The Best Prostate Biopsy – Live at the AUA 2014
A Transrectal Ultrasound prostate biopsy (TRUS Bx) is performed using a probe inserted into the rectum. The probe transmits sound waves through the rectal wall toward the prostate gland. The waves bounce off of different kinds of tissue, and register as black-and-white images on a computer monitor. Although abnormal prostate tissue may show up differently than normal tissue, information about the true nature of the abnormality is limited.
According to Dr. Peter Pinto (NCI), speaking here at the American Urology Association meeting, up to 60% of “suspicious lesions,” meaning areas that look like cancer in an ultrasound, are negative and not cancerous.
Thus, a TRUS Bx is considered a “blind” biopsy – meaning physicians must randomly sample the prostate. This is an approach that has been in use since the 1980s and is still the standard form of performing this procedure.
TRUS Bx lacks precision and often misses ‘bad cancers,’ leading to under-diagnosis. In the newer Magnetic Resonance Imaging-Ultrasound Fusion method (MR/US) the patient undergoes an MRI exam before undergoing a biopsy. The MRI is much better at detecting cancerous lesions than an ultrasound. During the biopsy, the MR image is fused with ultrasound (US) imaging.
The MR/US combination guides the biopsy needle to the lesions that detected by the MRI – leading to significantly higher accuracy in finding bad cancer of the prostate.
In their presentations at the American Urology Association (AUA) meeting, Dr. Pinto and Dr Samir Taneja (NYU) presented compelling evidence suggesting significant improvement in cancer detection rates with targeted MR/US fusion prostate biopsies compared to blind biopsies.
They highlighted a study published in the European Journal of Urology, which showed that among 172 prostate biopsies, targeted biopsy detected 75.0% of all clinically significant cancers and 86.4% of Gleason sum ≥7 cancers compared to the standard (blind) biopsy. (Wysock et al 2013).
Challenges with MR/US fusion prostate biopies
It may be a challenge to find physician’s performing targeted biopsies across the U.S and the world at large. Community physicians are particularly unlikely to use this newer technique for collecting prostate tissue since there is a relatively steep learning curve and higher cost associated with MR/US fusion biopsies. Lastly, targeted biopsies require a team effort among urologist, radiologist and pathologist.
In order to perform these MRIs and interpret the resulting images correctly, radiologists need a specialized skill set specific to the prostate. In other words, a radiologist who typically looks for cancerous lesions on the breast may be under-qualified to adequately find lesions of the prostate.
My Take On This
I attract many patients who are (understandably) reluctant to undergo biopsies despite their high PSA score. Prostate biopsies are no fun, to put it lightly.
However, at this time, the gold standard way of diagnosing a man with prostate cancer is by obtaining prostate tissue. And that’s it. So when there is suspicion of prostate cancer and a biopsy is required, it makes sense to undergo the best biopsy possible. As of now, the best type of prostate biopsy is the MR /US fusion method.
Current medical institutions performing targeted MR/US fusion biopsies include:
NYU Smilow Comprehensive Prostate Cancer Center – main urologist performing this technique, Dr. Samir Taneja
National Cancer Institute department of Urology – main urologist performing this technique, Dr. Peter Pinto
UCLA Urology – main urologist performing this technique, Dr. Leonard Marks
This list is incomplete as I am still learning about groups performing MR/US fusion prostate biopsies.
Stay tuned for more Prostate Cancer AUA updates.
Wysock JS1, Rosenkrantz AB2, Huang WC1, Stifelman MD1, Lepor H1, Deng FM3, Melamed J3, Taneja SS4. A Prospective, Blinded Comparison of Magnetic Resonance (MR) Imaging-Ultrasound Fusion and Visual Estimation in the Performance of MR-targeted Prostate Biopsy: The PROFUS Trial. Eur Urol. 2013 Nov 8.