Biopsy: What is a Prostate Biopsy and How is it Performed?
The prostate biopsy is a procedure by which samples of tissue are removed from suspicious areas of the prostate gland for microscopic examination by a pathologist. A biopsy is absolutely necessary to confirm the presence of prostate cancer and should be undertaken prior to any treatment of the disease. Biopsies and pathological examination under a microscope are required to definitively diagnose any kind of cancer – skin, lung, breast, etc. A prostate biopsy also provides us with a wealth of information about the specific characteristics and grade of cancer. The microscopic evaluation provides a Gleason score, which classifies the cellular differentiation of cancerous tissue compared to normal tissue.
When performing a biopsy, the doctor will use transrectal ultrasound (TRUS) imaging for guidance in order to insert a slender needle through the wall of the rectum into the prostate gland. Doctors can also perform the biopsy through the perineum, the area between the rectum and scrotum. The needle removes a tiny core of tissue (usually measuring about 1/2-inch by 1/16-inch) that is sent to a laboratory to see if cancer is present. Although the procedure may sound painful, for most men, a biopsy causes little discomfort because it is performed with an instrument called a biopsy gun, which inserts and removes the needle in a fraction of a second. In addition, a local anesthetic can be used to numb the area. Patients are advised to confirm this with their doctor prior to the procedure in order to know what to expect. The procedure can be done in the doctor’s office and usually takes only about 15 minutes.
The prostate biopsy has traditionally involved obtaining at least six core samples of tissue. This technique, known as the sextant biopsy, draws two tissue samples from the base, the mid-gland and apex for a total of six core samples. Studies have shown that increasing the number of samples can significantly enhance the detection of malignancy. The number of biopsy samples taken now ranges from 6 to 18 or more. The 5-region biopsy approach obtains additional samples from the mid-gland tissue and the lateral zones or lobes on each side of the gland. When a very large number of samples are obtained (25 samples or more), this approach is called “saturation biopsy.”
Standard transrectal approach biopsies can be limited in their ability to access and sample the apical prostate (lowest portion), anterior prostate (transitional zone) and the most postero-lateral (left and right) aspects of the gland, especially with a larger gland. Therefore, we recommend a type of biopsy known as a template-guided transperineal 3-dimensional mapping (3-DMP), using 3D Color-Flow Power Doppler Ultrasound (3DCFPDU). The risk of infection is also less with the 3-DMP approach, as is extent of rectal bleeding, since the potentially “contaminated” rectal wall is not pierced, while with the 3-DMP method only a Betadine cleansed (sterilized) perineum is pierced.
Other benefits of this technique include being suited for larger glands (office biopsies often miss right and left lateral lesions, where prostate cancer is common); and there is less chance of hitting a critical vessel. By utilizing 3-Dimensional Color Flow Power Doppler Ultrasound, the physician can guide the biopsy to areas of concern, unlike the literal “shots in the dark” when using standard grey-scale ultrasound imaging. The only drawback with 3DCFPDU-guided biopsy is that it is more costly because of the hospital expense. The information obtained by your biopsy will be very important in guiding your treatment decisions if your results indicate the presence of cancer. In that event, we recommend requesting a copy of the pathologist’s report for your own files. We also advise patients to obtain a second opinion on the pathology report from one of the leaders in the field, since Gleason scores are subjective and dependent on the expertise of the pathologist.
The Dattoli Team reported on the effectiveness of 3-Dimensional Color Flow Power Doppler Ultrasound-guided biopsies with an abstract research presentation at the American Society of Clinical Oncology (ASCO) Genitourinary Cancer Symposium, February 26-28, 2015. The Dattoli presentation can be viewed by clicking the link below: