The knowledge of the extent and grade of a patient's prostate tumor is critical to choosing the proper course of treatment. Unfortunately, imaging with MRI or Color Doppler ultrasound is not sensitive or specific enough to make the critical decisions needed concerning an individual's prostate cancer management. To compound the problem, Trans-rectal Ultrasound Guided Biopsy (TRUS) prostate biopsy is also a woefully inadequate diagnostic and staging procedure. Dr. Onik's work recently presented at the Society of Interventional Radiology annual meeting (2009) in San Diego showed that with TRUS biopsy alone 70% of prostate cancer patients are inappropriately treated.

In order to solve this dilemma Dr. Onik has developed what he is calling a 3D Prostate Mapping Biopsy (3D-PMB). This prosate biopsy is different than the TRUS biopsy in a number of ways. Firstly, it is carried out through the skin of the perineum (area behind the scrotum and in front of the rectum) so the procedure is sterile and a larger number of prostate biopsy samples can safely be taken. Secondly, the prostate is biopsied every 5 millimeters throughout it's whole volume. The number of core samples taken is therefore dependent on the size of a patient's prostate as opposed to a arbitrary number as in TRUS biopsy. The prostate biopsies are guided using a brachytherapy grid (similar to playing battleship) and the specimens are sent labeled as to it's exact location. If a biopsy therefore comes back positive, the cancer's exact location in the prostate is now known so it can later be targeted for treatment. Lastly, the procedure is always carried out under heavy sedation or general anesthesia.

The results we have obtained using this prostate biopsy method have changed our thinking about the staging of prostate cancer. We have found that 50% of the patients that were thought to have only one sided cancer by TRUS biopsy actually have cancer on both sides of the gland. In addition, 25% of the patients biopsied have an increase in their Gleason score after a 3D-PMB. Many of the patient's that we see that are considering "watchful waiting" find out that in actuality they are NOT good candidates for that management strategy.

The complications associated with 3D-PMB have been minor and self limited. We feel that the information gained from the biopsy is far outweighed by any additional risk the biopsy poses. The overwhelming majority of patients therefore need a 3D-PMB prior to choosing therapy.