Students

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Holly Stephens (supervised with Judith Pollard and Alex Santos)
Radiotherapy techniques for BCC and SCC of the eyelid
MPhil, Physics, University of Adelaide, commenced 2017

 

James Rijken (supervised with Scott Crowe, Jamie Trapp and Konstantin Momot)
Dosimetric accuracy for SABR spine radiotherapy treatments
PhD, Science and Engineering Faculty, QUT, commenced 2017 (part-time)

 

Candice Milewski (supervised with Scott Crowe and Rachael Wilks)
Effects of metal artefact reduction algorithms on computed tomography images
MRadiophysMed, Université Paris-Saclay, commenced 2017

 

Liting (Nancy) Yu (supervised with Jamie Trapp and Scott Crowe)
Developing new methods of dose evaluation for VMAT patient specific plans
PhD, Science and Engineering Faculty, QUT, commenced 2017 (part-time)

 

Samuel Peet (supervised with Scott Crowe and Jamie Trapp)
Out-of-field dose in contemporary radiation therapy
PhD, Science and Engineering Faculty, QUT, commenced 2016 (part-time)

 

Diana Binny (supervised with Scott Crowe, Jamie Trapp and Konstantin Momot).
Dose calculation, optimisation and quality assurance for Tomotherapy using statistical process control
PhD, Science and Engineering Faculty, QUT, commenced 2016 (part-time)

 

Trent Aland (supervised with Jamie Trapp)
Quality assurance of complex radiotherapy treatments
PhD, Science and Engineering Faculty, QUT, commenced 2013 (part-time)

 

Yongqian (Alan) Yin  (supervised with Scott Crowe and Steven Sylvander)
Investigation of interplay in IMRT treatments for breast cancer
MApplSci, Science and Engineering Faculty, QUT, completed 2017

A purpose-built, wax-cast humanoid phantom was constructed and attached to a moving phantom, to allow the effects of respiratory motion on breast radiotherapy dose to be measured. A range of treatment modalities (3DCRT with EDW, forward-planned (field-in-field) IMRT, invserse-planed IMRT, VMAT) were investigated and the dosimetric effects of interplay (positive and negative correlation) between MLC motion and respiratory motion were evaluated.

 

Andre Asena (supervised with Jamie Trapp and Scott Crowe)
Dose distributions in the vicinity of high-density materials in radiotherapy
PhD, Science and Engineering Faculty, QUT, completed 2017

This study involved the development novel dosimetry methods by which the effects of high-density/hign-Z medical implants on radiotherapy dose distributions could be accurately assessed. Radiochromic film and radiochromic gels were used to evaluate photon and electron beam dose distributions around a breast tissue expansion port, for a variety of different phantoms and beam geometries. After investigating the sources of uncertainty when radiosensitive gels are used in dose distribution measurements for implants suspended in the dosimeter, a simple correction method to improve the accuracy of radiotherapy dose distribution measurements under these circumstances. Additionally, a method was developed which allows for Fricke gel dosimeters to be used in conjunction with optical-CT scanning techniques for dose distribution measurements surrounding high-density materials, by using of custom 3D printed moulds to set cavities in Fricke gel phantoms to allow for the temporary suspension of high density implants in various geometries. This allowed for the high-density metal implant to be suspended during irradiation, and removed during imaging, circumventing the production of artifacts induced by missing ray-sum data and allowing accurate 3D dose measurements to be made, at distances as small as 1mm from the irradiated implant. The results of this research project have demonstrated the importance of evaluating the impact of high-density materials on radiotherapy dose distributions and provided severa useful methods y which such evaluations can be made.

 

Emma Splleken (supervised with Scott Crowe and Bess Sutherland)
Evaluating published film dosimetry methods
MApplSci, Science and Engineering Faculty, QUT, completed 2016

Over the last few years numerous authors have proposed methods for improving the uniformity, linearity and efficiency of radiochromic film measurements. This study attempted to replicate several of these methods and found that some methods produced accurate measurements, other methods were unreliable. Independent commissioning of film dosimetry techniques (as well as the film and scanning system) was recommended for centres considering adapting published methods for local use.

 

Somayeh Zolfaghari (supervised with Scott Crowe and Mark West, with substantial assistance from Dan Papworth)
Stereotactic radiosurgery for multiple brain metastases: a dose-volume study
MApplSci, Science and Engineering Faculty, QUT, completed 2016

Relationships between treatment plan dose accuracy, treatment deliverability, healthy brain dose (V12Gy) and the number and volume of brain metastses treated using a stereotctic radiosurgery technique were evaluated using radiochromic film measurements of test treatments planned for delivery to a head phantom with 4, 6, 8 10 and 12 simulated brain metastases. A method of two-dimensional “dose area analysis” was developed, in order to evaluate results.

 

Samuel Peet (supervised with Scott Crowe and Phil Back)
Estimating dose to cardiac pacemakers and cardioverter-defibrillators in radiation oncology patients
MApplSci, Science and Engineering Faculty, QUT, completed 2016

Measurements upstream and downstream of a cardiac pacemaker positioned realistically under bolus on a humanoid phantom were used to develop updated recommendations for estimating pacemaker dose from contemporary (complex, VMAT and TomoTherapy) radiotherapy treatments.

 

Paul Charles (supervised with Jamie Trapp and Scott Crowe)
Very small field dosimetry
PhD, Science and Engineering Faculty, QUT, completed 2015

The aim of this research was to investigate small fields, understand the physics behind them in a detailed manner, and improve on the accuracy small field dosimetry. The concept of reporting the measured dosimetric field size for each small field output factor measurement (as opposed to reporting the nominal field size) was investigated to see if inter-machine consistency could be improved. The field size at which the dosimetric field size was required for accurate output factor measurements was quantified by introducing the concept of a very small field. The physics behind very small field dosimetry was investigated, leading to a quantifiable theoretical definition of a very small field. The perturbations of non-water equivalent materials in very small fields were studied in detail, with a particular focus on air. The subsequent detailed understanding of these perturbations lead to the simulation based design of a new diode detector which, uniquely, responded the same in very small fields as in standard fields. These detectors were then physically constructed and tested to be accurate; and general recommendations for detector design for very small field dosimetry were established.

 

Kurt Byrnes (supervised with Trent Aland)
The effects of Cr-Co-Mo metal hip prosthetics on the dosimetry of a patient undergoing radiotherapy treatment
MApplSci, Science and Engineering Faculty, QUT, completed 2014

In this study, experimental (film dosimetry) measurements and Monte Carlo simulations were used to obtain data for evaluating, manipulating and improving the accuracy of dose calculations provided by two common, clinical radiotherapy treatment planning systems, in situations where radiation dose distributions were dramatically perturbed by the presence of high-density prosthetic implants.

 

Andre Asena (supervised with Jamie Trapp and Scott Crowe)
Evaluation of field size correction factors for optically stimulated luminescence dosimeters
Dean’s Scholars Honours Programme, Science and Engineering Faculty, QUT, completed 2012 (first-class honours)

This study examined and quantified the loss of measurement accuracy that can occur when using a single set of field size correction factors for optically stimulated luminescence dosimeter (OSLD) measurements of the radiation dose delivered by a matched group of clinical linear accelerators. Data obtained through this study will be used by the Australian Clinical Dosimetry Service (ACDS, ARPANSA) in the design of dosimetric intercomparison trials that will use OSLDs to establish the accuracy of radiation doses delivered at radiotherapy centres across Australia.

 

Muhammad Basim Kakakhel (supervised with Jamie Trapp and Andrew Fielding)
Monte Carlo simulations of dynamic radiotherapy treatments
PhD, Science and Engineering Faculty, QUT, completed 2012

The tumour motion during radiation delivery is a major impediment to the accurate targeting of radiotherapy treatments. This study used experimental measurements and Monte Carlo simulations to investigate the interplay effects of organ motion during dynamic radiotherapy treatments and provided important clinical recommendations for the safe and reliable use of enhanced dynamic wedges during radiotherapy treatments.

 

Shadi Khoei (supervised with Andrew Fielding and Jamie Trapp)
Extended Study of EPID Image Enhancement via Difference Imaging
MApplSci, School of Physical and Chemical Sciences, QUT, completed 2009

This project built on Tim Markwell’s thesis (below) in two important ways. Firstly, a more-complex virtual phantom was designed, to test the effect that modulation of the beam spectrum by different thicknesses of bone and tissue had on the results of the difference image analysis. Secondly, a series of experiments were completed to test the validity of these simulation results and verify the utility of the difference imaging technique, in practise.

 

Tim Markwell (supervised with Andrew Fielding and Jamie Trapp)
Contrast Enhancement of EPID Images via Difference Imaging
MApplSci, School of Physical and Chemical Sciences, QUT, completed 2008

With the goal of improving the image contrast available in megavoltage EPID images of radiotherapy treatments, this project proposed the use of a difference imaging technique that involves filtering out the high-energy signal, leaving an image composed from anatomy-sensitive kilovoltage photons. This project used Monte Carlo simulations to examine the likely effects of a range of modifications to the clinical EPID and suggested an ideal EPID-phantom configuration for image contrast enhancement.

 

Chris Poole (supervised with Andrew Fielding, Darren Cassidy and Phil Back)
Using Monte Carlo Simulation to Predict Dose at Extended Source to Surface Distance
MApplSci, School of Physical and Chemical Sciences, QUT, completed 2008

This study developed and analysed a method for using Monte Carlo simulations in the planning and verification of total body irradiation treatments. Because these treatments involve extended source to surface distances and consequently large simulation geometries, a large component of this project was focussed on analysing techniques for enhancing Monte Carlo simulation efficiency. Additionally, experimental measurements were taken and compared with Monte Carlo data to establish the accuracy and reliability of the chosen techniques.

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