Traditional Trans-Rectal Biopsies
If your doctor is concerned that you might have prostate cancer, you may be advised to undergo a prostate biopsy. Standard trans-rectal biopsies rely only on ultrasound imaging for guidance. During the procedure, an ultrasound probe is inserted into the rectum. Then under ultrasound guidance, a urologist passes a needle through the rectum and into the prostate gland (which is just in front of the rectum) and a sample is obtained. This is usually repeated until 6 to 12 samples are taken from the gland, and ideally from the area that is concerning for cancer.
Fusion Trans-Rectal Biopsies
Prostate cancers can be difficult to see with ultrasound, and that is where an MRI scan of the prostate can be helpful. An MRI allows for more precise identification and targeting of any worrisome areas. At some specialized centers, urologists can then perform "fusion" biopsies, where they use sophisticated software to overlay the MRI scan onto the ultrasound images they get from a rectal ultrasound probe. By "fusing" the two image types together, they can then aim the biopsy needle at specific worrisome spots in the prostate that were identified by the MRI.
This fusion biopsy approach is revolutionizing the way prostate cancer is detected, however there are still some drawbacks to the technique. Sometimes the MRI and ultrasound images won't line up just right. Even if worrisome spots are visible on an MRI, some parts of the prostate gland can be tough to get to with the needle coming from the rectum. Also, passing the needle through the normal bacteria of the rectum and into the prostate poses a small but very real risk of urinary infection. These infections are usually minor but they can become severe. Biopsy-related infections are on the rise worldwide due to drug-resistant bacteria.
Next Generation: MRI-GUIDED PROSTATE BIOPSIES
To address these issues, we have recently become one of a few centers in the country performing true MRI-guided prostate biopsies using a special technique that avoids the rectum. We place the patient directly in the MRI scanner, and then we do an MRI scan to show us the areas we wish to biopsy. Then under actual real-time MRI guidance, we pass a small biopsy needle through the skin behind the scrotum (the "perineum") and directly into the prostate gland. We then advance the needle to the areas of concern and take tissue samples. This is known as the "trans-perineal" approach. Because it doesn't involve passing a needle through the rectum, the infection risk is substantially lower. Also, true MRI guidance allows us to directly confirm with MRI images that our needle is in the spot that we need it to be, and it also permits us to reach areas of the gland that can otherwise be tough to get. Additionally, there are some patients who have had their rectums surgically removed, and therefore can't get a prostate biopsy done any other way.
If you are a patient who would like to hear more about this exciting new approach to prostate biopsies, or if you are a physician with a patient who would benefit from such a service, please contact us for more information!