Every single day, an average of 14 men in Canada die of prostate cancer. This startling number has driven researchers to do something about it.
As with all cancers, early detection can lead to less aggressive and more successful treatment, but current diagnostic methods are problematic. Men deemed at-risk undergo a series of tests, including bloodwork and an MRI. If the results are concerning, the next step is typically a targeted biopsy, during which doctors use an ultrasound probe to essentially "guess" where the MRI-identified lesion may be and insert a needle into the prostate to take a tissue sample for analysis.
A negative biopsy does not mean the patient is cancer-free, however. It could be because the wrong location was sampled. One or several more biopsies often follow an invasive and costly procedure.
"There's a lot of uncertainty in this clinical pathway," says Carlos Rossa, a Systems and Computer Engineering researcher at Carleton University.
"There's anxiety for patients, and repeating biopsies is far from ideal."
This challenge is why Rossa and a multidisciplinary team, including Carleton researcher Andy Adler and Dr. Nicola Schieda at The Ottawa Hospital, have embarked on an ambitious project to develop a more accurate diagnostic tool.
"We're working on a way to determine whether the needle has been placed in the right location before a sample is taken," explains Rossa. "This is a fundamentally new approach to imaging specifically designed for prostate cancer."
A New Imaging Frontier
In simple terms, the Carleton-led team is attempting to convert a regular surgical needle into an imaging tool by equipping the instrument with a sensor that can measure the acoustoelectric properties of the tissue it's passing through.
When cancer develops in the prostate, the water content of tissue changes, altering its electrical properties. A sensor at the tip of a needle can be used to determine whether it is entering healthy tissue or a lesion.
At the same time, if the prostate is being exposed to localized ultrasonic pressure, tissue will compress and expand, providing the sensor with acoustic data that can be translated into a tomographic image or "map" that reveals whether and precisely where there is cancer.
"Anything abnormal in the tissue should show up," says Adler, who is also in Systems and Computer Engineering.
"Doctors are already inserting a needle and doing an ultrasound. We want to provide them with more information."
This project is being supported by the federal government's New Frontiers in Research Fund, which encourages high-risk, high-reward research.
The reward is obvious: better outcomes for patients and less strain on our health-care system. But there are a lot of intricate physics puzzles to address for the technology to be effective.
"The magnitude of the measurements we're looking at is about 10 billion times smaller than the magnitude of the voltage in an electrical outlet," says Rossa.
"We're looking for tiny signals in an environment that has a lot of electrical noise, then have to convert these signals into images. The risk comes from the fact that nobody has ever done this before."
From Diagnosis to Treatment
The group collaborating on this research has expertise in biomedical, electrical and computer engineering, with crucial direction from clinicians at The Ottawa Hospital.
Although prostate cancer is the focus, it has potential applications to other conditions, such as breast and liver cancer, and could also improve cardiologic imaging. "Anywhere you use needles, catheters or ultrasound could benefit," says Adler.
While diagnosis is the initial thrust, this methodology could also guide treatment.
"One of the main therapies for prostate cancer is using needles to deliver radioactive seeds' near the lesion," says Rossa.
"The seeds destroy the cancer cells, but you're subjecting all of the tissue to this radiation instead of concentrating the dose in the lesion because you can't reliably tell where the lesion is with ultrasound. If we can generate a tissue map, we can concentrate the radiation in specific locations."
The researchers hope to validate their technology on prostate tissue that has been removed from patients at The Ottawa Hospital within the next year and continue moving from the lab toward clinical deployment.
"We hope that through this exciting technology we can provide more accurate needle biopsy diagnosis of prostate cancer for our patients," says Dr. Schieda, "potentially reducing time to diagnosis and treatment, eliminating the need for repeat biopsy and ultimately improving outcomes."
