A team of researchers is finding new ways to diagnose, target and treat cancer, with better patient outcomes.
To harm or to heal? This was the choice for a young Anatoly Rozenfeld, a graduate of the prestigious St Petersburg Polytechnic Institute and the Kiev Institute for Nuclear Research.
He’d studied under some of the leading minds in fields of theoretical physics, experimental radiation and nuclear physics. During the 1980s, nuclear physics in the former Soviet Union was diverging into two major fields: fundamental physics research on particle accelerators; and an emerging field that used its destructive capability as a medical tool.
“My mum passed away from a brain tumour when I was 10 years old so I pretty much grew up without a mother but with a decent father ,” Professor Rozenfeld recalls. “She was 34 at the time and she was a medical doctor herself. In the 1960s in the Ukraine there was no advanced radiation imaging for cancer diagnostic and medical treatment for cancer.”
His father, an engineer who later emigrated to the United States, also died of cancer at a relatively young age 79. “When I left Ukraine I decided I should work in this newer field and use my skills and knowledge in medical radiation to help people. This became my vision.” He began to build on his vision when he joined UOW in September 1993, where he immediately set about building UOW’s capability in medical radiation physics.
More than twenty years later, Professor Rozenfeld is a Distinguished Professor and Director of UOW’s Centre for Medical Radiation Physics (CMRP), where his team more than 100 research students, researchers and adjunct staff are attacking the biggest idea in cancer diagnosis and treatment: making cancer treatment safer and more effective, hitting only the cancer cells with the right dosage to destroy them and not the healthy cells nearby.
Despite the ongoing advances in radiotherapy cancer treatment, uncertainties in accurately defining the area to irradiate and calculating the radiation dosage required to adequately treat a tumour can result in malignant cells being missed or the patient being delivered too large a dose, killing healthy cells. “Currently around 50 per cent of cancer patients are treated with radiotherapy,” he explains.
“Current treatments are very accurate but also complex, and more complexity increases the potential for error.” The ‘magic wands’ the CMRP researchers wave are new-generation devices and technologies to detect radiation, which they apply to better diagnose and treat cancer. Don’t be distracted by the highly sophisticated physics and mathematical modelling.
For many of these researchers, the work has deep personal significance.
Hitting the bullseye
PhD student Lauren Bell (pictured above) uses a sporting metaphor to describe the complexities in cancer radiotherapy. “If we were archers, we could hit the same point on the target every time with our bow and arrow,” she explains. “But, are we hitting the mark?
“Without methods to account for these uncertainties we risk delivering ineffective treatment and significant toxicities. How well a patient recovers is directly related to the radiotherapy treatment hitting all the malignant cells.”
Cancer specialists rely on a combination of scans and imaging to detect the outline, or contour, of the tumour. This is easily done when the scans reveal a clearly defined tumour, yet, even high-quality imaging cannot reveal the microscopic detail of the tumour and its exact breadth and depth remains difficult to define.
Using data sets based on previous patient scans, Lauren’s research is helping to improve the accuracy of the radiation required to treat the disease, reducing the margin of error, or uncertainty, doctors face where imaging lacks the detail to accurately define the shape and size of the tumour. Lauren’s work involves precisely calculating a region that’s a little larger, ensuring all the cancer cells are destroyed.
The margin takes into account the differing assessments of multiple clinicians, and using probability maps, calculates the contour of the tumour. The contouring technique also saves valuable clinician time as well as increasing the likelihood of the patient receiving successful radiotherapy treatment the first time and with potentially fewer follow-up courses of radiation.
While we continue to develop ways to precisely deliver cancer destroying radiation to where we want, we can’t be certain we are accurately hitting the target.Lauren Bell
Her journey to becoming a leading researcher in removing the ‘weak link’ in cancer treatment can be traced to her childhood when her younger sister Rachael was diagnosed with Acute Lymphoblastic Leukaemia at age 9. During the next two years of Rachael’s treatment, Lauren frequented hospitals with her family, leaving a lasting impact on her future choices.
“I think because we were all so young, it had a big impact on shaping who I am today,” Lauren says. “I guess I didn’t fully grasp the concept of cancer and how sick Rachael was, because I remember the visits to hospital as exciting times rather than sad or scary.”
Lauren’s work – under the supervision of Professor Peter Metcalfe from CMRP and Associate Professor Lois Holloway, Research Leader at Department of Radiation Oncology at Liverpool hospital – is expected to directly contribute to successful radiotherapy treatment for cancer patients, translating to patients living healthy, happy and cancer-free lives for longer.
A ‘magic plate’ that protects patients
While Lauren’s work is ensuring the radiation hits the treatment bullseye, calculating the dosage of radiation on human tissue remains a complex task for medical physicists. Ziyad Alrowaili (pictured above), a PhD student with CMRP, has spent the past three years working on a simple and elegant solution for a serious issue: how to precisely measure the amount of radiation a patient receives during cancer treatment.
The end game is the ‘magic plate’ radiation detector that will help improve the safety of cancer radiotherapy. A treatment plan for one patient may contain thousands of parameters defining the variables involved, and this complexity makes it imperative that processes are in place to check and verify the x-ray equipment delivers the dose accurately.
Even with the layers of safeguards already in place to reduce the risk to the patient, the concept of measuring the radiation dose distribution as it is delivered is elegant and appealing to clinicians.
Nobody in the world has yet managed to develop a simple, cheap and effective way to calculate the radiation dose while the patient is being treated, yet it’s a vital part of patient wellbeing.Ziyad Alrowaili
The ‘magic plate’ consists of an arrangement of silicon radiation sensors, sandwiched between plastic sheets less than 1-millimetre thick, that measure the radiation dose during treatment with real-time results. The magic plate detector sits in the radiation path and before the x-ray beam hits the patient, records millisecond by millisecond a 2D map of the intensity of the radiation beams.
An algorithm Ziyad has developed determines the dose reaching the patient based on the measured intensity of the x-ray distribution in the beam. This can then be checked against the planned dose and if they disagree, the treatment could be automatically and immediately stopped.
“The magic plate detector could be attached to the linear accelerator during patient treatments so that it can continuously record a 2D map of the radiation dose being delivered for comparison with the intended dose plan,” he said. “The result is a method that could be used to ensure patient treatment safety and accuracy on a day-to-day basis with minimal workload impact for clinicians.”
Ziyad, working alongside Dr Martin Carolan, Director of Radiation Oncology Medical Physics at the Illawarra Shoalhaven Local Health District, and academic supervisor Associate Professor Michael Lerch, found the plate did not interfere with the quality of the treatment and accurately recorded in real-time the transmission of the radiation beam.
“We have all heard tragic stories or know someone who has had cancer. Personally, the magic plate has a symbolic meaning to me, as it inspires me to develop new ideas that can continue to improve cancer treatment around the world,” Ziyad says.
“My hope is that this work is a way to support the doctors and oncologists working in hospitals treating cancer patients. This type of research would have a real impact in my home country of Saudi Arabia and I’d like to be a part of pioneering such a development.”
The next frontier
When Professor Rozenfeld and his colleagues first set out in 1993 the focus was on better understanding the physics of radiation therapy. They have since developed a deeper understanding of the field of radiobiology, invented and patented tools for measuring the dosage and put that knowledge in the public domain. The next step is applying that knowledge to specific patients in the quest for personalised medicine.
“The marriage of nuclear physics, radiation physics, imaging and radiobiology enables us to better understand the individual organism and how it reacts to radiation,” Professor Rozenfeld says. “This will help us understand and predict the effect of radiation for a specific patient. This is very important.
“At the moment patients are all getting the same radiation therapy treatment. Yet, every single person’s body is different and we need to understand the biological peculiarities so the treatment is tailored to the patient.”
Professor Rozenfeld is optimistic about the challenge that presents. “When I go and speak to students at high schools about their study options, I don’t talk to them about the complexities of physics. The first question I ask students is: ‘do you want to help people?’ Our health is the most important thing we have. Then I explain how physics can help people.
“With drive and support, they have a unique opportunity to make a difference in the world.”