By Sarah Seeley
Sept. 10, 2014
It was 2002 and William Whelan received an unexpected phone call from Fairway Medical Technologies in Houston, Texas. They were researching early cancer detection and wanted his help using their optacoustic imaging prototype.
Whelan has always had a fascination with the physics of the human body.
He received his doctorate in medical physics at McMaster University and for 12 years he researched biomedical optics as a member of the faculty at Ryerson University.
Whelan wasn’t familiar with optoacoustics, but after doing some research, he became captivated.
“It was very cool,” he said. “I found the ultrasound part of it fascinating.”
Optoacoustics involves a short pulse of light fired into cell tissue using a laser. The pulse is short so the tissue doesn’t heat up or burn. Instead, it expands and contracts, generating a sound wave. The waves are measured by an ultrasound transducer, similar to the ultrasound machines in hospitals.
Optoacoustic research is not new.
Alexander Graham Bell is known as the father of modern optoacoutics. In the 1880s, he experimented with short pulses of light and discovered that objects can generate sound waves.
A century later, researchers began applying Bell’s research in the fields of biomedicine, environmental science and even airplane repairs.
The first articles about optoacoustics were published in the 1980s.
Whelan brought his research and technology with him when he became the Canadian research chair of biomedical optics at UPEI in 2008. He worked with Seno Medical Instruments in San Antonio, Texas to conduct trials on men with prostate cancer. Whelan is the head of a research team, working with several graduate students.
“I think what’s most rewarding is the fact that I get to interact with my students who do all the real work in the lab and watch them grow and develop as young researchers,” he said.
Michelle Patterson is a researcher on the team. She joined the project as a part of her doctorate work in biomedical studies. She was intrigued by Whelan’s optoacoustic prototype.
“I thought it was a really neat machine and it had a lot of potential. I like a direct impact to society in my work. It’s really nice to see that impact on people.”
The team started its testing with tissue samples and lab-created synthetic samples. After hundreds of successful tests, they started in trials with 20 live specimens with prostate cancer. Her team discovered a difference in the frequency of sound waves between a cancerous and non-cancerous cell, Patterson said.
“I started playing around with the frequency of the signals and, to our amazement, we saw that the frequency from cancerous tissue is much higher than that of normal tissue.”
This process occurs because a cancerous blood vessel is smaller, denser and less organized than a healthy one so it sends a higher pitch than a healthy cell, said Patterson.
“What we found is, we were able to see the prostate cancer using the signal that came back.”
This is a big step for the future of cancer screening, said Patterson. Human trials have not been done at UPEI, but they are being done on breast cancer patients by Sano Medical in the U.S.
“In a clinical setting, the testing could tell the doctor a lot about the prognosis of the cancer, as well as what is the best treatment for that particular cancer.”
Optoacoustic testing has lower risks than a mammogram or an X ray because the light beam is not strong enough to burn tissue and there is no carcinogenic radiation involved, said Patterson.
“It’s completely external and it poses similar risks to an ultrasound.”
The testing will never replace the need for a biopsy, but it can tell whether or not a biopsy is necessary. If the project moves to human clinical trials, it could reduce the number of biopsies, because the optoacoustic imaging could determine whether the tumour was benign – non-cancerous, or malignant – cancerous.
A study done in Florida found 80 per cent of breast cancer biopsies come back negative, said Whelan. The numbers are relatively similar in Canada.
“In our earlier testing at UPEI we were able to detect the presence of benign tumours in the prostate, as well as malignant tumors.”
He is uncertain when testing might progress to human clinical trials because his team faces many road blocks in the medical community.
“One of the biggest challenges is trying to explain the technology to physicians and you must have physicians wanting and understanding the technology.”
He looks forward to the new discoveries his team will make as they continue their research.
“What has kept me involved for the past 12 years is the fact that it shows a lot of promise in being able to generate high quality medical images, and at some point being able to replace certain imaging procedures like CT scans.”
The UPEI team has published its work in the Journal of Biomedical Optics, Biomedical Express and several other scholarly journals.