is applicable to any external beam radiotherapy and can potentially reduce patients' risk of developing radiation-induced side effects. © 2018 The Authors. Journal of Applied Clinical Medical Physics published by Wiley Periodicals, Inc. on behalf of American Association of Physicists in Medicine.

  17. Evaluation of dose conversion coefficients for external exposure using Taiwanese reference man and woman

    International Nuclear Information System (INIS)

    Chang, S.J.; Hung, S.Y.; Liu, Y.L.; Jiang, S.H.; Wu, J.

    2015-01-01

    Reference man has been widely used for external and internal dose evaluation of radiation protection. The parameters of the mathematical model of organs suggested by the International Commission of Radiological Protection (ICRP) are adopted from the average data of Caucasians. However, the organ masses of Asians are significantly different from the data of Caucasians, leading to potentially dosimetric errors. In this study, a total of 40 volunteers whose heights and weights corresponded to the statistical average of Taiwanese adults were recruited. Magnetic resonance imaging was performed, and T2-weighted images were acquired. The Taiwanese reference man and woman were constructed according to the measured organ masses. The dose conversion coefficients (DCFs) for anterior-posterior (AP), posterior-anterior (PA), right lateral (RLAT) and left lateral (LLAT) irradiation geometries were simulated. For the Taiwanese reference man, the average differences of the DCFs compared with the results of ICRP-74 were 7.6, 5.1 and 11.1 % for 0.1, 1 and 10 MeV photons irradiated in the AP direction. The maximum difference reached 51.7 % for the testes irradiated by 10 MeV photons. The size of the trunk, the volume and the geometric position of organs can cause a significant impact on the DCFs for external exposure of radiation. The constructed Taiwanese reference man and woman can be used in radiation protection to increase the accuracy of dose evaluation for the Taiwanese population. (authors)

  18. Systems engineering approach for the reuse of metallic waste from NPP decommissioning and dose evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Hyung Woo; Kim, Chang Lak [KEPCO International Nuclear Graduate School, Ulsan (Korea, Republic of)

    2017-03-15

    The oldest commercial reactor in South Korea, Kori-1 Nuclear Power Plant (NPP), will be shut down in 2017. Proper treatment for decommissioning wastes is one of the key factors to decommission a plant successfully. Particularly important is the recycling of clearance level or very low level radioactively contaminated metallic wastes, which contributes to waste minimization and the reduction of disposal volume. The aim of this study is to introduce a conceptual design of a recycle system and to evaluate the doses incurred through defined work flows. The various architecture diagrams were organized to define operational procedures and tasks. Potential exposure scenarios were selected in accordance with the recycle system, and the doses were evaluated with the RESRAD-RECYCLE computer code. By using this tool, the important scenarios and radionuclides as well as impacts of radionuclide characteristics and partitioning factors are analyzed. Moreover, dose analysis can be used to provide information on the necessary decontamination, radiation protection process, and allowable concentration limits for exposure scenarios.

  19. 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.

  20. Dose and risk evaluation in digital mammography using computer modeling

    International Nuclear Information System (INIS)

    Correa, Samanda Cristine Arruda; Souza, Edmilson Monteiro de; Silva, Humberto de Oliveira; Silva, Ademir Xavier da; Lopes, Ricardo Tadeu; Magalhaes, Sarah Braga

    2010-01-01

    Digital mammography has been introduced in several countries in the last years. The new technology requires new optimising methods considering for instance the increased possibility of changing the absorbed dose, mainly in modern mammographic systems that allow the operator to choose the beam quality by varying the tube voltage, and filter and target materials. In this work, the Monte Carlo code MCNPX is used in order to investigate how the average glandular dose vary with tube voltage (23-32 kV) and anode-filter combination (Mo-Mo,Mo-Rh and Rh-Rh) in digital mammographic examinations. Furthermore, the risk of breast cancer incidence attributable to mammography exams was estimated using the Biological Effects of Ionizing Radiations (BEIR) VII Committee Report. The results show that the risk of breast cancer incidence in women younger than 30 years of age tends to decrease significantly using Rh-Rh anode-filter combination and higher tube voltage. For women older than 50 years of age the variation of tube voltage, and anode-filter combination did not influence the risk values considerably. (author)

  1. Dose and risk evaluation in digital mammography using computer modeling

    Energy Technology Data Exchange (ETDEWEB)

    Correa, Samanda Cristine Arruda; Souza, Edmilson Monteiro de, E-mail: scorrea@nuclear.ufrj.b, E-mail: emonteiro@nuclear.ufrj.b [Centro Universitario Estadual da Zona Oeste (CCMAT/UEZO), Rio de Janeiro, RJ (Brazil); Silva, Humberto de Oliveira, E-mail: hbetorj@gmail.co [Universidade Federal do Rio de Janeiro IF/UFRJ, RJ (Brazil). Inst. de Fisica; Silva, Ademir Xavier da; Lopes, Ricardo Tadeu; Magalhaes, Sarah Braga, E-mail: ademir@nuclear.ufrj.b, E-mail: ricardo@lin.ufrj.b, E-mail: smagalhaes@nuclear.ufrj.b [Coordenacao dos Programas de Pos-Graduacao de Engenharia (COPPE/UFRJ), RJ (Brazil). Programa de Engenharia Nuclear

    2010-07-01

    Digital mammography has been introduced in several countries in the last years. The new technology requires new optimising methods considering for instance the increased possibility of changing the absorbed dose, mainly in modern mammographic systems that allow the operator to choose the beam quality by varying the tube voltage, and filter and target materials. In this work, the Monte Carlo code MCNPX is used in order to investigate how the average glandular dose vary with tube voltage (23-32 kV) and anode-filter combination (Mo-Mo,Mo-Rh and Rh-Rh) in digital mammographic examinations. Furthermore, the risk of breast cancer incidence attributable to mammography exams was estimated using the Biological Effects of Ionizing Radiations (BEIR) VII Committee Report. The results show that the risk of breast cancer incidence in women younger than 30 years of age tends to decrease significantly using Rh-Rh anode-filter combination and higher tube voltage. For women older than 50 years of age the variation of tube voltage, and anode-filter combination did not influence the risk values considerably. (author)

  2. Dosimetric Evaluation of High-Dose-Rate Interstitial Brachytherapy Boost Treatments for Localized Prostate Cancer

    International Nuclear Information System (INIS)

    Froehlich, Georgina; Agoston, Peter; Loevey, Jozsef; Somogyi, Andras; Fodor, Janos; Polgar, Csaba; Major, Tibor

    2010-01-01

    Purpose: to quantitatively evaluate the dose distributions of high-dose-rate (HDR) prostate implants regarding target coverage, dose homogeneity, and dose to organs at risk. Material and methods: treatment plans of 174 implants were evaluated using cumulative dose-volume histograms (DVHs). The planning was based on transrectal ultrasound (US) imaging, and the prescribed dose (100%) was 10 Gy. The tolerance doses to rectum and urethra were 80% and 120%, respectively. Dose-volume parameters for target (V90, V100, V150, V200, D90, D min ) and quality indices (DNR [dose nonuniformity ratio], DHI [dose homogeneity index], CI [coverage index], COIN [conformal index]) were calculated. Maximum dose in reference points of rectum (D r ) and urethra (D u ), dose to volume of 2 cm 3 of the rectum (D 2ccm ), and 0.1 cm 3 and 1% of the urethra (D 0.1ccm and D1) were determined. Nonparametric correlation analysis was performed between these parameters. Results: the median number of needles was 16, the mean prostate volume (V p ) was 27.1 cm 3 . The mean V90, V100, V150, and V200 were 90%, 97%, 39% and 13%, respectively. The mean D90 was 109%, and the D min was 87%. The mean doses in rectum and urethra reference points were 75% and 119%, respectively. The mean volumetric doses were D 2ccm = 49% for the rectum, D 0.1ccm = 126%, and D1 = 140% for the urethra. The mean DNR was 0.37, while the DHI was 0.60. The mean COIN was 0.66. The Spearman rank order correlation coefficients for volume doses to rectum and urethra were R(D r , D 2ccm ) = 0.69, R(D u , D 0.1ccm ) = 0.64, R(D u , D1) = 0.23. Conclusion: US-based treatment plans for HDR prostate implants based on the real positions of catheters provided acceptable dose distributions. In the majority of the cases, the doses to urethra and rectum were kept below the defined tolerance levels. For rectum, the dose in reference points correlated well with dose-volume parameters. For urethra dose characterization, the use of D1 volumetric

  3. Dosimetric Evaluation of High-Dose-Rate Interstitial Brachytherapy Boost Treatments for Localized Prostate Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Froehlich, Georgina [Semmelweis Univ., Budapest (Hungary); Dept. of Radiotherapy, National Inst. of Oncology, Budapest (Hungary); Agoston, Peter; Loevey, Jozsef; Somogyi, Andras; Fodor, Janos; Polgar, Csaba; Major, Tibor [Dept. of Radiotherapy, National Inst. of Oncology, Budapest (Hungary)

    2010-07-15

    Purpose: to quantitatively evaluate the dose distributions of high-dose-rate (HDR) prostate implants regarding target coverage, dose homogeneity, and dose to organs at risk. Material and methods: treatment plans of 174 implants were evaluated using cumulative dose-volume histograms (DVHs). The planning was based on transrectal ultrasound (US) imaging, and the prescribed dose (100%) was 10 Gy. The tolerance doses to rectum and urethra were 80% and 120%, respectively. Dose-volume parameters for target (V90, V100, V150, V200, D90, D{sub min}) and quality indices (DNR [dose nonuniformity ratio], DHI [dose homogeneity index], CI [coverage index], COIN [conformal index]) were calculated. Maximum dose in reference points of rectum (D{sub r}) and urethra (D{sub u}), dose to volume of 2 cm{sup 3} of the rectum (D{sub 2ccm}), and 0.1 cm{sup 3} and 1% of the urethra (D{sub 0.1ccm} and D1) were determined. Nonparametric correlation analysis was performed between these parameters. Results: the median number of needles was 16, the mean prostate volume (V{sub p}) was 27.1 cm{sup 3}. The mean V90, V100, V150, and V200 were 90%, 97%, 39% and 13%, respectively. The mean D90 was 109%, and the D{sub min} was 87%. The mean doses in rectum and urethra reference points were 75% and 119%, respectively. The mean volumetric doses were D{sub 2ccm} = 49% for the rectum, D{sub 0.1ccm} = 126%, and D1 = 140% for the urethra. The mean DNR was 0.37, while the DHI was 0.60. The mean COIN was 0.66. The Spearman rank order correlation coefficients for volume doses to rectum and urethra were R(D{sub r}, D{sub 2ccm}) = 0.69, R(D{sub u}, D{sub 0.1ccm}) = 0.64, R(D{sub u}, D1) = 0.23. Conclusion: US-based treatment plans for HDR prostate implants based on the real positions of catheters provided acceptable dose distributions. In the majority of the cases, the doses to urethra and rectum were kept below the defined tolerance levels. For rectum, the dose in reference points correlated well with dose

  4. Dosimetric evaluation of high-dose-rate interstitial brachytherapy boost treatments for localized prostate cancer.

    Science.gov (United States)

    Fröhlich, Georgina; Agoston, Péter; Lövey, József; Somogyi, András; Fodor, János; Polgár, Csaba; Major, Tibor

    2010-07-01

    To quantitatively evaluate the dose distributions of high-dose-rate (HDR) prostate implants regarding target coverage, dose homogeneity, and dose to organs at risk. Treatment plans of 174 implants were evaluated using cumulative dose-volume histograms (DVHs). The planning was based on transrectal ultrasound (US) imaging, and the prescribed dose (100%) was 10 Gy. The tolerance doses to rectum and urethra were 80% and 120%, respectively. Dose-volume parameters for target (V90, V100, V150, V200, D90, D(min)) and quality indices (DNR [dose nonuniformity ratio], DHI [dose homogeneity index], CI [coverage index], COIN [conformal index]) were calculated. Maximum dose in reference points of rectum (D(r)) and urethra (D(u)), dose to volume of 2 cm(3) of the rectum (D(2ccm)), and 0.1 cm(3) and 1% of the urethra (D(0.1ccm) and D1) were determined. Nonparametric correlation analysis was performed between these parameters. The median number of needles was 16, the mean prostate volume (V(p)) was 27.1 cm(3). The mean V90, V100, V150, and V200 were 99%, 97%, 39%, and 13%, respectively. The mean D90 was 109%, and the D(min) was 87%. The mean doses in rectum and urethra reference points were 75% and 119%, respectively. The mean volumetric doses were D(2ccm) = 49% for the rectum, D(0.1ccm) = 126%, and D1 = 140% for the urethra. The mean DNR was 0.37, while the DHI was 0.60. The mean COIN was 0.66. The Spearman rank order correlation coefficients for volume doses to rectum and urethra were R(D(r),D(2ccm)) = 0.69, R(D(u),D0.(1ccm)) = 0.64, R(D(u),D1) = 0.23. US-based treatment plans for HDR prostate implants based on the real positions of catheters provided acceptable dose distributions. In the majority of the cases, the doses to urethra and rectum were kept below the defined tolerance levels. For rectum, the dose in reference points correlated well with dose-volume parameters. For urethra dose characterization, the use of D1 volumetric parameter is recommended.

  5. Evaluation of the Accuracy of Polymer Gels for Determining Electron Dose Distributions in the Presence of Small Heterogeneities.

    Science.gov (United States)

    Asl, R Ghahraman; Nedaie, H A; Banaee, N

    2017-12-01

    The aim of this study is to evaluate the application and accuracy of polymer gels for determining electron dose distributions in the presence of small heterogeneities made of bone and air. Different cylindrical phantoms containing MAGIC (Methacrylic and Ascorbic acid in Gelatin Initiated by Copper) normoxic polymer gel were used under the slab phantoms during irradiation. MR images of the irradiated gel phantoms were obtained to determine their R2 (spin-spin) relaxation maps for conversion to absorbed dose. One- and 2-dimensional lateral dose profiles were acquired at depths of 1 and 4 cm for 8 and 15 MeV electron beams. The results were compared with the doses measured by a diode detector at the same positions. In addition, the dose distribution in the axial orientation was measured by the gel dosimeter. The slope and intercept for the R2 versus dose curve were 0.509 ± 0.002 Gy s and 4.581 ± 0.005 s, respectively. No significant variation in dose-R2 response was seen for the two electron energies within the applied dose ranges. The mean dose difference between the measured gel dose profiles was smaller than 3% compared to those measured by the diode detector. These results provide further demonstration that electron dose distributions are significantly altered in the presence of tissue inhomogeneities such as bone and air cavity and that MAGIC gel is a useful tool for 3-dimensional dose visualization and qualitative assessment of tissue inhomogeneity effects in electron beam dosimetry.

  6. Dose evaluation due to the effluent liberation by medical installations at city of Rio de Janeiro, Brazil

    International Nuclear Information System (INIS)

    Shu, Jane; Rochedo, Elaine R.R.; Heilbron, Paulo F.L.; Crispim, Verginia R.

    2011-01-01

    This paper, the city of Rio de Janeiro was taken as a case study. It was processed deterministic and probabilistic simulations vor evaluation of the dose in two exposure sceneries, one of them referring to public members exposure and the other relative to exposure of sewage sanitary treatment plant workers. The results showed that at present the doses for inhabitants of the city and operators of treatment station are lower to dose limit established for the public, the approach presently in use in Brazil is not sufficient to accomplish whit international requirements and the regulation should be revised to be adopted specific values for each radionuclide

  7. Dose finding study of granisetron in patients receiving high-dose cisplatin chemotherapy. The Granisetron Study Group.

    Science.gov (United States)

    Riviere, A.

    1994-01-01

    The efficacy and safety of three different doses of granisetron (2 micrograms kg-1, group A; 10 micrograms kg-1, group B; 40 micrograms kg-1, group C) were compared in a randomised, double-blind study of 157 patients due to receive high-dose cisplatin therapy (mean dose > 97 mg m-2). In each group, up to two 3 mg rescue doses of granisetron were allowed if more than mild nausea or vomiting occurred. In group A 30.8%, in group B 61.5% and in group C 67.9% of patients were complete responders (i.e. no vomiting or nothing worse than mild nausea) during the first 24 h. These differences are significant between groups A and B, and A and C. There were no statistically significant differences in any efficacy variable between the 10 micrograms kg-1 and 40 micrograms kg-1 groups, although in each case the trend favoured the higher dose. Additional rescue doses resulted in resolved or improved symptoms in 95.3% for the first rescue dose and 93.3% for the second. Over the 7 days of the study, 82.7%, 82.7% and 86.8% of patients in groups A, B and C respectively were treated with granisetron alone. Headache was the most common side-effect, reported by 9.6% of patients; the majority of headaches were mild. There was no difference between the treatment groups regarding the adverse event rate. We concluded that prophylactic doses of 10 or 40 micrograms kg-1 lead to a safe and satisfactory degree of control of nausea and vomiting induced by high-dose cisplatin. PMID:8180032

  8. Monte Carlo simulation study on dose enhancement by gold nanoparticles in brachytherapy

    International Nuclear Information System (INIS)

    Cho, Sungkoo; Jeong, Jonghwi; Kim, Chanhyeong; Yoon, Myonggeun

    2010-01-01

    Radiation dose enhancement by injection of a high atomic number (Z) material into tumor volumes has been studied for various radiation sources and different concentrations of gold nanoparticles. Brachytherapy employs low energy photons of less than ∼0.5 MeV, which indeed is the optimal energy range for radiation dose enhancement by introduction of high-Z material. The present study uses the MCNPX TM code to estimate the dose enhancement by gold nanoparticles for the four common brachytherapy sources ( 137 Cs, 192 Ir, 125 I, and 103 Pd). Additionally, cisplatin (H 6 Cl 2 N 2 Pt), a platinum-based chemotherapeutic drug, was used to evaluate the dose enhancement. The simulated source models were evaluated with reference to the calculated TG-43 parameter values. The dose enhancement in the tumor region due to the gold nanoparticles and cisplatin was evaluated according to the dose enhancement factor (DEF). The maximum values of the average DEFs were found to be 1.03, 1.11, 3.43, and 2.17 for the 137 Cs, 192 Ir, 125 I, and 103 Pd sources, respectively. The dose enhancement values for the low-energy sources were significantly higher than those for the high-energy sources. The dose enhancement due to cisplatin was calculated by using the same approach and was found to be comparable to that of the gold nanoparticles. The maximum value of the average DEF for cisplatin was 1.12 for the 5% concentration level in water and a 192 Ir source. We confirmed that cisplatin could be applied to cancer therapy that combines chemotherapeutic drugs with radiation therapy. The results presented herein will be used to study dose enhancement in tumor regions using various radiation modalities with high atomic number materials.

  9. Occupational dose measurement in interventional cardiology, dosimetry comparison study

    International Nuclear Information System (INIS)

    Ahmad, A.M.A.

    2008-05-01

    The number of cardiology interventional procedures has significantly increased recently. This is due to the reliability of the diagnostic equipment to diagnose many heart disease. In the procedures the x-ray used results in increasing radiation doses to the staff. The cardiologists and other staff members in interventional cardiology are usually working close to the area under examination and receive the dose primarily from scattered radiation from the patient. Therefore workers in interventional cardiology are expected to receive high doses. This study overviews the status of occupational exposure at the three cardiology centers at three different hospitals in Khartoum compared with that received by workers at other medical practices (radiotherapy, nuclear medicine and diagnostic radiology) in the Institute of Nuclear and Technology (INMO) at El Gezira. The TLD Harshaw 6600 reader was used in the assessment of effective dose for Hp (10). Two TLDs were used by each worker at the three cardiology centres, one worn under a protective apron and the other worn outside and above the apron as specified by the ICRP. Each worker at the other sections was facilitated with one dosimeter to be worn on the chest. The annual doses received by 14 cardiologists, 13 nurses and 9 technologists at the three cardiology centres were in the range: (0.84-4.77), (0.15-2.08), (0.32-1.10) mSv respectively. In the INMO the annual doses received by 7 doctors, 5 nurses and 14 technologists were in the range: (0.12-0.51), (0.11-0.65), (0.03-1.39) mSv respectively. The results showed that the annual doses received by the workers do not exceed 20 mSv. The study also indicated that doses received by workers in interventional cardiology, in particular the cardiologists are high compared to that received at the other medical sections.(Author)

  10. CT for evaluation of potential renal donors – How does iterative reconstruction influence image quality and dose?

    Energy Technology Data Exchange (ETDEWEB)

    Kahn, Johannes, E-mail: johannes.kahn@charite.de [Department of Radiology, Charité, Charitéplatz 1, 10117 Berlin (Germany); Grupp, Ulrich, E-mail: ulrich.grupp@charite.de [Department of Radiology, Charité, Charitéplatz 1, 10117 Berlin (Germany); Rotzinger, Roman, E-mail: roman.rotzinger@charite.de [Department of Radiology, Charité, Charitéplatz 1, 10117 Berlin (Germany); Kaul, David, E-mail: david.kaul@charite.de [Department of Radiooncology and Radiotherapy, Charité, Charitéplatz 1, 10117 Berlin (Germany); Schäfer, Max-Ludwig, E-mail: max-ludwig.schaefer@charite.de [Department of Radiology, Charité, Charitéplatz 1, 10117 Berlin (Germany); Streitparth, Florian, E-mail: florian.streitparth@charite.de [Department of Radiology, Charité, Charitéplatz 1, 10117 Berlin (Germany)

    2014-08-15

    Purpose: To assess ASIR (adaptive statistical iterative reconstruction) technique regarding dose reduction and its impact on image quality in evaluation CTs of potential kidney donors. Materials and methods: Between May and November 2013, a prospective study of 53 assumingly healthy potential kidney donors was conducted. The subjects underwent abdominal evaluation CT prior to the planned explantation of a kidney and were randomly divided into 2 groups: Group A was examined with an ASIR 40 protocol (n = 26), group B (n = 27) was examined using a standard FBP (filtered back projection) protocol. Image quality was assessed both quantitatively (by obtaining attenuation values in different organ regions and calculating SNR and CNRs) and qualitatively (by two observers who evaluated image quality using a 5-point scale system). Applied dose was analyzed as CTDIvol (mGy), total DLP (mGy × cm) and effective dose (mSv). Results: Applied dose in group A was about 26% lower than in group B (p < 0.05). Between both groups, dose determining parameters such as scan length and patients’ body diameter showed no significant difference. SNR (signal-to-noise ratio) was significantly higher in group A (p < 0.05). CNRs (contrast-to-noise ratios) for different tissues were not significantly different. Observer rated image quality showed no significant difference. Conclusion: ASIR can contribute to a relevant dose reduction without any loss of image quality in CT scans for evaluating potential kidney donors.

  11. EVALUATION OF EYE LENS DOSE TO WORKERS IN THE STEAM GENERATOR AT THE KOREAN OPTIMIZED POWER REACTOR 1000.

    Science.gov (United States)

    Maeng, Sung Jun; Kim, Jinhwan; Cho, Gyuseong

    2018-03-15

    ICRP (2011) revised the dose limit to the eye lens to 20 mSv/y based on a recent epidemiological study of radiation-induced cataracts. Maintenance of steam generators at nuclear power plants is one of the highest radiation-associated tasks within a non-uniform radiation field. This study aims to evaluate eye lens doses in the steam generators of the Korean OPR1000 design. The source term was characterized based on the CRUD-specific activity, and both the eye lens dose and organ dose were simulated using MCNP6 combined with an ICRP voxel phantom and a mesh phantom, respectively. The eye lens dose was determined to be 5.39E-02-9.43E-02 Sv/h, with a negligible effect by beta particles. As the effective dose was found to be 0.81-1.21 times the lens equivalent dose depending on the phantom angles, the former can be used to estimate the lens dose in the SG of the OPR1000 for radiation monitoring purposes.

  12. Evaluation of energy responses for neutron dose-equivalent meters made in Japan

    International Nuclear Information System (INIS)

    Saegusa, J.; Yoshizawa, M.; Tanimura, Y.; Yoshida, M.; Yamano, T.; Nakaoka, H.

    2004-01-01

    Energy responses of three types of Japanese neutron dose-equivalent (DE) meters were evaluated by Monte Carlo simulations and measurements. The energy responses were evaluated for thermal neutrons, monoenergetic neutrons with energies up to 15.2 MeV, and also for neutrons from such radionuclide sources as 252 Cf and 241 Am-Be. The calculated results were corroborated with the measured ones. The angular dependence of the response and the DE response were also evaluated. As a result, reliable energy responses were obtained by careful simulations of the proportional counter, moderator and absorber of the DE meters. Furthermore, the relationship between pressure of counting gas and response of the DE meter was discussed. By using the obtained responses, relations between predicted readings of the DE meters and true DE values were studied for various workplace spectra

  13. Analytical evaluation of dose measurement of critical accident at SILENE (Contract research)

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, Takemi; Tonoike, Kotaro; Miyoshi, Yoshinori [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2003-03-01

    Institute for Radioprotection and Nuclear Safety (IRSN) and the OECD Nuclear Energy Agency (NEA) jointly organized SILENE Accident Dosimetry Intercomparison Exercise to intercompare the dose measurement systems of participating countries. Each participating country carried out dose measurements in the same irradiation field, and the measurement results were mutually compared. The authors participated in the exercise to measure the doses of gamma rays and neutron from SILENE by using thermoluminescence dosimeters (TLD's) and an alanine dosimeter. In this examination, the authors derived evaluation formulae for obtaining a tissue-absorbed dose from measured value (ambient dose equivalent) of TLD for neutron. We reported the tissue-absorbed dose computed using this evaluation formula to OECD/NEA. TLD's for neutron were irradiated in the TRACY facility to verify the evaluation formulae. The results of TLD's were compared with the calculations of MCNP and measurements with alanine dose meter. We found that the ratio of the dose by the evaluation formula to the measured value by the alanine dosimeter was 0.94 and the formula agreed within 6%. From examination of this TRACY, we can conclude that the value reported to OECD/NEA has equivalent accuracy. (author)

  14. Video dosimetry: evaluation of X-radiation dose by video fluoroscopic image

    International Nuclear Information System (INIS)

    Nova, Joao Luiz Leocadio da; Lopes, Ricardo Tadeu

    1996-01-01

    A new methodology to evaluate the entrance surface dose on patients under radiodiagnosis is presented. A phantom is used in video fluoroscopic procedures in on line video signal system. The images are obtained from a Siemens Polymat 50 and are digitalized. The results show that the entrance surface dose can be obtained in real time from video imaging

  15. Better management of wheat allergy using a very low-dose food challenge: A retrospective study.

    Science.gov (United States)

    Okada, Yu; Yanagida, Noriyuki; Sato, Sakura; Ebisawa, Motohiro

    2016-01-01

    Low-dose reactive wheat-allergic children are at a high risk of a positive oral food challenge (OFC). The present study aimed to evaluate whether the results of a very low-dose (VL) OFC would contribute to better wheat allergy management in this population. We retrospectively reviewed wheat-allergic subjects who underwent a VL OFC with 2 g of udon noodles (equivalent to 53 mg of wheat protein) and had a previous allergic reaction to management of some low-dose reactive wheat-allergic children from complete avoidance to partial wheat intake. Copyright © 2015 The Authors. Production and hosting by Elsevier B.V. All rights reserved.

  16. Mathematical phantoms for evaluation of age-specific internal dose

    International Nuclear Information System (INIS)

    Cristy, M.

    1980-01-01

    A series of mathematical phantoms representing children has been developed for use with photon transport codes. These phantoms, patterned after the Fisher-Snyder adult phantom, consist of simple mathematical expressions for the boundaries of the major organs and body sections. The location and shape of the organs are consistent with drawings depicting developmental anatomy, with the organ volumes assigned such that the masses at the various ages conform closely with the data presented in Reference Man. The explicit mathematical expressions for the various ages overcome the potential misrepresentation of organ sizes that occurred in phantoms derived from simple mathematical transformations of the adult phantom. Female breast tissue has been added to the phantoms, including the adult, now allowing assessment of doses to this organ

  17. Once-daily dosing of saquinavir and low-dose ritonavir in HIV-1-infected individuals: a pharmacokinetic pilot study

    NARCIS (Netherlands)

    van Heeswijk, R. P.; Veldkamp, A. I.; Mulder, J. W.; Meenhorst, P. L.; Lange, J. M.; Beijnen, J. H.; Hoetelmans, R. M.

    2000-01-01

    To investigate the steady-state pharmacokinetics of a once-daily dosing regimen of saquinavir soft gelatin capsules in combination with a low dose of ritonavir in HIV-1-infected individuals. Open-label, multi-dose, pharmacokinetic pilot study. Seven HIV-1-infected individuals who were treated with

  18. Optimisation of CT procedures by dose reduction in abdominal-pelvic studies of chronic patients

    International Nuclear Information System (INIS)

    Calvo, D.; Rodriguez, A.M.; Peinado, M.A.; Fernandez, B.; Fernandez, B.M.; Jimenez, J.R.

    2006-01-01

    Full text of publication follows: Objectives: CT explorations are responsible of a significant increase of collective dose during last twenty years. However, by adapting the procedures to the specific diagnostic requirements of each kind of exploration, dose values can be decreased. This can be specially interesting for chronic patients who undergo several CT controls. The aim of this research is to contrast CT image diagnostic quality by comparing those techniques commonly used in our hospital with lower dose ones. Materials and methods: In a first phase, a study on phantom has been developed to evaluate image quality variations obtained with standard a several low dose techniques. Dose reduction was quantified as well by means of C.T.D.I. w measurements on an abdominal phantom. Both aspects were taken into account to determine a dose threshold below image quality degradation was considered unacceptable from a diagnostic point of view. Subsequently, a group of 50 chronic patients under follow -up was selected to undergo a control CT but with a low dose-technique. Image diagnostic quality was compared with that of previous controls obtained using the standard technique. Three experimented radiologist carried out this evaluation over a sample of six particular slices located at the abdomen and pelvis using an ordinal scale. Such a scale gradate the confidence level of the image for each radiologist. This evaluation was repeated one and two months later without knowledge of previous results to calculate inter and intra -observer variability. Conclusions: CT studies can be carried out with a significant dose reduction preserving their diagnostic capabilities. A quantitative evaluation will be offered at the end of the study, still running. (authors)

  19. Evaluation of multiple scan average dose (MSAD) levels in computerized tomography in Minas Gerais state, Brazil

    International Nuclear Information System (INIS)

    Alonso, Thessa C.; Vieira, Leandro de A.; Barbosa, Nayra V.; Oliveira, Jeyselaine R. de; Cesar, Adriana C.Z.; Silva, Teogenes A. da

    2014-01-01

    Computed Tomography (CT) grows every year and is a diagnostic method that has revolutionized radiology with advances in procedures for obtaining image. However, the indiscriminate use of this method generates relatively high doses in patients. The diagnostic reference levels (DRLs) is a practical tool to promote the evaluation of existing protocols. The optimization and the periodic review of the protocols are important to balance the risk of radiation. The present study aims to conduct a survey of levels of MSAD of Minas Gerais following the procedures recommended by current Brazilian law. (author)

  20. Exposure dose evaluation of worker at radioactive waste incineration facility on KAERI

    International Nuclear Information System (INIS)

    Park, Sang Kyu; Jeon, Jong Seon; Kim, Youn Hwa; Lee, Jae Min; Lee, Gi Won

    2011-01-01

    An incineration treatment of inflammable radioactive wastes leads to have a reduction effect of disposal cost and also to contribute an enhancement of safety at a disposal site by taking the advantage of stabilization of the wastes which is accomplished by converting organic materials into inorganic materials. As it was required for an incineration technology, KAERI (Korea Atomic Energy Research Institute) has developed a pilot incineration process and then constructed a demonstration incineration facility having based on the operating experiences of the pilot process. In this study, worker exposure doses were evaluated to confirm safety of workers before the demonstration incineration facility will commence a commercial. (author)

  1. Evaluation of Radioactivity Concentration in Tilapia Nilotica and Radiation Dose to Egyptian Population

    Science.gov (United States)

    Amer, Hannan H.; El-Khawas, Enas H.

    2013-03-01

    One of the three goals of the United Nations for sustainable food security is to ensure that all people have access to sufficient, nutritionally adequate, and safe food. The study was carried out to evaluate the Uranium (238U) and thorium (232Th) concentration in the Bolti (Tilapia nilotica) fish collected from Nasser Lake by using two different types of detectors CR-39 SSNTDs and gamma spectroscopy. The annual intake of Bolti fish was estimated on the basis of their average annual consumption. Calculations were also made to determine the effective dose to an individual consuming such diet.

  2. Evaluation of Radioactivity Concentration In Tilapia Nilotica and Radiation Dose to Egyptian Population

    International Nuclear Information System (INIS)

    Amer, H.H.; Khawas, E.H.; Nabil, G.M.

    2011-01-01

    One of the three goals of the United Nations for sustainable food security is to ensure that all people have access to sufficient, nutritionally adequate and safe food. The study was carried out to evaluate the uranium ( 238 U) and thorium ( 232 Th) concentrations in the Bolti fish (Tilapia nilotica) collected from Naser Lake by using two different types of detectors CR-39 SSNTD and gamma spectroscopy. The annual intake of Bolti fish was estimated on the basis of their average annual consumption. Calculations were also made to determine the effective dose to an individual consuming such diet

  3. Development of PDRESS (Patient Specific Dose Real Evaluation Systems) using a TENOMAG Gel and Optical CT (VISTA) in Clinical IMRT Prostate Case

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Suk; Shim, Jang Bo; Chang, Kyung Hwan; Cao, Yuanjie; Yi, Jaeyoun; Park, Jinwoo; Cho, Sam Ju; Lee, Sang Hoon; Huh, HyunDo; Cho, Kwang Hwan; Min, Chul Kee; Yang, Dae Sik; Park, Young Je; Yoon, Won Seob; Kim, Chul Yong, E-mail: sukmp@korea.ac.k

    2010-11-01

    The aims of this study, we present the preliminary results of 3 dimensional dose evaluation software ({sup P}DRESS, patient specific dose real evaluation systems). In this work, we compared planned 3D dose distribution with measured 3D dose distribution using a novel normoxic polymer gel dosimeter (TENOMAG) and a commercial cone-beam optical CT scanner (VISTA{sup TM}, Modus Medical Devices, Inc., London, ON, Canada) to verify the 3D dose distribution in intensity-modulated radiation therapy (IMRT) prostate case. And we developed {sup P}DRESS using the Xelis Flatform which is developed by INFINITT Corporation is used to display the 3D dose distribution by loading the DICOM RT Data which is exported from RTP and optical-CT reconstructed VFF file. Data analysis is achieved by comparing the RTP data with the VFF data using profile, gamma map, and DTA. The profiles showed good agreement between RTP data, gel dosimeter, and gamma distribution and the precision of the dose distribution is within {+-} 5%. The results from this study show that there are no significantly discrepancies between the calculated dose distribution from treatment plan and the measured dose distribution from a TENOMAG gel scanned with an optical CT scanner. The 3D dose evaluation software ({sup P}DRESS) which is developed in this study evaluates the accuracy of the three dimensional dose distributions.

  4. Comparative study of dose descriptor in pediatric computed tomography exams

    International Nuclear Information System (INIS)

    Finatto, Jerusa Dalbosco; Silva, Ana Maria Marques da; Froner, Ana Paula Pastre; Pimentel, Juliana

    2014-01-01

    This work aims to investigate the dose descriptor, volumetric Computed Tomography Dose Index (CTDI), a pediatric patients sample undergoing to skull CT, comparing the results with the diagnostic reference levels of the literature. Were collected volumetric CTDI values of all skull CT exams performed retrospectively in children of 0-10 years of age in a period of 12 months in a large hospital size. Patients, in a total of 103, were divided into four groups, where the criterion of separation used was age, trying to use the same division used in international references dose descriptors. In all acquisitions we used the pediatric protocol and the Automatic Exposure Control (AEC) available on the equipment. The CDTI values, with and without the use of AEC for pediatric studies, were compared. There was a reduction of approximately 100% in the absorbed dose value due to the use of the AEC. From the data collected and analyzed in this work, it is concluded that the use of dose reduction systems is relevant, such as the Care Dose, to maintain volumetric CTDI values within the reference levels. Also it is important the observation of range of children age to the appropriate choice of parameters used in the test protocol. The values obtained are according to the diagnostic reference levels from the literature

  5. A systematic study on factors affecting patient dose, (1)

    International Nuclear Information System (INIS)

    Otsuka, Akiyoshi; Higashida, Yoshiharu; Utsumi, Hiromoto; Ota, Masaji; Nakanishi, Takashi

    1979-01-01

    In the study of possible reduction in irradiation dose to patients during medical treatments, the following two methods can be considered: (1) To obtain absorbed doses for each part of a body in diagnostic X-ray examinations. (2) To obtain data on factors such as the tube voltage which may affect patient dose. There are a number of reports both at home and abroad concerning the above (1), but very few reports are available concerning the above (2). Moreover, most of them are on fragmentary aspects of each factor and no systematic reports have been made. For this reason, we have taken up, as factors affecting the patient dose, the field size, the tube voltage, and by checking them again, we wanted to obtain some systematic data. Our aim has been fully attained by conducting an experiment. In the ICRP's Publ. 26 issued last year, the idea of the critical organ which had not been fully elucidated in the Publ. 9 was abandoned. As a result, assessment of the irradiation doses has become more rational and the total risk for an individual was obtained. In Japan, the idea proposed in the Publ. 9 is adopted. Therefore, in this paper, we will raise some questions regarding the assessment of the irradiation doses, pointing out at the same time the rationality of the idea put forward in Publ. 26. (author)

  6. Evaluation of homogeneity and dose conformity in IMRT planning in prostate radiotherapy; Avaliacao da homogeneidade e conformidade de dose em planejamentos de IMRT de prostata em radioterapia

    Energy Technology Data Exchange (ETDEWEB)

    Lopes, Juliane S.; Leidens, Matheus; Estacio, Daniela R., E-mail: juliane.lopes@pucrs.br [Hospital Sao Lucas (PUC-RS), Porto Alegre, RS (Brazil). Servico de Radioterapia; Razera, Ricardo A.Z.; Streck, Elaine E.; Silva, Ana M.M. da [Pontificia Universidade Catolica do Rio Grande do Sul (PUC-RS), Porto Alegre, RS (Brazil). Faculdade de Fisica

    2015-12-15

    The goal of this study was to evaluate the dose distribution homogeneity and conformity of radiation therapy plans of prostate cancer using IMRT. Data from 34 treatment plans of Hospital Sao Lucas of PUCRS, where those plans were executed, were retrospectively analyzed. All of them were done with 6MV X-rays from a linear accelerator CLINAC IX, and the prescription doses varied between 60 and 74 Gy. Analyses showing the homogeneity and conformity indices for the dose distribution of those plans were made. During these analyses, some comparisons with the traditional radiation therapy planning technic, the 3D-CRT, were discussed. The results showed that there is no correlation between the prescribed dose and the homogeneity and conformity indices, indicating that IMRT works very well even for higher doses. Furthermore, a comparison between the results obtained and the recommendations of ICRU 83 was carried out. It has also been observed that the indices were really close to the ideal values. 82.4% of the cases showed a difference below 5% of the ideal value for the index of conformity, and 88.2% showed a difference below 10% for the homogeneity index. Concluding, it is possible to confirm the quality of the analyzed radiation therapy plans of prostate cancer using IMRT. (author)

  7. Evaluation of the appropriateness of imipenem/cilastatin prescription and dosing in a tertiary care hospital

    Directory of Open Access Journals (Sweden)

    Kabbara WK

    2015-03-01

    Full Text Available Wissam K Kabbara, George T Nawas, Wijdan H RamadanDepartment of Pharmacy Practice, School of Pharmacy, Lebanese American University, Byblos, Lebanon Background: Imipenem/cilastatin is an antibacterial agent of the carbapenem class of β-lactams that is known to have an extremely wide spectrum of activity against Gram-positive, Gram-negative, aerobic, anaerobic, and even multidrug-resistant strains. The objective of this study was to evaluate the appropriate use of imipenem/cilastatin in a local tertiary care hospital. The study assessed the indication both empirically and after the culture results were available, the dose and dose adjustment in renal failure, as well as the incidence of seizure in hospitalized patients receiving imipenem/cilastatin. Methods: This observational study was conducted in a tertiary care hospital over a 3-month period. The treatment of 100 patients with imipenem/cilastatin was evaluated both empirically and after culture results were available. Analysis of the appropriateness of imipenem/cilastatin indication, dose, and monitoring of seizure frequency was based on the package insert, updated published guidelines, and clinical judgment. Results: Patients from internal medicine and intensive care units comprised approximately 50% of the population in the study. The patients received imipenem/cilastatin mainly for urinary tract infections (27% or for sepsis of an unknown focus (22%. The use of imipenem/cilastatin empirically was appropriate in 97.2% (n=69/71 of the cases, and its use postculture in 86% of the cases. There were 29% of the patients who were not started on imipenem/cilastatin empirically. Four patients out of the 29 patients (13.8% who were not started on imipenem/cilastatin empirically inappropriately received imipenem/cilastatin post-culture results. Thirty-three patients (33% were not dosed appropriately, 30 of whom had renal impairment and creatinine clearance fluctuations. Only one patient developed a

  8. Scoping calculation for components of the cow-milk dose pathway for evaluating the dose contribution from iodine-131

    International Nuclear Information System (INIS)

    Ikenberry, T.A.; Napier, B.A.

    1992-12-01

    A series of scoping calculations have been undertaken to evaluate The absolute and relative contribution of different exposure pathways to doses that may have been received by individuals living in the vicinity of the Hanford site. This scoping calculation (Calculation 001) examined the contributions of the various exposure pathways associated with environmental transport and accumulation of iodine-131 in the pasture-cow-milk pathway. Addressed in this calculation were the contributions to thyroid dose of infants and adult from (1) the ingestion by dairy cattle of various feedstuffs (pasturage, silage, alfalfa hay, and grass hay) in four different feeding regimes; (2) ingestion of soil by dairy cattle; (3) ingestion of stared feed on which airborne iodine-131 had been deposited; and (4) inhalation of airborne iodine-131 by dairy cows

  9. Studying the potential of point detectors in time-resolved dose verification of dynamic radiotherapy

    International Nuclear Information System (INIS)

    Beierholm, A.R.; Behrens, C.F.; Andersen, C.E.

    2015-01-01

    Modern megavoltage x-ray radiotherapy with high spatial and temporal dose gradients puts high demands on the entire delivery system, including not just the linear accelerator and the multi-leaf collimator, but also algorithms used for optimization and dose calculations, and detectors used for quality assurance and dose verification. In this context, traceable in-phantom dosimetry using a well-characterized point detector is often an important supplement to 2D-based quality assurance methods based on radiochromic film or detector arrays. In this study, an in-house developed dosimetry system based on fiber-coupled plastic scintillator detectors was evaluated and compared with a Farmer-type ionization chamber and a small-volume ionization chamber. An important feature of scintillator detectors is that the sensitive volume of the detector can easily be scaled, and five scintillator detectors of different scintillator length were thus employed to quantify volume averaging effects by direct measurement. The dosimetric evaluation comprised several complex-shape static fields as well as simplified dynamic deliveries using RapidArc, a volumetric-modulated arc therapy modality often used at the participating clinic. The static field experiments showed that the smallest scintillator detectors were in the best agreement with dose calculations, while needing the smallest volume averaging corrections. Concerning total dose measured during RapidArc, all detectors agreed with dose calculations within 1.1 ± 0.7% when positioned in regions of high homogenous dose. Larger differences were observed for high dose gradient and organ at risk locations, were differences between measured and calculated dose were as large as 8.0 ± 5.5%. The smallest differences were generally seen for the small-volume ionization chamber and the smallest scintillators. The time-resolved RapidArc dose profiles revealed volume-dependent discrepancies between scintillator and ionization chamber response

  10. Dose area product evaluations with Gafchromic[reg] XR-R films and a flat-bed scanner

    International Nuclear Information System (INIS)

    Rampado, O; Garelli, E; Deagostini, S; Ropolo, R

    2006-01-01

    Gafchromic[reg] XR-R films are a useful tool to evaluate entrance skin dose in interventional radiology. Another dosimetric quantity of interest in diagnostic and interventional radiology is the dose area product (DAP). In this study, a method to evaluate DAP using Gafchromic[reg] XR-R films and a flat-bed scanner was developed and tested. Film samples were exposed to an x-ray beam of 80 kVp over a dose range of 0-10 Gy. DAP measurements with films were obtained from the digitalization of a film sample positioned over the x-ray beam window during the exposure. DAP values obtained with this method were compared for 23 cardiological interventional procedures with DAP values displayed by the equipment. The overall one-sigma dose measurement uncertainty depended on the absorbed dose, with values below 6% for doses above 1 Gy. A maximum discrepancy of 16% was found, which is of the order of the differences in the DAP measurements that may occur with different calibration procedures. Based on the results presented, after an accurate calibration procedure and a thorough inspection of the relationship between the actual dose and the direct measured quantity (net optical density or net pixel value variation), Gafchromic[reg] XR-R films can be used to assess the DAP. (note)

  11. Dose area product evaluations