Graduate Student, Physics
PhD student
Thesis Title: Ultrasound transducers to create controlled mild hyperthermia in deep body solid tumours to support Radiotherapy
About
Clinical trials of mild hyperthermia on surface and intra-cavitary tumours as part of radiotherapy and/or chemotherapy treatments for cancer have shown significant improvements in outcome. The technique involves selectively heating the tumour, but not the surrounding tissue, to a temperature of about 43oC for a period of up to an hour. Currently, solid tumours deep within the body are deemed unreachable by mild hyperthermia as there is no method of producing the selective heating necessary. Previous work in Warwick has resulted in a novel phased array ultrasound transducer based on a random distribution of elements which has the potential to create mild hyperthermia deep within the body. However, simulations in homogeneous media and measurements in acoustic tanks revealed high intensity regions beneath the elements and a sensitivity analysis revealed problems with non-piston like behaviour of the elements. The early stages of this work will focus on better understanding and overcoming these problems, in particular the potential for using a laminar flow layer between the transducer and the skin to prevent localised heating beneath the elements. To date, all the work has been based on low intensities and homogeneous media. In this project we aim to increase the ultrasound intensities to the level that would be required for clinical use and examine both analytic and numerical solutions to the problems of focussing and steering the beam in inhomogeneous media such as the multiple tissue types and their interfaces that the would pass through if used clinically. To validate the model predictions, test cells will be created that can contain inhomogeneous media and temperature rises will be measured using arrays of thermocouples embedded at known points in the media. The geometries for numerical simulations will come from MRI & CT scans of the phantoms which mimics the data used for radiotherapy treatment planning.
Contact Information
Room#P220
Medical Physics, Dept of Physics
University of Warwick
Coventry CV4 7AL
0044 (0)77 8461 6743
0044 (0)247 65 74 207
