On this page we are introducing another high achiever UWA graduate, Mr. Brendon Wright.
Brendon started his Master of Medical Physics at UWA in 2017. His research project was on “Investigation into the stability of On-Board Imaging during gantry rotation using advanced image processing methods” supervised by Dr. Pejman Rowshanfarzad, Dr. Ghulam Mubashar Hassan, Mr. Godfrey Mukwada and Adj/Prof. Martin Ebert.
Immediately after graduation, Brendon was accepted as a radiation oncology medical physics registrar and started his 3-year clinical tanning through TEAP at the Department of Radiation Oncology in Canberra Hospital, ACT.
Here are comments on Brendon’s performance from his Supervisor and the Medical Physics Program Chair, Pejman Rowshanfarzad, “It was a pleasure to be Brendon’s project supervisor, teacher and coordinator. His presence of mind and programming ability were impressive. Brendon seemed to enjoy studying medical physics and his marks in course units were among the highest. Brendon’s research outcome was highly satisfactory. He introduced a new method for improved quality assurance in radiotherapy patient positioning system. Brendon has published his work in Biomed. Phys. Eng. Express ”.
And here are comments from Brendon’s clinical supervisor and Director of Physics Research at SCGH, Prof. Martin Ebert: “Brendon’s project required combining an in-depth understanding of the systems used to treat cancer patients with radiotherapy, with image-analysis methods from computer science. To do this, Brendon had to coordinate measurements on the systems with clinical physics staff and collaborate with computer scientists to develop analysis methods. Within the time available for the project, Brendon was able to develop those methods and apply them to providing highly precise characterisation of treatment devices, paving a way for implementing his method throughout the world. This is a great beginning to what we expect to be an exciting career in medical physics.”
Brendon kindly accepted to answer a few questions about his experience in our Medical Physics research Group.
Introduction and your current position and role:
Hi, I am Brendon Wright and I am a recent graduate from UWA’s Master of Medical Physics course, completing it at the end of 2019. I am currently working at the Canberra Hospital in their Medical Physics and Radiation Engineering Department as a Radiation Oncology Medical Physics Registrar.
What did you enjoy most about UWA, and Medical Physics research group?
UWA provided me with immense opportunities for practical experience whilst undergoing my coursework, with a massive amount of support given to myself and my peers by the Medical Physics research group. Weekly research meetings gave the opportunity for me and others to present our work over the previous weeks and to gain as well as provide feedback. The course is taught from people with immense experience in the field who are specialised in the topics that they lecture you in, giving an accurate picture of the work you will do after you graduate.
Can you give us your top three reasons to study Medical Physics?
- The practical experience that you gain throughout the course.
- The research undertaken is at the forefront of the field, meaning you are helping to make a difference even whilst completing your masters.
- The reward of studying something challenging but being able to understand and excel in it.
How do you feel you have made a difference in your field of research?
My masters project allowed me to delve deeply into the mechanical accuracy of imaging systems used before patients are treated using radiotherapy. I feel that this work could help to improve the accuracy of the treatment patients receive in the future, and, as a result, improve their quality of life afterwards.
What is your best advice to current students and Medical Physics applicants?
Listen to your peers and the lecturers about how to stay on top of your coursework and what to prioritize and make the most of all the opportunities which are presented to you during the course. Those around you want to help you get everything possible out of the course and if you heed their advice and take the opportunities given then you will be setup well for the future and to make a positive impact in the field.
Here is the abstract of Brendon’s thesis:
Introduction: The quantification of geometric errors associated with radiotherapy are an important part of any quality assurance procedure that exists, with Image-Guided Radiotherapy (IGRT) used as a method in order to reduce the impact of this error. In order to determine the accuracy and stability of linear accelerators during arc delivery, phantoms are placed at different locations on them, with images acquired of these phantoms and image processing techniques used. The study compares two different image processing techniques in terms of accuracy and precision, with the better performing algorithm being used to determine the stability of the kV and MV imaging systems of multiple linear accelerators during arc delivery, and thus quantifies the accuracy of the IGRT systems used prior to or during treatment.
Methods: A comparison was done between the Optical Flow algorithm and the Hough Transform by comparing pairs of images taken with the kV imaging panel moved laterally. Phantoms were attached to the kV Source and MV source, with a Winston-Lutz phantom placed at the isocentre using room lasers. The positions of ball-bearings in the corners of the phantoms was then used to determine the source sag and panel sag in each plane. Images were taken at multiple points during gantry rotation in order to assess the movements during a single arc, with data taken during rotation in both a clockwise and counter-clockwise direction.
Results: The Optical Flow algorithm was found to perform better than the Hough Transform. Data was taken from an Elekta Axesse, a Varian Trilogy, and a Varian TrueBeam. It was found that the TrueBeam was the most stable and accurate linear accelerator and the Trilogy the least stable and accurate. There was a noticeable error with the kV data from the TrueBeam linear accelerator when the source was covered, and there was a significant difference when the source was uncovered. The kV data was found to be inconsistent when comparing a clockwise and counter-clockwise rotation.
Conclusion: A quantitative assessment of the stability of the kV and MV imaging systems is important to conduct in order to determine the accuracy of any machine used in radiotherapy. Information about the kV source position during rotation can be used to increase the image quality of kVCBCT reconstruction, and difference in movement due to rotation direction should be investigated further in order to determine the cause. It is suggested that all centres perform this form of QA on a quarterly or yearly basis, and any SBRT/SRS therapy that is due to take place be performed on the best performing machine from this QA.
Part of Brendon’s work entitled “Comprehensive investigation into the stability of Varian and Elekta kV imaging systems during arc delivery” is published in Biomed. Phys. Eng. Express, and is available through this link.
Find out more about the program in our website (Courses, Projects, Students, Available jobs, …)
