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An estimated 10 % of breast cancer cases exhibit a higher familial incidence, and functional mutations in BRCA (breast cancer-gene) 1 or 2 are responsible for the development of malignant tumors in approximately half of these cases. Women with a germline mutation in either of the two genes have a lifetime risk of up to 85 % to develop breast cancer, and of up to 60 % risk to develop ovarian cancer. This clinical practice guideline defines the individual and familial tumor constellations that represent an indication for BRCA germline testing. It also describes the therapeutic options (early detection programme vs prophylactic surgery) that arise from the result of a BRCA mutational analysis. This guideline further includes recommendations regarding the use of multigene panels and therapeutic aspects that arise from the selective use of poly ADP ribose polymerase (PARP) inhibitors in patients with known BRCA1 or 2 mutations. It replaces the previous version of the 'Clinical Practice Guideline for the Prevention and Early Detection of Breast- and Ovarian Cancer in women from HBOC (hereditary breast and ovarian cancer) families' which was published in 2012. [ABSTRACT FROM AUTHOR]

The objective of this study was to describe the experience of genetic testing in Austrian women with a BRCA1 or BRCA2 mutation in terms of preventive measures taken and incident cancers diagnosed. We collected clinical information on 246 Austrian women with a BRCA1 or BRCA2 mutation tested between 1995 and 2012 and followed 182 of them for an average of 6.5 years. Of the 90 women who were cancer-free at baseline, 21.4% underwent preventive bilateral mastectomy, 46.1% had preventive bilateral salpingo-oophorectomy, and 1 took tamoxifen; 58.8% of the at-risk women underwent at least one screening breast magnetic resonance imaging ( MRI). Of the 85 women with breast cancer, 69.4% had a unilateral mastectomy or lumpectomy and 30.6% had a contralateral mastectomy. In the follow-up period, 14 new invasive breast cancers (6 first primary and 8 contralateral), 1 ductal carcinoma in situ case, 2 incident ovarian cancer cases, and 1 peritoneal cancer were diagnosed. In Austria, the majority of healthy women with a BRCA1 or BRCA2 mutation opt for preventive oophorectomy and MRI screening to manage their breast cancer risk; few have preventive mastectomy or take tamoxifen. [ABSTRACT FROM AUTHOR]

This work studies the impact of estimating soil wave number in Underground Focused SAR imaging for tunnel detection applications. It is demonstrated that neglecting wave refraction at the ground surface results in poor underground imaging; however, by considering refraction with inexact, yet sufficiently high, estimates of soil dielectric constant, clear target images can be produced. In addition, using a wrong wave number for the soil incorrectly predicts the tunnel's depth, but gives positive identification of its transverse extent. [ABSTRACT FROM AUTHOR]

This paper deals with the problem of detecting potential suicide bombers wearing concealed metallic and dielectric objects. The data produced by Millimeter-Wave-Radar system, working on a Multiple Frequency-Multiple Transmitters and Multiple Receivers configuration (MF-MTMR), is synthetically generated by an electromagnetic code based on Finite Differences Frequency Domain (FDFD) method. The numerical code provides the scattered field produced by the subject under test, which is later processed by using a multiple bistatic Synthetic Aperture Radar (SAR) algorithm. The blurring effect produced by the Point Spread Function (PSF) in the SAR image is removed by applying a regularized deconvolution algorithm that uses only magnitude information (no phase). Finally, the SAR algorithm and the deconvolution procedure are tested on a person wearing metallic and dielectric objects. The SAR response of dielectric rods is quite different from the metallic pipes. Our algorithm not only distinguishes between cases but also is capable of estimating the dielectric constant of the rods. Each constitutive parameter directly maps to the dielectric constant of explosive compounds, such as TNT or RDX, making feasible the detection of potential suicide bombers. [ABSTRACT FROM AUTHOR]

The semianalytic mode matching (SAMM) algorithm is a quick and efficient computational method that models wave scattering from multiple objects in half-spaces. This algorithm re lies heavily on appropriate choices of coordinate scattering centers (CSCs) for various modal expansions. Here, SAMM is used to simulate scattering from irregularly shaped 2-D lossy objects embedded in realistic half-space media with rough ground surfaces. Because the CSC locations for complex scatterers are much more dependent on object or interface geometry than frequency and are independent of the dielectric contrast between scatterer and back ground, it is worthwhile to carefully analyze particular scattering object shapes and store the optimal CSC locations for future use. In addition, scattering from multiple targets buried beneath rough ground surfaces can be constructed from simpler simulations of the individual targets taken separately, where combining these simpler simulations correctly can increase robustness in large SAMM simulations. Excellent results are found by comparing 2-D SAMM with 2-D finite-difference frequency domain for multiple scattering objects on the order of a fraction to several wavelengths in size located within rough half-space dielectric backgrounds. [ABSTRACT FROM PUBLISHER]

This work extends the mathematical formulation of the iterative-field-matrix method for observed data from the near-field region of a Perfect Electric Conductor. The method is used as a diagnosis tool for reflector antennas, to determine the positions and extent of distortions from their idealized shapes. The new formulation is tested on a reflector antenna with several significant bumps, and excellent results are achieved. This work also presents an example where the Method of Moments is used to generate the synthetic data and the inversion is performed using Physical Optics. Such a configuration ensures that the forward model is unbiased with respect to the inversion model, demonstrating that the new formulation is also robust for these realistic scenarios. [ABSTRACT FROM PUBLISHER]

An approximation is presented for the calculation of the equivalent currents based on the oblique incidence of a plane wave on the interface between free space and lossy dielectric media. The Snell reflection coefficients establish the relation between incident and reflected waves, then, the boundary conditions establish the equivalent electric/magnetic currents in the free space region using the total magnetic/electric fields. The interface is discretized into planar triangular facets, on which currents are assumed to have constant amplitude and linear phase variation in order to analytically calculate the scattered fields. Our modified equivalent current approximation (MECA) reduces to the well-studied physical optics (PO) formulation in case of PEC surfaces. Simulations to validate the formulation are performed over electrically large canonical geometries – a lossy dielectric sphere, a rough plate and a right dihedral – to compare the calculated Radar cross section (RCS). Good agreement between MECA and analytical/method of moments (MoM) results is demonstrated. [ABSTRACT FROM PUBLISHER]

The common condition of atrial fibrillation is often treated by cutting diseased cardiac tissue to disrupt abnormal electrical conduction pathways. Heating abnormal tissue with electromagnetic power provides a minimally invasive surgical alternative to treat these cardiac arrhythmias. Radio frequency ablation has become the method of choice of many physicians. Recently, microwave power has also been shown to have great therapeutic benefit in medical treatment requiring precise heating of biological tissue. Since microwave power tends to be deposited throughout the volume of biological media, microwave heating offers advantages over other heating modalities that tend to heat primarily the contacting surface. It is also possible to heat a deeper volume of tissue with more precise control using microwaves than with purely thermal conduction or RF electrode heating. Microwave Cardiac Ablation (MCA) is used to treat heart tissue that allows abnormal electrical conduction by heating it to the point of inactivation. Microwave antennas that fit within catheter systems can be positioned close to diseased tissue. Specialized antenna designs that unfurl from the catheter within the heart can then radiate specifically shaped fields, which overcome problems such as excessive surface heating at the contact point. The state of the art in MCA is reviewed in this paper and a novel catheter-based unfurling wide aperture antenna is described. This antenna consists of the centre conductor of a coaxial line, shaped into a spiral and insulated from blood and tissue by a non-conductive fluid filled balloon. Initially stretched straight inside a catheter for transluminal guiding, once in place at the cardiac target, the coiled spiral antenna is advanced into the inflated balloon. Power is applied in the range of 50-150 W at the reserved industrial, scientific and medical (ISM) frequency of 915 MHz for 30-90 s to create an irreversible lesion. The antenna is then retracted back into the catheter for removal. Simulated and experimental measurements on phantoms, in vitro animal organ tissue and living animals have shown that these microwave applicators deliver the intended therapeutic lesions that are both wider and deeper than those generated by RF ablation or other recently reported microwave applicators. [ABSTRACT FROM AUTHOR]

Two applications of microwave internal biological heating are discussed. Both microwave assisted balloon angioplasty (MABA) and microwave cardiac ablation (MCA) consist of an antenna applicator fed by means of coaxial cable, which passes through a catheter. The antenna designs take advantage of polarization and phase effects of microwaves to create specific power deposition patterns. MABA with a helix and mode filter balloon uses the large differences in the dielectric characteristics of high water content (HWC) and low water content (LWC) tissue to preferentially heat and weld plaque while sparing healthy artery walls. Wide aperture MCA uses an unfurlable spiral antenna within a balloon to generate a deep large ablation volume in diseased cardiac tissue. Theoretical studies have been validated with a variety of in-vitro and in-vivo experiments. There is less of a potential for tissue-surface charring with microwaves than with RF ablation. Live animal studies indicate that MCA is well tolerated by animals [ABSTRACT FROM PUBLISHER]

A rigorous electromagnetic model has been used to analyze the scattering from two dielectric shallow objects buried under the two-dimensional (2-D) random rough ground (3-D scattering problem) as a means of predicting false alarms. The method of moments (MoM) accelerated by the steepest descent fast multipole method (SDFMM) is used to compute the equivalent electric and magnetic surface currents on all scatterers (i.e., the rough ground and the two buried objects). The roughness parameters influence the scattering interference mechanism of the two objects, however, a large separation distance (e.g., several correlation lengths) showed stronger effect for small ground roughness. [ABSTRACT FROM PUBLISHER]

We present the parallel, MPI-based implementation of the SDFMM computer code using a thirty-two node Intel Pentium-based Beowulf cluster. The SDFMM is a fast algorithm that is a hybridization of the method of moments (MoMs), the fast multipole method (FMM), and the steepest descent integration path (SDP), which is used to solve large-scale linear systems of equations produced in electromagnetic scattering problems. An overall speedup of 7.2 has been achieved on the 32-processor Beowulf cluster and a significant reduced runtime is achieved on the 4-processor 667 MHz Alpha workstation [ABSTRACT FROM PUBLISHER]