Download or read book Spectral Measurements and Carcinogenic Effects Modeling of Secondary Neutrons in Radiation Therapy written by Logan Montgomery and published by . This book was released on 2022 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: "During high-energy radiation therapy, patients are exposed to a spectrum of secondary neutrons that pose an iatrogenic cancer risk. This risk is qualitatively encapsulated by quantities such as the International Commission on Radiological Protection's neutron weighting factors. These factors convey neutron relative biological effectiveness (RBE) for inducing stochastic radiobiological effects and are characterized by a marked energy dependence. However, there is lack of direct evidence as to the biophysical mechanisms underlying this energy dependence. The overall goal of this thesis was to advance our understanding of the carcinogenic risk posed by secondary neutrons to radiation therapy patients. This goal required knowledge of both the neutron spectra encountered in radiation therapy and how those spectra cause radiobiological effects. Therefore, two objectives were set:1) Demonstrate our ability to accurately measure neutron spectra produced in clinically-relevant scenarios.2) Develop a Monte Carlo model to investigate the biophysical mechanisms underlying the energy dependence of neutron RBE for stochastic effects. Two studies were conducted pertaining to objective #1. In the first study, a Nested Neutron Spectrometer (NNS) was used to measure and compare the neutron spectra produced by a 10 MV flattening-filter-free (FFF) beam and a conventional, flattened 10 MV beam. It was found that the FFF beam reduced the neutron fluence by 30-40% per monitor unit (MU) without appreciable change to the spectral shape. The primary cause of this reduction was found to be a decrease in the number of electrons striking the linac bremsstrahlung target per MU, rather than the removal of a source of neutrons in the flattening filter itself. The second study was designed to address a lack of objectivity in the process of unfolding raw NNS measurements into neutron spectra. The maximum-likelihood expectation-maximization (MLEM) algorithm that is used to unfold NNS measurements is an iterative process that requires a stopping criterion. Previously, the MLEM algorithm was terminated after a fixed number of iterations based on subjective user input, resulting in both intra-user and inter-user variations. In this study, an objective stopping criterion was developed that terminates unfolding at an optimal number of iterations without user input. Finally, a third study was conducted with regards to objective #2. The propensity of radiation to induce clusters of DNA damage is widely believed to be the primary initiating event for radiation-induced mutagenesis and subsequent carcinogenesis because clustered lesions are difficult to repair and rarely occur endogenously. Thus, a Monte Carlo application was developed to simulate the irradiation of nuclear DNA and score the resulting yields of clustered DNA damage. Simulations were performed for neutron energies between 1 and 10 MeV and a reference 250 keV x-ray radiation. The resulting neutron RBE for inducing clustered DNA damage exhibited qualitatively similar energy dependence to the published neutron weighting factors. This result was robust to a variety of simulation parameters, including low dose irradiation, and thus provides fundamental biophysical evidence towards explaining the energy dependence of neutron RBE for inducing stochastic radiobiological effects. The spectral measurements and Monte Carlo modeling described in this body of work represent marked advancements towards understanding and characterizing the relative carcinogenic risk posed by secondary neutrons to radiation therapy patients. This research was conducted in the spirit of open science and, as such, the unfolding algorithm and Monte Carlo application developed in this work were released under open-source licenses"--
Download or read book Proton Therapy Physics written by Harald Paganetti and published by CRC Press. This book was released on 2016-04-19 with total page 691 pages. Available in PDF, EPUB and Kindle. Book excerpt: Proton Therapy Physics goes beyond current books on proton therapy to provide an in-depth overview of the physics aspects of this radiation therapy modality, eliminating the need to dig through information scattered in the medical physics literature. After tracing the history of proton therapy, the book summarizes the atomic and nuclear physics background necessary for understanding proton interactions with tissue. It describes the physics of proton accelerators, the parameters of clinical proton beams, and the mechanisms to generate a conformal dose distribution in a patient. The text then covers detector systems and measuring techniques for reference dosimetry, outlines basic quality assurance and commissioning guidelines, and gives examples of Monte Carlo simulations in proton therapy. The book moves on to discussions of treatment planning for single- and multiple-field uniform doses, dose calculation concepts and algorithms, and precision and uncertainties for nonmoving and moving targets. It also examines computerized treatment plan optimization, methods for in vivo dose or beam range verification, the safety of patients and operating personnel, and the biological implications of using protons from a physics perspective. The final chapter illustrates the use of risk models for common tissue complications in treatment optimization. Along with exploring quality assurance issues and biological considerations, this practical guide collects the latest clinical studies on the use of protons in treatment planning and radiation monitoring. Suitable for both newcomers in medical physics and more seasoned specialists in radiation oncology, the book helps readers understand the uncertainties and limitations of precisely shaped dose distribution.
Download or read book Health Effects of Exposure to Low Levels of Ionizing Radiation written by National Research Council and published by National Academies. This book was released on 1990-02-01 with total page 436 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book reevaluates the health risks of ionizing radiation in light of data that have become available since the 1980 report on this subject was published. The data include new, much more reliable dose estimates for the A-bomb survivors, the results of an additional 14 years of follow-up of the survivors for cancer mortality, recent results of follow-up studies of persons irradiated for medical purposes, and results of relevant experiments with laboratory animals and cultured cells. It analyzes the data in terms of risk estimates for specific organs in relation to dose and time after exposure, and compares radiation effects between Japanese and Western populations.
Download or read book Radiation Oncology Physics written by International Atomic Energy Agency and published by IAEA. This book was released on 2005 with total page 704 pages. Available in PDF, EPUB and Kindle. Book excerpt: This publication is aimed at students and teachers involved in teaching programmes in field of medical radiation physics, and it covers the basic medical physics knowledge required in the form of a syllabus for modern radiation oncology. The information will be useful to those preparing for professional certification exams in radiation oncology, medical physics, dosimetry or radiotherapy technology.
Download or read book Neutron Monitoring for Radiological Protection written by J. A. B. Gibson and published by . This book was released on 1985 with total page 244 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Health Risks from Exposure to Low Levels of Ionizing Radiation written by Committee to Assess Health Risks from Exposure to Low Levels of Ionizing Radiation and published by National Academies Press. This book was released on 2006-03-23 with total page 422 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is the seventh in a series of titles from the National Research Council that addresses the effects of exposure to low dose LET (Linear Energy Transfer) ionizing radiation and human health. Updating information previously presented in the 1990 publication, Health Effects of Exposure to Low Levels of Ionizing Radiation: BEIR V, this book draws upon new data in both epidemiologic and experimental research. Ionizing radiation arises from both natural and man-made sources and at very high doses can produce damaging effects in human tissue that can be evident within days after exposure. However, it is the low-dose exposures that are the focus of this book. So-called “late” effects, such as cancer, are produced many years after the initial exposure. This book is among the first of its kind to include detailed risk estimates for cancer incidence in addition to cancer mortality. BEIR VII offers a full review of the available biological, biophysical, and epidemiological literature since the last BEIR report on the subject and develops the most up-to-date and comprehensive risk estimates for cancer and other health effects from exposure to low-level ionizing radiation.
Download or read book Research Awards Index written by and published by . This book was released on 1989 with total page 742 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Shielding Techniques for Radiation Oncology Facilities written by Patton H. McGinley and published by Medical Physics Publishing Corporation. This book was released on 2002-01-01 with total page 171 pages. Available in PDF, EPUB and Kindle. Book excerpt: A textbook for a senior or graduate course in medical or health physics. Students are assumed to be familiar with the radiation- producing devices used in radiation oncology. The second volume corrects some errors detected in the 1998 first, and adds discussions of intensity modulated radiation therapy, CT room design, the design of direct shielded doors, and other topics. Annotation copyrighted by Book News Inc., Portland, OR.
Download or read book Out of field second primary cancer induction Radiation biology epidemiology dosimetry and modelling written by Beatriz Sanchez-Nieto and published by Frontiers Media SA. This book was released on 2023-01-06 with total page 177 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1981 with total page 1370 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.
Download or read book Nuclear Science Abstracts written by and published by . This book was released on 1976 with total page 612 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Radiation Protection in the Design of Radiotherapy Facilities written by International Atomic Energy Agency and published by IAEA. This book was released on 2006 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt: Provides practical guidance regarding the design and shielding of radiotherapy facilities. Methods for determining the necessary structural shielding for external beam units (cobalt-60 units, linear accelerators, superficial and orthovoltage units, and simulators), as well as for brachytherapy units, are described.
Download or read book Targeted Radionuclide Therapy written by Tod W. Speer and published by Lippincott Williams & Wilkins. This book was released on 2012-03-28 with total page 564 pages. Available in PDF, EPUB and Kindle. Book excerpt: Radioimmunotherapy, also known as systemic targeted radiation therapy, uses antibodies, antibody fragments, or compounds as carriers to guide radiation to the targets. It is a topic rapidly increasing in importance and success in treatment of cancer patients. This book represents a comprehensive amalgamation of the radiation physics, chemistry, radiobiology, tumor models, and clinical data for targeted radionuclide therapy. It outlines the current challenges and provides a glimpse at future directions. With significant advances in cell biology and molecular engineering, many targeting constructs are now available that will safely deliver these highly cytotoxic radionuclides in a targeted fashion. A companion website includes the full text and an image bank.
Download or read book Radiobiology for the Radiologist written by Eric J. Hall and published by Lippincott Williams & Wilkins. This book was released on 2012-03-28 with total page 908 pages. Available in PDF, EPUB and Kindle. Book excerpt: In print since 1972, this seventh edition of Radiobiology for the Radiologist is the most extensively revised to date. It consists of two sections, one for those studying or practicing diagnostic radiolo, nuclear medicine and radiation oncology; the other for those engaged in the study or clinical practice of radiation oncology--a new chapter, on radiologic terrorism, is specifically for those in the radiation sciences who would manage exposed individuals in the event of a terrorist event. The 17 chapters in Section I represent a general introduction to radiation biology and a complete, self-contained course especially for residents in diagnostic radiology and nuclear medicine that follows the Syllabus in Radiation Biology of the RSNA. The 11 chapters in Section II address more in-depth topics in radiation oncology, such as cancer biology, retreatment after radiotherapy, chemotherapeutic agents and hyperthermia. Now in full color, this lavishly illustrated new edition is replete with tables and figures that underscore essential concepts. Each chapter concludes with a "summary of pertinent conclusions" to facilitate quick review and help readers retain important information.
Download or read book Johns and Cunningham s the Physics of Radiology written by Eva Bezak and published by Charles C. Thomas Publisher. This book was released on 2020-10 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The fifth edition of this respected book encompasses all the advances and changes that have been made since it was last revised. It not only presents new ideas and information, it shifts its emphases to accurately reflect the inevitably changing perspectives in the field engendered by progress in the understanding of radiological physics. The rapid development of computing technology in the three decades since the publication of the fourth edition has enabled the equally rapid expansion of radiology, radiation oncology, nuclear medicine and radiobiology. This book is written to help the practitioners in these fields understand the physical science, as well as to serve as a basic tool for physics students who intend working as medical radiation physicists in these clinical fields.
Download or read book Encyclopedia of Nuclear Energy written by and published by Elsevier. This book was released on 2021-07-15 with total page 3656 pages. Available in PDF, EPUB and Kindle. Book excerpt: Encyclopedia of Nuclear Energy provides a comprehensive and reliable overview of the many ways nuclear energy contributes to society. Comprised of four volumes, it includes topics such as generating clean electricity, improving medical diagnostics and cancer treatment, improving crop yields, improving food shelf-lives, and crucially, the deployment of nuclear energy as an alternative energy source, one that is proving to be essential in the management of global warming. Carefully structured into thematic sections, this encyclopedia brings together the vast and highly diversified literature related to nuclear energy into a single resource, with convenient to read, cross-referenced chapters. This book will serve as an invaluable resource for researchers in the fields of energy, engineering, material science, chemistry, and physics, from both industry and academia. Offers a contemporary review of current nuclear energy research and insights into the future direction of the field, hence negating the need for individual searches across various databases Written by academics and practitioners from different fields to ensure that the knowledge within is easily understood by, and applicable to, a large audience Meticulously organized, with articles split into sections on key topics and clearly cross-referenced to allow students, researchers and professionals to quickly and easily find relevant information
Download or read book Reducing Environmental Cancer Risk written by Suzanne H. Reuben and published by DIANE Publishing. This book was released on 2010-10 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt: Though overall cancer incidence and mortality have continued to decline in recent years, cancer continues to devastate the lives of far too many Americans. In 2009 alone, 1.5 million American men, women, and children were diagnosed with cancer, and 562,000 died from the disease. There is a growing body of evidence linking environmental exposures to cancer. The Pres. Cancer Panel dedicated its 2008¿2009 activities to examining the impact of environmental factors on cancer risk. The Panel considered industrial, occupational, and agricultural exposures as well as exposures related to medical practice, military activities, modern lifestyles, and natural sources. This report presents the Panel¿s recommend. to mitigate or eliminate these barriers. Illus.
