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The verification of thermal models for use in hyperthermia treatment planning is essential. We investigated the heat transfer between a single vessel and the surrounding vascularised tissue, comparing the conventional bioheat transfer theory and the recently developed keff model using analytical and numerical methods. A plastic tube inserted into the tissue(More)
During hyperthermia the presence of a large vessel entering the heated volume and carrying blood at the systemic temperature can be an important source of temperature non-uniformity and possible underdosage. The minimal tumour temperature near a large vessel is determined by the vessel wall temperature: a number of factors influencing the vessel wall(More)
We have developed a thermal model in which blood vessels are described as geometrical objects, 3D curves with associated diameters. Here the behaviour of the model is examined for low resolutions compared with the vessel diameter and for strongly curved vessels. The tests include a single straight vessel and vessels describing the path of a helix embedded(More)
Scanned focused ultrasound (SFUS) is unique amongst noninvasive methods of inducing hyperthermia in that the absorbed power (SAR) distribution may be controlled at a scale of 0.5 cm or better. This high degree of spatial control of SAR implies that differences in local tissue cooling due to heterogeneity in perfusion, variations in the density of discrete(More)
Temperature distributions resulting from hyperthermia treatments on isolated perfused bovine tongues were compared with simulations by a treatment planning system. The aim was to test whether the discrete vessel model used for the treatment planning is able to predict correct generic temperature distributions. Tongues were heated with the multielectrode(More)
We have developed a thermal model, for use in hyperthermia treatment planning, in which blood vessels are described as geometrical objects; 3D curves with associated diameters. For the calculation of the heat exchange with the tissue an analytic result is used. To arrive at this result some assumptions were made. One of these assumptions is a cylindrically(More)
PURPOSE The graphical processing unit (GPU) on modern graphics cards offers the possibility of accelerating arithmetically intensive tasks. By splitting the work into a large number of independent jobs, order-of-magnitude speedups are reported. In this article, the possible speedup of PLATO's ray tracing algorithm for dose calculations using a GPU is(More)
Hyperthermia treatment planning (HTP) is an important tool to improve the quality of hyperthermia treatment. It is a practical way of designing new hyperthermia systems and can be used to optimize the phase and amplitude settings to achieve optimal heating. One of the main challenges to be dealt with however is the uncertainty in the modeling parameters.(More)
BACKGROUND The aim of this study is preclinical evaluation of our newly developed regional hyperthermia system providing 3-D SAR control: the AMC-8 phased array consisting of two rings, each with four 70 MHz waveguides. It was designed to achieve higher tumour temperatures and improve the clinical effectiveness of locoregional hyperthermia. METHODS The(More)
Accurate treatment planning is necessary for the successful application of hyperthermia in the clinic. The validity of four different bioheat models or combinations of models is evaluated: the conventional bioheat transfer equation, the limited effective conductivity model, a mixed heat sink-effective conductivity model and a discrete vessel model. The heat(More)