A University of Alberta-led international study could change the standard method of diagnosis for prostate cancer patients, making the procedure more accessible, more affordable and easier for men around the world.
The team compared results from 802 men in eight countries who were suspected of having severe prostate cancer. Some of the patients received a biopsy guided by micro-ultrasound, some got a biopsy guided by magnetic resonance imaging (MRI), and some were scanned using both methods.
The researchers found that the micro-ultrasound produced similar results for less cost and in just one step compared with two required for MRI, which is the current standard of care. The results were recently published in the Journal of the American Medical Association.
"This study is paradigm-changing," explains lead author Adam Kinnaird, a surgeon with appointments in both urology and oncology who holds the Frank and Carla Sojonky Chair in Prostate Cancer Research funded by the Alberta Cancer Foundation. "Now there is another imaging device that can image prostate cancer so we can perform the biopsy in real time. The device costs less than an MRI and it can be done almost anywhere that you have electricity."
Even though MRI is the recommended standard of care, explains Kinnaird, it is often not accessible for patients in developing countries and even in rural settings in developed countries, because it is expensive and requires an expert to read the results. For example, in 2022, Kinnaird says just one-third of urban patients suspected of having prostate cancer in the United States received an MRI, and only a quarter of those living in rural areas did so.
The newly available micro-ultrasound offers 300 per cent better resolution than traditional ultrasound, which means medical staff can biopsy suspicious-looking prostate ducts right away, rather than waiting up to six months for MRI results.
"This provides level one evidence that can make a difference in care for patients," says Kinnaird, who is a member of the Alberta Prostate Cancer Research Initiative and the Cancer Research Institute of Northern Alberta. "It can improve wait times for patients without sacrificing accuracy or quality of the prostate biopsy."
Kinnaird expects micro-ultrasound to become the new standard diagnostic tool for prostate cancer within a couple of years.
The study was designed to need 1,200 patients, but Kinnaird says the results became obvious after just 802 men were tested and the trial was stopped due to early success. Serious cancer requiring treatment was found in 46.1 per cent of the micro-ultrasound group and 42.5 per cent of the MRI group.
About one in five of the patients came from Alberta because the U of A was able to join the study early thanks to equipment donated by the University Hospital Foundation.
"Because of the strength of the University of Alberta, with our equipment and infrastructure and our high volume of patients, we accomplished this in one year," Kinnaird says. "The patients were very altruistic in being willing to participate in a clinical trial."
Next steps for the research will include two new international trials: one to test the technology on patients who have already received a diagnosis of low-risk cancer and are undergoing active surveillance, and another to see whether the technology can identify patients who do not need a biopsy at all, thus avoiding the risk of infection. Kinnaird also plans to use machine learning to analyze the images and develop algorithms that can predict the location of prostate cancer.
The senior author of the paper was Laurence Klotz, a surgeon at the University of Toronto. The study was designed by the investigators and was funded by the Canadian company that makes the micro-ultrasound device, Exact Imaging.
