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in subjects: "Radiology"

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Interface effects on dose distributions in irradiated media

It has long been recognized that nonuniformities in dose distributions may occur in the immediate vicinity of a boundary between two different media. Considerable work has been done to determine interface effects in media irradiated by photons or in media containing ..beta..- or ..cap alpha..-particle emitters. More recently interface effects have become of interest in additional problems, including pion radiotherapy and radiation effects in electronic microcircuits in space vehicles. These pro… more

Date: January 1, 1980

Creator: Wright, H.A.; Hamm, R.N. & Turner, J.E.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Dedicated medical ion accelerator design study. Final report

Results and conclusions are reported from a design study for a dedicated medical accelerator. Basing efforts on the current consensus regarding medical requirements, the resulting demands on accelerator and beam delivery systems were analyzed, and existing accelerator technology was reviewed to evaluate the feasibility of meeting these demands. This general analysis was augmented and verified by preparing detailed preliminary designs for sources of therapeutic beams of neutrons, protons and hea… more

Date: December 1, 1977

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Boron thermal/epithermal neutron capture therapy

The development of various particle beams for radiotherapy represents an attempt to improve dose distribution, and to provide high LET radiations which are less sensitive to ambient physical and radiobiological factors such as oxygen tension, cell cycle, and dose rate. In general, a compromise is necessary as effective RBE is reduced in order to spread the dose distribution over the anticipated tumor volume. The approach of delivering stable non-toxic isotopes to tumor, and then activating thes… more

Date: January 1, 1982

Creator: Fairchild, R.G.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Advances in Diagnostic Instrumentation

Developments in medical imaging in the last ten years are described. Techniques include fine focus x-ray tubes, computerized tomography, emission tomography, and ultrasonography. (ACR)

Date: January 1, 1980

Creator: Perez-Mendez, V.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Gamma densitometer for measuring Pu density in fuel tubes

A fuel-gamma-densitometer (FGD) has been developed to examine nondestructively the uniformity of plutonium in aluminum-clad fuel tubes at the Savannah River Plant (SRP). The monitoring technique is ..gamma..-ray spectroscopy with a lead-collimated Ge(Li) detector. Plutonium density is correlated with the measured intensity of the 208 keV ..gamma..-ray from /sup 237/U (7d) of the /sup 241/Pu (15y) decay chain. The FGD measures the plutonium density within 0.125- or 0.25-inch-diameter areas of th… more

Date: January 1, 1982

Creator: Winn, Willard G.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Scaling neutron absorbed dose distributions from one medium to another

Central axis depth dose (CADD) and off-axis absorbed dose ratio (OAR) measurements were made in water, muscle and whole skeletal bone TE-solutions, mineral oil and glycerin with a clinical neutron therapy beam. These measurements show that, for a given neutron beam quality and field size, there is a universal CADD distribution at infinity if the depth in the phantom is expressed in terms of appropriate scaling lengths. These are essentially the kerma-weighted neutron mean free paths in the medi… more

Date: November 1, 1982

Creator: Awschalom, M.; Rosenberg, I. & Ten Haken, R.K.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Harvard-MIT research program in short-lived radiopharmaceuticals

This report presents research on radiopharmaceuticals. The following topics are discussed: antibody labeling with positron-emitting radionuclides; antibody modification for radioimmune imaging; labeling antibodies; evaluation of technetium acetlyacetonates as potential cerebral blood flow agents; and studies in technetium chemistry. (CBS)

Date: January 1, 1991

Creator: Adelstein, S.J.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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D-T neutron generator development for cancer therapy. 1980 annual progress report

This report summarizes the work completed during the first year of a two-year grant by NCI/HEW to investigate the feasibility of developing a D-T neutron generator for use in cancer therapy. Experiments have continued on the Target Test Facility (TTF) developed during a previous grant to investigate high-temperature metal hydrides for use as target materials. The high voltage reliability of the TTF has been improved so that 200 kV, 200 mA operation is now routine. In recent target tests, the D-… more

Date: May 1, 1980

Creator: Bacon, F.M.; Walko, R.J.; Bickes, R.W. Jr.; Cowgill, D.F.; Riedel, A.A. & O'Hagan, J.B.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Neutron therapy facility at the Institute of High Energy Physics, Academia Sinica

The 10 MeV proton linac which was designed as preinjector for the Beijing 50 GeV Proton Synchrotron (BPS) was completed by the end of 1982. Because of the economic readjustment in the People's Republic of China the BPS project was cancelled. Then, the Institute of High Energy Physics decided to increase the energy of the linac from 10 MeV to 35.5 MeV. This increase will take place using the primary five megawatts RF system of the 10 MeV linac. This 35.5 MeV proton linac will be used for researc… more

Date: December 1, 1983

Creator: Zhu, Y.C.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Workshop on photon activation therapy: proceedings

This Workshop was held concurrently with an IAEA Research Coordination Meeting on Exploration of the Possibility of High-LET Radiation for Non-conventional Radiotherapy in Cancer. The Workshop on Photon Activation Therapy (PAT) was given as a special session on April 18, as it was thoght PAT might eventually be found to be attractive to developing countries, which is a major concern of the IAEA. An effort was made to bring together representatives of the various groups known to be actively work… more

Date: April 18, 1985

Creator: Fairchild, R.G. (ed.)

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Development and radiotherapeutic application of /sup 211/At-labeled radiopharmaceuticals. Progress report, March 1, 1981-February 28, 1982

This project is concerned with developing the potential of alpha-emitting radionuclides as agents for radiotherapy. Alpha-emitters seem ideally suited for his application because their high linear energy transfer and short range permit the deposition of considerable energy in a very small volume of tissue. Unlike the beta particles of /sup 131/I which have a range of about 1 to 2 mm in tissue, 5 to 7 MeV alpha particles would traverse only a few cell diameters. Among the available alpha-emitter… more

Date: January 1, 1981

Creator: Adelstein, S.J.; Zalutsky, M. & Bloomer, W.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Heavy-ion dosimetry

This lecture deals with some of the more important physical characteristics of relativistic heavy ions and their measurement, with beam delivery and beam monitoring, and with conventional radiation dosimetry as used in the operation of the BEVALAC biomedical facility for high energy heavy ions (Lyman and Howard, 1977; BEVALAC, 1977). Even so, many fundamental aspects of the interaction of relativistic heavy ions with matter, including important atomic physics and radiation chemical consideratio… more

Date: March 1, 1980

Creator: Schimmerling, W.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Overview of image reconstruction

Image reconstruction (or computerized tomography, etc.) is any process whereby a function, f, on R/sup n/ is estimated from empirical data pertaining to its integrals, ..integral..f(x) dx, for some collection of hyperplanes of dimension k < n. The paper begins with background information on how image reconstruction problems have arisen in practice, and describes some of the application areas of past or current interest; these include radioastronomy, optics, radiology and nuclear medicine, elect… more

Date: April 1, 1980

Creator: Marr, R.B.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Coupling of dextrans conjugated with boron to gamma globulin: a model for NCT

Our project is to meet more effectively the well known primary requirement for treatment with boron-10 neutron capture therapy (NCT): namely, the selective localization of a sufficient amount of boron in or on target cells. Monoclonal antibodies (MCA) to tumor-associated antigens are attractive targeting carriers for boron-10 in terms of the needed selective localization. However the densities of surface receptors on tumor cells have seemed deficient to achieve successful NCT. If one seeks the … more

Date: January 1, 1983

Creator: Elmore, J.J. Jr.; Borg, D.C.; Micca, P. & Gabel, D.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Photon-activation therapy

Photon Activation Therapy (PAT) is a technique in which radiation dose to tumor is enhanced via introduction of stable /sup 127/I in the form of iodinated deoxyuridine (IdUrd). Stimulation of cytotoxic effects from IdUrd is accomplished by activation with external (or implanted) radiation sources. Thus, accumulations of this nucleoside in actively competing cellpools do not preclude therapy in so far as such tissues can be excluded from the radiation field. Calculations show that 5% replacement… more

Date: January 1, 1982

Creator: Fairchild, R.G. & Bond, V.P.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Kinematics of Compton backscattering x-ray source for angiography

Calculations of X-Ray production rates, energy spread, and spectrum of Compton-backscattered photons from a Free Electron Laser on an electron beam in a low energy (136-MeV) compact (8.5-m circumference) storage ring indicate that an X-Ray intensity of 34.6 10{sup 7} X-Ray photons per 0.5-mm {times} 0.5-mm pixel for Coronary Angiography near the 33.169-keV iodine K-absorption edge can be achieved in a 4-msec pulse within a scattering cone of 1-mrad half angle. This intensity, at 10-m from the p… more

Date: May 1, 1992

Creator: Blumberg, L.N.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Radiation enhancement with /sup 127/I-deoxyuridine

A technique for radiation enhancement of photon radiotherapy is outlined. High LET radiations in the form of Auger electron distributions are generated by photoactivation of stable iodine incorporated as iodinated deoxyuridine (IdUrd). Of the several halogenated deoxyribonucleosides evaluated, IdUrd was found to be the only thymidine analog providing effective photoactivation. This mechanism is combined with radiation sensitization to produce an overall radiation enhancement. Calculations show … more

Date: June 1, 1982

Creator: Fairchild, R.G.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Radiobiology of pions at LAMPF

Recent radiobiology data for pion beams used in therapy are presented. The biological systems used were cultured cells suspended in gelatin and intestinal crypt assay. The importance of fast neutrons from pion stars in large treatment volumes is discussed. The data for compensating the depth dose distribution to produce uniform cell killing across the peak region are presented. The changes in biological effectiveness with peak width for pion beams (unlike heavy ions) are small because of fast n… more

Date: January 1, 1982

Creator: Raju, M.R. & Tokita, N.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Proton linac for hospital-based fast neutron therapy and radioisotope production

Recent developments in linac technology have led to the design of a hospital-based proton linac for fast neutron therapy. The 180 microamp average current allows beam to be diverted for radioisotope production during treatments while maintaining an acceptable dose rate. During dedicated operation, dose rates greater than 280 neutron rads per minute are achievable at depth, DMAX = 1.6 cm with source to axis distance, SAD = 190 cm. Maximum machine energy is 70 MeV and several intermediate energie… more

Date: September 1, 1989

Creator: Lennox, A. J.; Hendrickson, F. R.; Swenson, D. A.; Winje, R. A.; Young, D. E. (Fermi National Accelerator Lab., Batavia, IL (USA); Rush Univ., Chicago, IL (USA) et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Dosimetric implications of new compounds for neutron capture therapy (NCT)

Systemic application of radiolabeled or cytotoxic agents should allow targeting of primary and metastatic neoplasms on a cellular level. In fact, drug uptake in non-target cell pools often exceeds toxic levels before sufficient amounts are delivered to tumor. In addition, at the large concentration of molecules necessary for therapy, effects of saturation are often found. Application of NCT can circumvent problems associated with high uptake in competing non-target cell pools, as the /sup 10/B(… more

Date: January 1, 1982

Creator: Fairchild, R.G.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Heavy-ion radiography and heavy-ion computed tomography

Heavy-ion projection and CT radiography is being developed into a safe, low-dose, noninvasive radiological procedure that can quantitate and image small density differences in human tissues. The applications to heavy-ion mammography and heavy-ion CT imaging of the brain in clinical patients suggest their potential value in cancer diagnosis.

Date: February 1, 1982

Creator: Fabrikant, J. I.; Holley, W. R.; McFarland, E. W. & Tobias, C. A.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Improved radioimmunotherapy of hematologic malignancies

This research project proposes to develop novel new approaches of improving the radioimmunodetection and radioimmunotherapy of malignancies by augmenting retention of radioimmunoconjugates by tumor cells. The approaches shown to be effective in these laboratory experiments will subsequently be incorporated into out ongoing clinical trials in patients. Specific project objectives include: to study the rates of endocytosis, intracellular routing, and metabolic degradation of radiolabeled monoclon… more

Date: March 24, 1992

Creator: Press, O.W.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Pulsed system for obtaining microdosimetric data with high intensity beams

The use of heavy particle accelerators for radiation therapy requires high intensity beams in order to produce useful dose rates. The 800-MeV proton beam at LAMPF passes through different production targets to generate secondary pion beams. Conventional microdosimetric techniques are not applicable under these conditions because exceedingly high count rates result in detector damage, gas breakdown, and saturation effects in the electronics. We describe a new microdosimetric system developed at … more

Date: January 1, 1977

Creator: Zaider, M.; Dicello, J.F. & Hiebert, R.D.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Pion production cross sections and associated parameters

Negative pions have been used for radiotherapy at the meson factories LAMPF (USA), SIN (Switzerland), and TRIUMF (Canada) and have been planned for use at new meson facilities under construction (USSR) and at proposed dedicated medical facilities. Providing therapeutically useful dose rates of pions requires a knowledge of the pion production cross sections as a function of primary proton energy (500 to 1000 MeV), pion energy (less than or equal to100 MeV), production angle, and target material… more

Date: January 1, 1985

Creator: Bradbury, J.N.

Item Type: Article

Partner: UNT Libraries Government Documents Department