Hyperthermia aims at increasing the temperature of malignant tissues
to the range of 40-44 C. It is used adjuvantly to radiation therapy
in order to enhance tumour control and survival as was recently
demonstrated for pelvic tumours by the dutch deep hyperthermia group
(published in the Lancet, Van der Zee, 2000).
A major problem in quality assurance of hyperthermia is the
quantification of treatments. Both the duration and the level of the
temperature elevation contribute to the applied dose of a hyperthermia
treatment. A first requirement to quantify this dose is a description
of the full 3D temperature distribution.
Measuring by means of invasive thermometry does generally not yield a
representative sampling. An alternative for assessing the full 3D
distribution is the use of thermal modelling. To model heat transfer
in solids only conduction has to be taken into account. In vivo
temperature calculations also have to cope with convective heat
transport by blood. Cold blood enters the locally heated volume,
applies cooling, removes heat and by doing so can severely affect the
temperature distribution.
Modelling the thermal impact of blood can be done in several fashions
as will be discussed in more detail later on. Ideally all blood
vessels are taken into account individually. However in clinical
applications not all vessels needed for thermal modelling can be
reconstructed due to limited data acquisition. This thesis addresses
the problem of thermal modelling with incomplete angiographic data and
also the experimental validation of discrete vessel simulations.
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