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Ryan Manger, Douglas Rahn, Jeremy Hoisak, Irena Dragojević
PURPOSE: To develop an improved Xoft electronic skin brachytherapy process and identify areas of further improvement. METHODS AND MATERIALS: A multidisciplinary team conducted a failure modes and effects analysis (FMEA) by developing a process map and a corresponding list of failure modes. The failure modes were scored for their occurrence, severity, and detectability, and a risk priority number (RPN) was calculated for each failure mode as the product of occurrence, severity, and detectability...
May 14, 2018: Brachytherapy
Oded Hod, Michael Urbakh, Doron Naveh, Maya Bar-Sadan, Ariel Ismach
The experimental identification of fullerenes in 1985, carbon nanotubes in 1991, inorganic nanotubes in 1992, and graphene in 2004 are cornerstone events that have marked the beginning of the layered nanostructures era of materials science. Nowadays, the synthesis of such low-dimensional systems is a routine practice allowing the controlled fabrication of 0-, 1-, and 2D layered structures of diverse chemical compositions. These systems possess unique physical properties that stem from their structural anisotropy characterized by strong intralayer covalent bonding and weaker interlayer dispersive interactions...
May 16, 2018: Advanced Materials
Daniel Sanchez-Parcerisa, Jose Udías
Open-source, MATLAB-based treatment planning systems FoCa and matRAD were used in a pilot project for training prospective medical physicists and postgraduate physics students in treatment planning and beam modeling techniques for proton therapy. In the four exercises designed, students learnt how proton pencil beams are modeled and how dose is calculated in three-dimensional voxelized geometries, how pencil beam scanning plans (PBS) are constructed, the rationale behind the choice of spot spacing in patient plans, and the dosimetric differences between photon IMRT and proton PBS plans...
May 12, 2018: Journal of Applied Clinical Medical Physics
John S Torday
Biology has remained descriptive since its formalization by Linnaeus in the 18th Century. Dobzhansky has challenged us to think mechanistically by stating that 'Nothing in Biology makes sense except in the light of evolution', but NeoDarwinian evolution remains untestable or refutable. The physicist Bohm has encouraged us to recognize that our perception of 'reality' is mediated by our evolved, subjective senses, though there is a coherent Implicate Order just out of reach. Only recently has a novel understanding of physiologic evolution based on cell-cell communication for embryonic development and phylogeny offered the opportunity to mechanistically merge Quantum Mechanics with Evolutionary Biology...
May 2, 2018: Progress in Biophysics and Molecular Biology
Sarah E McKenney, Cristina T Dodge
No abstract text is available yet for this article.
May 7, 2018: Journal of the American College of Radiology: JACR
Sotiria Triantopoulou, Kalliopi Platoni, Christos Antypas, Pantelis Karaiskos, Christina Armpilia, Nikolaos Uzunoglou, Vassilis Kouloulias
PURPOSE: During the last years hyperthermia is a developing therapeutic modality in Greece. Quality assurance (QA) procedures are essential for ensuring the correct operation of the hyperthermia system and therefore the selective heating of the tumor with minimum toxicity to the surrounding healthy tissues. The European Society for Hyperthermic Oncology (ESHO) has proposed QA guidelines for superficial as well as deep hyperthermia systems. The purpose of this study was to describe the adapted QA protocol for superficial and deep hyperthermia systems established in Greece...
March 2018: Journal of B.U.ON.: Official Journal of the Balkan Union of Oncology
Gérard Lagmago Kamta
The Canadian Organization of Medical Physicists (COMP), in close partnership with the Canadian Partnership for Quality Radiotherapy (CPQR) has developed a series of Technical Quality Control (TQC) guidelines for radiation treatment equipment. These guidelines outline the performance objectives that equipment should meet to ensure an acceptable level of radiation treatment quality. The TQC guidelines have been rigorously reviewed and field tested in a variety of Canadian radiation treatment facilities. The development process enables rapid review and update to keep the guidelines current with changes in technology (the most update version of this guideline can be found on the CPQR website)...
May 9, 2018: Journal of Applied Clinical Medical Physics
Chris Daniel Johnstone, Magdalena Bazalova-Carter
The goal of this work was to establish imaging dose to mouse organs with a validated Monte Carlo (MC) model of the image-guided Small Animal Radiation Research Platform (SARRP) and to investigate the effect of scatter from the internal walls on animal therapy dose determination. A MC model of the SARRP was built in the BEAMnrc code and validated with a series of homogeneous and heterogeneous phantom measurements. A segmented microCT scan of a mouse was used in DOSXYZnrc to determine mouse organ microCT imaging doses to 15-35 g mice for the SARRP pancake (mouse lying on couch) and standard (mouse standing on couch) imaging geometries for 40-80 kVp tube voltages...
May 9, 2018: Physics in Medicine and Biology
Karl Friston
Is self-consciousness necessary for consciousness? The answer is yes. So there you have it-the answer is yes. This was my response to a question I was asked to address in a recent AEON piece ( What follows is based upon the notes for that essay, with a special focus on self-organization, self-evidencing and self-modeling. I will try to substantiate my (polemic) answer from the perspective of a physicist. In brief, the argument goes as follows: if we want to talk about creatures, like ourselves, then we have to identify the characteristic behaviors they must exhibit...
2018: Frontiers in Psychology
Davide Castelvecchi
No abstract text is available yet for this article.
May 2018: Nature
Faiçal A A Slimani, Mahdjoub Hamdi, M'hamed Bentourkia
Monte Carlo (MC) simulation is widely recognized as an important technique to study the physics of particle interactions in nuclear medicine and radiation therapy. There are different codes dedicated to dosimetry applications and widely used today in research or in clinical application, such as MCNP, EGSnrc and Geant4. However, such codes made the physics easier but the programming remains a tedious task even for physicists familiar with computer programming. In this paper we report the development of a new interface GEANT4 Dose And Radiation Interactions (G4DARI) based on GEANT4 for absorbed dose calculation and for particle tracking in humans, small animals and complex phantoms...
May 1, 2018: Computerized Medical Imaging and Graphics: the Official Journal of the Computerized Medical Imaging Society
Gisella Gennaro, Simona Avramova-Cholakova, Andrea Azzalini, Maria Luisa Chapel, Margarita Chevalier, Olivera Ciraj, Hugo de Las Heras, Vesna Gershan, Bengt Hemdal, Elizabeth Keavey, Nico Lanconelli, Susanne Menhart, Màrio João Fartaria, Ana Pascoal, Kristin Pedersen, Stefano Rivetti, Veronica Rossetti, Friedrich Semturs, Peter Sharp, Alberto Torresin
This article aims to present the protocol on Quality Controls in Digital Mammography published online in 2015 by the European Federation of Organisations for Medical Physics (EFOMP) which was developed by a Task Force under the Mammo Working Group. The main objective of this protocol was to define a minimum set of easily implemented quality control tests on digital mammography systems that can be used to assure the performance of a system within a set and acceptable range. Detailed step-by-step instructions have been provided, limiting as much as possible any misinterpretations or variations by the person performing...
April 2018: Physica Medica: PM
Jan C Peeken, Michael Bernhofer, Benedikt Wiestler, Tatyana Goldberg, Daniel Cremers, Burkhard Rost, Jan J Wilkens, Stephanie E Combs, Fridtjof Nüsslin
PURPOSE: Noticing the fast growing translation of artificial intelligence (AI) technologies to medical image analysis this paper emphasizes the future role of the medical physicist in this evolving field. Specific challenges are addressed when implementing big data concepts with high-throughput image data processing like radiomics and machine learning in a radiooncology environment to support clinical decisions. METHODS: Based on the experience of our interdisciplinary radiomics working group, techniques for processing minable data, extracting radiomics features and associating this information with clinical, physical and biological data for the development of prediction models are described...
April 2018: Physica Medica: PM
Davide Castelvecchi
No abstract text is available yet for this article.
May 2018: Nature
Jason C Woods, Mark S Conradi
Hyperpolarized 3 He gas allows the air spaces of the lungs to be imaged via MRI. Imaging of restricted diffusion is addressed here, which allows the microstructure of the lung to be characterized through the physical restrictions to gas diffusion presented by airway and alveolar walls in the lung. Measurements of the apparent diffusion coefficient (ADC) of 3 He at time scales of milliseconds and seconds are compared; measurement of acinar airway sizes by determination of the microscopic anisotropy of diffusion is discussed...
April 25, 2018: Journal of Magnetic Resonance
Jian Zhu, Tong Bai, Jiabing Gu, Ziwen Sun, Yumei Wei, Baosheng Li, Yong Yin
BACKGROUND: To evaluate the effect of pretreatment megavoltage computed tomographic (MVCT) scan methodology on setup verification and adaptive dose calculation in helical TomoTherapy. METHODS: Both anthropomorphic heterogeneous chest and pelvic phantoms were planned with virtual targets by TomoTherapy Physicist Station and were scanned with TomoTherapy megavoltage image-guided radiotherapy (IGRT) system consisted of six groups of options: three different acquisition pitches (APs) of 'fine', 'normal' and 'coarse' were implemented by multiplying 2 different corresponding reconstruction intervals (RIs)...
April 27, 2018: Radiation Oncology
Kendall Elizabeth Berry
Not all healthcare providers can afford to purchase commercially available programs that can quickly and easily provide peak skin dose estimations for patients undergoing diagnostic and international fluoroscopic procedures. The air kerma reference point exposure, Ka,r, available on all equipment manufactured after 2006, may over or under estimate the patient's peak skin dose. The total air kerma reference point exposure provided at the end of a case might be on the order of 20 Gy for a patient, indicating that a Joint Commission 'sentinel event' may have occurred...
June 2018: Health Physics
Jay W Burmeister, Monica W Tracey, Sara E Kacin, Michael M Dominello, Michael C Joiner
The contribution of radiation oncology to the future of cancer treatment depends significantly on our continued clinical progress and future research advancements. Such progress relies on multidisciplinary collaboration among radiation oncologists, medical physicists and radiobiologists. Cultivating collaborative educational and research opportunities among these three disciplines and further investing in the infrastructure used to train both clinicians and researchers will therefore help us improve the future of cancer care...
April 25, 2018: Radiation Research
Charles A Kunos, Holly A Massett, Annette Galassi, Joan L Walker, Marge J Good, Luis Báez Díaz, Worta McCaskill-Stevens
Women in the U.S. Commonwealth of Puerto Rico (PR) have a higher age-adjusted incidence rate for uterine cervix cancer than the U.S. mainland as well as substantial access and economic barriers to cancer care. The National Cancer Institute (NCI) funds a Minority/Underserved NCI Community Oncology Research Program in PR (PRNCORP) as part of a national network of community-based health-care systems to conduct multisite cancer clinical trials in diverse populations. Participation by the PRNCORP in NCI's uterine cervix cancer clinical trials, however, has remained limited...
2018: Frontiers in Oncology
Xuetao Wang, Guangjun Li, Jianling Zhao, Ying Song, Jianghong Xiao, Sen Bai
The eye lens is recognized as one of the most radiosensitive structures in the human body. The widespread use of intensity-modulated radiotherapy (IMRT) complicates dose verification and necessitates high standards of dose computation. The purpose of this work was to assess the computed dose accuracy of eye lens through measurements using a metal-oxide-semiconductor field-effect transistor (MOSFET) dosimetry system. Sixteen clinical IMRT plans of head and neck patients were copied to an anthropomorphic head phantom...
April 17, 2018: Medical Dosimetry: Official Journal of the American Association of Medical Dosimetrists
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