Published: Mar. 15, 2010
Updated: Aug. 22, 2011
In select cases, your surgeon may decide to augment the results of routine prostate biopsies performed in the clinic setting -- transrecal ultrasound biopsy (TRUS biopsy) -- with an additional procedure termed three dimensional (3-D) transperineal mapping biopsy.
The added precision of this technique will allow your surgeon to determine if focal therapy treating only the cancerous portion of the prostate is appropriate.
Approximately 1/5th of prostate cancers are localized, meaning there is only one “focal” area of cancer. The routine biopsies that are performed in clinic do not take enough tissue or sample enough areas of the prostate to determine whether a cancer is truly localized to only one area.
In this situation 3-D transperineal mapping biopsies offer additional information to determine if focal therapy is appropriate. If focal therapy is feasible, rather than having the entire prostate gland undergo therapy, it may be possible to only treat the portion of the prostate with cancer.
This has implications for potentially lowering the side effects affecting the control of urine (continence) and maintenance of erectile function (potency). Also, focal therapy can often be done as an outpatient, rarely requiring an overnight stay.
Because 3-D transperineal mapping biopsies take samples from areas of the prostate that cannot be reached transrectally -- which is the way biopsies are performed in clinic -- sometimes this technique can also be used in patients where there is high suspicion for cancer but previous biopsies have been negative.
Due to the greater number of biopsy samples as well as the more complete sampling of prostate tissue, the accuracy of detecting cancers is improved, and the likelihood of missing a clinically significant cancer is decreased.
In some patients active surveillance (sometimes referred to as “watchful waiting”) of a known prostate cancer may be chosen. This implies that the cancer can be regularly monitored during a period of time and active therapy (e.g. radical surgery, cryotherapy, radiation, etc.) deferred until the clinical characteristics change.
To more clearly ensure that the cancer is appropriate for surveillance (i.e., it is not of an aggressive Gleason grade or is of high volume) 3-D transperineal mapping biopsies could be considered, as this method is currently the best way to acquire information regarding the extent of cancer.
For men who choose active surveillance, age and overall health will determine the evaluation and follow-up schedule.
In this manner, other areas within the prostate will be sampled to ensure accounting for all cancer foci. The mapping biopsies could be used later as well for surgical/focal therapy planning if active therapy is elected.
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