BackgroundAssessment of tumor size changes is crucial in clinical trials and patient care. We compared imatinib-induced volume changes of liver metastases (LM) from gastro-intestinal stromal tumors (GIST) to RECIST and Choi criteria and their association with overall survival (OS).MethodsLM from 84 GIST patients (training and validation set) were evaluated using manual and semi-automated Computed Tomography measurements at baseline, after 3, 6 and 12 months of imatinib. The ability of uni-dimensional (1D) and three-dimensional (3D) measurements to detect size changes (increase/decrease) ≥20% was evaluated. Volumetric response cut-offs were derived from minimally relevant changes (+20/−30%) by RECIST, considering lesions as spherical or ellipsoidal.Results3D measurements detected size changes ≥20% more frequently than 1D at every time-point (P≤0.008). 3D and Choi criteria registered more responses than RECIST at 3 and 6 months for 3D-spheres (P≤0.03) and at all time-points for 3D-ellipsoids and Choi criteria (P<0.001). Progressive disease by 3D criteria seems to better correlate to OS at late time-points than other criteria.ConclusionVolume criteria (especially ellipsoids) classify a higher number of patients as imatinib-responders than RECIST. Volume discriminates size changes better than diameter in GIST and constitutes a feasible and robust method to evaluate response and predict patient benefit.

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An accurate description of typical finite-array behavior such as edge effects and array resonances is essential in the design of various types of antennas. The analysis approach proposed in this paper is essentially based on the concept of eigencurrents and is capable of describing finite-array behavior. In the approach numerical simulation is carried out, first, by computing element eigencurrents from chosen expansion functions and, second, by expanding a limited set of array eigencurrents in terms of element eigencurrents that contribute to the mutual coupling in the array. Both types of eigencurrents are eigenfunctions of an impedance operator that relates the current to the excitation field. Highlighting both mathematical and physical features we describe the basic concepts of the approach, in particular the relation between eigenvalues and mutual coupling. We illustrate these features for uniform linear arrays of loops and dipoles, and demonstrate that the approach provides significant improvements in terms of computation time and memory use.Index Terms-Antenna arrays, dipole arrays, eigenvalues and eigenfunctions, integrodifferential equations, loop antenna arrays, method of moments (MoM), mutual coupling, resonance.

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Abstract-Post-wall waveguides can fulfill the requirements for low-loss transmission lines and components in the interconnection between antenna and front-end electronics. In this paper we present a model based on an element-by-element method for simulating wave propagation in metallic and dielectric post-wall waveguides. We demonstrate that both types of waveguides support wave propagation and we show that undesired resonances can limit the range of operation.

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