MRI before biopsy for prostate cancer: agreed. But which technology? BPC surgeon Alan Doherty reflects on key developments at the annual conference for urologists.

Cyberknife MRI For Prostate Cancer

By Alan Doherty, consultant urologist and founder of the Birmingham Prostate Clinic

The annual meeting of the British Association of Urological Surgeons always provides a valuable bellwether for key developments in prostate cancer.

I attended this year’s meeting in Liverpool at the end of June and one theme particularly stood out: the use of MRI scans in the diagnosis of prostate cancer before proceeding to a biopsy.
There was much interest and discussion in a major trial, called the PROMIS study, which compares the effectiveness of multi-parametric MRI scans in assessing whether a biopsy is required and in identifying prostate cancer. The study, which involves more than 700 men, is anticipated to show positive results for multi-parametric MRI scans compared with the standard TRUS biopsy (trans-rectal ultrasound).

From the perspective of our practice at the Birmingham Prostate Clinic, there was certainly assurance from this: for more than four years, our diagnostic pathway has been based on multi-parametric MRI as the next step, after suspicion of prostate cancer is raised by PSA test and physical examination. We have long advocated MRI scan before proceeding to biopsy and work with the highly respected consultant radiologist Dr Ian McCafferty.

However, I have always been cautious about any sense of satisfaction and complacency, especially in a field such as prostate cancer, and true to form, the meeting provided plenty to reflect on. While there is a solid body of evidence that MRI before biopsy is the best diagnostic pathway, there is no consensus on what type of MRI provides the greatest level of accuracy and how we can best combine imagining technology with the biopsy itself.

The meeting included discussions and presentations on no less than four different advanced approaches: MRI-ultrasound fusion (sometimes called Fusion biopsies), cognitive, systematic and template biopsies. There was also discussion about the relative merits of the way we set up a biopsy; the traditional trans-rectal versus the trans-perineal approach, which is increasingly used with the new imaging technology. Further still, there was discussion of a promising technology called histoscanning, measuring how compact tissue is, working on the principle that cancerous tissue has a much higher density than ordinary tissue.

I see many patients at the Birmingham Prostate Clinic who are extremely well informed and often come to us as result of their own research. They know the issues: the TRUS biopsy is notoriously hit and miss in terms of identifying prostate cancer and equally, that if PSA is raised, proceeding immediately biopsy is neither best for the patient nor for the diagnostic process. But how, as a patient, to weigh up the new MRI and biopsy approaches, when there is no professional consensus?

I would suggest some key principles. Any man referred to a urologist with an elevated PSA should ask whether MRI is offered before biopsy and what kind of biopsy will be carried out. Equally, beware the enthusiast: if your urologist is promising a new type of assessment will be a game changer with a higher level of accuracy than any other, you are entitled to ask for the evidence and to know how long he or she has personally used that technology.

At the Birmingham Prostate Clinic we have many years of evidence from and experience of multi-parametric MRI scans, which we use before biopsy to inform whether to move to the next stage in the diagnostic process. We have six years of experience with the PCA3 test which has proven to be a highly accurate risk predictor for prostate cancer. We selectively use template biopsies and pay very close attention to family history. We have seen some very valuable information coming from PSMA scans.

In other words, we evaluate every emerging diagnostic tool as a new potential piece in the prostate cancer jigsaw puzzle: no single assessment will provide the answer, it is necessary to weigh up the information from each measure carefully and cohesively.