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Satish C Uniyal, Vineet Chaturvedi, Sunil D Sharma, Anurag Rawat
Cardiac interventions often result in high radiation dose to patient's skin, so a reliable indicator in terms of a commonly used dose descriptor is required to monitor skin exposures. In the present study, Gafchromic XR-RV3 film was used to measure the peak skin dose (PSD) during 40 coronary angiography (CA) and 50 percutaneous transluminal coronary angioplasty (PTCA) procedures. Corresponding values of kerma-area product (PKA), fluoroscopy time (FT) and reference air-kerma (Ka,r) were recorded and correlated with PSD...
October 15, 2016: Radiation Protection Dosimetry
Yuta Matsunaga, Ai Kawaguchi, Masanao Kobayashi, Shigetaka Suzuki, Shoichi Suzuki, Koichi Chida
The purposes of this study were (1) to compare the radiation doses for 320- and 80-row fetal-computed tomography (CT), estimated using thermoluminescent dosimeters (TLDs) and the ImPACT Calculator (hereinafter referred to as the "CT dosimetry software"), for a woman in her late pregnancy and her fetus and (2) to estimate the overlapped fetal radiation dose from a 320-row CT examination using two different estimation methods of the CT dosimetry software. The direct TLD data in the present study were obtained from a previous study...
September 19, 2016: Radiological Physics and Technology
William T Wilson, Tristan McMillan, Adam M H Young, Mark A J White
INTRODUCTION: Treatment-limiting decisions (TLDs) are employed to actively withhold treatment from patients whom clinicians feel would derive no benefit or suffer detrimental effects from further intervention. The use of such decisions has been heavily discussed in the media and clinicians in the past have been reluctant to institute them, even though it is in the best interests of the patients. Their use is influenced by several ethical, religious and social factors all of which have changed significantly over time...
September 1, 2016: British Journal of Neurosurgery
Moritz Wildgruber, René Müller-Wille, Holger Goessmann, Wibke Uller, Walter A Wohlgemuth
OBJECTIVE: The aim of the study was to calculate the effective dose during fluoroscopy-guided pediatric interventional procedures of the liver in a phantom model before and after adjustment of preset parameters. METHODS: Organ doses were measured in three anthropomorphic Rando-Alderson phantoms representing children at various age and body weight (newborn 3.5kg, toddler 10kg, child 19kg). Collimation was performed focusing on the upper abdomen representing mock interventional radiology procedures such as percutaneous transhepatic cholangiography and drainage placement (PTCD)...
2016: PloS One
M Zehtabian, N Dehghan, M Danaei Ghazanfarkhani, M Haghighatafshar, S Sina
The family members or friends of the patients undergoing treatment using radioiodine in nuclear medicine are inevitably exposed to ionization radiation. The purpose of this study is measurement of the dose received by the people taking care of the thyroid cancer patients treated by (131)I. For this purpose, the dose amounts received by 29 people accompanying patients were measured using thermoluminescence dosimeters. A badge containing three TLD-100 chips was given to each caregiver. The people were asked to wear the badges for 24 days, when they are taking care of the patients...
August 22, 2016: Radiation Protection Dosimetry
J Hudzietzova, M Fulop, J Sabol
BACKGROUND: The current routinely used methods of estimating the skin equivalent dose relies on the finger dosimetry which usually largely underestimates the real maximum exposure and thus appropriate correction factors have to be used. METHODS: The group under the investigation consisted of 10 workers preparing and 5 workers administering radiopharmaceuticals labelled with 18F. The monitoring was carried out using 12 pairs of thermoluminiscent dosimeters (TLDs) placed on each hand of the worker...
2016: Bratislavské Lekárske Listy
Hannele Niiniviita, Timo Kiljunen, Jarmo Kulmala
This study compares the image quality and the patient doses on seven different computed tomography (CT) scanners for newborn chest imaging. The dose was measured by using an anthropomorphic newborn phantom and thermoluminescence dosemeters (TLDs). The effective dose was estimated separately based on a dose-length-product display, TLD measurements and the ImPACT CT dose calculation software. The image quality was assessed using a signal-to-noise ratio and a contrast-to-noise ratio (CNR). In order to compare the different scanners, a figure of merit (FOM) based on the rate of CNR(2) and computed tomography dose index (CTDIvol) was calculated...
August 13, 2016: Radiation Protection Dosimetry
M J Fartaria, C Reis, J Pereira, M F Pereira, J V Cardoso, L M Santos, C Oliveira, V Holovey, A Pascoal, J G Alves
The aim of this paper is the characterization of four thermoluminescence detectors (TLD), namely, LiF:Mg,Ti, LiF:Mg,Cu,P, Li2B4O7:Mn and Li2B4O7:Cu for the measurement of the entrance surface air kerma (ESAK) and estimation of the mean glandular dose (MGD) in digital mammography examinations at hospitals and clinics. Low-energy x-ray beams in the typical energy ranges of mammography, produced with a tungsten target and additional 60 µm molybdenum filtration were implemented and characterized at the Laboratory of Metrology of Ionizing Radiation at Instituto Superior Técnico...
September 7, 2016: Physics in Medicine and Biology
Yannick Poirier, Mauro Tambasco
We present an experimental validation of a kilovoltage (kV) X-ray source characterization model in an anthropomorphic phantom to estimate patient-specific absorbed dose from kV cone-beam computed tomography (CBCT) imaging procedures and compare these doses to nominal weighted CT-dose index (CTDIw) dose estimates. We simulated the default Varian on-board imager 1.4 (OBI) default CBCT imaging protocols (i.e., standard-dose head, low-dose thorax, pelvis, and pelvis spotlight) using our previously developed and easy to implement X-ray point-source model and source characterization approach...
2016: Journal of Applied Clinical Medical Physics
Seung-Jae Hyun, Ki-Jeong Kim, Tae-Ahn Jahng, Hyun-Jib Kim
BACKGROUND: Despite the firmly established occupational risk of exposure to X-rays, they are used extensively in spine surgeries. Shielding by lead aprons is the most common protective practice. We quantified the level of their radiation blocking ability in a real-life setting. METHODS: Single-center, prospective, randomized study of adult patients with degenerative lumbar disorders, scheduled to undergo posterior lumbar interbody fusion. Instrumentation was performed in either a robot-assisted, minimally invasive approach (RO) or a conventional, fluoroscopically-assisted, open approach (FA)...
May 2016: Heliyon
Nika Guberina, Saravanabavaan Suntharalingam, Kai Naßenstein, Michael Forsting, Jens Theysohn, Axel Wetter, Adrian Ringelstein
INTRODUCTION: The aim of this study was to verify the results of a dose monitoring software tool based on Monte Carlo Simulation (MCS) in assessment of eye lens doses for cranial CT scans. METHODS: In cooperation with the Federal Office for Radiation Protection (Neuherberg, Germany), phantom measurements were performed with thermoluminescence dosimeters (TLD LiF:Mg,Ti) using cranial CT protocols: (I) CT angiography; (II) unenhanced, cranial CT scans with gantry angulation at a single and (III) without gantry angulation at a dual source CT scanner...
July 20, 2016: Neuroradiology
YoungJu Lee, Yuho Won, Kidoo Kang
In Korea, radiation workers must wear personal dosemeters when they enter radiation-controlled areas. For the purpose of daily or job-related exposure control, a supplemental dosemeter, such as an active personal dosemeter (APD), is used in addition to the thermo-luminescence dosemeter (TLD) checked once a month for official records. However, with the development of improved multi-detector, APDs, it has become possible to consider using these devices in the manner in which passive dosemeters are used. Thus, a comparison was done by means of a performance test according to the legal dosimetric performance criteria for official dosemeters to confirm the possibility of using an APD as an official dosemeter...
July 18, 2016: Radiation Protection Dosimetry
T Haninger, P Kleinau, S Haninger
The new albedo dosemeter-type AWST-TL-GD 04 has been calibrated in the CERF neutron field (Cern-EU high-energy Reference Field). This type of albedo dosemeter is based on thermoluminescent detectors (TLDs) and used by the individual monitoring service of the Helmholtz Zentrum München (AWST) since 2015 for monitoring persons, who are exposed occupationally against photon and neutron radiation. The motivation for this experiment was to gain a field specific neutron correction factor Nn for workplaces at high-energy particle accelerators...
July 15, 2016: Radiation Protection Dosimetry
Yan-Jun Huang, Gui-Yin Guo, Yi He, Li-Tao Yang, Zhen Shan, Chao-Feng Chen, Zhi-Hong Shang-Guan
In this paper, three different widely-used measurement techniques for environmental gamma dose rate were studied and compared, i.e., the thermoluminescent dosimeter, the portable survey meter and the spectrometric analysis. Thirteen investigation sites were selected, and the TLDs were arranged to accumulate the radiation signals during an interval of about one quarter, the instant dose rates by using a portable survey meter were collected around the site, and top surface soils were sampled in the surroundings for radionuclides analyzing in laboratory...
June 30, 2016: Journal of Environmental Radioactivity
Hualiang Zhong, Jeffrey Adams, Carri Glide-Hurst, Hualin Zhang, Haisen Li, Indrin J Chetty
Adaptive radiotherapy may improve treatment outcomes for lung cancer patients. Because of the lack of an effective tool for quality assurance, this therapeutic modality is not yet accepted in clinic. The purpose of this study is to develop a deformable physical phantom for validation of dose accumulation algorithms in regions with heterogeneous mass. A three-dimensional (3D) deformable phantom was developed containing a tissue-equivalent tumor and heterogeneous sponge inserts. Thermoluminescent dosimeters (TLDs) were placed at multiple locations in the phantom each time before dose measurement...
April 2016: Journal of Medical Physics
J Benjamin Jackson, Anthony Crimaldi, Richard Peindl, H James Norton, William E Anderson, Joshua C Patt
STUDY DESIGN: Cadaveric Model OBJECTIVES.: To compare effect of PEEK vs conventional implants on scatter radiation to a simulated tumor bed in the spine SUMMARY OF BACKGROUND DATA.: Given the highly vasculature nature of the spine it is the most common place for bony metastases. After surgical treatment of a spinal metastasis, adjuvant radiation therapy is typically administered. Radiation dosing is primarily limited by toxicity to the spinal cord. The scatter effect caused by metallic implants decreases the accuracy of dosing and can unintentionally increase the effective dose seen by the spinal cord...
May 18, 2016: Spine
Andrea Steuwe, Philipp Geisbüsch, Christof J Schulz, Dittmar Böckler, Hans-Ulrich Kauczor, Wolfram Stiller
PURPOSE: To compare the radiation exposure associated with intraoperative contrast-enhanced cone-beam computed tomography (ceCBCT) acquisitions to standard 3-phase multidetector computed tomography (MDCT) angiography used for assessing technical success after endovascular aortic repair (EVAR). METHODS: Effective doses (EDs) were calculated for 66 EVAR patients (mean age 71 years; 61 men) with a mean 27.7-kg/m(2) body mass index (range 17-49) who had both intraoperative ceCBCT and postoperative 3-phase MDCT angiography between November 2012 and April 2015...
August 2016: Journal of Endovascular Therapy
Osvaldo Rampado, Francesca Romana Giglioli, Veronica Rossetti, Christian Fiandra, Riccardo Ragona, Roberto Ropolo
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...
May 2016: Medical Physics
Ilias V Karagounis, Ioannis M Abatzoglou, Michael I Koukourakis
PURPOSE: In vivo radiobiology experiments involving partial body irradiation (PBI) of mice are of major importance because they allow for the evaluation of individual organ tolerance; overcoming current limitations of experiments using lower dose, whole body irradiation. In the current study, the authors characterize and validate an effective and efficient apparatus for multiple animal PBI, directed to the head, thorax, or abdomen of mice. METHODS: The apparatus is made of polymethylmethacrylate and consists of a rectangular parallelepiped prism (40 cm × 16 cm × 8 cm), in which five holes were drilled to accomodate standard 60 ml syringes, each housing an unanesthetized, fully immobilized mouse...
May 2016: Medical Physics
Alberto Ciarmatori, L Nocetti, G Mistretta, G Zambelli, T Costi
The eye lens is considered to be among the most radiosensitive human tissues. Brain CT scans may unnecessarily expose it to radiation even if the area of clinical interest is far from the eyes. The aim of this study is to implement a bismuth eye lens shielding system for Head-CT acquisitions in these cases. The study is focused on the assessment of the dosimetric characteristics of the shielding system as well as on its effect on image quality. The shielding system was tested in two set-ups which differ for distance ("contact" and "4 cm" Set up respectively)...
June 2016: Australasian Physical & Engineering Sciences in Medicine
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