Just because you can’t see it, doesn’t mean it isn’t there.
A new procedure currently in clinical trial at Sunnybrook is “smart biopsy” or “fusion biopsy” – so-called because it’s guided by an MRI (magnetic resonance imaging) scan fused with ultrasound imaging that puts a bull’s eye on prostate tumours.
Dr. Masoom Haider (pictured above), radiologist- in-chief at Sunnybrook, likens it to “a type of GPS navigation that gives a three-dimensional view.” A specialized MRI scan – superior to other imaging technologies for detecting and displaying tumours – is taken before the biopsy. The MRI is then fused with ultrasound imaging during the procedure. Lesions seen on the MRI scans are projected onto the ultrasound images to guide the biopsy needle to the best spot to ensure the cancer is not missed by the biopsy.
“The biopsy with MRI is very good at finding the aggressive cancers,” explains Dr. Laurent Milot, clinical and co-lead research radiologist at Sunnybrook. As part of the clinical trial and in the case of some other patients, Sunnybrook is already doing fusion biopsies. Dr. Milot explains that they are performed on patients where the presence of an aggressive prostate cancer is strongly suspected. Perhaps the cancer is hidden, having not been detected on previous conventional biopsies; or perhaps the patient is on active surveillance and has a low-grade prostate cancer, but his PSA begins to increase inexplicably.
The immediate benefit of the fusion biopsy is significant. “We can see exactly where the cancer is,” Dr. Haider explains. “You can see the prostate very well with ultrasound, but it gives a limited view of tumours.” The fused MRI scans will help pinpoint the tumours, making the procedure potentially quicker and more efficient, with much less needle sampling required.
Longer term, there is strong potential for this fusion imaging technology to actually guide the delivery of therapies for a better cure with less side effects.
Photograph by Doug Nicholson