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Sample records for amchitka radiobiological program

  1. Amchitka radiobiological program progress report, January 1976--December 1976

    International Nuclear Information System (INIS)

    The Amchitka Radiobiological Program is a continuing program to collect biological and environmental samples for radiometric analyses. Results of analyses for samples collected during 1976 include gamma-emitting radionuclides in air filters, freshwater, birds, lichens, marine algae, marine invertebrates, fish, aufwuchs, and freshwater moss and plants; 90Sr in rats, birds, and soil; 239240Pu in sand, soil, marine algae and fish; and tritium (3H) in seawater, freshwater, and biological organisms

  2. Amchitka Radiobiological Program progress report, January 1979-December 1979

    International Nuclear Information System (INIS)

    The objective of the Amchitka Radiobiological Program for the period 1970-1979 was to determine the extent of radionuclide contamination from world-wide atmospheric fallout and from the detonation of three underground nuclear blasts on Amchitka Island. The objective is achieved, by the collection and radiological analyses of biological and environmental samples and by background radiation measurements. Leakage of radionuclides from the underground sites of the Amchitka nuclear detonations would be suspected if the contamination was significntly greater than would be expected from world fallout. An account of the program from July 1970 to December 1978 has been given in nine previous reports from the Laboratory of Radiation Ecology to the Nevada Operations Office of the US Department of Energy. This report is an account of the program for calendar year 1979. The results of analyses of the samples collected in 1979 lead to the same conclusions as in previous years; i.e., there is no evidence that the radionuclide contamination at Amchitka Island is greater than would be expected from world fallout except for a slight contamination of the Long Shot Mud Pits with tritium

  3. Amchitka Radiobiological Program. Progress report, January-December 1978

    International Nuclear Information System (INIS)

    The Amchitka Radiobiological Program began in 1970 and is a continuing program to collect biological and environmental samples for radiometric analyses. This report is an account of the program for calendar year 1978. Results of analyses for samples collected in August 1978 have been added to the tables of Seymour and Johnson (1978) which summarize the Amchitka program from 1970 to 1977 and include analyses for: (1) gamma-emitting radionuclides in freshwater, birds, lichens, marine algae, marine invertebrates, fish, aufwuchs, and freshwater moss and plants; (2) strontium-90 (90Sr) in rats, birds, and soil; (3) 239, 240Pu in sand, soil, marine algae, and fish; and (4) tritium (3H) in seawater, freshwater, and biological organisms. Monitoring of background radiation with survey instruments was added to the Laboratory's program in 1974, and the results of the five annual surveys since that date are included in this report. Conclusions from the results of the recent analyses are a reiteration of the results stated in Nelson and Seymour (1975a); namely, (1) no new radionuclides are present; (2) the most abundant radionuclides are naturally occurring beryllium-7 (7Be) and potassium-40 (40K); (3) the trace quantities of fission products and induced radionuclides are from world fallout; and (4) a trace of 3H contamination remains in some Long Shot ponds, as previously reported. It is concluded that there were no radionuclides of Milrow or Cannikin origin in the water, plants, or animals of Amchitka Island

  4. Amchitka Radiobiological Program. Final report, July 1970-December 1979

    International Nuclear Information System (INIS)

    The Amchitka Radiobiological Program, to collect biological and environmental samples for radiological analyses, began in 1970 and continued through 1979. The principal objective was to determine the extent of radionuclide contamination from worldwide atmospheric fallout and from the detonation of three underground nuclear tests on Amchitka. Leakage of radionuclides from the underground test sites would be suspected if the amount of contamination was significantly greater than could be attributed to worldwide fallout or if an unexpected assemblage of radionuclides was detected. No radionuclides from the underground sites were detected, except for tritium from the Long Shot test (1965) which produced increased tritium concentrations in surface water and freshwater plants near the test site. This final report compiles all previous data into one report and considers the temporal trends in these data. Two naturally occurring radionuclides, 40K and 7Be, were the most abundantly occurring radionuclides in most samples; in lichen samples either 137Cs or 144Ce had the highest activity. All samples were below applicable Radiation Protection Guides and by 1979 most samples were near or below the statistical detection limits. Increased concentrations of short-lived fallout radionuclides following the Chinese atmospheric tests were found in freshwater and seawater samples and in most indicator organisms

  5. Amchitka Radiobiological Program. Final report, July 1970-December 1979

    Energy Technology Data Exchange (ETDEWEB)

    Sibley, T.H.; Tornberg, L.D.

    1982-11-01

    The Amchitka Radiobiological Program, to collect biological and environmental samples for radiological analyses, began in 1970 and continued through 1979. The principal objective was to determine the extent of radionuclide contamination from worldwide atmospheric fallout and from the detonation of three underground nuclear tests on Amchitka. Leakage of radionuclides from the underground test sites would be suspected if the amount of contamination was significantly greater than could be attributed to worldwide fallout or if an unexpected assemblage of radionuclides was detected. No radionuclides from the underground sites were detected, except for tritium from the Long Shot test (1965) which produced increased tritium concentrations in surface water and freshwater plants near the test site. This final report compiles all previous data into one report and considers the temporal trends in these data. Two naturally occurring radionuclides, /sup 40/K and /sup 7/Be, were the most abundantly occurring radionuclides in most samples; in lichen samples either /sup 137/Cs or /sup 144/Ce had the highest activity. All samples were below applicable Radiation Protection Guides and by 1979 most samples were near or below the statistical detection limits. Increased concentrations of short-lived fallout radionuclides following the Chinese atmospheric tests were found in freshwater and seawater samples and in most indicator organisms.

  6. Long-Term Hydrologic Monitoring Program, Amchitka Island, Alaska

    International Nuclear Information System (INIS)

    The purpose of the Long-Term Hydrologic Monitoring Program for Amchitka Island, Alaska, is to obtain data that will assure the public safety, inform the public, the news media, and the scientific community relative to radiological contamination, and to document compliance with federal, state, and local antipollution requirements. Amchitka's geographical setting, climate, geology, hydrology, and ecology are described. Site history including event information for LONG SHOT in 1965, MILROW in 1969, and CANNIKIN in 1971 is described. Event related contamination has been observed only at the LONG SHOT site. At this site, tritium in concentrations below the drinking water standards has been observed in mud pits and wells in the area adjacent to surface ground zero. The Long-Term Hydrologic Monitoring Program for Amchitka is described. No radioactive venting, significant radioactive leakage, or bioenvironmental damage resulted from any of the nuclear tests on Amchitka

  7. Amchitka Island, Alaska, special sampling project 1997

    Energy Technology Data Exchange (ETDEWEB)

    U.S. Department of Energy, Nevada Operations Office

    2000-06-28

    This 1997 special sampling project represents a special radiobiological sampling effort to augment the 1996 Long-Term Hydrological Monitoring Program (LTHMP) for Amchitka Island in Alaska. Lying in the western portion of the Aleutian Islands arc, near the International Date Line, Amchitka Island is one of the southernmost islands of the Rat Island Chain. Between 1965 and 1971, the U.S. Atomic Energy Commission conducted three underground nuclear tests on Amchitka Island. In 1996, Greenpeace collected biota samples and speculated that several long-lived, man-made radionuclides detected (i.e., americium-241, plutonium-239 and -240, beryllium-7, and cesium-137) leaked into the surface environment from underground cavities created during the testing. The nuclides of interest are detected at extremely low concentrations throughout the environment. The objectives of this special sampling project were to scientifically refute the Greenpeace conclusions that the underground cavities were leaking contaminants to the surface. This was achieved by first confirming the presence of these radionuclides in the Amchitka Island surface environment and, second, if the radionuclides were present, determining if the source is the underground cavity or worldwide fallout. This special sampling and analysis determined that the only nonfallout-related radionuclide detected was a low level of tritium from the Long Shot test, which had been previously documented. The tritium contamination is monitored and continues a decreasing trend due to radioactive decay and dilution.

  8. Radiobiology

    International Nuclear Information System (INIS)

    This text-book (electronic book - multi-media CD-ROM) constitutes a course-book - author's collection of lectures. It consists of 13 lectures in which the reader acquaints with the basis of radiobiology: Introduction to radiobiology; Physical fundamentals of radiobiology; Radiation of cells; Modification of radiation damage of cells; Reparation of radiation damage of cells; Radiation syndromes and their modification; Radiation injury; Radiation damage of tissues; Effect of radiation on embryo and fetus; Biological effects of incorporated radionuclides; Therapy of acute irradiation sickness; Delayed consequences of irradiation; Radiation oncology and radiotherapy. This course-book may be interesting for students, post-graduate students of chemistry, biology, physics, medicine as well as for teachers, scientific workers and physicians. (author)

  9. Tritium radiobiology research in the US DOE program

    International Nuclear Information System (INIS)

    The history of the original US Atomic Energy Commission, its replacement, the Energy Research and Development Administration, and the present Department of Energy's interest and sponsorship of tritium radiobiology is reviewed beginning in 1971 and continuing through 1986. In particular, the four remaining US Department of Energy, Division of Health and Environmental Research programs are described in some detail

  10. Research in radiobiology. Annual report, Internal Irradiation Program

    International Nuclear Information System (INIS)

    The annual progress report for the Radiobiology Division of the University of Utah College of Medicine is presented. Summaries of twenty-four projects concerning the metabolism, dosimetry and toxicity of a variety of actinide elements in beagles or rats are given. Individual papers within this report have been separately indexed and abstracted for the data base

  11. Alternatives Analysis Amchitka Island Mud Pit Cap Repair, Amchitka, Alaska January 2016

    Energy Technology Data Exchange (ETDEWEB)

    Darr, Paul S. [US Department of Energy, Washington, DC (United States). Office of Legacy Management

    2016-01-01

    The U.S. Department of Energy (DOE) Office of Legacy Management (LM) manages the Nevada Offsites program, which includes a series of reclaimed drilling mud impoundments on Amchitka Island, Alaska (Figure 1). Navarro Research and Engineering, Inc. is the Legacy Management Support contractor (the Contractor) for LM. The Contractor has procured Tetra Tech, Inc. to provide engineering support to the Amchitka mud pit reclamation project. The mud pit caps were damaged during a 7.9-magnitude earthquake that occurred in 2014. The goals of the current project are to investigate conditions at the mud pit impoundments, identify feasible alternatives for repair of the cover systems and the contents, and estimate relative costs of repair alternatives. This report presents descriptions of the sites and past investigations, existing conditions, summaries of various repair/mitigation alternatives, and direct, unburdened, order-of-magnitude (-15% to +50%) associated costs.

  12. Preparatory study of a ground-based space radiobiology program in Europe

    Science.gov (United States)

    Durante, M.; Kraft, G.; O'Neill, P.; Reitz, G.; Sabatier, L.; Schneider, U.

    Space radiation has long been acknowledged as a potential showstopper for long duration manned interplanetary missions. Our knowledge of biological effects of cosmic radiation in deep space is almost exclusively derived from ground-based accelerator experiments with heavy ions in animal or in vitro models. In an effort to gain more information on space radiation risk and to develop countermeasures, NASA initiated several years ago a Space Radiation Health Program, which is currently supporting biological experiments performed at the Brookhaven National Laboratory. Accelerator-based radiobiology research in the field of space radiation research is also under way in Russia and Japan. The European Space Agency (ESA) has recently established an ambitious exploration program (AURORA), and within this program it has been decided to include a space radiation research program. Europe has a long tradition in radiobiology research at accelerators, generally focussing on charged-particle cancer therapy. This expertise can be adapted to address the issue of space radiation risk. To support research in this field in Europe, ESA issued a call for tender in 2005 for a preliminary study of investigations on biological effects of space radiation (IBER). This study will provide guidance on future ESA-supported activities in space radiation research by identifying the most appropriate European accelerator facilities to be targeted for cooperation, and by drafting a roadmap for future research activities. The roadmap will include a prioritisation of research topics, and a detailed proposal for experimental campaigns for the following 5 10 years.

  13. Amchitka, Alaska Site Fact Sheet

    Energy Technology Data Exchange (ETDEWEB)

    None

    2011-12-15

    Amchitka Island is near the western end of the Aleutian Island chain and is the largest island in the Rat Island Group that is located about 1,340 miles west-southwest of Anchorage, Alaska, and 870 miles east of the Kamchatka Peninsula in eastern Russia. The island is 42 miles long and 1 to 4 miles wide, with an area of approximately 74,240 acres. Elevations range from sea level to more than 1,100 feet above sea level. The coastline is rugged; sea cliffs and grassy slopes surround nearly the entire island. Vegetation on the island is low-growing, meadow-like tundra grasses at lower elevations. No trees grow on Amchitka. The lowest elevations are on the eastern third of the island and are characterized by numerous shallow lakes and heavily vegetated drainages. The central portion of the island has higher elevations and fewer lakes. The westernmost 3 miles of the island contains a windswept rocky plateau with sparse vegetation.

  14. Amchitka, Alaska Site Fact Sheet

    International Nuclear Information System (INIS)

    Amchitka Island is near the western end of the Aleutian Island chain and is the largest island in the Rat Island Group that is located about 1,340 miles west-southwest of Anchorage, Alaska, and 870 miles east of the Kamchatka Peninsula in eastern Russia. The island is 42 miles long and 1 to 4 miles wide, with an area of approximately 74,240 acres. Elevations range from sea level to more than 1,100 feet above sea level. The coastline is rugged; sea cliffs and grassy slopes surround nearly the entire island. Vegetation on the island is low-growing, meadow-like tundra grasses at lower elevations. No trees grow on Amchitka. The lowest elevations are on the eastern third of the island and are characterized by numerous shallow lakes and heavily vegetated drainages. The central portion of the island has higher elevations and fewer lakes. The westernmost 3 miles of the island contains a windswept rocky plateau with sparse vegetation

  15. Marine mammal observations, Amchitka Island, Alaska

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Three marine mammals were regularly observed at Amchitka Island: sea otters (Enhydra lutris), Steller's sea lions (Eumetopias jubata), and harbor seals (Phoca...

  16. Breeding peregrine falcon survey, Amchitka Island, Alaska

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — A breeding peregrine falcon (Falco peregrines) survey was conducted on Amchitka Island, Alaska Maritime National Wildlife Refuge from May 2-9, 1981 in conjunction...

  17. Amchitka beach surveys, 1978-1980

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Surveys of 16 beaches on Amchitka Island began 28 October 1978 as part of Alaska Beached Bird Survey. The purpose of the surveys is to provide baseline data on...

  18. SURFACE REMEDIATION IN THE ALEUTIAN ISLANDS: A CASE STUDY OF AMCHITKA ISLAND, ALASKA

    Energy Technology Data Exchange (ETDEWEB)

    Giblin, M. O.; Stahl, D. C.; Bechtel, J. A.

    2002-02-25

    Amchitka Island, Alaska, was at one time an integral player in the nation's defense program. Located in the North Pacific Ocean in the Aleutian Island archipelago, the island was intermittently inhabited by several key government agencies, including the U.S. Army, the U.S. Atomic Energy Commission (predecessor agency to the U.S. Department of Energy), and the U.S. Navy. Since 1993, the U.S. Department of Energy (DOE) has conducted extensive investigations on Amchitka to determine the nature and extent of contamination resulting from historic nuclear testing. The uninhabited island was the site of three high-yield nuclear tests from 1965 to 1971. These test locations are now part of the DOE's National Nuclear Security Administration Nevada Operations Office's Environmental Management Program. In the summer of 2001, the DOE launched a large-scale remediation effort on Amchitka to perform agreed-upon corrective actions to the surface of the island. Due to the lack of resources available on Amchitka and logistical difficulties with conducting work at such a remote location, the DOE partnered with the Navy and U.S. Army Corps of Engineers (USACE) to share certain specified costs and resources. Attempting to negotiate the partnerships while organizing and implementing the surface remediation on Amchitka proved to be a challenging endeavor. The DOE was faced with unexpected changes in Navy and USACE scope of work, accelerations in schedules, and risks associated with construction costs at such a remote location. Unfavorable weather conditions also proved to be a constant factor, often slowing the progress of work. The Amchitka Island remediation project experience has allowed the DOE to gain valuable insights into how to anticipate and mitigate potential problems associated with future remediation projects. These lessons learned will help the DOE in conducting future work more efficiently, and can also serve as a guide for other agencies performing similar

  19. Research in radiobiology. Annual report of work in progress in the Internal Irradiation Program

    International Nuclear Information System (INIS)

    Survival data on 160 nonirradiated control beagles of the University of Utah's Radiobiology Laboratory were analyzed. The animals died during a period from 1958 into 1979. The average age at death of animals which died during the 1958 to 1965 interval was significantly less than that of those whose deaths occurred in the 1965 to 1979 interval. The best estimate for average age at death for Super-Selected nonirradiated control beagles of the colony is 4864 +- 901 days. The Super-Selected dogs excluded those dying because of epilepsy, lymphosarcoma, lymphoma or accidents, and also excluded all dogs dying before 1966

  20. Research in radiobiology: Annual report of work in progress in the internal irradiation program

    International Nuclear Information System (INIS)

    In the early 1950's the Atomic Energy Commission established at the University of Utah a large, long-term study designed to investigate the toxicity of internally deposited radionuclides in beagles. The first animals were injected on December 1, 1952 and thus began an odyssey unusual in modern science both for its duration and continued scientific interest and relevance. The original dogs were injected with 239Pu and 226Ra. Later, studies were initiated with 241Am, 249Cf, 252Cf, 253Es, 224Ra, 228Ra, 90Sr, and 228Th. These studies were unique and have and will continue to contribute valuable scientific information on the behavior and effects of these substances in biological systems. We feel that the data collected from these studies will be useful for many decades to come as we ask more demanding questions relative to radionuclides and environmental, biological and health issues. While this publication will be the last of our series Research in Radiobiology, the lifespan carcinogenesis studies are continuing under a collaborative arrangement with the I.T.R.I. Beginning in 1988, the colony status tables of dogs in the Utah studies and reports of research by the Radiobiology faculty will be included in the annual I.T.R.I. report. Under our new collaborative arrangements with the I.T.R.I. for the conduct of the lifespan carcinogenesis studies, we expect a continued high level of scientific productivity from our faculty

  1. Basic radiobiology

    International Nuclear Information System (INIS)

    Radiobiology, a branch of science concerned with the action of ionizing radiation on biological tissues and living organisms, is a combination of two disciplines: radiation physics and biology. For use in radiobiology and radiation protection the physical quantity that is useful for defining the quality of an ionizing radiation beam is the linear energy transfer (LET). In contrast to the stopping power, which focuses attention on the energy loss by an energetic charged particle moving through a medium, the LET focuses attention on the linear rate of energy absorption by the absorbing medium as the charged particle traverses the medium. When cells are exposed to ionizing radiation the standard physical effects between radiation and the atoms or molecules of the cells occur first and the possible biological damage to cell functions follows later. The biological effects of radiation result mainly from damage to the DNA, which is the most critical target within the cell; however, there are also other sites in the cell that, when damaged, may lead to cell death

  2. Department of Radiobiology - foreword

    International Nuclear Information System (INIS)

    The research program of the Department of Radiobiology of the Niewodniczanski Institute of Nuclear Physics is performed by two laboratories: 1/Laboratory of Neutron Therapy and Applied in Radiobiology Therapy and Agriculture. 2/ Laboratory of Radiation and Environmental Mutagenesis. The aim of the first mentioned Laboratory is to determine the Relative Biological Effectiveness (RBE) of fast 5.6 MeV neutrons with regard to regime of fractionation. Our goal is to reduce the number of fraction of neutron therapy what makes possible increasing the total dose. The second mentioned Laboratory engages in research on the mutagenesis in rape-seed in vitro regeneration of dihaploids and pollen grains. The object is to find how much fast neutrons, X and γ-rays irradiations stimulate the dihaploide production and to determine their reaction in flower buds microspores and anther cultures. (author)

  3. Cancer radiobiology

    International Nuclear Information System (INIS)

    The work i have done in this dissertation, was mainly aimed at the literature review of radiotherapy radiobiology discussing the cure of tumours with ionizing radiation, from both the biological and physical point of view. The first chapter an introduction about the radiotherapy and includes: definition, working dose, benefit of radiotherapy, risk of radiotherapy, external and internal radiotherapy and treatment planing. In chapter two the theories of radiobiology and main effects caused by the radiation in the interaction with the biological matter were explained, the damages caused by the use of low and high LET (linear energy transfer) particles to mammalian cells were discussed. And discuss a therapeutic advantage may be gained by one of four hypothetical mechanism: repair the damage of DAN, so when sublethal injury can be repaired if no further hits are sustained. Also the reoxygenation of tumor is important for its effects on stabilization of free radicals produced by ionizing radiation. Hypoxic cells generally require an increased dose of radiation for lethal effect, redistribution, within the cell cycle depends on location of cells and their radiosensitivity also cells undergoing DNA synthesis, the S phase, are much more radioresistant than cells in other phase of the cell cycle, and repopulation of tumor cells is indicator of the surviving cells respond by increased regeneration or repopulation. Repopulation is a greater problem with rapidly proliferating tumors than slower growing neoplasms. These mechanisms are known as the classical four R's of radiation biology. One of the important applications of radiobiology is the radiotherapy and cancer treatment, experimental and theoretical studies in radiation biology contribute to the development of radiotherapy, in this dissertation we discussed the dose response relation so as the size of the tumor increases, and the dose needed for local control like wise increases, the risk of injury to normal tissue

  4. Bald eagle nest survey, 1981, Amchitka Island, Alaska

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — A nesting survey for bald eagles Haliaeetus leucocephalus was conducted from May 29, 1981, on a portion of Amchitka Island, Aleutian Islands Unit, Alaska Maritime...

  5. Propagation of Aleutian Canada geese on Amchitka Island, Alaska, 1980

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The methods of propagation on Amchitka Island were changed from past years in that artificial incubation and rearing were abandoned in favor of more natural goose...

  6. The higher fungi of Amchitka and Adak Islands, Alaska

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Fruiting body collections of higher fungi, basidiomycetes and ascomycetes, were made during a twelve day field study on two of Alaska's Aleutian Islands, Amchitka...

  7. Strategy for Long-Term Stewardship and Monitoring of Amchitka Island - 12190

    Energy Technology Data Exchange (ETDEWEB)

    Kautsky, Mark; Nguyen, Jason [U.S. Department of Energy Office of Legacy Management (United States); Darr, Paul S. [S.M. Stoller Corporation (United States); Picel, Mary [Argonne National Laboratory (United States)

    2012-07-01

    The Long-Term Surveillance and Maintenance Plan (LTSMP) for Amchitka details how the U.S. Department of Energy (DOE) intends to fulfill its mission to maintain protection of human health and the environment at and around the sites on Amchitka Island. The LTSMP calls for monitoring to be performed every 5 years, at least in the initial phase of the project. The purpose of the monitoring is to develop a baseline of activity concentrations for selected radionuclides in biota, water, and soil, both on Amchitka and at the reference location on Adak Island, approximately 322 km (200 miles) northeast of Amchitka. Data compiled by the Consortium for Risk Evaluation with Stakeholder Participation (CRESP, 2006) are being included as part of the baseline data set. The specific biological, water, and sediment samples collected during the 2011 sampling event were developed through close coordination with the primary stakeholders, including the Alaska Department of Environmental Conservation, the Aleutian Pribilof Island Association, and the U.S. Fish and Wildlife Service (USFWS). Amchitka is managed by the USFWS as part of the Alaska Maritime National Wildlife Refuge. Two plans were developed to address specific needs of the biological- and the terrestrial-monitoring programs. Results from these monitoring programs will help determine whether the environment is being impacted by radionuclide migration and uptake, and if subsistence and commercial-catch seafood is safe for human consumption. The RESRAD-BIOTA code is being used to evaluate ecological health relative to the radionuclide levels determined from this sampling event. The samples were sent to three laboratories for analysis. With the exception of the seawater samples, most of the samples were sent to the Center for Accelerator Mass Spectrometry at the Lawrence Livermore National Laboratory. A smaller subset of rock-weed samples, Star reindeer lichen samples, and soil samples collected from beneath the lichen were sent

  8. Strategy for Long-Term Stewardship and Monitoring of Amchitka Island - 12190

    International Nuclear Information System (INIS)

    The Long-Term Surveillance and Maintenance Plan (LTSMP) for Amchitka details how the U.S. Department of Energy (DOE) intends to fulfill its mission to maintain protection of human health and the environment at and around the sites on Amchitka Island. The LTSMP calls for monitoring to be performed every 5 years, at least in the initial phase of the project. The purpose of the monitoring is to develop a baseline of activity concentrations for selected radionuclides in biota, water, and soil, both on Amchitka and at the reference location on Adak Island, approximately 322 km (200 miles) northeast of Amchitka. Data compiled by the Consortium for Risk Evaluation with Stakeholder Participation (CRESP, 2006) are being included as part of the baseline data set. The specific biological, water, and sediment samples collected during the 2011 sampling event were developed through close coordination with the primary stakeholders, including the Alaska Department of Environmental Conservation, the Aleutian Pribilof Island Association, and the U.S. Fish and Wildlife Service (USFWS). Amchitka is managed by the USFWS as part of the Alaska Maritime National Wildlife Refuge. Two plans were developed to address specific needs of the biological- and the terrestrial-monitoring programs. Results from these monitoring programs will help determine whether the environment is being impacted by radionuclide migration and uptake, and if subsistence and commercial-catch seafood is safe for human consumption. The RESRAD-BIOTA code is being used to evaluate ecological health relative to the radionuclide levels determined from this sampling event. The samples were sent to three laboratories for analysis. With the exception of the seawater samples, most of the samples were sent to the Center for Accelerator Mass Spectrometry at the Lawrence Livermore National Laboratory. A smaller subset of rock-weed samples, Star reindeer lichen samples, and soil samples collected from beneath the lichen were sent

  9. Amchitka Island, Alaska, Biological Monitoring Report 2011 Sampling Results

    Energy Technology Data Exchange (ETDEWEB)

    None

    2013-09-01

    The Long-Term Surveillance and Maintenance (LTS&M) Plan for the U.S. Department of Energy (DOE) Office of Legacy Management (LM) Amchitka Island sites describes how LM plans to conduct its mission to protect human health and the environment at the three nuclear test sites located on Amchitka Island, Alaska. Amchitka Island, near the western end of the Aleutian Islands, is approximately 1,340 miles west-southwest of Anchorage, Alaska. Amchitka is part of the Aleutian Island Unit of the Alaska Maritime National Wildlife Refuge, which is administered by the U.S. Fish and Wildlife Service (USFWS). Since World War II, Amchitka has been used by multiple U.S. government agencies for various military and research activities. From 1943 to 1950, it was used as a forward air base for the U.S. Armed Forces. During the middle 1960s and early 1970s, the U.S. Department of Defense (DOD) and the U.S. Atomic Energy Commission (AEC) used a portion of the island as a site for underground nuclear tests. During the late 1980s and early 1990s, the U.S. Navy constructed and operated a radar station on the island. Three underground nuclear tests were conducted on Amchitka Island. DOD, in conjunction with AEC, conducted the first nuclear test (named Long Shot) in 1965 to provide data that would improve the United States' capability of detecting underground nuclear explosions. The second nuclear test (Milrow) was a weapons-related test conducted by AEC in 1969 as a means to study the feasibility of detonating a much larger device. Cannikin, the third nuclear test on Amchitka, was a weapons-related test detonated on November 6, 1971. With the exception of small concentrations of tritium detected in surface water shortly after the Long Shot test, radioactive fission products from the tests remain in the subsurface at each test location As a continuation of the environmental monitoring that has taken place on Amchitka Island since before 1965, LM in the summer of 2011 collected biological

  10. Amchitka Island, Alaska, Biological Monitoring Report 2011 Sampling Results

    International Nuclear Information System (INIS)

    The Long-Term Surveillance and Maintenance (LTS&M) Plan for the U.S. Department of Energy (DOE) Office of Legacy Management (LM) Amchitka Island sites describes how LM plans to conduct its mission to protect human health and the environment at the three nuclear test sites located on Amchitka Island, Alaska. Amchitka Island, near the western end of the Aleutian Islands, is approximately 1,340 miles west-southwest of Anchorage, Alaska. Amchitka is part of the Aleutian Island Unit of the Alaska Maritime National Wildlife Refuge, which is administered by the U.S. Fish and Wildlife Service (USFWS). Since World War II, Amchitka has been used by multiple U.S. government agencies for various military and research activities. From 1943 to 1950, it was used as a forward air base for the U.S. Armed Forces. During the middle 1960s and early 1970s, the U.S. Department of Defense (DOD) and the U.S. Atomic Energy Commission (AEC) used a portion of the island as a site for underground nuclear tests. During the late 1980s and early 1990s, the U.S. Navy constructed and operated a radar station on the island. Three underground nuclear tests were conducted on Amchitka Island. DOD, in conjunction with AEC, conducted the first nuclear test (named Long Shot) in 1965 to provide data that would improve the United States' capability of detecting underground nuclear explosions. The second nuclear test (Milrow) was a weapons-related test conducted by AEC in 1969 as a means to study the feasibility of detonating a much larger device. Cannikin, the third nuclear test on Amchitka, was a weapons-related test detonated on November 6, 1971. With the exception of small concentrations of tritium detected in surface water shortly after the Long Shot test, radioactive fission products from the tests remain in the subsurface at each test location As a continuation of the environmental monitoring that has taken place on Amchitka Island since before 1965, LM in the summer of 2011 collected biological and

  11. Radiobiology software for educational purpose

    International Nuclear Information System (INIS)

    To understand radio-nuclide therapy and the basis of radiation protection, it is essential to understand radiobiology. With limited time for classroom teaching and limited time and resources for radiobiology experiments students do not acquire firm grasp of theoretical mathematical models and experimental knowledge of target theory and Linear quadratic models that explain nature of cell survival curves. We believe that this issue might be addressed with numerical simulation of cell survival curves using mathematical models. Existing classroom teaching can be reoriented to understand the subject using the concept of modeling, simulation and virtual experiments. After completion of the lecture, students can practice with simulation tool at their convenient time. In this study we have developed software that can help the students to acquire firm grasp of theoretical and experimental radiobiology. The software was developed using FreeMat ver 4.0, open source software. Target theory, linear quadratic model, cell killing based on Poisson model have been included. The implementation of the program structure was to display the menu for the user choice to be made and then program flows depending on the users choice. The program executes by typing 'Radiobiology' on the command line interface. Students can investigate the effect of radiation dose on cell, interactively. They can practice to draw the cell survival curve based on the input and output data and they can also compare their handmade graphs with automatically generated graphs by the program. This software is in the early stage of development and will evolve on user feedback. We feel this simulation software will be quite useful for students entering in the nuclear medicine, radiology and radiotherapy disciplines. (author)

  12. Basic Radiobiology. Chapter 2

    International Nuclear Information System (INIS)

    Radiobiology is the study (both qualitative and quantitative) of the actions of ionizing radiations on living matter. Since radiation has the ability to cause changes in cells which may later cause them to become malignant, or bring about other detrimental functional changes in irradiated tissues and organs, consideration of the associated radiobiology is important in all diagnostic applications of radiation. Additionally, since radiation can lead directly to cell death, consideration of the radiobiological aspects of cell killing is essential in all types of radiation therapy

  13. Amchitka Island Environmental Analysis at Idaho National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Gracy Elias; W. F. Bauer; J.G. Eisenmenger; C.C. Jensen; B.K. Schuetz; T. C. Sorensen; B.M. White; A. L. Freeman; M. E. McIlwain

    2005-08-01

    The Idaho National Laboratory (INL) provided support to Consortium for Risk Evaluation with Stakeholder Participation (CRESP) in their activities which is supported by the Department of Energy (DOE) to assess the impact of past nuclear testing at Amchitka Island on the ecosystemof the island and surrounding ocean. INL participated in this project in three phases, Phase 1, Phase 2 and Phase 3.

  14. Sea water intrusion model of Amchitka Island, Alaska

    International Nuclear Information System (INIS)

    During the 1960s and 1970s, Amchitka Island, Alaska, was the site of three underground nuclear tests, referred to as Milrow, Long Shot and Cannikin. Amchitka Island is located in the western part of the Aleutian Island chain, Alaska. The groundwater systems affected by the three underground nuclear tests at Amchitka Island are essentially unmonitored because all of the current monitoring wells are too shallow and not appropriately placed to detect migration from the cavities. The dynamics of the island's fresh water-sea water hydrologic system will control contaminant migration from the three event cavities, with migration expected in the direction of the Bering Sea from Long shot and Cannikin and the Pacific Ocean from Milrow. The hydrogeologic setting (actively flowing groundwater system to maintain a freshwater lens) suggests a significant possibility for relatively rapid contaminant migration from these sites, but also presents an opportunity to use projected flowpaths to a monitoring advantage. The purpose of this investigation is to develop a conceptual model of the Amchitka groundwater system and to produce computer model simulations that reflect the boundary conditions and hydraulic properties of the groundwater system. The simulations will be used to assess the validity of the proposed conceptual model and highlight the uncertainties in hydraulic properties of the aquifer. The uncertainties will be quantified by sensitivity analyses on various model parameters. Within the limitations of the conceptual model and the computer simulations, conclusions will be drawn regarding potential radionuclide migration from the three underground nuclear tests

  15. Radiobiological Research in JINR

    CERN Document Server

    Krasavin, E A

    2000-01-01

    The results of long-term radiobiological and radiation-genetical research in DRRR (Division of Radiobiology) are summarized. The different radiation-induced effects in bacteria, yeasts, mammalian and human cells after irradiation by gamma-rays and heavy charged particles are considered. The important role of DNA repair processes in biological effectiveness of different types of radiation were shown. The data on mutagenic action of such kinds of radiation on pro- and eukaryotic cells were analyzed. On the basis of our data the hypersensitivity of human and mammalian chromosomes after low doses of gamma-rays (10-20 sGy) was revealed. The radiobiological effect of ^{211}At - methylene blue complex on human melanoma cells was studied. The extremely high effectiveness of this complex on melanoma cells was shown.

  16. Remedial Action Work Plan Amchitka Island Mud Pit Closures

    Energy Technology Data Exchange (ETDEWEB)

    DOE/NV

    2001-04-05

    This remedial action work plan presents the project organization and construction procedures developed for the performance of the remedial actions at U.S. Department of Energy (DOE's) sites on Amchitka Island, Alaska. During the late1960s and early 1970s, the U.S. Department of Defense and the U.S. Atomic Energy Commission (the predecessor agency to DOE) used Amchitka Island as a site for underground nuclear tests. A total of nine sites on the Island were considered for nuclear testing; however, tests were only conducted at three sites (i.e., Long Shot in 1965, Milrow in 1969, and Cannikin in 1971). In addition to these three sites, large diameter emplacement holes were drilled in two other locations (Sites D and F) and an exploratory hole was in a third location (Site E). It was estimated that approximately 195 acres were disturbed by drilling or preparation for drilling in conjunction with these activities. The disturbed areas include access roads, spoil-disposal areas, mud pits which have impacted the environment, and an underground storage tank at the hot mix plant which was used to support asphalt-paving operations on the island. The remedial action objective for Amchitka Island is to eliminate human and ecological exposure to contaminants by capping drilling mud pits, removing the tank contents, and closing the tank in place. The remedial actions will meet State of Alaska regulations, U.S. Fish and Wildlife Service refuge management goals, address stakeholder concerns, and address the cultural beliefs and practices of the native people. The U.S. Department of Energy, Nevada Operations Office will conduct work on Amchitka Island under the authority of the Comprehensive Emergency Response, Compensation, and Liability Act. Field activities are scheduled to take place May through September 2001. The results of these activities will be presented in a subsequent Closure Report.

  17. Research in Radiobiology

    International Nuclear Information System (INIS)

    This document contains the tables of contents for the reports published by the University of Utah Radiobiology Laboratory from 1953--1987. Also included is a keyword index for the reports, and references for all books, book and symposia chapters and journal article published by Laboratory staff between 1950 and 1988

  18. With the Radiobiology Group

    CERN Multimedia

    1980-01-01

    The Radiobiology Group carries out experiments to study the effect of radiation on living cells. The photo shows the apparatus for growing broad beans which have been irradiated by 250 GeV protons. The roots are immersed in a tank of running water (CERN Weekly Bulletin 26 January 1981 and Annual Report 1980 p. 160). Karen Panman, Marilena Streit-Bianchi, Roger Paris.

  19. Record of Decision for Amchitka Surface Closure, Alaska

    Energy Technology Data Exchange (ETDEWEB)

    None

    2008-08-01

    This Record of Decision has been prepared to document the remedial actions taken on Amchitka Island to stabilize contaminants associated with drilling mud pits generated as a result of nuclear testing operations conducted on the island. This document has been prepared in accordance with the recommended outline in the Alaska Department of Environmental Conservation guidance on decision documentation under the Site Cleanup Rules (18 AAC 75.325-18 AAC 75.390) (ADEC 1999). It also describes the decision-making process used to establish the remedial action plans and defines the associated human health and ecological risks for the remediation.

  20. Record of Decision for Amchitka Surface Closure, Alaska

    International Nuclear Information System (INIS)

    This Record of Decision has been prepared to document the remedial actions taken on Amchitka Island to stabilize contaminants associated with drilling mud pits generated as a result of nuclear testing operations conducted on the island. This document has been prepared in accordance with the recommended outline in the Alaska Department of Environmental Conservation guidance on decision documentation under the Site Cleanup Rules (18 AAC 75.325-18 AAC 75.390) (ADEC 1999). It also describes the decision-making process used to establish the remedial action plans and defines the associated human health and ecological risks for the remediation.

  1. Sea otter investigation, Amchitka Island, 1954, and proposed plan of research for sea otters

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report describes a sea otter investigation on Amchitka Island during 1954 and a proposed plan of research for sea otters. The report covers capturing wild sea...

  2. Preliminary report on the avian ecology of Amchitka Islands, June 1967

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The avifauna of Amchitka Island was surveyed during June, 1967, in order to: form a basis for predicting the nature and magnitude of effects on the bird population...

  3. 1980 raptor survey: The breeding peregrine falcon (Falco peregrinus) population of Amchitka Island, Alaska

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — A survey of the breeding peregrine falcon (Falco peregrinus) population was made on Amchitka Island, Alaska, during the 1980 summer field season. The survey was...

  4. Radiation Protection Research: Radiobiology

    International Nuclear Information System (INIS)

    The main objectives of research in the field of radiobiology and epidemiology performed at the Belgian Nuclear Research Centre SCK-CEN are (1) to study cancer mortality in nuclear workers in Belgium; to document the feasibility of retrospective cohort studies in Belgium; (2) to participate in the IARC study; (3) to elucidate the molecular basis of the effects of ionising radiation in the mammalian embryo during the early phases of its development; (4) to assess the genetic risk of maternal exposure to ionizing radiation; (5) to elucidate the cellular mechanisms leading to brain damage after prenatal irradiation; (6) to advise authorities and to provide the general population with adequate information concerning the health risk arising from radiation exposure. Progress and major achievements in these topical areas in 1999 are reported

  5. Non-extensive radiobiology

    Science.gov (United States)

    Sotolongo-Grau, O.; Rodriguez-Perez, D.; Antoranz, J. C.; Sotolongo-Costa, O.

    2011-03-01

    The expression of survival factors for radiation damaged cells is based on probabilistic assumptions and experimentally fitted for each tumor, radiation and conditions. Here we show how the simplest of these radiobiological models can be derived from the maximum entropy principle of the classical Boltzmann-Gibbs expression. We extend this derivation using the Tsallis entropy and a cutoff hypothesis, motivated by clinical observations. A generalization of the exponential, the logarithm and the product to a non-extensive framework, provides a simple formula for the survival fraction corresponding to the application of several radiation doses on a living tissue. The obtained expression shows a remarkable agreement with the experimental data found in the literature, also providing a new interpretation of some of the parameters introduced anew. It is also shown how the presented formalism may have direct application in radiotherapy treatment optimization through the definition of the potential effect difference, simply calculated between the tumour and the surrounding tissue.

  6. Radiation Protection Research: Radiobiology

    Energy Technology Data Exchange (ETDEWEB)

    Desaintes, C

    2000-07-01

    The main objectives of research in the field of radiobiology and epidemiology performed at the Belgian Nuclear Research Centre SCK-CEN are (1) to study cancer mortality in nuclear workers in Belgium; to document the feasibility of retrospective cohort studies in Belgium; (2) to participate in the IARC study; (3) to elucidate the molecular basis of the effects of ionising radiation in the mammalian embryo during the early phases of its development; (4) to assess the genetic risk of maternal exposure to ionizing radiation; (5) to elucidate the cellular mechanisms leading to brain damage after prenatal irradiation; (6) to advise authorities and to provide the general population with adequate information concerning the health risk arising from radiation exposure. Progress and major achievements in these topical areas in 1999 are reported.

  7. Toward a national consensus: teaching radiobiology to radiation oncology residents

    International Nuclear Information System (INIS)

    Purpose: The ASTRO Joint Working Group on Radiobiology Teaching, a committee composed of members having affiliations with several national radiation oncology and biology-related societies and organizations, commissioned a survey designed to address issues of manpower, curriculum standardization, and instructor feedback as they relate to resident training in radiation biology. Methods and Materials: Radiation biology instructors at U.S. radiation oncology training programs were identified and asked to respond to a comprehensive electronic questionnaire dealing with instructor educational background, radiation biology course content, and sources of feedback with respect to curriculum planning and resident performance on standardized radiation biology examinations. Results: Eighty-five radiation biology instructors were identified, representing 73 radiation oncology residency training programs. A total of 52 analyzable responses to the questionnaire were received, corresponding to a response rate of 61.2%. Conclusion: There is a decreasing supply of instructors qualified to teach classic, and to some extent, clinical, radiobiology to radiation oncology residents. Additionally, those instructors with classic training in radiobiology are less likely to be comfortable teaching cancer molecular biology or other topics in cancer biology. Thus, a gap exists in teaching the whole complement of cancer and radiobiology curricula, particularly in those programs in which the sole responsibility for teaching falls to one faculty member (50% of training programs are in this category). On average, the percentage of total teaching time devoted to classic radiobiology (50%), clinical radiobiology (30%), and molecular and cancer biology (20%) is appropriate, relative to the current makeup of the board examination. Nevertheless large variability exists between training programs with respect to the total number of contact hours per complete radiobiology course (ranging from

  8. Radiobiology and Epidemiology

    Energy Technology Data Exchange (ETDEWEB)

    Desaintes, C; Holmstock, L

    2001-04-01

    The main objectives of research in the field of radiobiology and epidemiology performed at the Belgian Nuclear Research Centre SCK-CEN are: (1) to study cancer mortality in nuclear workers in Belgium and to co-ordinate the Belgian contribution to the 'International Collaborative Study of Cancer Risk among Radiation Workers in the Nuclear Industry'; (2) to elucidate the molecular basis of individual susceptibility to ionizing radiation in mammalian embryo during the early phases of its development; (3) to assess the genetic risk of maternal exposure to ionizing radiation; (4) to elucidate the cellular mechanisms leading to brain damage after prenatal irradiation; (5) to monitor the early variations of gene expression induced by ionising radiation and cytokines; (6) to evaluate the use of cytokines and natural substances for improving radiotherapy protocols; (6) to advise authorities and to provide the general population with adequate information concerning the health risk arising from radiation exposure. Progress and major achievements in these topical areas in 2000 are reported.

  9. Radiobiology and Epidemiology

    International Nuclear Information System (INIS)

    The main objectives of research in the field of radiobiology and epidemiology performed at the Belgian Nuclear Research Centre SCK-CEN are: (1) to study cancer mortality in nuclear workers in Belgium and to co-ordinate the Belgian contribution to the 'International Collaborative Study of Cancer Risk among Radiation Workers in the Nuclear Industry'; (2) to elucidate the molecular basis of individual susceptibility to ionizing radiation in mammalian embryo during the early phases of its development; (3) to assess the genetic risk of maternal exposure to ionizing radiation; (4) to elucidate the cellular mechanisms leading to brain damage after prenatal irradiation; (5) to monitor the early variations of gene expression induced by ionising radiation and cytokines; (6) to evaluate the use of cytokines and natural substances for improving radiotherapy protocols; (6) to advise authorities and to provide the general population with adequate information concerning the health risk arising from radiation exposure. Progress and major achievements in these topical areas in 2000 are reported

  10. Radiobiology and isotopic imaging

    International Nuclear Information System (INIS)

    This 6. workshop occurs after more than 10 years of meaningful scientific exchanges between the National Institute of Radiological Sciences and the Life Science Division of the French Atomic Commission. The aim of the workshops held alternatively in Japan and France every two years is to promote new collaboration and stimulate exchange of scientists. In this respect, encouraging results have been obtained, since young scientists are currently working at the partner's institution; this is highlighted this year, with the presentation of their results as speakers from each country. New projects are under way to enlarge scientific collaboration. This sixth workshop will allocate three days to specialized working groups within the laboratories at the various locations of the Life Science Division. We hope that all participants will take this opportunity to develop further collaborative research activities in connection with the recent major advances in the field of radiobiology and medical imaging. Such a meeting appears of high interest within the context of new nuclear energy developments

  11. VI Congress on radiation research (radiobiology, radioecology, radiation safety). Abstracts. Volume 2 (sections VIII-XIV)

    International Nuclear Information System (INIS)

    The collection contains abstracts at the VI Congress on radiation research, in which program is included various aspects of ionizing and non-ionizing radiations on living organisms, problems of radioecology and radiation safety of humans and the environment. The Congress is dedicated to the 25th anniversary of the Chernobyl accident . Several reports have summarized the 25-year study of the effects of the accident, formulated forecasts and the main directions of further research. The second volume includes reports in sections : radioecology, combined effect of radiation and other environmental factors, agricultural radioecology, radiobiology of heavy ions, theoretical problems of radiobiology, systematic radiobiology. Radiobiology of non-ionizing radiation, biological effects, electromagnetic safety and regulation, radiobiological and radioecological education are discussed

  12. Microirradiation techniques in radiobiological research

    Indian Academy of Sciences (India)

    Guido A Drexler; Miguel J Ruiz-Gómez

    2015-09-01

    The aim of this work is to review the uses of laser microirradiation and ion microbeam techniques within the scope of radiobiological research. Laser microirradiation techniques can be used for many different purposes. In a specific condition, through the use of pulsed lasers, cell lysis can be produced for subsequent separation of different analytes. Microsurgery allows for the identification and isolation of tissue sections, single cells and subcellular components, using different types of lasers. The generation of different types of DNA damage, via this type of microirradiation, allows for the investigation of DNA dynamics. Ion microbeams are important tools in radiobiological research. There are only a limited number of facilities worldwide where radiobiological experiments can be performed. In the beginning, research was mostly focused on the bystander effect. Nowadays, with more sophisticated molecular and cellular biological techniques, ion microirradiation is used to unravel molecular processes in the field of radiobiology. These include DNA repair protein kinetics or chromatin modifications at the site of DNA damage. With the increasing relevance of charged particles in tumour therapy and new concepts on how to generate them, ion microbeam facilities are able to address unresolved questions concerning particle tumour therapy.

  13. Radiotherapy treatment planning linear-quadratic radiobiology

    CERN Document Server

    Chapman, J Donald

    2015-01-01

    Understand Quantitative Radiobiology from a Radiation Biophysics PerspectiveIn the field of radiobiology, the linear-quadratic (LQ) equation has become the standard for defining radiation-induced cell killing. Radiotherapy Treatment Planning: Linear-Quadratic Radiobiology describes tumor cell inactivation from a radiation physics perspective and offers appropriate LQ parameters for modeling tumor and normal tissue responses.Explore the Latest Cell Killing Numbers for Defining Iso-Effective Cancer TreatmentsThe book compil

  14. BNL ACCELERATOR-BASED RADIOBIOLOGY FACILITIES

    Energy Technology Data Exchange (ETDEWEB)

    LOWENSTEIN,D.I.

    2000-05-28

    For the past several years, the Alternating Gradient Synchrotron (AGS) at Brookhaven National Laboratory (USA) has provided ions of iron, silicon and gold, at energies from 600 MeV/nucleon to 10 GeV/nucleon, for the US National Aeronautics and Space Administration (NASA) radiobiology research program. NASA has recently funded the construction of a new dedicated ion facility, the Booster Applications Facility (BAF). The Booster synchrotron will supply ion beams ranging from protons to gold, in an energy range from 40--3,000 MeV/nucleon with maximum beam intensities of 10{sup 10} to 10{sup 11} ions per pulse. The BAF Project is described and the future AGS and BAF operation plans are presented.

  15. The European Radiobiology Archives (ERA), its present status, relation to other radiobiology archives and future development

    International Nuclear Information System (INIS)

    The European Radiobiology Archives (ERA) in cooperation with the US (National Radiobiology Archives, NRA) and Japanese (Japanese Radiobiology Archives, JRA) aim to collect most of the information still available in Europe on long-term animal experiments - including some selected human studies suitable for comparison with animal data - and to make them available to the scientific community for further analysis. Presently, the archives contain a description of the exposure conditions, animal strains, etc from ∝350.000 individuals, and data on survival and pathology are available from ∝200.000 individuals. These data are incorporated in an ACCESS 2000 database, which also includes means (forms with underlying computer code) for browsing through the data, searching for groups given certain treatments, using specific animal strains or age, etc. Other forms allow the selection of experimental groups, their evaluation by some statistical programs and their export for further detailed studies by interested scientists. The forms also allow researchers to combine groups and to pool diseases into larger classes, e.g. all malignant tumours, all lung tumours etc., features that are important when studies from different laboratories are to be evaluated. The use of the database is illustrated by an example on the selection and preparation for further analysis of data dealing with the effects of 224Ra. The collection of data will continue in the future; and the archives will liase with similar ventures such as the European 'pathbase'. The user interface will be developed further for accessibility and user friendliness and be continuously adjusted to the current state of the art of hardware and software. The archives are to be transferred to the Bundesamt fuer Strahlenschutz (BfS), Neuherberg, Germany under the sponsorship of the European Commission and in collaboration with the European Late Effect Project Group (EULEP). (orig.)

  16. Screening Risk Assessment for Possible Radionuclides in the Amchitka Marine Environment

    Energy Technology Data Exchange (ETDEWEB)

    NNSA/NV

    2002-10-31

    As part of its environmental stewardship program the U.S. Department of Energy (DOE) is reevaluating three sites where underground nuclear tests were conducted in the deep subsurface of Amchitka Island, Alaska. The tests (i.e., Long Shot, Milrow, and Cannikin) were conducted in 1965, 1969, and 1971, respectively. Extensive investigations were conducted on these tests and their effect on the environment. Evaluations at the time of testing indicated limited release of radionuclides and absence of risk related to the testing; however, these are being reevaluated under the current DOE environmental stewardship program. A screening risk assessment of potential radionuclide release into the marine environment is an important part of this reevaluation. The risk assessment is one of three interrelated activities: a groundwater model and this screening risk assessment, both of which guide the decisions in the third activity, the site closure plan. Thus, the overall objective of the work is to understand, and subsequently manage, any risk to humans and the environment through a closure and long-term stewardship plan. The objective of this screening risk assessment is to predict whether possible releases of radionuclides at the ocean floor would represent potential risks to Native Alaskans by consumption of marine subsistence species. In addition, risks were predicted for consumers of commercial catches of marine organisms. These risks were calculated beginning with estimates of possible radionuclide release at the seafloor (from a groundwater modeling study), into the seawater, through possible uptake by marine organisms, and finally possible consumption by humans. The risk assessment model has 11 elements, progressing from potential release at the seafloor through water and food chains to human intake. Data for each of these elements were systematically found and synthesized from many sources, and represent the best available knowledge. Whenever precise data were lacking

  17. Radiobiology

    International Nuclear Information System (INIS)

    The effects of metridazole and nitroimidazole on the survival time of cultured hamster cells following exposure to various doses and dose rates of 60Co γ radiation or neutrons were studied. Both were found to increase the radiosensitivity of the cells. Data are included on the modifying effects of neutron spectra, energy levels, LET, OER, dose, and dose fractionation schedules on the γ and neutron sensitivity of cultured hamster cells. Studies on the sensitivity of cultured hamster cells and normal liver and hepatoma cells to hyperthermia and hypoxia, with and without the added effects of x irradiation showed that heat treatment at 430C enhanced the radiosensitivity of the cells, with hypoxic cells being the most sensitive. A system was developed for the study of radioinduced carcinogenesis in cultured hamster embryo cells. Preliminary data are presented on the dose response relationships for transformation following exposure to x radiation or neutrons. (U.S.)

  18. Verification and Uncertainty Reduction of Amchitka Underground Nuclear Testing Models

    Energy Technology Data Exchange (ETDEWEB)

    Ahmed Hassan; Jenny Chapman

    2006-02-01

    The modeling of Amchitka underground nuclear tests conducted in 2002 is verified and uncertainty in model input parameters, as well as predictions, has been reduced using newly collected data obtained by the summer 2004 field expedition of CRESP. Newly collected data that pertain to the groundwater model include magnetotelluric (MT) surveys conducted on the island to determine the subsurface salinity and porosity structure of the subsurface, and bathymetric surveys to determine the bathymetric maps of the areas offshore from the Long Shot and Cannikin Sites. Analysis and interpretation of the MT data yielded information on the location of the transition zone, and porosity profiles showing porosity values decaying with depth. These new data sets are used to verify the original model in terms of model parameters, model structure, and model output verification. In addition, by using the new data along with the existing data (chemistry and head data), the uncertainty in model input and output is decreased by conditioning on all the available data. A Markov Chain Monte Carlo (MCMC) approach is adapted for developing new input parameter distributions conditioned on prior knowledge and new data. The MCMC approach is a form of Bayesian conditioning that is constructed in such a way that it produces samples of the model parameters that eventually converge to a stationary posterior distribution. The Bayesian MCMC approach enhances probabilistic assessment. Instead of simply propagating uncertainty forward from input parameters into model predictions (i.e., traditional Monte Carlo approach), MCMC propagates uncertainty backward from data onto parameters, and then forward from parameters into predictions. Comparisons between new data and the original model, and conditioning on all available data using MCMC method, yield the following results and conclusions: (1) Model structure is verified at Long Shot and Cannikin where the high-resolution bathymetric data collected by CRESP

  19. Radiobiological comparison of pions and heavy ions

    International Nuclear Information System (INIS)

    The physical and radiobiological differences between some aspects of pions and heavy ions are discussed, followed by a discussion of acute and late effects of high LET radiations compared to low LET radiations

  20. Fundamental aspects of LET in radiobiology

    International Nuclear Information System (INIS)

    Some of the radiobiological features of radiation studies using radiations with different distributions of LET or y have been discussed, with emphasis on the areas of doubt. A considerable amount of data can be explained reasonably well, but some very basic questions remain unanswered, such as how much radiation injury is due to damage to DNA and why does OER go down as LET rises. Further studies using radiations of different LET are essential to help solve basic problems in radiobiology

  1. Radiobiology and radiation protection. Recent developments and future trends in radiobiology

    International Nuclear Information System (INIS)

    The 28th annual meeting of the Fachverband fuer Strahlenschutz, held from October 23 - 25, 1996 in Hannover, discussed the various aspects of the leading theme, radiation protection and radiobiology, recent developments and future trends in radiobiology. The papers presented in the proceedings volume address the three main aspects: (1) Mechanisms of the radiation effects - molecular and cellular mechanisms, genetic and prenatal radiation effects, cancerogenesis and mutagenesis; (2) Novel methods in radiobiology research: microdosimetry from the biological angle, novel methods in molecular biology including computerized simulation of DNA, methods of biological dosimetry, radiobiological aspects of neutrons and other densely ionizing radiation (Pt, Rn); (3) Knowledge and concepts for radiological protection: individual radiosensitivity, radiobiological aspects in medical applications of ionizing radiation, accidents in industry, radiation exposure in aeronautics and astronautics. (vhe)

  2. Subsurface Completion Report for Amchitka Underground Nuclear Test Sites: Long Shot, Milrow, and Cannikin, Rev. No.: 1

    Energy Technology Data Exchange (ETDEWEB)

    Echelard, Tim

    2006-09-01

    Three underground nuclear tests were conducted on Amchitka Island, Alaska, in 1965, 1969, and 1971. The effects of the Long Shot, Milrow, and Cannikin tests on the environment were extensively investigated during and following the detonations, and the area continues to be monitored today. This report is intended to document the basis for the Amchitka Underground Nuclear Test Sites: Long Shot, Milrow, and Cannikin (hereafter referred to as ''Amchitka Site'') subsurface completion recommendation of No Further Remedial Action Planned with Long-Term Surveillance and Maintenance, and define the long-term surveillance and maintenance strategy for the subsurface. A number of factors were considered in evaluating and selecting this recommendation for the Amchitka Site. Historical studies and monitoring data, ongoing monitoring data, the results of groundwater modeling, and the results of an independent stakeholder-guided scientific investigation were also considered in deciding the completion action. Water sampling during and following the testing showed no indication that radionuclides were released to the near surface, or marine environment with the exception of tritium, krypton-85, and iodine-131 found in the immediate vicinity of Long Shot surface ground zero. One year after Long Shot, only tritium was detectable (Merritt and Fuller, 1977). These tritium levels, which were routinely monitored and have continued to decline since the test, are above background levels but well below the current safe drinking water standard. There are currently no feasible means to contain or remove radionuclides in or around the test cavities beneath the sites. Surface remediation was conducted in 2001. Eleven drilling mud pits associated with the Long Shot, Milrow and Cannikin sites were remediated. Ten pits were remediated by stabilizing the contaminants and constructing an impermeable cap over each pit. One pit was remediated by removing all of the contaminated mud

  3. Amchitka Island, Alaska, Potential U.S. Department of Energy Site Responsibilities

    Energy Technology Data Exchange (ETDEWEB)

    U.S. Department of Energy, Nevada Operations Office

    1999-01-22

    This historical records review report concerns the activities of the US Atomic Energy Commission (AEC) at Amchitka Island, Alaska, over a period extending from 1942 to 1993. The report focuses on AEC activities resulting in known or suspected contamination of the island environment by nonradiological hazardous or toxic materials as discerned through historical records. In addition, the information from historical records was augmented by an August 1998 sampling event. Both the records review and sampling were conducted by IT Corporation on behalf of the US Department of Energy (DOE), the predecessor agency to the AEC. The intent of this investigation was to identify all potentially contaminated sites for which DOE may be responsible, wholly or partially, including all official sites of concern as recognized by the US Fish and Wildlife Service (USFWS). Additionally, potential data gaps that the DOE will need to fill to support the ecological and human health risk assessments performed were identified. A review of the available historical information regarding AEC's activities on Amchitka Island indicates that the DOE is potentially responsible for 11 sites identified by USFWS and an additional 10 sites that are not included in the USFWS database of sites of potential concern.

  4. Radiobiological effects of metallic nanoparticles

    International Nuclear Information System (INIS)

    Full text: Radiobiological effects of nanoparticles and its cellular mechanism in normal tissue regeneration are investigated. About 2 nm diameter gold nanoaprticies are used in this study with bovine endothelial eells as normal cells and glioma type cells. The imtdiation was conducted using Spring8 synchrotron in Japan and the cell culture studies were performed at the school of Medical Sciences RMIT-University. AuNPs accelerate eells migration esp cially normal endothelial cells. This effect has been observed when AuNPs are introduced into the cells and the cells impregnated with AuNPs migrate faster than the ones without AuNPs. The cells with AuNPs have been found to fill in gaps created in cultures about five times faster than those without AuNPs. The effects have been observed with gaps generated by radiations or when such gaps are made by scratehes 'wounds'. Filling of artificial scratch have been found to be much faster than radiation created gaps. Two aspects of this phenomenon are given; one is biology based where it is thought of disrupts caused by such particles to the cells eytoskeleton org nisation and hence induces different chemical pathways promoting cells motility. The other reason (physics) can be due to Coulomb repulsion force generated by polarised cells pushing the cells into gaps and also cell-polarisation could lead into cells symmetr breaking hence accelerating their motion. Conclusion Radiotherapy treatment efficiency can be improve by using AuNps where dose can be enhance to kill the tumour cells and at the same time helping normal cells to regenerate.

  5. National Radiobiology Archives distributed access programmer's guide

    International Nuclear Information System (INIS)

    The National Radiobiology Archives is a comprehensive effort to gather, organize, and catalog original data, representative specimens, and supporting materials related to significant radiobiology studies. This provides researchers with information for analyses which compare or combine results of these and other studies and with materials for analysis by advanced molecular biology techniques. This Programmer's Guide document describes the database access software, NRADEMO, and the subset loading script NRADEMO/MAINT/MAINTAIN, which comprise the National Laboratory Archives Distributed Access Package. The guide is intended for use by an experienced database management specialist. It contains information about the physical and logical organization of the software and data files. It also contains printouts of all the scripts and associated batch processing files. It is part of a suite of documents published by the National Radiobiology Archives

  6. Collaboration versus communication: The Department of Energy's Amchitka Island and the Aleut Community

    International Nuclear Information System (INIS)

    Increasingly managers and scientists are recognizing that solving environmental problems requires the inclusion of a wide range of disciplines, governmental agencies, Native American tribes, and other stakeholders. Usually such inclusion involves communication at the problem-formulation phase, and at the end to report findings. This paper examines participatory research, the differences between the traditional stakeholder involvement method of communication (often one-way, at the beginning and the end), compared to full collaboration, where parties are actively involved in the scientific process. Using the Department of Energy's (DOE) Amchitka Island in the Aleutians as a case study, we demonstrate that the inclusion of Aleut people throughout the process resulted in science that was relevant not only to the agency's needs and to the interested and affected parties, but that led to a solution. Amchitka Island was the site of three underground nuclear tests from 1965 to 1971, and virtually no testing of radionuclide levels in biota, subsistence foods, or commercial fish was conducted after the 1970s. When DOE announced plans to close Amchitka, terminating its managerial responsibility, without any further testing of radionuclide levels in biota, there was considerable controversy, which resulted in the development of a Science Plan to assess the potential risks to the marine environment from the tests. The Consortium for Risk Evaluation with Stakeholder Participation (CRESP) was the principle entity that developed and executed the science plan. Unlike traditional science, CRESP embarked on a process to include the Alaskan Natives of the Aleutian Islands (Aleuts), relevant state and federal agencies, and other stakeholders at every phase. Aleuts were included in the problem-formulation, research design refinement, the research, analysis of data, dissemination of research findings, and public communication. This led to agreement with the results, and to developing a

  7. Evolution of radiobiological models in radiation oncology

    International Nuclear Information System (INIS)

    Predicting treatment outcome to radiotherapy from in-vitro radiobiological parameters and utilizing the BED approach helps to tailor individual patient treatments and design new promising treatment protocols for patients in whom unfavorable treatment outcome is anticipated. This paper presents the present status of the LQ model of dose effect relationship

  8. National Radiobiology Archives Distributed Access user's manual

    International Nuclear Information System (INIS)

    This User's Manual describes installation and use of the National Radiobiology Archives (NRA) Distributed Access package. The package consists of a distributed subset of information representative of the NRA databases and database access software which provide an introduction to the scope and style of the NRA Information Systems

  9. Soft x rays for radiobiological studies

    International Nuclear Information System (INIS)

    Lethal effects and chromosome aberrations induced in cells exposed to low energy (soft) X rays demonstrated that these relatively low energy X rays are just as effective as those of higher energy for radiobiological studies, and even more effective for irradiating cultured mammalian cells than laboratory animals. (author)

  10. Radiobiological and clinical aspects of neutron therapy

    International Nuclear Information System (INIS)

    Radiobiological investigations and their interpretation are discussed. The history of neutrontherapy, the results of RBE-investigations in man as well as clinical results are given. The hypothesis on reaction of human tissue and tumours towards neutron irradiation is presented. (A.S.)

  11. Human Health and Ecological Risk Assessment Work Plan Mud Pit Release Sites, Amchitka Island, Alaska

    Energy Technology Data Exchange (ETDEWEB)

    DOE/NV

    2001-03-12

    This Work Plan describes the approach that will be used to conduct human health and ecological risk assessments for Amchitka Island, Alaska, which was utilized as an underground nuclear test site between 1965 and 1971. During this period, the U.S. Atomic Energy Commission (now the U.S. Department of Energy) conducted two nuclear tests (known as Long Shot and Milrow) and assisted the U.S. Department of Defense with a third test (known as Cannikin). Amchitka Island is approximately 42 miles long and located 1,340 miles west-southwest of Anchorage, Alaska, in the western end of the Aleutian Island archipelago in a group of islands known as the Rat Islands. Historically including deep drilling operations required large volumes of drilling mud, a considerable amount of which was left on the island in exposed mud pits after testing was completed. Therefore, there is a need for drilling mud pit remediation and risk assessment of historical mud pit releases. The scope of this work plan is to document the environmental objectives and the proposed technical site investigation strategies that will be utilized for the site characterization of the constituents in soil, surface water, and sediment at these former testing sites. Its goal is the collection of data in sufficient quantity and quality to determine current site conditions, support a risk assessment for the site surfaces, and evaluate what further remedial action is required to achieve permanent closure of these three sites that will protect both human health and the environment. Suspected compounds of potential ecological concern for investigative analysis at these sites include diesel-range organics, polyaromatic hydrocarbons, polychlorinated biphenyls, volatile organic compounds, and chromium. The results of these characterizations and risk assessments will be used to evaluate corrective action alternatives to include no further action, the implementation of institutional controls, capping on site, or off-sit e

  12. Workshop on radiobiological effectiveness of neutrons

    International Nuclear Information System (INIS)

    The radiobiological effectiveness (RBE) of neutrons has become the subject of some heated discussions in both scientific and radiation-protection oriented communities. This has become especially so since the realization that neutron exposures of A-bomb survivors in Hiroshima were considerably lower than previously assumed, thus ''devaluating'' the importance of what we thought was a solid human data base. At the same time, more recent data from radiobiological research appeared to indicate that, at least for some biological endpoints, the RBE of neutrons at low doses and low dose rates was increased dramatically compared to the RBE at higher dose and dose rates. As a consequence, the protection of health against neutrons became a subject of some urgency. The objective of this workshop was to evaluate the existing data base in order to determine the need for additional research in this field. 22 refs., 3 figs., 6 tabs

  13. The Fundamentals of Imaging Physics and Radiobiology

    CERN Document Server

    Selman, Joseph

    2000-01-01

    Like its well-known predecessor, this new and expanded Ninth Edition presents numerous important changes, beginning with the title and continuing throughout the text. Drawing on current knowledge and his own extensive experience, Dr. Selman provides a thorough revision and overview of each previously included chapter. Definitions, foundations, and principles are presented along with changes in methods and procedures. The text presents five new chapters on computed tomography, radioactivity and diagnostic nuclear medicine, radiobiology, protection in radiology/health physics, and nonradiologic

  14. Scientific projection paper for space radiobiological research

    International Nuclear Information System (INIS)

    A nationale for the radiobiological research requirements for space is rooted in a national commitment to the exploration of space, mandated in the form of the National Space Act. This research is almost entirely centered on man; more specifically, on the effects of the space radiation environment on man and his protection from them. The research needs discussed in this presentation include the space radiation environment; dosimetry; radiation biology-high LET particles (dose/response); and operational countermeasures

  15. Radiobiological models of normal tissue reactions

    International Nuclear Information System (INIS)

    Purpose: The present review summarizes radiobiological models of normal tissue responses to radiation and their consequences for potential therapeutic interventions. Material and Methods: Common radiobiological principles and pathogenetic models can be established for classes of tissues. These models may support the development of general modalities, both therapeutic and supportive, for the modulation of these responses. Results: The stem cell concept, based on studies in standard tissue culture, describes the clonogenic survival after radiation treatment. The factors affecting cell survival are summarized as the 4 Rs of radiotherapy. Based on the stem cell concept, the reactions of normal tissue to ionising radiation were considered a consequence exclusively of the proliferative sterilisation of cells of a given target cell population. Once stem cells are inactivated, responses develop in a passive manner. However, recent studies into the pathogenesis of radiation tissue injury have clearly shown that numerous postirradiation events occur during the symptom-free latent time in irradiated cells and tissues, which modulate the manifestation of damage. These are summarized by models of tissue radiation pathology. Conclusions: Cellular radiobiology and the tissue models based on the stem cell concept assume that exclusively the sterilisation of target cells is the radiation effect which results in both acute and late tissue responses. As a consequence, the radiation sensitivity can only be modulated by modification of radiobiological parameters at the time of irradiation, while at later time points only symptomatic treatment can be applied. Tissue radiation pathology, in contrast, allows for post-irradiation modification of the manifestation of radiation sequelae in tissues. (orig.)

  16. Dosimetry for radiobiology experiments at GANIL

    Science.gov (United States)

    Durantel, Florent; Balanzat, Emmanuel; Cassimi, Amine; Chevalier, François; Ngono-Ravache, Yvette; Madi, Toiammou; Poully, Jean-Christophe; Ramillon, Jean-Marc; Rothard, Hermann; Ropars, Frédéric; Schwob, Lucas; Testard, Isabelle; Saintigny, Yannick

    2016-04-01

    Mainly encouraged by the increasing application of ion beams for cancer treatment (hadron-therapy) including carbon beams, the use of heavy ion facilities for radiobiology is expanding rapidly today. As an alternative to dedicated centers for treatment and medical research, accelerators like GANIL offer the possibility to undertake such experiments. Since 20 years, CIMAP, reinforced 15 years ago by the biological host laboratory LARIA, has been receiving researchers in radiobiology and assisted them in performing experiments in different fields such as hadron-therapy, space radioprotection and fundamental biological and physico-chemical mechanisms. We present here a short description of the beam line and the on-line equipments that allow the automatic irradiation of up to 24 biological samples at once. We also developed an original on-line beam monitoring procedure for low ion flux (low dose rates) based on the measurement of the K-shell X-rays emitted from a thin iron foil. This detector is calibrated on an absolute scale before each experiment by counting etched tracks on an irradiated CR39 polymer plate. We present the performances and limits of this method and finally give typical fluence (dose) uncertainties for a standard irradiation in radiobiology.

  17. Particle beam therapy for cancer. A radiobiological perspective

    International Nuclear Information System (INIS)

    As for the particle beam therapy, there is to theoretical evidence by radiobiology. The particle beam therapy becomes high precision by development of the medicine engineering. We demonstrated the past contribution for the particle beam therapy and recent knowledge about radiobiological phenomenon such as (1) DNA damage and the repair, (2) cell killing effect, (3) metastasis, and (4) therapeutic gain. Finally, we discuss it about the radiobiological perspective for the particle beam therapy. (author)

  18. Experimental radiotherapy and clinical radiobiology. Vol. 20. Proceedings

    International Nuclear Information System (INIS)

    The proceedings include contributions on the following issues: laser driven proton accelerators on the way for radiotherapy, radiobiological evaluation of new radiations; molecular factors of radiation response; biological targeting; EGFR epidermal growth factor receptor/targeting - combined internal and external irradiation, radiobiology of normal tissues; dose-volume histograms for the radiotherapy: curves without radiobiological relevance or important information for the therapy planning; HPV (human papilloma virus) and radiation sensitivity of HNSCC (head and neck squamous cell carcinomas): evidence, radiobiological mechanism, clinical consequences and perspectives; mechanisms of action and intertumoral heterogeneity of response to EGFR inhibition in radiotherapy of solid tumors; evaluation of biomarkers for radiotherapy.

  19. Operation and Maintenance of the National Radiobiology Archives

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Anthony C. James; Stacey L. McCord

    2012-03-07

    The National Radiobiology Archives (NRA) are an archival program, started in 1989, to collect, organize and maintain data, laboratory notebooks, and animal tissue specimens from government (Department of Energy and its predecessor agencies) sponsored radiobiology life-span animal studies. These unique records, histopathology slides and paraffin embedded tissue blocks are maintained in a central facility and are available for further research study. The materials include electronic and paper records for each of more than 6,000 life-span-observations on dogs as well as details of major studies involving nearly 30,000 mice. Although these studies were performed over many years and at different laboratories with differing data management systems, the NRA has translated them into a standardized set of relational database tables. These can be distributed to interested individuals on written request. Specific Aims are: (1) To Maintain the Archive of Written Records from the Animal Experiments - The USTUR continued to maintain the NRA archives which consist of approximately 175 storage boxes containing laboratory notebooks, animal exposure records, animal pathologic records, and radiographs. These were stored in a 6,000 square foot leased facility in Richland, WA. Additionally, through a collaboration with Pacific Northwest National Laboratory's (PNNL) Low Dose Program, many of these records were scanned into digital files. These totaled 34 GB of data, which are saved in 2,407 separate PDF files that are organized by box number and animal identification number. (2) To Maintain the Archive of Animal Tissues at Washington State University - The USTUR continued to house the NRA dog tissue collection in the leased facility. The NRA tissue collection consisted of pathology slides and tissue blocks. Approximately 25% of the laboratory facility was dedicated to the storage of the NRA materials. (3) To Organize the Datasets of These Animals in the Context of Other Datasets so

  20. Plutonium concentration and 240Pu/239Pu atom ratio in biota collected from Amchitka Island, Alaska: recent measurements using ICP-SFMS

    International Nuclear Information System (INIS)

    Three underground nuclear tests, including the Unites States' largest, were conducted on Amchitka Island, Alaska. Monitoring of the radiological environment around the island is challenging because of its remote location. In 2008, the Department of Energy (DOE) Office of Legacy Management (LM) became responsible for the long term maintenance and surveillance of the Amchitka site. The first DOE LM environmental survey occurred in 2011 and is part of a cycle of activities that will occur every 5 years. The University of Alaska Fairbanks, a participant in the 2011 study, provided the lichen (Cladonia spp.), freshwater moss (Fontinalis neomexicanus), kelp (Eualaria fistulosa) and horse mussel (Modiolus modiolus) samples from Amchitka Island and Adak Island (a control site). These samples were analyzed for 239Pu and 240Pu concentration and 240Pu/239Pu atom ratio using inductively coupled plasma sector field mass spectrometry (ICP-SFMS). Plutonium concentrations and 240Pu/239Pu atom ratios were generally consistent with previous terrestrial and marine studies in the region. The 239+240Pu levels (mBq kg−1, dry weight) ranged from 3.79 to 57.1 for lichen, 167–700 for kelp, 27.9–148 for horse mussel, and 560–573 for moss. Lichen from Adak Island had higher Pu concentrations than Amchitka Island, the difference was likely the result of the higher precipitation at Adak compared to Amchitka. The 240Pu/239Pu atom ratios were significantly higher in marine samples compared to terrestrial and freshwater samples (t-test, p 240Pu/239Pu ratios in terrestrial samples are within the range of global fallout. • Elevated 240Pu/239Pu in marine samples was characteristic of North Pacific Ocean. • Potential sources of enriched Pu to the marine environment regionally are suggested. • Pu ratios cannot by themselves explain the enriched Pu in seawater around Amchitka

  1. Radiation monitoring considerations for radiobiology facilities

    International Nuclear Information System (INIS)

    Battelle, Pacific Northwest Laboratories, conducts a wide variety of radiobiology and radioecology research in a number of facilities on the Hanford Reservation. Review of radiation monitoring problems associated with storage, plant and animal experiments, waste handling and sterile facilities shows that careful monitoring, strict procedural controls and innovative techniques are required to minimize occupational exposure and control contamination. Although a wide variety of radioactivity levels are involved, much of the work is with extremely low level materials. Monitoring low level work is mundane and often impractical but cannot be ignored in today's ever tightening controls

  2. Radiobiological studies using gamma and x rays.

    Energy Technology Data Exchange (ETDEWEB)

    Potter, Charles Augustus; Longley, Susan W.; Scott, Bobby R. [Lovelace Respiratory Research Institute, Albuquerque, NM; Lin, Yong [Lovelace Respiratory Research Institute, Albuquerque, NM; Wilder, Julie [Lovelace Respiratory Research Institute, Albuquerque, NM; Hutt, Julie A. [Lovelace Respiratory Research Institute, Albuquerque, NM; Padilla, Mabel T. [Lovelace Respiratory Research Institute, Albuquerque, NM; Gott, Katherine M. [Lovelace Respiratory Research Institute, Albuquerque, NM

    2013-02-01

    There are approximately 500 self-shielded research irradiators used in various facilities throughout the U.S. These facilities use radioactive sources containing either 137Cs or 60Co for a variety of biological investigations. A report from the National Academy of Sciences[1] described the issues with security of particular radiation sources and the desire for their replacement. The participants in this effort prepared two peer-reviewed publications to document the results of radiobiological studies performed using photons from 320-kV x rays and 137Cs on cell cultures and mice. The effectiveness of X rays was shown to vary with cell type.

  3. Physics and radiobiology of nuclear medicine

    CERN Document Server

    Saha, Gopal B

    2010-01-01

    From a distinguished author comes this new edition for technologists, practitioners, residents, and students in radiology and nuclear medicine. Encompassing major topics in nuclear medicine from the basic physics of radioactive decay to instrumentation and radiobiology, it is an ideal review for Board and Registry examinations. The material is well organized and written with clarity. The book is supplemented with tables and illustrations throughout. It provides a quick reference book that is concise but comprehensive, and offers a complete discussion of topics for the nuclear medicine and radi

  4. New developments in fundamental and applied radiobiology

    International Nuclear Information System (INIS)

    The 23rd Annual Meeting of the European Society for Radiation Biology was held in Dublin, Eire, 23-26 September 1990. Papers presented were grouped into two themes:- (a) Promoting areas where new developments in cell and molecular biology are fundamentally altering concepts of radiation action (papers on radiation induced mutagenesis and transformations, dosimetry and risk, DNA damage and repair, low dose/low dose rate effects, and non-ionising radiation). (b) Areas where radiobiological information is directly important to the topic (papers on food irradiation, diagnostic imaging, environmental radiation, radiotherapy, and the oxygen effect). (UK)

  5. Generalized calculus in radiobiology: Physical implications

    CERN Document Server

    Sotolongo-Grau, O; Antoranz, J C; Sotolongo-Costa, Oscar

    2009-01-01

    Non-extensive statistical physics has allowed to generalize mathematical functions such as exponential and logarithms. The same framework is used to generalize sum and product so that the operations allow a more fluid way to work with mathematical expressions emerging from non-additive formulation of statistical physics. In this work we employ the generalization of the exponential, logarithm and product to obtain a formula for the survival fraction corresponding to the application of several radiation doses on a living tissue. Also we provide experimental recommendations to determine the universal characteristics of living tissues in interaction with radiation. These results have a potential application in radiobiology and radiation oncology.

  6. Long-Term Surveillance and Maintenance Plan for the U.S. Department of Energy Amchitka, Alaska, Site

    Energy Technology Data Exchange (ETDEWEB)

    None

    2008-09-01

    This Long-Term Surveillance and Maintenance Plan describes how the U.S. Department of Energy (DOE) intends to fulfill its mission to maintain protection of human health and the environment at the Amchitka, Alaska, Site1. Three underground nuclear tests were conducted on Amchitka Island. The U.S. Department of Defense, in conjunction with the U.S. Atomic Energy Commission (AEC), conducted the first nuclear test (Long Shot) to provide data that would improve the United States' capability of detecting underground nuclear explosions. The second nuclear test (Milrow) was a weapons-related test conducted by AEC as a means to study the feasibility of detonating a much larger device. The final nuclear test (Cannikin), the largest United States underground test, was a weapons-related test. Surface disturbances associated with these tests have been remediated. However, radioactivity remains deep below the surface, contained in and around the test cavities, for which no feasible remediation technology has been identified. In 2006, the groundwater model (Hassan et al. 2002) was updated using 2005 data collected by the Consortium for Risk Evaluation with Stakeholder Participation. Model simulation results indicate there is no breakthrough or seepage of radionuclides into the marine environment within 2,000 years. The Amchitka conceptual model is reasonable; the flow and transport simulation is based on the best available information and data. The simulation results are a quantitative prediction supported by the best available science and technology. This Long-Term Surveillance and Maintenance Plan is an additional step intended for the protection of human health and the environment. This plan may be modified from time to time in the future consistent with the mission to protect human health

  7. Long-Term Surveillance and Maintenance Plan for the U.S. Department of Energy Amchitka, Alaska, Site

    International Nuclear Information System (INIS)

    This Long-Term Surveillance and Maintenance Plan describes how the U.S. Department of Energy (DOE) intends to fulfill its mission to maintain protection of human health and the environment at the Amchitka, Alaska, Site1. Three underground nuclear tests were conducted on Amchitka Island. The U.S. Department of Defense, in conjunction with the U.S. Atomic Energy Commission (AEC), conducted the first nuclear test (Long Shot) to provide data that would improve the United States' capability of detecting underground nuclear explosions. The second nuclear test (Milrow) was a weapons-related test conducted by AEC as a means to study the feasibility of detonating a much larger device. The final nuclear test (Cannikin), the largest United States underground test, was a weapons-related test. Surface disturbances associated with these tests have been remediated. However, radioactivity remains deep below the surface, contained in and around the test cavities, for which no feasible remediation technology has been identified. In 2006, the groundwater model (Hassan et al. 2002) was updated using 2005 data collected by the Consortium for Risk Evaluation with Stakeholder Participation. Model simulation results indicate there is no breakthrough or seepage of radionuclides into the marine environment within 2,000 years. The Amchitka conceptual model is reasonable; the flow and transport simulation is based on the best available information and data. The simulation results are a quantitative prediction supported by the best available science and technology. This Long-Term Surveillance and Maintenance Plan is an additional step intended for the protection of human health and the environment. This plan may be modified from time to time in the future consistent with the mission to protect human health.

  8. Melanomas: radiobiology and role of radiation therapy

    International Nuclear Information System (INIS)

    Purpose/Objective: This course will review the radiobiology of malignant melanoma (MM) and the clinical use of radiation therapy for metastatic melanoma and selected primary sites. The course will emphasize the scientific principles underlying the clinical treatment of MM. Introduction: The incidence of malignant melanoma has one of the fastest growth rates in the world. In 1991, there were 32,000 cases and 7,000 deaths from MM in the United States. By the year 2000, one of every 90 Americans will develop MM. Wide local excision is the treatment of choice for Stage I-II cutaneous MM. Five-year survival rates depend on (a) sex: female-63%, male-40%; (b) tumor thickness: t 4 mm-25%; (c) location: extremity-60%, trunk-41%; and (d) regional lymph node status: negative-77%, positive-31%. Despite adequate surgery, 45-50% of all MM patients will develop metastatic disease. Radiobiology: Both the multi-target model: S = 1-(1-e-D/Do)n and the linear quadratic mode: -In(S) = alpha x D + beta x D2 predict a possible benefit for high dose per fraction (> 400 cGy) radiation therapy for some MM cell lines. The extrapolation number (n) varies from 1-100 for MM compared to other mammalian cells with n=2-4. The alpha/beta ratios for a variety of MM cell lines vary from 1 to 33. Other radiobiologic factors (repair of potentially lethal damage, hypoxia, reoxygenation, and repopulation) predict a wide variety of clinical responses to different time-dose prescriptions including high dose per fraction (> 400 cGy), low dose per fraction (200-300 cGy), or b.i.d. therapy. Based on a review of the radiobiology of MM, no single therapeutic strategy emerges which could be expected to be successful for all tumors. Time-Dose Prescriptions: A review of the retrospective and prospective clinical trials evaluating various time-dose prescriptions for MM reveals: (1) MM is a radiosensitive tumor over a wide range of diverse time-dose prescriptions; and (2) The high clinical response rates to a

  9. VI Congress on radiation research (radiobiology, radioecology, radiation safety). Abstracts. Volume 1 (sections I-VII)

    International Nuclear Information System (INIS)

    The collection contains abstracts at the VI Congress on radiation studies, a program that included various aspects of the action of ionizing and non-ionizing radiation on living organisms, problems of radioecology and radiation safety of human health and environment. Congress is confined to the 25th anniversary of the accident at the Chernobyl NPP. Several reports have summarized the 25-years studying the effects of the accident, articulated forecasts and the main directions of further research. The first volume contains the plenary reports, presentations on the sections of radiation biochemistry and molecular radiobiology, radiation genetics, radiation immunology and hematology, medical and biological aspects of radiation effect, mechanisms of low dose and low intensity radiation effects, long-term effects of radiation. Radiation protection and modification of radiation effects, radiobiology of tumors, problems of radiation therapy are under consideration

  10. Physics and radiobiology of nuclear medicine

    CERN Document Server

    Saha, Gopal B

    2013-01-01

    The Fourth Edition of Dr. Gopal B. Saha’s Physics and Radiobiology of Nuclear Medicine was prompted by the need to provide up-to-date information to keep pace with the perpetual growth and improvement in the instrumentation and techniques employed in nuclear medicine since the last edition published in 2006. Like previous editions, the book is intended for radiology and nuclear medicine residents to prepare for the American Board of Nuclear Medicine, American Board of Radiology, and American Board of Science in Nuclear Medicine examinations, all of which require a strong physics background. Additionally, the book will serve as a textbook on nuclear medicine physics for nuclear medicine technologists taking the Nuclear Medicine Technology Certification Board examination.

  11. Basics of radiobiology and nuclear medicine

    International Nuclear Information System (INIS)

    The authors successively reveal the topics of the biological impact of radiation (radiobiology) and the diagnostic and the therapeutic application of radiopharmaceuticals (nuclear medicine). Data on the influence of radiation on subcellular, cellular, tissue and organ level are given, on early and late radiation changes, as well. Indication for the application of the different radionuclide methods in the diagnosis of the diseases in the endocrinology, nephrology, cardiology, gastroenterology, haematology of lungs, bones, tumors are pointed out and the main trends of the growing therapeutical use of nuclear medicine are presented. The aim is to teach students the nuclear medicine methods in the complex investigation of the patients, his preliminary preparation and the biological impact of radiation and its risk. Self assessment test for students are proposed and a literature for further reading

  12. Radiobiological characteristic of tritium-labelled lysine

    International Nuclear Information System (INIS)

    Experiments on mice and rats injected with tritium-labeled lysine have revealed that one day after injection about 80% of the label was retained in organs and tissues as tissue-bound tritium. Retention curves for tritium in the body were decomposed into two exponentials. The biological half-lives of tritium-labeled lysine in various tissues exceed half-lives of other tritiated amino acids and of triated water. The average dose in different tissues following injection of tritiated lysine exceeds that from equal of tritium oxide (THO) by 1.5-8 times. Contribution of the tissue-bound tritium in dose is about 90%. radiobiological experiments showed strong genetic and citotoxic effects in male mice after injection of tritium-labeled lysine

  13. Harmonization of radiobiological assays: why and how?

    International Nuclear Information System (INIS)

    The International Atomic Energy Agency has made available a technical manual for cytogenetic biodosimetry assays (dicentric chromosome aberration (DCA) and cytokinesis-block micronucleus (CBMN) assays) used for radiation dose assessment in radiation accidents. The International Standardization Organization, which develops standards and guidelines, also provides an avenue for laboratory accreditation, has developed guidelines and recommendations for performing cytogenetic biodosimetry assays. Harmonization of DCA and CBMN assays, has improved their accuracy. Double-blinded inter-laboratory comparison studies involving several networks have further validated DCA and CBMN assays and improved the confidence in their potential use for radiation dose assessment in mass casualties. This kind of international harmonization is lacking for pre-clinical radiobiology assays. The widely used pre-clinical assays that are relatively important to set stage for clinical trials include clonogenic assays, flow-cytometry assays, apoptotic assays, and tumor regression and growth delay assays. However, significant inter-laboratory variations occur with respect to data among laboratories. This raises concerns on the reliability and reproducibility of preclinical data that drives further development and translation. Lack of reproducibility may stem from a variety of factors such as poor scientist training, less than optimal experimental design, inadequate description of methodology, and impulse to publish only the positive data etc. Availability of technical manuals, standard operating procedures, accreditation avenues for laboratories performing such assays, inter-laboratory comparisons, and use of standardized protocols are necessary to enhance reliability and reproducibility. Thus, it is important that radiobiological assays are harmonized for laboratory protocols to ensure successful translation of pre-clinical research on radiation effect modulators to help design clinic trials with

  14. Radiobiology with heavy charged particles: a historical review

    Energy Technology Data Exchange (ETDEWEB)

    Skarsgard, L.D. [Dept. of Medical Biophysics, B.C. Cancer Research Centre and TRIUMF, Vancouver (Canada)

    1997-09-01

    The presentation will attempt to briefly review some of radiobiological data on the effects of heavy charged particles and to discuss the influence of those studies on the clinical application which followed. (orig./MG)

  15. The impact of modeling nuclear fragmentation on delivered dose and radiobiology in ion therapy

    International Nuclear Information System (INIS)

    The importance of nuclear interactions for ion therapy arises from the influence of the particle spectrum on, first, radiobiology and therefore also on treatment planning, second, the accuracy of measuring dose and, third, the delivered dose distribution. This study tries to determine the qualitative as well as the quantitative influence of the modeling of inelastic nuclear interactions on ion therapy. Thereby, three key disciplines are investigated, namely dose delivery, dose assessment and radiobiology. In order to perform a quantitative analysis, a relative comparison between six different descriptions of nuclear interactions is carried out for carbon ions. The particle transport is simulated with the Monte Carlo code SHIELD-HIT10A while dose planning and radiobiology are covered by the analytic treatment planning program for particles TRiP, which determines the relative biological effectiveness (RBE) with the local effect model. The obtained results show that the physical dose distribution can in principle be significantly influenced by the modeling of fragmentation (about 10% for a 20% change in all inelastic nuclear cross sections for a target volume ranging from 15 to 25 cm). While the impact of nuclear fragmentation on stopping power ratios can be neglected, the fluence correction factor may be influenced by the applied nuclear models. In contrast to the results for the physical dose, the variation of the RBE is only small (about 1% for a 20% change in all inelastic nuclear cross sections) suggesting a relatively weak dependence of radiobiology on the detailed composition of the particle energy spectrum of the mixed radiation field. Also, no significant change (about 0.2 mm) of the lateral penumbra of the RBE-weighted dose is observed. (paper)

  16. Radiobiology of Radiosurgery for the Central Nervous System

    Directory of Open Access Journals (Sweden)

    Antonio Santacroce

    2013-01-01

    Full Text Available According to Leksell radiosurgery is defined as “the delivery of a single, high dose of irradiation to a small and critically located intracranial volume through the intact skull.” Before its birth in the early 60s and its introduction in clinical therapeutic protocols in late the 80s dose application in radiation therapy of the brain for benign and malignant lesions was based on the administration of cumulative dose into a variable number of fractions. The rationale of dose fractionation is to lessen the risk of injury of normal tissue surrounding the target volume. Radiobiological studies of cell culture lines of malignant tumors and clinical experience with patients treated with conventional fractionated radiotherapy helped establishing this radiobiological principle. Radiosurgery provides a single high dose of radiation which translates into a specific toxic radiobiological response. Radiobiological investigations to study the effect of high dose focused radiation on the central nervous system began in late the 50s. It is well known currently that radiobiological principles applied for dose fractionation are not reproducible when single high dose of ionizing radiation is delivered. A review of the literature about radiobiology of radiosurgery for the central nervous system is presented.

  17. In vitro irradiation system for radiobiological experiments

    International Nuclear Information System (INIS)

    Although two-dimensional (2-D) monolayer cell cultures provide important information on basic tumor biology and radiobiology, they are not representative of the complexity of three-dimensional (3-D) solid tumors. In particular, new models reproducing clinical conditions as closely as possible are needed for radiobiological studies to provide information that can be translated from bench to bedside. We developed a novel system for the irradiation, under sterile conditions, of 3-D tumor spheroids, the in vitro model considered as a bridge between the complex architectural organization of in vivo tumors and the very simple one of in vitro monolayer cell cultures. The system exploits the same equipment as that used for patient treatments, without the need for dedicated and highly expensive instruments. To mimic the passage of radiation beams through human tissues before they reach the target tumor mass, 96-multiwell plates containing the multicellular tumor spheroids (MCTS) are inserted into a custom-built phantom made of plexiglass, the material most similar to water, the main component of human tissue. The system was used to irradiate CAEP- and A549-derived MCTS, pre-treated or not with 20 μM cisplatin, with a dose of 20 Gy delivered in one session. We also tested the same treatment schemes on monolayer CAEP and A549 cells. Our preliminary results indicated a significant increment in radiotoxicity 20 days after the end of irradiation in the CAEP spheroids pre-treated with cisplatin compared to those treated with cisplatin or irradiation alone. Conversely, the effect of the radio- chemotherapy combination in A549-derived MCTS was similar to that induced by cisplatin or irradiation alone. Finally, the 20 Gy dose did not affect cell survival in monolayer CAEP and A549 cells, whereas cisplatin or cisplatin plus radiation caused 100% cell death, regardless of the type of cell line used. We set up a system for the irradiation, under sterile conditions, of tumor cells

  18. Biophysical and biomathematical adventures in radiobiology

    International Nuclear Information System (INIS)

    Highlights of my biophysical and biomathematical adventures in radiobiology is presented. Early adventures involved developing ''state-vector models'' for specific harmful effects (cell killing, life shortening) of exposure to radiation. More recent adventures led to developing ''hazard-function models'' for predicting biological effects (e.g., cell killing, mutations, tumor induction) of combined exposure to different toxicants. Hazard-function models were also developed for predicting harm to man from exposure to large radiation doses. Major conclusions derived from the modeling adventures are as follows: (1) synergistic effects of different genotoxic agents should not occur at low doses; (2) for exposure of the lung or bone marrow to large doses of photon radiation, low rates of exposure should be better tolerated than high rates; and (3) for some types of radiation (e.g., alpha particles and fission neutrons), moderate doses delivered at a low rate may be more harmful than the same dose given at a high rate. 53 refs., 7 figs

  19. Radiobiological foundation of thermal neutron capture treatment

    International Nuclear Information System (INIS)

    Five radiobiological problems in thermal neutron capture treatment were considered on the basis of experimental data. As a result of an experiment of irradiation using thermal neutron generated by an atomic pile of Kyoto University, RBE of thermal neutron on cultured B-16 melanoma cells was determined to 2.43. Cultured B-16 melanoma cells did not recovered from sublethal damage when fractionated irradiation of thermal neutron was performed. To know additive effects of 10B-compounds, an amount of 10B-boric acid equivalent to 5 μg/ml of 10B was administered to culture medium for melanoma cells before the irradiation. As a result, Do values when 10B-boric acid was administered before irradiation were 3.3 times as much as those when only thermal neutron was irradiated, and RBE of thermal neutron when 10B-boric acid was administered was 3.04 RBE of 10B(n, α)7Li reaction (3.43) was also calculated. It was pointed out that it was difficult to estimate absorbed dose precisely by 10B(n, α)7Li reaction. It was also necessary to know the movement from proliferation to differentiation of cells accurately when neutron capture treatment using differential plasma of cancer cells was performed. (Tsunoda, M.)

  20. Monte Carlo role in radiobiological modelling of radiotherapy outcomes

    Science.gov (United States)

    El Naqa, Issam; Pater, Piotr; Seuntjens, Jan

    2012-06-01

    Radiobiological models are essential components of modern radiotherapy. They are increasingly applied to optimize and evaluate the quality of different treatment planning modalities. They are frequently used in designing new radiotherapy clinical trials by estimating the expected therapeutic ratio of new protocols. In radiobiology, the therapeutic ratio is estimated from the expected gain in tumour control probability (TCP) to the risk of normal tissue complication probability (NTCP). However, estimates of TCP/NTCP are currently based on the deterministic and simplistic linear-quadratic formalism with limited prediction power when applied prospectively. Given the complex and stochastic nature of the physical, chemical and biological interactions associated with spatial and temporal radiation induced effects in living tissues, it is conjectured that methods based on Monte Carlo (MC) analysis may provide better estimates of TCP/NTCP for radiotherapy treatment planning and trial design. Indeed, over the past few decades, methods based on MC have demonstrated superior performance for accurate simulation of radiation transport, tumour growth and particle track structures; however, successful application of modelling radiobiological response and outcomes in radiotherapy is still hampered with several challenges. In this review, we provide an overview of some of the main techniques used in radiobiological modelling for radiotherapy, with focus on the MC role as a promising computational vehicle. We highlight the current challenges, issues and future potentials of the MC approach towards a comprehensive systems-based framework in radiobiological modelling for radiotherapy.

  1. Proceedings of the 4th Radiobiological conference with international participation 2008

    International Nuclear Information System (INIS)

    Scientific conference deals with problems in radiobiology, photobiology and radio-environmental sciences. The Conference included the following sessions: (i): Radiobiology; (ii) Biology. Proceedings contains thirty-two papers dealing with the scope of INIS

  2. DOE/CEC [Department of Energy/Commission of the European Communities] workshop on critical evaluation of radiobiological data to biophysical modeling

    International Nuclear Information System (INIS)

    The Department of Energy's Office of Health and Environmental Research and the Commission of the European Communities (CEC) Radiation Protection Program support the majority of Research in the Field of Radiobiological Modeling. This field of science develops models based on scientifically sound principles to predict biological response (at the cellular, molecular, and animal level) to exposure to low level ionizing radiation. Biophysical models are an important tool for estimating response of ionizing radiation at low doses and dose rates. Generally speaking, the biophysical models can be classified into two groups: (1) mechanistic models and (2) phenomenological models. Mechanistic models are based on some assumptions about the physical, chemical, or biological mechanisms of action in association with radiobiological data whereas the phenomenological models are based solely on available experimental data on radiobiological effects with less emphasis on mechanisms of action. There are a number of these models which are being developed. Since model builders rely on radiobiological data available in the literature either to develop mechanistic or phenomenological models, it is essential that a critical evaluation of existing radiobiological data be made and data that is generally considered good and most appropriate for biophysical modeling be identified. A Workshop jointly sponsored by the DOE and the CEC was held at Oak Ridge, Tennessee from June 23--25, 1988, to review the data available from physical and chemical, cellular and molecular and animal studies with ionizing radiation

  3. National Radiobiology Archives distributed access programmer's guide

    Energy Technology Data Exchange (ETDEWEB)

    Prather, J. C. [Linfield Coll., McMinnville, OR (United States); Smith, S. K.; Watson, C. R. [Pacific Northwest Lab., Richland, WA (United States)

    1991-12-01

    The National Radiobiology Archives is a comprehensive effort to gather, organize, and catalog original data, representative specimens, and supporting materials related to significant radiobiology studies. This provides researchers with information for analyses which compare or combine results of these and other studies and with materials for analysis by advanced molecular biology techniques. This Programmer's Guide document describes the database access software, NRADEMO, and the subset loading script NRADEMO/MAINT/MAINTAIN, which comprise the National Laboratory Archives Distributed Access Package. The guide is intended for use by an experienced database management specialist. It contains information about the physical and logical organization of the software and data files. It also contains printouts of all the scripts and associated batch processing files. It is part of a suite of documents published by the National Radiobiology Archives.

  4. Modern concepts for basic radiobiological factors characterizing tumor tissue radiosensitivity

    International Nuclear Information System (INIS)

    Traditionally radiotherapy is prescribed at doses consistent with the expected therapeutic response and tolerance of tumor and normal tissues without consideration to individual differences in radiosensitivity. However, the basic radiobiological knowledge and clinical experience along this line point to significant variations in the observed therapeutic results. It has been established that cells and tissues under experimental and clinical conditions manifest a wide spectrum of individual radiosensitivity. The aim of this survey is to outline the current concepts for the basic radiobiological factors influencing tumor radiosensitivity. A thorough discussion is done of the essence, mechanisms of action, methods of determination and measurement, and effect on the prognosis in patients with malignant diseases of a number of radiobiological factors, such as: tumor-cell proliferation, apoptosis, tumor hypoxia and neovascularization. Although the knowledge of the mechanisms of radiosensitivity is constantly expanding, its clinical implementation is still rather limited. The true role of radiosensitivity in predicting the therapeutic response should be more accurately defined. (authors)

  5. [Radiobiological aspects of diagnostic X-ray use in dentistry].

    Science.gov (United States)

    Hoogeveen, R C; van den Aardweg, G J M J

    2015-05-01

    Soon after the discovery of X-rays, it became clear that their use can cause detrimental effects. The field of radiobiology deals with these detrimental effects. In this article, the theoretical concepts of radiobiology relevant to diagnostic X-ray use are presented. The effects of radiation on living tissues, the relationship between dose and effect, and a translation of these effects into the dental application are discussed. X-rays cannot be considered to be harmless even when used at the relatively low doses as in dentistry. If applied with justification and optimization, the risk to the patient will, however, be small. PMID:26210221

  6. New radiobiological, radiation risk and radiation protection paradigms

    International Nuclear Information System (INIS)

    The long-standing conventional paradigm for radiobiology has formed a logical basis for the standard paradigm for radiation risk of cancer and heritable effects and, from these paradigms, has developed the internationally applied system for radiation protection, but with many simplifications, assumptions and generalizations. A variety of additional radiobiological phenomena that do not conform to the standard paradigm for radiobiology may have potential implications for radiation risk and radiation protection. It is suggested, however, that the current state of knowledge is still insufficient for these phenomena, individually or collectively, to be formulated systematically into a new paradigm for radiobiology. Additionally, there is at present lack of direct evidence of their relevance to risk for human health, despite attractive hypotheses as to how they might be involved. Finally, it remains to be shown how incorporation of such phenomena into the paradigm for radiation protection would provide sufficient added value to offset disruption to the present widely applied system. Further research should aim for better mechanistic understanding of processes such as radiation-induced genomic instability (for all radiation types) and bystander effects (particularly for low-fluence high-LET particles) and also priority should be given to confirmation, or negation, of the relevance of the processes to human health risks from radiation.

  7. In vivo tumor radiobiology of heavy charged particles

    International Nuclear Information System (INIS)

    The response of tumor cells systems to irradiation with carbon, neon and argon beams at various positions in the plateau and extended-peak regions of the Bragg ionization curve is being evaluated from experiments conducted both in vivo and in vitro. The radiobiological end points being studied include: tumor volume response, cellular survival after tumor irradiation in situ, and cell-kinetic parameters

  8. Radiobiological researches on Dianthus caryophyllus L. carnation chimeras

    International Nuclear Information System (INIS)

    This research thesis reports a radiobiological study of Dianthus periclinal chimeras performed by submitting plants and plant cuttings at different physiological stages to cobalt-60 gamma irradiation under different dose conditions and rates. The effects of these treatments are studied while growing the so-processed plants and by microscopic examination of sections of irradiated meristems

  9. Biometrical analysis in radiobiological works of N.V. Luchnik

    International Nuclear Information System (INIS)

    The contribution of the famous Russian geneticist and biophysics N.V. Luchnik into biometrical analysis of radiobiological data is discussed. His works on radiation mortality of mice (2) and the process of post-radiation repair of chromosome aberrations (10) are thoroughly observed. The conclusion of necessity to develop biometrical analysis as separate part of biometry is made

  10. The ATM gene and the radiobiology of ataxia-telangiectasia

    International Nuclear Information System (INIS)

    Ataxia-telangiectasia (A-T) is the classic human genetic disease involving severe ionizing radiation sensitivity and as such has been intensely studied by radiation biologists over the years. Unlike its counterpart for UV light sensitivity -xeroderma pigmentosum - A-T has no obvious DNA repair defect; and there has been much speculation as to the mechanism underlying the altered radioresponses associated with this disease. The gene defective in A-T (ATM) has recently been cloned, and its primary coding sequence determined. The primary sequence of the ATM protein suggests that it has some regulatory functions related to cellular radioresponse and maintenance of genomic stability, and shares these functions with a growing family of other proteins in various organisms. At this juncture it is appropriate to review our current knowledge about the radiobiology of A-T and reflect on the possible radiobiological mechanisms that are suggested by the ATM gene itself. This article will attempt briefly to review current knowledge about the radiobiology of A-T and to introduce new speculations about underlying radiobiological mechanisms that are suggested by the primary amino acid sequence of the predicted ATM gene product. (Author)

  11. National Radiobiology Archives Distributed Access user's manual

    Energy Technology Data Exchange (ETDEWEB)

    Watson, C.; Smith, S. (Pacific Northwest Lab., Richland, WA (United States)); Prather, J. (Linfield Coll., McMinnville, OR (United States))

    1991-11-01

    This User's Manual describes installation and use of the National Radiobiology Archives (NRA) Distributed Access package. The package consists of a distributed subset of information representative of the NRA databases and database access software which provide an introduction to the scope and style of the NRA Information Systems.

  12. Evidence for intermittent radiobiological hypoxia in experimental tumour systems

    International Nuclear Information System (INIS)

    This paper describes flow and static fluorescence cytometry techniques to visualize and quantitate acute radiobiological hypoxia resulting from transient fluctuation in tumour blood flow in experimental tumour systems. The application of these techniques in two murine tumour systems provides evidence that such hypoxia exists and reduces the effectiveness of single doses of radiation. Possible mechanisms for and implications of these findings are discussed. (author)

  13. Optimization in brachytherapy with the implementation of Radiobiology

    International Nuclear Information System (INIS)

    In the brachytherapy planning treatments with High dose rates (HDR), the optimization algorithms used are based in dosimetric considerations and/or geometric ones, ignoring the radiobiological response of the tissue treated. In this work we wish to show the implementation of radiobiological concepts in the optimization. Assuming that the subtiles differences that result in the dose distribution among the different optimization models which are not visible in an isodose plane, it is studied how is classically make it , the quality implant through natural histograms about dose volumes and the resulting parameters. Also is studied the necrosis probability which may be caused by the choice of some optimization model, allowing with this the choice of the best implant. (Author)

  14. Radiobiology Department. Report of Activities 1977-1980

    International Nuclear Information System (INIS)

    The different research activities carried out by the Radiobiology Department of the CNEA over the 4-year period 1977-1980 are summarized. These activities were devoted to the study of the effects of radiation on different biological systems, to the search for adequate experimental models, and to the development of techniques permiting a correct evaluation of the information obtained. Topics covered are genetics, microbiology, somatic effects of radiation, pathology and the operation of the animal's house. (M.E.L.)

  15. (RadioBiological Optimization of External-Beam Radiotherapy

    Directory of Open Access Journals (Sweden)

    Alan E. Nahum

    2012-01-01

    Full Text Available “Biological optimization” (BIOP means planning treatments using (radiobiological criteria and models, that is, tumour control probability and normal-tissue complication probability. Four different levels of BIOP are identified: Level I is “isotoxic” individualization of prescription dose at fixed fraction number. is varied to keep the NTCP of the organ at risk constant. Significant improvements in local control are expected for non-small-cell lung tumours. Level II involves the determination of an individualized isotoxic combination of and fractionation scheme. This approach is appropriate for “parallel” OARs (lung, parotids. Examples are given using our BioSuite software. Hypofractionated SABR for early-stage NSCLC is effectively Level-II BIOP. Level-III BIOP uses radiobiological functions as part of the inverse planning of IMRT, for example, maximizing TCP whilst not exceeding a given NTCP. This results in non-uniform target doses. The NTCP model parameters (reflecting tissue “architecture” drive the optimizer to emphasize different regions of the DVH, for example, penalising high doses for quasi-serial OARs such as rectum. Level-IV BIOP adds functional imaging information, for example, hypoxia or clonogen location, to Level III; examples are given of our prostate “dose painting” protocol, BioProp. The limitations of and uncertainties inherent in the radiobiological models are emphasized.

  16. In vitro irradiation station for broad beam radiobiological experiments

    Science.gov (United States)

    Wéra, A.-C.; Riquier, H.; Heuskin, A.-C.; Michiels, C.; Lucas, S.

    2011-12-01

    The study of the interaction of charged particles with living matter is of prime importance to the fields of radiotherapy, radioprotection and space radiobiology. Particle accelerators and their associated equipment are proven to be helpful tools in performing basic science in all these fields. Indeed, they can accelerate virtually any ions to a given energy and flux and let them interact with living matter either in vivo or in vitro. In this context, the University of Namur has developed a broad beam in vitro irradiation station for use in radiobiological experiments. Cells are handled in GLP conditions and can be irradiated at various fluxes with ions ranging from hydrogen to carbon. The station is mounted on a 2 MV tandem accelerator, and the energy range can be set up in the linear energy transfer (LET) ranges that are useful for radiobiological experiments. This paper describes the current status of the hardware that has been developed, and presents results related to its performance in term of dose-rate, energy range and beam uniformity for protons, alpha particles and carbon ions. The results of clonogenic assays of A549 lung adenocarcinoma cells irradiated with protons and alpha particles are also presented and compared with literature.

  17. In vitro irradiation station for broad beam radiobiological experiments

    Energy Technology Data Exchange (ETDEWEB)

    Wera, A.-C., E-mail: anne-catharine.wera@fundp.ac.be [NAmur Research Institute for LIfe Sciences (NARILIS), Research Centre for the Physics of Matter and Radiation (PMR), University of Namur-FUNDP (Belgium); Riquier, H., E-mail: helene.riquier@fundp.ac.be [NAmur Research Institute for LIfe Sciences (NARILIS), Unite de Recherche de Biologie Cellulaire (URBC), University of Namur-FUNDP, Rue de Bruxelles, 61, B-5000 Namur (Belgium); Heuskin, A.-C., E-mail: anne-catherine.heuskin@fundp.ac.be [NAmur Research Institute for LIfe Sciences (NARILIS), Research Centre for the Physics of Matter and Radiation (PMR), University of Namur-FUNDP (Belgium); Michiels, C., E-mail: carine.michiels@fundp.ac.be [NAmur Research Institute for LIfe Sciences (NARILIS), Unite de Recherche de Biologie Cellulaire (URBC), University of Namur-FUNDP, Rue de Bruxelles, 61, B-5000 Namur (Belgium); Lucas, S., E-mail: stephane.lucas@fundp.ac.be [NAmur Research Institute for LIfe Sciences (NARILIS), Research Centre for the Physics of Matter and Radiation (PMR), University of Namur-FUNDP (Belgium)

    2011-12-15

    The study of the interaction of charged particles with living matter is of prime importance to the fields of radiotherapy, radioprotection and space radiobiology. Particle accelerators and their associated equipment are proven to be helpful tools in performing basic science in all these fields. Indeed, they can accelerate virtually any ions to a given energy and flux and let them interact with living matter either in vivo or in vitro. In this context, the University of Namur has developed a broad beam in vitro irradiation station for use in radiobiological experiments. Cells are handled in GLP conditions and can be irradiated at various fluxes with ions ranging from hydrogen to carbon. The station is mounted on a 2 MV tandem accelerator, and the energy range can be set up in the linear energy transfer (LET) ranges that are useful for radiobiological experiments. This paper describes the current status of the hardware that has been developed, and presents results related to its performance in term of dose-rate, energy range and beam uniformity for protons, alpha particles and carbon ions. The results of clonogenic assays of A549 lung adenocarcinoma cells irradiated with protons and alpha particles are also presented and compared with literature.

  18. Experimental radiotherapy and clinical radiobiology. Vol. 20. Proceedings; Experimentelle Strahlentherapie und Klinische Strahlenbiologie. Bd. 20. Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Baumann, Michael; Dahm-Daphi, Jochen; Dikomey, Ekkehard; Petersen, Cordula; Rodemannn, Hans-Peter; Zips, Daniel (eds.)

    2011-07-01

    The proceedings include contributions on the following issues: laser driven proton accelerators on the way for radiotherapy, radiobiological evaluation of new radiations; molecular factors of radiation response; biological targeting; EGFR epidermal growth factor receptor/targeting - combined internal and external irradiation, radiobiology of normal tissues; dose-volume histograms for the radiotherapy: curves without radiobiological relevance or important information for the therapy planning; HPV (human papilloma virus) and radiation sensitivity of HNSCC (head and neck squamous cell carcinomas): evidence, radiobiological mechanism, clinical consequences and perspectives; mechanisms of action and intertumoral heterogeneity of response to EGFR inhibition in radiotherapy of solid tumors; evaluation of biomarkers for radiotherapy.

  19. Radiobiological modeling with MarCell software

    Energy Technology Data Exchange (ETDEWEB)

    Hasan, J.S.; Jones, T.D. [Oak Ridge National Lab., TN (United States). Health Sciences Research Div.

    1999-01-01

    A nonlinear system of differential equations that models the bone marrow cellular kinetics associated with radiation injury, molecular repair, and compensatory cell proliferation has been extensively documented. Recently, that model has been implemented as MarCell, a user-friendly MS-DOS computer program that allows users with little knowledge of the original model to evaluate complex radiation exposure scenarios. The software allows modeling with the following radiations: tritium beta, 100 kVp X, 250 kVp X, 22 MV X, {sup 60}Co, {sup 137}Cs, 2 MeV electrons, triga neutrons, D-T neutrons, and 3 blends of mixed-field fission radiations. The possible cell lineages are stem, stroma, and leukemia/lymphoma, and the available species include mouse, rat, dog, sheep, swine, burro, and man. An attractive mathematical feature is that any protracted protocol can be expressed as an equivalent prompt dose for either the source used or for a reference, such as 250 kVp X rays or {sup 60}Co. Output from MarCell includes: risk of 30-day mortality; risk of cancer and leukemia based either on cytopenia or compensatory cell proliferation; cell survival plots as a function of time or dose; and 4-week recovery kinetics following treatment. In this article, the program`s applicability and ease of use are demonstrated by evaluating a medical total body irradiation protocol and a nuclear fallout scenario.

  20. Assessment of radiobiological metrics applied to patient-specific QA process of VMAT prostate treatments.

    Science.gov (United States)

    Clemente-Gutiérrez, Francisco; Pérez-Vara, Consuelo; Clavo-Herranz, María H; López-Carrizosa, Concepción; Pérez-Regadera, José; Ibáñez-Villoslada, Carmen

    2016-01-01

    VMAT is a powerful technique to deliver hypofractionated prostate treatments. The lack of correlations between usual 2D pretreatment QA results and the clini-cal impact of possible mistakes has allowed the development of 3D verification systems. Dose determination on patient anatomy has provided clinical predictive capability to patient-specific QA process. Dose-volume metrics, as evaluation crite-ria, should be replaced or complemented by radiobiological indices. These metrics can be incorporated into individualized QA extracting the information for response parameters (gEUD, TCP, NTCP) from DVHs. The aim of this study is to assess the role of two 3D verification systems dealing with radiobiological metrics applied to a prostate VMAT QA program. Radiobiological calculations were performed for AAPM TG-166 test cases. Maximum differences were 9.3% for gEUD, -1.3% for TCP, and 5.3% for NTCP calculations. Gamma tests and DVH-based comparisons were carried out for both systems in order to assess their performance in 3D dose determination for prostate treatments (high-, intermediate-, and low-risk, as well as prostate bed patients). Mean gamma passing rates for all structures were bet-ter than 92.0% and 99.1% for both 2%/2 mm and 3%/3 mm criteria. Maximum discrepancies were (2.4% ± 0.8%) and (6.2% ± 1.3%) for targets and normal tis-sues, respectively. Values for gEUD, TCP, and NTCP were extracted from TPS and compared to the results obtained with the two systems. Three models were used for TCP calculations (Poisson, sigmoidal, and Niemierko) and two models for NTCP determinations (LKB and Niemierko). The maximum mean difference for gEUD calculations was (4.7% ± 1.3%); for TCP, the maximum discrepancy was (-2.4% ± 1.1%); and NTCP comparisons led to a maximum deviation of (1.5% ± 0.5%). The potential usefulness of biological metrics in patient-specific QA has been explored. Both systems have been successfully assessed as potential tools for evaluating the clinical

  1. Application of SSNTDs in radiobiological investigations aboard recoverable satellites.

    Science.gov (United States)

    Huang, R Q; Gu, R Q; Li, Q

    1997-01-01

    In recent years some Biostack experiments including a wide spectrum of biological objects have been devoted to study of the radiobiological effects on dry seeds aboard recoverable satellites. Some impressive phenomena have been observed. Clearly, the large amount of energy deposited by the highly ionizing heavy nuclei of cosmic rays is the principal reason for the induced aberrations of the chromosomes of wheat root tip cells. A methodical description of the experimental arrangement and procedure of handling and evaluation of given. The preliminary physical and biological results from the experimental "wheat seeds" are presented. PMID:11541794

  2. Experimental radiotherapy and clinical radiobiology. Vol. 22. Proceedings

    International Nuclear Information System (INIS)

    The proceedings of the 25th symposium on experimental radiotherapy and clinical radiobiology include papers on the following issues: radiotherapy individualization based on imaging; pre-clinic imaging and new experimental methods; methods and models, micromilieu and metabolism, combined therapy; secondary tumors following radiotherapy; radiogenic effects in normal tissue; resistance mechanism of tumors and normal tissue; personalized radio-oncology - which biological data are needed; pre-clinic and personalized radio-oncology; biomarkers - pre-clinic and translational; translational examinations for personalized radio-oncology.

  3. Toxicological and radiobiological characteristics of some S -derivatives of meprin

    International Nuclear Information System (INIS)

    Structural variants with radiobiological properties of alpha-mercaptopropinolylglycine (α-MPG, thiol, meprin) are searched with the aim of revealing preparations with increased radioprotective properties. Results of studying toxicologic and radioprotective properties of a number of synthesized compounds-thiosulphate (TSPG) isothiouranium (ITPG) diethyldithiocarbamate (DDTCPG) and thiophosphate (TPPG) α-MPG derivatives, are presented. The experiments on mice have shown that PSPG has low toxicity and satisfactory radioprotective activity when introduced 4 hours before irradiation. DDTCPG brings about a slight protective effect in the dose of 1300 mg/kg it does not produce radioprotective effect. Low toxicity and high radioprotective TPPG effect prove the necessity of its further study

  4. Experimental radiotherapy and clinical radiobiology. Vol. 18. Proceedings

    International Nuclear Information System (INIS)

    The proceedings on experimental radiotherapy and clinical radiobiology contain two review articles (prediction of normal tissue reactions after radiotherapy, ?H2AX foci as a marker for DNA double-strand breaks) and 34 contributions to the following topics: Hypoxia and molecular mechanisms of radiation resistance; biological imaging of the tumor micromilieu; DNA repair, genomic instability and carcerogenesis; molecular factors of radiation resistance; actual controversial discussion on possible irradiation caused metastasis risk enhancement; EGFR inhibition and irradiation; biology of experimental radiation/ normal tissue toxicity

  5. Radiobiological research for improving cancer therapy in India: rationale, problems and prospects

    International Nuclear Information System (INIS)

    Cancer is emerging as a very important health hazard in India. According to recent studies by the Indian Council of Medical Research, about 2.25 million patients are presently suffering from different types of cancer in India. Approximately one million new cases are diagnosed, and nearly 0.3 million deaths occur every year on account of this disease. About 2/3rd of the cancers are at an advanced stage at the time of diagnosis. However, the allocation of funds for healthcare in India to support the research efforts for developing more potent radio-chemotherapy protocols for cancer treatment is too little. Studies by the W.H.O. have estimated that less developed countries including India use less than 5% of world resources destined for cancer control. It follows from the above discussions that it is imperative to further encourage and diversify the radiobiological research in India. This can be achieved by creating radiobiological research facilities, mainly in all the cancer centers and post graduate medical institutions, and further expanding the upcoming laboratories in the universities such as Bikaner. Collaborative research programs between laboratories at different centers could facilitate systematic evaluation of various pharmacological agents and neutraceuticals for potential application for treatment of different cancers. Our studies on combination of radiation with temozolomide and certain adjuvants with selective effects on brain tumour cells will be very briefly discussed in this presentation. Finally the possible administrative set up and multi dimensional collaborations for cost effective utilization of existing resources to further augment radiation biology research will also be discussed

  6. A biomonitoring plan for assessing potential radionuclide exposure using Amchitka Island in the Aleutian chain of Alaska as a case study

    International Nuclear Information System (INIS)

    With the ending of the Cold War, the US and other nations were faced with a legacy of nuclear wastes. For some sites where hazardous nuclear wastes will remain in place, methods must be developed to protect human health and the environment. Biomonitoring is one method of assessing the status and trends of potential radionuclide exposure from nuclear waste sites, and of providing the public with early warning of any potential harmful exposure. Amchitka Island (51o N lat, 179o E long) was the site of three underground nuclear tests from 1965 to 1971. Following a substantive study of radionuclide levels in biota from the marine environment around Amchitka and a reference site, we developed a suite of bioindicators (with suggested isotopes) that can serve as a model for other sites contaminated with radionuclides. Although the species selection was site-specific, the methods can provide a framework for other sites. We selected bioindicators using five criteria: (1) occurrence at all three test shots (and reference site), (2) receptor groups (subsistence foods, commercial species, and food chain nodes), (3) species groups (plants, invertebrates, fish, and birds), (4) trophic levels, and (5) an accumulator of one or several radionuclides. Our major objective was to identify bioindicators that could serve for both human health and the ecosystem, and were abundant enough to collect adjacent to the three test sites and at the reference site. Site-specific information on both biota availability and isotope levels was essential in the final selection of bioindicators. Actinides bioaccumulated in algae and invertebrates, while radiocesium accumulated in higher trophic level birds and fish. Thus, unlike biomonitoring schemes developed for heavy metals or other contaminants, top-level predators are not sufficient to evaluate potential radionuclide exposure at Amchitka. The process described in this paper resulted in the selection of Fucus, Alaria fistulosa, blue mussel (Mytilus

  7. Development of radiobiology for oncology-a personal view

    International Nuclear Information System (INIS)

    When I came into radiotherapy in 1950, I was puzzled that some patients were treated to 3000 rads (cGy) in 3 weeks but others received 4000 in 5 or 6000 in 6 weeks. When I asked why, there were no convincing answers given, except 'this is what we usually do'. It wasn't until I went to a course on 'Radiobiology for Radiotherapy' in Cambridge that I learnt about the basic theories of Douglas Lea and the very considerable history of research into radiobiology and clinical radiotherapy. And there were still some questions outstanding, such as the relative importance of intracellular repair between 'daily' fractions, whether a 2 day gap each week was a good or a bad idea, and the role of proliferation, if any, during irradiation. I thought that a few simple animal experiments might help to give answers! That led me to a continuing interest in these questions and answers, which has taken me more than 50 years to pursue. This is the very personal story of what I saw happening in the subject, decade by decade. I was happy to experience all this together with scientists in many other countries, and our own, along the way. (review)

  8. A radiobiological review on melatonin. A novel radioprotector

    International Nuclear Information System (INIS)

    Complete text of publication follows. For the sake of improvement in radiation therapy, radiobiology plays a crucial role through explaining observed phenomena, and suggesting improvements to existing therapies. Due to the damaging effects of ionizing radiation, radiobiologists have long been interested in identifying novel, nontoxic, effective, and convenient compounds to protect humans against radiation induced normal tissue injuries. Melatonin (N-acetyl-5-methoxytryptamine), the chief secretory product of the pineal gland in the brain, has been documented to ameliorate the oxidative injuries due to ionizing radiation. This article reviews different features that make melatonin a potentially useful radioprotector. Moreover, based on radiobiological models we hypothesize that melatonin may postpone the saturation of repair enzymes which leads to repairing more induced damage by repair system and more importantly allows the use of higher doses of radiation during radiotherapy to get a better therapeutic ratio. The implications of the accumulated observations suggest by virtue of melatonin's radioprotective and anticancer effects; it is time to use it as a radioprotector both for radiation workers and patients suffering from cancer either alone for cancer inhibition or in combination with traditional radiotherapy for getting a favorable efficacy/toxicity ratio during the treatment. Although compelling evidence suggests that melatonin may be effective for a variety of disorders, the optimum dose of melatonin for human radioprotection is yet to be determined by further research. We propose that, in the future melatonin improve therapeutic ratio in radiation oncology.

  9. An irradiation facility with a vertical beam for radiobiological studies

    CERN Document Server

    Besserer, J; Dellert, M; Gahn, C; Moosburger, M; Pemler, P; Quicken, P; Distel, L; Schuessler, H

    1999-01-01

    A vertical beam facility for radiobiological experiments was designed and constructed at the Munich Tandem-Accelerator Laboratory. The main part of the facility is a 90 deg. dipole magnet bending the beam of protons or heavy particles into a vertical upward direction, which is advantageous for wet-cell irradiation. After collimation the beam is spread out passively by thin scattering foils and dynamically by magnetic coils. A homogeneity of the radiation field better than +-5% has been achieved over the diameter of the exit window of 60 mm. The dose rate can be widely adjusted from single particles to more than 10 sup 1 sup 0 particles (i.e. hundreds of Grays) per second. The dose measurement is based on single-particle counting and on standard dosimeters. The detector system for dosimetry and irradiation control is described. In a first radiobiological experiment the cell survival of chinese hamster cells was measured after irradiation with 22.7 MeV protons and compared with the X-ray result.

  10. Hypofractionation in prostate cancer: radiobiological basis and clinical appliance.

    Science.gov (United States)

    Mangoni, M; Desideri, I; Detti, B; Bonomo, P; Greto, D; Paiar, F; Simontacchi, G; Meattini, I; Scoccianti, S; Masoni, T; Ciabatti, C; Turkaj, A; Serni, S; Minervini, A; Gacci, M; Carini, M; Livi, L

    2014-01-01

    External beam radiation therapy with conventional fractionation to a total dose of 76-80 Gy represents the most adopted treatment modality for prostate cancer. Dose escalation in this setting has been demonstrated to improve biochemical control with acceptable toxicity using contemporary radiotherapy techniques. Hypofractionated radiotherapy and stereotactic body radiation therapy have gained an increasing interest in recent years and they have the potential to become the standard of care even if long-term data about their efficacy and safety are not well established. Strong radiobiological basis supports the use of high dose for fraction in prostate cancer, due to the demonstrated exceptionally low values of α / β . Clinical experiences with hypofractionated and stereotactic radiotherapy (with an adequate biologically equivalent dose) demonstrated good tolerance, a PSA control comparable to conventional fractionation, and the advantage of shorter time period of treatment. This paper reviews the radiobiological findings that have led to the increasing use of hypofractionation in the management of prostate cancer and briefly analyzes the clinical experience in this setting. PMID:24999475

  11. Hypofractionation in Prostate Cancer: Radiobiological Basis and Clinical Appliance

    Directory of Open Access Journals (Sweden)

    M. Mangoni

    2014-01-01

    Full Text Available External beam radiation therapy with conventional fractionation to a total dose of 76–80 Gy represents the most adopted treatment modality for prostate cancer. Dose escalation in this setting has been demonstrated to improve biochemical control with acceptable toxicity using contemporary radiotherapy techniques. Hypofractionated radiotherapy and stereotactic body radiation therapy have gained an increasing interest in recent years and they have the potential to become the standard of care even if long-term data about their efficacy and safety are not well established. Strong radiobiological basis supports the use of high dose for fraction in prostate cancer, due to the demonstrated exceptionally low values of α/β. Clinical experiences with hypofractionated and stereotactic radiotherapy (with an adequate biologically equivalent dose demonstrated good tolerance, a PSA control comparable to conventional fractionation, and the advantage of shorter time period of treatment. This paper reviews the radiobiological findings that have led to the increasing use of hypofractionation in the management of prostate cancer and briefly analyzes the clinical experience in this setting.

  12. Some applications of radiation chemistry to biochemistry and radiobiology

    International Nuclear Information System (INIS)

    In this chapter illustrate the use of radiation chemistry as a tool in investigating biologically important radical reactions, and also outline some studies of models for radiobiological damage. Because aqueous solutions usually offer the most important matrix, an appreciation of the main features of water radiolysis will be essential. Most of the illustrations involve pulse radiolysis, and some familiarity with chemical kinetics is assumed. In addition to these and other chapters in this book, readers find the proceedings of a recent NATO Advanced Study Institute most useful. The authors shall not try to review here all the applications of radiation chemistry to biochemistry and biology, but they will illustrate, using selected examples, the main principles and practical advantages and problems. Another recent volume covers the main contributions of flash photolysis and pulse radiolysis to the chemistry of biology and medicine, complementing earlier reviews. Papers from symposia on radical processes in radiobiology and carcinogenesis, and on super-oxide dismutases, and proceedings of recent international congresses of radiation research, together with the other publications referred to above will enable the reader to gain a comprehensive overview of the role of radicals in biological processes and the contributions of radiation chemistry

  13. Influence of oxygen on the chemical stage of radiobiological mechanism

    Science.gov (United States)

    Barilla, Jiří; Lokajíček, Miloš V.; Pisaková, Hana; Simr, Pavel

    2016-07-01

    The simulation of the chemical stage of radiobiological mechanism may be very helpful in studying the radiobiological effect of ionizing radiation when the water radical clusters formed by the densely ionizing ends of primary or secondary charged particle may form DSBs damaging DNA molecules in living cells. It is possible to study not only the efficiency of individual radicals but also the influence of other species or radiomodifiers (mainly oxygen) being present in water medium during irradiation. The mathematical model based on Continuous Petri nets (proposed by us recently) will be described. It makes it possible to analyze two main processes running at the same time: chemical radical reactions and the diffusion of radical clusters formed during energy transfer. One may study the time change of radical concentrations due to the chemical reactions running during diffusion process. Some orientation results concerning the efficiency of individual radicals in DSB formation (in the case of Co60 radiation) will be presented; the influence of oxygen present in water medium during irradiation will be shown, too.

  14. Characterization and performances of DOSION, a dosimetry equipment dedicated to radiobiology experiments taking place at GANIL

    CERN Document Server

    Boissonnat, G; Balanzat, E; Boumard, F; Carniol, B; Colin, J; Cussol, D; Etasse, D; Fontbonne, C; Frelin, A -M; Hommet, J; Peronnel, J; Salvador, S

    2016-01-01

    Currently, radiobiology experiments using heavy ions at GANIL(Grand Acc\\'el\\'erateur National d'Ions Lourds) are conducted under the supervision of the CIMAP (Center for research on Ions, MAterials and Photonics). In this context, a new beam monitoring equipment named DOSION has been developed. It allows to perform measurements of accurate fluence and dose maps in near real time for each biological sample irradiated. In this paper, we present the detection system, its design, performances, calibration protocol and measurements performed during radiobiology experiments. This setup is currently available for any radiobiology experiments if one wishes to correlate one's own sample analysis to state of the art dosimetric references.

  15. Studies in the radiobiology of osteoradionecrosis and their clinical significance

    Energy Technology Data Exchange (ETDEWEB)

    Marx, R.E.; Johnson, R.P.

    1987-10-01

    The radiobiology of osteoradionecrosis is a complex of cellular death and cellular functional impairments from radiation energy transfers. Four studies of irradiated patients and a data base from 536 patients with osteoradionecrosis revealed separate pathophysiologic conditions for osteoradionecrosis induced by early trauma, osteoradionecrosis induced by late trauma, and spontaneous osteoradionecrosis. A large body of data suggested useful clinical guidelines for the management of irradiated patients. The guidelines, in part, include a recommendation for deferring radiation treatment for 21 days after tissue wounding, if possible; a relative contraindication to wounding tissue during a radiation course; a recommendation for the use of hyperbaric oxygen before wounding; and a strong recommendation to provide comprehensive dental care to the irradiated patient.

  16. Philosophy of veterinary radiobiology twenty years after the Chernobyl disaster

    International Nuclear Information System (INIS)

    The basic objective is to provide safe foodstuffs. This approach has connection with the food chain protection including the diagnostics and the acute radiation disease therapy at the farm animals. The extra significance is given to the research of technologies which can reduce the activity of the contaminated foodstuffs. In the field of the ionizing radiation effect research in live organisms attention should be devoted to the new alternative bio-tests. The low-dose effect or the interaction with other negative physical and chemical aspects of the environment is mainly considered. In cooperation with human medicine, it is necessary to develop radiotherapy and to study the effects of therapy and radiotherapy. From the standpoint of perspective technologies, it is advisable to focus on irradiation of the foodstuffs in veterinary radiobiology. (authors)

  17. Dictionary of radiation protection, radiobiology and nuclear medicine

    International Nuclear Information System (INIS)

    Radiation protection, including aspects of radiobiology, nuclear medicine, and nuclear legislation, has an important role within nuclear research and the use of radioactive materials. Radiation protection comprises all measures and efforts to prevent the unwanted distribution and negative influence of ionizing radiation, especially where the human organism and the living environment are involved. The increasing role of radiation protection is reflected by the foundation of institutes in all industrial countries to control such radiant energy and prevent radiation damage. Nowadays ionizing radiation is employed on a large scale for basic investigations in biochemistry, molecular biology and genetics, in soil tests, fertilization problems and pest control in agriculture, as well as for medicinal diagnoses and therapy. This dictionary is a thematic enlargement of the four-language 'Dictionary of Nuclear Engineering', compiled by the same author. It comprises about 12,000 terms in each language. (orig.)

  18. Method for validating radiobiological samples using a linear accelerator

    International Nuclear Information System (INIS)

    There is an immediate need for rapid triage of the population in case of a large scale exposure to ionizing radiation. Knowing the dose absorbed by the body will allow clinicians to administer medical treatment for the best chance of recovery for the victim. In addition, today's radiotherapy treatment could benefit from additional information regarding the patient's sensitivity to radiation before starting the treatment. As of today, there is no system in place to respond to this demand. This paper will describe specific procedures to mimic the effects of human exposure to ionizing radiation creating the tools for optimization of administered radiation dosimetry for radiotherapy and/or to estimate the doses of radiation received accidentally during a radiation event that could pose a danger to the public. In order to obtain irradiated biological samples to study ionizing radiation absorbed by the body, we performed ex-vivo irradiation of human blood samples using the linear accelerator (LINAC). The LINAC was implemented and calibrated for irradiating human whole blood samples. To test the calibration, a 2 Gy test run was successfully performed on a tube filled with water with an accuracy of 3% in dose distribution. To validate our technique the blood samples were ex-vivo irradiated and the results were analyzed using a gene expression assay to follow the effect of the ionizing irradiation by characterizing dose responsive biomarkers from radiobiological assays. The response of 5 genes was monitored resulting in expression increase with the dose of radiation received. The blood samples treated with the LINAC can provide effective irradiated blood samples suitable for molecular profiling to validate radiobiological measurements via the gene-expression based biodosimetry tools. (orig.)

  19. A statistical method for descriminating between alternative radiobiological models

    International Nuclear Information System (INIS)

    Radiobiological models assist understanding of the development of radiation damage, and may provide a basis for extrapolating dose-effect curves from high to low dose regions. Many models have been proposed such as multitarget and its modifications, enzymatic models, and those with a quadratic dose response relationship (i.e. αD + βD2 forms). It is difficult to distinguish between these because the statistical techniques used are almost always limited, in that one method can rarely be applied to the whole range of models. A general statistical procedure for parameter estimation (Maximum Liklihood Method) has been found applicable to a wide range of radiobiological models. The curve parameters are estimated using a computerised search that continues until the most likely set of values to fit the data is obtained. When the search is complete two procedures are carried out. First a goodness of fit test is applied which examines the applicability of an individual model to the data. Secondly an index is derived which provides an indication of the adequacy of any model compared with alternative models. Thus the models may be ranked according to how well they fit the data. For example, with one set of data, multitarget types were found to be more suitable than quadratic types (αD + βD2). This method should be of assitance is evaluating various models. It may also be profitably applied to selection of the most appropriate model to use, when it is necessary to extrapolate from high to low doses

  20. Refined testicular dosimetry and radiobiology in radionuclide therapy

    International Nuclear Information System (INIS)

    The full text of the publication follows. The testes are one of the most radiosensitive organs. They constitute an important critical target tissue both for external and internal exposure during diagnostic or therapeutic use of radionuclides. The testis consists of an egg-shaped tissue containing a large number of lobules. These are occupied by one to four seminiferous tubules, where the spermatogenesis takes place, i.e. the complex process where germ cells proliferate and transform into spermatozoa. The testicular cells have different sensitivity to radiation with the highest sensitivity of the undifferentiated spermatogonia close of the basal cell layer, and lowest sensitivity of the more mature sperm cells migrating towards the lumen. Exposure of the testis may occur due to radiopharmaceutical administration in patients either for therapy or diagnostic purposes, which may result in considerable high absorbed dose to the testis and may harm the testicular germ cells. In general the mean absorbed dose to the whole testis is estimated, which has been reported for different radionuclides and radiopharmaceuticals in the literature. However, due to the difference in radiosensitivity of the germ cells the absorbed doses to each type of cells in the seminiferous epithelium is of importance for a radiobiological interpretation. Testicular dosimetry on the cellular level is a complex matter and has not yet been addressed. The aim of this project was to design a small-scale anatomy model for calculation of S-factors (Gy MBq-1) for different source-target combinations, i.e. the interstitial tissue and different germ cells of the seminiferous epithelium. Based on this small-scale anatomy model it should be possible to estimate radiobiological effects based on radioactivity distribution determined by autoradiography, calculated differentiated absorbed doses, and known radiosensitivity of the different germ cells. The novel small-scale anatomy model will be presented and its

  1. The radiobiology/radiation protection interface in healthcare

    International Nuclear Information System (INIS)

    The current knowledge of radiation effects is reviewed and implications for its application in healthcare considered. The 21st L H Gray conference gathered leading experts in radiobiology, radiation epidemiology, radiation effect modelling, and the application of radiation in medicine to provide an overview of the subject. The latest radiobiology research in non-targeted effects such as genomic instability and the bystander effect challenge the old models, but the implications for health effects on humans are uncertain. Adaptive responses to external stresses, of which radiation is one, have been demonstrated in cells and animal models, but it is not known how these might modify human dose-effect relationships. Epidemiological evidence from the Japanese A-bomb survivors provides strong evidence that there is a linear relationship between the excess risk of cancer and organ dose that extends from about 50 mSv up to 2.5 Sv, and results from pooled data for multiple epidemiological studies indicate that risks extend down to doses of 20 mSv. Thus linear extrapolation of the A-bomb dose-effect data provides an appropriate basis for radiological protection standards at the present time. Risks from higher dose diagnostic procedures fall within the range in which health effects can be demonstrated. There is therefore reason for concern about the rise in the number of computed tomography (CT) scans performed in many countries, and in particular the use of CT for screening of asymptomatic individuals. New radiotherapy techniques allow high dose radiation fields to be conformed more effectively to target volumes, and reduce doses to critical organs, but they tend to give a higher and more uniform dose to the whole body which may increase the risk of second cancer. It is important that radiation protection practitioners keep abreast of developments in understanding of radiation effects and advise the medical community about the implications of fundamental research when

  2. Strategies to improve the efficacy of radioimmunotherapy: Radiobiologic aspects

    International Nuclear Information System (INIS)

    The purpose of this study was to investigate methods of improving the therapeutic index (dose to tumor/dose to normal organs) and, hence, the efficacy of radioimmunotherapy (RIT). One method investigated was to increase the biologic response for a given radiation dose to tumor. To enhance the biologic efficacy of the dose, initial studies focused on first understanding the radiobiology of RIT irradiation and determining what role factors, such as radiation repair, repopulation, and redistribution, play in determining RIT response. In vitro studies using 4 colon carcinoma cell lines have compared the radiobiologic efficacy of low dose-rate irradiation delivered by Yttrium-90 (Y-90) with conventional high dose-rate external beam irradiation (XRT). Results suggested that one factor which determined a cell's sensitivity to Y-90 irradiation was its ability to repair radiation sublethal damage. In vivo studies demonstrated that those cell lines which were more sensitive to Y-90 irradiation in vitro were also more sensitive to RIT in vivo. For a more radioresistant line, WiDr, RIT was approximately two-fold less effective than an equivalent dose of single fraction XRT, while for a more radiosensitive line, LS174T, RIT was approximately as effective as an equivalent dose of single fraction XRT. Therefore, a tumor's response to RIT in vivo appeared to be, in part, dependent on the tumor cell's ability to repair radiation damage. Finally, studies investigated strategies at enhancing the biologic efficacy of RIT irradiation by combining RIT with chemotherapy agents that can potentially inhibit radiation repair. Agents, such as 5-fluorouracil, appeared to be synergistic with RIT irradiation n vitro and may therefore prove promising in improving the therapeutic index of RIT

  3. Knowledge evolution on effects of ionizing radiations on living being. New prospects of radiobiological researches

    International Nuclear Information System (INIS)

    The knowledge increase of all the steps going from the material radiation interaction to the risk evaluation, prevention and irradiation consequences treatment leads to new prospects in radiobiology research, such as the low doses effects. (A.B.)

  4. Recent trends in radiobiology of skin and repercussions for dose limitation and personal dosimetry

    International Nuclear Information System (INIS)

    Recent advances in the radiobiology of skin are reviewed with particular emphasis on those aspects relevant to the updating of radiological protection criteria for skin dose limitation which is currently being undertaken by the ICRP and NCRP. (author)

  5. Press breakfast, radiobiology stakes: an European context, Thursday 25 March 2004

    International Nuclear Information System (INIS)

    The radiobiology endeavours to know the ionizing radiations effects on living systems, particular at low doses exposures. The researches in this area contribute to the elaboration of international regulation on nuclear industry. The individual radiosensitivity is an other aspect of the research in radiobiology. These studies should allow the establishing of radiation protection standards founded on a direct approach and an individual estimation of the level of acceptable dose. (N.C.)

  6. Proceedings of scientific conference of young scientists 'Fundamental and applied problems of radiobiology and radioecology'

    International Nuclear Information System (INIS)

    This book contains modern views on mechanisms of biological effects of ionising radiation in low doses and peculiarities of radionuclide migration in different ecosystems which are based on experimental data in works of young scientists represented on research conference 'Fundamental and applied problems of radiobiology and radioecology'. Special attentions of this publication are investigations in fields of radiation genetics and biochemistry, medical an biological aspects of radiation exposure, plant radiobiology and radioecology

  7. Modeling Groundwater Flow and Transport of Radionuclides at Amchitka Island's Underground Nuclear Tests: Milrow, Long Shot, and Cannikin

    Energy Technology Data Exchange (ETDEWEB)

    Ahmed Hassan; Karl Pohlmann; Jenny Chapman

    2002-11-19

    Since 1963, all United States nuclear tests have been conducted underground. A consequence of this testing has been the deposition of large amounts of radioactive material in the subsurface, sometimes in direct contact with groundwater. The majority of this testing occurred on the Nevada Test Site (NTS), but a limited number of experiments were conducted in other locations. One of these locations, Amchitka Island, Alaska is the subject of this report. Three underground nuclear tests were conducted on Amchitka Island. Long Shot was an 80-kiloton-yield test conducted at a depth of 700 meters (m) on October 29, 1965 (DOE, 2000). Milrow had an announced yield of about 1,000 kilotons, and was detonated at a depth of 1,220 m on October 2, 1969. Cannikin had an announced yield less than 5,000 kilotons, and was conducted at a depth of 1,790 m on November 6, 1971. The purpose of this work is to provide a portion of the information needed to conduct a human-health risk assessment of the potential hazard posed by the three underground nuclear tests on Amchitka Island. Specifically, the focus of this work is the subsurface transport portion, including the release of radionuclides from the underground cavities and their movement through the groundwater system to the point where they seep out of the ocean floor and into the marine environment. This requires a conceptual model of groundwater flow on the island using geologic, hydrologic, and chemical information, a numerical model for groundwater flow, a conceptual model of contaminant release and transport properties from the nuclear test cavities, and a numerical model for contaminant transport. Needed for the risk assessment are estimates of the quantity of radionuclides (in terms of mass flux) from the underground tests on Amchitka that could discharge to the ocean, the time of possible discharge, and the location in terms of distance from shoreline. The radionuclide data presented here are all reported in terms of normalized

  8. Evaluation of radiobiological effects in 3 distinct biological models

    International Nuclear Information System (INIS)

    Full text of publication follows. The present work aims at sharing the process of development of advanced biological models to study radiobiological effects. Recognizing several known limitations and difficulties of the current monolayer cellular models, as well as the increasing difficulties to use advanced biological models, our group has been developing advanced biological alternative models, namely three-dimensional cell cultures and a less explored animal model (the Zebra fish - Danio rerio - which allows the access to inter-generational data, while characterized by a great genetic homology towards the humans). These 3 models (monolayer cellular model, three-dimensional cell cultures and zebra fish) were externally irradiated with 100 mGy, 500 mGy or 1 Gy. The consequences of that irradiation were studied using cellular and molecular tests. Our previous experimental studies with 100 mGy external gamma irradiation of HepG2 monolayer cells showed a slight increase in the proliferation rate 24 h, 48 h and 72 h post irradiation. These results also pointed into the presence of certain bystander effects 72 h post irradiation, constituting the starting point for the need of a more accurate analysis realized with this work. At this stage, we continue focused on the acute biological effects. Obtained results, namely MTT and clonogenic assays for evaluating cellular metabolic activity and proliferation in the in vitro models, as well as proteomics for the evaluation of in vivo effects will be presented, discussed and explained. Several hypotheses will be presented and defended based on the facts previously demonstrated. This work aims at sharing the actual state and the results already available from this medium-term project, building the proof of the added value on applying these advanced models, while demonstrating the strongest and weakest points from all of them (so allowing the comparison between them and to base the subsequent choice for research groups starting

  9. Development of a single ion micro-irradiation facility for experimental radiobiology at cell level

    International Nuclear Information System (INIS)

    A micro-irradiation device has been developed for radiobiology applications at the scale of the cell. This device is based on an upgrade of an existing micro-beam line that was already able to deliver a 1 to 3 MeV proton or alpha beam of low intensity and whose space resolution is lower than 1 micrometer in vacuum. The important part of this work has been the development of an irradiation stage designed to fit on the micro-probe and able to deliver ions in the air with an absolute accuracy of a few micrometers. A program has been set up to monitor the complete irradiation line in testing and in automatic irradiation operating phases. Simulation tools based on Monte-Carlo calculations have been validated through comparisons with experimental data particularly in the field of spatial resolution and of the number of ions delivered. The promising results show the possibility in a near future to use this tool to study the response of cells to very low irradiation doses down to the extreme limit of one ion per cell

  10. Fisheries Radiobiology and the Discharge of Radioactive Wastes

    International Nuclear Information System (INIS)

    In the United Kingdom authorizations to discharge radioactive wastes are granted by the Minister of Housing and Local Government, the Minister of Agriculture, Fisheries and Food, and by the Secretary of State for Scotland. The hazards arising from contamination of aquatic animals and plants concern the Department of Fisheries ; before authorizations to discharge liquid wastes have been given, the Department has made independent forecasts of permissible levels of discharge based on extensive studies carried out in its research vessels and radiobiological laboratory: for example, where fish have been affected this has meant studies of fish populations and fish migration: uptake of radioactivity by fish : public consumption of fish : commercial distribution of affected fish: L.D.50: effects of radiation on tissue, etc. In the course of such work there has been close consultation with the Atomic Energy Authority, and agreement with the Atomic Energy Authority about the safety factor to be incorporated during the first two years of discharge. During these two years, monitoring data collected by the Atomic Energy Authority and the Ministry of Agriculture, Fisheries and Food enable checks and revisions of the original estimates to be made, and at the end of that time formal authorizations, based on operating experience, are issued. (author)

  11. Why do we need a new paradigm in radiobiology?

    International Nuclear Information System (INIS)

    Over the past 20 or so years experimental evidence, which questions the fundamentals of some 50 years standing, of both biology and radiobiology has accrued. In order to accommodate this new evidence within a framework that encompasses existing knowledge, attention has to be paid to the organisational or epigenetic, features of the cell. In recent years the high dimensional dynamic attractor has emerged as a potential organisational or regulatory agent that represents phenotype. It is argued here that its limited robustness provides a modus operandi to account for stress induced genomic instability. When radiation deposition events act to overcome the robustness of a normal or 'home' attractor in the cell of an established species and cause a transition to a variant attractor or phenotype, the consequences are unrelated to any specific molecular damage to the genomic DNA. Rather they correspond to the loss of evolutionarily acquired stability (genotypic replicative integrity) and robustness. Such processes are termed type B events and give rise to a separate category of effects and risk to those associated with the conventional effects of radiation, type A effects. How type B risks might be assessed is discussed.

  12. Radiobiological basis of radiation protection and ICRP 2007 general recommendations

    International Nuclear Information System (INIS)

    The ICRP 2007 General Recommendations are based on the detailed review of the new information on the biological effects and risk evaluation done during the last decade. Most of this information reinforces the validity of earlier findings. Since the publication of ICRP 60 general recommendations in 1991(ICRP 1991b), sufficient new information on the health effects of ionizing radiations has accrued based on radiobiological and epidemiological studies (UNSCEAR 2000, ICRP Publication 99). There is an improvement in understanding the mechanistic aspects of the induction of radiation damage at cellular level. Biophysical studies based on Monte Carlo track structure codes have provided information on the nature of critical damage to DNA leading to the radiation effects at cellular level. Experimental work with model animal systems has provided information on the role of post irradiation repair processes and the genes influencing the process of radiation carcinogenesis. Longer follow up of A-Bomb survivors of Hiroshima and Nagasaki now provides a more reliable risk estimate based on the cancer incidence data and also a better model for the transfer of risk among different populations with varying frequency of background incidence. At present it is clear that the breast cancer contributes substantially to the radiation risk and provides quantitative risk estimates for brain and salivary glands. In the light of the new information, Tissue Weighting factors (WT) have been revised

  13. Optimisation of exposure conditions for in vitro radiobiology experiments

    International Nuclear Information System (INIS)

    Despite the long history of using cell cultures in vitro for radiobiological studies, there is to date no study specifically addressing the dosimetric implications of flask selection and exposure environment in clonogenic assays. The consequent variability in dosimetry between laboratories impedes the comparison of results. In this study we compare the dose to cells adherent to the base of three types of commonly used culture flasks or plates. The cells are exposed to a 6MV clinical photon beam using either an open or a half blocked field. The depth of medium in each flask is varied with the medium surrounding the flask either water or air. The results show that the dose to the cells is more affected by the scattering conditions surrounding the flasks than by the level of filling within the flask. It is recommended that water or a water equivalent phantom material is used to surround the flasks or plates to approximate full scatter conditions at the cell layer. However for modulated fields, surrounding the 24 well plates with water-equivalent material is inadequate because of the large volume of air surrounding individual wells. Our results stress the importance of measuring the dose for new experimental configurations.

  14. Radiobiological problems connected to exposure from cosmic radiation

    International Nuclear Information System (INIS)

    Civil aircrews are exposed to cosmic radiation where the radiation contains a hadronic high energy component. Although radiobiological studies based on X-rays, γ-rays, fast neutrons and ions of varying LET values have shown that the repair of sublethal damage takes place in living cells at low doses, this ability decreases with increasing LET so that maximum radiation effects is observed at about 120 keV/μm. Experimental studies of the biological significance of the strong nuclear interaction reactions via very high energy neutrons, stopped negative pi mesons give signs of an increased effectiveness at very low doses from the present data. The few results obtained indicate that a collapse of the repair-mechanisms might take place for these fundamental reaction in nature. It is stressed that the contribution to the dose at present days civil air transport from cosmic radiation is small and taken care of by the existing recommendation for radiation protection., 8 refs., 7 figs., 5 tabs

  15. [Radiobiological analysis of cancerogenic risk values in radioepidemiological investigations].

    Science.gov (United States)

    Rozhdestvenskiĭ, L M

    2008-01-01

    The aim of the present article consisted in critical analysis of the epidemiological approach to radiocancerogenic risk estimation in region of low level radiation (LLR). The estimation is making by means of mathematician models that ignore a principal difference in biological action of LLR and high level radiation (HLR). The main formal characteristic of LLR action is the presence of a plateau in beginning of a dose-effect curve of radiogenic risk. It may be argued by the following positions: repeating the plateau-phenomenon on various radiobiological effects, in different tests and bioobjects, first; a paradoxical trend of reciprocal ERR/Sv increasing regarding dose decreasing in region of plateau, second, and third, the increasing of the curvature in dose-effect curve beginning. The presence of a plateau is associated with the presence of a real radiogenic risk threshold. Besides, the analysis of processes influencing significantly the dynamics of initial radiation injury of biologically important macromolecules showed the preference in region of LLR those, decreasing/eliminating genome damages. There is follows from mentioned above a necessity to evaluate radiogenic risks in LLR region separately from HLR region. PMID:18825986

  16. Radiobiological study by using laser-driven proton beams

    Science.gov (United States)

    Yogo, A.; Sato, K.; Nishikino, M.; Mori, M.; Teshima, T.; Numasaki, H.; Murakami, M.; Demizu, Y.; Akagi, S.; Nagayama, S.; Ogura, K.; Sagisaka, A.; Orimo, S.; Nishiuchi, M.; Pirozhkov, A. S.; Ikegami, M.; Tampo, M.; Sakaki, H.; Suzuki, M.; Daito, I.; Oishi, Y.; Sugiyama, H.; Kiriyama, H.; Okada, H.; Kanazawa, S.; Kondo, S.; Shimomura, T.; Nakai, Y.; Tanoue, M.; Sugiyama, H.; Sasao, H.; Wakai, D.; Kawachi, T.; Nishimura, H.; Bolton, P. R.; Daido, H.

    2009-07-01

    Particle acceleration driven by high-intensity laser systems is widely attracting interest as a potential alternative to conventional ion acceleration, including ion accelerator applications to tumor therapy. Recent works have shown that a high intensity laser pulse can produce single proton bunches of a high current and a short pulse duration. This unique feature of laser-ion acceleration can lead to progress in the development of novel ion sources. However, there has been no experimental study of the biological effects of laser-driven ion beams. We describe in this report the first demonstrated irradiation effect of laser-accelerated protons on human lung cancer cells. In-vitro A549 cells are irradiated with a proton dose of 20 Gy, resulting in a distinct formation of γ-H2AX foci as an indicator of DNA double-strand breaks. This is a pioneering result that points to future investigations of the radiobiological effects of laser-driven ion beams. The laser-driven ion beam is apotential excitation source for time-resolved determination of hydroxyl (OH) radical yield, which will explore relationship between the fundamental chemical reactions of radiation effects and consequent biological processes.

  17. Feasibility of BNCT radiobiological experiments at the HYTHOR facility

    Science.gov (United States)

    Esposito, J.; Ceballos, C.; Soncin, M.; Fabris, C.; Friso, E.; Moro, D.; Colautti, P.; Jori, G.; Rosi, G.; Nava, E.

    2008-06-01

    HYTHOR (HYbrid Thermal spectrum sHifter tapirO Reactor) is a new thermal-neutron irradiation facility, which was installed and became operative in mid 2005 at the TAPIRO (TAratura PIla Rapida potenza 0) fast reactor, in the Casaccia research centre (near Rome) of ENEA (Ente per le Nuove tecnologie Energia ed Ambiente). The facility has been designed for in vivo radiobiological studies. In HYTHOR irradiation cavity, 1-6 mice can be simultaneously irradiated to study skin melanoma treatments with the BNCT (boron neutron capture therapy). The therapeutic effects of HYTHOR radiation field on mouse melanoma has been studied as a preliminary investigation before studying the tumour local control due to boron neutron capture effect after boronated molecule injection. The method to properly irradiate small animals has been precisely defined. Results show that HYTHOR radiation field is by itself effective in reducing the tumour-growth rate. This finding has to be taken into account in studying the effectiveness of new 10B carriers. A method to properly measure the reduction of the tumour-growth rate is reported and discussed.

  18. Dosimetry for radiobiological experiments using energetic heavy ions

    International Nuclear Information System (INIS)

    The availability of the Bevalac facility of energetic heavy ions with range greater than the size of small mammals makes possible the determination of the biological effects of relatively well defined high LET, whole body irradiation. With the increasing application of high-energy heavy ions in radiobiology there is a corresponding need to develop reliable techniques of both relative and absolute absorbed dose measurement. This paper describes dosimetry studies by the Health Physics Department of the Lawrence Berkeley Laboratory with activation detectors, ionization chambers, nuclear emulsion, thermoluminescent dosimeters and X-ray film. The application of these techniques to an experiment designed to study the leukemogenic effect of the whole-body irradiation of mice by 250 MeV/amu carbon ions is briefly described. Values of absorbed dose in tissue, obtained during this experiment, with a nitrogen filled ionization chamber and 7LiF thermoluminescent dosimeters are compared and shown to be in good agreement. As a result of this work a value for the average energy to produce an ion pair (W) in nitrogen by 250 MeV/amu 6+C ions of 37 +- eV was determined. Values of the efficiency of 7LiF relative to 60Co γ-rays for ions with dE/dx in the range 110-260 MeV g-1 cm2 are reported

  19. Radiobiological research on carnation chimerae Dianthus Caryophyllus L

    International Nuclear Information System (INIS)

    A radiobiological study of periclinal carnation chimerae is carried out by subjecting whole plants and cuttings at different physiological stages to cobalt 60 gamma radiation under different dose and dose rate conditions. The effects of these treatments are observed during cultivation of the treated plants and by microscopic examination of irradiated meristem sections. The destruction of meristem cells in proportions varying with the irradiation conditions leads to structural changes in the chimerae; the more frequent change is the formation of genetically homogeneous stalks from different genotypes existing in the irradiated plant. Treatment by ionizing radiations is thus a practical means of detecting periclinical chimerae which, as in the case of carnations, are very common in plants grown by vegetative propagation. However since more than two independent meristem cell groups are usually present it is not possible by this method alone to define the distribution of the differentent genotypes in these groups; additional genetic studies or cell labelling such as chlorophyll or genoma mutations are then necessary

  20. Novel Radiobiological Gamma Index for Evaluation of 3-Dimensional Predicted Dose Distribution

    Energy Technology Data Exchange (ETDEWEB)

    Sumida, Iori, E-mail: sumida@radonc.med.osaka-u.ac.jp [Department of Radiation Oncology, Osaka University Graduate School of Medicine, Osaka (Japan); Yamaguchi, Hajime; Kizaki, Hisao; Aboshi, Keiko; Tsujii, Mari; Yoshikawa, Nobuhiko; Yamada, Yuji [Department of Radiation Oncology, NTT West Osaka Hospital, Osaka (Japan); Suzuki, Osamu; Seo, Yuji [Department of Radiation Oncology, Osaka University Graduate School of Medicine, Osaka (Japan); Isohashi, Fumiaki [Department of Radiation Oncology, NTT West Osaka Hospital, Osaka (Japan); Yoshioka, Yasuo [Department of Radiation Oncology, Osaka University Graduate School of Medicine, Osaka (Japan); Ogawa, Kazuhiko [Department of Radiation Oncology, NTT West Osaka Hospital, Osaka (Japan)

    2015-07-15

    Purpose: To propose a gamma index-based dose evaluation index that integrates the radiobiological parameters of tumor control (TCP) and normal tissue complication probabilities (NTCP). Methods and Materials: Fifteen prostate and head and neck (H&N) cancer patients received intensity modulated radiation therapy. Before treatment, patient-specific quality assurance was conducted via beam-by-beam analysis, and beam-specific dose error distributions were generated. The predicted 3-dimensional (3D) dose distribution was calculated by back-projection of relative dose error distribution per beam. A 3D gamma analysis of different organs (prostate: clinical [CTV] and planned target volumes [PTV], rectum, bladder, femoral heads; H&N: gross tumor volume [GTV], CTV, spinal cord, brain stem, both parotids) was performed using predicted and planned dose distributions under 2%/2 mm tolerance and physical gamma passing rate was calculated. TCP and NTCP values were calculated for voxels with physical gamma indices (PGI) >1. We propose a new radiobiological gamma index (RGI) to quantify the radiobiological effects of TCP and NTCP and calculate radiobiological gamma passing rates. Results: The mean RGI gamma passing rates for prostate cases were significantly different compared with those of PGI (P<.03–.001). The mean RGI gamma passing rates for H&N cases (except for GTV) were significantly different compared with those of PGI (P<.001). Differences in gamma passing rates between PGI and RGI were due to dose differences between the planned and predicted dose distributions. Radiobiological gamma distribution was visualized to identify areas where the dose was radiobiologically important. Conclusions: RGI was proposed to integrate radiobiological effects into PGI. This index would assist physicians and medical physicists not only in physical evaluations of treatment delivery accuracy, but also in clinical evaluations of predicted dose distribution.

  1. DOE life-span radiation effects studies in experimental animals at University of Utah Division of Radiobiology

    International Nuclear Information System (INIS)

    The Radiobiology Laboratory at the University of Utah compared the long-term biological effects of 226Ra and 239Pu in adult beagles. The program includes the investigation of other radionuclides. More recently, groups of juvenile and aged beagles were added to the study to investigate the influence of age at exposure. These studies involved single intravenous injection of radionuclides to small groups of beagles, in graded doses from levels at which no effects were expected up to levels where a 100% incidence of bone tumors was sometimes found. Some of the principal effects were bone tumors, fractures, and other skeletal alterations observed radiographically and histologically; emphasis was placed on the detection of precancerous changes, hematological changes, and changes related to aging. Emphasis was also placed on metabolic and autoradiographic studies necessary for good radiation dosimetry

  2. The significance of the choice of radiobiological (NTCP) models in treatment plan objective functions

    International Nuclear Information System (INIS)

    Full text: A Clinician's discrimination between radiation therapy treatment plans is traditionally a subjective process, based on experience and existing protocols. A more objective and quantitative approach to distinguish between treatment plans is to use radiobiological or dosimetric objective functions, based on radiobiological or dosimetric models. The efficacy of models is not well understood, nor is the correlation of the rank of plans resulting from the use of models compared to the traditional subjective approach. One such radiobiological model is the Normal Tissue Complication Probability (NTCP). Dosimetric models or indicators are more accepted in clinical practice. In this study, three radiobiological models, Lyman NTCP, critical volume NTCP and relative seriality NTCP, and three dosimetric models, Mean Lung Dose (MLD) and the Lung volumes irradiated at lOGy (V|0) and 20Gy (V20), were used to rank a series of treatment plans using, harm to normal (Lung) tissue as the objective criterion. None of the models considered in this study showed consistent correlation with the Radiation Oncologists plan ranking. If radiobiological or dosimetric models are to be used in objective functions for lung treatments, based on this study it is recommended that the Lyman NTCP model be used because it will provide most consistency with traditional clinician ranking.

  3. Radiobiological waste treatment-ashing treatment and immobilization with cement

    International Nuclear Information System (INIS)

    This report describes the results of the study on the treatment of radioactive biological waste in the China Institute for Radiation Protection (CIRP). The possibility of radiobiological waste treatment was investigated by using a RAF-3 type rapid ashing apparatus together with the immobilization of the resulted ash. This rapid ashing apparatus, developed by CIRP, is usually used for pretreatment of samples prior to chemical analysis and physical measurements. The results show that it can ash 3 kg of animal carcasses a batch, the ashing time is 5-7 h and the ash content is less than 4 wt%. The ashing temperature not exceeding 450 deg. C was used without any risk of high losses of radionuclides. The ash from the rapid ashing apparatus was demonstrated to be immobilized with ordinary silicate cement. The optimum cement/ash/water formulation of the cemented waste form was 35 ± 5 wt% cement, 29 ± 2 wt% water, and 36 ± 6 wt% ash. The performance of the waste form was in compliance with the technical requirements except for impact resistance. Mixing additives in immobilization formulations can improve the performance of the cemented ash waste form. The additives chosen were DH4A flow promoter as a cement additive and vermiculite or zeolite as a supplement. The recommended formulation, i.e. an improved formulation of the cemented ash waste form is that additives DH4A flow promoter and vermiculite (or zeolite) are added on the ground of optimum cement/ash/water formulation of the cemented waste form, the dosage of water, DH4A and vermiculite (or zeolite) is 70 wt%, 0.5 wt% and ≤ 5 wt% of the cement dosage, respectively. The cemented ash waste forms obtained meet all the requirements for disposal. (author). 12 refs, 7 figs, 13 tabs

  4. Heavy-ion tumor therapy: Physical and radiobiological benefits

    Science.gov (United States)

    Schardt, Dieter; Elsässer, Thilo; Schulz-Ertner, Daniela

    2010-01-01

    High-energy beams of charged nuclear particles (protons and heavier ions) offer significant advantages for the treatment of deep-seated local tumors in comparison to conventional megavolt photon therapy. Their physical depth-dose distribution in tissue is characterized by a small entrance dose and a distinct maximum (Bragg peak) near the end of range with a sharp fall-off at the distal edge. Taking full advantage of the well-defined range and the small lateral beam spread, modern scanning beam systems allow delivery of the dose with millimeter precision. In addition, projectiles heavier than protons such as carbon ions exhibit an enhanced biological effectiveness in the Bragg peak region caused by the dense ionization of individual particle tracks resulting in reduced cellular repair. This makes them particularly attractive for the treatment of radio-resistant tumors localized near organs at risk. While tumor therapy with protons is a well-established treatment modality with more than 60 000 patients treated worldwide, the application of heavy ions is so far restricted to a few facilities only. Nevertheless, results of clinical phase I-II trials provide evidence that carbon-ion radiotherapy might be beneficial in several tumor entities. This article reviews the progress in heavy-ion therapy, including physical and technical developments, radiobiological studies and models, as well as radiooncological studies. As a result of the promising clinical results obtained with carbon-ion beams in the past ten years at the Heavy Ion Medical Accelerator facility (Japan) and in a pilot project at GSI Darmstadt (Germany), the plans for new clinical centers for heavy-ion or combined proton and heavy-ion therapy have recently received a substantial boost.

  5. Radiobiological basis for setting neutron radiation safety standards

    International Nuclear Information System (INIS)

    Present neutron standards, adopted more than 20 yr ago from a weak radiobiological data base, have been in doubt for a number of years and are currently under challenge. Moreover, recent dosimetric re-evaluations indicate that Hiroshima neutron doses may have been much lower than previously thought, suggesting that direct data for neutron-induced cancer in humans may in fact not be available. These recent developments make it urgent to determine the extent to which neutron cancer risk in man can be estimated from data that are available. Two approaches are proposed here that are anchored in particularly robust epidemiological and experimental data and appear most likely to provide reliable estimates of neutron cancer risk in man. The first approach uses gamma-ray dose-response relationships for human carcinogenesis, available from Nagasaki (Hiroshima data are also considered), together with highly characterized neutron and gamma-ray data for human cytogenetics. When tested against relevant experimental data, this approach either adequately predicts or somewhat overestimates neutron tumorigenesis (and mutagenesis) in animals. The second approach also uses the Nagasaki gamma-ray cancer data, but together with neutron RBEs from animal tumorigenesis studies. Both approaches give similar results and provide a basis for setting neutron radiation safety standards. They appear to be an improvement over previous approaches, including those that rely on highly uncertain maximum neutron RBEs and unnecessary extrapolations of gamma-ray data to very low doses. Results suggest that, at the presently accepted neutron dose limit of 0.5 rad/yr, the cancer mortality risk to radiation workers is not very different from accidental mortality risks to workers in various nonradiation occupations

  6. SU-E-T-385: 4D Radiobiology

    Energy Technology Data Exchange (ETDEWEB)

    Fourkal, E; Hossain, M; Veltchev, I; Ma, C; Meyer, J; Horwitz, E [Fox Chase Cancer Center, Philadelphia, PA (United States); Nahum, A [Clatterbridge Centre for Oncology, Bebington (United Kingdom)

    2014-06-01

    Purpose: The linear-quadratic model is the most prevalent model for planning dose fractionation in radiation therapy in the low dose per fraction regimens. However for high-dose fractions, used in SRS/SBRT/HDR treatments the LQ model does not yield accurate predictions, due to neglecting the reduction in the number of sublethal lesions as a result of their conversion to lethal lesions with subsequent irradiation. Proper accounting for this reduction in the number of sublethally damaged lesions leads to the dependence of the survival fraction on the temporal structure of the dose. The main objective of this work is to show that the functional dependence of the dose rate on time in each voxel is an important additional factor that can significantly influence the TCP. Methods: Two SBRT lung plans have been used to calculate the TCPs for the same patient. One plan is a 3D conformal plan and the other is an IMRT plan. Both plans are normalized so that 99.5% of PTV volume receives the same prescription dose of 50 Gy in 5 fractions. The dose rate in each individual voxel is calculated as a function of treatment time and subsequently used in the calculation of TCP. Results: The calculated TCPs show that shorter delivery times lead to greater TCP, despite all delivery times being short compared to the repair half-time for sublethal lesions. Furthermore, calculated TCP(IMRT) =0.308 for the IMRT plan is smaller than TCP(3D) =0.425 for 3D conformal, even though it shows greater tumor hot spots and equal PTV coverage. The calculated TCPs are considerably lower compared to those based on the LQ model for which TCP=1 for both plans. Conclusion: The functional dependence of the voxel-by-voxel dose rate on time may be an important factor in predicting the treatment outcome and cannot be neglected in radiobiological modeling.

  7. Heavy-ion tumor therapy: Physical and radiobiological benefits

    Energy Technology Data Exchange (ETDEWEB)

    Schardt, Dieter; Elsaesser, Thilo; Schulz-Ertner, Daniela [GSI Helmholtzzentrum fuer Schwerionenforschung mbH (GSI), D-64291 Darmstadt (Germany); Markus-Krankenhaus, MVZ Radiologisches Institut, D-60431 Frankfurt/M. (Germany)

    2010-01-15

    High-energy beams of charged nuclear particles (protons and heavier ions) offer significant advantages for the treatment of deep-seated local tumors in comparison to conventional megavolt photon therapy. Their physical depth-dose distribution in tissue is characterized by a small entrance dose and a distinct maximum (Bragg peak) near the end of range with a sharp fall-off at the distal edge. Taking full advantage of the well-defined range and the small lateral beam spread, modern scanning beam systems allow delivery of the dose with millimeter precision. In addition, projectiles heavier than protons such as carbon ions exhibit an enhanced biological effectiveness in the Bragg peak region caused by the dense ionization of individual particle tracks resulting in reduced cellular repair. This makes them particularly attractive for the treatment of radio-resistant tumors localized near organs at risk. While tumor therapy with protons is a well-established treatment modality with more than 60 000 patients treated worldwide, the application of heavy ions is so far restricted to a few facilities only. Nevertheless, results of clinical phase I-II trials provide evidence that carbon-ion radiotherapy might be beneficial in several tumor entities. This article reviews the progress in heavy-ion therapy, including physical and technical developments, radiobiological studies and models, as well as radiooncological studies. As a result of the promising clinical results obtained with carbon-ion beams in the past ten years at the Heavy Ion Medical Accelerator facility (Japan) and in a pilot project at GSI Darmstadt (Germany), the plans for new clinical centers for heavy-ion or combined proton and heavy-ion therapy have recently received a substantial boost.

  8. Toxicological characteristics and primary radiobiological screening of Cystizid-M

    International Nuclear Information System (INIS)

    The toxic and radioprotective properties of the potential radioprotector of the mollecular combination Cystisid-M (cysteamine-adenosin-5'-monophosphate - CAM) were investigated. The experiments were carried out on male mice C57BI irradiated with 137Cs source. The intraperitoneal administration of 1000 mg/kg b.w. and 500 mg/kg b.w., injected 15 min prior to the irradiation with 8,5 Gr (LD90/30) was performed, and orally 3000 mg/kg b.w. and 1500 mg/kg b.w. was introduced into the stomach 45 min prior to the irradiation with 8,2 Gr (LD83/30). The radioprotective effect of CAM was recorded according to: individual survival curves up to the 30th day; the biometrical coefficients 'ALPHA' (the individual survival expectancy in the population); and S30 (the group survival expectancy). At the intraperitoneal administration of the protector the values of LD50 = 1390 mg/kg b.w. and MPD (maximum permissible dose) = 1200 mg/kg b.w. were found. At the oral administration these doses were LD50/3 = 4630 mg/kg b.w. and MPD = 3500 mg/kg b.w. It was established that CAM injected intraperitoneally in a dose of 1000 mg/kg b.w. ensured 75% survival of the protected mice against 10% of the control ones, increased the mean survival of the deceased and reduced the percentage of the animals died during the height of the bone marrow syndrome. The twofold lower dose exetted a considerably slighter effect. At oral administration the protector did not significantly modify the survival of the animals. The data obtained revealed the perspectiveness of the tested protective agent radiobiological investigations are required

  9. Radiobiological compensation: A case study of uterine cervix cancer with concurrent chemotherapy

    Science.gov (United States)

    Herrera, Higmar; Yañez, Elvia; López, Jesús

    2012-10-01

    The case of a patient diagnosed with uterine cervix cancer is presented as an example of the clinical application of the radiobiological compensation method implemented at Centro Estatal de Cancerología de Durango. Radiotherapy treatment was initially modified to compensate for the chemotherapy component and, as medical complications arose during treatment delivery resulting in an 18 days gap, new compensation followed. All physical and radiobiological assumptions to calculate the Biologically Effective Dose in the external beam and brachytherapy parts of the treatment are presented. Good local control of the tumor was achieved, the theoretical tolerance limits for the organs at risk were not surpassed and the patient manifested no extensive morbidity.

  10. Radiobiological compensation: A case study of uterine cervix cancer with concurrent chemotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Herrera, Higmar; Yanez, Elvia; Lopez, Jesus [Centro Estatal de Cancerologia de Durango, Victoria de Durango, Durango (Mexico); ISSSTE General Hospital Dr. Santiago Ramon y Cajal, Victoria de Durango, Durango (Mexico)

    2012-10-23

    The case of a patient diagnosed with uterine cervix cancer is presented as an example of the clinical application of the radiobiological compensation method implemented at Centro Estatal de Cancerologia de Durango. Radiotherapy treatment was initially modified to compensate for the chemotherapy component and, as medical complications arose during treatment delivery resulting in an 18 days gap, new compensation followed. All physical and radiobiological assumptions to calculate the Biologically Effective Dose in the external beam and brachytherapy parts of the treatment are presented. Good local control of the tumor was achieved, the theoretical tolerance limits for the organs at risk were not surpassed and the patient manifested no extensive morbidity.

  11. Actual problems of toxicology and radiobiology. Russian scientific conference with international participation. Book of abstracts

    International Nuclear Information System (INIS)

    The collection contains abstracts of the Russian scientific conference with international participation, which took place May 19-20, 2011 in St. Petersburg. Proceedings of the conference include a general description of the chemical and radiological factors of nature, questions of radiation ecology and ecotoxicology. Modern methods of toxicological and radiobiological researches, including evaluation of radiation and chemical risks, mechanisms of development, pathogenesis, clinical features, diagnosis and treatment of various forms of toxic and radiation processes are under consideration. Current approaches to prevention and early therapy of chemical and radiation injuries are given. Issues of radiation and chemical safety, as well as the problems of training in toxicology and radiobiology are discussed

  12. Skin carcinomas: Radiobiological principles, radiotherapeutic techniques and clinical management

    International Nuclear Information System (INIS)

    Purpose/Objective: The course will be divided into three major topics: (1) Review of radiobiological principles as they apply to the radiotherapeutic management of skin carcinomas: (2) review of radiotherapeutic techniques including beam qualities, beam collimation, tissue dose profiles, and the relative indications of external beam irradiation vs. brachytherapy; (3) comprehensive review of the tumor biology of skin malignancies, including malignant melanoma, and of the relative indications for radiotherapeutic and/or surgical management. (1) Review of critical data which have lead to currently applied principles of time-dose-volume concepts in the radiotherapeutic management of skin carcinomas. Emphasis will be placed on the relative importance of fraction size and overall treatment time on tumor control probability and acute and late normal tissue toxicity. (2) Considering that radiotherapy in the management of skin carcinomas is often used to minimize patient disfiguration and to preserve critical body functions (e.g. eye lids) the technical aspects of radiotherapy delivery are most critical. Careful evaluation of the extent of the lesions including evaluation of their depth of invasion will determine the quality of the radiation beams, orthovoltage and low energy electrons being the most useful. Beam harding for orthovoltage beams and secondary and tertiary (skin) collimation of appropriate electron beams are critical. For more extensive and deeply invasive lesions contour-shaping through customized bolus material is essential. Equally important is the familiarity with custom shielding of critical structures, such as eyes, ears, oral cavity and central nervous system structures. Brachytherapy applications in the treatment of skin carcinomas is limited but should be considered when implants with high dose uniformity can be constructed. (3) The discussion of clinical management will start with a discussion of tumor biological properties of the diverse malignant

  13. Skin carcinomas: radiobiological principles, radiotherapeutic techniques and clinical management

    International Nuclear Information System (INIS)

    Purpose/Objective: The course will be divided into three major topics: (1) Review of radiobiological principles as they apply to the radiotherapeutic management of skin carcinomas; (2) review of radiotherapeutic techniques including beam qualities, beam collimation, tissue dose profiles, and the relative indications of external beam irradiation vs. brachytherapy; (3) comprehensive review of the tumor biology of skin malignancies, including malignant melanoma, and of the relative indications for radiotherapeutic and/or surgical management. (1) Review of critical data which have lead to currently applied principles of time-dose-volume concepts in the radiotherapeutic management of skin carcinomas. Emphasis will be placed on the relative importance of fraction size and overall treatment time on tumor control probability and acute and late normal tissue toxicity. (2) Considering that radiotherapy in the management of skin carcinomas is often used to minimize patient disfiguration and to preserve critical body functions (e.g. eye lids) the technical aspects of radiotherapy delivery are most critical. Careful evaluation of the extent of the lesions including evaluation of their depth of invasion will determine the quality of the radiation beams, orthovoltage and low energy electrons being the most useful. Beam harding for orthovoltage beams and secondary and tertiary (skin) collimation of appropriate electron beams are critical. For more extensive and deeply invasive lesions contour-shaping through customized bolus material is essential. Equally important is the familiarity with custom shielding of critical structures, such as eyes, ears, oral cavity and central nervous system structures. Brachytherapy applications in the treatment of skin carcinomas is limited but should be considered when implants with high dose uniformity can be constructed. (3) The discussion of clinical management will start with a discussion of tumor biological properties of the diverse malignant

  14. Skin carcinomas: Radiobiological principles, radiotherapeutic techniques and clinical management

    International Nuclear Information System (INIS)

    Purpose/Objective: The course will be divided into three major topics: (1) Review of radiobiological principles as they apply to the radiotherapeutic management of skin carcinomas; (2) review of radiotherapeutic techniques including beam qualities, beam collimation, tissue dose profiles, and the relative indications of external beam irradiation vs. brachytherapy; (3) comprehensive review of the tumor biology of skin malignancies, including malignant melanoma, and of the relative indications for radiotherapeutic and/or surgical management. (1) Review of critical data which have led to currently applied principles of time-dose-volume concepts in the radiotherapeutic management of skin carcinomas. Emphasis will be placed on the relative importance of fraction size and overall treatment time on tumor control probability and acute and late normal tissue toxicity. (2) Considering that radiotherapy in the management of skin carcinomas is often used to minimize patient disfiguration and to preserve critical body functions (e.g. eye lids) the technical aspects of radiotherapy delivery are most critical. Careful evaluation of the extent of the lesions including evaluation of their depth of invasion will determine the quality of the radiation beams, orthovoltage and low energy electrons being the most useful. Beam harding for orthovoltage beams and secondary and tertiary (skin) collimation of appropriate electron beams are critical. For more extensive and deeply invasive lesions contour-shaping through customized bolus material is essential. Equally important is the familiarity with custom shielding of critical structures, such as eyes, ears, oral cavity and central nervous system structures. Brachytherapy applications in the treatment of skin carcinomas is limited but should be considered when implants with high dose uniformity can be constructed. (3) The discussion of clinical management will start with a discussion of properties and routes of spread of the diverse

  15. Experimental radiotherapy and clinical radiobiology. Vol. 8, special issue 1. Proceedings

    International Nuclear Information System (INIS)

    The publication contains the abstracts of all papers and posters presented at the symposium. The headings were as follows: Radiobiology of the lung, mediation of radiation damage in the lung, clinical studies, future clinical directions, as well as documentation and management. (MG)

  16. Radiological and Environmental Research Division, Center for Human Radiobiology. Annual report, July 1980-June 1981

    International Nuclear Information System (INIS)

    Separate abstracts were prepared for the 22 papers of this annual report of the Center for Human Radiobiology. Abstracts were not written for 2 appendices which contain data on the exposure and radium-induced malignancies of 2259 persons whose radium content has been determined at least once

  17. IAEA advisory group meeting on nuclear and atomic data for radiotherapy and related radiobiology in co-operation with the Radiobiological Institute of the Division for Health Research TNO, 16-20 September 1985, Rijswijk, the Netherlands

    International Nuclear Information System (INIS)

    The IAEA Advisory Group Meeting on ''Nuclear and Atomic Data for Radiotherapy and Related Radiobiology'' was held at Rijswijk, the Netherlands, from 16 to 20 September 1985, in co-operation with the Radiobiological Institute TNO. The meeting participants reviewed the current and future requirements on nuclear and atomic data for radiotherapy and radiobiology, identified data requirements and their priorities, and issued a number of specific recommendations for future technical work in nuclear and atomic data required to establish a more solid nuclear physics foundation of radiotherapy and related radiobiology. The recommendations in this report are directed to three areas, namely beam production and field description, dosimetry, and interpretation and optimization of biological effects. The final proceedings will be issued as an IAEA publication in 1986. (author)

  18. HIRFL-CSR physics program

    International Nuclear Information System (INIS)

    The research activities at HIRFL-CSR cover the fields of the radio-biology, material science, atomic physics, and nuclear physics. This talk will mainly concentrate on the program on nuclear physics with the existing and planned experimental setups at HIRFL-CSR. (author)

  19. Paul Scherrer Institut annual report 1995. Annex II: PSI life sciences and institute for medical radiobiology newsletter 1995

    International Nuclear Information System (INIS)

    The newsletter presents the 1995 progress report of PSI F2-Department and of the Institute for Medical Radiobiology in the fields of radiation medicine, radiopharmacy and radiation hygiene. figs., tabs., refs

  20. Paul Scherrer Institut annual report 1995. Annex II: PSI life sciences and institute for medical radiobiology newsletter 1995

    Energy Technology Data Exchange (ETDEWEB)

    Blaeuenstein, P.; Gschwend, B. [eds.

    1996-09-01

    The newsletter presents the 1995 progress report of PSI F2-Department and of the Institute for Medical Radiobiology in the fields of radiation medicine, radiopharmacy and radiation hygiene. figs., tabs., refs.

  1. Paul Scherrer Institut annual report 1996. Annex II: PSI life sciences and Institute for Medical Radiobiology Newsletter 1996

    International Nuclear Information System (INIS)

    This annex to the PSI Annual Report 1996 reports on the progress achieved by the PSI Department II during 1996 in the fields of radiation medicine, radiopharmacy, radiation hygiene, positron emission tomography and medical radiobiology. figs., tab., refs

  2. Activities of the radiobiological institute, the institute for experimental gerontology, and the primate center. Annual report, 1976

    International Nuclear Information System (INIS)

    Activities, presented by way of concise articles, cover the following subjects: radiation physics, radiobiology, experimental tumor therapy, tumor induction and tumor biology, immunology, transplantation and immunogenetics, hematology, gerontology, ethology, microbiology and quotobiology, techniques, and animals

  3. Radiobiological effects in small mammals populations dwelled at radioactive waste disposal sites

    International Nuclear Information System (INIS)

    A major issue in evaluating the ecological acceptability of a disposal system for radioactive waste is in preventing the ecological risk that may arise from exposures in the distant future. There is uncertainty surrounding any estimate of these doses or risks due to lack of knowledge about future conditions. Therefore, the adequate estimation of the ecological acceptability of a radioactive waste disposal system required a complex radioecological and radiobiological approach. Environmental surveillance at the Sergievo-Posadsky radioactive waste disposal system of the Scientific and Industrial Association Radon in additional to a standard complex radiological testing includes also the study of the radiobiological effects in different biological objects sampled from the contaminated areas. In present report the results obtained on small rodents (mice and voles) sampled from the strict mode and fence zones of this disposal system are displayed and discussed. (author)

  4. Ill-posed problem and regularization in reconstruction of radiobiological parameters from serial tumor imaging data

    International Nuclear Information System (INIS)

    The main objective of this article is to improve the stability of reconstruction algorithms for estimation of radiobiological parameters using serial tumor imaging data acquired during radiation therapy. Serial images of tumor response to radiation therapy represent a complex summation of several exponential processes as treatment induced cell inactivation, tumor growth rates, and the rate of cell loss. Accurate assessment of treatment response would require separation of these processes because they define radiobiological determinants of treatment response and, correspondingly, tumor control probability. However, the estimation of radiobiological parameters using imaging data can be considered an inverse ill-posed problem because a sum of several exponentials would produce the Fredholm integral equation of the first kind which is ill posed. Therefore, the stability of reconstruction of radiobiological parameters presents a problem even for the simplest models of tumor response. To study stability of the parameter reconstruction problem, we used a set of serial CT imaging data for head and neck cancer and a simplest case of a two-level cell population model of tumor response. Inverse reconstruction was performed using a simulated annealing algorithm to minimize a least squared objective function. Results show that the reconstructed values of cell surviving fractions and cell doubling time exhibit significant nonphysical fluctuations if no stabilization algorithms are applied. However, after applying a stabilization algorithm based on variational regularization, the reconstruction produces statistical distributions for survival fractions and doubling time that are comparable to published in vitro data. This algorithm is an advance over our previous work where only cell surviving fractions were reconstructed. We conclude that variational regularization allows for an increase in the number of free parameters in our model which enables development of more

  5. Radiobiological work using a negative pion beam at the Rutherford Laboratory 1971-76

    International Nuclear Information System (INIS)

    The subject is discussed in two sections: physics experiments (including, inter alia, dose measurement, LET distribution, radiation products of spallation); radiobiological studies (including separate reports as follows: review of experimental programme; some in vivo effects of negative pions in mice; survival and recovery of Hela cells in vitro; negative pion dose-response curves for frozen Hela cells; response of vicia faba to irradiation with negative pions; pion experiments with chromosome aberrations). (U.K.)

  6. Radiobiological investigations of the accelerators at the Joint Institute for Nuclear Research

    International Nuclear Information System (INIS)

    Full text: The Joint Institute for Nuclear Research (JINR) has the different accelerators of heavy charged particles for various energies. The radiobiological investigations at these machines have been commenced some tens years ago. The main task of scientific research at the Laboratory of Radiation Biology of JINR is connected with investigations of genetic effects of accelerated charged particles with wide spectrum of energies. Using accelerated heavy ions with low energy, the following directions of researches in radiobiology and radiation genetics were performed: study of RBE problem in connection with DNA repair processes; investigation of the molecular mechanisms of point and structural mutation induction in prokaryotic cells and the influence of the repair systems on the mutagenic processes after irradiation in a wide range of linear energy transfer (LET); study of the SOS-response of bacterial cells by using SOS-chromo test, SOS-lux test and by criteria of α-prophage induction in lysogenic bacteria after irradiation by heavy ions; study of the regularities of gene mutation inductions in yeast cells under action of ionizing radiation with different LET; investigations of the regularities of unstable and stable chromosomal aberrations (translocations) in human cells under action of ionizing radiation with wide LET range; study of mutagenic (HPRT gene) effects in mammalian cells in culture after heavy charged particle irradiation and chromosomal instability in HPRT-mutant clones after irradiation; study of the cytogenetic effects in mammalian cells irradiated by heavy ions in low doses. The radiobiological investigations with high energy are carried out at the Nuclotron - the new JINR accelerator. The programme involves the most vital tasks of modern radiobiology: study of the regularities and mechanisms of stable and unstable chromosome aberration induction in human cells; genetic control of check-point regulation in low eukaryotic cells; study of the

  7. Radiobiological impact of dose calculation algorithms on biologically optimized IMRT lung stereotactic body radiation therapy plans

    OpenAIRE

    Liang, X.; Penagaricano, J.; Zheng, D.; Morrill, S.; Zhang, X; Corry, P.; Griffin, R. J.; Han, E. Y.; Hardee, M.; Ratanatharathom, V.

    2016-01-01

    Background The aim of this study is to evaluate the radiobiological impact of Acuros XB (AXB) vs. Anisotropic Analytic Algorithm (AAA) dose calculation algorithms in combined dose-volume and biological optimized IMRT plans of SBRT treatments for non-small-cell lung cancer (NSCLC) patients. Methods Twenty eight patients with NSCLC previously treated SBRT were re-planned using Varian Eclipse (V11) with combined dose-volume and biological optimization IMRT sliding window technique. The total dos...

  8. Installation of a flow cytometry facility and some applications in radiobiology

    International Nuclear Information System (INIS)

    Flow cytometry has enormous potential in many areas of experimental pathology. Details of the installation and commissioning of a flow cytometer at the Harwell Laboratory are described. Following an explanation of the principles of flow cytometry, several applications to specific problems in radiobiology are discussed. Also included are results of some preliminary studies with the Harwell flow cytometer on samples such as blood, bone marrow, macrophages and cell cultures, and a discussion of future applications. (author)

  9. A community call for a dedicated radiobiological research facility to support particle beam cancer therapy

    DEFF Research Database (Denmark)

    Holzscheiter, Michael H.; Bassler, Niels; Dosanjh, Manjit;

    2012-01-01

    Recently more than one hundred researchers followed an invitation to a brainstorming meeting on the topic of a future dedicated radio-biological and radio-physical research center. 100 more joint the meeting via webcast. After a day of presentations and discussions it was clear, that an urgent ne...... for such a development exists, resulting in a community call for the construction of a dedicated laboratory. Below we comment on the essential points....

  10. [From microdosimetry to nanodosimetry--the link between radiobiology and radiation physics].

    Science.gov (United States)

    Fu, Yuchuan; Li, Ping

    2014-06-01

    The link between micro- and macro-parameters for radiation interactions that take place in living biological systems is described in this paper. Meanwhile recent progress and development in microdosimetry and nanodosimetry are introduced, including the methods to measure and calculate these micro- or nano-parameters. The relationship between radiobiology and physical quantities in microdosimetry and nanodosimetry was presented. Both the current problems on their applications in radiation protection and radiotherapy and the future development direction are proposed. PMID:25219261

  11. Heavy Charged Particle Radiobiology: Using Enhanced Biological Effectiveness and Improved Beam Focusing to Advance Cancer Therapy

    OpenAIRE

    Allen, Christopher; Borak, Thomas B.; Tsujii, Hirohiko; Jac A Nickoloff

    2011-01-01

    Ionizing radiation causes many types of DNA damage, including base damage and single- and double-strand breaks. Photons, including X-rays and γ-rays, are the most widely used type of ionizing radiation in radiobiology experiments, and in radiation cancer therapy. Charged particles, including protons and carbon ions, are seeing increased use as an alternative therapeutic modality. Although the facilities needed to produce high energy charged particle beams are more costly than photon facilitie...

  12. Ill-posed problem and regularization in reconstruction of radiobiological parameters from serial tumor imaging data

    Science.gov (United States)

    Chvetsov, Alevei V.; Sandison, George A.; Schwartz, Jeffrey L.; Rengan, Ramesh

    2015-11-01

    The main objective of this article is to improve the stability of reconstruction algorithms for estimation of radiobiological parameters using serial tumor imaging data acquired during radiation therapy. Serial images of tumor response to radiation therapy represent a complex summation of several exponential processes as treatment induced cell inactivation, tumor growth rates, and the rate of cell loss. Accurate assessment of treatment response would require separation of these processes because they define radiobiological determinants of treatment response and, correspondingly, tumor control probability. However, the estimation of radiobiological parameters using imaging data can be considered an inverse ill-posed problem because a sum of several exponentials would produce the Fredholm integral equation of the first kind which is ill posed. Therefore, the stability of reconstruction of radiobiological parameters presents a problem even for the simplest models of tumor response. To study stability of the parameter reconstruction problem, we used a set of serial CT imaging data for head and neck cancer and a simplest case of a two-level cell population model of tumor response. Inverse reconstruction was performed using a simulated annealing algorithm to minimize a least squared objective function. Results show that the reconstructed values of cell surviving fractions and cell doubling time exhibit significant nonphysical fluctuations if no stabilization algorithms are applied. However, after applying a stabilization algorithm based on variational regularization, the reconstruction produces statistical distributions for survival fractions and doubling time that are comparable to published in vitro data. This algorithm is an advance over our previous work where only cell surviving fractions were reconstructed. We conclude that variational regularization allows for an increase in the number of free parameters in our model which enables development of more

  13. Fast neutrons set the pace. [Radiobiological investigations with fast neutrons at the CSIR cyclotron in Pretoria

    Energy Technology Data Exchange (ETDEWEB)

    Hough, J.H.; Slabbert, J.P. (Council for Scientific and Industrial Research, Pretoria (South Africa). National Accelerator Centre)

    1985-01-01

    Radiobiological investigations with fast neutrons have been initiated at the CSIR cyclotron in Pretoria. It was proposed some years ago to create a neutron therapy facility using the CSIR cyclotron. Neutrons are classified as high linear energy transfer (LET) particles. Biological damage occurring in tissue is a direct function of the LET of the incident radiation. To quantify the biological effects of different types of radiation on mammalian cells, several procedures and concepts have evolved from radiobiological research. Probably the most significant laboratory techniques developed, were the derivation of cell survival curves which are obtained by determining the number of cell colonies that have survived a certain radiation dose. A semi-logarithmic plot of surviving fraction versus the absorbed dose yields the survival curve. Dose modifying factors such as the relative biological effectiveness (RBE) of the radiation can be quantified in terms of this relationship. A radiobiological programme has to be undertaken before patients can receive neutron therapy at the CSIR cyclotron. The article is a discussion of this programme.

  14. The European Radiobiology Archives (ERA) - Content, structure and use illustrated by an example

    International Nuclear Information System (INIS)

    The European Radiobiology Archives (ERA), supported by the European Commission and the European Late Effect Project Group (EULEP), together with the US National Radiobiology Archives (NRA) and the Japanese Radiobiology Archives (JRA) have collected all information still available on long-term animal experiments, including some selected human studies. The archives consist of a database in Microsoft Access, a web site, databases of references and information on the use of the database. At present, the archives contain a description of the exposure conditions, animal strains, etc. from ∼350,000 individuals; data on survival and pathology are available from ∼200,000 individuals. Care has been taken to render pathological diagnoses compatible among different studies and to allow the lumping of pathological diagnoses into more general classes. 'Forms' in Access with an underlying computer code facilitate the use of the database. This paper describes the structure and content of the archives and illustrates an example for a possible analysis of such data. (authors)

  15. SU-E-T-275: Radiobiological Evaluation of Intensity Modulated Radiotherapy Treatment for Locally Advanced Head and Neck Squamous Cell Carcinomas

    International Nuclear Information System (INIS)

    Purpose: To evaluate the radiobiological outcome of Intensity Modulated Radiotherapy Treatment (IMRT) for locally advanced head and neck squamous cell carcinomas using HART (Histogram Analysis in Radiation Therapy; J Appl Clin Med Phys 11(1): 137–157, 2010) program and compare with the clinical outcomes. Methods: We have treated 20 patients of stage III and IV HNSCC Oropharynx and hypopharynx with accelerated IMRT technique and concurrent chemotherapy. Delineation of tumor and normal tissues were done using Danish Head and Neck Cancer Group (DAHANCA) contouring guidelines and radiotherapy was delivered to a dose of 70Gy in 35 fractions to the primary and involved lymph nodes, 63Gy to intermediate risk areas and 56 Gy to lower risk areas, Monday to Saturday, 6 Days/week using 6 MV Photons with an expected overall treatment time of 6 weeks. The TCP and NTCP's were calculated from the dose-volume histogram (DVH) statistics using the Poisson Statistics (PS) and JT Lyman models respectively and the Resultwas correlated with clinical outcomes of the patients with mean follow up of 24 months. Results: Using HART program, the TCP (0.89± 0.01) of primary tumor and the NTCP for parotids (0.20±0.12), spinal cord (0.05±0.01), esophagus (0.30±0.2), mandible (0.35±0.21), Oral cavity (0.37±0.18), Larynx (0.30±0.15) were estimated and correlated with clinical outcome of the patients. Conclusion: Accelerated IMRT with Chemotherapy is a clinical feasible option in the treatment of locally advanced HNSCC with encouraging initial tumour response and acceptable acute toxicities. The correlation between the clinical outcomes and radiobiological model estimated parameters using HART programs are found to be satisfactory

  16. SU-E-T-275: Radiobiological Evaluation of Intensity Modulated Radiotherapy Treatment for Locally Advanced Head and Neck Squamous Cell Carcinomas

    Energy Technology Data Exchange (ETDEWEB)

    Rekha Reddy, B.; Ravikumar, M.; Tanvir Pasha, C.R; Anil Kumar, M.R; Varatharaj, C. [Kidwai Memorial Institute of Oncology Bangalore, Karnataka (India); Pyakuryal, A [University Illinois at Chicago, Chicago, IL (United States); Narayanasamy, Ganesh [UTHSCSA, San Antonio, TX (United States)

    2014-06-01

    Purpose: To evaluate the radiobiological outcome of Intensity Modulated Radiotherapy Treatment (IMRT) for locally advanced head and neck squamous cell carcinomas using HART (Histogram Analysis in Radiation Therapy; J Appl Clin Med Phys 11(1): 137–157, 2010) program and compare with the clinical outcomes. Methods: We have treated 20 patients of stage III and IV HNSCC Oropharynx and hypopharynx with accelerated IMRT technique and concurrent chemotherapy. Delineation of tumor and normal tissues were done using Danish Head and Neck Cancer Group (DAHANCA) contouring guidelines and radiotherapy was delivered to a dose of 70Gy in 35 fractions to the primary and involved lymph nodes, 63Gy to intermediate risk areas and 56 Gy to lower risk areas, Monday to Saturday, 6 Days/week using 6 MV Photons with an expected overall treatment time of 6 weeks. The TCP and NTCP's were calculated from the dose-volume histogram (DVH) statistics using the Poisson Statistics (PS) and JT Lyman models respectively and the Resultwas correlated with clinical outcomes of the patients with mean follow up of 24 months. Results: Using HART program, the TCP (0.89± 0.01) of primary tumor and the NTCP for parotids (0.20±0.12), spinal cord (0.05±0.01), esophagus (0.30±0.2), mandible (0.35±0.21), Oral cavity (0.37±0.18), Larynx (0.30±0.15) were estimated and correlated with clinical outcome of the patients. Conclusion: Accelerated IMRT with Chemotherapy is a clinical feasible option in the treatment of locally advanced HNSCC with encouraging initial tumour response and acceptable acute toxicities. The correlation between the clinical outcomes and radiobiological model estimated parameters using HART programs are found to be satisfactory.

  17. Development of a compact laser-produced plasma soft X-ray source for radiobiology experiments

    Science.gov (United States)

    Adjei, Daniel; Ayele, Mesfin Getachew; Wachulak, Przemyslaw; Bartnik, Andrzej; Wegrzynski, Łukasz; Fiedorowicz, Henryk; Vyšín, Luděk; Wiechec, Anna; Lekki, Janusz; Kwiatek, Wojciech M.; Pina, Ladislav; Davídková, Marie; Juha, Libor

    2015-12-01

    A desk-top laser-produced plasma (LPP) source of soft X-rays (SXR) has been developed for radiobiology research. The source is based on a double-stream gas puff target, irradiated with the focused beam of a commercial Nd:YAG laser. The source has been optimized to get a maximum photon emission from LPP in the X-ray "water window" spectral wavelength range from 2.3 nm (i.e., an absorption edge of oxygen) to 4.4 nm (i.e., an absorption edge of carbon) (280-540 eV in photon energy units) by using argon gas-puff target and spectral filtering by free-standing thin foils. The present source delivers nanosecond pulses of soft X-rays at a fluence of about 4.2 × 103 photons/μm2/pulse on a sample placed inside the vacuum chamber. In this paper, the source design, radiation output characterization measurements and initial irradiation experiments are described. The source can be useful in addressing observations related to biomolecular, cellular and organisms' sensitivity to pulsed radiation in the "water window", where carbon atoms absorb X-rays more strongly than the oxygen, mostly present in water. The combination of the SXR source and the radiobiology irradiation layout, reported in this article, make possible a systematic investigation of relationships between direct and indirect action of ionizing radiation, an increase of a local dose in carbon-rich compartments of the cell (e.g., lipid membranes), an experimental estimation of a particular role of the Auger effect (in particular in carbon atoms) in the damage to biological systems, and the study of ionization/excitation-density (LET - Linear Energy Transfer) and dose-rate effects in radiobiology.

  18. Estimation of Radiobiologic Parameters and Equivalent Radiation Dose of Cytotoxic Chemotherapy in Malignant Glioma

    International Nuclear Information System (INIS)

    Purpose: To determine the radiobiologic parameters for high-grade gliomas. Methods and Materials: The biologic effective dose concept is used to estimate the α/β ratio and K (dose equivalent for tumor repopulation/d) for high-grade glioma patients treated in a randomized fractionation trial. The equivalent radiation dose of temozolomide (Temodar) chemotherapy was estimated from another randomized study. The method assumes that the radiotherapy biologic effective dose is proportional to the adjusted radiotherapy survival duration of high-grade glioma patients. Results: The median tumor α/β and K estimate is 9.32 Gy and 0.23 Gy/d, respectively. Using the published surviving fraction after 2-Gy exposure (SF2) data, and the above α/β ratio, the estimated median α value was 0.077 Gy-1, β was 0.009 Gy-2, and the cellular doubling time was 39.5 days. The median equivalent biologic effective dose of temozolomide was 11.03 Gy9.3 (equivalent to a radiation dose of 9.1 Gy given in 2-Gy fractions). Random sampling trial simulations based on a cure threshold of 70 Gy in high-grade gliomas have shown the potential increase in tumor cure with dose escalation. Partial elimination of hypoxic cells (by chemical hypoxic cell sensitizers or carbon ion therapy) has suggested that considerable gains in tumor control, which are further supplemented by temozolomide, are achievable. Conclusion: The radiobiologic parameters for human high-grade gliomas can be estimated from clinical trials and could be used to inform future clinical trials, particularly combined modality treatments with newer forms of radiotherapy. Other incurable cancers should be studied using similar radiobiologic analysis

  19. SU-E-T-194: From Dicom-RT to Radiobiological Dose Metrics in 5 Minutes

    Energy Technology Data Exchange (ETDEWEB)

    Whelan, B; Holloway, L

    2014-06-01

    Purpose: To develop a flexible and standalone framework for batch calculation of radiobiological dose metrics from Dicom-RT. Methods: Software has been developed which allows (1) The calculation of DVH data from DICOM dose and structure files (DVHgenerator), (2) Calculation of a wide range of radiobiological metrics from this data (CompPlanGui). Both these tools are run via graphical user interface (GUI), making them fast and simple. Part 1 is a new tool which has not previously been published, whilst part 2 is a GUI overlay for the previously published software ‘Comp-Plan’ (Holloway et. al., Medical Dosimetry, 2012), previously reliant on command line interface. The time taken for an experienced user to evaluate a test case of 6 plans with and without CompPlanGUI was quantified. Results: The DVH-generator has been found to be faster, more robust and require far less physical memory then using alternative software solutions for the same purpose. The Comp Plan GUI significantly reduces the amount of time required to set up a base directory, eliminates code crashes arising from typographical errors, and renders the code far more accessible to non-expert users. It took an experienced user of the code around 3 minutes to set up a base directory of 6 plans compared around 8 minutes without, indicating that using CompPlanGUI reduced setup time by over 50%. Conclusion: A standalone GUI based framework has developed which allows for the batch calculation of radiobiological dose metrics directly from Dicom-RT files. As with the original code, this work will be made freely available on request, as well as via matlab file exchange.

  20. SU-E-T-194: From Dicom-RT to Radiobiological Dose Metrics in 5 Minutes

    International Nuclear Information System (INIS)

    Purpose: To develop a flexible and standalone framework for batch calculation of radiobiological dose metrics from Dicom-RT. Methods: Software has been developed which allows (1) The calculation of DVH data from DICOM dose and structure files (DVHgenerator), (2) Calculation of a wide range of radiobiological metrics from this data (CompPlanGui). Both these tools are run via graphical user interface (GUI), making them fast and simple. Part 1 is a new tool which has not previously been published, whilst part 2 is a GUI overlay for the previously published software ‘Comp-Plan’ (Holloway et. al., Medical Dosimetry, 2012), previously reliant on command line interface. The time taken for an experienced user to evaluate a test case of 6 plans with and without CompPlanGUI was quantified. Results: The DVH-generator has been found to be faster, more robust and require far less physical memory then using alternative software solutions for the same purpose. The Comp Plan GUI significantly reduces the amount of time required to set up a base directory, eliminates code crashes arising from typographical errors, and renders the code far more accessible to non-expert users. It took an experienced user of the code around 3 minutes to set up a base directory of 6 plans compared around 8 minutes without, indicating that using CompPlanGUI reduced setup time by over 50%. Conclusion: A standalone GUI based framework has developed which allows for the batch calculation of radiobiological dose metrics directly from Dicom-RT files. As with the original code, this work will be made freely available on request, as well as via matlab file exchange

  1. Controlling radioactive waste disposal: the work of the Fisheries Radiobiological Laboratory

    International Nuclear Information System (INIS)

    The Fisheries Radiobiological Laboratory (FRL) is based at Lowestoft and forms the Aquatic Environment Protection Division 1, within the Directorate of Fisheries Research of the Ministry of Agriculture, Fisheries and Food. The FRL undertakes a range of duties throughout the UK, and is primarily concerned with liquid wastes to the sea, and surface waters and solid wastes dumped at sea. Summaries are given of the work, responsibilities and interests of the three groups within FRL (Radiological Control, Research and Supporting Services). (U.K.)

  2. Physical and cellular radiobiological properties of heavy ions in relation to cancer therapy applications

    International Nuclear Information System (INIS)

    A variety of experiments have been carried out in vitro on several mammalian cell lines with carbon, neon, silicon and argon beams at 14 and 24 cm depth penetration. The results of these experiments substantiate the conceptual basis for physical and radiobiological advantages of accelerated heavy-ion beams in cancer therapy. The best biologically effective depth dose ratio for situations corresponding to therapy needs can be obtained with accelerated carbon beams. The depression of the oxygen effect with silicon or argon ion beams is greater than that achievable with neutrons or pions, or with heavy ions of lower atomic number

  3. Experimental radiotherapy and clinical radiobiology. Vol. 22. Proceedings; Experimentelle Strahlentherapie und Klinische Strahlenbiologie. Bd. 22. Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Baumann, Michael; Cordes, Nils; Dikomey, Ekkehard; Krause, Mechthild; Petersen, Cordula; Rodemannn, H. Peter; Zips, Daniel (eds.)

    2013-03-01

    The proceedings of the 22th Symposium on experimental radiotherapy and clinical radiotherapy contain lectures and poster on the following issues: Radiation induced immuno-targeting of tumors; targeting in the radiotherapy; biomarkers; targeting; radio-oncological therapy of rectal carcinoma - contribution of radiobiology for therapy optimization; biomarkers for radiation sensibility; resistance mechanisms of tumors; resistance mechanisms of normal tissue; micro ambience, P13L inhibition in radiotherapy: improvement of the local tumor control by molecular mechanisms or the influence of the tumor micro-ambience? DNA repair; radiation effects and technical development.

  4. Radiobiological and radioecological studies with the unicellular marine algae Acetabularia, Batophora and Dunaliella

    International Nuclear Information System (INIS)

    Radiobiological studies of the biological and chemical effects of X-rays on the marine algae Acetabularia and Batophora and the incorporation of 3H in Acetabularia and Dunaliello were performed. It was shown that the main morphogenetic process of Acetabularia and Batophora are affected by the radiations. Experiments with tritiated water revealed that Acetabularia cells are unable to concentrate 3H. However, a significant amount of this radionuclide is incorporated into the genetic material of the cells. When organically bound 3H is supplied to Acetabularia or Dunaliello, a selective accumulation of some substances is observed. (H.K.)

  5. Nuclear Physics and Radiobiology - Issues for Humans in Space and on Earth

    Science.gov (United States)

    Tripathi, Ram

    2008-10-01

    Nuclear physics is playing a vital role in human biological applications, specifically in planned space missions, in hadron radiotherapy, and in low dose radiobiology. While seemingly disparate, these and other areas share a common need for the understanding of nuclear interactions in biological systems. Radiobiology continues to provide valuable information that will help develop better methods for using radiation in the treatment of disease as well as provide a scientific basis for radiation protection standards. NASA is now focused on the agency's vision for space exploration encompassing a broad range of human and robotic missions including missions to the Moon, Mars and beyond. As a result, there is a focus on long duration space missions. Protection from hazards of space radiation has been identified as one of the five NASA critical areas for human space flight. The cost effective design of spacecraft demands a very stringent requirement on the optimization process. Exposures from the hazards of severe space radiation in deep space and/or long duration missions are very different from that of low earth orbit, and much needs to be done about their effects. However, it is clear that revolutionary technologies will need to be developed. Here on earth, particulate radiation treatment for cancer, such as proton radiotherapy, is playing an increasing important role, while the biological effectiveness remains less well understood than for x-rays and other forms of medical radiation treatments. Advanced imaging, dosimetric, Monte Carlo, and other techniques from nuclear physics are utilized to study the molecular basis of fractionation dependency and other tumor and normal tissue radiation responses, such as radiosensitivity. Moreover, advances developed by biological research efforts, such as the sequencing of the human genome, have opened new horizons for radiobiology. New techniques have made it possible to determine at the cellular / molecular level how living

  6. Experimental radiotherapy and clinical radiobiology. Vol. 22. Proceedings; Experimentelle Strahlentherapie und Klinische Strahlenbiologie. Bd. 25. Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Baumann, Michael; Krause, Mechthild [Universitaetsklinikum Technische Univ. Dresden (Germany). Klinik und Poliklinik fuer Strahlentherapie und Radiologie; Cordes, Nils [Universitaetsklinikum Technische Univ. Dresden (Germany). OncoRay - Nationales Zentrum fuer Strahlenforschung in der Radioonkologie; Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany); Petersen, Cordula [Universitaetsklinikum Hamburg-Eppendorf, Hamburg (Germany). Klinik und Poliklinik fuer Strahlentherapie und Radioonkologie; Rodemann, H. Peter [Universitaetsklinikum Tuebingen (Germany). Sektion fuer Strahlenbiologie; Rothkamm, Kai [Universitaetsklinikum Hamburg-Eppendorf, Hamburg (Germany). Lab. fuer Strahlentherapie und Experimentelle Radioonkologie; Zips, Daniel (ed.) [Tuebingen Univ. (Germany). Universitaetsklinik fuer Radioonkologie

    2016-05-01

    The proceedings of the 25th symposium on experimental radiotherapy and clinical radiobiology include papers on the following issues: radiotherapy individualization based on imaging; pre-clinic imaging and new experimental methods; methods and models, micromilieu and metabolism, combined therapy; secondary tumors following radiotherapy; radiogenic effects in normal tissue; resistance mechanism of tumors and normal tissue; personalized radio-oncology - which biological data are needed; pre-clinic and personalized radio-oncology; biomarkers - pre-clinic and translational; translational examinations for personalized radio-oncology.

  7. Extrapolation ionisation chamber measurements on beta-emitting sources produced for the CEGB collaborative radiobiology programme

    International Nuclear Information System (INIS)

    This report describes the structure and application of an extrapolation ionisation chamber used for measuring dose-rates from plane and point beta-emitting sources. These measurements form the basis of the dosimetry for a collaborative radiobiological study of skin to study both stochastic and non-stochastic effects. A small sample from the wide range of measurements undertaken in the programme has been selected to illustrate the procedures involved. The extrapolation chamber is currently being automated and it is intended that this report should provide a source reference to the basis of the measurements made between 1977-86. (author)

  8. Environmental Research Division annual report: Center for Human Radiobiology, July 1982-June 1983

    International Nuclear Information System (INIS)

    This is the fourteenth Annual Report of the Center for Human Radiobiology. New cases of bone cancer and carcinoma of head sinuses are occurring at a rate of about one per year in patients who acquired radium burdens 50 to 60 years ago. Several papers deal with dosimetry of alpha-emitting radionuclides in man, in animals, or in the environment. The report concludes with an appendix containing data on the exposure of 2312 persons whose radium content has been determined and an appendix listing the classical radium-related malignancies (osteosarcomas and carcinomas of the paranasal sinuses and mastoid)

  9. Dictionary of radiation protection, radiobiology and nuclear medicine. English-German-French-Russian

    International Nuclear Information System (INIS)

    This multilingual dictionary covers the subject fields of radiation protection, radiobiology, and nuclear medicine with about 12,000 terms in each language. All terms are supplemented by one or more abbreviations of 22 special branches to assure the use of the very relevant terms. Special branches listed are for instance decontamination, dosimetry, atomic legislation, radiation detectors, radiography (medical), radiotherapy, safeguards, shielding, tansportation and storage. The terminology used in the International Nuclear Information System (INIS) of the IAEA has been completely taken into account

  10. Development of a compact laser-produced plasma soft X-ray source for radiobiology experiments

    Czech Academy of Sciences Publication Activity Database

    Adjei, D.; Ayele, M.G.; Wachulak, P.; Bartnik, A.; Wegrzynski, L.; Fiedorowicz, H.; Vyšín, Luděk; Wiechec, A.; Lekki, J.; Kwiatek, W.M.; Pina, L.; Davídková, Marie; Juha, Libor

    2015-01-01

    Roč. 364, Dec (2015), s. 27-32. ISSN 0168-583X R&D Projects: GA ČR(CZ) GBP108/12/G108; GA ČR GA13-28721S EU Projects: European Commission(XE) 284464 - LASER LAB-EUROPE Institutional support: RVO:68378271 ; RVO:61389005 Keywords : laser -produced plasma * soft X-rays * radiobiology * gas puff target * water window Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 1.124, year: 2014

  11. Tcp and NTCP radiobiological models: conventional and hypo fractionated treatments in radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Astudillo V, A.; Paredes G, L. [ININ, Carretera Mexico-Toluca s/n, Ocoyoacac 52750, Estado de Mexico (Mexico); Resendiz G, G.; Posadas V, A. [Hospital Angeles Lomas, Av. Vialidad de la Barranca s/n, Col. Valle de las Palmas, 52763 Huixquilucan de Degallado, Estado de Mexico (Mexico); Mitsoura, E. [Universidad Autonoma del Estado de Mexico, Facultad de Medicina, Paseo Tollocan, Esq. Jesus Carranza s/n, Col. Moderna de la Cruz, 50180 Toluca, Estado de Mexico (Mexico); Rodriguez L, A.; Flores C, J. M., E-mail: armando.astudillo@inin.gob.mx [Hospital Medica Sur, Puente de Piedra 150, Col. Toriello Guerra, 14050 Tlalpan, Mexico D. F. (Mexico)

    2015-10-15

    The hypo and conventional fractionated schedules performance were compared in terms of the tumor control and the normal tissue complications. From the records of ten patients, treated for adenocarcinoma and without mastectomy, the dose-volume histogram was used. Using radiobiological models the probabilities for tumor control and normal tissue complications were calculated. For both schedules the tumor control was approximately the same. However, the damage in the normal tissue was larger in conventional fractionated schedule. This is important because patients assistance time to their fractions (15 fractions/25 fractions) can be optimized. Thus, the hypo fractionated schedule has suitable characteristics to be implemented. (Author)

  12. Tcp and NTCP radiobiological models: conventional and hypo fractionated treatments in radiotherapy

    International Nuclear Information System (INIS)

    The hypo and conventional fractionated schedules performance were compared in terms of the tumor control and the normal tissue complications. From the records of ten patients, treated for adenocarcinoma and without mastectomy, the dose-volume histogram was used. Using radiobiological models the probabilities for tumor control and normal tissue complications were calculated. For both schedules the tumor control was approximately the same. However, the damage in the normal tissue was larger in conventional fractionated schedule. This is important because patients assistance time to their fractions (15 fractions/25 fractions) can be optimized. Thus, the hypo fractionated schedule has suitable characteristics to be implemented. (Author)

  13. Oxygen as a product of water radiolysis in high-LET tracks. II. Radiobiological implications

    International Nuclear Information System (INIS)

    Consideration is given to the possibility that molecular oxygen generated in the tracks of energetic heavy ions is responsible for the reduction in oxygen enhancement ratio (OER) with increasing linear energy transfer (LET) observed for the loss of reproductive capacity caused by radiation in many cellular organisms. Yields of oxygen relationship of OER to LET for two organisms, Chlamydomonas reinhardii and Shigella flexneri, using a simple diffusion kinetic model for radiobiological action which takes account of the diffusion of oxygen after its formation. The results of these calculations show that the model accounts well for the shape of the OER vs. LET relationship

  14. Experimental radiotherapy and clinical radiobiology. Vol. 18. Proceedings; Experimentelle Strahlentherapie und Klinische Strahlenbiologie. Bd. 18. Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Baumann, Michael; Dahm-Daphi, Jochen; Dikomey, Ekkehard; Petersen, Cordula; Rodemann, H. Peter; Zips, Daniel (eds.)

    2009-07-15

    The proceedings on experimental radiotherapy and clinical radiobiology contain two review articles (prediction of normal tissue reactions after radiotherapy, ?H2AX foci as a marker for DNA double-strand breaks) and 34 contributions to the following topics: Hypoxia and molecular mechanisms of radiation resistance; biological imaging of the tumor micromilieu; DNA repair, genomic instability and carcerogenesis; molecular factors of radiation resistance; actual controversial discussion on possible irradiation caused metastasis risk enhancement; EGFR inhibition and irradiation; biology of experimental radiation/ normal tissue toxicity.

  15. Research and development program, fiscal year 1974

    Energy Technology Data Exchange (ETDEWEB)

    1972-04-01

    The biomedical program of the Laboratory of Nuclear Medicine and Radiation Biology for Fiscal Year 1974 is conducted within the scope of the following categories: Effects of Radiation of Living Organisms; Molecular and Cellular Radiobiology; Land and Fresh Water Environmental Sciences; Radiological and Health Physics and Instrumentation; and Nuclear Medical Research. (ACR)

  16. Investigations on the quality of treatment plans for carbon ion radiotherapy. Beam delivery systems and radiobiological models

    Energy Technology Data Exchange (ETDEWEB)

    Gillmann, Clarissa

    2014-07-01

    In a worldwide effort in research and development, radiation therapy with carbon ions has evolved to a technologically challenging but clinically very promising treatment option for cancer patients. To further improve patient benefit, optimal use of the physical and biological characteristics of carbon ions as well as of the available technologies should be made. The present thesis investigates the impact of different beam delivery systems and radiobiological models on the quality of treatment plans in carbon ion radiotherapy. The results of the study may provide pointers as to the role and the possible future implementation of the different techniques and radiobiological models in existing and upcoming particle therapy centers.

  17. Design of a radiation facility for very small specimens used in radiobiology studies

    International Nuclear Information System (INIS)

    A design of a radiation facility for very small specimens used in radiobiology is presented. This micro-irradiator has been primarily designed to irradiate partial bodies in zebrafish embryos 3-4 mm in length. A miniature x-ray, 50 kV photon beam, is used as a radiation source. The source is inserted in a cylindrical brass collimator that has a pinhole of 1.0 mm in diameter along the central axis to produce a pencil photon beam. The collimator with the source is attached underneath a computer-controlled movable table which holds the specimens. Using a 45 deg. tilted mirror, a digital camera, connected to the computer, takes pictures of the specimen and the pinhole collimator. From the image provided by the camera, the relative distance from the specimen to the pinhole axis is calculated and coordinates are sent to the movable table to properly position the samples in the beam path. Due to its monitoring system, characteristic of the radiation beam, accuracy and precision of specimen positioning, and automatic image-based specimen recognition, this radiation facility is a suitable tool to irradiate partial bodies in zebrafish embryos, cell cultures or any other small specimen used in radiobiology research

  18. Relationship between tumour oxygenation, bioenergetic status and radiobiological hypoxia in an experimental model

    International Nuclear Information System (INIS)

    Tumour oxygenation and bioenergetic status were measured in the same tumour and these results related to radiobiological hypoxia. A C3H mouse mammary carcinoma grown in the feet of CDF1 mice was used. Bioenergetic status was assessed by 31P MRS using a SISCO 7 Tesla magnet, oxygen measurements were done by a polarographic electrode and the hypoxic fraction was determined from direct analysis of the radiation dose-response data. During all examinations restrained, non-anaesthetized mice were allowed to breathe either 100% oxygen, carbogen, normal air, carbon monoxide (CO) at 75, 220, or 660 ppm or had blood flow occluded by clamping. Results showed a significant correlation between the radiobiological hypoxic fraction and % pO2 ≤ 5 mmHg under the different treatment conditions, whereas no correlation was found between beta nucleosidetriphosphate/inorganic phosphate (β-NTP/Pi) ratio and either the hypoxic fraction or the % of pO2 values ≤ 5 mmHg under the different treatment conditions. In conclusion, oxygen electrode measurements were sensitive to changes in tumour hypoxia whereas the bioenergetic status alone seemed to be a less precise measure of hypoxia in this tumour model. Furthermore, the present study demonstrated that tumour cells in vivo can actually maintain the bioenergetic status during a period of severe hypoxia. (orig.)

  19. Bringing the heavy: carbon ion therapy in the radiobiological and clinical context

    International Nuclear Information System (INIS)

    Radiotherapy for the treatment of cancer is undergoing an evolution, shifting to the use of heavier ion species. For a plethora of malignancies, current radiotherapy using photons or protons yields marginal benefits in local control and survival. One hypothesis is that these malignancies have acquired, or are inherently radioresistant to low LET radiation. In the last decade, carbon ion radiotherapy facilities have slowly been constructed in Europe and Asia, demonstrating favorable results for many of the malignancies that do poorly with conventional radiotherapy. However, from a radiobiological perspective, much of how this modality works in overcoming radioresistance, and extending local control and survival are not yet fully understood. In this review, we will explain from a radiobiological perspective how carbon ion radiotherapy can overcome the classical and recently postulated contributors of radioresistance (α/β ratio, hypoxia, cell proliferation, the tumor microenvironment and metabolism, and cancer stem cells). Furthermore, we will make recommendations on the important factors to consider, such as anatomical location, in the future design and implementation of clinical trials. With the existing data available we believe that the expansion of carbon ion facilities into the United States is warranted

  20. The radiobiological principles of boron neutron capture therapy: A critical review

    International Nuclear Information System (INIS)

    The radiobiology of the dose components in a BNCT exposure is examined. The effect of exposure time in determining the biological effectiveness of γ-rays, due to the repair of sublethal damage, has been largely overlooked in the application of BNCT. Recoil protons from fast neutrons vary in their relative biological effectiveness (RBE) as a function of energy and tissue endpoint. Thus the energy spectrum of a beam will influence the RBE of this dose component. Protons from the neutron capture reaction in nitrogen have not been studied but in practice protons from nitrogen capture have been combined with the recoil proton contribution into a total proton dose. The relative biological effectiveness of the products of the neutron capture reaction in boron is derived from two factors, the RBE of the short range particles and the bio-distribution of boron, referred to collectively as the compound biological effectiveness factor. Caution is needed in the application of these factors for different normal tissues and tumors. - Highlights: ► Radiobiological properties of different dose components in BNCT are considered. ► Effectiveness of γ-ray dose depends strongly on exposure time due to sublethal damage repair. ► Effectiveness of fast neutron dose depends on neutron energy spectrum. ► γ-ray and fast neutron characteristics vary between beams and thus weighting factors will differ. ► Weighing factors for boron dose depend on the carrier, the tissue and its mode of administration.

  1. The effect of dose escalation on gastric toxicity when treating lower oesophageal tumours: a radiobiological investigation

    International Nuclear Information System (INIS)

    Using radiobiological modelling to estimate normal tissue toxicity, this study investigates the effects of dose escalation for concurrent chemoradiation therapy (CRT) in lower third oesophageal tumours on the stomach. 10 patients with lower third oesophageal cancer were selected from the SCOPE 1 database (ISCRT47718479) with a mean planning target volume (PTV) of 348 cm3. The original 3D conformal plans (50Gy3D) were compared to newly created RapidArc plans of 50GyRA and 60GyRA, the latter using a simultaneous integrated boost (SIB) technique using a boost volume, PTV2. Dose-volume metrics and estimates of normal tissue complication probability (NTCP) were compared. There was a significant increase in NTCP of the stomach wall when moving from the 50GyRA to the 60GyRA plans (11–17 %, Wilcoxon signed rank test, p = 0.01). There was a strong correlation between the NTCP values of the stomach wall and the volume of the stomach wall/PTV 1 and stomach wall/PTV2 overlap structures (R = 0.80 and R = 0.82 respectively) for the 60GyRA plans. Radiobiological modelling suggests that increasing the prescribed dose to 60Gy may be associated with a significantly increased risk of toxicity to the stomach. It is recommended that stomach toxicity be closely monitored when treating patients with lower third oesophageal tumours with 60Gy

  2. Development of a soft X-ray microprobe for single cell radiobiology

    Institute of Scientific and Technical Information of China (English)

    CHEN Liang; YAN Jingwen; JIANG Shiping; YU Yang

    2009-01-01

    An X-ray microprobe for radiobiological studies was developed which deliver precise doses of radiation to the selected individual cells. The facility used synchrotron radiation as soft X-ray source. A zone plate combining with a pinhole produced a fine probe from bending magnet for single cell irradiating with defined doses. The diameter of microprobe at the target position was about 2 μm by scanning a knife-edge with an AXUV photo diode. The fluxes of soft X-rays at 516.7 eV (2.4 nm) were about 5.4×104 photons/s.100mA measured with the photo diode. The absorbed dose rate for typical yeast cells was about 11.34 Gy/s with the storage current of 100 mA. A preliminary experiment for yeast cells irradiation has shown that the microprobe had a definite biological effect for radiobiological investigations. The soft X-ray microprobe at "water window" region has provided a useful tool for single cell irradiating damage and a capability of individually irradiating a certain numbers of cells each time.

  3. Preliminary results in the application of radiobiological models in the evaluation of radiotherapy plans

    International Nuclear Information System (INIS)

    Notwithstanding the limitations of radiobiological models in the clinical application, its use is becoming more widespread in order to quantitatively assess the bioequivalence of different regimens of irradiation, the effective comparison between different treatment plans by estimating the probability tumor control (TCP) or the probability of normal tissue complication (NTCP), or solve problems, such as the rescheduling of treatments in case of failure. The response to irradiation in the tissues at risk (OARS) depends on factors such as volume irradiated or its organizational structure and behavior can vary for a given dose distribution. Another important aspect is the sensitivity of these models to the variation of parameters (a, a / β, proliferation, clonogenic density, etc.) Measuring the difference between-subjects. Commercial planning systems do not always possible to estimate the biological response of the OARS and CTV. This study presents an assessment of the results of two applications (free ware) and Albireo Target BIOPLAN Cygnus X1 that calculate statistical parameters of the DVH: equivalent uniform dose (EUD), equivalent biological dose (BED), medium dose and other to estimate TCP (Poisson model) and NTCP (Lyman-models-Kutcker Burman and relative seriality) for the calculation of the objective functions: the probability of uncomplicated control (UTCP) based on generalized EUD (f). We studied the response of both systems to the variation of relevant radiobiological parameters and the shape of the DVH. (author)

  4. Heavy-ion radiobiology: new approaches to delineate mechanisms underlying enhanced biological effectiveness.

    Science.gov (United States)

    Blakely, E A; Kronenberg, A

    1998-11-01

    Shortly after the discovery of polonium and radium by Marie Curie and her husband and colleague, Pierre Curie, it was learned that exposure to these alpha-particle emitters produced deleterious biological effects. The mechanisms underlying the increased biological effectiveness of densely ionizing radiations, including alpha particles, neutrons and highly energetic heavy charged particles, remain an active area of investigation. In this paper, we review recent advances in several areas of the radiobiology of these densely ionizing radiations, also known as heavy ions. Advances are described in the areas of DNA damage and repair, chromosome aberrations, mutagenesis, neoplastic transformation in vitro, genomic instability, normal tissue radiobiology and carcinogenesis in vivo. We focus on technical innovations, including novel applications of pulsed-field gel electrophoresis, fluorescence in situ hybridization (FISH), linkage analysis, and studies of gene expression and protein expression. We also highlight the use of new cellular and animal systems, including those with defined DNA repair deficiencies, as well as epithelial cell model systems to assess neoplastic transformation both in vitro and in vivo. The studies reviewed herein have had a substantial impact on our understanding of the genotoxic effects of heavy ions as well as their distinct effects on tissue homeostasis. The use of these radiations in cancer therapy is also discussed. The use of both heavy-ion and proton therapy is on the upswing in several centers around the world, due to their unique energy deposition characteristics that enhance the therapeutic effect and help reduce damage to normal tissue. PMID:9806616

  5. Heavy-ion radiobiology: new approaches to delineate mechanisms underlying enhanced biological effectiveness

    Science.gov (United States)

    Blakely, E. A.; Kronenberg, A.; Chatterjee, A. (Principal Investigator)

    1998-01-01

    Shortly after the discovery of polonium and radium by Marie Curie and her husband and colleague, Pierre Curie, it was learned that exposure to these alpha-particle emitters produced deleterious biological effects. The mechanisms underlying the increased biological effectiveness of densely ionizing radiations, including alpha particles, neutrons and highly energetic heavy charged particles, remain an active area of investigation. In this paper, we review recent advances in several areas of the radiobiology of these densely ionizing radiations, also known as heavy ions. Advances are described in the areas of DNA damage and repair, chromosome aberrations, mutagenesis, neoplastic transformation in vitro, genomic instability, normal tissue radiobiology and carcinogenesis in vivo. We focus on technical innovations, including novel applications of pulsed-field gel electrophoresis, fluorescence in situ hybridization (FISH), linkage analysis, and studies of gene expression and protein expression. We also highlight the use of new cellular and animal systems, including those with defined DNA repair deficiencies, as well as epithelial cell model systems to assess neoplastic transformation both in vitro and in vivo. The studies reviewed herein have had a substantial impact on our understanding of the genotoxic effects of heavy ions as well as their distinct effects on tissue homeostasis. The use of these radiations in cancer therapy is also discussed. The use of both heavy-ion and proton therapy is on the upswing in several centers around the world, due to their unique energy deposition characteristics that enhance the therapeutic effect and help reduce damage to normal tissue.

  6. Radiobiological and PK assays at advance Centre for Training Research and Education in Cancer (ACTREC)

    International Nuclear Information System (INIS)

    Radiobiological, pharmacokinetic and biodistribution studies are of paramount importance for drug development and more so in the development of newer radiation modulators. Radiobiological studies have now graduated from simple cell survival and viability assays to more complex molecular and imaging studies to study radiation modulation both in in-vitro and in-vivo models. Tata Memorial Centre and its research centre (ACTREC) is a premiere cancer centre in India dedicated to cancer research. The Department of Radiation Oncology treats approximately 7000 new patients in a year and is uniquely placed to do both translational radiation and clinical research in the field of drug development. The Clinical Biology Lab of the Department of Radiation Oncology at ACTREC in collaboration with other labs at ACTREC has standardized cell survival assays, DNA damage assays such as Gamma H2AX assay (by flow as well as confocal microscopy), Micronuclei assay and COMET assays using CASP software for quantification. We have also done apoptotic assays. These assays have been conducted for development newer drug formulations (for e.g liposomal radiosensitizers). We also have a strong imaging division having sophisticated microscopes (confocal and single molecule super resolution microscopes) for in-vitro optical imaging and a dedicated preclinical PET/CT/SPECT for in-vivo imaging. The clinical 3T MRI and PET/CT is being used to study the effect of hypoxia in various cancers

  7. Radiobiologically optimized couch shift: A new localization paradigm using cone-beam CT for prostate radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Yimei, E-mail: yhuang2@hfhs.org; Gardner, Stephen J.; Wen, Ning; Zhao, Bo; Gordon, James; Brown, Stephen; Chetty, Indrin J. [Department of Radiation Oncology, Henry Ford Health System, 2799 W Grand Boulevard, Detroit, Michigan 48202 (United States)

    2015-10-15

    Purpose: To present a novel positioning strategy which optimizes radiation delivery by utilizing radiobiological response knowledge and evaluate its use during prostate external beam radiotherapy. Methods: Five patients with low or intermediate risk prostate cancer were evaluated retrospectively in this IRB-approved study. For each patient, a VMAT plan with one 358° arc was generated on the planning CT (PCT) to deliver 78 Gy in 39 fractions. Five representative pretreatment cone beam CTs (CBCT) were selected for each patient. The CBCT images were registered to PCT by a human observer, which consisted of an initial automated registration with three degrees-of-freedom, followed by manual adjustment for agreement at the prostate/rectal wall interface. To determine the optimal treatment position for each CBCT, a search was performed centering on the observer-matched position (OM-position) utilizing a score function based on radiobiological and dosimetric indices (EUD{sub prostate}, D99{sub prostate}, NTCP{sub rectum}, and NTCP{sub bladder}) for the prostate, rectum, and bladder. We termed the optimal treatment position the radiobiologically optimized couch shift position (ROCS-position). Results: The dosimetric indices, averaged over the five patients’ treatment plans, were (mean ± SD) 79.5 ± 0.3 Gy (EUD{sub prostate}), 78.2 ± 0.4 Gy (D99{sub prostate}), 11.1% ± 2.7% (NTCP{sub rectum}), and 46.9% ± 7.6% (NTCP{sub bladder}). The corresponding values from CBCT at the OM-positions were 79.5 ± 0.6 Gy (EUD{sub prostate}), 77.8 ± 0.7 Gy (D99{sub prostate}), 12.1% ± 5.6% (NTCP{sub rectum}), and 51.6% ± 15.2% (NTCP{sub bladder}), respectively. In comparison, from CBCT at the ROCS-positions, the dosimetric indices were 79.5 ± 0.6 Gy (EUD{sub prostate}), 77.3 ± 0.6 Gy (D99{sub prostate}), 8.0% ± 3.3% (NTCP{sub rectum}), and 46.9% ± 15.7% (NTCP{sub bladder}). Excessive NTCP{sub rectum} was observed on Patient 5 (19.5% ± 6.6%) corresponding to localization at OM

  8. Research in radiobiology. Annual report of work in progress in the internal irradiation program

    Energy Technology Data Exchange (ETDEWEB)

    1979-03-31

    The toxicity, retention, biological effects, distribution, decorporation and measuring techniques of radionuclides are discussed. Calculations of trabecular bone formation rates from tetracycline labeling is included. The characteristics of trabecular bone in the Rhesus monkey are discussed. Studies on the early retention and distribution of radium 224 in beagles are included. Studies on the decorporation of plutonium and americium in dogs by DTPA and salicylic acid are presented.

  9. Research in radiobiology. Annual report of work in progress in the internal irradiation program

    International Nuclear Information System (INIS)

    Research progress on studies of the effects of internally deposited radionuclides in dogs, mice, and humans is reported. The studies include toxicity of plutonium 239, radium 226, and radium 224, the kinetics of actinides in beagles, and dosimetry of internal emitters

  10. Research in radiobiology. Annual report of work in progress in the internal irradiation program

    Energy Technology Data Exchange (ETDEWEB)

    Jee, W.S.S.

    1975-03-31

    Separate abstracts were prepared for 15 papers. In addition, twenty-three injection tables are presented for toxicity animals and test animals. The injection tables include the calculated average dose in rads to the skeleton at death for 13 actinides. (HLW)

  11. 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)

    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)

  12. Radiological and Environmental Research Division, Center for Human Radiobiology. Annual report, July 1980-June 1981. [Lead abstract

    Energy Technology Data Exchange (ETDEWEB)

    1982-03-01

    Separate abstracts were prepared for the 22 papers of this annual report of the Center for Human Radiobiology. Abstracts were not written for 2 appendices which contain data on the exposure and radium-induced malignancies of 2259 persons whose radium content has been determined at least once. (KRM)

  13. 77 FR 68155 - The Armed Forces Radiobiology Research Institute TRIGA Reactor: Facility Operating License No. R-84

    Science.gov (United States)

    2012-11-15

    ... NRC's E-Filing rule (72 FR 49139; August 28, 2007). The E-Filing process requires participants to... filing requirements of the NRC's E-Filing Rule (72 FR 49139; August 28, 2007) apply to appeals of NRC... COMMISSION The Armed Forces Radiobiology Research Institute TRIGA Reactor: Facility Operating License No....

  14. Proton Radiobiology

    Energy Technology Data Exchange (ETDEWEB)

    Tommasino, Francesco [GSI Helmholtzzentrum für Schwerionenforschung, Department of Biophysics, Darmstadt 64291 (Germany); Durante, Marco, E-mail: m.durante@gsi.de [GSI Helmholtzzentrum für Schwerionenforschung, Department of Biophysics, Darmstadt 64291 (Germany); Technische Universität Darmstadt, Institut für Festkörperphysik, Darmstadt 64291 (Germany)

    2015-02-12

    In addition to the physical advantages (Bragg peak), the use of charged particles in cancer therapy can be associated with distinct biological effects compared to X-rays. While heavy ions (densely ionizing radiation) are known to have an energy- and charge-dependent increased Relative Biological Effectiveness (RBE), protons should not be very different from sparsely ionizing photons. A slightly increased biological effectiveness is taken into account in proton treatment planning by assuming a fixed RBE of 1.1 for the whole radiation field. However, data emerging from recent studies suggest that, for several end points of clinical relevance, the biological response is differentially modulated by protons compared to photons. In parallel, research in the field of medical physics highlighted how variations in RBE that are currently neglected might actually result in deposition of significant doses in healthy organs. This seems to be relevant in particular for normal tissues in the entrance region and for organs at risk close behind the tumor. All these aspects will be considered and discussed in this review, highlighting how a re-discussion of the role of a variable RBE in proton therapy might be well-timed.

  15. Proton Radiobiology

    Directory of Open Access Journals (Sweden)

    Francesco Tommasino

    2015-02-01

    Full Text Available In addition to the physical advantages (Bragg peak, the use of charged particles in cancer therapy can be associated with distinct biological effects compared to X-rays. While heavy ions (densely ionizing radiation are known to have an energy- and charge-dependent increased Relative Biological Effectiveness (RBE, protons should not be very different from sparsely ionizing photons. A slightly increased biological effectiveness is taken into account in proton treatment planning by assuming a fixed RBE of 1.1 for the whole radiation field. However, data emerging from recent studies suggest that, for several end points of clinical relevance, the biological response is differentially modulated by protons compared to photons. In parallel, research in the field of medical physics highlighted how variations in RBE that are currently neglected might actually result in deposition of significant doses in healthy organs. This seems to be relevant in particular for normal tissues in the entrance region and for organs at risk close behind the tumor. All these aspects will be considered and discussed in this review, highlighting how a re-discussion of the role of a variable RBE in proton therapy might be well-timed.

  16. Proton Radiobiology

    OpenAIRE

    Francesco Tommasino; Marco Durante

    2015-01-01

    In addition to the physical advantages (Bragg peak), the use of charged particles in cancer therapy can be associated with distinct biological effects compared to X-rays. While heavy ions (densely ionizing radiation) are known to have an energy- and charge-dependent increased Relative Biological Effectiveness (RBE), protons should not be very different from sparsely ionizing photons. A slightly increased biological effectiveness is taken into account in proton treatment planning by assuming...

  17. Micro-and nanodosimetry for radiobiological planning in radiotherapy and cancer risk assessment in radiation environment

    International Nuclear Information System (INIS)

    Full text: Microdosimetry and nanodosimetry can provide unique information for prediction of radiobiological properties of radiation, which is important in radiation therapy for accurate dose planning and in radiation protection for cancer induction risk assessment. This demand measurements of the pattern of energies deposited by ionizing radiation on cellular scale and DNA levels.Silicon microelectronics technology is offering a unique opportunity for replacing gas proportional counters (TEPC) with miniature detectors for regional microdosimetry. Silicon on Insulator (SOI) technology has been used for the development of arrays of micron size sensitive volumes for modelling energy deposited in biological cells. The challenge in silicon microdosimetry is the development of well defined sensitive volume (SV) and full charge collection deposited by ionizing radiation in the SV. First generation SOI microdosimeters were developed at CMRP and investigated in a wide range of radiation fields for proton and neutron therapies and recently on isotopic neutron sources and heavy ions with energy up to lGeV/jj,m which are typical for deep space radiation environment. Microdosimetric spectra were obtained in a phantom that are well matched to TEPC and Monte Carlo simulations. Evidence that radiations with the same LET exhibit different biological effects demand development of new sensors sensitive to the track structure of ions or the type of particle for prediction of radiobiological effect of radiation using radiobiological models. New monolithic Si AE-E telescope of cellular size for simultaneous regional microdosimetry and particle identification will be presented and results will be discussed. The new design of the SOI microdosimeter is based on 3D micron and submicron size of Si SVs. This approach allows improvement in the accuracy of the Si microdosimetry because of full charge collection and the ability to measure low LET as low as 0.01 keV/jjm, which is similar to TEPC

  18. Modification of radiobiological effects of 171 MeV protons by elements of physical protection

    Science.gov (United States)

    Bulinina, Taisia; Shurshakov, Vyacheslav; Ivanov, Alexander; Molokanov, Alexander

    2016-07-01

    Space radiation includes protons of various energies. Physical protection is effective in the case of low energy protons (50-100 MeV) and becomes insufficient for radiation with a high part of high-energy protons. In the experiment performed on outbred mice, the purpose of the study was to evaluate the radiobiological effect of 171 MeV protons and protons modified by elements of physical protection of the spacecraft, on a complex of indicators of the functional condition of the system hematopoiesis and the central nervous system in 24 hours after irradiation at 20 cGy dose. The spacecraft radiation protection elements used in the experiment were a construction of wet hygiene wipes called a «protective curtain», and a glass plate imitating an ISS window. Mass thickness of the " protective curtain" in terms of water equivalent was ̴ 6,2 g/cm2. Physical shielding along the path of 171 MeV protons increases their linear energy transfer leading to the absorbed dose elevation and strengthening of the radiobiological effect. In the experiment, the two types of shielding together raised the absorbed dose from 20 to 23.2 cGy. Chemically different materials (glass and water in the wipes) were found to exert unequal modifying effects on physical and biological parameters of the proton-irradiated mice. There was a distinct dose-dependent reduction of bone marrow cellularity within the dose range from 20 cGy to 23.2 cGy in 24 hours after exposure. No modifying effect of the radiation protection elements on spontaneous motor activity was discovered when compared with entrance protons. The group of animals protected by the glass plate exhibited normal orientative-trying reactions and weakened grip with the forelimbs. The effects observed in the experiment indicate the necessity to carry out comprehensive radiobiological researches (physical, biological and mathematical) in assessing the effects of physical protection, that are actual for ensuring radiation safety of crews in

  19. Hadron Radiobiology : Investigation of the Inhibition of ten days Growth of Vicia Faba Roots after Exposure in the 600 MeV Neutron Beam from SC2 Hadron Radiobiology : Investigation of the Inhibition of ten days'Grown of Vicia Faba Roots after Exposure in the 600 MeV Neutron Beam from SC2

    CERN Multimedia

    2002-01-01

    Hadron Radiobiology : Investigation of the Inhibition of ten days Growth of Vicia Faba Roots after Exposure in the 600 MeV Neutron Beam from SC2 Hadron Radiobiology : Investigation of the Inhibition of ten days'Grown of Vicia Faba Roots after Exposure in the 600 MeV Neutron Beam from SC2

  20. Radiobiological studies with the nematode Caenorhabditis elegans. Genetic and developmental effects of high LET radiation

    Science.gov (United States)

    Nelson, G. A.; Schubert, W. W.; Marshall, T. M.

    1992-01-01

    The biological effects of heavy charged particle (HZE) radiation are of particular interest to travellers and planners for long-duration space flights where exposure levels represent a potential health hazard. The unique feature of HZE radiation is the structured pattern of its energy deposition in targets. There are many consequences of this feature to biological endpoints when compared with effects of ionizing photons. Dose vs response and dose-rate kinetics may be modified, DNA and cellular repair systems may be altered in their abilities to cope with damage, and the qualitative features of damage may be unique for different ions. The nematode Caenorhabditis elegans is being used to address these and related questions associated with exposure to radiation. HZE-induced mutation, chromosome aberration, cell inactivation and altered organogenesis are discussed along with plans for radiobiological experiments in space.

  1. Radiobiological studies with the nematode Caenorhabditis elegans. Genetic and developmental effects of high LET radiation

    International Nuclear Information System (INIS)

    The biological effects of heavy charged particle (HZE) radiation are of particular interest to travellers and planners for long-duration space flights where exposure levels represents a potential health hazard. The unique feature of HZE radiation is the structured pattern of its energy deposition in targets. There are many consequences of this feature to biological endpoints when compared with effects of ionizing photons. Dose vs response and dose-rate kinetics may be modified, DNA and cellular repair systems may be altered in their abilities to cope with damage, and the qualitative features of damage may be unique for different ions. The nematode Caenorhabditis elegans is being used to address these and related questions associated with exposure to radiation. HZE-induced mutation, chromosome aberration, cell inactivation and altered organogenesis are discussed along with plans for radiobiological experiments in space. (author)

  2. Radiobiologic risk estimation from dental radiology. Part I. Absorbed doses to critical organs

    International Nuclear Information System (INIS)

    The aim of the present study was to generate one consistent set of data for evaluating and comparing radiobiologic risks from different dental radiographic techniques. To accomplish this goal, absorbed doses were measured in fourteen anatomic sites from (1) five different panoramic machines with the use of rare-earth screens, (2) a twenty-film complete-mouth survey with E-speed film, long round cone, (3) a twenty-film complete-mouth survey with E-speed film, long rectangular cone, (4) a four-film interproximal survey with E-speed film, long round cone, and (5) a four-film interproximal survey with E-speed film, long rectangular cone. The dose to the thyroid gland, the active bone marrow, the brain, and the salivary glands was evaluated by means of exposure of a tissue-equivalent phantom, fitted with lithium fluoride thermoluminescent dosimeters (TLDs) at the relevant locations

  3. Radiobiologic risk estimation from dental radiology. Part II. Cancer incidence and fatality

    International Nuclear Information System (INIS)

    With the use of the measured absorbed doses from part I of this article, the specific radiobiologic risk to the patient from (1) five different panoramic machines with rare-earth screens, (2) a 20-film complete-mouth survey with E-speed film, long round cone, (3) a 20-film complete-mouth survey with E-speed film, long rectangular cone, (4) a 4-film interproximal survey with E-speed film, long round cone, and (5) a 4-film interproximal survey with E-speed film, long rectangular cone, was calculated. The estimated risks are expressed in two ways: the probability of radiation-induced cancer in specific organs per million examinations and the probability of expression of a fatal cancer per million examinations. The highest risks calculated were from the complete-mouth survey with the use of round collimation. The lowest risks calculated were from panoramic radiography and four interproximal radiographs with rectangular collimation

  4. Treatment plan comparison between helical tomotherapy and MLC-based IMRT using radiobiological measures

    Science.gov (United States)

    Mavroidis, Panayiotis; Costa Ferreira, Brigida; Shi, Chengyu; Lind, Bengt K.; Papanikolaou, Nikos

    2007-07-01

    The rapid implementation of advanced treatment planning and delivery technologies for radiation therapy has brought new challenges in evaluating the most effective treatment modality. Intensity-modulated radiotherapy (IMRT) using multi-leaf collimators (MLC) and helical tomotherapy (HT) are becoming popular modes of treatment delivery and their application and effectiveness continues to be investigated. Presently, there are several treatment planning systems (TPS) that can generate and optimize IMRT plans based on user-defined objective functions for the internal target volume (ITV) and organs at risk (OAR). However, the radiobiological parameters of the different tumours and normal tissues are typically not taken into account during dose prescription and optimization of a treatment plan or during plan evaluation. The suitability of a treatment plan is typically decided based on dosimetric criteria such as dose-volume histograms (DVH), maximum, minimum, mean and standard deviation of the dose distribution. For a more comprehensive treatment plan evaluation, the biologically effective uniform dose ({\\bar{\\bar{D}}}) is applied together with the complication-free tumour control probability (P+). Its utilization is demonstrated using three clinical cases that were planned with two different forms of IMRT. In this study, three different cancer types at different anatomical sites were investigated: head and neck, lung and prostate cancers. For each cancer type, a linac MLC-based step-and-shoot IMRT plan and a HT plan were developed. The MLC-based IMRT treatment plans were developed on the Philips treatment-planning platform, using the Pinnacle 7.6 software release. For the tomotherapy HiArt plans, the dedicated tomotherapy treatment planning station was used, running version 2.1.2. By using {\\bar{\\bar{D}}} as the common prescription point of the treatment plans and plotting the tissue response probabilities versus {\\bar{\\bar{D}}} for a range of prescription doses

  5. A method for radiobiological investigations in radiation fields with different LET and high dose rates

    International Nuclear Information System (INIS)

    For investigations: 1. Performed in the field of radiobiology with different LET-radiation and a relatively high background dose rate of one component (e.g. investigations with fast and intermediate reactor neutrons) 2. Concerning radiation risk studies within a wide range 3. Of irradiations, covering a long time period (up to 100 days) a test system is necessary which on the one hand makes it possible to analyze the influence of different LET radiation and secondly shows a relative radiation resistant behaviour and allows a simple cell cycle regulation. A survey is given upon the installed device of a simple cell observation method, the biological test system used and the analysis of effects caused by dose, repair and LET. It is possible to analyze the behaviour of the nonsurvival cells and to demonstrate different reactions of the test parameters to the radiation of different LET. (author)

  6. Heavy charged particle radiobiology: using enhanced biological effectiveness and improved beam focusing to advance cancer therapy.

    Science.gov (United States)

    Allen, Christopher; Borak, Thomas B; Tsujii, Hirohiko; Nickoloff, Jac A

    2011-06-01

    Ionizing radiation causes many types of DNA damage, including base damage and single- and double-strand breaks. Photons, including X-rays and γ-rays, are the most widely used type of ionizing radiation in radiobiology experiments, and in radiation cancer therapy. Charged particles, including protons and carbon ions, are seeing increased use as an alternative therapeutic modality. Although the facilities needed to produce high energy charged particle beams are more costly than photon facilities, particle therapy has shown improved cancer survival rates, reflecting more highly focused dose distributions and more severe DNA damage to tumor cells. Despite early successes of charged particle radiotherapy, there is room for further improvement, and much remains to be learned about normal and cancer cell responses to charged particle radiation. PMID:21376738

  7. AFRRI (Armed Forces Radiobiology Research Institute) reports, April-June 1985. Technical report

    Energy Technology Data Exchange (ETDEWEB)

    1985-01-01

    The following titles are included in this collection of reprints: Presence of a high-affinity Ca(s+) - and Mg(2+) - dependent ATPase in rat peritoneal mast-cell membranes; Prostanoid production by lipopolysaccharide stimulated Kupffer cells; Antihistamines block radiation-induced increased intestinal blood flow in canines; WR-2721 inhibition of radiation-induced prostaglandin excretion in rats; Effects of mixed neutron-gamma total-body irradiation on physical activity performance of rhesus monkeys; Immunologic and hematologic perturbations in models of combined injury; Hematopoiesis in conventional mice after wound trauma; Carrier generation recombination, and transport in organic crystals; Energy transfer and molecular weight effects on polymer luminescence. Keywords: Radiobiology; Military research.

  8. Hypo-fractionated treatment in radiotherapy: radio-biological models Tcp and NTCP

    International Nuclear Information System (INIS)

    At the present time the breast cancer in Mexico has the first place of incidence of the malignant neoplasia s in the women, and represents 11.34% of all the cancer cases. On the other hand, the treatments for cancer by means of ionizing radiations have been dominated under the approaches of the medical radio-oncologists which have been based on test and error by many years. The radio-biological models, as the Tcp, NTCP and dosimetric variables, for their clinical application in the conventional radiotherapy with hypo-fractionation have as purpose predicting personalized treatment plans that they present most probability of tumor control and minor probability of late reactions, becoming this way support tools in the decisions taking for the patient treatments planning of Medical Physicists and Radio-oncologists. (Author)

  9. Water versus DNA: new insights into proton track-structure modelling in radiobiology and radiotherapy

    Science.gov (United States)

    Champion, C.; Quinto, M. A.; Monti, J. M.; Galassi, M. E.; Weck, P. F.; Fojón, O. A.; Hanssen, J.; Rivarola, R. D.

    2015-10-01

    Water is a common surrogate of DNA for modelling the charged particle-induced ionizing processes in living tissue exposed to radiations. The present study aims at scrutinizing the validity of this approximation and then revealing new insights into proton-induced energy transfers by a comparative analysis between water and realistic biological medium. In this context, a self-consistent quantum mechanical modelling of the ionization and electron capture processes is reported within the continuum distorted wave-eikonal initial state framework for both isolated water molecules and DNA components impacted by proton beams. Their respective probability of occurrence—expressed in terms of total cross sections—as well as their energetic signature (potential and kinetic) are assessed in order to clearly emphasize the differences existing between realistic building blocks of living matter and the controverted water-medium surrogate. Consequences in radiobiology and radiotherapy will be discussed in particular in view of treatment planning refinement aiming at better radiotherapy strategies.

  10. Linear versus non-linear: a perspective from health physics and radiobiology

    International Nuclear Information System (INIS)

    There is a vigorous debate about whether or not there may be a 'threshold' for radiation-induced adverse health effects. A linear-no threshold (LNT) model allows radiation protection practitioners to manage putative risk consistently, because different types of exposure, exposures at different times, and exposures to different organs may be summed. If we are to argue to regulators and the public that low doses are less dangerous than we presently assume, it is incumbent on us to prove this. The question is, therefore, whether any consonant body of evidence exists that the risk of low doses has been over-estimated. From the perspectives of both health physics and radiobiology, we conclude that the evidence for linearity at high doses (and arguably of fairly small total doses if delivered at high dose rate) is strong. For low doses (or in fact, even for fairly high doses) delivered at low dose rate, the evidence is much less compelling. Since statistical limitations at low doses are almost always going to prevent a definitive answer, one way or the other, from human data, we need a way out of this epistemological dilemma of 'LNT or not LNT, that is the question'. To our minds, the path forward is to exploit (1) radiobiological studies which address directly the question of what the dose and dose rate effectiveness factor is in actual human bodies exposed to low-level radiation, in concert with (2) epidemiological studies of human populations exposed to fairly high doses (to obtain statistical power) but where exposure was protracted over some years. (author)

  11. Radioembolisation with 90Y-microspheres: dosimetric and radiobiological investigation for multi-cycle treatment

    International Nuclear Information System (INIS)

    Radioembolisation with 90Y-microspheres is a new locoregional treatment of hepatic lesions, usually applied as single cycle. Multi-cycle treatments might be considered as a strategy to improve the risk-benefit balance. With the aim to derive suitable information for patient tailored therapy, available patients' dosimetric data were reviewed according to the linear-quadratic model and converted into biological effective dose (BED) values. Single vs. multi-cycle approaches were compared through radiobiological perspective. Twenty patients with metastatic lesions underwent radioembolisation. The 90Y-administered activity (AA) was established in order to respect a precautionary limit dose (40 Gy) for the non-tumoral liver (NTL). BED was calculated setting α/β 2.5 Gy (NTL), 10 Gy (tumours); T1/2,eff = T1/2,phys = 64.2 h; T1/2,rep = 2.5 h (NTL), 1.5 h (tumours). The BED to NTL was considered as a constraint for multi-cycle approach. The AA for two cycles and the percent variations of AA, tumour dose, BED were estimated. In one-cycle, for a prescribed BED to NTL of 64 Gy (NTL dose = 40 Gy), AA was 1.7 (0.9-3.2) GBq, tumour dose was 130 (65-235) Gy, and tumour BED was 170 (75-360) Gy. Considering two cycles, ∝15% increase was found for AA and dose to NTL, with unvaried BED for NTL. Tumour dose increase was 20 (10-35) Gy; tumour BED increase was 10 (3-11) Gy. In different protocols allowing 80 Gy to NTL, the BED sparing estimated was ∝50 Gy (two cycles) and 65 Gy (three cycles). From a radiobiological perspective, multi-cycle treatments would allow administering higher activities with increased tumour irradiation and preserved radiation effects on NTL. Trials comparing single vs. multiple cycles are suggested. (orig.)

  12. Direct relationship between radiobiological hypoxia in tumors and monoclonal antibody detection of EF5 cellular adducts.

    Science.gov (United States)

    Lee, J; Siemann, D W; Koch, C J; Lord, E M

    1996-07-29

    While the potential importance of hypoxia in limiting the sensitivity of tumor cells to ionizing radiation has long been appreciated, methods for accurately quantifying the number of radiation-resistant hypoxic cells within tumors have been lacking. We have used the pentafluorinated derivative [2-(2-nitro-1H-imidazol-1-yl)-N-(2,2,3,3,3-pentafluoropropyl)-acet amide] of etanidazole (EF5), which binds selectively to hypoxic cells. The adducts formed between EF5 and cellular proteins in the hypoxic cells were detected using the specific monoclonal antibody (MAb), ELK3-51 conjugated to the flurochrome Cy3, and the number of hypoxic cells was quantified by flow cytometry. To verify the validity of this technique for the detection of hypoxic cells, mice bearing KHT sarcomas were treated with various agents to alter tumor oxygenation and hence vary the fraction of radiobiologically hypoxic tumor cells. The percentage of EF5 binding cells was then compared directly with the clonogenic survival of the tumor cells following radiation treatment under the various pretreatment conditions. The results showed that allowing the mice to breathe carbogen (5% CO2/95% O2) prior to irradiation reduced clonogenic cell survival approx. 6-fold and led to an absence of cells binding high levels of EF5. In contrast, pretreating the tumor-bearing animals with either hydralazine, which decreased tumor blood flow, or phenylhydrazine hydrochloride, which made the mice anemic, increased tumor cell survival following irradiation 2- to 4-fold, indicative of an increase in the fraction of hypoxic tumor cells. EF5 measurements made under identical conditions illustrated a shift in the cells in the tumor to high EF5 binding. Our results demonstrate that flow cytometric measurement by fluorescent MAb binding to EF5 adducts may relate directly to radiobiological hypoxia in KHT tumors measured by conventional methods. PMID:8707411

  13. Is there a role for comparative radiobiology in the development of a policy to protect the environment from the effects of ionizing radiation? Comparative radiobiology and radiation protection

    International Nuclear Information System (INIS)

    The last few years has seen what people are now referring to as a 'shifting paradigm' in our way of thinking about radiation effects on biological systems. The concept of the central role of DNA damage due to double strand breaks induced by a radiation 'hit' has been itself hit by many studies showing persistent effects in the distant progeny of radiation exposed cells. This phenomenon is known as radiation induced genomic instability. More recently evidence has been accumulating that not even the parent cell need be exposed to radiation (the bystander effect), and that the bystander cells can demonstrate genomic instability and effects at low doses which are inconsistent with a mechanism based on DNA hits as important targets at low doses. The new paradigm suggests that cellular stress responses or damage signalling through a range of signal transduction pathways are involved. Cell-cell contact or secretion of damage signalling molecules can induce responses in undamaged and unirradiated cells. Are these new effects relevant to risk assessment, or does it matter how radiation affects cells if we have good epidemiological evidence on which to base our risk estimates? If DNA based dose responses are not so important at environmentally relevant doses, then it is not logical to base our environmental protection system on consideration of radiation dose as if this is in some way unique and not affected by the presence of other environmental stressors. The aim of this paper is to review the new concepts and to consider reasons why they might alter our methods of risk estimation. In particular the paper considers the impact of the new concepts on environmental protection and discusses the need for research in the field of comparative radiobiology if we are to develop policies which can adequately protect biodiversity. (author)

  14. Estimation of the radiobiological and kinetic factors of radiosensitivity and radiocurability of metastases of squamous cell carcinoma of the larynx to neck lymph nodes

    International Nuclear Information System (INIS)

    The usefulness of theoretical model of tumour growth and experimental methods of kinetic and radiobiological factors for analysis of clinical data to improve the effectiveness of dose fractionation are checked. 176 refs., 27 figs., 19 tabs. (author)

  15. Optimization in brachytherapy with the implementation of Radiobiology; Optimizacion en Braquiterapia con la implementacion de la Radiobiologia

    Energy Technology Data Exchange (ETDEWEB)

    Duran, M.P.; Bourel, V.J.; Rodriguez, I.; Torre, M. de la; Caneva, S. [Braqui S.R.L. Viamonte 1861, Buenos Aires (Argentina)

    1998-12-31

    In the brachytherapy planning treatments with High dose rates (HDR), the optimization algorithms used are based in dosimetric considerations and/or geometric ones, ignoring the radiobiological response of the tissue treated. In this work we wish to show the implementation of radiobiological concepts in the optimization. Assuming that the subtiles differences that result in the dose distribution among the different optimization models which are not visible in an isodose plane, it is studied how is classically make it , the quality implant through natural histograms about dose volumes and the resulting parameters. Also is studied the necrosis probability which may be caused by the choice of some optimization model, allowing with this the choice of the best implant. (Author)

  16. Radiation-induced cardiac damage in early left breast cancer patients: Risk factors, biological mechanisms, radiobiology, and dosimetric constraints

    International Nuclear Information System (INIS)

    Today there is general awareness of the potential damage to the heart in left-sided (more than in right-sided) breast cancer radiotherapy (RT). Historical changes in tumor and heart doses are presented here along with the impact of different RT techniques and volumes. Individual and pharmacological risk factors are also examined with respect to radiation damage. The biological mechanisms of harm are only partially understood, such as the radiobiology of heart damage due to the presence of various radiosensitive structures and their topographic heterogeneity. Furthermore, individual variability may expose patients to higher or lower risks of late cardiac damage or death. Damage mechanisms and radiobiological characteristics in heart irradiation are presented in relation to dosimetric and biological parameters.

  17. Radiobiological effects in organisms of plants and animals exposed to ionizing irradiation in the Chernobyl NPP zone

    International Nuclear Information System (INIS)

    Influence of ionizing radiation on forest ecosystems most clearly revealed itself near the Chernobyl NPP (ChNPP), were magnitudes of absorbed doses reached 'lethal' values, as applied to conifers. Main contribution to absorbed dose was due to beta-radiation of short-living radionuclides. To largest extent the radiobiological effects appeared at injured plantations of pines and firs. Nevertheless, during the first year maximum absorbed doses influenced also on leaf-bearing trees (birch, alder, asp) which then rehabilitated themselves completely

  18. Relationships Between Rectal Wall Dose-Volume Constraints and Radiobiologic Indices of Toxicity for Patients With Prostate Cancer

    International Nuclear Information System (INIS)

    Purpose: The purpose of this article was to investigate how exceeding specified rectal wall dose-volume constraints impacts on the risk of late rectal bleeding by using radiobiologic calculations. Methods and Materials: Dose-volume histograms (DVH) of the rectal wall of 250 patients with prostate cancer were analyzed. All patients were treated by three-dimensional conformal radiation therapy, receiving mean target doses of 80 Gy. To study the main features of the patient population, the average and the standard deviation of the distribution of DVHs were generated. The mean dose , generalized equivalent uniform dose formulation (gEUD), modified equivalent uniform dose formulation (mEUD)0, and normal tissue complication probability (NTCP) distributions were also produced. The DVHs set was then binned into eight classes on the basis of the exceeding or the fulfilling of three dose-volume constraints: V40 = 60%, V50 = 50%, and V70 = 25%. Comparisons were made between them by , gEUD, mEUD0, and NTCP. Results: The radiobiologic calculations suggest that late rectal toxicity is mostly influenced by V70. The gEUD and mEUD0 are risk factors of toxicity always concordant with NTCP, inside each DVH class. The mean dose, although a reliable index, may be misleading in critical situations. Conclusions: Both in three-dimensional conformal radiation therapy and particularly in intensity-modulated radiation therapy, it should be known what the relative importance of each specified dose-volume constraint is for each organ at risk. This requires a greater awareness of radiobiologic properties of tissues and radiobiologic indices may help to gradually become aware of this issue

  19. Realization of radiobiological in vitro cell experiments at conventional X-ray tubes and unconventional radiation sources

    OpenAIRE

    Beyreuther, Elke

    2010-01-01

    More than hundred years after the discovery of X-rays different kinds of ionizing radiation are ubiquitous in medicine, applied to clinical diagnostics and cancer treatment as well. Irrespective of their nature, the widespread application of radiation implies its precise dosimetric characterization and detailed knowledge of the radiobiological effects induced in cancerous and normal tissue. Starting with in vitro cell irradiation experiments, which define basic parameters for the subsequent t...

  20. DEGRO practical guidelines for radiotherapy of non-malignant disorders. Part I: physical principles, radiobiological mechanisms, and radiogenic risk

    International Nuclear Information System (INIS)

    Synopsis of the introductory paragraph of the DEGRO consensus S2e-guideline recommendations for the radiotherapy of benign disorders, including physical principles, radiobiological mechanisms, and radiogenic risk. This work is based on the S2e-guideline recommendations published November 14, 2013. The basic principles of radiation physics and treatment delivery, evaluation of putative underlying radiobiological mechanisms, and the assessment of genetic and cancer risk following low-dose irradiation will be presented. Radiation therapy of benign diseases is performed according to similar physical principles as those governing treatment of malignant diseases in radiation oncology, using the same techniques and workflows. These methods comprise usage of orthovoltage X-ray units, gamma irradiation facilities, linear accelerators (LINACs), and brachytherapy. Experimental in vitro and in vivo models recently confirmed the clinically observed anti-inflammatory effect of low-dose X-irradiation, and implicated a multitude of radiobiological mechanisms. These include modulation of different immunological pathways, as well as the activities of endothelial cells, mono- and polymorphonuclear leukocytes, and macrophages. The use of effective dose for radiogenic risk assessment and the corresponding tumor incidence rate of 5.5 %/Sv are currently controversially discussed. Some authors argue that the risk of radiation-induced cancers should be estimated on the basis of epidemiological data. However, such data are rarely available at present and associated with high variability. Current radiobiological studies clearly demonstrate a therapeutic effectiveness of radiation therapy used to treat benign diseases and implicate various molecular mechanisms. Radiogenic risks should be taken into account when applying radiation treatment for benign diseases. (orig.)

  1. A study of the radiobiological modeling of the conformal radiation therapy in cancer treatment

    Science.gov (United States)

    Pyakuryal, Anil Prasad

    Cancer is one of the leading causes of mortalities in the world. The precise diagnosis of the disease helps the patients to select the appropriate modality of the treatments such as surgery, chemotherapy and radiation therapy. The physics of X-radiation and the advanced imaging technologies such as positron emission tomography (PET) and computed tomography (CT) plays an important role in the efficient diagnosis and therapeutic treatments in cancer. However, the accuracy of the measurements of the metabolic target volumes (MTVs) in the PET/CT dual-imaging modality is always limited. Similarly the external beam radiation therapy (XRT) such as 3D conformal radiotherapy (3DCRT) and intensity modulated radiation therapy (IMRT) is the most common modality in the radiotherapy treatment. These treatments are simulated and evaluated using the XRT plans and the standard methodologies in the commercial planning system. However, the normal organs are always susceptible to the radiation toxicity in these treatments due to lack of knowledge of the appropriate radiobiological models to estimate the clinical outcomes. We explored several methodologies to estimate MTVs by reviewing various techniques of the target volume delineation using the static phantoms in the PET scans. The review suggests that the more precise and practical method of delineating PET MTV should be an intermediate volume between the volume coverage for the standardized uptake value (SUV; 2.5) of glucose and the 50% (40%) threshold of the maximum SUV for the smaller (larger) volume delineations in the radiotherapy applications. Similarly various types of optimal XRT plans were designed using the CT and PET/CT scans for the treatment of various types of cancer patients. The qualities of these plans were assessed using the universal plan-indices. The dose-volume criteria were also examined in the targets and organs by analyzing the conventional dose-volume histograms (DVHs). The biological models such as tumor

  2. Studies of SSNTDs made from LR-115 in view of their applicability in radiobiological experiments with alpha particles

    Energy Technology Data Exchange (ETDEWEB)

    Doerschel, B. E-mail: doerschel@physik.tu-dresden.de; Hermsdorf, D.; Pieck, S.; Starke, S.; Thiele, H.; Weickert, F

    2003-06-01

    Radiobiological studies on cell monolayers irradiated by charged particles need to determine the number and position of particle traversals. Solid state nuclear track detectors used as basic substrate for the cell layers are in principle suitable for this purpose. The detector foils must be as thin as possible but still guaranteeing mechanical stability. Two types of LR-115, red coloured and colourless, were tested in the present work. The studies aimed at optimisation of the etching conditions and determination of the registration efficiency for alpha particles in a wide range of energies and angles of incidence. Specific requirements have to be fulfilled for application of the detector foils under the environmental conditions of radiobiological experiments. Most important are biocompatibility between detector and cells and registration properties insensible against special treatments, as UV sterilisation and cell plating prior to irradiation as well as cell incubation after the irradiation. The experimental studies performed with alpha particles showed that environmental conditions of radiobiological experiments do not change the registration properties of LR-115 detectors significantly.

  3. WE-E-BRE-04: Dual Focal Spot Dose Painting for Precision Preclinical Radiobiological Investigations

    Energy Technology Data Exchange (ETDEWEB)

    Stewart, J; Lindsay, P [Princess Margaret Cancer Centre, Toronto (Canada); University of Toronto, Toronto (Canada); Jaffray, D [Princess Margaret Cancer Centre, Toronto (Canada); The Techna Institute for the Advancement of Technology for Health, Toronto (Canada)

    2014-06-15

    Purpose: Recent progress in small animal radiotherapy systems has provided the foundation for delivering the heterogeneous, millimeter scale dose distributions demanded by preclinical radiobiology investigations. Despite advances in preclinical dose planning, delivery of highly heterogeneous dose distributions is constrained by the fixed collimation systems and large x-ray focal spot common in small animal radiotherapy systems. This work proposes a dual focal spot dose optimization and delivery method with a large x-ray focal spot used to deliver homogeneous dose regions and a small focal spot to paint spatially heterogeneous dose regions. Methods: Two-dimensional dose kernels were measured for a 1 mm circular collimator with radiochromic film at 10 mm depth in a solid water phantom for the small and large x-ray focal spots on a recently developed small animal microirradiator. These kernels were used in an optimization framework which segmented a desired dose distribution into low- and high-spatial frequency regions for delivery by the large and small focal spot, respectively. For each region, the method determined an optimal set of stage positions and beam-on times. The method was demonstrated by optimizing a bullseye pattern consisting of 0.75 mm radius circular target and 0.5 and 1.0 mm wide rings alternating between 0 and 2 Gy. Results: Compared to a large focal spot technique, the dual focal spot technique improved the optimized dose distribution: 69.2% of the optimized dose was within 0.5 Gy of the intended dose for the large focal spot, compared to 80.6% for the dual focal spot method. The dual focal spot design required 14.0 minutes of optimization, and will require 178.3 minutes for automated delivery. Conclusion: The dual focal spot optimization and delivery framework is a novel option for delivering conformal and heterogeneous dose distributions at the preclinical level and provides a new experimental option for unique radiobiological investigations

  4. Radioembolisation with {sup 90}Y-microspheres: dosimetric and radiobiological investigation for multi-cycle treatment

    Energy Technology Data Exchange (ETDEWEB)

    Cremonesi, Marta; Ferrari, Mahila; Pedroli, Guido [European Institute of Oncology, Unit of Medical Physics, Milan (Italy); Bartolomei, Mirco; Arico, Demetrio; De Cicco, Concetta [European Institute of Oncology, Division of Nuclear Medicine, Milan (Italy); Orsi, Franco; Bonomo, Guido [European Institute of Oncology, Unit of Interventistic Radiology, Milan (Italy); Mallia, Andrew [Gamma Unit, Radiology Department, St. Luke' s Hospital (Malta); Paganelli, Giovanni [European Institute of Oncology, Division of Nuclear Medicine, Milan (Italy)

    2008-11-15

    Radioembolisation with {sup 90}Y-microspheres is a new locoregional treatment of hepatic lesions, usually applied as single cycle. Multi-cycle treatments might be considered as a strategy to improve the risk-benefit balance. With the aim to derive suitable information for patient tailored therapy, available patients' dosimetric data were reviewed according to the linear-quadratic model and converted into biological effective dose (BED) values. Single vs. multi-cycle approaches were compared through radiobiological perspective. Twenty patients with metastatic lesions underwent radioembolisation. The {sup 90}Y-administered activity (AA) was established in order to respect a precautionary limit dose (40 Gy) for the non-tumoral liver (NTL). BED was calculated setting {alpha}/{beta} = 2.5 Gy (NTL), 10 Gy (tumours); T{sub 1/2,eff} = T{sub 1/2,phys} = 64.2 h; T{sub 1/2,rep} = 2.5 h (NTL), 1.5 h (tumours). The BED to NTL was considered as a constraint for multi-cycle approach. The AA for two cycles and the percent variations of AA, tumour dose, BED were estimated. In one-cycle, for a prescribed BED to NTL of 64 Gy (NTL dose = 40 Gy), AA was 1.7 (0.9-3.2) GBq, tumour dose was 130 (65-235) Gy, and tumour BED was 170 (75-360) Gy. Considering two cycles, {proportional_to}15% increase was found for AA and dose to NTL, with unvaried BED for NTL. Tumour dose increase was 20 (10-35) Gy; tumour BED increase was 10 (3-11) Gy. In different protocols allowing 80 Gy to NTL, the BED sparing estimated was {proportional_to}50 Gy (two cycles) and 65 Gy (three cycles). From a radiobiological perspective, multi-cycle treatments would allow administering higher activities with increased tumour irradiation and preserved radiation effects on NTL. Trials comparing single vs. multiple cycles are suggested. (orig.)

  5. Collimator design for spatially-fractionated proton beams for radiobiology research

    Science.gov (United States)

    Lee, Eunsin; Meyer, Juergen; Sandison, George

    2016-07-01

    Preclinical and translational research is an imperative to improve the efficacy of proton radiotherapy. We present a feasible and practical method to produce spatially-modulated proton beams for cellular and small animal research for clinical and research facilities. The University of Washington (UW) 50.5 MeV proton research beamline hosting a brass collimation system was modeled using Monte Carlo simulations. This collimator consisted of an array of 2 cm long slits to cover an area of 2  ×  2 cm2. To evaluate the collimator design effects on dose rate, valley dose and the peak-to-valley dose ratios (PVDR) the following parameters were varied; slit width (0.1–1.0 mm), peak center-to-center distance (1–3 mm), collimator thickness (1–7 cm) and collimator location along the beam axis. Several combinations of slit widths and 1 mm spacing achieved uniform dose at the Bragg peak while maintaining spatial modulation on the beam entrance. A more detailed analysis was carried out for the case of a slit width of 0.3 mm, peak center-to-center distance of 1 mm, a collimator thickness of 5 cm and with the collimator flush against the water phantom. The dose rate at 5 mm depth dropped relative to an open field by a factor of 12 and produced a PVDR of 10.1. Technical realization of proton mini-beams for radiobiology small animal research is demonstrated to be feasible. It is possible to obtain uniform dose at depth while maintaining reasonable modulation at shallower depths near the beam entrance. While collimator design is important the collimator location has a strong influence on the entrance region PVDRs and on dose rate. These findings are being used to manufacture a collimator for installation on the UW cyclotron proton beam nozzle. This collimator will enable comparative studies on the radiobiological efficacy of x-rays and proton beams.

  6. An in vitro study of the radiobiological effects of flattening filter free radiotherapy treatments

    International Nuclear Information System (INIS)

    Flattening filter free (FFF) linear accelerators allow for an increase in instantaneous dose-rate of the x-ray pulses by a factor of 2–6 over the conventional flattened output. As a result, radiobiological investigations are being carried out to determine the effect of these higher dose-rates on cell response. The studies reported thus far have presented conflicting results, highlighting the need for further investigation. To determine the radiobiological impact of the increased dose-rates from FFF exposures a Varian Truebeam medical linear accelerator was used to irradiate two human cancer cell lines in vitro, DU-145 prostate and H460 non-small cell lung, with both flattened and FFF 6 MV beams. The fluence profile of the FFF beam was modified using a custom-designed Nylon compensator to produce a similar dose profile to the flattened beam (6X) at the cell surface but at a higher instantaneous dose-rate. For both cell lines there appeared to be no significant change in cell survival. Curve fitting coefficients for DU145 cells irradiated with constant average dose-rates were 6X: α = 0.09 ± 0.03, β = 0.03 ± 0.01 and 6FFF: α = 0.14 ± 0.13, β = 0.03 ± 0.02 with a significance of p = 0.75. For H460 cells irradiated with the same instantaneous dose-rate but different average dose-rate the fit coefficients were 6FFF (low dose-rate): α = 0.21 ± 0.11, 0.07 ± 0.02 and 6FFF (high dose-rate): α = 0.21 ± 0.16, 0.07 ± 0.03, with p = 0.79. The results indicate that collective damage behaviour does not occur at the instantaneous dose-rates investigated here and that the use of either modality should result in the same clinical outcome, however this will require further validation in vivo. (note)

  7. An in vitro study of the radiobiological effects of flattening filter free radiotherapy treatments

    Science.gov (United States)

    King, R. B.; Hyland, W. B.; Cole, A. J.; Butterworth, K. T.; McMahon, S. J.; Redmond, K. M.; Trainer, C.; Prise, K. M.; McGarry, C. K.; Hounsell, A. R.

    2013-03-01

    Flattening filter free (FFF) linear accelerators allow for an increase in instantaneous dose-rate of the x-ray pulses by a factor of 2-6 over the conventional flattened output. As a result, radiobiological investigations are being carried out to determine the effect of these higher dose-rates on cell response. The studies reported thus far have presented conflicting results, highlighting the need for further investigation. To determine the radiobiological impact of the increased dose-rates from FFF exposures a Varian Truebeam medical linear accelerator was used to irradiate two human cancer cell lines in vitro, DU-145 prostate and H460 non-small cell lung, with both flattened and FFF 6 MV beams. The fluence profile of the FFF beam was modified using a custom-designed Nylon compensator to produce a similar dose profile to the flattened beam (6X) at the cell surface but at a higher instantaneous dose-rate. For both cell lines there appeared to be no significant change in cell survival. Curve fitting coefficients for DU145 cells irradiated with constant average dose-rates were 6X: α = 0.09 ± 0.03, β = 0.03 ± 0.01 and 6FFF: α = 0.14 ± 0.13, β = 0.03 ± 0.02 with a significance of p = 0.75. For H460 cells irradiated with the same instantaneous dose-rate but different average dose-rate the fit coefficients were 6FFF (low dose-rate): α = 0.21 ± 0.11, 0.07 ± 0.02 and 6FFF (high dose-rate): α = 0.21 ± 0.16, 0.07 ± 0.03, with p = 0.79. The results indicate that collective damage behaviour does not occur at the instantaneous dose-rates investigated here and that the use of either modality should result in the same clinical outcome, however this will require further validation in vivo.

  8. What is the role of radiation in the treatment of subfoveal membranes: Review of radiobiologic, pathologic, and other considerations to initiate a multimodality discussion

    International Nuclear Information System (INIS)

    Background: Single-dose-fraction conformal proton beam and multiple-fraction X ray dose schedules have been used to treat subfoveal neovascular membranes. All schedules successfully controlled membrane progression, stabilized vision in most patients, and increased visual acuity in some. Conformal protons also decreased the radiation dose to healthy tissues outside the designated volume (16 mm in diameter). It appears that radiation therapy could be useful and cost-effective, but neither the optimal time-dose schedule single or multiple dose fractions nor the type of radiation proton conformal beam or x-ray therapy are defined. Methods: By means of an extensive literature survey, we reviewed the rationale for using radiation to treat subfoveal neovascularization, examined a paradigm of radiation interaction with tissue, reviewed the histopathology of neovascular membranes, and documented the role of growth factors in the pathophysiology of the disease. Accepting that the eye is an extracranial brain extension, and that its microvasculature has properties similar to brain microvessels, we reviewed the radiobiologic response of brain microvessels. We also revisited the controversy concerning the efficacy of single-dose-fraction vs. multifraction schedules. Results: This paper outlines parameters within which radiation therapy's role might be defined, and proposes a clinical radiation-biology scoring program to evaluate radiation effects, based on the SOMA concept. Conclusion: A prospective, controlled clinical trial is feasible and is indicated to determine radiation therapy's role in managing the proliferative component of age-related macular degeneration

  9. Dosimetric measurements and radiobiological consequences of radioimmunotherapy in tumor bearing mice

    International Nuclear Information System (INIS)

    With the development of the hybridoma technology, the production of highly specific tumor associated monoclonal antibodies has provided new optimism for the adjuvant delivery of therapeutic radiation doses via radioimmunotherapy. The authors have used a modified form of the well-established TL dosimetry technology to measure the dose resulting from radioimmunotherapy experiments in tumor bearing mice. Their laboratory has designed and tested a miniature CaSO4:D TLD which fits conveniently inside a 20 gauge needle for the direct implantation of the dosimeter in an animal model undergoing radiolabeled antibody therapy. Direct measurement of absorbed dose from beta and gamma radiation in the animals may be obtained upon removal of the dosimeter at animal sacrifice or by surgery. This absorbed dose data may then be related to antibody affinity and localization data obtained by serial biodistribution studies. Using p96.5 melanoma antibody with a Brown Tumor Model in athymic mice, localization indices measured in the range of 2 to 4 and scored 4 to 7 days post antibody injection, yielded a tumor dose/whole body dose ratio of 1.10 +/- 0.04 (no enhancement). The dose to liver showed marker time-dependent enhancement relative to the whole body, however. An outline of suggested control radiobiological experiments to be performed in conjunction with radioimmunotherapy experiments has been included in order to provide comparative dose response data. 11 references, 14 figures, 3 tables

  10. Impact of microgravity on radiobiological processes and efficiency of DNA repair

    Energy Technology Data Exchange (ETDEWEB)

    Horneck, G. [Radiation Biology Division, Institute of Aerospace Medicine, DLR German Aerospace Center, Linder Hohe, 51170 Cologne (Germany)

    1999-12-06

    To study the influence of microgravity on radiobiological processes in space, space experiments have been performed, using an on-board 1xg reference centrifuge as in-flight control. The trajectory of individual heavy ions was localized in relation to the biological systems by use of the Biostack concept, or an additional high dose of radiation was applied either before the mission or during the mission from an on-board radiation source. In embryonic systems, such as early developmental stages of Drosophila melanogaster and Carausius morosus, the occurrence of chromosomal translocations and larval malformations was dramatically increased in response to microgravity and radiation. It has been hypothesized that these synergistic effects might be caused by an interference of microgravity with DNA repair processes. However, recent studies on bacteria, yeast cells and human fibroblasts suggest that a disturbance of cellular repair processes in the microgravity environment might not be a complete explanation for the reported synergism of radiation and microgravity. As an alternative explanation, an impact of microgravity on signal transduction, on the metabolic/physiological state or on the chromatin structure at the cellular level, or modification of self-assembly, intercellular communication, cell migration, pattern formation or differentiation at the tissue and organ level should be considered.

  11. Impact of radiobiological considerations on epidemiological inferences of age-dependent radiosensitivity

    International Nuclear Information System (INIS)

    Current epidemiological studies of the age-dependent risk of radiogenic carcinomas are based on populations still in the early stages of cancer expression. The result is a set of logical uncertainties concerning the manner in which inferences may be drawn from the existing data. These uncertainties may be formalized and examined through the application of various radiobiological principles developed from more fundamental experimental data. Chief amongst these considerations are the time course of tumor expression, the role of relative and absolute risk models, the distribution of effects between initiation and promotion, the age-dependent fraction of time a critical cell remains in radiosensitive stages and the combinatorics of the critical cellular subpopulations. Each of these and the combinatorics of the critical cellular subpopulations. Each of these principles are examined in light of their impact on the structuring of epidemiologic data and the drawing of inferences concerning age-dependent radiogenic risk. The data on atomic bomb survivors are employed as a relevant example

  12. Radiobiology of Small Hive Beetle (Coleoptera: Nitidulidae) and Prospects for Management Using Sterile Insect

    International Nuclear Information System (INIS)

    Small hive beetle, Aethina tumida Murray (Coleoptera: Nitidulidae), is considered a serious threat to beekeeping in the Western Hemisphere, Australia, and Europe mainly due to larval feeding on honey, pollen, and brood of the European honeybee, Apis mellifera L. Control methods are limited for this pest. Studies were conducted to provide information on the radiobiology of small hive beetle and determine the potential for sterile insect releases as a control strategy. Adult males and females were equally sensitive to a radiation dose of 80 Gy and died within 5–7 d after treatment. In reciprocal crossing studies, irradiation of females only lowered reproduction to a greater extent than irradiation of males only. For matings between unirradiated males and irradiated females, mean reproduction was reduced by >99% at 45 and 60 Gy compared with controls, and no larvae were produced at 75 Gy. Irradiation of prereproductive adults of both sexes at 45 Gy under low oxygen (1–4%) caused a high level of sterility (>99%) while maintaining moderate survivorship for several weeks, and should suffice for sterile insect releases. Sterile insect technique holds potential for suppressing small hive beetle populations in newly invaded areas and limiting its spread. (author)

  13. Postoperative radiotherapy in DBCG during 30 years. Techniques, indications and clinical radiobiological experience

    Energy Technology Data Exchange (ETDEWEB)

    Overgaard, Marie; Juul Christensen, Jens (Dept. of Oncology and Dept. of Medical Physics, Aarhus Univ. Hospital, Aarhus (Denmark))

    2008-05-15

    During the time period 1977-2007 postoperative radiotherapy in DBCG has varied considerably with regard to techniques and indications together with changes in the extent of surgery and adjuvant systemic therapy. The radiation treatment has been developed on the basis of clinical, radiophysical and radiobiological principles, encompassing also practical problems such as available equipment in the different centres and at times lack of sufficient machine capacity. The paper focus especially on the comprehensive work done prior to the DBCG 82 b and c studies, in order to optimize radiotherapy in all aspects prior to the evaluation of the efficacy of this treatment modality. The results from these trials did succeed in clear evidence that radiotherapy has an important role in the multidisciplinary treatment of early breast cancer. In parallel to these studies a new and challenging use of radiotherapy after breast conserving surgery was evaluated in the DBCG TM 82 protocol. The experience obtained with different techniques in this study formed the basis for the current principles of radiotherapy after lumpectomy. Reduction of radiation related morbidity has been a major issue for the DBCG radiotherapy group, and in this aspect several studies, including quality control visits, have been carried out to make the relevant modifications and to evaluate deviations from the guidelines between the centres. The background for the changes in radiotherapy is described for each of the programme periods as well as future perspectives which will include further refinements of the target and adjustments of dose and fractionation in selected patients

  14. Radiobiological modeling of interplay between accelerated repopulation and altered fractionation schedules in head and neck cancer

    Directory of Open Access Journals (Sweden)

    Marcu Loredana

    2009-01-01

    Full Text Available Head and neck cancer represents a challenge for radiation oncologists due to accelerated repopulation of cancer cells during treatment. This study aims to simulate, using Monte Carlo methods, the response of a virtual head and neck tumor to both conventional and altered fractionation schedules in radiotherapy when accelerated repopulation is considered. Although clinical trials are indispensable for evaluation of novel therapeutic techniques, they are time-consuming processes which involve many complex and variable factors for success. Models can overcome some of the limitations encountered by trials as they are able to simulate in less complex environment tumor cell kinetics and dynamics, interaction processes between cells and ionizing radiation and their outcome. Conventional, hyperfractionated and accelerated treatment schedules have been implemented in a previously developed tumor growth model which also incorporates tumor repopulation during treatment. This study focuses on the influence of three main treatment-related parameters, dose per fraction, inter fraction interval and length of treatment gap and gap timing based on RTOG trial data on head and neck cancer, on tumor control. The model has shown that conventionally fractionated radiotherapy is not able to eradicate the stem population of the tumor. Therefore, new techniques such as hyperfractionated/ accelerated radiotherapy schedules should be employed. Furthermore, the correct selection of schedule-related parameters (dose per fraction, time between fractions, treatment gap scheduling is crucial in overcoming accelerated repopulation. Modeling of treatment regimens and their input parameters can offer better understanding of the radiobiological interactions and also treatment outcome.

  15. Radiation-induced cataract-genesis: pathophysiologic, radiobiological and clinical aspects

    International Nuclear Information System (INIS)

    Cataract-genesis is a widely reported late effect of irradiated crystalline lens. In this review the authors discussed the different aspects of radiation cataract pathogenesis, and the different mechanisms involved in the lens opacification, particularly the epithelium modifications such as epithelial cell death. The authors also reported the influence of radiation exposure on cataract formation following total body irradiation TBI) and autologous or allogeneic bone marrow transplantation for hematologic malignancies. Moreover, the radiobiological parameters are not studied for the crystalline lens of human. We applied for the first time the linear quadratic (LQ) and biological effective dose (BED) concept to TBI data. The calculated value of α/β of 1 Gy is in the range of the values reported for the other late responding tissues. The other risk factors for cataract development after TBI such as age, gender, central nervous system boost, long-term steroid therapy and heparin administration are discussed. In terms of cataract or sicca syndrome prevention, numerous compounds have been successfully tested in experimental models or used for the prevention of radiation-induced xerostomia in patients treated for head and neck cancer. However, none of them has been clinically evaluated for ocular radiation late effects prevention. In this report the authors discussed some of the radioprotectors potentially interesting for radiation-induced cataract or sicca syndrome prevention. (author)

  16. Osteopontin and splice variant expression level in human malignant glioma: Radiobiologic effects and prognosis after radiotherapy

    International Nuclear Information System (INIS)

    Background and purpose: We investigated the role of the hypoxia-associated secreted glycoprotein osteopontin (OPN) in the response of malignant glioma to radiotherapy by characterizing OPN and its splice variants in vitro and in patient material. Material and methods: The effect of siRNA knockdown of OPN splice variants on cellular and radiobiologic behavior was analyzed in U251MG cells using OpnS siRNA (inhibition of all OPN splice variants) and OpnAC siRNA (knockdown only of OPNa and OPNc). OPN and splice variant mRNA levels were quantified in archival material of 41 glioblastoma tumor samples. Plasma OPN was prospectively measured in 33 malignant glioma patients. Results: Inhibition of OPNa and OPNc (OpnAC) reduced clonogenic survival in U251MG cells but did not affect proliferation, migration or apoptosis. Knockdown of all OPN splice variants (OpnS) resulted in an even stronger inhibition of clonogenic survival, while cell proliferation and migration were reduced and rate of apoptosis was increased. Additional irradiation had additive effects with both siRNAs. Plasma OPN increased continuously in malignant glioma patients and was associated with poor survival. Conclusions: OPNb is partially able to compensate the effects of OPNa and OPNc knockdown in U251MG cells. High OPN plasma levels at the end of radiotherapy are associated with poor survival

  17. Water versus DNA: new insights into proton track-structure modelling in radiobiology and radiotherapy.

    Science.gov (United States)

    Champion, C; Quinto, M A; Monti, J M; Galassi, M E; Weck, P F; Fojón, O A; Hanssen, J; Rivarola, R D

    2015-10-21

    Water is a common surrogate of DNA for modelling the charged particle-induced ionizing processes in living tissue exposed to radiations. The present study aims at scrutinizing the validity of this approximation and then revealing new insights into proton-induced energy transfers by a comparative analysis between water and realistic biological medium. In this context, a self-consistent quantum mechanical modelling of the ionization and electron capture processes is reported within the continuum distorted wave-eikonal initial state framework for both isolated water molecules and DNA components impacted by proton beams. Their respective probability of occurrence-expressed in terms of total cross sections-as well as their energetic signature (potential and kinetic) are assessed in order to clearly emphasize the differences existing between realistic building blocks of living matter and the controverted water-medium surrogate. Consequences in radiobiology and radiotherapy will be discussed in particular in view of treatment planning refinement aiming at better radiotherapy strategies. PMID:26406277

  18. Radiobiological investigation on the ray induced sterilization of east worm (Grapholita molesta busc., lepidoptera:tortricidae)

    International Nuclear Information System (INIS)

    Results of radiobiological investigations on the sterilizing effect of the ionizing radiation, used to treat pupae and imagines of the oriental fruit moth (G. molesta) are reported. The irradiation is realized with gamma rays (60Co) of 12-13 Gy/s (±5%). The parameters of the induced sterility are determined differently for male and female specimen. The sterilizing effect of gamma radiation on male specimen irradiated as pupae and adults results in lethal spermatozoa mutations. The functional interrelation (dose-dominant lethals) is described by curves of a mixed type, consisting of a linear and non-linear component. The established dynamics in the frequency of the mutations in the dose range suggests that the optimum sterilizing ray doses are in the range 400-500 Gy. Doses below 500 Gy (pupae) and 450 Gy (imago) do not reduce considerably the life of the male butterflies. The sterilizing effect on the female specimen after pupae and imagines irradiation is due to dominant lethal mutations in the oocytes. The interrelation (dose-dominant lethals) is described by curves of sigmoid configuration. The absolutely sterilizing dose for both ontogenic stages is 150 Gy. The irradiation of the female specimen causes partial sterility along with the induction of dominant lethals in the ovules

  19. Environmental Research Division annual report: Center for Human Radiobiology, July 1983-June 1984. Part 2

    International Nuclear Information System (INIS)

    Epidemiological studies of the late effects of internal radium in man, and mechanistic investigations of those effects, have continued. The current status of the study is summarized. An experimental technique for preparing thin sections of bone and the application of that technique in studying the comparative distribution of radium and plutonium are described. Radiological dental changes due to radium in man and dog are compared. Survival of human fibroblasts irradiated with alpha particles in vitro was found to be higher when the average LET was higher. In the study of the late effects of thorium in man, the relative activities of the daughter products in the lung have been determined spectrometrically in vivo. The exhalation of thoron in these persons has been investigated in relation to lung burden of thorium and to personal factors such as smoking, age, and weight. The administration of two isotopes to large mammals has been used to demonstrate that the metabolism of plutonium is independent of route of entry and to determine the gastrointestinal absorption of plutonium. The effect of thermoluminescence on a scintillation radon counting system has been investigated quantitatively. Data on the exposure of 88 persons to radium were added to the data base, bringing the total to 2400 radium cases under study by the Center for Human Radiobiology. Separate abstracts were prepared for individual papers

  20. Bucharest cyclotron as intense fast neutron source for radiobiological and analytical applications

    International Nuclear Information System (INIS)

    Due to interest for applications in radiobiology and material testing, Bucharest U-120 classical variable energy Cyclotron is employed as an intense source of fast neutrons, using 13.5 MeV deuterons bombarding a Beryllium target placed at 20 deg against the incident beam. Energy spectra, yields, average energy and irradiation doses were determined using time-of-flight (TOF), multiple foils and thermoluminescent detectors (TLD) methods. The average energy is 5.24 MeV. The total yield at 0 deg, obtained by summing up the yields for neutron energies between the lower (0.3 MeV) and upper (17 MeV) thresholds, is 6.7 x 1016 n/sr.C.MeV. The yield of the low energy component (0.3-2 MeV) is 1.88 x 1016 n/sr.C.MeV, i.e. 28% of the total yield at 0 deg. We present studies on the influence of thyotepa, thyroxine, metallic ions (Cs1+ and AL3+) and D3 vitamin on fast neutron radiolysis in tumor DNA conclusions on the role of thyotepa (accelerator for tumor destruction) and of thyroxine, metallic ions and D3 vitamin (protectors). The potential for elemental analysis, especially for light elements (O, Na, Mg, Al, Si) on archaeological glass and ceramics objects is discussed. (authors)

  1. The challenge for the paradigms heat have guided the radiobiology in the past

    International Nuclear Information System (INIS)

    Until recently, it has been commonly accepted that the biological consequences following ionizing radiation exposure are attributable to direct DNA damage. However, in the last decade some evidence have emerged to suggest that the classical genetic effects associated with radiation exposure (i.e. mutations, chromosomal aberrations, micronucleus) are not necessarily the result of the direct damage induced in the cellular DNA. These effects have been termed non-targeted and include radiation-induced genomic instability, effects detected after cytoplasmic irradiation and bystander effects. All of them support the hypothesis that important genetic consequences of radiation may arise in cells that in themselves receive no direct radiation exposure at all. The radioinduced damage signals could be transmitted to these cells from those that have been directly irradiated. The non-targeted effects challenge the paradigms that have guided radiobiology in the past and may change our thinking about the early events in the carcinogenic process and in particular about the critical targets for genetic and carcinogenic damage by radiation. These effects could be particularly important at low doses, when non all the cells are directly exposed to an ionizing track. (Author) 45 refs

  2. Biological effects of embedded depleted uranium (DU). Summary of Armed Forces Radiobiology Research Institute research

    International Nuclear Information System (INIS)

    The Persian Gulf War resulted in injuries of US Coalition personnel by fragments of depleted uranium (DU). Fragments not immediately threatening the health of the individuals were allowed to remain in place, based on long-standing treatment protocols designed for other kinds of metal shrapnel injuries. However, questions were soon raised as to whether this approach is appropriate for a metal with the unique radiological and toxicological properties of DU. The Armed Forces Radiobiology Research Institute (AFRRI) is investigating health effects of embedded fragments of DU to determine whether current surgical fragment removal policies remain appropriate for this metal. These studies employ rodents implanted with DU pellets as well as cultured human cells exposed to DU compounds. Results indicate uranium from implanted DU fragments distributed to tissues far-removed from implantation sites, including bone, kidney, muscle, and liver. Despite levels of uranium in the kidney that were nephrotoxic after acute exposure, no histological or functional kidney toxicity was observed. However, results suggest the need for further studies of long-term health impact, since DU was found to be mutagenic, and it transformed human osteoblast cells to a tumorigenic phenotype. It also altered neurophysiological parameters in rat hippocampus, crossed the placental barrier, and entered fetal tissue. This report summarizes AFRRI's depleted uranium research to date

  3. Radiobiological characterization of different energy-photon beams used in radiotherapy from linear accelerator

    International Nuclear Information System (INIS)

    The main objective of this study was to perform a radiobiological characterization of different energy photon beams (6 MV and 15 MV) from linear accelerator used in radiotherapy, and comparison of different treatment modalities, with special regard to late effects of radiation. Using two end points, cell survival and micronucleus induction, in the biological system (Chines hamster V79 cell line). Chromosomes number was counted and found to be 22 chromosomes per cell. Cells were kept in confluent growth for two days and then exposed to two photon beams and immediately after irradiation were counted and re seeded in different numbered for each dose. For evaluation of surviving fraction samples were incubated at 37oC for 6 days, five samples were counted for each dose. At the same time three samples were seeded for the micronuclei frequency and incubated at 37oC after 24 hours cytochalasin-B was added to block cells in cytokinesis. The survival curve showed similar curves for the two beams and decreased with dose. The micronuclei frequency was positively correlated with dose and the energy of the photon. This indicates the presence of low dose of photoneutrons produced by using high energy photon beams. (Author)

  4. Neutron flux characterisation of the Pavia TRIGA Mark II research reactor for radiobiological and microdosimetric applications.

    Science.gov (United States)

    Alloni, D; Prata, M; Salvini, A; Ottolenghi, A

    2015-09-01

    Nowadays the Pavia TRIGA reactor is available for national and international collaboration in various research fields. The TRIGA Mark II nuclear research reactor of the Pavia University offers different in- and out-core neutron irradiation channels, each characterised by different neutron spectra. In the last two years a campaign of measurements and simulations has been performed in order to guarantee a better characterisation of these different fluxes and to meet the demands of irradiations that require precise information on these spectra in particular for radiobiological and microdosimetric studies. Experimental data on neutron fluxes have been collected analysing and measuring the gamma activity induced in thin target foils of different materials irradiated in different TRIGA experimental channels. The data on the induced gamma activities have been processed with the SAND II deconvolution code and finally compared with the spectra obtained with Monte Carlo simulations. The comparison between simulated and measured spectra showed a good agreement allowing a more precise characterisation of the neutron spectra and a validation of the adopted method. PMID:25958412

  5. Radiograaff, a proton irradiation facility for radiobiological studies at a 4 MV Van de Graaff accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Constanzo, J. [Université de Lyon, F-69622, Lyon (France); Université Lyon 1, Villeurbanne (France); CNRS/IN2P3, Institut de Physique Nucléaire de Lyon, F-69622 Villeurbanne (France); Fallavier, M., E-mail: m.fallavier@ipnl.in2p3.fr [Université de Lyon, F-69622, Lyon (France); Université Lyon 1, Villeurbanne (France); CNRS/IN2P3, Institut de Physique Nucléaire de Lyon, F-69622 Villeurbanne (France); Alphonse, G. [Université de Lyon, F-69622, Lyon (France); Université Lyon 1, Villeurbanne (France); Faculté de Médecine Lyon-Sud, LRCM, F-69921 Oullins (France); Hospices-Civils-de-Lyon, CHLS, F-69495 Pierre-Bénite (France); Bernard, C. [Université de Lyon, F-69622, Lyon (France); Université Lyon 1, Villeurbanne (France); CNRS/IN2P3, Institut de Physique Nucléaire de Lyon, F-69622 Villeurbanne (France); Battiston-Montagne, P. [Université de Lyon, F-69622, Lyon (France); Université Lyon 1, Villeurbanne (France); Faculté de Médecine Lyon-Sud, LRCM, F-69921 Oullins (France); Rodriguez-Lafrasse, C. [Université de Lyon, F-69622, Lyon (France); Université Lyon 1, Villeurbanne (France); Faculté de Médecine Lyon-Sud, LRCM, F-69921 Oullins (France); Hospices-Civils-de-Lyon, CHLS, F-69495 Pierre-Bénite (France); and others

    2014-09-01

    A horizontal beam facility for radiobiological experiments with low-energy protons has been set up at the 4 MV Van de Graaff accelerator of the Institut de Physique Nucléaire de Lyon. A homogeneous irradiation field with a suitable proton flux is obtained by means of two collimators and two Au-scattering foils. A monitoring chamber contains a movable Faraday cup, a movable quartz beam viewer for controlling the intensity and the position of the initial incident beam and four scintillating fibers for beam monitoring during the irradiation of the cell samples. The beam line is ended by a thin aluminized Mylar window (12 μm thick) for the beam extraction in air. The set-up was simulated by the GATE v6.1 Monte-Carlo platform. The measurement of the proton energy distribution, the evaluation of the fluence-homogeneity over the sample and the calibration of the monitoring system were performed using a silicon PIPS detector, placed in air in the same position as the biological samples to be irradiated. The irradiation proton fluence was found to be homogeneous to within ±2% over a circular field of 20 mm diameter. As preliminary biological experiment, two Human Head and Neck Squamous Carcinoma Cell lines (with different radiosensitivities) were irradiated with 2.9 MeV protons. The measured survival curves are compared to those obtained after X-ray irradiation, giving a Relative Biological Efficiency between 1.3 and 1.4.

  6. Radiograaff, a proton irradiation facility for radiobiological studies at a 4 MV Van de Graaff accelerator

    International Nuclear Information System (INIS)

    A horizontal beam facility for radiobiological experiments with low-energy protons has been set up at the 4 MV Van de Graaff accelerator of the Institut de Physique Nucléaire de Lyon. A homogeneous irradiation field with a suitable proton flux is obtained by means of two collimators and two Au-scattering foils. A monitoring chamber contains a movable Faraday cup, a movable quartz beam viewer for controlling the intensity and the position of the initial incident beam and four scintillating fibers for beam monitoring during the irradiation of the cell samples. The beam line is ended by a thin aluminized Mylar window (12 μm thick) for the beam extraction in air. The set-up was simulated by the GATE v6.1 Monte-Carlo platform. The measurement of the proton energy distribution, the evaluation of the fluence-homogeneity over the sample and the calibration of the monitoring system were performed using a silicon PIPS detector, placed in air in the same position as the biological samples to be irradiated. The irradiation proton fluence was found to be homogeneous to within ±2% over a circular field of 20 mm diameter. As preliminary biological experiment, two Human Head and Neck Squamous Carcinoma Cell lines (with different radiosensitivities) were irradiated with 2.9 MeV protons. The measured survival curves are compared to those obtained after X-ray irradiation, giving a Relative Biological Efficiency between 1.3 and 1.4

  7. Radiobiology of Small Hive Beetle (Coleoptera: Nitidulidae) and Prospects for Management Using Sterile Insect Releases.

    Science.gov (United States)

    Downey, Danielle; Chun, Stacey; Follett, Peter

    2015-06-01

    Small hive beetle, Aethina tumida Murray (Coleoptera: Nitidulidae), is considered a serious threat to beekeeping in the Western Hemisphere, Australia, and Europe mainly due to larval feeding on honey, pollen, and brood of the European honeybee, Apis mellifera L. Control methods are limited for this pest. Studies were conducted to provide information on the radiobiology of small hive beetle and determine the potential for sterile insect releases as a control strategy. Adult males and females were equally sensitive to a radiation dose of 80 Gy and died within 5-7 d after treatment. In reciprocal crossing studies, irradiation of females only lowered reproduction to a greater extent than irradiation of males only. For matings between unirradiated males and irradiated females, mean reproduction was reduced by >99% at 45 and 60 Gy compared with controls, and no larvae were produced at 75 Gy. Irradiation of prereproductive adults of both sexes at 45 Gy under low oxygen (1-4%) caused a high level of sterility (>99%) while maintaining moderate survivorship for several weeks, and should suffice for sterile insect releases. Sterile insect technique holds potential for suppressing small hive beetle populations in newly invaded areas and limiting its spread. PMID:26470205

  8. Decontamination activities at the National Institute of Oncology and Radiobiology in Havana, Cuba

    International Nuclear Information System (INIS)

    The National Institute of Oncology and Radiobiology had a facility contaminated with 137Cs. The contamination was produced by a leaking source stored in the place. First decontamination work was performed in 1988. Some highly contaminated floor tiles and other contaminated items were removed. Spent sealed sources stored in the facility were collected. The facility was closed because of the remaining contamination. As the Regulatory Body allowed the unrestricted use of the facility, decontamination and decommissioning were needed. D and D activities were requested to the CPHR. Contamination surveys conducted in 1999 confirmed the extent of contamination with 137Cs. Items inside the contaminated area were carefully monitored and segregated. Six Radium sources were recovered. Physical and chemical methods of decontamination were used. For different reasons, the requirements established by the Regulatory Authority for decommissioning could not be achieved, and therefore the facility could not be released from regulatory control. A Radiological Status Report was done explaining the high cost of decontamination according to the established clearance levels. New alternatives were then proposed for decommissioning of this facility. (author)

  9. Differential two colour X-ray radiobiology of membrane/cytoplasm yeast cells

    International Nuclear Information System (INIS)

    This report describes the experiment entitled 'Differential Two Colour X-Ray Radiobiology of Membrane/Cytoplasm Yeast Cells'; carried out at the Central Laser Facility (CLF) from the 6th January to the 3rd February 1997. The experiment, funded by the Framework IV Large-Scale Facilities Access Scheme, was proposed by Dr. M. Milani, Dipartimento di Scienza dei Materiali, University of Milan, Italy, and carried out by visiting researchers from his institute, the University of Modena and with technical support from the Central Laser Facility, Rutherford Appleton Laboratory. Experimental highlights: The development of an investigation technique based on the use of very soft X-ray in order to damage specific structures inside the cell structure (specifically cell wall and membrane); the use of pressure sensors as a diagnostics of cell response which allows to monitor cell response over a large range of times from fast response up to several hours; the use of dry yeast cells as an 'easy to handle' type of sample; the development of a simple model for X-ray dosimetry of the different cell compartments; the study of metabolic oscillation in yeast cell suspension and the observation of the oscillation frequency shift following an exposure to soft X-rays. (author)

  10. Water versus DNA: new insights into proton track-structure modelling in radiobiology and radiotherapy

    International Nuclear Information System (INIS)

    Water is a common surrogate of DNA for modelling the charged particle-induced ionizing processes in living tissue exposed to radiations. The present study aims at scrutinizing the validity of this approximation and then revealing new insights into proton-induced energy transfers by a comparative analysis between water and realistic biological medium. In this context, a self-consistent quantum mechanical modelling of the ionization and electron capture processes is reported within the continuum distorted wave-eikonal initial state framework for both isolated water molecules and DNA components impacted by proton beams. Their respective probability of occurrence—expressed in terms of total cross sections—as well as their energetic signature (potential and kinetic) are assessed in order to clearly emphasize the differences existing between realistic building blocks of living matter and the controverted water-medium surrogate. Consequences in radiobiology and radiotherapy will be discussed in particular in view of treatment planning refinement aiming at better radiotherapy strategies. (paper)

  11. Neutron flux characterisation of the Pavia Triga Mark II research reactor for radiobiological and microdosimetric applications

    International Nuclear Information System (INIS)

    Nowadays the Pavia TRIGA reactor is available for national and international collaboration in various research fields. The TRIGA Mark II nuclear research reactor of the Pavia University offers different in- and out-core neutron irradiation channels, each characterised by different neutron spectra. In the last two years a campaign of measurements and simulations has been performed in order to guarantee a better characterisation of these different fluxes and to meet the demands of irradiations that require precise information on these spectra in particular for radiobiological and microdosimetric studies. Experimental data on neutron fluxes have been collected analysing and measuring the gamma activity induced in thin target foils of different materials irradiated in different TRIGA experimental channels. The data on the induced gamma activities have been processed with the SAND II deconvolution code and finally compared with the spectra obtained with Monte Carlo simulations. The comparison between simulated and measured spectra showed a good agreement allowing a more precise characterisation of the neutron spectra and a validation of the adopted method. (authors)

  12. Dosimetric validation of the MCNPX Monte Carlo simulation for radiobiologic studies of megavoltage grid radiotherapy

    International Nuclear Information System (INIS)

    Purpose: To validate the MCNPX Monte Carlo simulation for radiobiologic studies of megavoltage grid radiotherapy. Methods and Materials: EDR2 films, a scanning water phantom with microionization chamber and MCNPX Monte Carlo code, were used to study the dosimetric characteristics of a commercially available megavoltage grid therapy collimator. The measured dose profiles, ratios between maximum and minimum doses at 1.5 cm depth, and percentage depth dose curve were compared with those obtained in the simulations. The simulated two-dimensional dose profile and the linear-quadratic formalism of cell survival were used to calculate survival statistics of tumor and normal cells for the treatment of melanoma with a list of doses of the fractionated grid therapy. Results: A good agreement between the simulated and measured dose data was found. The therapeutic ratio based on normal cell survival has been defined and calculated for treating both the acute and late responding melanoma tumors. The grid therapy in this study was found to be advantageous for treating the acutely responding tumors, but not for late responding tumors. Conclusions: Monte Carlo technique was demonstrated to be able to provide the dosimetric characteristics for grid therapy. The therapeutic ratio was dependent not only on the single α/β value, but also on the individual α and β values. Acutely responding tumors and radiosensitive normal tissues are more suitable for using the grid therapy

  13. Radiobiological impact of dose calculation algorithms on biologically optimized IMRT lung stereotactic body radiation therapy plans

    International Nuclear Information System (INIS)

    The aim of this study is to evaluate the radiobiological impact of Acuros XB (AXB) vs. Anisotropic Analytic Algorithm (AAA) dose calculation algorithms in combined dose-volume and biological optimized IMRT plans of SBRT treatments for non-small-cell lung cancer (NSCLC) patients. Twenty eight patients with NSCLC previously treated SBRT were re-planned using Varian Eclipse (V11) with combined dose-volume and biological optimization IMRT sliding window technique. The total dose prescribed to the PTV was 60 Gy with 12 Gy per fraction. The plans were initially optimized using AAA algorithm, and then were recomputed using AXB using the same MUs and MLC files to compare with the dose distribution of the original plans and assess the radiobiological as well as dosimetric impact of the two different dose algorithms. The Poisson Linear-Quadatric (PLQ) and Lyman-Kutcher-Burman (LKB) models were used for estimating the tumor control probability (TCP) and normal tissue complication probability (NTCP), respectively. The influence of the model parameter uncertainties on the TCP differences and the NTCP differences between AAA and AXB plans were studied by applying different sets of published model parameters. Patients were grouped into peripheral and centrally-located tumors to evaluate the impact of tumor location. PTV dose was lower in the re-calculated AXB plans, as compared to AAA plans. The median differences of PTV(D95%) were 1.7 Gy (range: 0.3, 6.5 Gy) and 1.0 Gy (range: 0.6, 4.4 Gy) for peripheral tumors and centrally-located tumors, respectively. The median differences of PTV(mean) were 0.4 Gy (range: 0.0, 1.9 Gy) and 0.9 Gy (range: 0.0, 4.3 Gy) for peripheral tumors and centrally-located tumors, respectively. TCP was also found lower in AXB-recalculated plans compared with the AAA plans. The median (range) of the TCP differences for 30 month local control were 1.6 % (0.3 %, 5.8 %) for peripheral tumors and 1.3 % (0.5 %, 3.4 %) for centrally located tumors. The lower TCP

  14. 3H-thymidine (3HTdR) incorporated into DNA; Dosimetric and radiobiological considerations

    International Nuclear Information System (INIS)

    Tritium can be selectively incorporated into DNA in vivo by administration of tritiated thymidine (3HTdR), and this labelled precursor is used widely and effectively in investigations on the mechanism of DNA synthesis, in studies on the kinetics of cell proliferation, and for the purpose of selective cell destruction. It is important, of course, to be aware of the threshold for toxicity of the isotope used in this manner. In addition, the unique dosimetric features involved present theoretical and practical problems, the solutions of which will shed light on mechanisms of radiobiology effect. The highly selective irradiation of the nucleus of those cells which incorporated 3HTdR at the time of DNA synthesis constitutes not only partial-body irradiation, but partial-cell irradiation, and homogeneity of exposure can be defined only in terms of subcellular dimensions. The toxicity of 3HTdR and the associated problems have been reviewed extensively. The object of the present paper is to: (a) evaluate from data in the literature and from data to be presented, whether observed effects from intranuclear 3H can be accounted for on the basis of calculated absorbed dose in rads to the cell nucleus, or, alternatively, whether additional factors deriving from the presence of the 3H in the DNA molecule must be invoked. In the latter case the biological effects would not be generally predictable on the basis of absorbed dose; and (b) to discuss the implications of the findings with respect to radiobiology and radiation protection. The conclusion is reached that while data are as yet inadequate for firm evaluation, biological effects of 3HTdR are those predictable on the basis of the average absorbed dose to the nucleus. The applicability of the absorbed dose concept can be evaluated satisfactorily only if adequate comparisons of the effect of incorporated 3HTdR can be made with a suitable standard external radiation such as X-rays, or possibly with the same isotope (3H

  15. In vitro and in vivo ion beam targeted micro-irradiation for radiobiology

    International Nuclear Information System (INIS)

    The main goal of radiobiology is to understand the effects of ionizing radiations on the living. These past decades, ion microbeams have shown to be important tools to study for example the effects of low dose exposure, or the bystander effect. Since 2003, the CENBG has been equipped with a system to perform targeted micro-irradiation of living samples. Recently, microbeams applications on this subject have diversified and the study of DNA repair mechanisms at the cellular and multicellular scales, in vitro and in vivo, has become possible thanks to important evolutions of fluorescence imaging techniques and cellular biology. To take into account these new approaches, the CENBG micro-irradiation beamline has been entirely redesigned and rebuilt to implement new features and to improve the existing ones. My PhD objectives were i) commissioning the facility, ii) characterizing the system on track etch detectors, and on living samples, iii) implementing protocols to perform targeted irradiations of living samples with a con-trolled delivered dose, at the cellular and multicellular scales, and to visualize the early consequences online, iv) modelling these irradiations to explain the biological results using the calculated physical data. The work of these past years has allowed us i) to measure the performances of our system: a beam spot size of about 2 μm and a targeting accuracy of ± 2 μm, and to develop ion detection systems for an absolute delivered dose control, ii) to create highly localized radiation-induced DNA damages and to see online the recruitment of DNA repair proteins, iii) to apply these protocols to generate radiation-induced DNA damages in vivo inside a multicellular organism at the embryonic stage: Caenorhabditis elegans. These results have opened up many perspectives on the study of the interaction between ionizing radiations and the living, at the cellular and multicellular scales, in vitro and in vivo. (author)

  16. Radiobiological investigations at tumor cell lines by exploiting aspects of chronological dose administration

    Directory of Open Access Journals (Sweden)

    Waldemar Ulmer

    2014-08-01

    Full Text Available Purpose: Using 31P-NMR spectroscopy the chronological behavior of the ATP-metabolism of the tumor spheroids C3H-MA, 9L-Gliome and the mono-layer L1210 has been analyzed via increase and decrease of the β-peak. The goal of this study is to elaborate an optimal fractionation scheme with regard to the irradiation of tumor spheroids and possibly to human tumors.  Methods: The NMR-spectroscopy has been carried out by the FID technique (free induction decay, and the intensity of the β-peak provides a measure of the survival fraction S after radiation exposure with 30 kV X-rays. The linear-quadratic model has to be generalized in order to be valid for irradiation beyond the shoulder. Results and Conclusion: All three cell lines show characteristic periods, and a homeostatic control cannot be recognized. Essential components of these periods are circadian (i.e. one day, circa-semiseptan (i.e. 3.5 days and circa-septan (i.e. one week. The determination of the survival fractions provides an optimum exploitation of radiation damages, when the ATP-concentration assumes a maximum value. This optimum is reached, when all three cycles exhibit an ATP maximum, which is only possible by accounting for the circa-septan rhythm.--------------------------------------Cite this article as: Ulmer W. Radiobiological investigations at tumor cell lines by exploiting aspects of chronological dose administration. Int J Cancer Ther Oncol 2014; 2(3:020312. DOI:10.14319/ijcto.0203.12 

  17. Functional and histological assessment of the radiobiology of normal rat lung in BNCT

    International Nuclear Information System (INIS)

    This study investigated the radiobiology and sensitivity of the normal rat lung to Boron Neutron Capture Therapy (BNCT) radiation. Rat thorax irradiations were carried out with x-rays or with neutrons in the presence or absence of p-boronophenylalanine (BPA). Lung damage were assessed functionally with breathing rate measurement up to 180 days after irradiation and then histologically. Breathing rates 20% (∼3 σ) above the control group (sham-irradiated rats) mean were considered as positive responses to lung radiation damage. Though most responding animals demonstrated radiation induced pneumonitis (≤110 days) as well as pulmonary fibrosis (>110 days), some animals receiving neutrons plus BPA showed only the latter. The breathing rate dose response data were fit using probit analysis. The ED50 values measured for x-rays, neutron beam only, and neutrons plus BPA were 11.5±0.4 Gy, 9.2±0.5 Gy, and 6.7±0.4 Gy, respectively. The biological weighting factors for the neutron beam (n+γ), the thermal neutron dose component, and the 10B dose component were determined to be 1.2±0.1, 2.2±0.4, and 2.3±0.3, respectively. The histological dose response curves were linear. Consistent with the functional assay, the weighting factors measured histologically were 1.2±0.1 for the thermal neutron beam and 1.9±0.2 for the 10B dose component. (author)

  18. Realization of radiobiological in vitro cell experiments at conventional X-ray tubes and unconventional radiation sources

    International Nuclear Information System (INIS)

    More than hundred years after the discovery of X-rays different kinds of ionizing radiation are ubiquitous in medicine, applied to clinical diagnostics and cancer treatment as well. Irrespective of their nature, the widespread application of radiation implies its precise dosimetric characterization and detailed knowledge of the radiobiological effects induced in cancerous and normal tissue. Starting with in vitro cell irradiation experiments, which define basic parameters for the subsequent tissue and animal studies, the whole multi-stage process is completed by clinical trials that translate the results of fundamental research into clinical application. In this context, the present dissertation focuses on the establishment of radiobiological in vitro cell experiments at unconventional, but clinical relevant radiation qualities. In the first part of the present work the energy dependent biological effectiveness of photons was studied examining low-energy X-rays (≤ 50 keV), as used for mammography, and high-energy photons (≥ 20 MeV) as proposed for future radiotherapy. Cell irradiation experiments have been performed at conventional X-ray tubes providing low-energy photons and 200 kV reference radiation as well. In parallel, unconventional quasi-monochromatic channeling X-rays and high-energy bremsstrahlung available at the radiation source ELBE of the Forschungszentrum Dresden-Rossendorf were considered for radiobiological experimentation. For their precise dosimetric characterization dosimeters based on the thermally stimulated emission of exoelectrons and on radiochromic films were evaluated, whereas just the latter was found to be suitable for the determination of absolute doses and spatial dose distributions at cell position. Standard ionization chambers were deployed for the online control of cell irradiation experiments. Radiobiological effects were analyzed in human mammary epithelial cells on different subcellular levels revealing an increasing amount

  19. Realization of radiobiological in vitro cell experiments at conventional X-ray tubes and unconventional radiation sources

    Energy Technology Data Exchange (ETDEWEB)

    Beyreuther, Elke

    2010-09-10

    More than hundred years after the discovery of X-rays different kinds of ionizing radiation are ubiquitous in medicine, applied to clinical diagnostics and cancer treatment as well. Irrespective of their nature, the widespread application of radiation implies its precise dosimetric characterization and detailed knowledge of the radiobiological effects induced in cancerous and normal tissue. Starting with in vitro cell irradiation experiments, which define basic parameters for the subsequent tissue and animal studies, the whole multi-stage process is completed by clinical trials that translate the results of fundamental research into clinical application. In this context, the present dissertation focuses on the establishment of radiobiological in vitro cell experiments at unconventional, but clinical relevant radiation qualities. In the first part of the present work the energy dependent biological effectiveness of photons was studied examining low-energy X-rays (≤ 50 keV), as used for mammography, and high-energy photons (≥ 20 MeV) as proposed for future radiotherapy. Cell irradiation experiments have been performed at conventional X-ray tubes providing low-energy photons and 200 kV reference radiation as well. In parallel, unconventional quasi-monochromatic channeling X-rays and high-energy bremsstrahlung available at the radiation source ELBE of the Forschungszentrum Dresden-Rossendorf were considered for radiobiological experimentation. For their precise dosimetric characterization dosimeters based on the thermally stimulated emission of exoelectrons and on radiochromic films were evaluated, whereas just the latter was found to be suitable for the determination of absolute doses and spatial dose distributions at cell position. Standard ionization chambers were deployed for the online control of cell irradiation experiments. Radiobiological effects were analyzed in human mammary epithelial cells on different subcellular levels revealing an increasing amount

  20. High value of the radiobiological parameter Dq correlates to expression of the transforming growth factor beta type II receptor in a panel of small cell lung cancer cell lines

    DEFF Research Database (Denmark)

    Hougaard, S; Krarup, M; Nørgaard, P; Damstrup, L; Spang-Thomsen, M; Poulsen, H S

    1998-01-01

    Our panel of SCLC cell lines have previously been examined for their radiobiological characteristics and sensitivity to treatment with TGF beta 1. In this study we examined the possible correlations between radiobiological parameters and the expression of the TGF beta type II receptor (TGF beta...... role for the repair of radiation induced DNA damage in SCLC....

  1. Automation of the particle dosimetry and the dose application for radiobiological experiments at a vertical proton beam

    CERN Document Server

    Moertel, H; Eyrich, W; Fritsch, M; Distel, L

    2002-01-01

    A facility with a vertical beam for radiobiological experiments with low-energy protons has been setup at the Tandem accelerator at Erlangen. This energy region is optimal to investigate the biological effects of the linear energy transfer in the Bragg region under physiological conditions. A new automated data acquisition system for dosimetry and monitoring based on a personal computer was developed and optimized for this setup. A specially designed sample holder offers possibilities of cooling or changing of atmosphere during irradiation. First irradiations of biological samples have shown the functionality of the setup.

  2. Automation of the particle dosimetry and the dose application for radiobiological experiments at a vertical proton beam

    Science.gov (United States)

    Mörtel, H.; Georgi, J.; Eyrich, W.; Fritsch, M.; Distel, L.

    2002-08-01

    A facility with a vertical beam for radiobiological experiments with low-energy protons has been setup at the Tandem accelerator at Erlangen. This energy region is optimal to investigate the biological effects of the linear energy transfer in the Bragg region under physiological conditions. A new automated data acquisition system for dosimetry and monitoring based on a personal computer was developed and optimized for this setup. A specially designed sample holder offers possibilities of cooling or changing of atmosphere during irradiation. First irradiations of biological samples have shown the functionality of the setup.

  3. A modular approach for assessing the effect of radiation environments on man in operational systems. The radiobiological vulnerability of man during task performance

    Science.gov (United States)

    Ewing, D. E.

    1972-01-01

    A modular approach for assessing the affects of radiation environments on man in operational systems has been developed. The feasibility of the model has been proved and the practicality has been assessed. It has been applied to one operational system to date and information obtained has been submitted to systems analysts and mission planners for the assessment of man's vulnerability and impact on systems survivability. In addition, the model has been developed so that the radiobiological data can be input to a sophisticated man-machine interface model to properly relate the radiobiological stress with other mission stresses including the effects of a degraded system.

  4. Alpha Particle Emitter Radiolabeled Antibody for Metastatic Cancer: What Can We Learn from Heavy Ion Beam Radiobiology?

    Directory of Open Access Journals (Sweden)

    Hong Song

    2012-06-01

    Full Text Available Alpha-particle emitter labeled monoclonal antibodies are being actively developed for treatment of metastatic cancer due to the high linear energy transfer (LET and the resulting greater biological efficacy of alpha-emitters. Our knowledge of high LET particle radiobiology derives primarily from accelerated heavy ion beam studies. In heavy ion beam therapy of loco-regional tumors, the modulation of steep transition to very high LET peak as the particle approaches the end of its track (known as the Bragg peak enables greater delivery of biologically potent radiation to the deep seated tumors while sparing normal tissues surrounding the tumor with the relatively low LET track segment part of the heavy ion beam. Moreover, fractionation of the heavy ion beam can further enhance the peak-to-plateau relative biological effectiveness (RBE ratio. In contrast, internally delivered alpha particle radiopharmaceutical therapy lack the control of Bragg peak energy deposition and the dose rate is determined by the administered activity, alpha-emitter half-life and biological kinetics of the radiopharmaceutical. The therapeutic ratio of tumor to normal tissue is mainly achieved by tumor specific targeting of the carrier antibody. In this brief overview, we review the radiobiology of high LET radiations learned from ion beam studies and identify the features that are also applicable for the development of alpha-emitter labeled antibodies. The molecular mechanisms underlying DNA double strand break repair response to high LET radiation are also discussed.

  5. Studies of UV-cured CR-39 recording properties in view of its applicability in radiobiological experiments with alpha particles

    International Nuclear Information System (INIS)

    In radiobiology, low doses of high-LET radiation correspond to a few particle traversals through the cell population. Therefore, for studies on cell monolayers irradiated with a low dose of α-particles, it is extremely useful if the number and position of particle traversals can be determined. In this study we describe a new method, based on UV-curing, to obtain a 10μm thick CR-39 grafted onto a 2.5μm thick PolyEthylene Terephtalate (PET). This thin double polymeric layer, used as a dish base, has a regular and reproducible detector thickness which can be traversed by 3.5MeV α-particles, with a sufficient residual energy to traverse mammalian cells attached to the base. The recording properties of a PET-CR-39 dish, together with a demonstration of its use for radiobiological experiments, are presented. This new tool allows the precise determination of single-track impact parameters at a sub-cellular level.

  6. Non-targeted effects of ionising radiation - A challenge to the current radiobiological paradigm

    International Nuclear Information System (INIS)

    A basic paradigm in radiobiology is that, after exposure to ionising radiation, the deposition of energy in the cell nucleus and the resulting damage to DNA, the primary target, are responsible for the harmful biological effects of radiation. The radiation-induced changes are thought to be fixed already in the first cell division following the radiation exposure and health effects are considered to result as a consequence of clonal proliferation of cells carrying mutations in specific genes. Since the initial damage induced in DNA has been shown to be directly proportional to dose, risk is also considered to be directly proportional to dose. Risk from multiple exposures is considered to be additive, and risk from high and low LET radiation exposure is assumed to be qualitatively the same. These assumptions are incorporated into the Linear-No-Threshold (LNT) Hypothesis that is used in all radiation protection practices. A range of evidence has now emerged that challenges the universality of the target theory of radiation induced effects. These effects have also been termed 'non-(DNA)-targeted' and include radiation-induced bystander effects, genomic instability, adaptive response, low-dose hyper-radiosensitivity, abscopal (out-of-field) effects of radiotherapy, clastogenic factors, delayed reproductive death and induction of genes by radiation. Essential features of non-targeted effects are that they do not require direct nuclear exposure by radiation and they are particularly significant at low doses. This new evidence suggests a need for a new paradigm in radiation biology. The new paradigm should cover both the classical (targeted) and the non-targeted effects. New aspects include the role of cellular communication and tissue-level responses. A better understanding of non-targeted effects may have important consequences on the health risk assessment and, consequently, on radiation protection. The non-targeted effects may contribute to the estimation of cancer

  7. Radiobiological evaluation of forward and inverse IMRT using different fractionations for head and neck tumours

    Directory of Open Access Journals (Sweden)

    Capela Miguel

    2010-06-01

    Full Text Available Abstract Purpose To quantify the radiobiological advantages obtained by an Improved Forward Planning technique (IFP and two IMRT techniques using different fractionation schemes for the irradiation of head and neck tumours. The conventional radiation therapy technique (CONVT was used here as a benchmark. Methods Seven patients with head and neck tumours were selected for this retrospective planning study. The PTV1 included the primary tumour, PTV2 the high risk lymph nodes and PTV3 the low risk lymph nodes. Except for the conventional technique where a maximum dose of 64.8 Gy was prescribed to the PTV1, 70.2 Gy, 59.4 Gy and 50.4 Gy were prescribed respectively to PTV1, PTV2 and PTV3. Except for IMRT2, all techniques were delivered by three sequential phases. The IFP technique used five to seven directions with a total of 15 to 21 beams. The IMRT techniques used five to nine directions and around 80 segments. The first, IMRT1, was prescribed with the conventional fractionation scheme of 1.8 Gy per fraction delivered in 39 fractions by three treatment phases. The second, IMRT2, simultaneously irradiated the PTV2 and PTV3 with 59.4 Gy and 50.4 Gy in 28 fractions, respectively, while the PTV1 was boosted with six subsequent fractions of 1.8 Gy. Tissue response was calculated using the relative seriality model and the Poisson Linear-Quadratic-Time model to simulate repopulation in the primary tumour. Results The average probability of total tumour control increased from 38% with CONVT to 80% with IFP, to 85% with IMRT1 and 89% with IMRT2. The shorter treatment time and larger dose per fraction obtained with IMRT2 resulted in an 11% increase in the probability of control in the PTV1 with respect to IFP and 7% relatively to IMRT1 (p Conclusions A significant improvement in treatment outcome was obtained with IMRT compared to conventional radiation therapy. The practical and biological advantages of IMRT2, employing a shorter treatment time, may

  8. Emerging issues in radiobiology and cancer research - the impact of non-targeted effects

    International Nuclear Information System (INIS)

    Since the acceptance that non-targeted effects (NTE) can be measured in unirradiated cells or distant progeny of irradiated cells, the discussion has developed about the relevance of these effects for radiobiology and radiation protection since they increase the complexity of the radiation response and allow for outcomes which are not as predictable as they were under the 'old rules'. Specific examples will be presented and analysed which challenge accepted paradigms. 1. Data show that bystander mechanisms are either on or off in cells and that the 'on' threshold appears to be at a very low dose (mGy range). 2. Data suggest that adaptive responses are induced not only in neighbouring cells but in organisms which receive bystander signals. 3. Data show that chronic exposures to alpha or gamma irradiation lead to complex responses in organisms which can be adaptive and protective. 4. Evidence suggests that mixed contaminant exposures which include radiation can have sub-additive or synergistic effects. A key consequence of findings in NTE biology is that at any given level of organization, from gene to ecosystem - communication of stress signals and heritability of stress adaptations provide the bridges linking one hierarchical level to the next and enable the rapid propagation of change triggered by stress at one level, resulting in change at a higher (or lower?) level. Evolution could thus be regulated through communicated signals between cells, individuals, and populations which control and optimize responses coordinating the emergence of exquisitely tuned systems which can adapt rapidly to micro or macro environmental change. A current view of cancer is that it is a 'systems level' disease which can not be understood or treated by looking at individual genes or pathways in the traditional way. Rather, a system approach is required with looks at the environment at both cellular and organismal levels to understand what has been perturbed. We suggest that bystander

  9. The principles of Katz's cellular track structure radiobiological model

    International Nuclear Information System (INIS)

    The cellular track structure theory (TST), introduced by Katz in 1968, applies the concept of action cross section as the probability of targets in the radiation detector being activated to elicit the observed endpoint (e.g. cell killing). The ion beam radiation field is specified by the charge Z, speed β (or energy), fluence and linear energy transfer (LET) of the ion, rather than by its total absorbed dose or dose-averaged LET. The detector is represented by radiosensitive elements of size a0 and radiosensitivity D0, its gamma-ray response being represented by c-hit or multi-target expressions rather than by the linear-quadratic formula. Key to TST is the Dδ(r) formula describing the radial distribution of delta-ray dose (RDD) around the ion path. This formula, when folded with the dose response of the detector and radially integrated, yields the 'point target' action cross section value, sPT. The averaged value of the cross section, σ, is obtained by radially integrating the a0-averaged RDD. In the 'track width' regime which may occur at the distal end of the ion's path, the value of s may considerably exceed its geometrical value, πa20. Several scaling principles are applied in TST, resulting in its simple analytic formulation. Multi-target detectors, such as cells, are represented in TST by m, D0, σ0 (the 'saturation value' of the cross section which replaces a0) and k (a 'detector saturation index'), as the fourth model parameter. With increasing LET of the ion, the two-component formulation of TST allows for successive transition from shouldered survival curves at low LET values to exponential ones at radiobiological effectiveness (RBE) maximum, followed by 'thin-down' at the end of the ion track. For a given cell line, having best-fitted the four model parameters (m, D0, σ0 and k) to an available data set of measured survival curves, TST is able to quantitatively predict cell survival and RBE for

  10. Modeling detector response in solid-state systems for radiation therapy and radiobiology

    International Nuclear Information System (INIS)

    -filled proportional counters (TEPC) where it is anticipated that intercomparisons with experiment will help to validate the use of such codes for the microdosimetry predictions on the sub-cellular scale in radiobiological systems. Monte Carlo based microdosimetry calculations are also expected to assist in explaining LET dependencies found in many solid-state detector systems. (Author)

  11. Comparison of the radiobiological effects of Boron neutron capture therapy (BNCT) and conventional Gamma Radiation

    International Nuclear Information System (INIS)

    BNCT is an experimental radiotherapeutic modality that uses the capacity of the isotope 10B to capture thermal neutrons leading to the production of 4He and 7Li, particles with high linear energy transfer (LET). The aim was to evaluate and compare in vitro the mechanisms of response to the radiation arising of BNCT and conventional gamma therapy. We measured the survival cell fraction as a function of the total physical dose and analyzed the expression of p27/Kip1 and p53 by Western blotting in cells of colon cancer (ARO81-1). Exponentially growing cells were distributed into the following groups: 1) BPA (10 ppm 10B) + neutrons; 2) BOPP (10 ppm 10B) + neutrons; 3) neutrons alone; 4) gamma-rays. A control group without irradiation for each treatment was added. The cells were irradiated in the thermal neutron beam of the RA-3 (flux= 7.5 109 n/cm2 sec) or with 60Co (1Gy/min) during different times in order to obtain total physical dose between 1-5 Gy (±10 %). A decrease in the survival fraction as a function of the physical dose was observed for all the treatments. We also observed that neutrons and neutrons + BOPP did not differ significantly and that BPA was the more effective compound. Protein extracts of irradiated cells (3Gy) were isolated to 24 h and 48 h post radiation exposure. The irradiation with neutrons in presence of 10BPA or 10BOPP produced an increase of p53 at 24 h maintain until 48 h. On the contrary, in the groups irradiated with neutrons alone or gamma the peak was observed at 48 hr. The level of expression of p27/Kip1 showed a reduction of this protein in all the groups irradiated with neutrons (neutrons alone or neutrons plus boron compound), being more marked at 24 h. These preliminary results suggest different radiobiological response for high and low let radiation. Future studies will permit establish the role of cell cycle in the tumor radio sensibility to BNCT. (author)

  12. Radiobiologic comparison of helical tomotherapy, intensity modulated radiotherapy, and conformal radiotherapy in treating lung cancer accounting for secondary malignancy risks

    International Nuclear Information System (INIS)

    The aim of the present study is to examine the importance of using measures to predict the risk of inducing secondary malignancies in association with the clinical effectiveness of treatment plans in terms of tumor control and normal tissue complication probabilities. This is achieved by using radiobiologic parameters and measures, which may provide a closer association between clinical outcome and treatment delivery. Overall, 4 patients having been treated for lung cancer were examined. For each of them, 3 treatment plans were developed based on the helical tomotherapy (HT), multileaf collimator-based intensity modulated radiation therapy (IMRT), and 3-dimensional conformal radiation therapy (CRT) modalities. The different plans were evaluated using the complication-free tumor control probability (p+), the overall probability of injury (pI), the overall probability of control/benefit (pB), and the biologically effective uniform dose (D¯¯). These radiobiologic measures were used to develop dose-response curves (p-D¯¯ diagram), which can help to evaluate different treatment plans when used in conjunction with standard dosimetric criteria. The risks for secondary malignancies in the heart and the contralateral lung were calculated for the 3 radiation modalities based on the corresponding dose-volume histograms (DVHs) of each patient. Regarding the overall evaluation of the different radiation modalities based on the p+ index, the average values of the HT, IMRT, and CRT are 67.3%, 61.2%, and 68.2%, respectively. The corresponding average values of pB are 75.6%, 70.5%, and 71.0%, respectively, whereas the average values of pI are 8.3%, 9.3%, and 2.8%, respectively. Among the organs at risk (OARs), lungs show the highest probabilities for complications, which are 7.1%, 8.0%, and 1.3% for the HT, IMRT, and CRT modalities, respectively. Similarly, the biologically effective prescription doses (DB¯¯) for the HT, IMRT, and CRT modalities are 64.0, 60.9, and 60.8 Gy

  13. Radiobiologic comparison of helical tomotherapy, intensity modulated radiotherapy, and conformal radiotherapy in treating lung cancer accounting for secondary malignancy risks

    Energy Technology Data Exchange (ETDEWEB)

    Komisopoulos, Georgios [Department of Medical Physics, Medical School, University of Patras, Patras (Greece); Mavroidis, Panayiotis, E-mail: mavroidis@uthscsa.edu [Department of Radiation Oncology, University of Texas Health Sciences Center at San Antonio, San Antonio, TX (United States); Department of Medical Radiation Physics, Karolinska Institutet and Stockholm University, Stockholm (Sweden); Rodriguez, Salvador; Stathakis, Sotirios; Papanikolaou, Nikos [Department of Radiation Oncology, University of Texas Health Sciences Center at San Antonio, San Antonio, TX (United States); Nikiforidis, Georgios C.; Sakellaropoulos, Georgios C. [Department of Medical Physics, Medical School, University of Patras, Patras (Greece)

    2014-01-01

    The aim of the present study is to examine the importance of using measures to predict the risk of inducing secondary malignancies in association with the clinical effectiveness of treatment plans in terms of tumor control and normal tissue complication probabilities. This is achieved by using radiobiologic parameters and measures, which may provide a closer association between clinical outcome and treatment delivery. Overall, 4 patients having been treated for lung cancer were examined. For each of them, 3 treatment plans were developed based on the helical tomotherapy (HT), multileaf collimator-based intensity modulated radiation therapy (IMRT), and 3-dimensional conformal radiation therapy (CRT) modalities. The different plans were evaluated using the complication-free tumor control probability (p{sub +}), the overall probability of injury (p{sub I}), the overall probability of control/benefit (p{sub B}), and the biologically effective uniform dose (D{sup ¯¯}). These radiobiologic measures were used to develop dose-response curves (p-D{sup ¯¯} diagram), which can help to evaluate different treatment plans when used in conjunction with standard dosimetric criteria. The risks for secondary malignancies in the heart and the contralateral lung were calculated for the 3 radiation modalities based on the corresponding dose-volume histograms (DVHs) of each patient. Regarding the overall evaluation of the different radiation modalities based on the p{sub +} index, the average values of the HT, IMRT, and CRT are 67.3%, 61.2%, and 68.2%, respectively. The corresponding average values of p{sub B} are 75.6%, 70.5%, and 71.0%, respectively, whereas the average values of p{sub I} are 8.3%, 9.3%, and 2.8%, respectively. Among the organs at risk (OARs), lungs show the highest probabilities for complications, which are 7.1%, 8.0%, and 1.3% for the HT, IMRT, and CRT modalities, respectively. Similarly, the biologically effective prescription doses (D{sub B}{sup ¯¯}) for the

  14. Clinical radiobiology of glioblastoma multiforme. Estimation of tumor control probability from various radiotherapy fractionation schemes

    Energy Technology Data Exchange (ETDEWEB)

    Pedicini, Piernicola [I.R.C.C.S.-Regional-Cancer-Hospital-C.R.O.B, Unit of Nuclear Medicine, Department of Radiation and Metabolic Therapies, Rionero-in-Vulture (Italy); Department of Radiation and Metabolic Therapies, I.R.C.C.S.-Regional-Cancer-Hospital-C.R.O.B, Unit of Radiotherapy, Rionero-in-Vulture (Italy); Fiorentino, Alba [Sacro Cuore - Don Calabria Hospital, Radiation Oncology Department, Negrar, Verona (Italy); Simeon, Vittorio [I.R.C.C.S.-Regional-Cancer-Hospital-C.R.O.B, Laboratory of Preclinical and Translational Research, Rionero-in-Vulture (Italy); Tini, Paolo; Pirtoli, Luigi [University of Siena and Tuscany Tumor Institute, Unit of Radiation Oncology, Department of Medicine Surgery and Neurological Sciences, Siena (Italy); Chiumento, Costanza [Department of Radiation and Metabolic Therapies, I.R.C.C.S.-Regional-Cancer-Hospital-C.R.O.B, Unit of Radiotherapy, Rionero-in-Vulture (Italy); Salvatore, Marco [I.R.C.C.S. SDN Foundation, Unit of Nuclear Medicine, Napoli (Italy); Storto, Giovanni [I.R.C.C.S.-Regional-Cancer-Hospital-C.R.O.B, Unit of Nuclear Medicine, Department of Radiation and Metabolic Therapies, Rionero-in-Vulture (Italy)

    2014-10-15

    The aim of this study was to estimate a radiobiological set of parameters from the available clinical data on glioblastoma (GB). A number of clinical trial outcomes from patients affected by GB and treated with surgery and adjuvant radiochemotherapy were analyzed to estimate a set of radiobiological parameters for a tumor control probability (TCP) model. The analytical/graphical method employed to fit the clinical data allowed us to estimate the intrinsic tumor radiosensitivity (α), repair capability (b), and repopulation doubling time (T{sub d}) in a first phase, and subsequently the number of clonogens (N) and kick-off time for accelerated proliferation (T{sub k}). The results were used to formulate a hypothesis for a scheduleexpected to significantly improve local control. The 95 % confidence intervals (CI{sub 95} {sub %}) of all parameters are also discussed. The pooled analysis employed to estimate the parameters summarizes the data of 559 patients, while the studies selected to verify the results summarize data of 104 patients. The best estimates and the CI{sub 95} {sub %} are α = 0.12 Gy{sup -1} (0.10-0.14), b = 0.015 Gy{sup -2} (0.013-0.020), α/b = 8 Gy (5.0-10.8), T{sub d} = 15.4 days (13.2-19.5), N = 1 . 10{sup 4} (1.2 . 10{sup 3} - 1 . 10{sup 5}), and T{sub k} = 37 days (29-46). The dose required to offset the repopulation occurring after 1 day (D{sub prolif}) and starting after T{sub k} was estimated as 0.30 Gy/day (0.22-0.39). The analysis confirms a high value for the α/b ratio. Moreover, a high intrinsic radiosensitivity together with a long kick-off time for accelerated repopulation and moderate repopulation kinetics were found. The results indicate a substantial independence of the duration of the overall treatment and an improvement in the treatment effectiveness by increasing the total dose without increasing the dose fraction. (orig.) [German] Schaetzung eines strahlenbiologischen Parametersatzes auf der Grundlage klinischer Daten bei

  15. Programming

    International Nuclear Information System (INIS)

    The programmer's task is often taken to be the construction of algorithms, expressed in hierarchical structures of procedures: this view underlies the majority of traditional programming languages, such as Fortran. A different view is appropriate to a wide class of problem, perhaps including some problems in High Energy Physics. The programmer's task is regarded as having three main stages: first, an explicit model is constructed of the reality with which the program is concerned; second, this model is elaborated to produce the required program outputs; third, the resulting program is transformed to run efficiently in the execution environment. The first two stages deal in network structures of sequential processes; only the third is concerned with procedure hierarchies. (orig.)

  16. 2. International conference. Radiobiological consequences of nuclear accidents; Russian-Norwegian Satellite Symposium on nuclear accidents, radioecology and health. Abstracts. Part 2

    International Nuclear Information System (INIS)

    Materials on radiobiological effect of ionizing radiation under emergency situations are presented. The radiation contamination of environmental media after the Chernobyl NPP accident (ground, earth and water ecological systems), effect of external and internal irradiation on the inhabitants of the region are estimated. Time characteristic of radiation risk of originating tumors and genetic injuries is given

  17. Proceedings of the 6rd Radiobiological conference with international participation dedicated to 20th anniversary of nuclear accident in Chernobyl, 2006

    International Nuclear Information System (INIS)

    Scientific conference deals with problems in radiobiology, photobiology and radio-environmental sciences. Some papers deal with the historical aspects development of reactor accidents (Chernobyl NPP and NPP A-1 Jaslovske Bohunice) as well as history of nuclear sciences in former Czechoslovakia. Proceedings contain forty-seven papers

  18. Radiobiology in clinical radiation therapy part II: current practice and new horizons

    International Nuclear Information System (INIS)

    Objective: This course is designed for residents in radiation oncology, preparing for their boards. It includes the physics and chemistry of the absorption of radiation, a description of the biological systems used to obtain a quantitative relationship between dose and biological effect, as well as a review of the basic principles in radiation biology that have been established. The multifraction regimens used in conventional radiotherapy were developed empirically, but can be understood in terms of radiobiological principles. Dividing the dose into many fractions reduces biological effectiveness due to repair of sublethal damage; this occurs in both tumors and normal tissues. Fractionation allows re-oxygenation to occur in tumors and so increases the effectiveness of a given total dose. Fractionation also leads to sensitization by reassortment of cycling tumor cells into radiosensitive phases of the cycle. Laboratory research also provides a rationale for modifications of existing fractionation protocols. The dose response relationship for late responding tissues is more 'curved' than for acute or early effects. Consequently the use of multiple fractions allows a greater separation of early and late effects in normal tissues. This has led to the introduction of hyperfractionation and accelerated treatment. Both involve two treatments per day (BID) but based on quite different rationales. The limitation of protraction is cell proliferation in the tumor, which may be accelerated as the tumor shrinks. Measurements of cell kinetics can identify fast growing tumors that may benefit from accelerated treatment. Hypoxia was early identified as a cause of resistance to cell killing x-rays. This led to development of electron affinic compounds as radiosensitizers of hypoxic cells. The new trend is the development of bioreductive drugs that are specifically cytotoxic to hypoxic cells i.e. hypoxic cytotoxins, but which still need to be combined with radiation. Fast neutrons

  19. Radiobiology in clinical radiation therapy - Part II: Current practice and new horizons

    International Nuclear Information System (INIS)

    Objective: This course is designed for residents in radiation oncology, preparing for their boards. The principles described in Part I are used to explain current practices in radiation oncology and as a basis for new initiatives. The multifraction regimens used in conventional radiotherapy were developed empirically, but can be understood in terms of radiobiological principles. Dividing the dose into many fractions reduces biological effectiveness due to repair of sublethal damage; this occurs in both tumors and normal tissues. Fractionation allows re-oxygenation to occur in tumors and so increases the effectiveness of a given total dose. Fractionation also leads to sensitization by reassortment of cycling tumor cells into radiosensitive phases of the cycle. Laboratory research also provides a rationale for modifications of existing fractionation protocols. The dose response relationship for late responding tissues is more 'curved' than for acute or early effects. Consequently the use of multiple fractions allows a greater separation of early and late effects in normal tissues. This has led to the introduction of hyperfractionation and accelerated treatment. Both involve two treatments per day (BID) but based on quite different rationales. The limitation of protraction is cell proliferation in the tumor, which may be accelerated as the tumor shrinks. Measurements of cell kinetics can identify fast growing tumors that may benefit from accelerated treatment. Hypoxia was early identified as a cause of resistance to cell killing by x-rays. This led to the development of electron affinic compounds as radiosensitizers of hypoxic cells. The new trend is the development of bioreductive drugs that are specifically cytotoxic to hypoxic cells i.e. hypoxic cytotoxins, but which still need to be combined with radiation. Fast neutrons were initially introduced, too, in an attempt to overcome the perceived problems of hypoxia, but clinical trials now are based on the premise

  20. Radiobiological evaluation of forward and inverse IMRT using different fractionations for head and neck tumours

    International Nuclear Information System (INIS)

    To quantify the radiobiological advantages obtained by an Improved Forward Planning technique (IFP) and two IMRT techniques using different fractionation schemes for the irradiation of head and neck tumours. The conventional radiation therapy technique (CONVT) was used here as a benchmark. Seven patients with head and neck tumours were selected for this retrospective planning study. The PTV1 included the primary tumour, PTV2 the high risk lymph nodes and PTV3 the low risk lymph nodes. Except for the conventional technique where a maximum dose of 64.8 Gy was prescribed to the PTV1, 70.2 Gy, 59.4 Gy and 50.4 Gy were prescribed respectively to PTV1, PTV2 and PTV3. Except for IMRT2, all techniques were delivered by three sequential phases. The IFP technique used five to seven directions with a total of 15 to 21 beams. The IMRT techniques used five to nine directions and around 80 segments. The first, IMRT1, was prescribed with the conventional fractionation scheme of 1.8 Gy per fraction delivered in 39 fractions by three treatment phases. The second, IMRT2, simultaneously irradiated the PTV2 and PTV3 with 59.4 Gy and 50.4 Gy in 28 fractions, respectively, while the PTV1 was boosted with six subsequent fractions of 1.8 Gy. Tissue response was calculated using the relative seriality model and the Poisson Linear-Quadratic-Time model to simulate repopulation in the primary tumour. The average probability of total tumour control increased from 38% with CONVT to 80% with IFP, to 85% with IMRT1 and 89% with IMRT2. The shorter treatment time and larger dose per fraction obtained with IMRT2 resulted in an 11% increase in the probability of control in the PTV1 with respect to IFP and 7% relatively to IMRT1 (p < 0.05). The average probability of total patient complications was reduced from 80% with CONVT to 61% with IFP and 31% with IMRT. The corresponding probability of complications in the ipsilateral parotid was 63%, 42% and 20%; in the contralateral parotid it was 50%, 20

  1. DEGRO practical guidelines for radiotherapy of non-malignant disorders. Part I: physical principles, radiobiological mechanisms, and radiogenic risk

    Energy Technology Data Exchange (ETDEWEB)

    Reichl, Berthold [Hospital Weiden, Department of Radiotherapy and Radiation Oncology, Weiden (Germany); Block, Andreas [Hospital Dortmund, Institute for Medical Radiation Physics and Radiation Protection, Dortmund (Germany); Schaefer, Ulrich [Lippe Hospital, Dept. of Radiotherapy, Lemgo (Germany); Bert, Christoph; Mueller, Reinhold [University Hospitals Erlangen, Dept. of Radiation Oncology, Erlangen (Germany); Jung, Horst [University Hospital Hamburg-Eppendorf, Dept. of Radiotherapy and Radiation Oncology, Hamburg (Germany); Roedel, Franz [University Hospital Goethe-University, Dept. of Radiotherapy and Oncology, Frankfurt am Main (Germany); Collaboration: the German Cooperative Group on Radiotherapy for Benign Diseases (GCG-BD)

    2015-09-15

    Synopsis of the introductory paragraph of the DEGRO consensus S2e-guideline recommendations for the radiotherapy of benign disorders, including physical principles, radiobiological mechanisms, and radiogenic risk. This work is based on the S2e-guideline recommendations published November 14, 2013. The basic principles of radiation physics and treatment delivery, evaluation of putative underlying radiobiological mechanisms, and the assessment of genetic and cancer risk following low-dose irradiation will be presented. Radiation therapy of benign diseases is performed according to similar physical principles as those governing treatment of malignant diseases in radiation oncology, using the same techniques and workflows. These methods comprise usage of orthovoltage X-ray units, gamma irradiation facilities, linear accelerators (LINACs), and brachytherapy. Experimental in vitro and in vivo models recently confirmed the clinically observed anti-inflammatory effect of low-dose X-irradiation, and implicated a multitude of radiobiological mechanisms. These include modulation of different immunological pathways, as well as the activities of endothelial cells, mono- and polymorphonuclear leukocytes, and macrophages. The use of effective dose for radiogenic risk assessment and the corresponding tumor incidence rate of 5.5 %/Sv are currently controversially discussed. Some authors argue that the risk of radiation-induced cancers should be estimated on the basis of epidemiological data. However, such data are rarely available at present and associated with high variability. Current radiobiological studies clearly demonstrate a therapeutic effectiveness of radiation therapy used to treat benign diseases and implicate various molecular mechanisms. Radiogenic risks should be taken into account when applying radiation treatment for benign diseases. (orig.) [German] Zusammenfassung des einfuehrenden Kapitels der DEGRO-S2e-Leitlinie zur Strahlentherapie gutartiger Erkrankungen

  2. Three-dimensional radiobiological dosimetry (3D-RD) with 124I PET for 131I therapy of thyroid cancer

    International Nuclear Information System (INIS)

    Radioiodine therapy of thyroid cancer was the first and remains among the most successful radiopharmaceutical (RPT) treatments of cancer although its clinical use is based on imprecise dosimetry. The positron emitting radioiodine, 124I, in combination with positron emission tomography (PET)/CT has made it possible to measure the spatial distribution of radioiodine in tumors and normal organs at high resolution and sensitivity. The CT component of PET/CT has made it simpler to match the activity distribution to the corresponding anatomy. These developments have facilitated patient-specific dosimetry (PSD), utilizing software packages such as three-dimensional radiobiological dosimetry (3D-RD), which can account for individual patient differences in pharmacokinetics and anatomy. We highlight specific examples of such calculations and discuss the potential impact of 124I PET/CT on thyroid cancer therapy. (orig.)

  3. A very thin havar film vacuum window for heavy ions to perform radiobiology studies at the BNL Tandem

    International Nuclear Information System (INIS)

    Heavy ion beams from the BNL Tandem Van de Graaff accelerators will be made available for radiobiology studies on cell cultures. Beam energy losses need to be minimized both in the vacuum window and in the air in order to achieve the ranges required for the cells to be studied. This is particularly challenging for ions heavier than iron. The design is presented of a 0.4-inch diameter Havar film window that will satisfy these requirements. Films as thin as 80 microinches were successfully pressure tested. The final thickness to be used may be slightly larger to help in achieving pin hole free windows. We discuss design considerations and present pressure and vacuum test results as well as tests with heavy ion beams.

  4. Radiobiological parameters of four glioblastoma compared to four other histological types of human tumor xenografts in nude mice

    International Nuclear Information System (INIS)

    Purpose/Objective: Glioblastoma Multiforme (GBM) is a highly malignant tumor of the central nervous system with aggressive biological behavior and a fatal clinical outcome. Several radiobiological parameters might contribute to these poor results. In this study, we investigated seventeen biological parameters of four GBM xenografts and compared the results with four other histological types of human tumor xenografts in nude mice. Methods and Materials: Most of the xenografts retained the individual histological features of their original tumor types. Four GBM xenografts (U87, HP555, MMC1 and HGL21), two squamous cell carcinomas (SCC21 and FaDu), one soft tissue sarcoma (STS26T), and colon cancer (HCT15) xenografts were used. The tumors were implanted in the hindleg of 5-6 Gy WBI nude mice. The following parameters were investigated for most of the xenografts: fractionated TCD50 (the dose of radiation which controls 50% of the tumors) using 30 fractions in 15 days. The parameters pO2, IFP (interstitial fluid pressure), Tpot, SF2 (plastic and Courtenay), PE (plating efficiency), D0, GSH, TCD50 single dose in oxic and hypoxic conditions, the rate of metastasis in SCID mice, VDT (volume doubling time), spontaneous apoptosis, induced apoptosis after 30 and 60 Gy and p53 over-expression. Results: Using the t-test, there was a significantly less spontaneous apoptosis in GBM xenografts when compared with the other histological types. However, no significant difference was found between both groups of xenografts in the remaining biological parameters investigated. Conclusion: These data demonstrate that, with the exception of spontaneous apoptosis, no significant difference was found in fifteen biological parameters between GBM xenografts and the other histological types implanted into the subcutaneous tissue of nude mice. The data suggests that the classical radiobiological parameters cannot explain the poor response of GBM to radiation. Supported by NCI Grant CA13311

  5. Arctic and Aleutian terns, Amchitka Island, Alaska

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Baird 1980 has recently reported on the ecology of Arctic terns Sterna paradisaea and Aleutian terns Sterna aleutica from 4 areas of mainland Alaska. However, prior...

  6. Proceedings of the international conference on radiation biology and clinical applications: a molecular approach towards innovations in applied radiobiology and a workshop on strategies in radiation research

    International Nuclear Information System (INIS)

    Innovations in radiotherapy approaches to cancer and radiation biology research is of growing interest in radiation researchers to conduct preclinical studies at their centers and translating the results as soon as possible to clinical radiotherapy practice. Recent papers have greatly enriched the current knowledge of radiation oncology, especially radiobiology and molecular oncology, and this has radically changed the oncology practice in radiation therapy in just a few years. The conference theme highlights the molecular and cellular responses within tissue and higher levels of mammalian biological organization. New experimental radiobiology research to underpin current and future regulatory decisions setting workplace exposure limits. To develop rapid, high-precision analytical methods that assess radiation exposure doses from clinical samples and thus aid in the triage and medical management of radiological casualties. Innovative approaches to improve the accuracy, dose range, ease of use, and speed of classical biodosimetry. Papers relevant to INIS are indexed separately

  7. Radiobiological and genetic effects of Bromus inermis seed progeny from populations of the East-Ural Radioactive Trace (Russia, Kyshtym accident) - Radiobiological and genetic effects for Bromus inermis Leyss. Populations at the East-Ural radioactive trace (Russia, Kyshtym accident in 1957)

    Energy Technology Data Exchange (ETDEWEB)

    Antonova, Elena V.; Pozolotna, Vera N. [Institute of Plant and Animal Ecology UB RAS, 8 Marta str. 202, 620144, Ekaterinburg (Russian Federation); Karimullina, Elina M. [Institute of Plant and Animal Ecology UB RAS, 8 Marta str. 202, 620144, Ekaterinburg (Russian Federation); Department of Developmental and Cell Biology, University of California, 2011 Biological Sciences III, Irvine, CA 92697-2300 (United States); Roeder, Marion S. [Leibniz Institute of Plant Genetics and Crop Plant Research, Corrensstrasse 3, D-06466, Gatersleben (Germany)

    2014-07-01

    This investigation dedicates the problem of remote consequences of radiation impact on plant populations. This is a part of a complex research, which includes the classic triad of radioecology (Timofeev-Ressovsky 1963): 'accumulation and migration of radionuclides in different components of ecosystems - assessment of radiation dose - investigation of radiobiological effects'. We used the populations of smooth brome (Bromus inermis Leyss.) as a model system for the investigation of radiobiological and genetic effects. It is radiosensitive plant (Preobrazhenskaya 1971). These species may be used as objects for bio-indication at the radioactive contaminated areas, and as well as large-scale radioecological studies, because the adaptation processes are faster for radiosensitive species (Shevchenko et al., 1992; Pozolotina et al. 2005). We calculated external and internal whole-body dose rates by ERICA Tool (Karimullina et al., 2013). The total dose rate for brome was under 100 mGy h{sup -1} at the most polluted site but 43-110 times (Tier 3) exceeded the background along the pollution gradient. Therefore it can be concluded that herbaceous plant populations currently exist under low level chronic exposure at the EURT area. During seven years we have studied variability of viability, mutability and radioresistance of brome seed progeny. The combined effects of radiation exposure and weather conductions at the EURT area were absent. It may be connect with wide variability of inter-population test parameters. At the same time the weather conductions had an influence on the quality of seed progeny at the background area. We analyzed also correlation between original viability and radioresistance of seed progeny from the all plots. This dependence was positive. It was shown negative dependence between original viability of seed progeny and low weight molecular antioxidants content too. Ionizing radiation is a mutagenic factor and, accordingly, elevated mutation

  8. Direct evaluation of radiobiological parameters from clinical data in the case of ion beam therapy: an alternative approach to the relative biological effectiveness

    International Nuclear Information System (INIS)

    The relative biological effectiveness (RBE) concept is commonly used in treatment planning for ion beam therapy. Whether models based on in vitro/in vivo RBE data can be used to predict human response to treatments is an open issue. In this work an alternative method, based on an effective radiobiological parameterization directly derived from clinical data, is presented. The method has been applied to the analysis of prostate cancer trials with protons and carbon ions. Prostate cancer trials with proton and carbon ion beams reporting 5 year-local control (LC5) and grade 2 (G2) or higher genitourinary toxicity rates (TOX) were selected from literature to test the method. Treatment simulations were performed on a representative subset of patients to produce dose and linear energy transfer distribution, which were used as explicative physical variables for the radiobiological modelling. Two models were taken into consideration: the microdosimetric kinetic model (MKM) and a linear model (LM). The radiobiological parameters of the LM and MKM were obtained by coupling them with the tumor control probability and normal tissue complication probability models to fit the LC5 and TOX data through likelihood maximization. The model ranking was based on the Akaike information criterion. Results showed large confidence intervals due to the limited variety of available treatment schedules. RBE values, such as RBE = 1.1 for protons in the treated volume, were derived as a by-product of the method, showing a consistency with current approaches. Carbon ion RBE values were also derived, showing lower values than those assumed for the original treatment planning in the target region, whereas higher values were found in the bladder. Most importantly, this work shows the possibility to infer the radiobiological parametrization for proton and carbon ion treatment directly from clinical data. (paper)

  9. Safety-Evaluation Report related to the renewal of the operating license for the research reactor at the Armed Forces Radiobiology Research Institute. Docket No. 50-170

    International Nuclear Information System (INIS)

    Supplement 1 to the Safety Evaluation Report related to the renewal of the operating license for the research reactor at the Armed Forces Radiobiology Research Institute has been prepared by the Office of Nuclear Reactor Regulation of the US Nuclear Regulatory Commission. The reactor facility is located in Montgomery County, Maryland. This supplement reports on the status of the licensee's emergency plan that had not been reviewed at the time the Safety Evaluation Report (NUREG-0882) was published

  10. SU-E-T-399: Determination of the Radiobiological Parameters That Describe the Dose-Response Relations of Xerostomia and Disgeusia From Head and Neck Radiotherapy

    International Nuclear Information System (INIS)

    Purpose: To estimate the radiobiological parameters that describe the doseresponse relations of xerostomia and disgeusia from head and neck cancer radiotherapy. To identify the organs that are best correlated with the manifestation of those clinical endpoints. Finally, to evaluate the goodnessof- fit by comparing the model predictions against the actual clinical results. Methods: In this study, 349 head and neck cancer patients were included. For each patient the dose volume histograms (DVH) of parotids (separate and combined), mandible, submandibular glands (separate and combined) and salivary glands were calculated. The follow-up of those patients was recorded at different times after the completion of the treatment (7 weeks, 3, 7, 12, 18 and 24 months). Acute and late xerostomia and acute disgeusia were the clinical endpoints examined. A maximum likelihood fitting was performed to calculate the best estimates of the parameters used by the relative seriality model. The statistical methods of the error distribution, the receiver operating characteristic (ROC) curve, the Pearson's test and the Akaike's information criterion were utilized to assess the goodness-of-fit and the agreement between the pattern of the radiobiological predictions with that of the clinical records. Results: The estimated values of the radiobiological parameters of salivary glands are D50 = 25.2 Gy, γ = 0.52, s = 0.001. The statistical analysis confirmed the clinical validity of those parameters (area under the ROC curve = 0.65 and AIC = 38.3). Conclusion: The analysis proved that the treatment outcome pattern of the patient material can be reproduced by the relative seriality model and the estimated radiobiological parameters. Salivary glands were found to have strong volume dependence (low relative seriality). Diminishing the biologically effective uniform dose to salivary glands below 30 Gy may significantly reduce the risk of complications to the patients irradiated for

  11. SU-E-T-399: Determination of the Radiobiological Parameters That Describe the Dose-Response Relations of Xerostomia and Disgeusia From Head and Neck Radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Mavroidis, P; Stathakis, S; Papanikolaou, N [University of Texas Health Science Center, UTHSCSA, San Antonio, TX (United States); Peixoto Xavier, C [University of Coimbra, Coimbra, Coimbra (Portugal); Costa Ferreira, B [University of Aveiro, Coimbra, Coimbra (Portugal); Khouri, L; Carmo Lopes, M do [IPOCFG, EPE, Coimbra, Coimbra (Portugal)

    2014-06-01

    Purpose: To estimate the radiobiological parameters that describe the doseresponse relations of xerostomia and disgeusia from head and neck cancer radiotherapy. To identify the organs that are best correlated with the manifestation of those clinical endpoints. Finally, to evaluate the goodnessof- fit by comparing the model predictions against the actual clinical results. Methods: In this study, 349 head and neck cancer patients were included. For each patient the dose volume histograms (DVH) of parotids (separate and combined), mandible, submandibular glands (separate and combined) and salivary glands were calculated. The follow-up of those patients was recorded at different times after the completion of the treatment (7 weeks, 3, 7, 12, 18 and 24 months). Acute and late xerostomia and acute disgeusia were the clinical endpoints examined. A maximum likelihood fitting was performed to calculate the best estimates of the parameters used by the relative seriality model. The statistical methods of the error distribution, the receiver operating characteristic (ROC) curve, the Pearson's test and the Akaike's information criterion were utilized to assess the goodness-of-fit and the agreement between the pattern of the radiobiological predictions with that of the clinical records. Results: The estimated values of the radiobiological parameters of salivary glands are D50 = 25.2 Gy, γ = 0.52, s = 0.001. The statistical analysis confirmed the clinical validity of those parameters (area under the ROC curve = 0.65 and AIC = 38.3). Conclusion: The analysis proved that the treatment outcome pattern of the patient material can be reproduced by the relative seriality model and the estimated radiobiological parameters. Salivary glands were found to have strong volume dependence (low relative seriality). Diminishing the biologically effective uniform dose to salivary glands below 30 Gy may significantly reduce the risk of complications to the patients irradiated for

  12. Radioembolization of hepatocarcinoma with 90Y glass microspheres: development of an individualized treatment planning strategy based on dosimetry and radiobiology

    International Nuclear Information System (INIS)

    The aim of this study was to optimize the dosimetric approach and to review the absorbed doses delivered, taking into account radiobiology, in order to identify the optimal methodology for an individualized treatment planning strategy based on 99mTc-macroaggregated albumin (MAA) single photon emission computed tomography (SPECT) images. We performed retrospective dosimetry of the standard TheraSphere registered treatment on 52 intermediate (n = 17) and advanced (i.e. portal vein thrombosis, n = 35) hepatocarcinoma patients with tumour burden < 50 % and without obstruction of the main portal vein trunk. Response was monitored with the densitometric radiological criterion (European Association for the Study of the Liver) and treatment-related liver decompensation was defined ad hoc with a time cut-off of 6 months. Adverse events clearly attributable to disease progression or other causes were not attributed to treatment. Voxel dosimetry was performed with the local deposition method on 99mTc-MAA SPECT images. The reconstruction protocol was optimized. Concordance of 99mTc-MAA and 90Y bremsstrahlung microsphere biodistributions was studied in 35 sequential patients. Two segmentation methods were used, based on SPECT alone (home-made code) or on coregistered SPECT/CT images (IMALYTICS trademark by Philips). STRATOS trademark absorbed dose calculation was validated for 90Y with a single time point. Radiobiology was used introducing other dosimetric variables besides the mean absorbed dose D: equivalent uniform dose (EUD), biologically effective dose averaged over voxel values (BEDave) and equivalent uniform biologically effective dose (EUBED). Two sets of radiobiological parameters, the first derived from microsphere irradiation and the second from external beam radiotherapy (EBRT), were used. A total of 16 possible methodologies were compared. Tumour control probability (TCP) and normal tissue complication probability (NTCP) were derived. The area under the curve (AUC

  13. Use of the NASA Space Radiation Laboratory at Brookhaven National Laboratory to Conduct Charged Particle Radiobiology Studies Relevant to Ion Therapy.

    Science.gov (United States)

    Held, Kathryn D; Blakely, Eleanor A; Story, Michael D; Lowenstein, Derek I

    2016-06-01

    Although clinical studies with carbon ions have been conducted successfully in Japan and Europe, the limited radiobiological information about charged particles that are heavier than protons remains a significant impediment to exploiting the full potential of particle therapy. There is growing interest in the U.S. to build a cancer treatment facility that utilizes charged particles heavier than protons. Therefore, it is essential that additional radiobiological knowledge be obtained using state-of-the-art technologies and biological models and end points relevant to clinical outcome. Currently, most such ion radiotherapy-related research is being conducted outside the U.S. This article addresses the substantial contributions to that research that are possible at the NASA Space Radiation Laboratory (NSRL) at Brookhaven National Laboratory (BNL), which is the only facility in the U.S. at this time where heavy-ion radiobiology research with the ion species and energies of interest for therapy can be done. Here, we briefly discuss the relevant facilities at NSRL and how selected charged particle biology research gaps could be addressed using those facilities. PMID:27195609

  14. Estimation of a Self-Consistent Set of Radiobiological Parameters From Hypofractionated Versus Standard Radiation Therapy of Prostate Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Pedicini, Piernicola, E-mail: ppiern@libero.it [Service of Medical Physics, Istituto di Ricovero e Cura a Carattere Scientifico Centro di Riferimento Oncologico della Basilicata, Rionero in Vulture (Italy); Strigari, Lidia [Laboratory of Medical Physics and Expert Systems, Istituto Nazionale Tumori Regina Elena, Rome (Italy); Benassi, Marcello [Service of Medical Physics, Istituto Scientifico Romagnolo per lo Studio e la Cura dei Tumori, Meldola (Italy)

    2013-04-01

    Purpose: To determine a self-consistent set of radiobiological parameters in prostate cancer. Methods and Materials: A method to estimate intrinsic radiosensitivity (α), fractionation sensitivity (α/β), repopulation doubling time, number of clonogens, and kick-off time for accelerated repopulation of prostate cancer has been developed. Based on the generalized linear-quadratic model and without assuming the isoeffective hypothesis, the potential applications of the method were investigated using the clinical outcome of biochemical relapse-free survival recently reviewed in the literature. The strengths and limitations of the method, regarding the fitted parameters and 95% confidence intervals (CIs), are also discussed. Results: Our best estimate of α/β is 2.96 Gy (95% CI 2.41-3.53 Gy). The corresponding α value is 0.16 Gy{sup −1} (95% CI 0.14-0.18 Gy{sup −1}), which is compatible with a realistic number of clonogens: 6.5 × 10{sup 6} (95% CI 1.5 × 10{sup 6}-2.1 × 10{sup 7}). The estimated cell doubling time is 5.1 days (95% CI 4.2-7.2 days), very low if compared with that reported in the literature. This corresponds to the dose required to offset the repopulation occurring in 1 day of 0.52 Gy/d (95% CI 0.32-0.68 Gy/d). However, a long kick-off time of 31 days (95% CI 22-41 days) from the start of radiation therapy was found. Conclusion: The proposed analytic/graphic method has allowed the fitting of clinical data, providing a self-consistent set of radiobiological parameters for prostate cancer. With our analysis we confirm a low value for α/β with a correspondingly high value of intrinsic radiosensitivity, a realistic average number of clonogens, a long kick-off time for accelerated repopulation, and a surprisingly fast repopulation that suggests the involvement of subpopulations of specifically tumorigenic stem cells during continuing radiation therapy.

  15. Weighting factors Q and WR for photon-, electron- and neutron radiations in their relationship with radiobiological and epidemiological source data

    International Nuclear Information System (INIS)

    For photon and electron radiations, radiobiological low-dose RBE values, with 250 kV X-rays as the reference radiation, can vary from 0.5 up to 3.5 in dependence upon mean LET. On the other hand epidemiological risk data for the sparsely ionizing radiations are subjected to considerable methodical limitations of accuracy, so that a trend with LET is not detectable. This justifies the strong simplification consisting in the recommendation of Q=1 and wR=1 for all sparsely ionizing radiations, and 250 kV X-rays have to be regarded as representative. In individual cases of radiation risk estimate, radiation quality dependent risk factors should however be employed as far as available even for the photon and electron radiations. The risk data obtained in the Hiroshima and Nagasaki Life Span Study are valid for a very wide photon spectrum whose mean LET value approximates that for 60Co gamma radiation. For neutron radiation with energies below 1 MeV (fission spectra) the low-dose radiobiological RBE values referred to 250 kV X-rays are found around 20, but vary from 30 to 80 when referred to 60Co gamma radiation. For reference radiation with strong curvature of the dose effect curves, there are however considerable methodical problems which limit the accuracy of initial slope determination. Since epidemiological risk factors for the neutron radiation are still lacking, experimental RBE values for tumor induction in laboratory animals have served instead as the data base for the recommendations of Q values up to 30 and neutron wR values up to 20. In comparing these with the constant setting of Q=1 and wR=1 for the manifold of photon and electron radiations, one should consider that this manifold is approximately represented by 250 kV X-rays. Accordingly, the system of Q and wR values corresponds to our present knowledge, but should also be seen in the light of the still existing methodical imperfection. (orig.)

  16. Estimation of a Self-Consistent Set of Radiobiological Parameters From Hypofractionated Versus Standard Radiation Therapy of Prostate Cancer

    International Nuclear Information System (INIS)

    Purpose: To determine a self-consistent set of radiobiological parameters in prostate cancer. Methods and Materials: A method to estimate intrinsic radiosensitivity (α), fractionation sensitivity (α/β), repopulation doubling time, number of clonogens, and kick-off time for accelerated repopulation of prostate cancer has been developed. Based on the generalized linear-quadratic model and without assuming the isoeffective hypothesis, the potential applications of the method were investigated using the clinical outcome of biochemical relapse-free survival recently reviewed in the literature. The strengths and limitations of the method, regarding the fitted parameters and 95% confidence intervals (CIs), are also discussed. Results: Our best estimate of α/β is 2.96 Gy (95% CI 2.41-3.53 Gy). The corresponding α value is 0.16 Gy−1 (95% CI 0.14-0.18 Gy−1), which is compatible with a realistic number of clonogens: 6.5 × 106 (95% CI 1.5 × 106-2.1 × 107). The estimated cell doubling time is 5.1 days (95% CI 4.2-7.2 days), very low if compared with that reported in the literature. This corresponds to the dose required to offset the repopulation occurring in 1 day of 0.52 Gy/d (95% CI 0.32-0.68 Gy/d). However, a long kick-off time of 31 days (95% CI 22-41 days) from the start of radiation therapy was found. Conclusion: The proposed analytic/graphic method has allowed the fitting of clinical data, providing a self-consistent set of radiobiological parameters for prostate cancer. With our analysis we confirm a low value for α/β with a correspondingly high value of intrinsic radiosensitivity, a realistic average number of clonogens, a long kick-off time for accelerated repopulation, and a surprisingly fast repopulation that suggests the involvement of subpopulations of specifically tumorigenic stem cells during continuing radiation therapy

  17. Radiobiological responses for two cell lines following continuous low dose-rate (CLDR) and pulsed dose rate (PDR) brachytherapy

    International Nuclear Information System (INIS)

    The iso-effective irradiation of continuous low-dose-rate (CLDR) irradiation was compared with that of various schedules of pulsed dose rate (PDR) irradiation for cells of two established human lines, T-47D and NHIK 3025. Complete single-dose response curves were obtained for determination of parameters α and β by fitting of the linear quadratic formula. Sublethal damage repair constants μ and T1/2 were determined by split-dose recovery experiments. On basis of the acquired parameters of each cell type the relative effectiveness of the two regimens of irradiation (CLDR and PDR) was calculated by use of Fowler's radiobiological model for iso-effect irradiation for repeated fractions of dose delivered at medium dose rates. For both cell types the predicted and observed relative effectiveness was compared at low and high iso-effect levels. The results indicate that the effect of PDR irradiation predicted by Fowler's model is equal to that of CLDR irradiation for both small and large doses with T-47D cells. With NHIK 3025 cells PDR irradiation induces a larger effect than predicted by the model for small doses, while it induces the predicted effect for high doses. The underlying cause of this difference is unclear, but cell-cycle parameters, like G2-accumulation is tested and found to be the same for the two cell lines

  18. Current (1984) status of the study of 226Ra and 228Ra in humans at the Center for Human Radiobiology

    International Nuclear Information System (INIS)

    The Center for Human Radiobiology has identified 5784 persons by name and type of exposure to 226Ra and 228Ra. Included are 4863 dial painters (mostly women) and non-laboratory employees of the radium dial industry, 410 laboratory workers, 399 persons who received radium for supposed therapeutic effects, and 112 in other categories. Body contents of radium have been measured in 1916 of the dial workers and about one-half of the subjects in the other groups. Bone sarcomas, carcinomas of the paranasal sinuses and mastoids, and deterioration of skeletal tissue are still the only effects unequivocally attributable to internal radium. Excess leukemias have not been observed and other malignancies, if in excess, appear more likely to be related to external gamma radiation or radon than to internal radium. Positive correlations with radium burdens have been found for the incidence of benign exostoses among subjects exposed to radium before age 18 and for shortened latency of ocular cataracts. 27 references, 3 figures, 5 tables

  19. A radiobiology-based inverse treatment planning method for optimisation of permanent l-125 prostate implants in focal brachytherapy

    Science.gov (United States)

    Haworth, Annette; Mears, Christopher; Betts, John M.; Reynolds, Hayley M.; Tack, Guido; Leo, Kevin; Williams, Scott; Ebert, Martin A.

    2016-01-01

    Treatment plans for ten patients, initially treated with a conventional approach to low dose-rate brachytherapy (LDR, 145 Gy to entire prostate), were compared with plans for the same patients created with an inverse-optimisation planning process utilising a biologically-based objective. The ‘biological optimisation’ considered a non-uniform distribution of tumour cell density through the prostate based on known and expected locations of the tumour. Using dose planning-objectives derived from our previous biological-model validation study, the volume of the urethra receiving 125% of the conventional prescription (145 Gy) was reduced from a median value of 64% to less than 8% whilst maintaining high values of TCP. On average, the number of planned seeds was reduced from 85 to less than 75. The robustness of plans to random seed displacements needs to be carefully considered when using contemporary seed placement techniques. We conclude that an inverse planning approach to LDR treatments, based on a biological objective, has the potential to maintain high rates of tumour control whilst minimising dose to healthy tissue. In future, the radiobiological model will be informed using multi-parametric MRI to provide a personalised medicine approach.

  20. AAPM protocol for 40-300 kV x-ray beam dosimetry in radiotherapy and radiobiology

    International Nuclear Information System (INIS)

    The American Association of Physicists in Medicine (AAPM) presents a new protocol, developed by the Radiation Therapy Committee Task Group 61, for reference dosimetry of low- and medium-energy x rays for radiotherapy and radiobiology (40 kV≤tube potential≤300 kV). It is based on ionization chambers calibrated in air in terms of air kerma. If the point of interest is at or close to the surface, one unified approach over the entire energy range shall be used to determine absorbed dose to water at the surface of a water phantom based on an in-air measurement (the 'in-air' method). If the point of interest is at a depth, an in-water measurement at a depth of 2 cm shall be used for tube potentials ≥100 kV (the 'in-phantom' method). The in-phantom method is not recommended for tube potentials <100 kV. Guidelines are provided to determine the dose at other points in water and the dose at the surface of other biological materials of interest. The protocol is based on an up-to-date data set of basic dosimetry parameters, which produce consistent dose values for the two methods recommended. Estimates of uncertainties on the final dose values are also presented

  1. Feasibility study on the use of polyallyldiglycol-carbonate cell dishes in TUNEL assay for alpha particle radiobiological experiments

    Science.gov (United States)

    Chan, K. F.; Yum, E. H. W.; Wan, C. K.; Fong, W. F.; Yu, K. N.

    2007-08-01

    In the present work, we have studied the feasibility of a method based on polyallyldiglycol-carbonate (PADC) films to investigate the effects of alpha particles on HeLa cervix cancer cells. Thin PADC films with thickness of about 20 μm were prepared from commercially available CR-39 films by chemical etching to fabricate custom-made petri dishes for cell culture, which could accurately record alpha particle hit positions. A special method involving "base tracks" for aligning the images of cell nuclei and alpha particle hits has been proposed, so that alpha particle transversals of cell nuclei can be visually counted. Radiobiological experiments were carried out to induce DNA damages, with the TdT-mediated d UTP Nick- End Labeling (TUNEL) fluorescence method employed to detect DNA strand breaks. The staining results were investigated by flow cytometer. The preliminary results showed that more strand breaks occurred in cells hit by alpha particles with lower energies. Moreover, large TUNEL positive signals were obtained even with small percentages of cells irradiated and TUNEL signals were also obtained from non-targeted cells. These provided evidence for the bystander effect.

  2. Feasibility study on the use of polyallyldiglycol-carbonate cell dishes in TUNEL assay for alpha particle radiobiological experiments

    Energy Technology Data Exchange (ETDEWEB)

    Chan, K.F. [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong, Hong Kong (China); Yum, E.H.W. [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong, Hong Kong (China); Wan, C.K. [Department of Biology and Chemistry, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong, Hong Kong (China); Fong, W.F. [Research and Development Division, School of Chinese Medicine, Hong Kong Baptist University, Baptist University Road, Kowloon Tong, Hong Kong (China); Yu, K.N. [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong, Hong Kong (China)]. E-mail: peter.yu@cityu.edu.hk

    2007-08-15

    In the present work, we have studied the feasibility of a method based on polyallyldiglycol-carbonate (PADC) films to investigate the effects of alpha particles on HeLa cervix cancer cells. Thin PADC films with thickness of about 20 {mu}m were prepared from commercially available CR-39 films by chemical etching to fabricate custom-made petri dishes for cell culture, which could accurately record alpha particle hit positions. A special method involving 'base tracks' for aligning the images of cell nuclei and alpha particle hits has been proposed, so that alpha particle transversals of cell nuclei can be visually counted. Radiobiological experiments were carried out to induce DNA damages, with the TdT-mediated dUTP Nick-End Labeling (TUNEL) fluorescence method employed to detect DNA strand breaks. The staining results were investigated by flow cytometer. The preliminary results showed that more strand breaks occurred in cells hit by alpha particles with lower energies. Moreover, large TUNEL positive signals were obtained even with small percentages of cells irradiated and TUNEL signals were also obtained from non-targeted cells. These provided evidence for the bystander effect.

  3. Monte Carlo application based on GEANT4 toolkit to simulate a laser–plasma electron beam line for radiobiological studies

    Energy Technology Data Exchange (ETDEWEB)

    Lamia, D., E-mail: debora.lamia@ibfm.cnr.it [Institute of Molecular Bioimaging and Physiology IBFM CNR – LATO, Cefalù (Italy); Russo, G., E-mail: giorgio.russo@ibfm.cnr.it [Institute of Molecular Bioimaging and Physiology IBFM CNR – LATO, Cefalù (Italy); Casarino, C.; Gagliano, L.; Candiano, G.C. [Institute of Molecular Bioimaging and Physiology IBFM CNR – LATO, Cefalù (Italy); Labate, L. [Intense Laser Irradiation Laboratory (ILIL) – National Institute of Optics INO CNR, Pisa (Italy); National Institute for Nuclear Physics INFN, Pisa Section and Frascati National Laboratories LNF (Italy); Baffigi, F.; Fulgentini, L.; Giulietti, A.; Koester, P.; Palla, D. [Intense Laser Irradiation Laboratory (ILIL) – National Institute of Optics INO CNR, Pisa (Italy); Gizzi, L.A. [Intense Laser Irradiation Laboratory (ILIL) – National Institute of Optics INO CNR, Pisa (Italy); National Institute for Nuclear Physics INFN, Pisa Section and Frascati National Laboratories LNF (Italy); Gilardi, M.C. [Institute of Molecular Bioimaging and Physiology IBFM CNR, Segrate (Italy); University of Milano-Bicocca, Milano (Italy)

    2015-06-21

    We report on the development of a Monte Carlo application, based on the GEANT4 toolkit, for the characterization and optimization of electron beams for clinical applications produced by a laser-driven plasma source. The GEANT4 application is conceived so as to represent in the most general way the physical and geometrical features of a typical laser-driven accelerator. It is designed to provide standard dosimetric figures such as percentage dose depth curves, two-dimensional dose distributions and 3D dose profiles at different positions both inside and outside the interaction chamber. The application was validated by comparing its predictions to experimental measurements carried out on a real laser-driven accelerator. The work is aimed at optimizing the source, by using this novel application, for radiobiological studies and, in perspective, for medical applications. - Highlights: • Development of a Monte Carlo application based on GEANT4 toolkit. • Experimental measurements carried out with a laser-driven acceleration system. • Validation of Geant4 application comparing experimental data with the simulated ones. • Dosimetric characterization of the acceleration system.

  4. Monte Carlo application based on GEANT4 toolkit to simulate a laser–plasma electron beam line for radiobiological studies

    International Nuclear Information System (INIS)

    We report on the development of a Monte Carlo application, based on the GEANT4 toolkit, for the characterization and optimization of electron beams for clinical applications produced by a laser-driven plasma source. The GEANT4 application is conceived so as to represent in the most general way the physical and geometrical features of a typical laser-driven accelerator. It is designed to provide standard dosimetric figures such as percentage dose depth curves, two-dimensional dose distributions and 3D dose profiles at different positions both inside and outside the interaction chamber. The application was validated by comparing its predictions to experimental measurements carried out on a real laser-driven accelerator. The work is aimed at optimizing the source, by using this novel application, for radiobiological studies and, in perspective, for medical applications. - Highlights: • Development of a Monte Carlo application based on GEANT4 toolkit. • Experimental measurements carried out with a laser-driven acceleration system. • Validation of Geant4 application comparing experimental data with the simulated ones. • Dosimetric characterization of the acceleration system

  5. Current (1984) status of the study of 226Ra and 228Ra in humans at the Center for Human Radiobiology

    International Nuclear Information System (INIS)

    The Center for Human Radiobiology has identified 5784 persons by name and type of exposure to 226Ra and 228Ra. Included are 4863 dial painters (mostly women) and non-laboratory employees of the radium dial industry, 410 laboratory workers, 399 persons who received radium for supposed therapeutic effects, and 112 in other categories. Body contents of radium have been measured in 1916 of the dial workers and about one-half of the subjects in the other groups. Bone sarcomas, carcinomas of the paranasal sinuses and mastoids, and deterioration of skeletal tissue are still the only effects unequivocally attributable to internal radium. Excess leukemias have not been observed and other malignancies, if in excess, appear more likely to be related to external gamma radiation or radon than to internal radium. Positive correlations with radium burdens have been found for the incidence of benign exostoses among subjects exposed to radium before age 18 and for shortened latency of ocular cataracts. 26 references, 3 figures, 5 tables

  6. Radiobiological analysis of region with higher radiation background. The effect of the background on the isomorphism of some enzymes

    International Nuclear Information System (INIS)

    An attempt is made to establish the the time when the prolong impact of slightly increased radiation background get over the compensator mechanisms of living systems. The object of investigation was the ecosystem of the Bay of Wromos (Black Sea, BG) and its surroundings where the flotation slack from an uranium mine was disposed. radioactivity. The following radiobiological picture of the site is obtained according to measurements performed: the alpha-activity of the beach sands is higher than one of the slack and is different in plants; the beta-activity is higher compared to controls in all samples investigated; the gamma spectra show high concentration of the members of U-238 and Th-232 series. The biological effect provoked by this heightened radiation background is studied by means of the isoenzymes as indicators of changes on molecular level. The isoenzyme spectra of lactate dehydrogenase and butyrol dehydrogenase is studied by vertical electrophoresis. The following species are tested: Tettigonia candata charp, Galliptumus italicus, Grillus campestris and Lumbicus terrestrial. An increase in activity and quantity of enzymes as well as changes of their isoenzyme spectra is observed. Calliptumus italicus could be used as a bio indicator of contamination, as it show better separation of the LDH and BDH-isoforms of LDH and BDH, and is more wide-spread. The increase in activity and quantity of some isoenzyme fractions in the conditions of this experiment is one of the possible mechanisms for increase in radioresistance of the living systems. 3 tabs., 2 figs., 8 refs

  7. Radiobiological long-term accumulation of environmental alpha radioactivity in extracted human teeth and animal bones in Malaysia

    International Nuclear Information System (INIS)

    In this study, the radiobiological analysis of natural alpha emitters in extracted human teeth and animal bones from Malaysia was estimated. The microdistributions of alpha particles in tooth and bone samples were measured using CR-39 alpha-particle track detectors. The lowest and highest alpha emission rates in teeth in the Kedah and Perak states were 0.0080 ± 0.0005 mBq cm−2 and 0.061 ± 0.008 mBq cm−2, whereas those of bones in the Perlis and Kedah states were 0.0140 ± 0.0001 mBq cm−2 and 0.7700 ± 0.0282 mBq cm−2, respectively. The average alpha emission rate in male teeth was 0.0209 ± 0.0008 mBq cm−2, whereas that of female teeth was 0.0199 ± 0.0010 mBq cm−2. The alpha emission rate in teeth is higher in smokers (0.0228 ± 0.0008 mBq cm−2) than in non-smokers (0.0179 ± 0.0008 mBq cm−2). Such difference was found statistically significant (p < 0.01). - Highlights: • Alpha emission rates in teeth from smokers slightly higher than non-smokers. • Difference between alpha rates in male and female tooth not statistically significant. • Alpha particles have the same effect at any age. • Difference between alpha rates in bones was statistically significant

  8. Excel programs estimating tissue tolerance of irradiation based on LQ model

    International Nuclear Information System (INIS)

    The programs have been written on a point of view of a medical physicist in radiotherapy and not a reacher in radiobiology. Using the Linear-Quadratic (LQ) model based on the interactive Excel system the authors have been tried to obtain suggestions for the irradiation parameters for equivalent treatment schemes using data of radiobiology. The authors strongly advise do not use this results on the patients.The program can be used to compare different schemes of irradiation or as well as to verify if an imagined scheme is to be follow or not. As concern the LQ model itself, there are two parameters (α/β and T 1/2) that still remain to be specified more exactly and more 'personalized' for each tissue taken into account as well as to be completed with time parameter

  9. Radiobiological risk estimates of adverse events and secondary cancer for proton and photon radiation therapy of pediatric medulloblastoma

    Energy Technology Data Exchange (ETDEWEB)

    Brodin, N. Patrik (Radiation Medicine Research Center, Dept. of Radiation Oncology, Rigshospitalet, Univ. of Copenhagen (Denmark); Niels Bohr Inst., Faculty of Sciences, Univ. of Copenhagen (Denmark)), e-mail: brodin.patrik@gmail.com; Munck af Rosenschoeld, Per; Aznar, Marianne C.; Vogelius, Ivan R. (Radiation Medicine Research Center, Dept. of Radiation Oncology, Rigshospitalet, Univ. of Copenhagen (Denmark)); Kiil-Berthelsen, Anne (Radiation Medicine Research Center, Dept. of Radiation Oncology, Rigshospitalet, Univ. of Copenhagen (Denmark); Dept. of Clinical Physiology and Nuclear Medicine, Centre of Diagnostic Investigations, Rigshospitalet, Univ. of Copenhagen (Denmark)); Nilsson, Per; Bjoerk-Eriksson, Thomas (Dept. of Oncology, Skaane Univ. Hospital and Lund Univ., Lund (Sweden)); Lannering, Birgitta (Dept. of Paediatric Oncology, The Queen Silvia Children' s Hospital, Gothenburg (Sweden))

    2011-08-15

    Introduction. The aim of this model study was to estimate and compare the risk of radiation-induced adverse late effects in pediatric patients with medulloblastoma (MB) treated with either three-dimensional conformal radiotherapy (3D CRT), inversely-optimized arc therapy (RapidArc (RA)) or spot-scanned intensity-modulated proton therapy (IMPT). The aim was also to find dose-volume toxicity parameters relevant to children undergoing RT to be used in the inverse planning of RA and IMPT, and to use in the risk estimations. Material and methods. Treatment plans were created for all three techniques on 10 pediatric patients that have been treated with craniospinal irradiation (CSI) at our institution in 2007-2009. Plans were generated for two prescription CSI doses, 23.4 Gy and 36 Gy. Risk estimates were based on childhood cancer survivor data when available and secondary cancer (SC) risks were estimated as a function of age at exposure and attained age according to the organ-equivalent dose (OED) concept. Results. Estimates of SC risk was higher for the RA plans and differentiable from the estimates for 3D CRT at attained ages above 40 years. The risk of developing heart failure, hearing loss, hypothyroidism and xerostomia was highest for the 3D CRT plans. The risks of all adverse effects were estimated as lowest for the IMPT plans, even when including secondary neutron (SN) irradiation with high values of the neutron radiation weighting factors (WR{sub neutron}). Conclusions. When comparing RA and 3D CRT treatment for pediatric MB it is a matter of comparing higher SC risk against higher risks of non-cancer adverse events. Considering time until onset of the different complications is necessary to fully assess patient benefit in such a comparison. The IMPT plans, including SN dose contribution, compared favorably to the photon techniques in terms of all radiobiological risk estimates

  10. In vitro and in vivo studies on radiobiological effects of prolonged fraction delivery time in A549 cells.

    Science.gov (United States)

    Jiang, Ling; Xiong, Xiao-Peng; Hu, Chao-Su; Ou, Zhou-Luo; Zhu, Guo-Pei; Ying, Hong-Mei

    2013-03-01

    Intensity-modulated radiation therapy, when used in the clinic, prolongs fraction delivery time. Here we investigated both the in vivoand in vitroradiobiological effects on the A549 cell line, including the effect of different delivery times with the same dose on A549 tumor growth in nude mice. The in vitroeffects were studied with clonogenic assays, using linear-quadratic and incomplete repair models to fit the dose-survival curves. Fractionated irradiation of different doses was given at one fraction per day, simulating a clinical dose-time-fractionation pattern. The longer the interval between the exposures, the more cells survived. To investigate the in vivoeffect, we used sixty-four nude mice implanted with A549 cells in the back legs, randomly assigned into eight groups. A 15 Gy radiation dose was divided into different subfractions. The maximum and minimum tumor diameters were recorded to determine tumor growth. Tumor growth was delayed for groups with prolonged delivery time (40 min) compared to the group receiving a single dose of 15 Gy (P< 0.05), and tumors with a 20 min delivery time had delayed growth compared to those with a 40 min delivery time [20' (7.5 Gy × 2 F) vs 40' (7.5 Gy × 2 F), P= 0.035; 20' (3 Gy × 5 F) vs 40' (3 Gy × 5 F); P= 0.054; 20' (1.67 Gy × 9 F) vs 40' (1.67 Gy × 9 F), P= 0.028]. A prolonged delivery time decreased the radiobiological effects, so we strongly recommend keeping the delivery time as short as possible. PMID:23090953

  11. Cloned human bone marrow stromal lines demonstrate varied radiobiologic properties with respect to x-ray survival in vitro

    International Nuclear Information System (INIS)

    Fresh cultures of uncloned human bone marrow adherent stromal cells demonstrate increased radiation resistance at low dose rate (5cGy/min), D/sub o/ 146 cGy, n bar 2.0, compared to 200 cGy/min, D/sub o/ 99, n bar 1.03). (rho<0.05). Permanent clonal bone marrow stromal lines derived from human bone marrow stroma are designated KM101 and KM102. The irradiation survival curves of these cell lines at 5 cGy/min and 200 cGy/min were tested in vitro. Cell line KM102 demonstrated a D/sub o/ of 104 cGy and an extrapolation number of 1.9 at 200 cGy/min. At 5 cGy/min, the D/sub o/ was 211 cGy and the extrapolation number was 1.7. The D/sub o/ was significantly decreased at 200 cGy/min (rho<0.05). In contrast, cell line KM101 demonstrated a D/sub o/ of 165 cGy and an n bar of 1.5 cGy/min and this was not significantly altered at higher dose rate, with D/sub o/ of 156 cGy and extrapolation number of 1.4 at 200 rad/min. All cell lines at each target point were negative for Factor VIII, alkaline phosphatase, nonspecific esterase, lysozyme, and markers for T and B lymphocytes, and were positive for fibronectin, confirming their fibroblast reticular cell origin. These data indicate significant radiobiologic differences between stromal lines derived from the same human marrow in vitro

  12. Research trends in radiobiology since 40 years. a new approach: the enzymatic repair function of DNA, internal factor in evolution of biological systems under irradiation

    International Nuclear Information System (INIS)

    In the first part of the report, the author attempts to draw an historical scheme of successive research working hypotheses in radiobiology since 1924. Less than a generation ago the effect of radiation exposure were viewed as being direct, immediate, irreparable and unmodifiable. Now it is generally accepted that radiation lesion can also be indirect, delayed, reparable and often modified with appropriate chemical or biochemical treatment. It was however in 1962-1964 that came the decisive breakthrough in radiobiology with the discovery that the cell possesses a natural active self-defense mechanism against whatever stress would affect the integrity of the genetic message contained in the DNA structure itself. The existence of what could be considered as a fourth DNA function i.e. self-repair by enzymatic action under genetic control-brings at least to radiobiology the missing molecular biology basis it needed to get out of its 'phenomenological night' after abandon of the generalization of Lea's theory through lack of experimental evidence. In the second part, which is a prospective one, the author tries to set an enlarged synthesis considering the possible role of DNA repair system not only in cell survival - in presence or absence of dose modifiers or mutagens - but also in the artificial and natural evolution of biological system exposed to sub-lethal doses of radiation. Most recent data from the literature fit well with what must be still considered as a general working hypothesis. Studies dealing with phenotypic and genotypic characters linked with the acquisition of gamma and UV radiation resistance in 'Escherichia coli K12' has been started by the author, in collaboration with O. Tremeau, in order to bring a new experimental contribution in this respect. (author)

  13. The radiogram including CT, nuclear medicine, ultrasonography, NMR imaging, thermography, digital radiography, radiobiology, radiation protection, the revised X-Ray Ordinance. 3. rev. ed.

    International Nuclear Information System (INIS)

    After chapters dealing with radiation physics, with the equipment and all technical aspects, the book presents a full survey of radiographic methods and examination techniques, one complete chapter discusses the mammography in particular, whereas the following chapters deal with CT, contrast media, ultrasonography, NMR imaging, and nuclear medical diagnostics. Dosimetry, radiobiology and radiation exposure of man, radiation protection and the relevant legal provisions, - the X-Ray Ordinance and the Ordinance on Protection Against Harmful Effects of Ionizing Radiation -, as well as medical aspects of radiation effects are the subjects of the last chapters. (MG) With 170 figs., 43 tabs

  14. The Radiobiological Basis for Improvements in Radiotherapy and Low Dose Risk Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Hei, Tom K

    2009-12-09

    Overall Goal: This conference grant was proposed to organize and host an international conference at Columbia University in New York to critically assess the cellular and molecular signaling events and tissue response following radiation damage. The conference would also serve as a venue to play tribute to the more than forty years contributions made by Professor Eric J. Hall to the radiation biology field. The goals of the meeting were to examine tumor hypoxia and sensitizer development; recent advances made in clinical radiotherapy; addressed several low dose phenomena, including genomic instability and bystander effects that are important in radiation risk assessment. Study and Results: The symposium was held on October 13th and 14th, 2008 at the Alfred Lerner Hall in the Morningside campus of Columbia University. The symposium, entitled “From Beans to Genes: A Forty Year Odyssey in Radiation Biology” was attended by more than 120 faculty, scientists, clinicians, fellows and students. The symposium, spanned over a day and a half, covered four scientific themes. These included tumor hypoxia and radiosensitizers; low dose radiation response; radiation biology in the practice of radiotherapy, and radiation hazard in space and genetic predisposition to cancer. The program of the symposium is as follow:

  15. Development of a tool computer to compensate for interruptions of treatment and radiobiological comparisons Tr in external radiotherapy; Desarrollo de una herramienta informatica para la compensacion de interrupciones de tratamiento y comparaciones radiobiologicas en radioterapia externa

    Energy Technology Data Exchange (ETDEWEB)

    Ramos Pacho, J. A.; Sena Espinel, E.; Verde Velasco, J. M.; Garcia Repiso, S.; Perez Alvarez, M. E.; Delgado Apaaricio, J. M.; Martin Rincon, C.; Saez Beltran, M.; Gomez Gonzalez, N.; Cons Perez, N.

    2013-07-01

    Outages unscheduled in the course of external beam radiation treatments, and the loss of probability of tumour control (TCP), which make it necessary to have a tool that allows the adjustment of the compensation of the absorbed dose required to keep the biological effect on the tumor, controlling the possible impact on the organ at risk. In order to perform this radiobiological quickly setting has been developed a software application that also allows comparison of treatments with different subdivisions from the point of view of radiobiological. (Author)

  16. Consequences of anorectal cancer atlas implementation in the cooperative group setting: Radiobiologic analysis of a prospective randomized in silico target delineation study

    International Nuclear Information System (INIS)

    Purpose: The aim of this study is to ascertain the subsequent radiobiological impact of using a consensus guideline target volume delineation atlas. Materials and methods: Using a representative case and target volume delineation instructions derived from a proposed IMRT rectal cancer clinical trial, gross tumor volume (GTV) and clinical/planning target volumes (CTV/PTV) were contoured by 13 physician observers (Phase 1). The observers were then randomly assigned to follow (atlas) or not-follow (control) a consensus guideline/atlas for anorectal cancers, and instructed to re-contour the same case (Phase 2). Results: The atlas group was found to have increased tumor control probability (TCP) after the atlas intervention for both the CTV (p < 0.0001) and PTV1 (p = 0.0011) with decreasing normal tissue complication probability (NTCP) for small intestine, while the control group did not. Additionally, the atlas group had reduced variance in TCP for all target volumes and reduced variance in NTCP for the bowel. In Phase 2, the atlas group had increased TCP relative to the control for CTV (p = 0.03). Conclusions: Visual atlas and consensus treatment guideline usage in the development of rectal cancer IMRT treatment plans reduced the inter-observer radiobiological variation, with clinically relevant TCP alteration for CTV and PTV volumes

  17. Transformation of Physical DVHs to Radiobiologically Equivalent Ones in Hypofractionated Radiotherapy Analyzing Dosimetric and Clinical Parameters: A Practical Approach for Routine Clinical Practice in Radiation Oncology

    Directory of Open Access Journals (Sweden)

    Zoi Thrapsanioti

    2013-01-01

    Full Text Available Purpose. The purpose of this study was to transform DVHs from physical to radiobiological ones as well as to evaluate their reliability by correlations of dosimetric and clinical parameters for 50 patients with prostate cancer and 50 patients with breast cancer, who were submitted to Hypofractionated Radiotherapy. Methods and Materials. To achieve this transformation, we used both the linear-quadratic model (LQ model and the Niemierko model. The outcome of radiobiological DVHs was correlated with acute toxicity score according to EORTC/RTOG criteria. Results. Concerning the prostate radiotherapy, there was a significant correlation between RTOG acute rectal toxicity and ( and ( dosimetric parameters, calculated for  Gy. Moreover, concerning the breast radiotherapy there was a significant correlation between RTOG skin toxicity and dosimetric parameter, calculated for both  Gy ( and  Gy (. The new tool seems reliable and user-friendly. Conclusions. Our proposed model seems user-friendly. Its reliability in terms of agreement with the presented acute radiation induced toxicity was satisfactory. However, more patients are needed to extract safe conclusions.

  18. Radiobiology for eye plaque brachytherapy and evaluation of implant duration and radionuclide choice using an objective function

    Energy Technology Data Exchange (ETDEWEB)

    Gagne, Nolan L.; Leonard, Kara L.; Rivard, Mark J. [Department of Radiation Oncology, Tufts University School of Medicine, Boston, Massachusetts 02111 (United States)

    2012-06-15

    %-35% BED benefit over {sup 125}I, whereas {sup 131}Cs produced a 3%-7% BED detriment, independent of P, T, and plaque size. Additionally, corresponding organ at risk physical doses were lowest using {sup 103}Pd in all circumstances. Conclusions: The results suggest that shorter implant durations may correlate with more favorable outcomes compared to 7 day implants when treating small or medium intraocular lesions. The data also indicate that implant duration may be safely reduced if the prescription physical dose is likewise diminished and that {sup 103}Pd offers a substantial radiobiological benefit over {sup 125}I and {sup 131}Cs irrespective of plaque position, implant duration, and tumor size.

  19. Radiobiological Characterization of Two Photon-Beam Energies 6 and 15 MV used in Radiotherapy From Linear Accelerator

    International Nuclear Information System (INIS)

    The main objective of this study is to perform radiobiological characterization of two different photon beam energies, 6 MV and 15 MV, from linear accelerator used in radiotherapy, with special regard to late effects of radiation. Two end-points, namely cell survival and micronucleus induction were used for the characterization. Chinese hamster V 79 lung fibroblast cell line to prepare cell culture and to perform the innervate experiments. chromosomes number was counted and found to be 22 chromosomes per cell, this result is in complete agreement with expected 11 pairs of chromosomes representing the genome of this species. Cells were kept in confluent growth for two days and then exposed to two photon beam energies, 6 and 15 MV respectively. Different dose rates were used for the two beam energies, 0.25, 0.5, 1.0, 2.0, 4.0, 7.0 Gy. Cells were counted immediately after irradiation and re seeded, the seeded number of cells was calculated to the dose rate used. Another set of unirradiated cells treated the same as the experimental set was used as a control group. The plating efficiency (PE) was calculated for the control group, then cells were incubated at 37oC for 6 days to construct the survival curve, five samples were counted per dose and the mean was calculated. The two survival curves are similar for photon beam energies (6 and 15 MV) and the surviving fraction was decreased with dose rate. The two curves showed similar values of α and β parameters, this result is expected for the same radiation type (X-ray). For the micronuclei assay three samples for each dose were seeded and incubated at 37oC for 24 hours then Cytochalasin-B was added to block cells in cytokinesis phase of the mitosis. The micronuclei number was counted and plotted with dose. A significant positive correlation was found between dose and micronuclei frequency (P=0.00), moreover, the micronuclei frequency is relatively higher with 15 MV compared with 6 MV energy. This indicates the presence

  20. Problems modern radiobiology in valeilogy and ecology aspects of regions Caucasus

    International Nuclear Information System (INIS)

    of soiling East sea sides Black moore were high. This was defined as a width location of the sources an radionuclides, so and geophysical particularities of regions Caucasus. Power of dose a gamma-irradiating, with the first may 1986 y, maximum for central regions of South Caucasus reach 4-8 mays 1986 y. Additional (to background radiating) dose a gamma-irradiating a population s. Tbilisi herewith has formed s.Tbilisi after the damage on Chernobyl during has formed near 380 m d 300 micro Sv; maximum gobble dose external beta-irradiating a population k Gr, but average annual individual equivalent dose external gamma-irradiating same region reach only 300 micro Sv that forms the whole near 25% annual dose of background external irradiation. However, with provision for on the order of greater contamination levels on the seaside Black sea and in some regions of Caucasus these evaluations gave a ground for certain anxieties. Evaluations of doses of irradiating an organism of adult and teenagers inhalation and peroral fetters, on the direct to measurements the isotopes of iodine (children: inhalation 0,15, peroral - 21,1 milli Sv; adult: inhalation - 0,11, peroral -1,81 milli Sv) show levels comparable with evaluations United Nations Scientific Committee on the Effects of Atomic Radiation ( Official Records of the General Assembly ) in the report 1988 even for 'the most damaged' Bulgaria, Greece and e.a.. This points is to need of unwinding of special program to rehabilitations Caucasus. Brought consolidated tables on the evaluation of values 'redoubling dose', on numerical evaluations of values of frequency mutagens different origin on 1 million. newborn. On last evaluations, frequency of are all types of natural mutations on 1 million. newborn reaches 738 thousand. On this background an evaluation of values of mutations from irradiating by the dose in 1 Grey - from 3000 before 4700 more then modest. However real evaluation of danger of ionizing radiation to the account

  1. Abstracts of papers of international scientific conference 'Fundamental and applied aspects of radiobiology: Biological effects of low doses and radioactive contamination of environment (Radioecological and medical biological consequences of the Chernobyl NPP accident)'

    International Nuclear Information System (INIS)

    The results of research works executed in Belarus, as well as in Ukraine and Russia, on various aspects of the Chernobyl problematic are given: radiation medicine and risks, radiobiological effects and their forecasting, radioecology and agricultural radiology, decontamination and radioactive wastes management, socio economic and psychological problems caused by the Chernobyl NPP accident

  2. Radiobiology with DNA ligands

    International Nuclear Information System (INIS)

    The paper deals with the following topics: labelling of DNA ligands and other tumour-affinic compounds with 4.15-d 124I, radiotoxicity of Hoechst 33258 and 33342 and of iodinated Hoechst 33258 in cell cultures, preparation of 76Br-, 123I-, and 221At-labelled 5-halo-2'-deoxyuridine, chemical syntheses of boron derivatives of Hoechst 33258.III., Gadolinium neutron capture therapy

  3. Neutron radiobiology revisited

    International Nuclear Information System (INIS)

    The present paper reviews the experimental results of normal tissue and tumour studies in animals. The dose per fraction dependence of the RBE in normal tissues has been long recognised, together with the steeper increase of RBE at low doses for late responding tissues compared with acute reactions. The dose dependence for tumours is more complex, because of hypoxia and reoxygenation, as well as differences in repair capability after high LET damage. A comparison of tumour and normal tissue RBE values shows that there is little experimental evidence for a therapeutic advantage at clinically relevant doses. In particular, the RBE for slow growing tumours is even lower than that for the faster growing mouse tumours. The reasons for the loss of expected neutron benefits in clinically relevant experiments are discussed. The disappointing prospects for neutrons are contrasted with the current multifactorial approaches to overcoming resistance to more conventional low LET radiations, including acceleration, hyperfractionation and several types of hypoxic cell radiosensitizers. (orig.)

  4. Meson radiobiology and therapy

    International Nuclear Information System (INIS)

    High-linear energy transfer radiation (neutrons, heavy ions, and pions) have a greater relative biological effectiveness than low-linear energy transfer radiation by depositing a high density of ionization in irradiated cells. This overcomes the protective effect of oxygen; decreases the variation in sensitivity among the several stages of the cell cycles; and, inhibits the repair of sublethal damage as compared to x-rays, gamma rays, electrons and protons. Negative pi mesons (pions), appear particularly suited for radiation therapy as their penetration and depth-dose profiles lend themselves to shaping the high dose area to the tumor size and location. Preliminary biological experiments with pions produced at the Los Alamos Meson Physics Facility studied cell survival at various radiation depths and cell cycle sensitivity. Histologic study of data from the first human experiments indicated severe tumor cell destruction by pions as compared to x-rays in treating malignant melanoma skin nodules, without increased effects on dermal elements. (U.S.)

  5. Military radiobiology: A perspective

    International Nuclear Information System (INIS)

    Acute medical consequences affecting military personnel fall into two major classes: early events affecting performance and later more lethal events associated with single and combined injuries. If cells survive the radiation insult, they have the capability for repair. But the patient must survive fluid loss, infection, and bleeding defects until this can occur. Although no one can ever eliminate the incomprehensible destruction of human life associated with the use of nuclear weapons, significant medical advances can be achieved that will increase the performance and recovery of persons exposed to these weapons. Furthermore, these medical advances will go far toward improving the life and functioning of persons undergoing radiotherapy, trauma, accidental exposures, or a variety of other clinical situations. In the near future, the military battlefield will move into another dimension - space. Once outside the geomagnetic shield of the earth, military prsonnel will be exposed to a formidable array of new radiations. Among the new radiations will be high solar energy, solar particles and flares, and heavy nuclei from galactic cosmic arrays. Associated stresses will be microgravity, vibration, and isolation. To protect man in these new environments will truly challenge our ingenuity. This book looks at various medical consequences we face as a result of nuclear energy

  6. Monte Carlo dose calculations and radiobiological modelling: analysis of the effect of the statistical noise of the dose distribution on the probability of tumour control

    International Nuclear Information System (INIS)

    The aim of this work is to investigate the influence of the statistical fluctuations of Monte Carlo (MC) dose distributions on the dose volume histograms (DVHs) and radiobiological models, in particular the Poisson model for tumour control probability (tcp). The MC matrix is characterized by a mean dose in each scoring voxel, d, and a statistical error on the mean dose, σd; whilst the quantities d and σd depend on many statistical and physical parameters, here we consider only their dependence on the phantom voxel size and the number of histories from the radiation source. Dose distributions from high-energy photon beams have been analysed. It has been found that the DVH broadens when increasing the statistical noise of the dose distribution, and the tcp calculation systematically underestimates the real tumour control value, defined here as the value of tumour control when the statistical error of the dose distribution tends to zero. When increasing the number of energy deposition events, either by increasing the voxel dimensions or increasing the number of histories from the source, the DVH broadening decreases and tcp converges to the 'correct' value. It is shown that the underestimation of the tcp due to the noise in the dose distribution depends on the degree of heterogeneity of the radiobiological parameters over the population; in particular this error decreases with increasing the biological heterogeneity, whereas it becomes significant in the hypothesis of a radiosensitivity assay for single patients, or for subgroups of patients. It has been found, for example, that when the voxel dimension is changed from a cube with sides of 0.5 cm to a cube with sides of 0.25 cm (with a fixed number of histories of 108 from the source), the systematic error in the tcp calculation is about 75% in the homogeneous hypothesis, and it decreases to a minimum value of about 15% in a case of high radiobiological heterogeneity. The possibility of using the error on the tcp to

  7. Hypo-fractionated treatment in radiotherapy: radio-biological models Tcp and NTCP; Tratamiento hipofraccionado en radioterapia: modelos radiobiologicos TCP y NTCP

    Energy Technology Data Exchange (ETDEWEB)

    Astudillo V, A. J.; Mitsoura, E. [Universidad Autonoma del Estado de Mexico, Facultad de Medicina, Paseo Tollocan s/n, 50180 Toluca, Estado de Mexico (Mexico); Paredes G, L. [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico); Resendiz G, G., E-mail: lydia.paredes@inin.gob.mx [Hospital Medica Sur, Departamento de Radioterapia, Puente de Piedra 150, Col. Toriello Guerra, 14050 Mexico D. F. (Mexico)

    2014-08-15

    At the present time the breast cancer in Mexico has the first place of incidence of the malignant neoplasia s in the women, and represents 11.34% of all the cancer cases. On the other hand, the treatments for cancer by means of ionizing radiations have been dominated under the approaches of the medical radio-oncologists which have been based on test and error by many years. The radio-biological models, as the Tcp, NTCP and dosimetric variables, for their clinical application in the conventional radiotherapy with hypo-fractionation have as purpose predicting personalized treatment plans that they present most probability of tumor control and minor probability of late reactions, becoming this way support tools in the decisions taking for the patient treatments planning of Medical Physicists and Radio-oncologists. (Author)

  8. Three-dimensional radiobiological dosimetry (3D-RD) with {sup 124}I PET for {sup 131}I therapy of thyroid cancer

    Energy Technology Data Exchange (ETDEWEB)

    Sgouros, George; Hobbs, Robert F.; Wahl, Richard L. [Johns Hopkins University, School of Medicine, The Russell H. Morgan Department of Radiology, Division of Nuclear Medicine, Baltimore, MD (United States); Atkins, Francis B.; Nostrand, Douglas van [The Washington Hospital Center, Division of Nuclear Medicine, Washington, DC (United States); Ladenson, Paul W. [Johns Hopkins University, School of Medicine, Department of Endocrinology, Baltimore, MD (United States)

    2011-06-15

    Radioiodine therapy of thyroid cancer was the first and remains among the most successful radiopharmaceutical (RPT) treatments of cancer although its clinical use is based on imprecise dosimetry. The positron emitting radioiodine, {sup 124}I, in combination with positron emission tomography (PET)/CT has made it possible to measure the spatial distribution of radioiodine in tumors and normal organs at high resolution and sensitivity. The CT component of PET/CT has made it simpler to match the activity distribution to the corresponding anatomy. These developments have facilitated patient-specific dosimetry (PSD), utilizing software packages such as three-dimensional radiobiological dosimetry (3D-RD), which can account for individual patient differences in pharmacokinetics and anatomy. We highlight specific examples of such calculations and discuss the potential impact of {sup 124}I PET/CT on thyroid cancer therapy. (orig.)

  9. Simulations of a vacuum window and in-beam ion detection for use in radiobiological experiments with 50 MeV particle beams

    International Nuclear Information System (INIS)

    The vacuum window and in-beam ion detection of a radiobiological endstation have been studied using the Monte Carlo particle transport code MCNPX 2.5.0, investigating the effects of different elements on an incident beam of 50 MeV protons. The scattering and energy spread as well as secondary particle generation are analysed. A 200 nm thick silicon nitride vacuum window was found to have the least effect on the incident beam, giving an energy spread of 5.01(8)× 10−4 MeV. Placing a silicon pixel detector before the sample caused scattering of the beam of around 15 μm in radius; too much to be used for experiments targeting individual nuclei

  10. Further analysis of radiobiological parameters from the first and second British Institute of Radiology randomized studies of larynx/pharynx radiotherapy

    International Nuclear Information System (INIS)

    Purpose: This retrospective analysis of 1345 patients treated for cancer of the larynx or pharynx by randomization into two groups in each center in two separate trials of fractionated radiotherapy was carried out in an attempt to extract the radiobiological parameters α (dose), β (fraction size), and γ (overall time) from the data. Methods and Materials: Details of the trials have been published previously. In the first, 734 patients were randomized to either five or three fractions per week, in centers each using their own overall time, which varied from 3 to 7 weeks in different centers. In the second trial, 611 patients were randomized to 'short' (≤ 4 weeks) or 'long' (4-7 weeks) overall time. We combine the data from both studies and use the linear-quadratic formula with logistic regression and maximum-likelihood methods to obtain the radiobiological factors, taking into account other variables such as stage or age, when significant. Results: The parameters calculated for local tumor control showed significant estimates of α, very small estimates of β, and significant values of γ. The derived estimates of α/β were large, but very variable. The time-dose tradeoff-γ/α was 0.76 Gy/day for larynx and 0.3 Gy/day for pharynx tumors (not significantly different from each other). Late complications gave indeterminate α/β ratios and a time-dose factor not significantly different from zero. Acute normal-tissue effects gave α/β estimates of 8-9 Gy and time factors of 0.8-0.9 Gy/day. Conclusions: The results are consistent with other published values with the exception that significant time factors for late complications could not be excluded

  11. Dosimetry and radiobiology at the new RA-3 reactor boron neutron capture therapy (BNCT) facility: application to the treatment of experimental oral cancer.

    Science.gov (United States)

    Pozzi, E; Nigg, D W; Miller, M; Thorp, S I; Heber, E M; Zarza, L; Estryk, G; Monti Hughes, A; Molinari, A J; Garabalino, M; Itoiz, M E; Aromando, R F; Quintana, J; Trivillin, V A; Schwint, A E

    2009-07-01

    The National Atomic Energy Commission of Argentina (CNEA) constructed a novel thermal neutron source for use in boron neutron capture therapy (BNCT) applications at the RA-3 research reactor facility located in Buenos Aires. The aim of the present study was to perform a dosimetric characterization of the facility and undertake radiobiological studies of BNCT in an experimental model of oral cancer in the hamster cheek pouch. The free-field thermal flux was 7.1 x 10(9) n cm(-2)s(-1) and the fast neutron flux was 2.5 x 10(6) n cm(-2)s(-1), indicating a very well-thermalized neutron field with negligible fast neutron dose. For radiobiological studies it was necessary to shield the body of the hamster from the neutron flux while exposing the everted cheek pouch bearing the tumors. To that end we developed a lithium (enriched to 95% in (6)Li) carbonate enclosure. Groups of tumor-bearing hamsters were submitted to BPA-BNCT, GB-10-BNCT, (GB-10+BPA)-BNCT or beam only treatments. Normal (non-cancerized) hamsters were treated similarly to evaluate normal tissue radiotoxicity. The total physical dose delivered to tumor with the BNCT treatments ranged from 6 to 8.5 Gy. Tumor control at 30 days ranged from 73% to 85%, with no normal tissue radiotoxicity. Significant but reversible mucositis in precancerous tissue surrounding tumors was associated to BPA-BNCT. The therapeutic success of different BNCT protocols in treating experimental oral cancer at this novel facility was unequivocally demonstrated. PMID:19380233

  12. Dosimetry and radiobiology at the new RA-3 reactor boron neutron capture therapy (BNCT) facility: Application to the treatment of experimental oral cancer

    International Nuclear Information System (INIS)

    The National Atomic Energy Commission of Argentina (CNEA) constructed a novel thermal neutron source for use in boron neutron capture therapy (BNCT) applications at the RA-3 research reactor facility located in Buenos Aires. The aim of the present study was to perform a dosimetric characterization of the facility and undertake radiobiological studies of BNCT in an experimental model of oral cancer in the hamster cheek pouch. The free-field thermal flux was 7.1x109 n cm-2 s-1 and the fast neutron flux was 2.5x106 n cm-2 s-1, indicating a very well-thermalized neutron field with negligible fast neutron dose. For radiobiological studies it was necessary to shield the body of the hamster from the neutron flux while exposing the everted cheek pouch bearing the tumors. To that end we developed a lithium (enriched to 95% in 6Li) carbonate enclosure. Groups of tumor-bearing hamsters were submitted to BPA-BNCT, GB-10-BNCT, (GB-10+BPA)-BNCT or beam only treatments. Normal (non-cancerized) hamsters were treated similarly to evaluate normal tissue radiotoxicity. The total physical dose delivered to tumor with the BNCT treatments ranged from 6 to 8.5 Gy. Tumor control at 30 days ranged from 73% to 85%, with no normal tissue radiotoxicity. Significant but reversible mucositis in precancerous tissue surrounding tumors was associated to BPA-BNCT. The therapeutic success of different BNCT protocols in treating experimental oral cancer at this novel facility was unequivocally demonstrated.

  13. Dosimetry and radiobiology at the new RA-3 reactor boron neutron capture therapy (BNCT) facility: Application to the treatment of experimental oral cancer

    Energy Technology Data Exchange (ETDEWEB)

    Pozzi, E. [Research and Production Reactors, National Atomic Energy Commission, Ezeiza Atomic Center (Argentina); Department of Radiobiology, National Atomic Energy Commission, Constituyentes Atomic Center (Argentina)], E-mail: epozzi@cnea.gov.ar; Nigg, D.W. [Idaho National Laboratory, Idaho Falls (United States); Miller, M.; Thorp, S.I. [Instrumentation and Control Department, National Atomic Energy Commission, Ezeiza Atomic Center (Argentina); Heber, E.M. [Department of Radiobiology, National Atomic Energy Commission, Constituyentes Atomic Center (Argentina); Zarza, L.; Estryk, G. [Research and Production Reactors, National Atomic Energy Commission, Ezeiza Atomic Center (Argentina); Monti Hughes, A.; Molinari, A.J.; Garabalino, M. [Department of Radiobiology, National Atomic Energy Commission, Constituyentes Atomic Center (Argentina); Itoiz, M.E. [Department of Radiobiology, National Atomic Energy Commission, Constituyentes Atomic Center (Argentina); Department of Oral Pathology, Faculty of Dentistry, University of Buenos Aires (Argentina); Aromando, R.F. [Department of Oral Pathology, Faculty of Dentistry, University of Buenos Aires (Argentina); Quintana, J. [Research and Production Reactors, National Atomic Energy Commission, Ezeiza Atomic Center (Argentina); Trivillin, V.A.; Schwint, A.E. [Department of Radiobiology, National Atomic Energy Commission, Constituyentes Atomic Center (Argentina)

    2009-07-15

    The National Atomic Energy Commission of Argentina (CNEA) constructed a novel thermal neutron source for use in boron neutron capture therapy (BNCT) applications at the RA-3 research reactor facility located in Buenos Aires. The aim of the present study was to perform a dosimetric characterization of the facility and undertake radiobiological studies of BNCT in an experimental model of oral cancer in the hamster cheek pouch. The free-field thermal flux was 7.1x10{sup 9} n cm{sup -2} s{sup -1} and the fast neutron flux was 2.5x10{sup 6} n cm{sup -2} s{sup -1}, indicating a very well-thermalized neutron field with negligible fast neutron dose. For radiobiological studies it was necessary to shield the body of the hamster from the neutron flux while exposing the everted cheek pouch bearing the tumors. To that end we developed a lithium (enriched to 95% in {sup 6}Li) carbonate enclosure. Groups of tumor-bearing hamsters were submitted to BPA-BNCT, GB-10-BNCT, (GB-10+BPA)-BNCT or beam only treatments. Normal (non-cancerized) hamsters were treated similarly to evaluate normal tissue radiotoxicity. The total physical dose delivered to tumor with the BNCT treatments ranged from 6 to 8.5 Gy. Tumor control at 30 days ranged from 73% to 85%, with no normal tissue radiotoxicity. Significant but reversible mucositis in precancerous tissue surrounding tumors was associated to BPA-BNCT. The therapeutic success of different BNCT protocols in treating experimental oral cancer at this novel facility was unequivocally demonstrated.

  14. Dosimetric and radiobiological comparison of CyberKnife M6™ InCise multileaf collimator over IRIS™ variable collimator in prostate stereotactic body radiation therapy.

    Science.gov (United States)

    Kathriarachchi, Vindu; Shang, Charles; Evans, Grant; Leventouri, Theodora; Kalantzis, Georgios

    2016-01-01

    The impetus behind our study was to establish a quantitative comparison between the IRIS collimator and the InCise multileaf collimator (MLC) (Accuray Inc. Synnyvale, CA) for prostate stereotactic body radiation therapy (SBRT). Treatment plans for ten prostate cancer patients were performed on MultiPlan™ 5.1.2 treatment planning system utilizing MLC and IRIS for 36.25 Gy in five fractions. To reduce the magnitude of variations between cases, the planning tumor volume (PTV) was defined and outlined for treating prostate gland only, assuming no seminal vesicle or ex-capsule involvement. Evaluation indices of each plan include PTV coverage, conformity index (CI), Paddick's new CI, homogeneity index, and gradient index. Organ at risk (OAR) dose sparing was analyzed by the bladder wall Dmax and V37Gy, rectum Dmax and V36Gy. The radiobiological response was evaluated by tumor control probability and normal tissue complication probability based on equivalent uniform dose. The dose delivery efficiency was evaluated on the basis of planned monitor units (MUs) and the reported treatment time per fraction. Statistical significance was tested using the Wilcoxon signed rank test. The studies indicated that CyberKnife M6™ IRIS and InCise™ MLC produce equivalent SBRT prostate treatment plans in terms of dosimetry, radiobiology, and OAR sparing, except that the MLC plans offer improvement of the dose fall-off gradient by 29% over IRIS. The main advantage of replacing the IRIS collimator with MLC is the improved efficiency, determined from the reduction of MUs by 42%, and a 36% faster delivery time. PMID:27217626

  15. Dosimetric and radiobiological comparison of CyberKnife M6™ InCise multileaf collimator over IRIS™ variable collimator in prostate stereotactic body radiation therapy

    Science.gov (United States)

    Kathriarachchi, Vindu; Shang, Charles; Evans, Grant; Leventouri, Theodora; Kalantzis, Georgios

    2016-01-01

    The impetus behind our study was to establish a quantitative comparison between the IRIS collimator and the InCise multileaf collimator (MLC) (Accuray Inc. Synnyvale, CA) for prostate stereotactic body radiation therapy (SBRT). Treatment plans for ten prostate cancer patients were performed on MultiPlan™ 5.1.2 treatment planning system utilizing MLC and IRIS for 36.25 Gy in five fractions. To reduce the magnitude of variations between cases, the planning tumor volume (PTV) was defined and outlined for treating prostate gland only, assuming no seminal vesicle or ex-capsule involvement. Evaluation indices of each plan include PTV coverage, conformity index (CI), Paddick's new CI, homogeneity index, and gradient index. Organ at risk (OAR) dose sparing was analyzed by the bladder wall Dmax and V37Gy, rectum Dmax and V36Gy. The radiobiological response was evaluated by tumor control probability and normal tissue complication probability based on equivalent uniform dose. The dose delivery efficiency was evaluated on the basis of planned monitor units (MUs) and the reported treatment time per fraction. Statistical significance was tested using the Wilcoxon signed rank test. The studies indicated that CyberKnife M6™ IRIS and InCise™ MLC produce equivalent SBRT prostate treatment plans in terms of dosimetry, radiobiology, and OAR sparing, except that the MLC plans offer improvement of the dose fall-off gradient by 29% over IRIS. The main advantage of replacing the IRIS collimator with MLC is the improved efficiency, determined from the reduction of MUs by 42%, and a 36% faster delivery time. PMID:27217626

  16. Conservative surgery and adjuvant radiation therapy in the management of adult soft tissue sarcoma of the extremities: clinical and radiobiological results

    International Nuclear Information System (INIS)

    Purpose: The outcome of adult patients with soft tissue sarcoma of the extremities treated with conservative surgery and adjuvant irradiation was evaluated to (a) determine the appropriate treatment volume and radiation dosage in the postoperative setting, and (b) correlate in vitro radiobiological parameters obtained prior to therapy with clinical outcome. Methods and Materials: Sixty-four consecutive adult patients with soft tissue sarcoma of the extremities (40 lower, 24 upper) who underwent conservative surgery and adjuvant irradiation (7 preoperative, 50 postoperative, 7 perioperative) between 1978 and 1991 were reviewed. The initial radiation field margin surrounding the tumor bed/scar was retrospectively analyzed in all postoperative patients. Initial field margins were < 5 cm in 12 patients, 5-9.9 cm in 32 and ≥ 10 cm in 6. Patients with negative pathological margins were initially treated with traditional postoperative doses (64-66 Gy); however, in later years the postoperative dose was reduced to 60 Gy. Thirteen cell lines were established prior to definite therapy, and radiobiological parameters (multitarget and linear-quadratic) were obtained and correlated with outcome. Results: Postoperative patients treated with an initial field margin of < 5 cm had a 5-year local control of 30.4% vs. 93.2% in patients treated with an initial margin of ≥ 5 cm (p = 0.0003). Five-year local control rates were similar in patients treated with initial field margins of 5-9.9 cm (91.6%) compared with those treated with ≥ 10 cm margins (100%) (p = 0.49). While postoperative patients receiving < 60 Gy had a worse local control than those receiving ≥ 60 Gy (p = 0.08), no difference was seen in local control between patients receiving less than traditional postoperative doses (60-63.9 Gy) (74.4%) vs. those receiving 64-66 Gy (87.0%) (p = 0.5). The local control of patients treated in the later years of the study, with strict attention to surgical and radiotherapeutic

  17. Radioembolization of hepatocarcinoma with {sup 90}Y glass microspheres: development of an individualized treatment planning strategy based on dosimetry and radiobiology

    Energy Technology Data Exchange (ETDEWEB)

    Chiesa, C.; Maccauro, M.; Aliberti, G.; Padovano, B.; Seregni, E.; Crippa, F. [Foundation IRCCS Istituto Nazionale Tumori, Nuclear Medicine Division, Milan (Italy); Mira, M.; Negri, A. [University of Milan, Postgraduate Health Physics School, Milan (Italy); Spreafico, C.; Morosi, C.; Civelli, E.; Lanocita, R.; Marchiano, A. [Foundation IRCCS Istituto Nazionale Tumori, Radiology 2, Milan (Italy); Romito, R.; Sposito, C.; Bhoori, S.; Facciorusso, A.; Mazzaferro, V. [Foundation IRCCS Istituto Nazionale Tumori, Surgery 1, Milan (Italy); Camerini, T. [Foundation IRCCS Istituto Nazionale Tumori, Scientific Direction, Milan (Italy); Carrara, M. [Foundation IRCCS Istituto Nazionale Tumori, Health Physics, Milan (Italy); Pellizzari, S. [University La Sapienza, Engineering Faculty, Rome (Italy); Migliorisi, M. [Foundation IRCCS Istituto Nazionale Tumori, Nuclear Medicine Division, Milan (Italy); Foundation IRCCS Istituto Nazionale Tumori, Clinical Engineering, Milan (Italy); De Nile, M.C. [University of Pavia, Physics Faculty, Pavia, Lombardy (Italy)

    2015-10-15

    The aim of this study was to optimize the dosimetric approach and to review the absorbed doses delivered, taking into account radiobiology, in order to identify the optimal methodology for an individualized treatment planning strategy based on {sup 99m}Tc-macroaggregated albumin (MAA) single photon emission computed tomography (SPECT) images. We performed retrospective dosimetry of the standard TheraSphere registered treatment on 52 intermediate (n = 17) and advanced (i.e. portal vein thrombosis, n = 35) hepatocarcinoma patients with tumour burden < 50 % and without obstruction of the main portal vein trunk. Response was monitored with the densitometric radiological criterion (European Association for the Study of the Liver) and treatment-related liver decompensation was defined ad hoc with a time cut-off of 6 months. Adverse events clearly attributable to disease progression or other causes were not attributed to treatment. Voxel dosimetry was performed with the local deposition method on {sup 99m}Tc-MAA SPECT images. The reconstruction protocol was optimized. Concordance of {sup 99m}Tc-MAA and {sup 90}Y bremsstrahlung microsphere biodistributions was studied in 35 sequential patients. Two segmentation methods were used, based on SPECT alone (home-made code) or on coregistered SPECT/CT images (IMALYTICS trademark by Philips). STRATOS trademark absorbed dose calculation was validated for {sup 90}Y with a single time point. Radiobiology was used introducing other dosimetric variables besides the mean absorbed dose D: equivalent uniform dose (EUD), biologically effective dose averaged over voxel values (BED{sub ave}) and equivalent uniform biologically effective dose (EUBED). Two sets of radiobiological parameters, the first derived from microsphere irradiation and the second from external beam radiotherapy (EBRT), were used. A total of 16 possible methodologies were compared. Tumour control probability (TCP) and normal tissue complication probability (NTCP) were

  18. Development of a single ion micro-irradiation facility for experimental radiobiology at cell level; Developpement d'une ligne d'irradiation microfaisceau en mode ion par ion pour la radiobiologie experimentale a l'echelle cellulaire

    Energy Technology Data Exchange (ETDEWEB)

    Barberet, Ph

    2003-10-01

    A micro-irradiation device has been developed for radiobiology applications at the scale of the cell. This device is based on an upgrade of an existing micro-beam line that was already able to deliver a 1 to 3 MeV proton or alpha beam of low intensity and whose space resolution is lower than 1 micrometer in vacuum. The important part of this work has been the development of an irradiation stage designed to fit on the micro-probe and able to deliver ions in the air with an absolute accuracy of a few micrometers. A program has been set up to monitor the complete irradiation line in testing and in automatic irradiation operating phases. Simulation tools based on Monte-Carlo calculations have been validated through comparisons with experimental data particularly in the field of spatial resolution and of the number of ions delivered. The promising results show the possibility in a near future to use this tool to study the response of cells to very low irradiation doses down to the extreme limit of one ion per cell.

  19. Preparation of intravenous cytostatic mixtures: one-year work experience at the Pharmaceutical Service of the Nacional Institute of Oncology and Radiobiology

    International Nuclear Information System (INIS)

    From October 2006 to September 2007, which marked the beginning of the preparation of intravenous cytostatic mixtures by the Pharmaceutical Service of the National Institute of Oncology and Radiobiology, a number of results were achieved and then considered for analysis in this paper. The selected indicators included the number of detected and/or avoided medication errors, cytostatics consumption, therapies recovered through centralized preparation and the implementation of Good Practices of Preparation and Pharmacy. The results were compared with those of similar periods of time in previous years. It was observed that the involvement of the pharmacist in the oncological chemotherapy team contributed to recovering costly therapies such as 80 mg Docetaxel, 300 mg Paclitaxel and 150 mg Transtuzomab ampules. One hundred and twenty one patients could potentially benefit from these therapies, mainly those suffering breast cancer. The consumption of cytostatic drugs such as 1 mg Vincristine and 15 mg Bleomycin ampules decreased; the application of technical and economic control evidenced an increased use of 200 mg Cyclophosphamide and 10 mg Cisplatine ampules. Besides, 1,3% medication errors in prescription was detected and avoided, although this is still a high figure. It was concluded that the involvement of a pharmacist in the medical team improves the quality of service in those hospitals that care for oncological patients. It was suggested that a pharmacist should be incorporated into the medical teams of other hospital centers throughout the country since this encourages the implementation of Good Practices of Preparation and contributes to minimizing medication errors. (Author)

  20. 30th and 29th anniversary of reactor accidents in A-1 nuclear power plant Jaslovske Bohunice - radioecological and radiobiological consequences

    International Nuclear Information System (INIS)

    In this paper authors present facts about construction, operation and reactor accidents in A-1 Nuclear Power Plant Jaslovske Bohunice, Slovakia. There was the reactor KS 150 (HWGCR) cooled with carbon dioxide and moderated with heavy water. A-1 NPP was commissioned on December 25, 1972. The first reactor accident happened on January 5, 1976 during fuel loading. Two persons of personal died by suffocation with carbon dioxide. This accident has been not evaluated according to the INES scale up to present time. The second serious accident in A-1 NPP occurred in February 22, 1977 also during fuel loading. This INES level 4 of reactor accident resulted in damaged fuel integrity with extensive corrosion damage of fuel cladding and release of radioactivity into the plant area. The A-1 NPP was consecutively shut down and is being decommissioned in the present time. Both reactor accidents are described in this paper. Some radioecological and radiobiological consequences of accidents and contamination of area of A-1 NPP as well as of Manivier canal and Dudvah River as result of flooding during the decommissioning are presented. (authors)

  1. The world's high background natural radiation areas (HBNRAs) revisited: A broad overview of the dosimetric, epidemiological and radiobiological issues

    International Nuclear Information System (INIS)

    The residents of the world's high background natural radiation areas (HBNRAs), such as Ramsar (in Iran), Guarapari (in Brazil), Orissa and Kerala (in India) and Yangjiang (in China) have lived in these areas for generations under extraordinary radiation fields. The failure of earlier epidemiological studies to report any substantial increase in cancer incidence in HBNRAs has raised some controversy regarding the validity of the linear no-threshold hypothesis. This paper reviews some of the most recent studies of HBNRAs with the intent of stimulating greater research interest in the dosimetric, epidemiological and radiobiological issues related to the world's HBNRAs and proposes solutions to the challenges facing HBNRA studies. This paper may serve as a useful reference for some of the harder-to-find literature. - Highlights: • Some of the challenging issues of HBNRAs have not been resolved. • A literature review of the most recent studies of HBNRAs has been conducted. • An overview of some of the challenging issues and viable solutions are presented

  2. Comparison of cytogenetic effects in bone marrow of mice after the flight on the biosatellite "BION-M1" and the ground-based radiobiological experiment

    Science.gov (United States)

    Dorozhkina, Olga; Vorozhtsova, Svetlana; Ivanov, Alexander

    2016-07-01

    During space flight, the astronauts are exposed to radiation exposure at low doses with low dose rates, so one of the actual areas of Radiobiology is research of action of ionizing radiation in low and ultra-low doses. Violation of the chromosome apparatus of living biosystems, ranging from viruses and bacteria to humans, is the most reliable evidence of exposure to ionizing radiation. In this regard, the study of cytogenetic damage in the cells of humans and animals is central to space radiobiology (Fedorenko B.S., 2006). In experiment "BION - M1" by anaphase method was determined level of chromosomal aberrations in bone marrow cells of tibia of mice. Flight duration biosatellite "BION - M1" (Sychev V.N. et al., 2014) was 30 days in Earth orbit. Euthanasia of experimental animals was carried out after 12 hours from the moment of landing satellite by method of cervical dislocation. The level of chromosomal aberrations in vivarium-housed control mice was 1,75 ± 0,6% and 1,8 ± 0,45%, while the mitotic index 1,46 ± 0,09% and 1,53 ± 0,05%. The content of animals in the experiment with onboard equipment led to some increase in aberrant mitosis (2,3 ± 0,4%) and reduction of the mitotic index (1,37 ± 0,02%). In the flight experiment "BION-M1" was a statistically significant increase in level of chromosome aberrations (29,7 ± 4,18%) and a decrease in the mitotic index (0,74 ± 0,07%). According to VA Shurshakova (2014), the radiation dose to mice ranged from 32 to 72 mGy and relate to a range of small doses (ICRP, 2012). In this connection we conducted a series of experiments in the ground conditions, the aim of which was the study of earliest effects of ionizing radiation in vivo in mice irradiated with low doses of γ-irradiation of 10 to 200 mGy in the first 24 hours after exposure, i.e. within the first post-radiation exposure cell cycle. Studies were carried out on adult female mice outbred ICR (CD-1) - SPF category at the age of 4-4.5 months with an average

  3. Accidental tritium release from nuclear technologies and a radiobiological survey of the impact of low dose tritium on the developing mouse brain

    International Nuclear Information System (INIS)

    Full text: The Atomic Energy Act, 1962 provides for the development of the peaceful uses of atomic energy for the welfare of the people in India. The licensing policy adopted for nuclear power stations in India requires that the plants meet stringent requirements based on the system of dose limitation, recommended by the International Commission of Radiological Protection (ICRP). Currently, nuclear energy is contributing just 3% of the country's power generation. The share of nuclear power is proposed to be increased to 10% in the near future. With the introduction of nuclear energy, the need to assess the radioecological and radiobiological impact of radionuclides of long half- life existing in the environment for longer duration has appeared. Tritium, a radioactive by-product of power reactors is one of such major radionuclides of concern. In the world, routine releases and accidental spills of tritium from nuclear power plants pose a growing health and safety concern. Tritium has been observed in ground water in the vicinity of several nuclear stations. Exposure to tritium has been clinically proven to cause deleterious and detectable effects such as teratogenesis, cancer and life shortening in laboratory animals. There is, now, a growing emphasis on tritium in radiation protection as the challenge of nuclear fusion comes nearer. Present investigation is an attempt to elucidate the effects of low dose tritiated water exposure on developing mouse cerebellum. Pregnant Swiss albino mice (12-15 in number were given a priming injection 7.4 and 74 kBq/ml of body water) of tritiated water (HTO) on 16th day of gestation. From the same day onward, through parturition, till the last interval studied, the pregnant females were continuously maintained respectively on 11.1 and 111 kBq/ml of tritiated drinking water provided ad libidum. After cervical dislocation the litters were autopsied on 1, 3, 5 and 6 weeks post- partum. Brains were fixed and then cerebellum from each of

  4. The in vivo study on the radiobiologic effect of prolonged delivery time to tumor control in C57BL mice implanted with Lewis lung cancer

    Directory of Open Access Journals (Sweden)

    Zhu Guo-Pei

    2011-01-01

    Full Text Available Abstract Background High-precision radiation therapy techniques such as IMRT or sterotactic radiosurgery, delivers more complex treatment fields than conventional techniques. The increased complexity causes longer dose delivery times for each fraction. The purpose of this work is to explore the radiobiologic effect of prolonged fraction delivery time on tumor response and survival in vivo. Methods 1-cm-diameter Lewis lung cancer tumors growing in the legs of C57BL mice were used. To evaluate effect of dose delivery prolongation, 18 Gy was divided into different subfractions. 48 mice were randomized into 6 groups: the normal control group, the single fraction with 18 Gy group, the two subfractions with 30 min interval group, the seven subfractions with 5 min interval group, the two subfractions with 60 min interval group and the seven subfractions with 10 min interval group. The tumor growth tendency, the tumor growth delay and the mice survival time were analyzed. Results The tumor growth delay of groups with prolonged delivery time was shorter than the group with single fraction of 18 Gy (P 0.05. Compared to the group with single fraction of 18 Gy, the groups with prolonged delivery time shorten the mice survival time while there was no significant difference between the groups with prolonged delivery time 30 min and the groups with prolonged delivery time 60 min. Conclusions The prolonged delivery time with same radiation dose shorten the tumor growth delay and survival time in the mice implanted with Lewis lung cancer. The anti-tumor effect decreased with elongation of the total interfractional time.

  5. Revising the Radiobiological Model of Synchronous Chemotherapy in Head-and-Neck Cancer: A New Analysis Examining Reduced Weighting of Accelerated Repopulation

    International Nuclear Information System (INIS)

    Purpose: Previous studies of synchronous chemoradiation therapy have modeled the additional effect of chemotherapy as additional radiation therapy biologically effective dose (BED). Recent trials of accelerated versus conventional fractionation chemoradiation have cast doubt on such modeling. The purpose of this study was to identify alternative models. Methods and Materials: Nine trials of platinum-based chemoradiation were identified. In radiation therapy-alone arms, the radiation therapy BED for tumor was calculated using standard parameters. In chemoradiation arms, 3 methods were used to calculate tumor BED (tBED): additional BED, addition of 9.3 Gy BED for tumor to the radiation therapy BED; zero repopulation, BED with no correction for repopulation; variable tp (the average doubling time during accelerated repopulation), values of tp 3-10 were used to examine a partial suppression of repopulation. The correlations between the calculated percentage change in tBED for each method and observed percentage change in local control were assessed using the Pearson product moment correlation. Results: Significant correlations were obtained for all 3 methods but were stronger with zero repopulation (P=.0002) and variable tp (tp = 10) (P=.0005) than additional BED (P=.02). Conclusions: Radiobiological models using modified parameters for accelerated repopulation seem to correlate strongly with outcome in chemoradiation studies. The variable tp method shows strong correlation for outcome in local control and is potentially a more suitable model in the chemoradiation setting. However, a lack of trials with an overall treatment time of more than 46 days inhibits further differentiation of the optimal model

  6. Radiobiologic Parameters and Local Effect Model Predictions for Head-and-Neck Squamous Cell Carcinomas Exposed to High Linear Energy Transfer Ions

    International Nuclear Information System (INIS)

    Purpose: To establish the radiobiologic parameters of head-and-neck squamous cell carcinomas (HNSCC) in response to ion irradiation with various linear energy transfer (LET) values and to evaluate the relevance of the local effect model (LEM) in HNSCC. Methods and Materials: Cell survival curves were established in radiosensitive SCC61 and radioresistant SQ20B cell lines irradiated with [33.6 and 184 keV/n] carbon, [302 keV/n] argon, and X-rays. The results of ion experiments were confronted to LEM predictions. Results: The relative biologic efficiency ranged from 1.5 to 4.2 for SCC61 and 2.1 to 2.8 for SQ20B cells. Fixing an arbitrary D0 parameter, which characterized survival to X-ray at high doses (>10 Gy), gave unsatisfying LEM predictions for both cell lines. For D0 = 10 Gy, the error on survival fraction at 2 Gy amounted to a factor of 10 for [184 keV/n] carbon in SCC61 cells. We showed that the slope (smax) of the survival curve at high doses was much more reliable than D0. Fitting smax to 2.5 Gy-1 gave better predictions for both cell lines. Nevertheless, LEM could not predict the responses to fast and slow ions with the same accuracy. Conclusions: The LEM could predict the main trends of these experimental data with correct orders of magnitude while smax was optimized. Thus the efficiency of carbon ions cannot be simply extracted from the clinical response of a patient to X-rays. LEM should help to optimize planning for hadrontherapy if a set of experimental data is available for high-LET radiations in various types of tumors

  7. Radiobiological restrictions and tolerance doses of repeated single-fraction hdr-irradiation of intersecting small liver volumes for recurrent hepatic metastases

    Directory of Open Access Journals (Sweden)

    Wust Peter

    2010-05-01

    Full Text Available Abstract Background To assess radiobiological restrictions and tolerance doses as well as other toxic effects derived from repeated applications of single-fraction high dose rate irradiation of small liver volumes in clinical practice. Methods Twenty patients with liver metastases were treated repeatedly (2 - 4 times at identical or intersecting locations by CT-guided interstitial brachytherapy with varying time intervals. Magnetic resonance imaging using the hepatocyte selective contrast media Gd-BOPTA was performed before and after treatment to determine the volume of hepatocyte function loss (called pseudolesion, and the last acquired MRI data set was merged with the dose distributions of all administered brachytherapies. We calculated the BED (biologically equivalent dose for a single dose d = 2 Gy for different α/β values (2, 3, 10, 20, 100 based on the linear-quadratic model and estimated the tolerance dose for liver parenchyma D90 as the BED exposing 90% of the pseudolesion in MRI. Results The tolerance doses D90 after repeated brachytherapy sessions were found between 22 - 24 Gy and proved only slightly dependent on α/β in the clinically relevant range of α/β = 2 - 10 Gy. Variance analysis showed a significant dependency of D90 with respect to the intervals between the first irradiation and the MRI control (p 90 and the pseudolesion's volume. No symptoms of liver dysfunction or other toxic effects such as abscess formation occurred during the follow-up time, neither acute nor on the long-term. Conclusions Inactivation of liver parenchyma occurs at a BED of approx. 22 - 24 Gy corresponding to a single dose of ~10 Gy (α/β ~ 5 Gy. This tolerance dose is consistent with the large potential to treat oligotopic and/or recurrent liver metastases by CT-guided HDR brachytherapy without radiation-induced liver disease (RILD. Repeated small volume irradiation may be applied safely within the limits of this study.

  8. SU-E-T-375: Passive Scattering to Pencil-Beam-Scanning Comparison for Medulloblastoma Proton Therapy: LET Distributions and Radiobiological Implications

    Energy Technology Data Exchange (ETDEWEB)

    Giantsoudi, D; MacDonald, S; Paganetti, H [Massachusetts General Hospital and Harvard Medical School, Boston, MA (United States)

    2014-06-01

    Purpose: To compare the linear energy transfer (LET) distributions between passive scattering and pencil beam scanning proton radiation therapy techniques for medulloblastoma patients and study the potential radiobiological implications. Methods: A group of medulloblastoma patients, previously treated with passive scattering (PS) proton craniospinal irradiation followed by prosterior fossa or involved field boost, were selected from the patient database of our institution. Using the beam geometry and planning computed tomography (CT) image sets of the original treatment plans, pencil beam scanning (PBS) treatment plans were generated for the cranial treatment for each patient, with average beam spot size of 8mm (sigma in air at isocenter). 3-dimensional dose and LET distributions were calculated by Monte Carlo methods (TOPAS) both for the original passive scattering and new pencil beam scanning treatment plans. LET volume histograms were calculated for the target and OARs and compared for the two delivery methods. Variable RBE weighted dose distributions and volume histograms were also calculated using a variable dose and LET-based model. Results: Better dose conformity was achieved with PBS planning compared to PS, leading to increased dose coverage for the boost target area and decreased average dose to the structures adjacent to it and critical structures outside the whole brain treatment field. LET values for the target were lower for PBS plans. Elevated LET values for OARs close to the boosted target areas were noticed, due to end of range of proton beams falling inside these structures, resulting in higher RBE weighted dose for these structures compared to the clinical RBE value of 1.1. Conclusion: Transitioning from passive scattering to pencil beam scanning proton radiation treatment can be dosimetrically beneficial for medulloblastoma patients. LET–guided treatment planning could contribute to better decision making for these cases, especially for

  9. The in vivo study on the radiobiologic effect of prolonged delivery time to tumor control in C57BL mice implanted with Lewis lung cancer

    International Nuclear Information System (INIS)

    High-precision radiation therapy techniques such as IMRT or sterotactic radiosurgery, delivers more complex treatment fields than conventional techniques. The increased complexity causes longer dose delivery times for each fraction. The purpose of this work is to explore the radiobiologic effect of prolonged fraction delivery time on tumor response and survival in vivo. 1-cm-diameter Lewis lung cancer tumors growing in the legs of C57BL mice were used. To evaluate effect of dose delivery prolongation, 18 Gy was divided into different subfractions. 48 mice were randomized into 6 groups: the normal control group, the single fraction with 18 Gy group, the two subfractions with 30 min interval group, the seven subfractions with 5 min interval group, the two subfractions with 60 min interval group and the seven subfractions with 10 min interval group. The tumor growth tendency, the tumor growth delay and the mice survival time were analyzed. The tumor growth delay of groups with prolonged delivery time was shorter than the group with single fraction of 18 Gy (P < 0.05). The tumor grow delay of groups with prolonged delivery time 30 min was longer than that of groups with prolonged delivery time 60 min P < 0.05). There was no significant difference between groups with same delivery time (P > 0.05). Compared to the group with single fraction of 18 Gy, the groups with prolonged delivery time shorten the mice survival time while there was no significant difference between the groups with prolonged delivery time 30 min and the groups with prolonged delivery time 60 min. The prolonged delivery time with same radiation dose shorten the tumor growth delay and survival time in the mice implanted with Lewis lung cancer. The anti-tumor effect decreased with elongation of the total interfractional time

  10. Glaucous-winged gull nesting on Amchitka Island

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The glaucous-winged gull (Larus glaucescens) is the most common gull in the north Pacific (Bent 1921, Murie 1959). It is also one of the most abundant permanent...

  11. Modern Radiobiology: Contention Of Concepts: Advanced Technology And Development Of Effective Prophylaxis, Prevention And Treatment Of Biological Consequences After Irradiation.

    Science.gov (United States)

    Popov, Dmitri; Maliev, Vecheslav; Jones, Jeffrey

    "Alle Ding' sind Gift, und nichts ohn' Gift; allein die Dosis macht, daß ein Ding kein Gift ist." Paracelsus Philippus Aureolus Theophrastus Bombastus von Hohenheim. Key worlds: Apoptosis, Necrosis, Domains associated with Cell Death, Caspase (catalytic) Domains, Death Domains (DDs), Death Effector Domains (DEDs), Caspase-Associated Recruitment Domains (CARDs, BIR Domains (IAPs), Bcl-2 Homology (BH) Domains, death ligands - TRAIL (TNF-Related Apoptosis-Inducing Ligand), FasL (Fas Ligand), TNFalpha (Tumor Necrosis Factor alpha), Toll-like receptors (TLR), Systemic inflammatory response syndrome (SIRS), Toxic Multiple Organ Injury (TMOI), Toxic Multiple Organ Dysfunction Syndromes (TMODS), Toxic Multiple Organ Failure (TMOF), Anaphylatoxins, or complement peptides; membrane attack complex (MAC), ROS - Reactive Oxygen Species; ASMase, acid sphingomyelinase; Neurotoxins, Cytotoxins, Haemotoxins. Introduction: Radiation affects many cell structures, organelles and metabolic pathways. Different doses and types of radiation ( gamma-radiation, neutron, heavy ion radiation) progress to reversible and irreversible forms of cell injury. Consideration: Apoptosis and Necrosis, major forms of post-radiation cell death, can be initiated and modulated by programmed control and proceed by similar or different pathways.[Akadi et al.,1993, Dunlacht J., et al. 1999] Radiation induced cell death by triggering apoptosis pathways was described in many articles and supported by many scientists. [Rio et al. 2002, Rakesh et al. 1997.] However some authors present results that two distinct pathways can initiate or apoptotic or necrotic responses: the death receptors and mitochondrial pathways.

  12. Light ions radiobiological effects on human tumoral cells: measurements modelling and application to hadron-therapy; Mesures et modelisation des effets radiobiologiques des ions legers sur des cellules tumorales humaines: application a l'hadrontherapie

    Energy Technology Data Exchange (ETDEWEB)

    Jalade, P

    2005-11-15

    In classical radiotherapy, the characteristics of photons interactions undergo limits for the treatment of radioresistant and not well located tumours. Pioneering treatments of patients at the Lawrence Laboratory at Berkeley has demonstrated two advantages of hadrons beams: the Relative Biologic Effect (the RBE) and the ballistic of the beams. Since 1994, the clinical centre at Chiba, has demonstrated successfully the applicability of the method. A physics group, managed by G. Kraft, at Darmstadt in Germany, has underlined the advantages of carbon beams. An European pool, called ENGIGHT (European Network for LIGHt ion Therapy) has been created in which the French ETOILE project appeared. The purpose of the thesis concerns measurements and models of 'in vitro' human cells survival. In the first part, the nowadays situation in particles interactions, tracks and cells structures and radiobiology is presented here. The second is devoted to the models based on the beam tracks and localization of the physical dose. Discussion of sensitivity to various parameters of the model has been realized with the help of numerical simulations. Finally the predictions of the improved model has been compared to experimental irradiations of human cells with argon and carbon beams of the GANIL machine. Conclusion of such study shows the performance and limits of a local model for predicting the radiobiological efficiency of light ions in hadron-therapy. (author)

  13. The required number of treatment imaging days for an effective off-line correction of systematic errors in conformal radiotherapy of prostate cancer -- a radiobiological analysis

    International Nuclear Information System (INIS)

    Background and purpose: To use radiobiological modelling to estimate the number of initial days of treatment imaging required to gain most of the benefit from off-line correction of systematic errors in the conformal radiation therapy of prostate cancer. Materials and methods: Treatment plans based on the anatomical information of a representative patient were generated assuming that the patient is treated with a multi leaf collimator (MLC) four-field technique and a total isocentre dose of 72 Gy delivered in 36 daily fractions. Target position variations between fractions were simulated from standard deviations of measured data found in the literature. Off-line correction of systematic errors was assumed to be performed only once based on the measured errors during the initial days of treatment. The tumour control probability (TCP) was calculated using the Webb and Nahum model. Results: Simulation of daily variations in the target position predicted a marked reduction in TCP if the planning target volume (PTV) margin was smaller than 4 mm (TCP decreased by 3.4% for 2 mm margin). The systematic components of target position variations had greater effect on the TCP than the random components. Off-line correction of estimated systematic errors reduced the decrease in TCP due to target daily displacements, nevertheless, the resulting TCP levels for small margins were still less than the TCP level obtained with the use of an adequate PTV margin of ∼10 mm. The magnitude of gain in TCP expected from the correction depended on the number of treatment imaging days used for the correction and the PTV margin applied. Gains of 2.5% in TCP were estimated from correction of systematic errors performed after 6 initial days of treatment imaging for a 2 mm PTV margin. The effect of various possible magnitudes of systematic and random components on the gain in TCP expected from correction and on the number of imaging days required was also investigated. Conclusions: Daily

  14. Radiobiological restrictions and tolerance doses of repeated single-fraction hdr-irradiation of intersecting small liver volumes for recurrent hepatic metastases

    International Nuclear Information System (INIS)

    To assess radiobiological restrictions and tolerance doses as well as other toxic effects derived from repeated applications of single-fraction high dose rate irradiation of small liver volumes in clinical practice. Twenty patients with liver metastases were treated repeatedly (2 - 4 times) at identical or intersecting locations by CT-guided interstitial brachytherapy with varying time intervals. Magnetic resonance imaging using the hepatocyte selective contrast media Gd-BOPTA was performed before and after treatment to determine the volume of hepatocyte function loss (called pseudolesion), and the last acquired MRI data set was merged with the dose distributions of all administered brachytherapies. We calculated the BED (biologically equivalent dose for a single dose d = 2 Gy) for different α/β values (2, 3, 10, 20, 100) based on the linear-quadratic model and estimated the tolerance dose for liver parenchyma D90 as the BED exposing 90% of the pseudolesion in MRI. The tolerance doses D90 after repeated brachytherapy sessions were found between 22 - 24 Gy and proved only slightly dependent on α/β in the clinically relevant range of α/β = 2 - 10 Gy. Variance analysis showed a significant dependency of D90 with respect to the intervals between the first irradiation and the MRI control (p < 0.05), and to the number of interventions. In addition, we observed a significant inverse correlation (p = 0.037) between D90 and the pseudolesion's volume. No symptoms of liver dysfunction or other toxic effects such as abscess formation occurred during the follow-up time, neither acute nor on the long-term. Inactivation of liver parenchyma occurs at a BED of approx. 22 - 24 Gy corresponding to a single dose of ~10 Gy (α/β ~ 5 Gy). This tolerance dose is consistent with the large potential to treat oligotopic and/or recurrent liver metastases by CT-guided HDR brachytherapy without radiation-induced liver disease (RILD). Repeated small volume irradiation may be applied

  15. The study of tumoral, radiobiological, and general health factors that influence results and complications in a series of 448 oral tongue carcinomas treated exclusively by irradiation

    International Nuclear Information System (INIS)

    The aim was to study the different factors that influence the results and complications in a series of 448 carcinomas of the oral tongue treated from January 31, 1972 to December 31, 1986, by brachytherapy(Br)±neck dissection (181 cases) or combination of external beam irradiation and brachytherapy (EBI + Br) (267 cases). The patients distribution was: 125 T1, 186 T2, 128 T3, 9 T4Tx, 78% NO, and 22% N+. The authors used the guide gutter or plastic tubes technique (Paris system dosimetry). Results at 5 and 10 years are: local control 68% and 64%, locoregional control 58% and 53%, specific survival 45% and 39%, and overall survival 44% and 27%. In the unvariate analysis for local control (LC) and overall survival (OS), they considered the tumoral factors. At 5 years, the LC for T1, T2, T3, are 93%, 65%, and 49%, and the OS 69%, 41%, and 25%, respectively. The lesions of the undersurface of the tongue have a better LC (77%) than other localizations (64%). For general factors, the index of general health condition, age, and sex were not significant for LC, but proved significant for OS. Significant radiobiological factors: the safety margin (expressed by the ratio treated surface on tumoral surface ≥1.2) is significant for LC and OS. This is the same if the interval between EBI and Br is ≤ 20 days. Neither the dose rate, the spacing between the sources, the total dose, nor Br dose were significant, but the last two were adapted according to the infiltration. In the univariate study for grade 2 and 3 complications (tissue and bone), the surface treated (>12 cm2), and the dose rate >0.7 Gy/h were significant. The multivariate study showed that the small size of the lesion is the most important factor for local control, with brachytherapy alone for T1T2NO and the number of days between EBI and brachytherapy ≤20 days. For complications, the most important factors are the total dose >80 Gy and a treated surface >12 cm2. 37 refs., 1 fig., 5 tabs

  16. Roentgenology, radiology, radiobiology. 7. national congress on roentgenology, radiology, radiobiology

    International Nuclear Information System (INIS)

    339 abstracts of papers read at the congress are presented. They deal with the application of the conventional and modern diagnostic techniques like biomedical radiography, computerized tomography, ultrasonography, NMR imaging, DSA; radiotherapy; radiation hygiene and radiology. Some investigations concerning Kozloduj-NPP environment and post-Chernobyl impact on Bulgarian population are included as well. (I.M.)

  17. Radiobiological basis of radiation hygiene

    International Nuclear Information System (INIS)

    After a short introduction on radiation sources and population doses, the early and late effects of ionizing radiations on man are surveyed with reference to dose dependence. Extrapolation from known data on cancerogenesis by 50 rad or higher, to lower doses is possible, and recommended by ICRP. (Auth.)

  18. Geometric domains in cellular radiobiology

    International Nuclear Information System (INIS)

    A joint consideration of experimental findings and microdosimetric facts leads to the conclusion that the biological effects of ionizing radiations are determined by local concentration of absorbed energy at two types of sites that differ greatly in magnitude. They are of the scale of nanometres in primary DNA damage, and of micrometres in the especially deleterious combinations of damaged DNA fragments. Both kinds depend on LET; however, at the nanometre level the dependence is much smaller. Depending on the relative contribution of the two types, the RBE values for observed biological effects can vary considerably but they may be assumed to be larger for cell transformation than for cell killing. (author)

  19. Optimal fractionation from radiobiological view

    International Nuclear Information System (INIS)

    Not only in animal experiments but also from analyses of clinical data important knowledge could be obtained in recent years, that deal with the course of biological processes in tumor and normal tissue during fractionated irradiation. Relevant are differences in the capacity for recovery from sublethal radiation injury and in repopulation. Chronically reacting normal tissues show a clearly higher repair capacity than tumors, that can be used for hyperfractionation with reduced single dosis. However, strong attention must be given to repairing time, that the selective benefit is not endangered by incomplete recovery. On the other side clinical analyses have confirmed that the stem cell repopulation - going on in several tumor types, so e.g. in squamous cell carcinomas, during the time of conventional treatment - can make a considerable contribution to radioresistance. The actual level of knowledge justifies further clinical experiments with unconventional fractionation, especially with accelerated hyperfractionation. (author)

  20. Radiobiological ideas and radiotherapeutic practice

    International Nuclear Information System (INIS)

    A review lecture covering the following topics: oxygen effect; radiotherapy in hyperbaric oxygen; low dose rate photon irradiation; densely ionizing radiations; hyperthermia; hypoxic cell sensitizers; fractionated radiotherapy; and rationale and methodology of prospective concomitant controlled clinical trials. (author)

  1. Nevada Offsites Long-Term Hydrologic Monitoring Program

    International Nuclear Information System (INIS)

    The U.S. Department of Energy (DOE) Office of Legacy Management has long-term stewardship responsibility for DoE's Nevada Offsites Project. The Nevada Offsites consist of eight sites, outside the boundaries of the Nevada Test Site, where underground nuclear tests were conducted between 1961 and 1973. The eight Nevada Offsites are Amchitka (Alaska), Shoal and Central Nevada Test Area (Nevada), Rio Blanco and Rulison (Colorado), Gasbuggy and Gnome-Coach (New Mexico), and Salmon (Mississippi). The underground tests resulted in the release of multiple radionuclides to the detonation zone (cavity, chimney, and nuclear-fractured region); however, tritium is the most likely contaminant to migrate significant distances from the detonation zone because of its occurrence both as tritiated liquid water, which moves with ground water, and as tritiated water vapor. The U.S. Environmental Protection Agency has conducted environmental sampling and long-term monitoring for tritium and other radionuclides since 1972 at the Nevada Offsites under the Long-Term Hydrologic Monitoring Program (LTHMP). The objectives of the monitoring were to detect denotation-related radionuclides, track the fate and transport of other constituents, ensure public safety, inform the public and the news media, and document compliance with state and federal regulations. By and large, the LTHMP has achieved its objectives, because monitoring results have shown that areas outside the withdrawn lands are unaffected by the underground nuclear detonations. The past two decades have witnessed a gradual change in land use near some of the Nevada Offsites locations. In Colorado and New Mexico, these changes have included increasing population and increased extraction of natural gas near the detonation sites. In Nevada, there is a growing interest in tapping the vast ground water reserves that are contained in the rural inter-mountain valleys and piping the water to areas where it can be put to beneficial use

  2. American Society for Radiation Oncology (ASTRO) Survey of Radiation Biology Educators in U.S. and Canadian Radiation Oncology Residency Programs

    International Nuclear Information System (INIS)

    Purpose: To obtain, in a survey-based study, detailed information on the faculty currently responsible for teaching radiation biology courses to radiation oncology residents in the United States and Canada. Methods and Materials: In March-December 2007 a survey questionnaire was sent to faculty having primary responsibility for teaching radiation biology to residents in 93 radiation oncology residency programs in the United States and Canada. Results: The responses to this survey document the aging of the faculty who have primary responsibility for teaching radiation biology to radiation oncology residents. The survey found a dramatic decline with time in the percentage of educators whose graduate training was in radiation biology. A significant number of the educators responsible for teaching radiation biology were not fully acquainted with the radiation sciences, either through training or practical application. In addition, many were unfamiliar with some of the organizations setting policies and requirements for resident education. Freely available tools, such as the American Society for Radiation Oncology (ASTRO) Radiation and Cancer Biology Practice Examination and Study Guides, were widely used by residents and educators. Consolidation of resident courses or use of a national radiation biology review course was viewed as unlikely by most programs. Conclusions: A high priority should be given to the development of comprehensive teaching tools to assist those individuals who have responsibility for teaching radiation biology courses but who do not have an extensive background in critical areas of radiobiology related to radiation oncology. These findings also suggest a need for new graduate programs in radiobiology.

  3. Space Radiation Program Element Tissue Sharing Forum

    Science.gov (United States)

    Wu, H.; Mayeaux, B M.; Huff, J. L.; Simonsen, L. C.

    2016-01-01

    Over the years, a large number of animal experiments have been conducted at the NASA Space Radiation Laboratory and other facilities under the support of the NASA Space Radiation Program Element (SRPE). Studies using rodents and other animal species to address the space radiation risks will remain a significant portion of the research portfolio of the Element. In order to maximize scientific return of the animal studies, the SRPE has recently released the Space Radiation Tissue Sharing Forum. The Forum provides access to an inventory of investigator-stored tissue samples and enables both NASA SRPE members and NASA-funded investigators to exchange information regarding stored and future radiobiological tissues available for sharing. Registered users may review online data of available tissues, inquire about tissues posted, or request tissues for an upcoming study using an online form. Investigators who have upcoming sacrifices are also encouraged to post the availability of samples using the discussion forum. A brief demo of the forum will be given during the presentation

  4. The Nasa space radiation school, an excellent training in radiobiology and space radiation protection; La NASA space radiation summer school, une formation d'excellence en radiobiologie et radioprotection spatiale

    Energy Technology Data Exchange (ETDEWEB)

    Vogin, G. [Centre Alexis-Vautrin, 54 - Nancy (France)

    2009-10-15

    The astronauts have to spend more time in space and the colonization of the moon and Mars are in the cross hairs of international agencies. The cosmic radiation from which we are protected on ground by atmosphere and by the terrestrial magnetosphere (.4 mSv/year according to Who) become really threatening since 20 km altitude, delivering an average radiation dose of a therapeutic kind to astronauts with peaks related to solar events. It is composed in majority of hadrons: protons (85%) and heavy ions (13%), but also photons (2%) of high energy (GeV/n)). the incurred risks are multiple: early ones(cataract, central nervous system damages, whole body irradiation) but especially delayed ones (carcinogenesis). The astronauts radiation protection turns poor and the rate of death risk by cancer returning from a mission on Mars has been estimated at 5%. The Nasa created in 2004 a summer school aiming to awareness young researchers to the space radiobiology specificities. Areas concerned as follow: radioinduced DNA damage and repair, cell cycle, apoptosis, bystander effect, genome instability, neuro degeneration, delayed effects and carcinogenesis in relation with radiation exposure. (N.C.)

  5. Program specialization

    CERN Document Server

    Marlet, Renaud

    2013-01-01

    This book presents the principles and techniques of program specialization - a general method to make programs faster (and possibly smaller) when some inputs can be known in advance. As an illustration, it describes the architecture of Tempo, an offline program specializer for C that can also specialize code at runtime, and provides figures for concrete applications in various domains. Technical details address issues related to program analysis precision, value reification, incomplete program specialization, strategies to exploit specialized program, incremental specialization, and data speci

  6. Inexact Programming

    OpenAIRE

    Mahmood, Muhammad Yasir

    2012-01-01

    Two types of fuzzy linear programming i.e. fuzzy number linear programming and interval number linear programming are used for optimization problems. In interval form of linear programming we convert the inequalities from the feasible region, containing intervals as coefficients, to two groups of inequalities characterized by real, exact coefficients values. Then classical programming has been used to achieve an optimal solution in the feasible region. In fuzzy number linear programming, α‐cu...

  7. Comparative dosimetric and radiobiological assessment among a nonstandard RapidArc, standard RapidArc, classical intensity-modulated radiotherapy, and 3D brachytherapy for the treatment of the vaginal vault in patients affected by gynecologic cancer

    Energy Technology Data Exchange (ETDEWEB)

    Pedicini, Piernicola, E-mail: ppiern@libero.it [Service of Medical Physics, IRCCS Regional Cancer Hospital (C.R.O.B.), Rionero in Vulture (Italy); Caivano, Rocchina [Service of Medical Physics, IRCCS Regional Cancer Hospital (C.R.O.B.), Rionero in Vulture (Italy); Fiorentino, Alba [U.O. of Radiotherapy, IRCCS Regional Cancer Hospital (C.R.O.B.), Rionero in Vulture (Italy); Strigari, Lidia [Laboratory of Medical Physics and Expert Systems, Regina Elena National Cancer Institute, Rome (Italy); Califano, Giorgia [Service of Medical Physics, IRCCS Regional Cancer Hospital (C.R.O.B.), Rionero in Vulture (Italy); Barbieri, Viviana; Sanpaolo, Piero; Castaldo, Giovanni [U.O. of Radiotherapy, IRCCS Regional Cancer Hospital (C.R.O.B.), Rionero in Vulture (Italy); Benassi, Marcello [Service of Medical Physics, Scientific Institute of Tumors of Romagna IRST, Meldola (Italy); Fusco, Vincenzo [U.O. of Radiotherapy, IRCCS Regional Cancer Hospital (C.R.O.B.), Rionero in Vulture (Italy)

    2012-01-01

    To evaluate a nonstandard RapidArc (RA) modality as alternative to high-dose-rate brachytherapy (HDR-BRT) or IMRT treatments of the vaginal vault in patients with gynecological cancer (GC). Nonstandard (with vaginal applicator) and standard (without vaginal applicator) RapidArc plans for 27 women with GC were developed to compare with HDR-BRT and IMRT. Dosimetric and radiobiological comparison were performed by means of dose-volume histogram and equivalent uniform dose (EUD) for planning target volume (PTV) and organs at risk (OARs). In addition, the integral dose and the overall treatment times were evaluated. RA, as well as IMRT, results in a high uniform dose on PTV compared with HDR-BRT. However, the average of EUD for HDR-BRT was significantly higher than those with RA and IMRT. With respect to the OARs, standard RA was equivalent of IMRT but inferior to HDR-BRT. Furthermore, nonstandard RA was comparable with IMRT for bladder and sigmoid and better than HDR-BRT for the rectum because of a significant reduction of d{sub 2cc}, d{sub 1cc}, and d{sub max} (p < 0.01). Integral doses were always higher than HDR-BRT, although the values were very low. Delivery times were about the same and more than double for HDR-BRT compared with IMRT and RA, respectively. In conclusion, the boost of dose on vaginal vault in patients affected by GC delivered by a nonstandard RA technique was a reasonable alternative to the conventional HDR-BRT because of a reduction of delivery time and rectal dose at substantial comparable doses for the bladder and sigmoid. However HDR-BRT provides better performance in terms of PTV coverage as evidenced by a greater EUD.

  8. SU-E-T-480: Radiobiological Dose Comparison of Single Fraction SRS, Multi-Fraction SRT and Multi-Stage SRS of Large Target Volumes Using the Linear-Quadratic Formula

    Energy Technology Data Exchange (ETDEWEB)

    Ding, C; Hrycushko, B; Jiang, S; Meyer, J; Timmerman, R [UT Southwestern Medical Center, Dallas, TX (United States)

    2014-06-01

    Purpose: To compare the radiobiological effect on large tumors and surrounding normal tissues from single fraction SRS, multi-fractionated SRT, and multi-staged SRS treatment. Methods: An anthropomorphic head phantom with a centrally located large volume target (18.2 cm{sup 3}) was scanned using a 16 slice large bore CT simulator. Scans were imported to the Multiplan treatment planning system where a total prescription dose of 20Gy was used for a single, three staged and three fractionated treatment. Cyber Knife treatment plans were inversely optimized for the target volume to achieve at least 95% coverage of the prescription dose. For the multistage plan, the target was segmented into three subtargets having similar volume and shape. Staged plans for individual subtargets were generated based on a planning technique where the beam MUs of the original plan on the total target volume are changed by weighting the MUs based on projected beam lengths within each subtarget. Dose matrices for each plan were export in DICOM format and used to calculate equivalent dose distributions in 2Gy fractions using an alpha beta ratio of 10 for the target and 3 for normal tissue. Results: Singe fraction SRS, multi-stage plan and multi-fractionated SRT plans had an average 2Gy dose equivalent to the target of 62.89Gy, 37.91Gy and 33.68Gy, respectively. The normal tissue within 12Gy physical dose region had an average 2Gy dose equivalent of 29.55Gy, 16.08Gy and 13.93Gy, respectively. Conclusion: The single fraction SRS plan had the largest predicted biological effect for the target and the surrounding normal tissue. The multi-stage treatment provided for a more potent biologically effect on target compared to the multi-fraction SRT treatments with less biological normal tissue than single-fraction SRS treatment.

  9. Programs To Aid FORTRAN Programming

    Science.gov (United States)

    Ragosta, Arthur E.

    1987-01-01

    Program-development time decreased while program quality increased. FORTRAN Programming Tools are series of programming tools used to support development and maintenance of FORTRAN 77 source codes. Included are debugging aid, central-processing-unit time-monitoring program, source-code maintenance aids, print utilities, and library of useful, well-documented programs. Tools assist in reducing development time and encouraging high-quality programming. Although intended primarily for FORTRAN programmers, some tools used on data files and other programming languages. Written in FORTRAN 77.

  10. A follow-up study program for persons irradiated in radiation accidents

    International Nuclear Information System (INIS)

    Clinical and epidemiologic follow-up studies of survivors of radiation accidents are a major part of the program of the Radiation Emergency Assistance Center and Training Site (REAC/TS) in Oak Ridge, Tennessee, where training is provided for physicians and paramedical staff concerned with radiation-accident victims. Guidelines have been developed for clinicians and epidemiologists to do follow-up studies after accidental exposures. The human radiobiological data so obtained are used to improve clinical care and emergency planning in nuclear-energy production. Other aims of these studies are to provide the best prophylactic and anticipatory care for possible late radiation effects, and to continually upgrade radiobiologic risk estimates by epidemiologic investigations. Routine annual clinical follow-up studies are recommended for those survivors who were severely injured, and others who showed clinical or laboratory evidence of the acute radiation syndrome. The extent and protocol for medical examinations will be described. In industrial plants located in the United States where annual physical examinations are routine, medical results obtained about the status of such persons are reported to REAC/TS. Persons involved but not seriously exposed in radiation accidents are contacted annually by phone or letter to ascertain their whereabouts and health status for epidemiologic data collection. Dosimetric guidelines categorizing the follow-up groups will be defined. These are related to total-body exposure levels, extent of local exposures, and residual body and lung burdens of transuranic elements. The follow-up studies are continued for life. The records are deposited in a centralized national radiation-accident registry in REAC/TS where the information is available to clinicians, radiobiologists, and epidemiologists. (author)

  11. Quasiconvex Programming

    OpenAIRE

    Eppstein, David

    2004-01-01

    We define quasiconvex programming, a form of generalized linear programming in which one seeks the point minimizing the pointwise maximum of a collection of quasiconvex functions. We survey algorithms for solving quasiconvex programs either numerically or via generalizations of the dual simplex method from linear programming, and describe varied applications of this geometric optimization technique in meshing, scientific computation, information visualization, automated algorithm analysis, an...

  12. Effective Programming

    DEFF Research Database (Denmark)

    Frost, Jacob

    To investigate the use of VTLoE as a basis for formal derivation of functional programs with effects. As a part of the process, a number of issues central to effective formal programming are considered. In particular it is considered how to develop a proof system suitable for pratical reasoning......, how to implement this system in the generic proof assistant Isabelle and finally how to apply the logic and the implementation to programming....

  13. Program Fullerene

    DEFF Research Database (Denmark)

    Wirz, Lukas; Peter, Schwerdtfeger,; Avery, James Emil

    2013-01-01

    Fullerene (Version 4.4), is a general purpose open-source program that can generate any fullerene isomer, perform topological and graph theoretical analysis, as well as calculate a number of physical and chemical properties. The program creates symmetric planar drawings of the fullerene graph......-Fowler, and Brinkmann-Fowler vertex insertions. The program is written in standard Fortran and C++, and can easily be installed on a Linux or UNIX environment....

  14. Programming F#

    CERN Document Server

    Smith, Chris

    2009-01-01

    Why learn F#? This multi-paradigm language not only offers you an enormous productivity boost through functional programming, it also lets you develop applications using your existing object-oriented and imperative programming skills. With Programming F#, you'll quickly discover the many advantages of Microsoft's new language, which includes access to all the great tools and libraries of the .NET platform. Learn how to reap the benefits of functional programming for your next project -- whether it's quantitative computing, large-scale data exploration, or even a pursuit of your own. With th

  15. Programming Interactivity

    CERN Document Server

    Noble, Joshua

    2009-01-01

    Make cool stuff. If you're a designer or artist without a lot of programming experience, this book will teach you to work with 2D and 3D graphics, sound, physical interaction, and electronic circuitry to create all sorts of interesting and compelling experiences -- online and off. Programming Interactivity explains programming and electrical engineering basics, and introduces three freely available tools created specifically for artists and designers: Processing, a Java-based programming language and environment for building projects on the desktop, Web, or mobile phonesArduino, a system t

  16. Advances in radiobiological studies using a microbeam

    International Nuclear Information System (INIS)

    Recent developments in microbeam technology have made drastic improvements in particle delivery, focusing, image processing and precision to allow for rapid advances in our knowledge in radiation biology. The unequivocal demonstration that targeted cytoplasmic irradiation results in mutations in the nuclei of hit cells and the presence of non-targeted effects, all made possible using a charged particle microbeam, results in a paradigm shift in our basic understanding of the target theory and other radiation-induced low dose effects. The demonstration of a bystander effect in 3D human tissue and whole organisms have shown the potential relevance of the non-targeted response in human health. The demonstration of delayed mutations in the progeny of bystander cells suggest that genomic instability induced following ionizing radiation exposure is not dependent on direct damage to cell nucleus. The identification of specific signaling pathways provides mechanistic insight on the nature of the bystander process. (author)

  17. Development of radiobiological dentistry in Russia

    International Nuclear Information System (INIS)

    History of the radiological dentistry progress in Russia from the first report on the application of biomedical radiography techniques to dental practice in Russia in 1901 is briefly described. The first special X-ray room was open in 1921 in Petrograd. First scientific papers and guides on the radiological dentistry made their appearance. The second period in the development of Russian radiological dentistry was connected with the World War 2 and wounds of maxillo-facial wounds. Postwar time is characterized by application of the novel techniques, wide range of scientific researches in the radiological dentistry. The modern history of radiological dentistry began from 1983 due to computerized tomography used in case of malignant tumors of maxilla and nose cavity

  18. Radiobiological modelling with MarCell software

    Energy Technology Data Exchange (ETDEWEB)

    Hasan, J.S.; Jones, T.D.

    1996-10-01

    Jones introduced a bone marrow radiation cell kinetics model with great potential for application in the fields of health physics, radiation research, and medicine. However, until recently, only the model developers have been able to apply it because of the complex array of biological and physical assignments needed for evaluation of a particular radiation exposure protocol. The purpose of this article is to illustrate the use of MarCell (MARrow CELL Kinetics) software for MS-DOS, a user-friendly computer implementation of that mathematical model that allows almost anyone with an elementary knowledge of radiation physics and/or medical procedures to apply the model. A hands-on demonstration of the software will be given by guiding the user through evaluation of a medical total body irradiation protocol and a nuclear fallout scenario. A brief overview of the software is given in the Appendix.

  19. Radiobiology of the acute radiation syndrome

    International Nuclear Information System (INIS)

    Acute radiation syndrome or acute radiation sickness is classically subdivided into three sub syndromes: the hematopoietic, gastrointestinal and neurovascular syndrome but many other tissues can be damaged. The time course and severity of clinical signs and symptoms are a function of the overall body volume irradiated, the inhomogeneity of dose exposure, the particle type, the absorbed dose and the dose rate. Classical pathophysiology explain the failure of each of these organs and the timing of appearance of their signs and symptoms due to radiation-induced cytocidal effects of a great number of parenchymal cells of hierarchically organized tissues. Contemporaneously, many other radiation-induced effects has been described and all of them may lead to tissue injury with their corresponding signs and symptoms that can be expressed after short or long period of time. Radiation-induced multi-organ involvement is thought to be due to radiation-induced systemic inflammatory response mediated by released pro-inflammatory cytokines. (authors)

  20. Fast neutron dosimetry ip radiobiological experiment

    International Nuclear Information System (INIS)

    The distribution of absorbed dose in organs and tissues of animals and other biological ob ects irradiated with fast neutrons in WWR-M nuclear reactor is studied. The method of differential homogeneous ionization chambers suggested for the separate determination of neutron and γ-components of tissue dose, is used. To determine the value of tissue dose at this or that depth of the subject investigated, appropriate phanthoms and the technique of microcondensator chambers are used. Sources of errors of measurements are analyzed. The study of distribution of deep absorbed doses in tissue-equivalent phanthoms has permitted to make definite conclusions and recommendations relatively to optimum conditions of irradiation with fast neutrons of different biological objects

  1. Radiobiological speculations on therapeutic total body irradiation

    International Nuclear Information System (INIS)

    Unexpected total body irradiation (TBI) of human beings, involved in nuclear warfare or in accidents in nuclear reactors can be lethal. In the 1950s, bone marrow transplantation was discovered as a potentially life saving procedure after TBI in the dose range of 5.0 to 12.0 Gy. Since that time, deliberate or therapeutic TBI has been used to condition patients with a lethal bone marrow disorder for bone marrow replacement. The therapeutic ratio of TBI followed by bone marrow transplantation is small. Many potentially lethal complications can occur, such as acute TBI side effects, late TBI side effects or immunological complications of bone marrow transplantation such as graft versus host disease or graft rejection. The benefits of TBI and bone marrow transplantation are that they offer a chance for cure of previously lethal bone marrow disorders. The optimal parameters for TBI remain to be defined. The review discusses the current clinical and experimental animal data, as they relate to the future definition of less toxic TBI procedures with a better therapeutic ratio. Different TBI procedures are required for patients with malignant vs. non-malignant disorders or for patients with histoincompatible vs. histocompatible bone marrow donors.77 references

  2. Radiobiological modelling with MarCell software

    International Nuclear Information System (INIS)

    Jones introduced a bone marrow radiation cell kinetics model with great potential for application in the fields of health physics, radiation research, and medicine. However, until recently, only the model developers have been able to apply it because of the complex array of biological and physical assignments needed for evaluation of a particular radiation exposure protocol. The purpose of this article is to illustrate the use of MarCell (MARrow CELL Kinetics) software for MS-DOS, a user-friendly computer implementation of that mathematical model that allows almost anyone with an elementary knowledge of radiation physics and/or medical procedures to apply the model. A hands-on demonstration of the software will be given by guiding the user through evaluation of a medical total body irradiation protocol and a nuclear fallout scenario. A brief overview of the software is given in the Appendix

  3. Experimental radiotherapy and clinical radiobiology. Vol. 16

    International Nuclear Information System (INIS)

    The following topics were dealt with: DNA repair as therapeutical target in radiation therapy, biological imaging and tumor microenvironment, molecular factors of radiation therapy, molecular factors and modulation of the radiation reaction of normal tissues, experimental tumor therapy, EGFR inhibition, the endothel cell as primary target of radiation therapy, molecular and cellular foundations of the radiation biology of protons and ions. (HSI)

  4. Mobile communication. Radiobiology problems and danger evaluation

    International Nuclear Information System (INIS)

    The actual problem of the effect of mobile radio communication on the healths of cellular telephone users is discussed. Dosimetric data of the specific absorbed rate of electromagnetic field in a human head during cellular telephone using. Results of physiological, biochemical, clinical and physiological investigations of the effect of electromagnetic field of cellular telephones on the health stable of volunteers are analyzed. It is found out that MPL of power density for the user of cellular telephone is equal to 100 μW/cm2

  5. Radiobiological aspects of radiotherapy treatment planning

    International Nuclear Information System (INIS)

    The aim of an oncological treatment is to eradicate the tumor without inducing unacceptable side effects. The optimization of a dose distribution with external beams requires the selection of the radiation type and energy, the number of fields, their sizes and incidence angles of the beams and then the possible use of wedges or compensating filters. The goal of optimal treatment planning is to provide maximum tumor killing while sparing normal tissues as much as possible. New, more sophisticated planning systems, based on three dimensional dose distribution calculations, require simplified data interpretation techniques. Dose volume histograms represent a convenient and useful tool to summarize dose distribution information through the entire volume of a given anatomic structure and to quickly highlight characteristics such as dose uniformity and hot and cold spots. It is difficult however to choose among competing histograms concerning different organs when they cross one another. This paper discusses the development of a computerized treatment planning system in which dose volume histograms are used to estimate tumor control and normal tissue complication probabilities

  6. Cicop program

    International Nuclear Information System (INIS)

    It is described the input data for using in the Cicop computer code in the Honeywell Bull computer of CNEN. It is a program to prepare microscopic cross section library in a proper format to be directly used by the Citation program from the Macroscopic cross section and isotope concentration. (Author)

  7. BASIC Programming.

    Science.gov (United States)

    Jennings, Carol Ann

    Designed for use by both secondary- and postsecondary-level business teachers, this curriculum guide consists of 10 units of instructional materials dealing with Beginners All-Purpose Symbol Instruction Code (BASIC) programing. Topics of the individual lessons are numbering BASIC programs and using the PRINT, END, and REM statements; system…

  8. Choreographic Programming

    DEFF Research Database (Denmark)

    Montesi, Fabrizio

    , as they offer a concise view of the message flows enacted by a system. For this reason, in the last decade choreographies have been used in the development of programming languages, giving rise to a programming paradigm that in this dissertation we refer to as Choreographic Programming. Recent studies show...... endpoint described in a choreography can then be automatically generated, ensuring that such implementations are safe by construction. However, current formal models for choreographies do not deal with critical aspects of distributed programming, such as asynchrony, mobility, modularity, and multiparty...... sessions; it remains thus unclear whether choreographies can still guarantee safety when dealing with such nontrivial features. This PhD dissertation argues for the suitability of choreographic programming as a paradigm for the development of safe distributed systems. We proceed by investigating its...

  9. Studies of acute and chronic radiation injury at the Biological and Medical Research Division, Argonne National Laboratory, 1970-1992: The JANUS Program Survival and Pathology Data

    Energy Technology Data Exchange (ETDEWEB)

    Grahn, D.; Wright, B.J.; Carnes, B.A.; Williamson, F.S.; Fox, C.

    1995-02-01

    A research reactor for exclusive use in experimental radiobiology was designed and built at Argonne National Laboratory in the 1960`s. It was located in a special addition to Building 202, which housed the Division of Biological and Medical Research. Its location assured easy access for all users to the animal facilities, and it was also near the existing gamma-irradiation facilities. The water-cooled, heterogeneous 200-kW(th) reactor, named JANUS, became the focal point for a range of radiobiological studies gathered under the rubic of {open_quotes}the JANUS program{close_quotes}. The program ran from about 1969 to 1992 and included research at all levels of biological organization, from subcellular to organism. More than a dozen moderate- to large-scale studies with the B6CF{sub 1} mouse were carried out; these focused on the late effects of whole-body exposure to gamma rays or fission neutrons, in matching exposure regimes. In broad terms, these studies collected data on survival and on the pathology observed at death. A deliberate effort was made to establish the cause of death. This archieve describes these late-effects studies and their general findings. The database includes exposure parameters, time of death, and the gross pathology and histopathology in codified form. A series of appendices describes all pathology procedures and codes, treatment or irradiation codes, and the manner in which the data can be accessed in the ORACLE database management system. A series of tables also presents summaries of the individual experiments in terms of radiation quality, sample sizes at entry, mean survival times by sex, and number of gross pathology and histopathology records.

  10. Programming Python

    CERN Document Server

    Lutz, Mark

    2011-01-01

    If you've mastered Python's fundamentals, you're ready to start using it to get real work done. Programming Python will show you how, with in-depth tutorials on the language's primary application domains: system administration, GUIs, and the Web. You'll also explore how Python is used in databases, networking, front-end scripting layers, text processing, and more. This book focuses on commonly used tools and libraries to give you a comprehensive understanding of Python's many roles in practical, real-world programming. You'll learn language syntax and programming techniques in a clear and co

  11. NORD program

    International Nuclear Information System (INIS)

    A procedure of estimating the state of the WWER-1000 core power density on the basic of the in-core instrumentation system data is presented. A NORD program realizing this procedure in BASIC has been developed for on-line processing of experimental data. The program is designed for operation in dialog mode, has a service input-output unit and a unit for statistical processing of experimental results. The program makes it possible to evaluate quantitatively the differences of the power density fields obtained on the basis of readings taken from temperature control detectors and detectors of the neutron measuring channels. 5 refs.; 3 tabs

  12. Program overview

    International Nuclear Information System (INIS)

    The program overview describes the following resources and facilities; laser facilities, main laser room, target room, energy storage, laboratory area, building support systems, general plant project, and the new trailer complex

  13. [Mentoring program].

    Science.gov (United States)

    Watanabe, N

    2001-11-01

    Due to drastic changes in the business environment and prolonged recession, stress management practices in business organizations have been encountering two kinds of problems: budget cuts and difficulties in the delivery of services. The feasibility of mentoring programs to cope with these two problems is discussed. Through an extensive review of the literature, it becomes clear that mentoring programs have the following features and advantages; (1) One to one relationship between elder mentor and younger protégé has a favorable effect on the both mentor and protégé's mental health. (2) Formal mentoring programs are widely used in the U.S. for the prevention of juvenile delinquency, professional education, and human resource development in business settings. (3) Mentoring programs, in general, are practiced with the cooperation of kindred volunteers and professionals who monitor the mentor-protégé relationships. (4) Since a mentoring program utilizes a wide range of human resources in work organizations, it is able to overcome the "budget and delivery" problems. Further discussions are about the comparison with listener programs as well as the relationship with the total human resource management system. PMID:11802451

  14. 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)

  15. 8. International congress of the SBBN. Radiation in biosciences: research development and innovation. Program and abstracts

    International Nuclear Information System (INIS)

    The congress presents: pre-congress courses as Application of Cytometry of Flux in Radiobiology and Radiation Protection in Medical and Industrial Activities; thematic modules with plenary lectures and round tables such as Radioecology and Environmental Management, Advances in Image Diagnosis, Medical Physics and Quality Assurance in Diagnosis and Therapy, Advances in Radiobiology; poster sessions on Special Topics and Radiopharmacy and oral presentation of selected works on Radiotherapy, Radiation Protection and Radiopharmacy and exhibition of products and services

  16. Amchitka aquatic ecology studies, third quarter, January through March 1968: Progress report

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The objectives of the aquatic ecology study include an assessment of the fish and aquatic invertebrate populations in the streams and in the ponds throughout the...

  17. Integer programming

    CERN Document Server

    Conforti, Michele; Zambelli, Giacomo

    2014-01-01

    This book is an elegant and rigorous presentation of integer programming, exposing the subject’s mathematical depth and broad applicability. Special attention is given to the theory behind the algorithms used in state-of-the-art solvers. An abundance of concrete examples and exercises of both theoretical and real-world interest explore the wide range of applications and ramifications of the theory. Each chapter is accompanied by an expertly informed guide to the literature and special topics, rounding out the reader’s understanding and serving as a gateway to deeper study. Key topics include: formulations polyhedral theory cutting planes decomposition enumeration semidefinite relaxations Written by renowned experts in integer programming and combinatorial optimization, Integer Programming is destined to become an essential text in the field.

  18. Programming Algol

    CERN Document Server

    Malcolme-Lawes, D J

    2014-01-01

    Programming - ALGOL describes the basics of computer programming using Algol. Commands that could be added to Algol and could increase its scope are described, including multiplication and division and the use of brackets. The idea of labeling or naming a command is also explained, along with a command allowing two alternative results. Most of the important features of Algol syntax are discussed, and examples of compound statements (that is, sets of commands enclosed by a begin ... end command) are given.Comprised of 11 chapters, this book begins with an introduction to the digital computer an

  19. Programming Interactivity

    CERN Document Server

    Noble, Joshua

    2012-01-01

    Ready to create rich interactive experiences with your artwork, designs, or prototypes? This is the ideal place to start. With this hands-on guide, you'll explore several themes in interactive art and design-including 3D graphics, sound, physical interaction, computer vision, and geolocation-and learn the basic programming and electronics concepts you need to implement them. No previous experience is necessary. You'll get a complete introduction to three free tools created specifically for artists and designers: the Processing programming language, the Arduino microcontroller, and the openFr

  20. Studies of acute and chronic radiation injury at the Biological and Medical Research Division, Argonne National Laboratory, 1970-1992: The JANUS Program Survival and Pathology Data

    International Nuclear Information System (INIS)

    A research reactor for exclusive use in experimental radiobiology was designed and built at Argonne National Laboratory in the 1960's. It was located in a special addition to Building 202, which housed the Division of Biological and Medical Research. Its location assured easy access for all users to the animal facilities, and it was also near the existing gamma-irradiation facilities. The water-cooled, heterogeneous 200-kW(th) reactor, named JANUS, became the focal point for a range of radiobiological studies gathered under the rubic of open-quotes the JANUS programclose quotes. The program ran from about 1969 to 1992 and included research at all levels of biological organization, from subcellular to organism. More than a dozen moderate- to large-scale studies with the B6CF1 mouse were carried out; these focused on the late effects of whole-body exposure to gamma rays or fission neutrons, in matching exposure regimes. In broad terms, these studies collected data on survival and on the pathology observed at death. A deliberate effort was made to establish the cause of death. This archieve describes these late-effects studies and their general findings. The database includes exposure parameters, time of death, and the gross pathology and histopathology in codified form. A series of appendices describes all pathology procedures and codes, treatment or irradiation codes, and the manner in which the data can be accessed in the ORACLE database management system. A series of tables also presents summaries of the individual experiments in terms of radiation quality, sample sizes at entry, mean survival times by sex, and number of gross pathology and histopathology records

  1. SLED program

    International Nuclear Information System (INIS)

    A FORTRAN program is described which, for a given cavity and timing, yields all fields as a (piecewise) function of time, and which, for any mix of SLEDded and non-SLEDded klystrons of any given energy/klystron, yields the SLED operation parameters. The note explains the input and output parameters as they appear in the code output. 3 figures, 19 tables

  2. ORGEL program

    Energy Technology Data Exchange (ETDEWEB)

    none

    1963-09-01

    Parameter optimization studies for an ORGEL power plant are reported, and the ESSOR test reactor used in the program is described. Research at Ispra in reactor physics, technology, metallurgy, heat transfer, chemistry, and physical chemistry associated with ORGEL development is also summarized. (D.C.W.)

  3. First steps towards a fast-neutron therapy planning program

    Directory of Open Access Journals (Sweden)

    Garny Sylvia

    2011-11-01

    Full Text Available Abstract Background The Monte Carlo code GEANT4 was used to implement first steps towards a treatment planning program for fast-neutron therapy at the FRM II research reactor in Garching, Germany. Depth dose curves were calculated inside a water phantom using measured primary neutron and simulated primary photon spectra and compared with depth dose curves measured earlier. The calculations were performed with GEANT4 in two different ways, simulating a simple box geometry and splitting this box into millions of small voxels (this was done to validate the voxelisation procedure that was also used to voxelise the human body. Results In both cases, the dose distributions were very similar to those measured in the water phantom, up to a depth of 30 cm. In order to model the situation of patients treated at the FRM II MEDAPP therapy beamline for salivary gland tumors, a human voxel phantom was implemented in GEANT4 and irradiated with the implemented MEDAPP neutron and photon spectra. The 3D dose distribution calculated inside the head of the phantom was similar to the depth dose curves in the water phantom, with some differences that are explained by differences in elementary composition. The lateral dose distribution was studied at various depths. The calculated cumulative dose volume histograms for the voxel phantom show the exposure of organs at risk surrounding the tumor. Conclusions In order to minimize the dose to healthy tissue, a conformal treatment is necessary. This can only be accomplished with the help of an advanced treatment planning system like the one developed here. Although all calculations were done for absorbed dose only, any biological dose weighting can be implemented easily, to take into account the increased radiobiological effectiveness of neutrons compared to photons.

  4. First steps towards a fast-neutron therapy planning program

    International Nuclear Information System (INIS)

    The Monte Carlo code GEANT4 was used to implement first steps towards a treatment planning program for fast-neutron therapy at the FRM II research reactor in Garching, Germany. Depth dose curves were calculated inside a water phantom using measured primary neutron and simulated primary photon spectra and compared with depth dose curves measured earlier. The calculations were performed with GEANT4 in two different ways, simulating a simple box geometry and splitting this box into millions of small voxels (this was done to validate the voxelisation procedure that was also used to voxelise the human body). In both cases, the dose distributions were very similar to those measured in the water phantom, up to a depth of 30 cm. In order to model the situation of patients treated at the FRM II MEDAPP therapy beamline for salivary gland tumors, a human voxel phantom was implemented in GEANT4 and irradiated with the implemented MEDAPP neutron and photon spectra. The 3D dose distribution calculated inside the head of the phantom was similar to the depth dose curves in the water phantom, with some differences that are explained by differences in elementary composition. The lateral dose distribution was studied at various depths. The calculated cumulative dose volume histograms for the voxel phantom show the exposure of organs at risk surrounding the tumor. In order to minimize the dose to healthy tissue, a conformal treatment is necessary. This can only be accomplished with the help of an advanced treatment planning system like the one developed here. Although all calculations were done for absorbed dose only, any biological dose weighting can be implemented easily, to take into account the increased radiobiological effectiveness of neutrons compared to photons

  5. Program overview: Subsurface science program

    International Nuclear Information System (INIS)

    The OHER Subsurface Science Program is DOE's core basic research program concerned with subsoils and groundwater. These practices have resulted in contamination by mixtures of organic chemicals, inorganic chemicals, and radionuclides. A primary long-term goal is to provide a foundation of knowledge that will lead to the reduction of environmental risks and to cost-effective cleanup strategies. Since the Program was initiated in 1985, a substantial amount of research in hydrogeology, subsurface microbiology, and the geochemistry of organically complexed radionuclides has been completed, leading to a better understanding of contaminant transport in groundwater and to new insights into microbial distribution and function in the subsurface environments. The Subsurface Science Program focuses on achieving long-term scientific advances that will assist DOE in the following key areas: providing the scientific basis for innovative in situ remediation technologies that are based on a concept of decontamination through benign manipulation of natural systems; understanding the complex mechanisms and process interactions that occur in the subsurface; determining the influence of chemical and geochemical-microbial processes on co-contaminant mobility to reduce environmental risks; improving predictions of contaminant transport that draw on fundamental knowledge of contaminant behavior in the presence of physical and chemical heterogeneities to improve cleanup effectiveness and to predict environmental risks

  6. Constraint Programming versus Mathematical Programming

    DEFF Research Database (Denmark)

    Hansen, Jesper

    2003-01-01

    Constraint Logic Programming (CLP) is a relatively new technique from the 80's with origins in Computer Science and Artificial Intelligence. Lately, much research have been focused on ways of using CLP within the paradigm of Operations Research (OR) and vice versa. The purpose of this paper...

  7. Linear programming

    CERN Document Server

    Karloff, Howard

    1991-01-01

    To this reviewer’s knowledge, this is the first book accessible to the upper division undergraduate or beginning graduate student that surveys linear programming from the Simplex Method…via the Ellipsoid algorithm to Karmarkar’s algorithm. Moreover, its point of view is algorithmic and thus it provides both a history and a case history of work in complexity theory. The presentation is admirable; Karloff's style is informal (even humorous at times) without sacrificing anything necessary for understanding. Diagrams (including horizontal brackets that group terms) aid in providing clarity. The end-of-chapter notes are helpful...Recommended highly for acquisition, since it is not only a textbook, but can also be used for independent reading and study. —Choice Reviews The reader will be well served by reading the monograph from cover to cover. The author succeeds in providing a concise, readable, understandable introduction to modern linear programming. —Mathematics of Computing This is a textbook intend...

  8. Biological programming

    OpenAIRE

    Ramsden, Jeremy J.; Bándi, Gergely

    2010-01-01

    Biology offers a tremendous set of concepts that are potentially very powerfully usable for the software engineer, but they have been barely exploited hitherto. In this position paper we propose a fresh attempt to create the building blocks of a programming technology that could be as successful as life. A key guiding principle is to develop and make use of unambiguous definitions of the essential features of life.

  9. Program summary

    International Nuclear Information System (INIS)

    The operating, construction, and development activities of the Department of Energy in the areas of uranium enrichment are described. The DOE supplies the enrichment service through toll enrichment contracts with foreign and domestic utilities by enriching uranium supplied by the utility to the desired U-235 level. This role will continue well into the next century. In addition it provides enriched uranium for US Government needs and for R and D purposes. At the present time, almost all the world's capacity to produce enriched uranium uses the gaseous diffusion process. The United States built the first gaseous diffusion plant during World War II. Later this plant was expanded and two additional plants were built. There is presently a $1.5 billion improvement and uprating program near completion which will improve the plant efficiency and increase the total capacity of the three plants by 60 percent to 27.3 million SWU per year. The Administration's energy message in 1977 provided for a further expansion of this capacity by using gas centrifuge technology. The new gas centrifuge plant is being built near the existing GDP near Portsmouth, Ohio. The normal capacity of an 8 building process plant will be 13.2 million SWU per year. The first 2.2 million SWU of capacity is scheduled to be available in 1989. The remaining capacity will be added as needed to meet demand and the overall goal of the program. The goal of the Uranium Enrichment Program is to meet domestic, foreign, and US Government requirements for uranium enrichment services in an economical, reliable, safe and environmentally acceptable manner. To ensure accomplishment of this goal, the overall program is broken down into three areas of implementation; Enrichment Operations; Capacity Upgrading Operations; and Business Operations

  10. Ostomy Home Skills Program

    Medline Plus

    Full Text Available ... Standards News Cancer Cancer Programs Cancer Programs American Joint Committee on Cancer Cancer Advocacy Efforts Cancer Liaison ... Validation Programs Accredited Education Institutes CME Accreditation CME Joint Providership Program Program for Validation and Verification of ...

  11. Programming Pig

    CERN Document Server

    Gates, Alan

    2011-01-01

    This guide is an ideal learning tool and reference for Apache Pig, the open source engine for executing parallel data flows on Hadoop. With Pig, you can batch-process data without having to create a full-fledged application-making it easy for you to experiment with new datasets. Programming Pig introduces new users to Pig, and provides experienced users with comprehensive coverage on key features such as the Pig Latin scripting language, the Grunt shell, and User Defined Functions (UDFs) for extending Pig. If you need to analyze terabytes of data, this book shows you how to do it efficiently

  12. RADARSAT program

    Science.gov (United States)

    Mcnally, J.; Parashar, S.

    1993-01-01

    Work on the RADARSAT system is progressing towards the currently scheduled launch date of early 1995. The spacecraft bus and the Synthetic Aperture Radar (SAR) payload are at various stages of development. Requirements for the ground segment have been mostly established. The design of the ground elements such as the mission control facility and the SAR data processor is underway. The SAR applications development work is continuing and the chosen distributor, RADARSAT International Inc. (RSI) is making preparations to market RADARSAT data internationally. A plan for the follow-on to RADARSAT 1 is being finalized to ensure continuity of SAR data under the Radarsat program.

  13. Programming Razor

    CERN Document Server

    Chadwick, Jess

    2011-01-01

    Take Razor for a test drive and discover first hand how this scripting syntax simplifies the way you create dynamic, data-driven websites. With this concise guide, you'll work with Razor syntax by building example websites with Microsoft WebMatrix and ASP.NET MVC. You'll quickly learn how Razor lets you combine code and content in a fluid and expressive manner on Windows-based servers. Programming Razor also explores components of the Razor API, and shows you how Razor templates are turned into rendered HTML. By the end of this book, you'll be able to create Razor-based websites with custom

  14. Quantum Predicative Programming

    OpenAIRE

    Tafliovich, Anya; Hehner, E. C. R.

    2006-01-01

    The subject of this work is quantum predicative programming -- the study of developing of programs intended for execution on a quantum computer. We look at programming in the context of formal methods of program development, or programming methodology. Our work is based on probabilistic predicative programming, a recent generalisation of the well-established predicative programming. It supports the style of program development in which each programming step is proven correct as it is made. We...

  15. Telemedicine Program

    Science.gov (United States)

    1996-01-01

    Since the 1970s, NASA has been involved in the research and demonstration of telemedicine for its potential in the care of astronauts in flight and Earth-bound applications. A combination of NASA funding, expertise and off-the-shelf computer and networking systems made telemedicine possible for a medically underserved hospital in Texas. Through two-way audio/video relay, the program links pediatric oncology specialists at the University of Texas Health Science Center in San Antonio to South Texas Hospital in Harlingen, providing easier access and better care to children with cancer. Additionally, the hospital is receiving teleclinics on pediatric oncology nursing, family counseling and tuberculosis treatment. VTEL Corporation, Sprint, and the Healthcare Open Systems and Trials Consortium also contributed staff and hardware.

  16. Apollo Program

    Science.gov (United States)

    1963-01-01

    Construction of the track which runs in front of Model 2. Technicians work on Model 1, the 20-foot sphere. Project LOLA or Lunar Orbit and Landing Approach was a simulator built at Langley to study problems related to landing on the lunar surface. It was a complex project that cost nearly $2 million dollars. James Hansen wrote: 'This simulator was designed to provide a pilot with a detailed visual encounter with the lunar surface; the machine consisted primarily of a cockpit, a closed-circuit TV system, and four large murals or scale models representing portions of the lunar surface as seen from various altitudes. The pilot in the cockpit moved along a track past these murals which would accustom him to the visual cues for controlling a spacecraft in the vicinity of the moon. Unfortunately, such a simulation--although great fun and quite aesthetic--was not helpful because flight in lunar orbit posed no special problems other than the rendezvous with the LEM, which the device did not simulate. Not long after the end of Apollo, the expensive machine was dismantled.' (p. 379) Ellis J. White wrote in his paper 'Discussion of Three Typical Langley Research Center Simulation Programs,' 'The model system is designed so that a television camera is mounted on a camera boom on each transport cart and each cart system is shared by two models. The cart's travel along the tracks represents longitudinal motion along the plane of a nominal orbit, vertical travel of the camera boom represents latitude on out-of-plane travel, and horizontal travel of the camera boom represents altitude changes.' Published in James R. Hansen, Spaceflight Revolution: NASA Langley Research Center From Sputnik to Apollo, NASA SP-4308, p. 379; Ellis J. White, 'Discussion of Three Typical Langley Research Center Simulation Programs,' Paper presented at the Eastern Simulation Council (EAI's Princeton Computation Center), Princeton, NJ, October 20, 1966.

  17. Ostomy Home Skills Program

    Medline Plus

    Full Text Available ... Base Oncology Medical Home Accreditation Pilot Program Stereotactic Breast Biopsy Accreditation Program Cancer Program Staff Information Surgeon Specific Registry Surgeon Specific ...

  18. Annotated Answer Set Programming

    OpenAIRE

    Straccia, Umberto

    2005-01-01

    We present Annotated Answer Set Programming, that extends the ex pressive power of disjunctive logic programming with annotation terms, taken from the generalized annotated logic programming framework.

  19. Ostomy Home Skills Program

    Medline Plus

    Full Text Available ... Cancer Liaison Program Commission on Cancer National Cancer Data Base Oncology Medical Home Accreditation Pilot Program Stereotactic ... About Trauma Programs Stop the Bleed National Trauma Data Bank Trauma Quality Improvement Program Mentoring for Excellence ...

  20. Functional Python programming

    CERN Document Server

    Lott, Steven

    2015-01-01

    This book is for developers who want to use Python to write programs that lean heavily on functional programming design patterns. You should be comfortable with Python programming, but no knowledge of functional programming paradigms is needed.

  1. Human Reliability Program Overview

    Energy Technology Data Exchange (ETDEWEB)

    Bodin, Michael

    2012-09-25

    This presentation covers the high points of the Human Reliability Program, including certification/decertification, critical positions, due process, organizational structure, program components, personnel security, an overview of the US DOE reliability program, retirees and academia, and security program integration.

  2. Ostomy Home Skills Program

    Medline Plus

    Full Text Available ... Program for Breast Centers National Accreditation Program for Breast Centers About NAPBC Accreditation Education Patient Resources Center Resources NAPBC Standards News Cancer Cancer Programs Cancer Programs American Joint Committee on ...

  3. Stop smoking support programs

    Science.gov (United States)

    Smokeless tobacco - stop smoking programs; Stop smoking techniques; Smoking cessation programs; Smoking cessation techniques ... It is hard to quit smoking if you are acting alone. Smokers may have a ... of quitting with a support program. Stop smoking programs ...

  4. Ostomy Home Skills Program

    Medline Plus

    Full Text Available ... Program Outside Activities Member Communities Military Health System Strategic Partnership ACS Archives Board of Governors Advisory Councils Quality Programs Quality Programs Overview About Quality Programs ACS Leadership in Quality ACS Leadership in Quality Inspiring Quality ...

  5. Nonlinear Programming Method for Dynamic Programming

    OpenAIRE

    Yongyang Cai; Judd, Kenneth L; Lontzek, Thomas S.; Valentina Michelangeli; Che-Lin Su

    2013-01-01

    A nonlinear programming formulation is introduced to solve infinite horizon dynamic programming problems. This extends the linear approach to dynamic programming by using ideas from approximation theory to avoid inefficient discretization. Our numerical results show that this nonlinear programming method is efficient and accurate.

  6. Behavioral program synthesis with genetic programming

    CERN Document Server

    Krawiec, Krzysztof

    2016-01-01

    Genetic programming (GP) is a popular heuristic methodology of program synthesis with origins in evolutionary computation. In this generate-and-test approach, candidate programs are iteratively produced and evaluated. The latter involves running programs on tests, where they exhibit complex behaviors reflected in changes of variables, registers, or memory. That behavior not only ultimately determines program output, but may also reveal its `hidden qualities' and important characteristics of the considered synthesis problem. However, the conventional GP is oblivious to most of that information and usually cares only about the number of tests passed by a program. This `evaluation bottleneck' leaves search algorithm underinformed about the actual and potential qualities of candidate programs. This book proposes behavioral program synthesis, a conceptual framework that opens GP to detailed information on program behavior in order to make program synthesis more efficient. Several existing and novel mechanisms subs...

  7. Purely Functional Structured Programming

    OpenAIRE

    Obua, Steven

    2010-01-01

    The idea of functional programming has played a big role in shaping today's landscape of mainstream programming languages. Another concept that dominates the current programming style is Dijkstra's structured programming. Both concepts have been successfully married, for example in the programming language Scala. This paper proposes how the same can be achieved for structured programming and PURELY functional programming via the notion of LINEAR SCOPE. One advantage of this proposal is that m...

  8. System programming languages

    OpenAIRE

    Šmit, Matej

    2016-01-01

    Most operating systems are written in the C programming language. Similar is with system software, for example, device drivers, compilers, debuggers, disk checkers, etc. Recently some new programming languages emerged, which are supposed to be suitable for system programming. In this thesis we present programming languages D, Go, Nim and Rust. We defined the criteria which are important for deciding whether programming language is suitable for system programming. We examine programming langua...

  9. European MSc Programs in Nuclear Sciences-To meet the need of stakeholders

    International Nuclear Information System (INIS)

    A stakeholder needs assessment, carried out under the EU-EURAC and EU-ENEN-II projects, clearly showed that, at the European level, there are a significant and constant need for post-graduates with skills in radiochemistry, radioecology, radiation dosimetry and environmental modelling and a smaller, but still important, demand for radiobiologists and bio-modellers. Most of these needs are from government organizations. If only the nuclear industry is considered, then the largest demand is for radio chemists and radiation protection dosimetry experts. Given this spectrum of need and existing capacity in the areas of radiobiology it was concluded that the needs identified would be most efficiently met by three new degree programs: ·European MSc Radiation Protection, ·European MSc Analytical Radiochemistry, ·European MSc Radioecology. All three master programs would be developed using the framework provided by the Bologna Convention and the lecturing could be shared among specialist Scientists within a network of collaborating universities. Therefore, educational plans have been developed for the above MSc degrees. These plans envisage each degree comprising three modules that are common to all the degrees (3 x 10 ECTS credits), three specialist modules (3 x 10 ECTS credits) and a research project (1 x 60 ECTS credits). The courses should be aimed, not only to fill the identified European post-graduate education gap in radiological sciences, but also to provide a modular structure that is easily accessed by stakeholders for CPD training. It is anticipated that the European Masters will meet the academic training requirements of qualified experts', as defined by the European Commission and the IAEA. At the Norwegian University of Life Sciences (UMB) a pilot MSc in Radioecology has successfully been initiated in collaboration with UK and France.

  10. European MSc Programs in Nuclear Sciences - To meet the Need of Stakeholders

    International Nuclear Information System (INIS)

    A stakeholder needs assessment, carried out under the EU-EURAC and EU-ENEN II projects, clearly showed that, at the European level, there are a significant and constant need for post-graduates with skills in radiochemistry, radioecology, radiation dosimetry and environmental modelling and a smaller, but still important, demand for radiobiologists and bio-modellers. Most of these needs are from government organizations. If only the nuclear industry is considered, then the largest demand is for radiochemists and radiation protection dosimetrists. Given this spectrum of need and existing capacity in the areas of radiobiology it was concluded that the needs identified would be most efficiently met by three new degree programs: European MSc Radiation Protection European MSc Analytical Radiochemistry European MSc Radioecology. All three master programs would be developed using the framework provided by the Bologna Convention and the lecturing could be shared among specialist Scientists within a network of collaborating universities. Therefore, educational plans have been developed for the above MSc degrees. These plans envisage each degree comprising three modules that are common to all the degrees (3x10 ECTS credits), three specialist modules (3x10 ECTS credits) and a research project (1x60 ECTS credits). The courses should be aimed, not only to fill the identified European postgraduate education gap in radiological sciences, but also to provide a modular structure that is easily accessed by stakeholders for CPD training. It is anticipated that the European Masters will meet the academic training requirements of qualified 'experts', as defined by the European Commission and the IAEA. At the Norwegian University of Life Sciences (UMB) a pilot MSc in Radioecology has successfully been initiated in collaboration with UK and France.

  11. Structured Programming: An Introduction.

    Science.gov (United States)

    Moulton, Peter

    Designed for use by computer programming teachers, this booklet presents the concepts of structured programming and provides examples of how to implement this methodology, which provides a systematic way of organizing programs so that even large and complex programs are easier to understand and modify than unstructured programs. After a brief…

  12. Visual program simulation in introductory programming education

    OpenAIRE

    Sorva, Juha

    2012-01-01

    This thesis formulates and evaluates a pedagogical technique whose goal is to help beginners learn the basics of computer programming. The technique, visual program simulation (VPS), involves the learner in interactive simulations in which the learner takes on the role of the computer as the executor of a program. The student uses a given visualization of a so-called notional machine, an abstract computer, to illustrate what happens in memory as the computer processes the program. The purpose...

  13. Energy Technology Programs: program summaries for 1979

    Energy Technology Data Exchange (ETDEWEB)

    1979-12-01

    The Energy Technology Programs in the BNL Department of Energy and Environment cover a broad range of activities, namely: electrochemical research, chemical energy storage, chemical heat pumps, solar technology, fossil technology, catalytic systems development, space-conditioning technology, and technical support/program management. Summaries of the individual tasks associated with these activities along with publications, significant accomplishments, and program funding levels are presented.

  14. Ostomy Home Skills Program

    Medline Plus

    Full Text Available ... Accreditation Program for Breast Centers About NAPBC Accreditation Education Patient Resources Center Resources NAPBC Standards News Cancer ... Program for Hospitals Trauma Systems Consultation Program Trauma Education Publications and Posters Injury Prevention and Control Education ...

  15. Ostomy Home Skills Program

    Medline Plus

    Full Text Available ... Shop/Donate ( 0 ) Items American College of Surgeons Education Patients and Family Skills Programs Ostomy Home Skills Program Ostomy Home Skills Program Adult Ostomy Pediatric Ostomy Programa de Destrezas para manejo ...

  16. Ostomy Home Skills Program

    Medline Plus

    Full Text Available ... Member Chapter Leader RAS-ACS Leader YFA Leader Leadership & Advocacy Summit Operation Giving Back Operation Giving Back ... Programs Quality Programs Overview About Quality Programs ACS Leadership in Quality ACS Leadership in Quality Inspiring Quality ...

  17. Ostomy Home Skills Program

    Medline Plus

    Full Text Available ... ACS Insurance Programs ACS Discount Programs FACS Resources Career Connection Update Your Profile Scholarships, Fellowships, and Awards ... SSC Membership Directory Annual Meeting Mentorship Program Outside Activities Member Communities Military Health System Strategic Partnership ACS ...

  18. Masonry Program Standards.

    Science.gov (United States)

    Georgia Univ., Athens. Dept. of Vocational Education.

    This publication contains statewide standards for the masonry program in Georgia. The standards are divided into 12 categories: foundations (philosophy, purpose, goals, program objectives, availability, evaluation); admissions (admission requirements, provisional admission requirements, recruitment, evaluation and planning); program structure…

  19. Ostomy Home Skills Program

    Medline Plus

    Full Text Available ... Programs Educational Programs SESAP SESAP Sampler SRGS ACS Fundamentals of Surgery Curriculum Transition to Practice Program ACS/ ... Education Advanced Trauma Life Support Trauma Evaluation and Management Advanced Trauma Operative Management Rural Trauma Team Development ...

  20. Quantum Predicative Programming

    CERN Document Server

    Tafliovich, A; Tafliovich, Anya

    2006-01-01

    The subject of this work is quantum predicative programming -- the study of developing of programs intended for execution on a quantum computer. We look at programming in the context of formal methods of program development, or programming methodology. Our work is based on probabilistic predicative programming, a recent generalisation of the well-established predicative programming. It supports the style of program development in which each programming step is proven correct as it is made. We inherit the advantages of the theory, such as its generality, simple treatment of recursive programs, time and space complexity, and communication. Our theory of quantum programming provides tools to write both classical and quantum specifications, develop quantum programs that implement these specifications, and reason about their comparative time and space complexity all in the same framework.

  1. [Theme: Horticulture Programs.

    Science.gov (United States)

    Henderson, Jan; And Others

    1982-01-01

    A series of articles discusses requirements for optimum growth of horticulture education programs. Includes beginning a program, simulating working conditions, the need for mechanical skills, starting a business, and other areas to be considered for a successful horticultural program. (JOW)

  2. The impact on the radiobiological effect of lung squamous cancer cell line H520 with prolonged fraction delivery time%照射时间延长对肺鳞癌细胞株H520放射生物效应的影响

    Institute of Scientific and Technical Information of China (English)

    李磊; 孟玲楠; 高纯子; 林珊; 李瑛; 韩波

    2013-01-01

    目的观察常规剂量分割照射模式下单次照射时间延长对肺癌细胞系H520放射生物效应的影响.方法 (1)肺鳞癌细胞株H520离体培养,分组进行照射,利用克隆形成实验计算细胞存活比率(SF);(2)细胞给予总剂量为2Gy、4Gy、6Gy、8Gy的照射,并按照每日单次照射时间的不同分为A组(照射2分钟组)、B1组(照射10分钟组)、B2组(照射30分钟组).观察延长照射时间对肺鳞癌细胞株H520存活比率的影响.结果 伴随单次照射总时间的延长,实验细胞的存活比率逐渐提高,接受照射总剂量为8Gy的H520细胞株,A组细胞存活比率为1.9%;B1组和B2组存活比率分别为2.35%和3.42%.A组与B2组之间的差异具有统计学意义(P<0.05).结论 常规剂量分割模式下延长单次照射时间,显著降低了放射治疗对H520细胞的生物效应.%Objective The purpose of this study was to observe the radiobiological effects of lung squamous cancer cell line H520 irradiated over prolonged single fraction delivery time in the conventional dose fractionated mode. Methods (1)The H520 cell lines were cultured in vitro, and then irradiated by groups. Its survival fractions(SF)were calculated with standard clonogenic assays.( 2 )The total doses of 2 Gy,4 Gy,6 Gy,8 Gy were given to the cells,which were divided into groups by different single fraction delivery time:group A( group irradiated for 2 mins ),group Bl( group irradiated for 10 mins ),and group B2( group irradiated for 30 mins ),and observed the impact on the survival fractions of H520 cell line with prolonged fraction delivery time. Results The cell surviving fractions increased when the interfraction interval was longer. The values of SF 8 Gy were 1. 9% in group A,2.35% in group B1,and increased to 3. 42% in group B2 ,respectively. The difference between group A and group B2 was statistically significant(P<0.05 ). Conclusion The prolonged fraction delivery time would significantly decrease the

  3. Ostomy Home Skills Program

    Medline Plus

    Full Text Available ... Verification, Review, and Consultation Program for Hospitals Trauma Systems Consultation Program Trauma Education Publications and Posters Injury Prevention and Control Education ...

  4. Ostomy Home Skills Program

    Medline Plus

    Full Text Available ... Project Team Resources News Contact Us ACS NSQIP Pediatric ACS National Surgical Quality Improvement Program Pediatric ACS National Surgical Quality Improvement Program Pediatric About ...

  5. Research trends in radiobiology since 40 years. a new approach: the enzymatic repair function of DNA, internal factor in evolution of biological systems under irradiation; Etude des tendances des recherches en radiologie depuis 40 ans. Une nouvelle voie de recherche: la fonction de reparation enzymatique de l'ADN, facteur interne d'evolution des systemes biologiques sous rayonnement

    Energy Technology Data Exchange (ETDEWEB)

    Mouton, R. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1968-07-01

    In the first part of the report, the author attempts to draw an historical scheme of successive research working hypotheses in radiobiology since 1924. Less than a generation ago the effect of radiation exposure were viewed as being direct, immediate, irreparable and unmodifiable. Now it is generally accepted that radiation lesion can also be indirect, delayed, reparable and often modified with appropriate chemical or biochemical treatment. It was however in 1962-1964 that came the decisive breakthrough in radiobiology with the discovery that the cell possesses a natural active self-defense mechanism against whatever stress would affect the integrity of the genetic message contained in the DNA structure itself. The existence of what could be considered as a fourth DNA function i.e. self-repair by enzymatic action under genetic control-brings at least to radiobiology the missing molecular biology basis it needed to get out of its 'phenomenological night' after abandon of the generalization of Lea's theory through lack of experimental evidence. In the second part, which is a prospective one, the author tries to set an enlarged synthesis considering the possible role of DNA repair system not only in cell survival - in presence or absence of dose modifiers or mutagens - but also in the artificial and natural evolution of biological system exposed to sub-lethal doses of radiation. Most recent data from the literature fit well with what must be still considered as a general working hypothesis. Studies dealing with phenotypic and genotypic characters linked with the acquisition of gamma and UV radiation resistance in 'Escherichia coli K12' has been started by the author, in collaboration with O. Tremeau, in order to bring a new experimental contribution in this respect. (author) [French] Dans la premiere partie, l'auteur tente de retracer l'historique des hypotheses successives qui ont jalonne les avances de la radiobiologie depuis 1924

  6. Developing Parallel Programs

    OpenAIRE

    Ranjan Sen

    2012-01-01

    Parallel programming is an extension of sequential programming; today, it is becoming the mainstream paradigm in day-to-day information processing. Its aim is to build the fastest programs on parallel computers. The methodologies for developing a parallelprogram can be put into integrated frameworks. Development focuses on algorithm, languages, and how the program is deployed on the parallel computer.

  7. Ostomy Home Skills Program

    Medline Plus

    Full Text Available ... Quality Reporting System MOC Part 4 and Recertification Software and Registration SSR Webinars SSR Login Trauma Trauma Programs Trauma Programs About Trauma Programs Stop the Bleed National Trauma Data Bank Trauma Quality Improvement Program Mentoring for Excellence in Trauma Surgery Advanced ...

  8. National Transuranic Program Charter

    International Nuclear Information System (INIS)

    The National Transuranic Program Plan and Charter describes the functional elements of the National TRU Program, organizational relationships, programmatic responsibilities, division of work scope among the various DOE organizations that comprise the program, and program baselines against which overall progress will be measured. The charter defines the authorities and responsibilities of various organizations involved in the management of TRU waste throughout the DOE complex

  9. Laser Programs Highlights 1998

    Energy Technology Data Exchange (ETDEWEB)

    Lowdermilk, H.; Cassady, C.

    1999-12-01

    This report covers the following topics: Commentary; Laser Programs; Inertial Confinement Fusion/National Ignition Facility (ICF/NIF); Atomic Vapor Laser Isotope Separation (AVLIS); Laser Science and Technology (LS&T); Information Science and Technology Program (IS&T); Strategic Materials Applications Program (SMAP); Medical Technology Program (MTP) and Awards.

  10. [PIC Program Evaluation Forms.

    Science.gov (United States)

    Short, N. J.

    These 4 questionnaires are designed to elicit teacher and parent evaluations of the Prescriptive Instruction Center (PIC) program. Included are Teacher Evaluation of Program Effectiveness (14 items), M & M Evaluation of Program Implementation (methods and materials specialists; 11 items), Teacher Evaluation of Program Effectiveness--Case Study…

  11. The Cybernetic Writing Program.

    Science.gov (United States)

    Lowe, Kelly Fisher

    This paper looks at the role of a Writing Program Administrator, and applies the idea of a cybernetic system to the administration of the program. In this cybernetic model, the Writing Program Administrator (WPA) works as both a problem solver and problem causer, with the responsibility of keeping the program in proper balance. A cybernetic…

  12. Derivation of sorting programs

    Science.gov (United States)

    Varghese, Joseph; Loganantharaj, Rasiah

    1990-01-01

    Program synthesis for critical applications has become a viable alternative to program verification. Nested resolution and its extension are used to synthesize a set of sorting programs from their first order logic specifications. A set of sorting programs, such as, naive sort, merge sort, and insertion sort, were successfully synthesized starting from the same set of specifications.

  13. Light water reactor program

    Energy Technology Data Exchange (ETDEWEB)

    Franks, S.M.

    1994-12-31

    The US Department of Energy`s Light Water Reactor Program is outlined. The scope of the program consists of: design certification of evolutionary plants; design, development, and design certification of simplified passive plants; first-of-a-kind engineering to achieve commercial standardization; plant lifetime improvement; and advanced reactor severe accident program. These program activities of the Office of Nuclear Energy are discussed.

  14. C++ Programming Language

    Science.gov (United States)

    Shaykhian, Gholam Ali

    2007-01-01

    C++ Programming Language: The C++ seminar covers the fundamentals of C++ programming language. The C++ fundamentals are grouped into three parts where each part includes both concept and programming examples aimed at for hands-on practice. The first part covers the functional aspect of C++ programming language with emphasis on function parameters and efficient memory utilization. The second part covers the essential framework of C++ programming language, the object-oriented aspects. Information necessary to evaluate various features of object-oriented programming; including encapsulation, polymorphism and inheritance will be discussed. The last part of the seminar covers template and generic programming. Examples include both user defined and standard templates.

  15. Federal Wind Energy Program. Program summary. [USA

    Energy Technology Data Exchange (ETDEWEB)

    None

    1978-01-01

    The objective of the Federal Wind Energy Program is to accelerate the development of reliable and economically viable wind energy systems and enable the earliest possible commercialization of wind power. To achieve this objective for small and large wind systems requires advancing the technology, developing a sound industrial technology base, and addressing the non-technological issues which could deter the use of wind energy. This summary report outlines the projects being supported by the program through FY 1977 toward the achievement of these goals. It also outlines the program's general organization and specific program elements.

  16. Generating Consistent Program Tutorials

    DEFF Research Database (Denmark)

    Vestdam, Thomas

    In this paper we present a tool that supports construction of program tutorials. A program tutorial provides the reader with an understanding of an example program by interleaving fragments of source code and explaining text. An example program can for example illustrate how to use a library or a...... framework. We present a means for specifying the fragments of a program that are to be in-lined in the tutorial text. These in-line fragments are defined by addressing named syntactical elements, such as classes and methods, but it is also possible to address individual code lines by labeling them with...... source markers. The tool helps ensuring consistency between program tutorial and example programs by extracting fragments of source code based on the fragment specifications and by detecting when a program tutorial is addressing program fragments that do not exist. The program tutorials are presented as...

  17. Purely Functional Structured Programming

    CERN Document Server

    Obua, Steven

    2010-01-01

    The idea of functional programming has played a big role in shaping today's landscape of mainstream programming languages. Another concept that dominates the current programming style is Dijkstra's structured programming. Both concepts have been successfully married, for example in the programming language Scala. This paper proposes how the same can be achieved for structured programming and PURELY functional programming via the notion of LINEAR SCOPE. One advantage of this proposal is that mainstream programmers can reap the benefits of purely functional programming like easily exploitable parallelism while using familiar structured programming syntax and without knowing concepts like monads. A second advantage is that professional purely functional programmers can often avoid hard to read functional code by using structured programming syntax that is often easier to parse mentally.

  18. On Constraint Programming

    OpenAIRE

    Mathieu, Philippe; Keisu, Torbjörn

    1990-01-01

    This short note aims to present foundations for constraint logic programming. By logic programming, we understand in this paper the PROLOG paradigm. But it will be clear that we do reduce the problem to adding a new package to PROLOG. We argue that constraint logic programming should be defined as a new paradigm for programming: the LOGIC PROGRAMMING + SYMBOLIC COMPUTATION paradigm. Our system incorporates as a very basic, all the existing systems incorporating constraints i...

  19. Computer assisted mathematical programming

    OpenAIRE

    Lucas, CA; Mitra, G

    1987-01-01

    A Computer Assisted Mathematical Programming (Modelling) System (CAMPS) is described in this paper. The system uses program generator techniques for model creation and contrasts with earlier approaches which use a special purpose language to construct models. Thus no programming skill is required to formulate a model. In designing the system we have first analysed the salient components of the mathematical programming activity. A mathematical programming model is usually constructed by progre...

  20. Technology Commercialization Program 1991

    Energy Technology Data Exchange (ETDEWEB)

    1991-11-01

    This reference compilation describes the Technology Commercialization Program of the Department of Energy, Defense Programs. The compilation consists of two sections. Section 1, Plans and Procedures, describes the plans and procedures of the Defense Programs Technology Commercialization Program. The second section, Legislation and Policy, identifies legislation and policy related to the Program. The procedures for implementing statutory and regulatory requirements are evolving with time. This document will be periodically updated to reflect changes and new material.