Men's Health
Imaging & Interventions
Why an MRI/US fused biopsy?
A standard transrectal prostate biopsy is performed under ultrasound guidance. A total of twelve core biopsy samples are obtained from pre-determined regions of the prostate gland.
A fused biopsy enables precise targeting of a focal lesion or a more diffuse abnormality seen on a prostate MRI. Rather than blindly sampling areas of tissue, tremendous care is taken to contour the abnormality seen on the screening prostate MRI, such that it may be targeted for biopsy, significantly increasing the diagnostic yield of the biopsy and likelihood of diagnosing a clinically significant prostate cancer.
​
MRI/US fused biopsy technology also ensures that the standard 12 core prostate biopsy samples are from appropriate regions of the prostate gland. Obtaining evenly spaced core samples ensures that all regions of the prostate gland are sampled, yet again increasing the diagnostic accuracy of the biopsy.
​
During the biopsy, the ultrasound probe rests just inside the rectum. As I turn the ultrasound probe in various directions, it is as if I am moving inside the previously performed MRI in 3-dimensional space, as I am "fused".
"Prebiopsy MRI combined with targeted biopsy vs systematic transrectal ultrasonography-guided biopsy alone was associated with improved detection of clinically significant prostate cancer...Prebiopsy MRI was associated with a reduced number of individual biopsy cores taken per procedure and with reduced adverse effects...It potentially prevented unnecessary biopsies in some individuals."
M. Elwenspoek,et al. Comparison of Multiparamagentic MRI and Targeted Biopsy with Systematic Biopsy Alone for the Diagnosis of Prostate Cancer. JAMA Netw Open.2019; 2(8):e198427
Why a transperineal biopsy?
Traditional prostate biopsies are performed trans-rectally. This means that in order to biopsy the prostate gland the needle must pass through the rectal wall. Thus, with each pass of the needle bacteria from the rectum is introduced into the prostate and its blood supply. The resultant risk of post-biopsy fever is common as well as infection, occuring in 5-7% of patients, with up to 3% of patients requiring hospitalization for IV antibiotic administration.
Alternatively, during a transperineal prostate biopsy, samples are taken through the skin of the perineum, the space between the scrotum and the rectum. As bacteria is not introduced into the prostate gland, the risk of post biopsy fever and infection is essentially 0%.
​
As the biopsy needle courses along the vertical axis of the prostate gland, from apex to base, no region of the prostate gland is "off-limits" for targeting. From a transrectal biopsy approach, lesions in the anterior most aspect of the prostate gland are usually missed and beyond the reach of the biopsy needle. There is no such dilemma with a transperineal biopsy, as all territories within the prostate gland may be successfully targeted for biopsy.
During the biopsy...
Sedation is provided by an Anesthesiologist. Based on the health of the patient and presence of medical co-morbidities, the appropriate level of sedation is selected, ranging from conscious sedation to general anesthesia, however most commonly Propofol is administered.
​
Once sedated, the patient is placed on their back and the legs are elevated to expose the skin of perineum. The ultrasound probe is placed in the rectum and the needle guide rests against the perineum. Core biopsy samples of the target lesion are taken, followed by 12 evenly spaced samples throughout the prostate gland.
​
Of note, a Foley catheter is not routinely placed, and is only utilized in those patients with a large gland, greater than 100mL, due to the risk of urinary retention.
​
​
​
​
​
​
​
​
​
Dr. Wolf tells her patients that on the day of the biopsy, they will arrive in the Interventional Radiology Department, get an IV placed, meet the Anesthesiologist and be put to sleep.
For some, that is all they want to know.
Preparation for the biopsy
On the day before the biopsy...
As the ultrasound probe will rest inside the rectum during the fused biopsy, the rectum needs to be free of stool to ensure adequate visualization of the prostate gland and accurate 3-dimensional fusion.
​
​
What is a clear liquid diet?
​
Water
Gatorade
Black coffee
Broth (no vegetables/meat)
Jello (any color)
Popsicles
​
​
You may have a normal breakfast and only clear liquids for lunch and dinner.
You may have nothing to eat or drink after midnight the night before the biopsy due to procedural sedation.
On the day of the biopsy...
At home, prior to coming to the hospital, you will do a Fleet's Enema to remove any stool from the rectum. This may be purchased over the counter at the drug store.
Care after the biopsy
A dressing made of gauze and paper tape will be placed on the perineum at the conclusion of the biopsy. As this is a challenging area to bandage, it may fall off. If so, it does not need to be replaced. If the dressing is still in place 24hours after the biopsy, it may be removed and the patient may shower.
​
Acetaminophen (Tylenol) may be used for any discomfort from the biopsy, and by the following afternoon, men usually feel "back to being themselves" and return to work.
​
Hematuria is common and expected to last for 3-5 days, while blood in the semen or ejaculate will last for several weeks.
​
Biopsy results will be available 5-7 days after the procedure. Dr. Wolf personally reviews all biopsy results and pathology reports prior to faxing them to the referring physician, ensuring that they are concordant with the initial MRI.
​
​