[en] The prospects of an energy consensus between the p[arties have faded away. The Social Democrats and Christian Democrats are jeopardizing the possible compromise between coal and nuclear energy. Now there are efforts to concoct a new energy tax. The economy must prepare to cope with higher costs for nuclear energy and coal. (HP)

[en] This article examines the impact on the independent energy companies of the Public Utilities Holding Company Act (PUHCA) in development of opportunities in the international private power market. This market is expected to expand by an additional 43,400 megawatts of new capacity in developing and developed countries by the year 2000. The topics include holding company regulation, exemptions from regulation, and the potential for reform of the PUHCA

[en] Purpose: To aid in design of conformal radiation therapy treatment plans involving many conformally shaped fields, this work investigates the use of two methodologies to enhance the ease of interactive treatment planning: high-level beam constructs and beam's-eye view volumetric mapping. Methods and Materials: High-performance computer graphics running on various workstations using a graphical visualization system (AVS) have been used in this work. Software specific to this application has been written in standard FORTRAN and C languages. A new methodology is introduced by defining radiation therapy 'fields' to be composed of multiple beam 'segments'. Fields can then be defined as higher-level entities such as arcs, cones, and other shapes. A 'segmental cone' field, for example, is defined by a symmetry axis and a cone angle, and can be used to rapidly place a series of beam segments that converge at the target volume, while reducing the degree of overlap elsewhere. A new beam's-eye view (BEV) volumetric mapping technique is presented to aid in selecting the placement of conformal radiation fields. With this technique, the relative average dose within an organ of interest is calculated for a sampling of isocentric, conformally shaped beams and displayed either as a ''globe,'' which can be combined with the display of anatomical surfaces, or as a two-dimensionally mapped projection. The dose maps from multiple organs can be generated, stacked, or composited with relative weightings to aid in the placement of fields that minimize overlap with critical structures. Results: The use of these new methodologies is demonstrated for prostate and lung treatment sites and compared to conventional planning techniques. Discussion: The use of many beams for conformal treatment delivery is difficult with current interactive planning. The use of high-level beam constructs provides a means to quickly specify, place, and configure multiple beam arrangements. The BEV volumetrics aids in the placing of fields, which minimize involvement with critical normal tissues. Conclusions: Early experience with the new methodologies suggest that the new methods help to enhance (or at least speed up) the ability of a treatment planner to create optimal radiation treatment field arrangements

[en] Runoff transcripts were generated on viral transcriptional complexes cleaved with restriction enzymes and incubated in vitro with [alpha-³²P]UTP under pulse-chase conditions. As viral transcriptional complexes in vitro elongated the nascent RNA preinitiated in vivo, size analysis by gel electrophoresis of the runoff transcripts allowed identification of the in vivo initiation sites. Moreover, scanning the intensities of the runoff bands as they appeared in the autoradiogram of the gel allowed determination of the relative use of these sites. A model system in which the initiation sites of simian virus 40 late RNA were identified and their relative use determined is presented

[en] Lipids labelled with deuterium or carbon-14 have been investigated by field desorption mass spectrometry for determination of their degree of labelling. This application is demonstrated for free fatty acids, cholesterol, cholesteryl esters, triglycerides, and L-α-phosphatidylcholines. Comparison of the molecular ion groups of the non-labelled and of the labelled compounds enables a fast and reliable determination of the degree of labelling. For multiply labelled compounds the label distribution is also obtained from the molecular ion group. In addition, for cholesteryl esters and for phosphatidylcholines structurally significant fragment ions provide information about the position of the label. Several hundred nanograms of the compound are typically required for a single analysis with a relative standard error of 0.5-2% in the value calculated for atom% hydrogen-2 or for the specific carbon-14 activity. (orig.)

[en] Deformable image registration, contour propagation and dose mapping have become common, possibly essential tools for modern image-guided radiation therapy. Historically, these tools have been largely developed at academic medical centers and used in a rather limited and well controlled fashion. Today these tools are now available to the radiotherapy community at large, both as stand-alone applications and as integrated components of both treatment planning and treatment delivery systems. Unfortunately, the details of how these tools work and their limitations are not generally documented or described by the vendors that provide them. Although “it looks right”, determining that unphysical deformations may have occurred is crucial. Because of this, understanding how and when to use, and not use these tools to support everyday clinical decisions is far from straight forward. The goal of this session will be to present both the theory (basic and advanced) and practical clinical use of deformable image registration, contour propagation and dose mapping. To the extent possible, the “secret sauce” that different vendor use to produce reasonable/acceptable results will be described. A detailed explanation of the possible sources of errors and actual examples of these will be presented. Knowing the underlying principles of the process and understanding the confounding factors will help the practicing medical physicist be better able to make decisions (about making decisions) using these tools available. Learning Objectives: Understand the basic (101) and advanced (201) principles of deformable image registration, contour propagation and dose mapping data mapping. Understand the sources and impact of errors in registration and data mapping and the methods for evaluating the performance of these tools. Understand the clinical use and value of these tools, especially when used as a “black box”

[en] During the past year three new elements have been introduced into the beam line at the Bevatron to improve patient treatment. These are the wobbler magnets, the bar-ridged filters, and the binary absorber. The wobbler consists of a pair of orthogonal dipole magnets that sweep the beam in concentric circles up to 30 cm in diameter. This device replaces the lead scattering-foil system for spreading the beam laterally. This change allows the reduction of the beam energy from 670 MeV/amu to 585 MeV/amu while maintaining the same depth of penetration in the patient. The binary absorber is a set of copper and aluminium plates of binary increments in thickness. Like the variable thickness water column, which it replaces, the binary range absorber sets the residual range of the particles as they enter the final patient compensating filtering. 6 refs., 3 figs., 1 tab

[en] A case of fibromuscular dysplasia of the brachial artery in a 44-year-old woman is presented with simultaneous manifestation in the renal arteries and relief of symptoms after oral corticoid therapy. (orig.)

[en] Wolfe has suggested that there is a correlation between the pattern of the breast parenchyma and the risk of a carcinoma. This has been confirmed by some authors and denied by others. Our investigations of 905 cases could not confirm Wolfe's thesis and suggested his results were due to selection of cases. Our findings confirm the opinion expressed several times in the literature that the women with a breast parenchymal pattern P₂ and DY regarded by Wolfe as high risk patients are not distinguished by an increased risk, but by the fact that existing carcinomas tend to be missed by radiologists. (orig.)

[en] Precision radiation therapy requires accurate delineation of the tumour and normal tissues in the planning phase and accurate localisation of these structures during the delivery phase. The definition of the gross tumour volume (GTV) and specification of appropriate margins around the GTV dictate the maximum radiation doses that may be safely delivered. Ongoing developments in multimodality and 4D imaging technologies are providing opportunities to improve tumour localisation and patient modelling for treatment planning and to reduce setup variations and PTV margin size for treatment delivery. Proper use of these technologies can provide greater sparing of dose to normal tissues and permit safer escalation of tumour doses. Imaging techniques are also being developed to help predict response to treatment during therapy when interventions and adaptations are still possible. Optimal use of these technologies requires tools to spatially register multimodality and time series image data, and once registered to transfer and integrate anatomical, functional and dosimetric information from the different imaging studies. This review provides an overview of the mechanics of image registration and fusion and examples of their use. (authors)