"Modelling of nonlinear high-intensity focused ultrasound propagation
for cancer therapy"

Paul Godden, Therapeutic Ultrasound Group, Joint Department of Physics,
Institute of Cancer Research & Royal Marsden NHSF Trust

Abstract: Mathematical modelling of high-intensity focused ultrasound
(HIFU) propagation for clinically-relevant situations, such as the
non-invasive treatment of tumours in organs such as the liver, presents
a series of technical challenges. Initial conditions can comprise
several hundred independent sources, all of which drive
highly-oscillatory wave motion. Further, propagation through multiple
tissue and fluid layers necessitates consideration of wave propagation
through regions of differing  heterogeneity. Attenuation, scattering and
refraction of the sound beam also requires careful mathematical
treatment to ensure accurate solutions for the time-dependent thermal
distribution in the treatment region.

In this presentation, much of the emphasis will be upon describing the
essential physics of the clinical problems, rather than formal analyses
of the simple numerical methods currently used. The current HIFU
transducer and wave-propagation models being developed at the ICR will
be presented, intended as a point of departure for discussion regarding
the technical aspects of current and future work.