MRI Guidance for Prostate Biopsies Increases Chances of Finding Aggressive Cancers
Traditionally, biopsies to detect prostate cancers rely on ultrasound guidance but a recent study published through the Washington University School of Medicine in St. Louis indicates that MRI may be a more accurate technology. Presented on May 19 at the American Urological Association meeting in Orlando, Florida, the research found a direct correlation between more accurate prostate biopsies and the use of MRI technology to guide the placement of needles.
Patients who are in a watchful waiting therapy for prostate cancer typically are given a biopsy when their PSA number rises above 4.0 ng/ml. This rise in PSA levels may indicate a growth in the tumors, and biopsies can help predict how aggressive the cancer is becoming. However, ultrasound technology cannot visualize tumors well, so urologists will randomly biopsy the prostate gland to gather tissue samples. This random process leads to a higher risk of a false negatives because the needle may have missed areas of cancer.
In the Washington University study, Dr. Gerald Andriole and radiologists from the Mallinckdrodt Institute of Radiology used MRI scans of the prostate to biopsy 70 men with PSA scores of just above 8.0 ng/ml, on average. Dr. Andriole took tissue samples from those areas that looked suspicious on the MRI, as well as any areas where the MRI was not able to visualize well . His results showed that these targeted biopsies were nearly three times as effective at finding cancer than nontargeted biopsies.In addition, they were four times more likely to detect aggressive tumors effectively, and therefore order treatment only for patients who had this disease.
The study was not perfect, however. Dr. Andriole noted that the process predicted positive biopsies around 62 percent of the time. Researchers believe, however, that improvements in MRI technology may make it an even more viable option for prostate cancer screening, allowing doctors to rule out the need for a biopsy when the MRI result is negative.