Prostate biopsy: how it's done and what's involved
Posted Sep 17 2008 1:40am
A biopsy of the prostate is a surgical procedure in which (usually) several small sections of prostate tissue are removed from the prostate for microscopic examination.
A biopsy will often be recommended if a digital rectal examination (DRE) reveals a lump or some other abnormality in the prostate. It may also be recommended if a prostate specific antigen (PSA) test suggests an abnormal level of PSA in the patient’s blood (based on his age and other factors).
In theory, there are three possible ways to perform a prostate biopsy:
By inserting a biopsy needle into the prostate through the wall of the rectum
By inserting a biopsy needle into the prostate through the perineum (the area between the base of the penis and the rectum)
By cystoscopy, in which tissue may be removed as part of a transurethral resection of the prostate (carried out as a treatment for benign prostatic hyperplasia)
In the United States, the first of these three methods is by far the most common prostate biopsy procedure today.
Before the procedure is performed, the patient may be given a sedative to help him relax; he may be asked to have an enema before the biopsy is carried out; and he will normally be asked to take a short course of antibiotics to prevent any possible infection.
Transrectal Biopsy of the Prostate
Today this procedure is usually carried out in the office of an experienced physician such as a urologist. However, it can also be carried out in the hospital operating room. It is usually carried out today with the accompanying use of a local anesthetic.
The patient is asked to lie in one of several possible positions. The physician normally uses a special prostate biopsy “gun” to drive ultra-fine biopsy needles (about half an inch long and a sixteenth of an inch in diameter) through the wall of the rectum and into the prostate. This gun is used in combination with a transrectal ultrasound “probe,” which enables the doctor to “see” where the biopsy needles are being placed into the prostate. Each hollow needle will remove a “core” of prostate tissue in about a second.
This entire procedure, properly called transrectal ultrasound-guided prostate biopsy or TRUS-guided biopsy is usually completed in about 20 minutes, from start to finish.
The Number of Cores Removed
Many different theories exist as to the “best” way to “sample” the prostate so as to find any cancer that may be present. There are no specific prostate biopsy guidelines. In gereral, however, an experienced physician will seek to take prostate biopsy specimens as follows:
Cores from all major regions of the prostate so as to ensure complete “geographic” coverage
Cores from any region of the prostate that felt suspicious under digital rectal examination
Cores from any region of the prostate that may appear suspicious under transrectal ultrasound.
In the 1990s, it was customary to carry out what was known as a “sextant” biopsy, in which six cores were removed from regionally defined areas of the prostate and then additional samples were removed from any additional areas that looked suspicious under transrectal ultrasound or felt suspicious on DRE. More recently, however, it has become normal to extract 8-12 biopsy cores so as to have a greater likelihood of finding any cancer that may be present.
In some patients, defined by specific circumstances, what is known as “saturation biopsy” may be recommended. In a saturation biopsy the physician may remove more like 20-30 biopsy cores during any one biopsy procedure. The merits of saturation biopsy are a matter for discussion.
Adverse Effects of a Prostate Biopsy
The majority of men undergo prostate biopsy with few or no significant problems at all. However, some men do have problems. and a good physician will be sympathetic to these problems if they occur:
While many men have little or no pain associated with a prostate biopsy, for some men there can be significant pain. It is possible that such pain is associated with the biopsy needle cutting into or through nerves that run through the prostate tissue.
Minor bleeding may occur after a biopsy, with blood evident in the urine. Rectal bleeding is also a possibility. The patient should be encourage to avoid heavy work or exercise for 24 hours after a biopsy. If there is significant and continued bleeding, a patient should immediately contact the doctor’s office.
Difficult with urination is also a possible complication. In this case also, the doctor’s office should be informed immediately.
Infection associated with a prostate biopsy is a rare but possible complication. If the patient develops a high fever, and complains of chills or abdominal pain after the procedure, he should arrange to see the doctor right away.