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Dose inhomogeneities at various levels of biological organization

Dose inhomogeneities in both tumor and normal tissue, inherent to the application of boron neutron capture therapy (BNCT), can be the result not only of ununiform distribution of /sup 10/B at various levels of biological organization, but also of the distribution of the thermal neutrons and of the energy depositions from more energetic neutrons and other radiations comprising the externally-applied beams. The severity of the problems resulting from such inhomogeneities, and approaches to evalua… more

Date: January 1, 1988

Creator: Bond, V. P.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Potential for heavy particle radiation therapy

Radiation therapy remains one of the major forms of cancer treatment. When x rays are used in radiotherapy, there are large variations in radiation sensitivity among tumors because of the possible differences in the presence of hypoxic but viable tumor cells, differences in reoxygenation during treatment, differences in distribution of the tumor cells in their cell cycle, and differences in repair of sublethal damage. When high-LET particles are used, depending upon the LET distribution, these … more

Date: March 1, 1977

Creator: Raju, M. R. & Phillips, T. L.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Mechanisms of calcium transport in small intestine. Overall review of the contract, September 1, 1972--March 1, 1976

Progress is reported in the following areas of research: role of high molecular weight protein in calcium transport in vitamin D deficient chicks; subcellular localization of 1,25-(OH)/sub 2/D/sub 3/; receptor proteins for 1,25-(OH)/sub 2/D/sub 3/; effects of high calcium diet, strontium diet, EHDP, and parathyroidectomy on intestinal calcium transport in chicks; effects of analogs of 1,25-(OH)/sub 2/D/sub 3/ on intestinal calcium transport; discrimination by chicks against vitamin D/sub 2/ com… more

Date: January 1, 1976

Creator: DeLuca, H. F.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Development and use of a fifteen year-old equivalent mathematical phantom for internal dose calculations. [Radiation dose distributions from /sup 99m/Tc-labeled compounds]

The existence of a phantom based on anatomical data for the average fifteen-year-old provides for a proficient means of obtaining estimates of absorbed dose for children of that age. Dimensions representative of an average fifteen-year-old human, obtained from various biological and medical research, were transformed into a mathematical construct of idealized shapes of the exterior, skeletal system, and internal organs of a human. The idealization for an average adult presently in use by the In… more

Date: June 1, 1976

Creator: Jones, R. M.; Poston, J. W.; Hwang, J. L.; Jones, T. D. & Warner, G. G.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Application of longitudinal magnification effect to magnification stereoscopic angiography. A new method of cerebral angiography

A new method of stereoscopic cerebral angiography was developed which employs 2X radiographic magnification. In order to obtain the same depth perception in the object as with conventional contact stereoscopic angiography, one can make the x-ray exposures at two focal spot positions which are separated by only 1 inch, whereas the contact technique requires a separation of 4 inches. The smaller distance is possible because, with 2X magnification, the transverse detail in the object is magnified … more

Date: January 1, 1976

Creator: Doi, K.; Rossmann, K. & Duda, E. E.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Automatic detection of alternations in pulmonary venous pressure

Image processing and pattern recognition techniques are useful in radiology to aid in the decision making process involving disease patterns in radiographs. The long range goal of this study is to develop a completely automated computer controlled optical system for early detection and classification of prepulmonary edema. This is achieved from chest x-rays by observing and measuring certain patterns of lung vascularity which enable us to characterize the presence and severity of the disease. T… more

Date: January 1, 1977

Creator: Strand, T. C.; Turner, A. F.; Meyers, H. I. & Kruger, R. P.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Clinical high-purity germanium gamma-camera

The need in clinical nuclear medicine for imaging devices with high spatial resolution has been discussed at length for many years. More recently, specialists in cardiology and neurology have restated this need for greater resolution in order to effect earlier or more accurate diagnoses of brain tumors, cerebral and myocardial ischemia and infarcts and septum defects, among others. Our approach to filling this need is to ultimately develop a 3072-element, high-purity germanium camera with a 2-m… more

Date: October 4, 1976

Creator: Ewins, J. H.; Armantrout, G. A.; Camp, D. C.; Kaufman, L.; Hattner, R. S.; Price, D. C. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Technical assessment of the Loma Linda University proton therapy accelerator

In April 1986, officials of Loma Linda University requested that Fermilab design and construct a 250 MeV proton synchrotron for radiotherapy, to be located at the Loma Linda University Medical Center. In June 1986 the project, having received all necessary approvals, commenced. In order to meet a desirable schedule providing for operation in early 1990, it was decided to erect such parts of the accelerator as were complete at Fermilab and conduct a precommissioning activity prior to the complet… more

Date: October 1, 1989

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Determination of x-ray spectra incident on and transmitted through whole excised breast for improved mammographic exposing technique

Measurements were made of x-ray spectra incident on and transmitted through whole excised fresh breast tissue. The spectra and corresponding radiographs show that hardening of the x-ray beam from a molybdenum anode x-ray tube by a 0.5 mm Al filter instead of the conventional 0.03 mm Mo filter allows shorter exposure times and reduces patient radiation exposure. With the Al filter, acceptable image contrast is preserved in mammography of thick or dense breasts.

Date: January 1, 1976

Creator: Haus, A. G.; Metz, C. E.; Doi, K. & Bernstein, J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Present and future sources of protons and heavy ions. [Medical facilities]

A brief outline of existing medical heavy-ion facilities is given. The beam specifications for future dedicated medical ion accelerators are discussed. Machines capable of delivering dose rates of approximately 1 krad/min in volumes of a few liters are shown to represent existing technology. A cost and performance analysis shows the synchrotrons to be the most economical source for the heavier ions while conventional cyclotrons seem optimal for an exclusive proton facility. It is seen that the … more

Date: September 13, 1976

Creator: Grunder, H. A. & Leemann, C. W.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Fermilab neutron radiotherapy facility

A facility for testing the effectiveness of high energy neutrons for the treatment of malignant tumors has been constructed at the Fermi National Accelerator Laboratory. The first neutrons were produced by the bombardment of 66-MeV protons on a beryllium target in July, 1975. After physically characterizing the neutron beam and performing preliminary radiobiological experiments, patient treatment started in September, 1976. At the time of this writing, 52 patients had been treated. A descriptio… more

Date: January 1, 1977

Creator: Awschalom, M.; Lee, G. M.; Palmer, M. L. & Young, D. E.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Radionuclide imaging with coded apertures and three-dimensional image reconstruction from focal-plane tomography

Two techniques for radionuclide imaging and reconstruction have been studied;; both are used for improvement of depth resolution. The first technique is called coded aperture imaging, which is a technique of tomographic imaging. The second technique is a special 3-D image reconstruction method which is introduced as an improvement to the so called focal-plane tomography. (auth)

Date: May 1, 1976

Creator: Chang, L. T.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Dosimetry of beams for negative pi-meson radiation therapy

Several new facilities have been built in the last few years which can produce high intensity beams of pions. As a result, a significant amount of new data related to pion dosimetry is available. Results of beam composition, beam shaping, and collimation are given along with depth dose curves and isodose contours. Experimental data which describe the radiation quality of pion beams and the change in radiation quality with position are presented. Experimental data determining the fraction of the… more

Date: January 1, 1976

Creator: Dicello, J. F.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Why is a high accuracy needed in dosimetry. [Radiotherapy]

Dose and exposure intercomparisons on a national or international basis have become an important component of quality assurance in the practice of good radiotherapy. A high degree of accuracy of ..gamma.. and x radiation dosimetry is essential in our international society, where medical information is so readily exchanged and used. The value of accurate dosimetry lies mainly in the avoidance of complications in normal tissue and an optimal degree of tumor control.

Date: January 1, 1976

Creator: Lanzl, L. H.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Californium-252 radiotherapy sources for interstitial afterloading

Californium-252 neutron sources for interstitial afterloading were developed to investigate the value of this radionuclide in cancer therapy. Californium-252 seed assemblies contain essentially point sources of /sup 252/Cf permanently sealed on 1-cm centers within a flexible plastic tube. The seed assemblies are fabricated with remotely operated, specially designed machines. The fabrication process involves the production of a Pt-10 percent Ir-clad wire with a /sup 252/Cf/sub 2/O/sub 3/-Pd cerm… more

Date: January 1, 1976

Creator: Permar, P. H. & Walker, V. W.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Clinical-radiological evaluation of sequelae of stereotactic radiosurgery for intracranial arteriovenous malformations

Stereotactic heavy-charged-particle Bragg peak radiosurgery has been used to treat 322 patients with surgically-inaccessible intracranial vascular malformations. (The clinical results of this method for the treatment of angiographically demonstrable arteriovenous malformations (AVMs) and angiographically occult vascular malformations (AOVMs) of the brain are described in separate reports of this symposium). The great majority of patients have had an uneventful post-treatment course with satisfa… more

Date: December 1, 1989

Creator: Levy, R. P.; Fabrikant, J. I.; Frankel, K. A.; Phillips, M. H.; Steinberg, G. K.; Marks, M. P. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Low-energy linac structure for PIGMI. [Pion generator for medical irradiations (PIGMI)]

The higher radio frequency (450 MHz) and lower injection energy (250 keV) of the PIGMI (Pion Generator for Medical Irradiations) linac design seriously compound the problem of beam containment in the first few meters of the structure. The conventional quadrupole-focused, drift-tube linac represents the best solution for beam energies above 8 MeV, but because of the small space available for quadrupoles in the PIGMI designs, cannot provide the required focusing at lower energies. A satisfactory … more

Date: January 1, 1977

Creator: Swenson, D. A. & Stovall, J. E.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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In-phantom spectrometry of medical diagnostic x rays

A program of measurements was made to determine the spectral fluence distributions at locations of significance in a heterogeneous, hominoid phantom exposed to x rays in a manner simulating medical diagnostic radiology. The measurements were made with a specially constructed NaI(Tl) scintillation detector. The detector had a spherically shaped active volume 0.6 cm in diameter. The resolution of this detector was five times worse than that of a more conventional NaI(Tl) spectrometer. Resolution … more

Date: October 1, 1977

Creator: Stansbury, P. S.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Computer system for radiation therapy with negative pions

Since 1974 Cancer Therapy Research has been conducted at the Clinton P. Anderson Meson Physics Facility, Los Alamos Scientific Laboratory, Los Alamos, New Mexico using negative pi-mesons. Through 1977 all treatments will have been static scan treatments, during which a DEC PDP-11/45 computer was used to monitor, record and verify channel and treatment parameters. This computer system has an RSX-11D operating system, and communicates with hardware via CAMAC. Beginning in 1978, dynamic scan treat… more

Date: January 1, 1977

Creator: Helland, J. A. & Kittell, R. S.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Clinical results of stereotactic hellium-ion radiosurgery of the pituitary gland at Lawrence Berkeley Laboratory

The first therapeutic clinical trial using accelerated heavy-charged particles in humans was performed at Lawrence Berkeley Laboratory (LBL) for the treatment of various endocrine and metabolic disorders of the pituitary gland, and as suppressive therapy for adenohypophyseal hormone-responsive carcinomas and diabetic retinopathy. In acromegaly, Cushing's disease, Nelson's syndrome and prolactin-secreting tumors, the therapeutic goal in the 433 patients treated has been to destroy or inhibit the… more

Date: December 1, 1989

Creator: Levy, R. P.; Fabrikant, Jacob I.; Lyman, J. T.; Frankel, K. A.; Phillips, M. H.; Lawrence, J. H. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Bevalac Operations, 1991

This report discusses the following aspects of the Bevalac: Accelerator Technology and Operations Summary; Support for Space Exploration; Nuclear Science Research; and Biomedical Research.

Date: March 1, 1992

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Effects of target size on the comparison of photon and charged particle dose distributions

The work presented here is part of an ongoing project to quantify and evaluate the differences in the use of different radiation types and irradiation geometries in radiosurgery. We are examining dose distributions for photons using the Gamma Knife'' and the linear accelerator arc methods, as well as different species of charged particles from protons to neon ions. A number of different factors need to be studied to accurately compare the different modalities such as target size, shape and loca… more

Date: December 1, 1989

Creator: Phillips, Mark H.; Frankel, Kenneth A.; Tjoa, Tom; Lyman, John T.; Fabrikant, Jacob I. & Levy, Richard P.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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LASL ion linear accelerator program. [Applications in neutron therapy]

The LASL ion linear accelerator program PIGMI and the application of the technology developed in this program to neutron therapy equipment is described.

Date: January 1, 1976

Creator: Knapp, E. A. & Swenson, D. A.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Fan beam and parallel beam projection and back-projection operators

Expressions for the fan beam and parallel beam projection and back-projection operators are given along with an evaluation of the point source response for the back-projection operators. The back-projection operator for the fan beam geometry requires the superposition of projection data measured over 360/sup 0/. Both the fan beam and parallel beam geometries have back-projection operators with point source responses which are proportional to 1/mod (r-r/sub 0/), and thus two-dimensional Fourier … more

Date: January 1, 1977

Creator: Gullberg, G. T.

Item Type: Report

Partner: UNT Libraries Government Documents Department