MRI improves detection of prostate cancer Prostate biopsy no longer necessary for 50% of male patients

4 December 2018

There is good news for the more than 40,000 men per year who go to the hospital for diagnosis because of elevated Prostate-Specific Antigen (PSA) levels. With a negative MRI diagnosis, ultrasound-guided prostate biopsies will no longer be required. This is the result of the 4M study, which is published today in European Urology. “Thanks to the use of MRI, we can reduce the number of prostate biopsies by half,” says Jelle Barentsz, Professor of Radiology, who led the study. The new guidelines for diagnosis of prostate cancer, to be published in early 2019, will include the use of MRI.

The current guidelines for the diagnosis of prostate cancer prescribe ultrasound-guided prostate biopsies to determine whether cancer is present in patients with elevated PSA levels. In this process, pieces of tissue are removed from twelve locations in the prostate. However, prostate tissue can be evaluated more accurately with an MRI scan. Consequently, patients with a negative diagnosis for prostate cancer based on the MRI scan do not have to undergo a prostate biopsy. In 2017, Radboudumc therefore replaced the ultrasound-guided prostate biopsy with an MRI scan to diagnose men with elevated PSA levels.
 
Three centers
To test the use of MRI in prostate diagnostics nationwide, the 4M study (Met prostaat-MRI Meer Mans) was performed between 2015 and 2017 under the supervision of PhD candidate Marloes van der Leest. This study was funded by Alpe d’Huzes. At three centers in the Netherlands, the MRI diagnostic method was compared with the ultrasound method in 626 men with elevated PSA levels. All men first underwent an MRI scan to evaluate whether cancer was actually present. This scan showed that approximately half of them had indications of high-risk cancer. These men then underwent a MRI-guided prostate biopsy, in which two to four pieces of tissue were taken.
 
Less unnecessary treatment
To compare the results of the MRI diagnosis with the standard practice of ultrasound-guided biopsy, all participants underwent both methods. With MRI diagnosis, fewer low-risk forms of cancer were mistaken for high-risk cancer. This means that the MRI method can largely prevent over-diagnosis and unnecessary treatment of prostate cancer.
 
Twelve-needle biopsy no longer required for most patients
The results of the study showed that the MRI method is just as reliable as the standard – but more invasive – ultrasound-guided method. And that is good news for patients, says Professor of Radiology Jelle Barentsz: “With this method, approximately 20,000 men per year can avoid the 12-needle prostate biopsy. Patients with elevated PSA levels who do not present with a high-risk form of cancer on the first MRI scan do not have to undergo a biopsy, but must continue to monitor their PSA levels.”
An ultrasound-guided prostate biopsy will follow only if a doctor strongly suspects high-risk prostate cancer despite a negative result from the MRI method.
 
Specialized centers
In the Netherlands, patients with elevated PSA levels and a suspicion of prostate cancer are referred by their GP to one of the specialized prostate diagnosis centers in the Netherlands. “At these centers, doctors specialize in performing MRI prostate scans. As a result, prostate biopsies can be avoided in 49% of the patients. However, for patients who are referred to non-specialist centers, this figure drops to 28%,” explains Barentsz.  The recommendations from the 4M study are being included in the preparation of the new guidelines for prostate diagnostics, which are expected to be published in early 2019.
 
See also: https://www.radboudumc.nl/nieuws/2017/binnen-twee-weken-diagnose-prostaatkanker
 
Read more about the diagnosis of prostate cancer in our dossier on the website: https://www.radboudumc.nl/nieuws-en-media/dossiers/uitgelichte-onderwerpen/prostaatkanker

Jelle Barentsz is member of theme Urological cancers.