Masters (or Honours) Medical Physics Research Projects for 2015
For more information or to get in touch with supervisors contact Mike House
michael.house@uwa.edu.au
Title
Key Focus Area
Supervisors
Project Type
Project Outline
CT Image Quality and Interpretability in the Lungs
Title
Linear accelerator shielding - impact of long-term
irradiation
Key Focus Area
Supervisors
Project Type
Project Outline
Radiation Safety
A/Prof. Martin Ebert (SCGH), A/Prof. Michael House (UWA)
Experimental/Analytical
Bunkers housing linear accelerators at the Sir Charles Gairdner
Hospital (SCGH) have been in use for approximately 40 years. The
incident high-energy photons and neutrons will have induced
transformations in many nuclei in the shielding materials. These
bunkers are being vacated and we have an opportunity to examine
these transformations, which may have implications for the design of
future facilities. Samples of materials, including wall plaster, fittings
and concrete core samples, will be obtained from sections of bunkers
that have received sustained irradiation. The elemental and isotopic
composition of the materials will be determined by mass spectrometry
(and possibly ion probe imaging). For surface materials, these will be
compared with samples from non-irradiated regions of the hospital that
were installed at a similar time. For core concrete samples, the profile
of composition with depth in the wall will be related to the expected
attenuation of radiation with depth in the material. Any measured
changes in composition will be examined relative to the useage history
Radiology
Prof. Stephen Stick (TKI/PMH), Tim Rosenow (TKI)
Analytical/Experimental
Cystic fibrosis (CF) is the most common life-shortening genetic
disease in Australia. In CF, chronic lung disease is the most severe
and important result of this genetic defect, causing the majority of
morbidity and mortality. This lung disease begins at birth and
progresses throughout life, eventually leading to respiratory failure.
Currently CT scans are the most sensitive measure of lung disease,
and often the only respiratory abnormality detectable in infants and
young children. However, each practice does their own thing with
radiation dose and image quality, so the beginnings of some kind of
standardisation are an important step in reducing radiation dose
across the world. This project will look at the effect of CT dose and
other imaging parameters on image interpretability, particularly in the
lungs. Using a large set of human chest CT scans with a range of
abnormalities and disease severity, the aim of the project will be to
develop a model of noise in CT images of the lungs introduced by
variable dose and CT settings. The model could then be used to
systematically introduce noise to CT images and look at the
interpretability of the image, both with numerical metrics and
subjectively with the input of a radiologist.
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of the bunker, the spectra of radiation used during that time and the
interaction cross-sections for radiation with particular nuclei.
Title
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Project Outline
Title
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Supervisors
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Project Outline
3D Dosimetry for Complex Radiotherapy Plans
Radiology/ Radiotherapy
A/Prof. Michael House (UWA), A/Prof. Pejman Rowshan Farzad
(UWA)
Experimental/Analytical
3-D radiation dosimetry is an important technique for measuring the
complex dose distribution that arises from modern radiotherapy
treatments like the Cyber Knife. However, our ability to measure
complex doses routinely in the patient setting requires improvement
and refinement. Experimental approaches to measuring dose
distributions are necessary to validate the widely used computational
simulations based on Monte Carlo simulations. The aim of this
research project is to develop a suitable gel phantom for radiotherapy
dosimetry and image the phantom using a variety of quantitative MRI
approaches to map the 3-D dose distribution. The project will
determine the accuracy of image-based dosimetry through comparison
against simulated dose distributions and conventional dose
measurements (film, ion chamber, TLD, solid state devices). These
experiments should help to improve the utility of imaging to map
complex dose distributions in the clinical setting.
Radiotherapy enhancement with gold nanoparticles
Radiotherapy
A/Prof. Martin Ebert (SCGH), A/Prof. Pejman Rowshan Farzad (UWA),
A/Prof. Michael House (UWA)
Experimental/Analytical
Gold nanoparticles have been shown to increase the radiosenstivity of
cancer cells by providing a greater interaction cross section for the
photon and the production of short-range electrons which lead to an
increase in DNA damage. To safely and effectively use gold
nanoparticles, we need to investigate and quantify the enhanced
impact of radiation caused by them. This project will involve the
development and characterisation of gold nanoparticles, cell culture
experiments to show possible evidence of any revival and to validate
that the tumour cells have been destroyed, radiobiological modelling to
link nanoparticle characteristics, energy deposition and biological
response and Monte Carlo modelling of x-ray interaction with gold
nanoparticles. Through these experiments we hope to gain a better
understanding of how gold nanoparticles can be optimised for clinical
radiotherapy.
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Title
Human-analogous radiotherapy treatment planning on a
small-animal treatment unit
Key Focus Area
Supervisors
Project Type
Project Outline
Radiotherapy/Radiology
Prof Martin Ebert (SCGH)
Analytical/computational
Human radiotherapy involves the precise (mm-scale) delivery of
radiation beams with complex configurations, and the resulting dose
distributions can be matched to spatial variations in anatomy and
organ function. In preclinical studies, devices capable of mimicking
human radiotherapy are available, with one such device being installed
at the Telethon Kids Institute in late 2015 (TBC). This project will
involve investigating the range of irradiation techniques, capabilities for
dose manipulation and level of analogy with human irradiation that can
be achieved with this system. With early access to the associated
computerised planning system and a sample mouse image set, the
capabilities of irradiation will be assessed across the range of available
irradiation methods. Assessment will be made of the dose statistics
that can be derived from the resulting plans, and an investigation will
be made of uncertainties in the underlying dose metrics.
Title
Radiotherapy treatment planning based on voxel-level
probabilities
Key Focus Area
Supervisors
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Project Outline
Radiotherapy
Prof Martin Ebert (SCGH)
Theoretical/analytical/computational
Radiotherapy treatment planning is currently based on a volumetric
model of human anatomy; organs and targets to be treated are
considered as 3D (maybe 4D) structures extending over many
millimetres. This limits the way that information can be incorporated
into the treatment planning process. Such information could include
functional imaging and spatio-temporal variation in sensitising agents
and adjuvant therapy agents, statistical models of response based on
the outcomes of previous patients and the data used to inform
treatment, and biological response mechanisms that incorporate
spatial and temporal cross-correlation. This project will involve building
mathematical models that can incorporate complex, probabilistic
information on treatment and response, into the planning process and
methods for using that information to drive patient treatment planning.
Experimental data will be available for treatment of prostate cancer
that will form the basis of a test set for the developed methods.
Title
Combined ferromagnetic/high-Z nanoparticles for
image-guided radiotherapy dose enhancement
Key Focus Area
Supervisors
Project Type
Radiotherapy/Radiology
Prof Martin Ebert (SCGH), A/Prof Mike House (UWA)
Computational
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Project Outline
Gold nanoparticles have been shown to increase the radiosenstivity of
cancer cells by providing a greater interaction cross section for the
photon and the production of short-range electrons which lead to an
increase in DNA damage. Ideally, we would be able to image the
distribution of such nanoparticles in a patient at treatment, in order to
ensure the tumour is adequately covered and that the nanoparticles
are not concentrating within sensitive healthy tissues. If a
ferromagnetic material could be combined with a high-Z material into a
nanoparticle, we could achieve both of these aims. This project will
involve simulating hypothetical combined-material nanoparticles with
the Monte Carlo package Geant4. Initially, a pure gold nanoparticle will
be simulated, followed by various combinations of iron (e.g., mixture,
gold shell, side-by-side) in order to observe the impact on generated
secondary electron yields.
Title
Spatial mapping of dose, treatment toxicity and
treatment success in radiotherapy
Key Focus Area
Supervisors
Project Type
Project Outline
Radiotherapy
Prof Martin Ebert (SCGH)
Analytical/computational
When a patient is treated in radiotherapy, radiation dose is delivered to
a ‘target’. This target is meant to represent the tissue to be treated, but
may not. To get the dose to the target, it is also necessary to deliver
some dose outside of the target. In this project, real data from a clinical
trial will be used to map changes in radiation dose throughout a patient
anatomy to the likelihood of the success of dosing the real tissue to be
treated, and the likelihood of causing damage (‘toxicity’) to tissues
outside of the real target. This will involve taking co-registered patient
datasets, developing algorithms for combining their dose distributions
and statistically mapping that dose to treatment success or toxicity.
Title
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Project Outline
Spatial dose-response in kidney
Radiotherapy/nuclear medicine
Prof Martin Ebert (SCGH), A/Prof Mike House (UWA)
Analytical/computational
When using radiotherapy to treat patients with abdominal cancers, the
kidneys typically receive some radiation dose. The pattern of dose
across the kidneys can influence any damage caused to them, with the
spatial distribution of kidney function impacting on that dose-response.
We have functional image data (SPECT) for a number of patients
treated for abdominal cancers that will allow us to investigate that
spatial dose-response relationship. This project will involve taking coregistered radiotherapy dose and SPECT function information and
examining the relationships between dose and function, with the aim of
developing a model of spatial dose-function response in kidney.
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